The Calming Effect of Horses
The Calming Effect of Horses
Wednesday 18th September 2019
There are many benefits of horse riding for children with autism. Autistic people see, hear and feel the world differently to other people and this can cause considerable anxiety.
The rhythmic movement experienced during horse riding has been found to calm this distress and the actual physical contact with the horse may also help to build other relationships and reduce negative reactions.
Communication and empathy may also be increased by the interaction with the horse as their excitement of riding encourages them to speak to their horse and they begin to understand that their reactions can have an impact on how the horse behaves.
Riding different horses, introducing new activities and the rotation of volunteers that help out during riding sessions can assist with the resistance to change that is often associated with autism.
Cameron Branchett has riding been since 2011. When he began to get frustrated with his progress, Malvern Riding School, an Accessibility Mark accredited centre, stepped in to help. Here his Dad, Jonathan, tells his story.
Cameron's Story
Cameron was diagnosed with Autism Spectrum Disorder (ASD) in December 2006. In 2011, after discovering that the rocking motion on the pelvis when riding a horse released oxytocin that can help calm people, Cameron tried his first riding lesson.
The effect on him was immediate. Trying to cope in a main stream school, Cameron was showing symptoms of Tourette's Syndrome alongside his ASD. All of this stopped every time he sat on the horse.
He was hooked and we were amazed that a half hour lesson could have such a profound effect on him. They say certain animals have an affinity with humans and this is certainly the case with every horse Cameron has ridden. He forms a genuine bond with them all and they seem to instinctively understand his needs.
With ASD comes difficulties, listening to and understanding complex sets of instructions can be challenging at times. Cameron never expressed any desire to be a champion rider, or show jumper, he just enjoyed riding and trotting.
However, he began to get frustrated with his own limited progress and was starting to find the lessons troubling. In 2016, he was on the verge of giving up. That's when we turned to Malvern Riding School. Julie and the staff there are simply wonderful.
Within a few months he had mastered his rising trot, something he had never managed in five years! He now canters and jumps with ease and he is so much more confident and enthusiastic about his riding now and determined to become as good as he can be to help him with his dream of becoming an actor.
Julie and the staff, have a way of sensing when Cameron is getting a little disengaged with his riding and quickly change the lessons to keep him interested.
The way they communicate with him really resonates and he responds well to them. The little things like stopping the horse and talking towards him rather than shouting to his back as he rides past make all the difference. They also know the best way to challenge and support him even when he doubts himself.
There are currently 53 Accessibility Mark-approved centres across the country.
To find your nearest RDA Group or Accessibility Mark centre visit
In other news: Activity Alliance releases updated profile toolkit


Ammonia vs. Bleach – The Difference Between
What is the difference between ammonia and bleach?
Ammonia and bleach are both cheap and effective cleaners. They are not the same, but few people really know the differences between them. Most expensive cleaners use either ammonia or bleach, so this will tell you that they are different chemicals. Both must be diluted with water in order to use safely, but it is important that you know the difference between them.
On the periodic table of elements, ammonia is known as NH3. This means that it contains 1 atom of nitrogen and 3 atoms of hydrogen. In industry, ammonia can be produced by forcefully combining these four atoms, but it does exist in its natural state in the environment. It is formed when organic material decomposes.
Ammonia can be used to clean any surface without harming the color of the surface. In everyday use, it is one of the best cleaners you can use for tiles and hard surfaces.
Bleach is a very common cleaner used to take stains off fabrics and can even be used on dishes. You must dilute bleach in order to use it because it can burn the skin. Oxidizing bleach is often used to lighten the colors of clothing and fabrics. It does this by breaking down the chemical bonds that form the color. You can make your own bleach by combining chlorine, caustic soda and water. Because of its ingredients and strength, it is commonly used as a disinfectant.
 - Ammonia and bleach are inexpensive cleaners to use in the home, especially on surfaces and items that are hard to clean.
 - They must be diluted in water before you can use them safely.
 - You cannot mix the two together because the combination produces an odor that is highly toxic.
 - Bleach can be used on white fabrics, but you must be careful with colored fabrics because it will take out or lighten the color.
 - Ammonia does not affect the color of any item.
 - Ammonia is made up of 1 atom of nitrogen and 3 atoms of hydrogen.
 - Ammonia can exist in nature.
 - Bleach is made from chlorine, caustic soda and water.


Home > Car Loans > Residual Value or a Balloon Payment Explained
Residual Value or a Balloon Payment Explained
Jacaranda Team
Jacaranda Team
January 15, 20215 minute read
Quality Checked
Taking out loans for various reasons is a smart option in around many parts of the globe, including Australia. The decision to get an advance goes with other choices, such as whether to get a residual value or not. Under certain situations, there is provision for borrowers to use a residual repayment option. Those situations majorly concern leasing of vehicles. Usually, the terms residual and balloon occur interchangeably in financial jargon. You may stumble across some of such terms when talking about loans or leases. Residual values and balloon loans are about to get demystified in this article.
On this page:
 What is a residual value?
 The residual value of a car is suitable for addressing car leases. The residual value refers to the worth of a leased car after the lease period. We all know that vehicles depreciate by a certain percentage over years of usage. Thus there is inevitable depreciation on the worth of the car would be higher before taking a lease than after. The residual value is in a place to tell us that price difference and what the new figure is. This value plays a vital role in the determination of the monthly payments towards the lease. Car lenders or leasers often determine the exact residual value, but there are specific guidelines put in place by the Australian Taxation Organisation (ATO). These guidelines spell out the least amount the residual value of a car can stand at after each year after the lease expires.
 The following are the guidelines put in place by the Australian Taxation Organisation (ATO): For a car lease of 1 year, the minimum residual value will be 65.63% of the original value; for a car lease of 2 years, the minimum residual value will be 56.25% of the actual value; for a car lease of 3 years, the minimum residual value will be 46.88% of the original value; for a car lease of 4 years, the minimum residual value will be 37.5% of the actual value; for a car lease of 5 years, the minimum residual value will be 28.13% of the original value. As is seen from the ATO guidelines, there is a steady and constant decline in the minimum percentage residual value as the years' increase. The monthly payments towards the lease are lower because of the residual value of the car.
 What is a balloon payment?
 A balloon payment is useful for both car loans and car leases. It also deals with the idea of "residual". It is the amount of money which has remained after the majority of the funds or payments are complete. When you take out and loan or a lease, you are required to make regular payments (usually monthly but it subject to the terms of the loan contract). When a balloon payment is involved in the loan, there will also be a specified amount you would need to pay after the loan or lease has expired to retain or acquire full ownership of the vehicle in question. Whenever there's a balloon payment request at the end of the loan, the regular repayments reduce. Balloon payments and residual values can work hand in hand on the same projects.
 Similarities between residual values and balloon payments
 Both the residual value and the balloon payment work with specified quantities after the period of an advance. The two terms refer to an amount paid after the extermination of a lease or loan. While balloon payments are predominately applicable when talking about a loan, and residual values when talking about leases, they both specify that their operations occur at the end of the agreeable debt.
 They both lessen your monthly payments towards your car. Whenever either of the factors into debts, they have the tender to reduce the amount you pay at regular intervals up until the end. The benefit of this system is that since there is an accumulated sum at the end, it leads to freeing up some of the payment burdens and somewhat compiling them at the end.
 Having reduced payments sounds nice but also note that they attract higher interest rates. Though the monthly payments are made cheaper, you often end up spending slightly more on residual and balloon payments car loan than on a regular car loan.
 Differences between the residual value and a balloon payment
 People usually get confused as to whether there is any difference in the usage of both of these terms. Though they are quite similar, there are slight differences between the two of them. Residual values are more accurate in regards to a lease, rather than a loan. The residual value is also an estimated and approximated value of the depression the car will experience after each year. While the balloon payment is technically usable for both car leases and car loans, it tends to talk more about a loan than a lease. Balloon payments are also not a percentage of depreciation or estimated depreciation. The balloon payment is less of an approximate minimisation and more of just cutting off some repayments and piling them up at the end.
 If you have plans to sell the car after the lease for whatever reason, it is a good principle for the balloon payment not to exceed the residual value. In simpler terms, the amount you owe after the loan to be less than the value of the car after the loan. If the value of the vehicle is greater than the balloon payment, you will be at a loss after selling the car because the proceeds from the car will not be enough to cover the balloon payment. You will have to cover the balloon payment will have through some other means.
 The market (car market) is unstable and full of fluctuations. It uses many factors such as depreciation and availability of a specific make, model or year. Before applying for a loan in such an unstable world, one must fully understand all terms and conditions and their workings.
 Jacaranda Team
 Jacaranda Team
 Written by Jacaranda Team
 Reviews don't lie 🌟
 Reviews current as of June, 2021.
 Our low rates
 Our low rates
 We never charge early repayment or exit fees.
 Apply Now 🚀
 Existing client?
 Existing client?
 Manage your loan easily in one place.
 Log In
 Had a good experience?
 Had a good experience?
 Refer a friend
 Need a hand? 👋


text:
This paper shows some guidelines to improve the estimation accuracy of a navigation system, which is based on wide-field-integration (WFI) of optic flow. Optic flow is a vector field of relative velocities obtained by photoreceptors in image sensors, and WFI of optic flow enables motion estimation robust by integrating wide range of optic flow. Since the system has several attractive features (small size, light weight, and low computation), it is applicable to an autonomous control system of micro air vehicles. However, due to some restrictions of real systems, WFI of optic flow theory should be applied while considering sensor arrangement for better estimation. In this paper, first an adequate number and adequate optical-axes of image sensors are investigated. Then, a new estimation system combining a gyro sensor with WFI of optic flow is discussed by numerical simulations. Finally, the essential effect for the number of cameras are verified in experiments.
All Science Journal Classification (ASJC) codes
- Control and Systems Engineering

source: openbmb/Ultra-FineWeb


Small Business Owners Still Fumbling Online
According to research by SMB Digital Scape, the majority of small business owners are still fumbling when it comes to their online presence, and we're not just talking about maintaining social media accounts. Many small business websites are missing the basics. It seems that though many businesses have an online presence, they still aren't investing enough time, money, nor attention to optimizing it, and this is likely costing them a lot of business.
Here is a rundown of the most telling omissions:
 - 78% of small business websites do not provide an email address on their homepage. Even if the business technically has a contact email account, visitors to the site have to search to find it.
 - 90% do not provide either a map or directions on their homepage. Interested customers either have to search for the information elsewhere on the site, or they have to make the effort to access a third party service, such as Google Maps, where they can be exposed to local competing businesses.
 - 94.5% of websites provide no means of conducting a transaction online. There is no way to make and pay for an order. This can turn away people who would otherwise do business online.
 - 76% of websites do not have a privacy policy. Visitors to these sites have no way of knowing what data is being collected from them and how that data is being used.
 - 98% of small commercial websites have no spam protection. There are no captcha fields included in the site's web forms.
 - 92% of websites do not have a blog. This means there is very little new content being uploaded on to the site. This can affect how the site gets ranked in the search engines.
 - 98% of websites are not optimized for the mobile web. This fact alone can be cutting off many potential customers. According to a recent study by the Pew Research Center, 35% of American adults own a smartphone and 44% of them use their phones to serf the web.
 - 74% have no location in their meta-title. Putting location data into a website's meta-title improves website visibility among potential customers looking for locally based businesses.


Avoiding CommandBinding in the XAML Code Behind files
Yesterday I got a very good question from a colleague. Basically we were discussing the M-V-VM pattern and how it makes your XAML code behind much cleaner + your application more testable. The only thing that was annoying him was the fact that he had to do the command binding and delegate the work to the ViewModel. So he asked me, "Is there a way how I can remove the Command Binding from my code behind as well?". What he was referring to, was the hooking of Commands to the ViewModel, which would look something like this
 1: CommandBindings.Add(
 2: new CommandBinding(Commands.Search,
 3: (x, e) => vm.Search(),
 4: (x, e) => e.CanExecute = vm.CanSearch())
 5: );
And the answer is, of course you can! After all, is there something you cannot do with the mighty WPF 😛
So how can we achieve this? We have to create a class that implements the ICommand interface. Here is how the ICommand interface looks like.
 1: public interface ICommand
 2: {
 3: event EventHandler CanExecuteChanged;
 5: bool CanExecute(object parameter);
 7: void Execute(object parameter);
 8: }
Very simple isn't it! Here is the MSDN description of the methods of this interface
Defines the method that determines whether the command can execute in its current state.
Defines the method to be called when the command is invoked.
Occurs when changes occur that affect whether or not the command should execute.
So in the CanExecute we have to put the logic that checks if we can execute the command and in the Execute we put the logic that executes the command…. but what about the CanExecuteChanged event? Well here we have to hook up to the Command System. Here is a simple implementation of the ICommand.
 1: public class SearchCommand : ICommand
 2: {
 3: ViewModel viewModel;
 4: public SearchCommand(ViewModel viewModel)
 5: {
 6: this.viewModel = viewModel;
 7: }
 9: _TAG_ ICommand Members
 11: public bool CanExecute(object parameter)
 12: {
 13: return!String.IsNullOrEmpty(viewModel.SearchText);
 14: }
 16: public event EventHandler CanExecuteChanged
 17: {
 18: add { CommandManager.RequerySuggested += value; }
 19: remove { CommandManager.RequerySuggested -= value; }
 20: }
 22: public void Execute(object parameter)
 23: {
 24: viewModel.MyDataView.Filter = x => ((Person)x).Name.Contains(viewModel.SearchText);
 25: }
 27: _TAG_
 28: }
 As you can see in order to hook up to the WPF command system we have to override the default behavior of the event and register to the CommandManager.RequerySuggested like so
 1: public event EventHandler CanExecuteChanged
 2: {
 3: add { CommandManager.RequerySuggested += value; }
 4: remove { CommandManager.RequerySuggested -= value; }
 5: }
This is very important because by doing so the CanExecute method will be called when ever there is focus changed, user input etc…
Once you have a class that implements the ICommand you can expose that class in your ViewModel and databind to it in the Command property of the control you want to hook up the command to like so
 1: ViewModel property
 2: ///
 3: /// Return an ICommand that can execute the search
 4: ///
 5: public ICommand SearchByNameCommand
 6: {
 7: get { return searchByNameCommand; }
 8: }
 10: XAML to hook to that command
 11:
And that's it… No more command bindings to hook to the Command in the code behind of the XAML file! This is very cool but now I guess the next question would be, so we actually have to create a class and implement an ICommand every time??
Well the answer is HELL NO…. What I do is create a class that does all the stuff for me and then I pass a delegate for the CanExecute and another one for the Execute… as simple as this…
 1: public class SimpleCommand : ICommand
 2: {
 3: public Predicate CanExecuteDelegate { get; set; }
 4: public Action ExecuteDelegate { get; set; }
 6: _TAG_ ICommand Members
 8: public bool CanExecute(object parameter)
 9: {
 10: if (CanExecuteDelegate!= null)
 11: return CanExecuteDelegate(parameter);
 12: return true;// if there is no can execute default to true
 13: }
 15: public event EventHandler CanExecuteChanged
 16: {
 17: add { CommandManager.RequerySuggested += value; }
 18: remove { CommandManager.RequerySuggested -= value; }
 19: }
 21: public void Execute(object parameter)
 22: {
 23: if (ExecuteDelegate!= null)
 24: ExecuteDelegate(parameter);
 25: }
 27: _TAG_
 28: }
and to create a command now is as simple as this…
 1: searchByNameCommand = new SimpleCommand
 2: {
 3: CanExecuteDelegate = x =>!String.IsNullOrEmpty(SearchText),
 4: ExecuteDelegate = x => myDataView.Filter = stateObj => ((Person)stateObj).Name.Contains(SearchText)
 5: };
and yes you could say that it is a 1 line of code 😛 (well a long one maybe 🙂 )… yet of course, you can have as much logic in there as you want!
If you want to see a sample project I created a demo app that you can download here.
kick it on DotNetKicks.com
23 thoughts on "Avoiding CommandBinding in the XAML Code Behind files
 1. This is a nice article Marlon. I saw a very similar approach on a Model View ViewModel video a couple last week.
 My question is, how do you handle input gestures with this technique? How do you do to associate a shortcut to your command?
 2. Jeremy that is really a good question … yet I am not able to answer it today because I never did that… when ever I needed that I relied on the Routed Commands…. a good next post I must say 😛
 3. Pingback: 2008 November 27 - Links for today « My (almost) Daily Links
 4. Pingback: Dew Drop - November 28, 2008 | Alvin Ashcraft's Morning Dew
 5. Pingback: Visual Studio Links #86 : Visual Studio Hacks
 6. Pingback: AttachedCommandBehavior aka ACB « C# Disciples
 7. Pingback: Keep code behind clean « The Simple Part
 8. Anyone know how to write that CanExecuteChanged EventHandler in Vb.net code?
 public event EventHandler CanExecuteChanged
 {add { CommandManager.RequerySuggested += value; } remove { CommandManager.RequerySuggested -= value; }
 9. Pingback: Behaviour driven development on user interfaces with Automation peer « The Simple Part
 10. Pingback: The power of ICommand - Rudi Grobler
 11. Pingback: [MVVM + Mediator + ACB = cool WPF App] – The MVVM « C# Disciples
 12. Pingback: sachabarber.net » WPF : Attached Commands
 13. Pingback: WPF ICommand vs RoutedCommand | Grimcoder blog
 14. That CanExecuteChanged implementation bothers me a bit — CommandManager.RequerySuggested is documented as only holding a weak reference to attached handlers. Which suggests that it wouldn't work reliably in this case.
 15. Thanks so much for the great post. It removes most of the junk that we have to create a command binding in WPF. But in real application, the anonymous functions which are used as Predicate and Action are not realistic. Most of the time I have to use a function instead 🙂
 But this is really a nice post. I've learned a lot from this 🙂
 16. Pingback: WPF ICommand vs RoutedCommand | ASK AND ANSWER
Leave a Reply
WordPress.com Logo
Google photo
Twitter picture
Facebook photo
Connecting to %s


text:
The National Association of Computerized Tax Processors (NACTP) is a nonprofit association that represents tax processing software and hardware developers, electronic filing processors, tax form publishers, and tax processing service bureaus.The association represents the collaborative nature of its organizational members.
By working together, these organizations seek to achieve the following goals:
- Serve as a unified industry voice in tax administration matters.
- Promote and improve the relationship and communication between NACTP member companies and government tax agencies.
- Encourage the standardization of tax forms; the timely distribution and clarification of forms, instructions, and regulations; and the simplification of approval procedures.
- Promote the standardization and simplification of electronic filing systems.
- Promote the standardization and simplification of unemployment and withholding wage filing processing systems.
- Maintain professional standards in the computerized tax processing industry.
- Function as a nonprofit association formed for the mutual benefit of its members.


text:
aṣṭamaṅgalaArticle Free Pass
aṣṭamaṅgala, eight auspicious symbols frequently represented on Jaina ritual objects. Aṣṭamaṅgalas are common to both the Śvetāmbara and Digambara sects and are found on 1st-century-ad votive slabs and in miniature paintings, as well as being employed in Jaina worship today. In the modern Jaina temple they are seen carved on the offering stands. Women devotees also form the symbols out of uncooked rice when making an offering to the Jina images. Although there are various traditions, the eight symbols are usually considered to be (1) darpaṇa (mirror), (2) bhadrāsana (throne), (3) vardhamānaka (powder vase), (4) kalaśa (full water vessel), (5) matsyayugma (pair of fish), (6) śrīvatsa symbol, (7) nandyāvarta (an elaborated swastika), and (8) swastika.
What made you want to look up "astamangala"? Please share what surprised you most...

source: HuggingFaceFW/fineweb-edu


text:
IO-Link Device Validation (Compatible or Identical)
Use Device Validation to make your IO-Link port smart. You can link IO-Link ports to operate only when a compatible or identical IO-Link device is attached. This example illustrates:
- Port 1 – Device Validation set to identical. Identical Device Validation can only function if the IO-Link device contains a serial number.
- Ports 2, 3, and 5 – Device Validation set to compatible, which means these ports only operate if a compatible (same Vendor ID and same Device ID) IO-Link device is attached to the corresponding port.
- Port 4 – after clicking SAVE, this port is configured for compatible device validation


Most Colorful Trippy Dippy Places in the World!
Sedona, Arizona (above) is certainly colorful, but there are places in the world that are so colorful that if you don't have a camera with you, you may weep.
Russian abandoned salt mine
Russia has an abandoned salt mine that is very psychedelic!
Blue Canyon, Death Valley
Death Valley may look barren and very rocky and dead, but the geology in the area shows some extraordinary colors.
Coyote Buttes, Utah
Grand Prismatic Spring, Wyoming
This is the largest hot spring in the US and third largest in the world. It contains the colors of the rainbow. Pigmented archae along the edges of the mineral-rich water create a color prism.
YuanYang Terraces, China
These man-made rice terraces are flooded with water, change colors depending on the season and growing.
Antelope Canyon, Arizona
The Navajo name for this canyon is place where water runs through rock.
Dallol, Ethiopia
Potash, sylvite and salt mining was done here on large scale.
Lake Retba, Senegal
The high salt content in this lake attracts a saline algae that turns the water pink.
Fly Geyser, Nevada
This geothermal geyser. It is partly natural and partly not so, as some attempted well drilling created a situation combined with geothermal to create this colorful and interesting place.
Zhangye Danxia Landform - China
Sandstone and minerals combined for 24,000,000 years to create this amazing scenic and colorful place.
What makes these places so colorful and unusual? Some are artificial, like the terraces in China or the salt mines that were dug in Russia. Others have minerals, geothermal, and geologic oddities to give them life.
These are surely out of this world places worth visiting and please, don't forget the camera!


text:
Determinants of patient satisfaction in outpatient musculoskeletal physiotherapy: a systematic, qualitative meta-summary, and meta-synthesis
- Additional Document Info
- View All
Purpose: To identify and synthesise patient-identified factors that influence satisfaction with outpatient musculoskeletal physiotherapy (O-MSK).Methods: A systematic, qualitative meta-summary and meta-synthesis was conducted by accessing six electronic databases: CINAHL, Embase, MEDLINE, Scopus, Web of Science, and Wiley Online Library, from inception to March 2017. Additional studies were identified by using a "berry-picking" method. Search limits were: primary studies; English language; and involving human subjects. Qualitative peer-reviewed articles describing patient satisfaction in O-MSK were eligible for inclusion. Two reviewers critically appraised eligible studies independently using the critical appraisal of skills programme tool for qualitative studies. Extracted verbatim data of included studies were synthesised using the meta-summary and meta-synthesis by using a purpose-designed form.Results: Eleven studies were included in the article. Factors influencing patient satisfaction were grouped into six broad themes: 1) clinical outcomes; 2) physiotherapist features; 3) patient features; 4) physiotherapist-patient relationship; 5) treatment features, and 6) healthcare setting features.Conclusions: These findings suggest that patient satisfaction in O-MSK is a multidimensional construct influenced by individual patient/provider, clinical, and contextual factors. Future reviews should include a synthesis of findings from both qualitative and quantitative studies to establish a fully comprehensive understanding of this complex health phenomenon.Implications for rehabilitationPatient satisfaction in outpatient musculoskeletal physiotherapy is affected by different factors, thus reflecting a multidimensional construct;Single determinants are not sufficient to affect patient satisfaction;Patient satisfaction is influenced individual patient/provider, clinical outcomes, and contextual factors;Further studies should be designed to investigate the relationships among these factors.
has subject area


What is difference between Agricultural land and Non Agricultural (NA) land?
Add your answer...
1 Answer
A. The main difference is in the FSI (Floor Space Index) i.e. how big house can be constructed on a given piece of land. Normally for agriculture land it is 0.05 (5% )i.e. on a land of 100 sqr meter you can make a house of 5 sqr meter only. NA land FSI is normally much higher at around 0.7 (70%)to 1(100%).
This link is broken. Help us!
Thanks for your feedback!
Related Videos


text:
mining ore to extract calcium - longbayhotel.in
Method of extraction used to obtain calcium Method of extraction used to obtain calcium from its ore Products. As a leading global manufacturer of crushing
Calcium, Chemical Element - structure, reaction, water
Extraction Pure calcium metal can be made by the same method used by Davy. present in iron ore: The product formed in this reaction,
calcium extraction from its ore - simpulindonesia.org
principle of extraction of calcium from ore – principle of extraction of calcium from ore calcium extraction from its ore.. » principles of mineral processing edited by maurice c. fuerstenau and kenneth n. Get More Info.
Extracting copper from its ores - chemguide
Extracting copper from its ores. the calcium carbonate is involved in the production of the slag. An overall equation for this series of steps is:
mining ore to extract calcium - miningbmw.com
Home > Quarry and mining > mining ore to extract calcium. mining ore to extract calcium. Vale (mining company) - Wikipedia, How Is Aluminium Extracted from Its Ore?.
extraction of calcium from its ore - thepatriots.in
GCSE CHEMISTRY - Extraction of Metals - What is a How is a Metal Extracted from its Ore? The method used to extract a metal from its ore, calcium, magnesium
IRON AND STEEL - chemguide
Loss of landscape due to mining, processing and transporting the iron ore, coke and limestone. Noise and air pollution (greenhouse effect, acid rain) involved in these operations. Extracting iron from the ore. Think about: Loss of landscape due to the size of the chemical plant needed. Noise. Atmospheric pollution from the various stages of
method of extraction used to obtain calcium from its ore
The greater the ease with which an element loses its electrons and acquires a positive the more reactive a metal, the more difficult it is to extract from its ore. points with regard to the method of metal extraction and reactivity towards acids. forming the moderately soluble alkali calcium hydroxide and hydrogen gas.
extraction of calcium from its ore - venustechnologies.in
how to extract magnesium from its ore | Solution for ore, Magnesium is extracted from its ores by one of two process, sulfates of metals such as calcium,, Posts
calcium extraction from its ore – Grinding Mill China
The way in which a metal is extracted from its ores is related to its Extraction of iron from iron ore. with sand in the ore to form calcium » More detailed. extraction of lithium from ore. extraction of lithium from its ores has combined with and is extracted from its Lithium. Li. Calcium.
BBC - GCSE Bitesize: Methods of extracting metals
Methods of extracting metals. Thus the method of extraction of a metal from its ore depends on the metal's position in the reactivity series: calcium; magnesium;
- Making Iron · The Transition Metals


text:
Posted May 2, 2013 by Martin Armstrong
QUESTION: You seem to be the only person who distinguishes between a "countertrend reaction" and a "reaction". Can you illustrate the difference?
ANSWER: Reactions are typically 2 to 3 units of time regardless of the level be it daily up to yearly. They are part of the "trend" and normally count as part of the trend cyclically. A Countertrend Reaction is a move that exceeds 3 units of time. This is normally a change cyclically speaking and thus is a separate cycle altogether. This can be easily illustrated by the 1989 Crash in Japan. The decline conformed to our Pi Cycle of 31.4 weeks plus the 8 week Countertrend Reaction.


Join Our Members
Luque Rod System
Luque rods are custom contoured metal rods that are fixed to each segment (vertebra) in the affected part of the spine. The main advantage is that the patient may not need to wear a cast or brace after the procedure. The main disadvantage is that the risk of injury to the nerves and spinal cord is higher than with a some other forms of instrumentation. This is because wires must be threaded through each vertebra near the spinal column, increasing the risk of such damage. Luque rods are sometimes used to treat Scoliosis.


effects can't be discarded. Use Close instead of Cancel for primary windows.
 - Use for windows in which users can't make changes.
Alt+F4, Ctrl+F4
StopStop a currently running task and close the window. Any work in progress or side effects are not discarded.
 - Use when work in progress and any side effects can't or won't be discarded, typically with progress bars or animations.
ApplyIn owner property sheets: apply the pending changes (made since the window was opened or the last Apply), but leave the window open. Doing so allows users to evaluate the changes before closing the property sheet. In owned property sheets: don't use.
 - Use only in property sheets.
 - Provide an Apply button only if the property sheet has settings (at least one) with effects that users can evaluate in a meaningful way. Typically, Apply buttons are used when settings make visible changes. Users should be able to apply a change, evaluate the change, and make further changes based on that evaluation. If not, remove the Apply button instead of disabling it.
NextIn wizards and multi-step tasks: advance to the next step without committing to the task.
 - Use only in wizards and multi-step tasks to advance to the next step without commitment.
 - The effect of a Next button can always be undone by clicking Back.
FinishIn wizards and multi-step tasks: close the window. If the task hasn't been performed yet, perform the task. If that task has already been performed, any changes or side effects are not discarded.
 - Use only in wizards and multi-step tasks. However, the use of Finish is discouraged because there is usually a better, more specific commit button:
 - If clicking the button commits to the task (so the task hasn't already been performed), use a specific label that starts with a verb (examples: Print, Connect, Start) that is a response to the main instruction.
 - If the task has already been performed within the wizard, use Close instead.
 - However, you can use Finish when:
 - The specific label is still generic, such as Save, Select, Choose, or Get.
 - The task involves changing a setting or collection of settings.
DoneNot applicable.
 - Don't use. Done as a command is grammatically incorrect.
Not applicable.
© 2014 Microsoft. All rights reserved.


text:
The American Veterinary Medical Association (AVMA) has released a new video promoting its policy on how to reduce pain for cattle during a common surgical procedure—dehorning.
Many breeds of cattle have horns, which are often removed early in life to protect other animals and farmers from injury. The AVMA policy and this informational video offer guidance to help make this procedure as comfortable as possible for animals.
"The AVMA provides up-to-date and accurate information about ensuring good animal welfare. Videos like this one help us get that information to more people," explains Dr. Cia Johnson of the AVMA Animal Welfare Division, who appears in the video. "America has more than 96 million head of cattle, so—although not widely known—this is a common procedure. The AVMA Animal Welfare Committee uses the latest scientific research available and practical experience to recommend policy for the Association. Research has shown that local anesthesia can be used to reduce the pain experienced by animals during dehorning."
AVMA policy recommends that, to reduce discomfort for the animal, dehorning be done at the earliest age possible and that consideration be given to the use of local anesthetics (e.g., lidocaine) and nonsteroidal anti-inflammatory agents for pain control.
The new video demonstrates the use of local anesthetic and disbudding (a dehorning technique applied to young calves), and helps educate farmers and the general public about how pain management can improve an animals' welfare.


is returning all of the contacts that it has knowledge of.
This is a primitive operation, not an iterative one.
The name of this RPC is misleading. Even if the key to the RPC is the nodeID of an existing contact or indeed if it is the nodeID of the recipient itself, the recipient is still required to return k triples. A more descriptive name would be FIND_CLOSE_NODES.
The recipient of a FIND_NODE should never return a triple containing the nodeID of the requestor. If the requestor does receive such a triple, it should discard it. A node must never put its own nodeID into a bucket as a contact.
A FIND_VALUE RPC includes a B=160-bit key. If a corresponding value is present on the recipient, the associated data is returned. Otherwise the RPC is equivalent to a FIND_NODE and a set of k triples is returned.
This is a primitive operation, not an iterative one.
Node Lookup
This section describes the algorithm that Kademlia uses for locating the k nodes nearest to a key. It must be understood that these are not necessarily closest in a strict sense. Also, the algorithm is iterative although the paper describes it as recursive.
The search begins by selecting alpha contacts from the non-empty k-bucket closest to the bucket appropriate to the key being searched on. If there are fewer than alpha contacts in that bucket, contacts are selected from other buckets. The contact closest to the target key, closestNode, is noted.
The criteria for selecting the contacts within the closest bucket are not specified. Where there are fewer than alpha contacts within that bucket and contacts are obtained from other buckets, there are no rules for selecting the other buckets or which contacts are to be used from such buckets.
The first alpha contacts selected are used to create a shortlist for the search.
The node then sends parallel, asynchronous FIND_* RPCs to the alpha contacts in the shortlist. Each contact, if it is live, should normally return k triples. If any of the alpha contacts fails to reply, it is removed from the shortlist, at least temporarily.
The node then fills the shortlist with contacts from the replies received. These are those closest to the target. From the shortlist it selects another alpha contacts. The only condition for this selection is that they have not already been contacted. Once again a FIND_* RPC is sent to each in parallel.
Each such parallel search updates closestNode, the closest node seen so far.
The sequence of parallel searches is continued until either no node in the sets returned is closer than the closest node already seen or the initiating node has accumulated k probed and known to be active contacts.
If a cycle doesn't find a closer node, if closestNode is unchanged, then the initiating node sends a FIND_* RPC to each of the k closest nodes that it has not already queried.
At the end of this process, the node will have accumulated a set of k active contacts or (if the RPC was FIND_VALUE) may have found a data value. Either a set of triples or the value is returned to the caller.
The original algorithm description is not clear in detail. However, it appears that the initiating node maintains a shortlist of k closest nodes. During each iteration alpha of these are selected for probing and marked accordingly. If a probe succeeds, that shortlisted node is marked as active. If there is no reply after an unspecified period of time, the node is dropped from the shortlist. As each set of replies comes back, it is used to improve the shortlist: closer nodes in the reply replace more distant (unprobed?) nodes in the shortlist. Iteration continues until k nodes have been successfully probed or there has been no improvement.
Alpha and Parallelism
Kademlia uses a value of 3 for alpha, the degree of parallelism used. It appears that (see stutz06) this value is optimal.
There are at least three approaches to managing parallelism. The first is to launch alpha probes and wait until all have succeeded or timed out before iterating. This is termed strict parallelism. The second is to limit the number of probes in flight to alpha; whenever a probe returns a new one is launched. We might call this bounded parallelism. A third is to iterate after what seems to be a reasonable delay (duration unspecified), so that the number of probes in flight is some low multiple of alpha. This is loose parallelism and the approach used by Kademlia.
This is the Kademlia store operation. The initiating node does an iterativeFindNode, collecting a set of k closest contacts, and then sends a primitive STORE RPC to each.
iterativeStores are used for publishing or replicating data on a Kademlia network.
This is the basic Kademlia node lookup operation. As described above, the initiating node builds a list of k "closest" contacts using iterative node lookup and the FIND_NODE RPC. The list is returned to the caller.
This is the Kademlia search operation. It is conducted as a node lookup, and so builds a list of k closest contacts. However, this is done using the FIND_VALUE RPC instead of the FIND_NODE RPC. If at any time during the node lookup the value is returned instead of a set of contacts, the search is abandoned and the value is returned. Otherwise, if no value has been found, the list of k closest contacts is returned to the caller.
When an iterativeFindValue succeeds, the initiator must store the key/value pair at the closest node seen which did not return the value.
If no node lookups have been performed in any given bucket's range for tRefresh (an hour in basic Kademlia), the node selects a random number in that range and does a refresh, an iterativeFindNode using that number as key.
A node joins the network as follows:
 1. if it does not already have a nodeID n, it generates one
 2. it inserts the value of some known node c into the appropriate bucket as its first contact
 3. it does an iterativeFindNode for n
 4. it refreshes all buckets further away than its closest neighbor, which will be in the occupied bucket with the lowest index.
If the node saved a list of good contacts and used one of these as the "known node" it would be consistent with this protocol.
Replication Rules
 - Data is stored using an iterativeStore, which has the effect of replicating it over the k nodes closest to the key.
 - Each node republishes each key/value pair that it contains at intervals of tReplicate seconds (every hour). The republishing node must not be seen as the original publisher of the key/value pair.
 - The original publisher of a key/value pair republishes it every tRepublish seconds (every 24 hours).
Expiration Rules
 - All key/value pairs expire tExpire seconds (24 hours) after the original publication.
 - All key/value pairs are assigned an expiration time which is "exponentially inversely proportional to the number of nodes between the current node and the node whose ID is closest to the key", where this number is "inferred from the bucket structure of the current node".
The writer would calculate the expiration time when the key/value pair is stored using something similar to the following:
 - find the index j of the bucket corresponding to the key
 - count the total number of contacts Ca in buckets 0..j-1
 - count the number of contacts Cb in bucket j closer than the key
 - if C = Ca + Cb, then the interval to the expiration time is
 - 24 hours if C > k
 - 24h * exp( k / C ) otherwise
The requirement that data expires tExpire (one day) after the original publication date is more than ambiguous and would seem to mean that no data can ever be republished.
In any case, the system is required to mark the stored key/value pair with an original publication timestamp. If this is to be accurate, the timestamp must be set by the publisher, which means that clocks must be at least loosely synchronized across the network.
It would seem sensible to mark the key/value pair with a time to live (TTL) from the arrival of the data, tExpire (one day) or a fraction thereof.
Implementation Suggestions
It would seem useful to add to the Contact data structure at least:
 - an RTT (round trip time) value or a set of such values, measured in ms
 - more IP addresses, together with perhaps
 - protocol used (TCP/IP, UDP)
 - NAT information, if applicable
 - whether the address is local and so reachable by broadcast
Adding an RTT or set of RTTs to the Contact data structure would enable better decisions to be made when selecting which to use.
The round trip time (RTT) to the contact could be as measured using a PING RPC or using a conventional Internet network ping.
Possible Convoy Effects
Implementors should take care to avoid convoy effects. These occur when a number of processes need to use a resource in turn. There is a tendency for such bursts of activity to drift towards synchronization, which can be disasterous. In Kademlia all nodes are requird to republish their contents every hour (tReplicate). A convoy effect might lead to this being synchronized across the network, which would appear to users as the network dying every hour.
Random Number Generation
Implementors should remember that random number generators are usually not re-entrant and so access from different threads needs to be synchronized.
Also, beware of clock granularity: it is possible that where the clock is used to seed the random number generator, successive calls could use the same seed.


text:
Date of this Version
The concept of imaging politics and professional culture are two approaches that influence and control each other in managing library performance. This research is conducted by initially looking at imaging politics that operates on aspects of academic qualifications, library accessibility, and institutional governance among three libraries. These institutional images are analyzed through three patterns of imaging politics, i.e. mirror of reality, map of reality, and simulacrum of reality, albeit this last pattern is not found. The second analysis is based on professional culture that functions as a ballacing system. Professional culture in library management shows itself as a referential standard for the performance and practices at the libraries. Both analyses are based on information sources in the form of interviews of informants, which are supported by library documents in digital formats and direct observation during interviews and a number of other visits at the study sites. Then, the third analysis focuses on relations between imaging politics and professional culture at the libraries through theoretical frameworks and other related concepts. In the process of analysis there is implicitly found different ideological orientations at the three libraries. Unfortunately, this research is not designed for this purpose, so it is interesting if there is another further research that works for the phenomena within the framework of imaging politics and professional culture at libraries.


Archiving MySQL Tables in ClickHouse
Archiving MySQL Tables in ClickHouseIn this blog post, I will talk about archiving MySQL tables in ClickHouse for storage and analytics.
Why Archive?
Hard drives are cheap nowadays, but storing lots of data in MySQL is not practical and can cause all sorts of performance bottlenecks. To name just a few issues:
 1. The larger the table and index, the slower the performance of all operations (both writes and reads)
 2. Backup and restore for terabytes of data is more challenging, and if we need to have redundancy (replication slave, clustering, etc.) we will have to store all the data N times
The answer is archiving old data. Archiving does not necessarily mean that the data will be permanently removed. Instead, the archived data can be placed into long-term storage (i.e., AWS S3) or loaded into a special purpose database that is optimized for storage (with compression) and reporting. The data is then available.
Actually, there are multiple use cases:
 - Sometimes the data just needs to be stored (i.e., for regulatory purposes) but does not have to be readily available (it's not "customer facing" data)
 - The data might be useful for debugging or investigation (i.e., application or access logs)
 - In some cases, the data needs to be available for the customer (i.e., historical reports or bank transactions for the last six years)
In all of those cases, we can move the older data away from MySQL and load it into a "big data" solution. Even if the data needs to be available, we can still move it from the main MySQL server to another system. In this blog post, I will look at archiving MySQL tables in ClickHouse for long-term storage and real-time queries.
How To Archive?
Let's say we have a 650G table that stores the history of all transactions, and we want to start archiving it. How can we approach this?
First, we will need to split this table into "old" and "new". I assume that the table is not partitioned (partitioned tables are much easier to deal with). For example, if we have data from 2008 (ten years worth) but only need to store data from the last two months in the main MySQL environment, then deleting the old data would be challenging. So instead of deleting 99% of the data from a huge table, we can create a new table and load the newer data into that. Then rename (swap) the tables. The process might look like this:
 1. CREATE TABLE transactions_new LIKE transactions
 2. INSERT INTO transactions_new SELECT * FROM transactions WHERE trx_date > now() – interval 2 month
 3. RENAME TABLE transactions TO transactions_old, transactions_new TO transactions
Second, we need to move the transactions_old into ClickHouse. This is straightforward — we can pipe data from MySQL to ClickHouse directly. To demonstrate I will use the Wikipedia:Statistics project (a real log of all requests to Wikipedia pages).
Create a table in ClickHouse:
Please note that I'm using the new ClickHouse custom partitioning. It does not require that you create a separate date column to map the table in MySQL to the same table structure in ClickHouse
Now I can "pipe" data directly from MySQL to ClickHouse:
Thirdwe need to set up a constant archiving process so that the data is removed from MySQL and transferred to ClickHouse. To do that we can use the "pt-archiver" tool (part of Percona Toolkit). In this case, we can first archive to a file and then load that file to ClickHouse. Here is the example:
Remove data from MySQL and load to a file (tsv):
Load the file to ClickHouse:
The newer version of pt-archiver can use a CSV format as well:
How Much Faster Is It?
Actually, it is much faster in ClickHouse. Even the queries that are based on index scans can be much slower in MySQL compared to ClickHouse.
For example, in MySQL just counting the number of rows for one year can take 34 seconds (index scan):
In ClickHouse, it only takes 0.062 sec:
Size on Disk
In my previous blog on comparing ClickHouse to Apache Spark to MariaDB, I also compared disk size. Usually, we can expect a 10x to 5x decrease in disk size in ClickHouse due to compression. Wikipedia:Statistics, for example, contains actual URIs, which can be quite large due to the article name/search phrase. This can be compressed very well. If we use only integers or use MD5 / SHA1 hashes instead of storing actual URIs, we can expect much smaller compression (i.e., 3x). Even with a 3x compression ratio, it is still pretty good as long-term storage.
As the data in MySQL keeps growing, the performance for all the queries will keep decreasing. Typically, queries that originally took milliseconds can now take seconds (or more). That requires a lot of changes (code, MySQL, etc.) to make faster.
The main goal of archiving the data is to increase performance ("make MySQL fast again"), decrease costs and improve ease of maintenance (backup/restore, cloning the replication slave, etc.). Archiving to ClickHouse allows you to preserve old data and make it available for reports.
Share this post
Comments (2)
 - Aurélien LEQUOY
 How you do when this table is linked with FKs, and maitain integrity with childs tables?
 February 20, 2018 at 4:46 pm


1. Check that your microphone is not muted.
2. If there is any background noise, move to a quieter area.
3. Check if the issue is happening with a specific phone number on outgoing or incoming calls.
4. Connect a compatible wired headphone that has a microphone. If the headphone works, remove them to continue troubleshooting the internal microphones.
5. Restart your phone and test your phone's microphone and speakers with any free Voice Recorder application available from Nokia Store. Record an audio clip and play the recording. If you can hear the recording, your microphone is working.
6. If the problem persists, locate your phone's microphones and check that openings are not blocked. To find the microphone openings, see your phone's user guide or search online to find the chapter: Explore the keys and parts of your phone.


text:
Definition of C. diphtheriae
1. Noun. A species of bacterium that causes diphtheria.
Generic synonyms: Corynebacterium
Group relationships: Genus Corynebacterium
C. Diphtheriae Pictures
Click the following link to bring up a new window with an automated collection of images related to the term: C. Diphtheriae Images
Lexicographical Neighbors of C. Diphtheriae
Literary usage of C. diphtheriae
Below you will find example usage of this term as found in modern and/or classical literature:
1. Emil Von Behring: Infectious Disease, Immunology, Serum Therapy by Derek S. Linton (2005)
"Although he is still often credited with having discovered C. diphtheriae, Behring for one doubted this, since not only did Klebs fail to isolate the..."
2. Biosafety in the Laboratory: Prudent Practices for the Handling and Disposal by National Research Council (U. S.) (1989)
"Agent: Corynebacterium diphtheriae Laboratory-associated infections with C. diphtheriae are documented. Pike (90) lists 33 cases reported in the world..."
3. The Oxford Medicine by Henry Asbury Christian, James Mackenzie (1920)
"... patients does not have as much significance in the diagnosis of scarlet fever as the demonstration of C. diphtheriae has in the diagnosis of diphtheria,..."
4. Pathogens of Soybean Seeds: Bibliographyby Andrew Kalinski by Andrew Kalinski (1999)
"The extensive literature of the related diphtheria bacterium will be used as a guide. Diphtheria toxin is produced by those C. diphtheriae bacteria which..."
5. The Generic Names of Bacteria by Ella Morgan (Austin) Enlows (1920)
"Buchanan (J. Bact., v. 3, No. 1, 1918, Balto., p. 55) says the type species Is C. diphtheriae, Lehmann. and Neumann...."


text:
This component belongs to the category of ForceField. This component allows to simulate springs with Polynomial stress strain behavior. If we note:
- the spring force
- the cross section (always 1.0)
- the stress-strain non-linear function
- the original length and the current length of the spring
- the point displacement
the generic non-linear force can thus be written: where is polynom as follows: and
The dedication of jacobian matrix for PolynomialSpringForceField is given below:
Note that a RestShapePolynomialSpringsForceField does exist. It will compute the same non-linear force with regards to the rest shape of one single object. To avoid Nan problems when a spring has a zero length, an exponential addition to the denominator has been added. As a result, the stress simulation is shifted compared with polynomial values, but it keeps its nonlinearity:
More details were given in the pull-request #1342.
The polynomial parameters are set as two arrays:
- polynomialDegree: describing the set of polynomial degrees for every spring
- polynomialStiffness: describing the set of polynomial coefficients sequentially combined in one vector.
The coefficients are put from smaller degree to bigger one, and the free coefficient is always zero (since for no strain we have no stress). For examples the coefficients for polynomials [3,2,4] will be put as [a1,a2,a3,b1,b2,c1,c2,c3,c4].
- firstObjectPoints corresponding to the indices of the points related to the first object
- secondObjectPoints corresponding to the indices of the points related to the second object
- compressible: indicating if object compresses without reaction force
The PolynomialSpringsForceField requires two different objects to link, which means two MechanicalObjects on which the non-linear spring will act. On the other hand, RestShapePolynomialSpringsForceField will act on one single body, i.e. one MechanicalObject.
This component is used as follows in XML format:
or using Python:
An example scene involving a PolynomialSpringsForceField is available in examples/Components/forcefield/PolynomialSpringsForceField.scn
Last modified: 15 May 2023


text:
Physical crimes informed by publicly available identity information : underreported risk or overhyped myth?
MetadataShow full item record
Vulnerabilities associated with the wide dissemination of personally identifiable information (PII) are well documented from an identity theft perspective, but reporting of identity-related crimes that result in assaults, robberies, and other physical losses has been inconsistent. This paper aims to identify gaps in existing research regarding physical crimes informed by the public availability of PII, with an emphasis on vulnerabilities created by victim self-publication of identity information through social media. A survey of media reporting regarding 111 recent incidents, or strings of connected incidents, has facilitated the establishment of rudimentary patterns in these crimes, as well as trends in reporting, both within the US and abroad. A review of pop culture commentary on the current risk environment offers insights into public perceptions of risk, and how these perceptions may be impacted by the media and entertainment industries.


text:
In January 2019, the UK Government published its Maritime 2050: Navigating the Future strategy. In the strategy, the government highlighted the importance of digitalisation (with well-designed regulatory support) to achieving its goal of ensuring that the UK plays a global leadership role in the maritime sector.
PETRAS Researchers have released a briefing document, led by Dr. Feja Lesniewska (PETRAS UCL Researcher) that has identified six IoT related security and governance challenges for UK ports.
Ports, the gateways for 95% of UK trade movements, were identified as key sites for investment in technological innovation. The government identified the potential of the Internet of Things (IoT), in conjunction with other information-sharing technologies, such as shared data platforms, and Artificial Intelligence applications (AI), to synchronise processes within the port ecosystem leading to improved efficiency, safety and environmental benefits, including improved air quality and lower greenhouse gas emissions.
The six key challenges identified in the briefing document are:
1. Adaptive Risk Management
2. Interoperability of IoT and Legacy Systems
3. Security Management Accountability
4. Due Diligence and Capacity
5. Alignment and Review
6. The Business Case
You can download the full briefing document here.
If you would to contact the Centre regarding this briefing document, please email Dr Feja Lesniewska at _EMAIL_.


text:
Project Will Bring Reclaimed Water to Clearwater Residents
A project funded by the Southwest Florida Water Management District and the City of Clearwater will bring reclaimed water to residents who live in the Skycrest area of Clearwater.
The project includes the design and construction of a high-service pump station, more than 63,500 linear feet of reclaimed water transmission lines, distribution piping, and a five-million-gallon storage tank.
The project will interconnect reclaimed water supplies from the city's three waste water treatment plants, which will provide the ability to move reclaimed water to areas of high demand, and provide for the pumping and storage necessary to service additional customers in central Clearwater.
This project is expected to provide approximately 410,000 gallons per day (gpd) of reclaimed water to nearly 500 residential and commercial reclaimed water customers in central Clearwater. The project will offset 250,000 gpd of groundwater.
This cooperatively funded effort between the District's Pinellas-Anclote River Basin Board and Clearwater is estimated to cost $10.8 million. The District will contribute 50 percent of the costs.
Construction is scheduled to begin in May 2008 and is expected to be complete by December 2010.
Reclaimed water is wastewater that has received at least secondary treatment and is used for a beneficial purpose, such as irrigation. By offsetting demand for ground water and surface water, this alternative, non-traditional water source reduces stress on environmental systems, provides economic benefits by delaying costly water system expansions, and eliminates the need to discharge wastewater effluent to surface waters.
Return to Current Edition


text:
nounMusic, chiefly North American
- Though marked pianissimo and dolce, Piano I intensifies the accompaniment of the bell effects by passing from quadruplet sixteenth to triplet sixteenth to octuplet thirty-second notes at a mezzopiano level before resuming the melody.
- It contains a recurring rhythm of sixteenth, dotted sixteenth and thirty-second notes that is difficult to discern.
- This section, as performed in the aria, is not a traditional cadenza, and the thirty-second notes, which are included exactly as noted in the original score, may disorient young flutists who tend to perform this figure as grace notes.
For editors and proofreaders
Line breaks: thirty-second note
Definition of thirty-second note in:
What do you find interesting about this word or phrase?
Comments that don't adhere to our Community Guidelines may be moderated or removed.


text: This paper analyzes the agreed and discrepant sensemaking of members of a project team. Embedded in a narratological approach to sensemaking research, we argue that before scholars may be able to understand in detail how agreements are reached and action becomes coordinated, we need first to take seriously the proposition that sensemaking occurs in the context of individuals' idiosyncratic efforts at identity construction. This, we suggest, means attending to the narratives that actors tell about their work and self both for others and their selves. The key research contribution that we make is to demonstrate how work on 'impression management' and 'attributional egotism' may be employed in order to account for discrepant sensemaking. This is important in the context of a literature that has left relatively unexplored the reasons why people interpret differently experiences they have in common.


text:
Although many people use the terms interchangeably, there is a significant difference between a nanny and an au pair.
Differences between an au pair and a nanny:
- Au pairs are, by definition, young people from overseas who travel legally to the U.S.to care for children on a cultural exchange visa. Nannies can be anyone employed to care for a child in its own home.
- Nannies can work part-time, full-time or even overtime. Au pairs working conditions are regulated by the U.S. Department of State, so there are rules that must be followed. An au pair can work up to (but no more than) 45 hours a week, 10 hours per day.
- Nanny fees vary widely depending on if they are part-time or full-time, how many children you have, and where you live. The cost of hosting an au pair can be broken down into two main parts: Fees paid to an agency for the program administration and year-round support, and a minimum weekly stipend of $195.75, paid directly to your au pair.
- Some nannies are professionally trained and are in the field as a career. Others become nannies as a temporary way to earn money while they decide on college or other career paths. Au pairs are not professionally trained but many of them have hundreds, even thousands, of hours of experience as babysitters, tutors, kindergarten assistants, camp counselors and sports instructors.
- Nannies are employees. Au pairs are not considered an employee but rather an extended family member. The term au pair means "on par".


Drexel dragonThe Math ForumDonate to the Math Forum
Search All of the Math Forum:
Math Forum » Discussions » Math Topics » geometry.college.independent
Topic: 4D Visualization
Replies: 9 Last Post: Apr 8, 1994 10:36 AM
Advanced Search
Evelyn Sander
Posts: 187
Registered: 12/3/04
4D Part 3: Minimal Surfaces
Posted: May 27, 1993 10:49 AM
Given a fixed boundary in nD, what n-1 dimensional
hypersurface with this boundary has the minimum area?
This is the question to answer in the field of minimal
surfaces, studied by Ken Brakke and John Sullivan of the
Geometry Center. In three dimensions, this question
becomes: given a boundary in 3D, such as a loop or shape
made out of wire, what is the surface with minimum area
with this wire as its boundary? The answer should be quite
familiar to everyone; the soap film formed by dipping a
wire frame in soap solution gives a surface of minimum
area with that boundary.
Sometimes these surfaces are unexpected. For example, a
tetrahedral frame makes a soap film with planes starting
at each edge, all meeting at a point in the center, whereas
a cubic frame makes a soap film with surfaces headed
towards the center but which meet at an interior square
with rounded edges. (Many science museums have soap
bubbles and frames for people to play. It is also not
difficult to make solution and wire frames.)
Although it is easy to obtain minimal surfaces, they are
mathematically difficult to describe. Even for the
simple case of a cubic boundary, there is no known
mathematical equation which describes the soap film.
Even after gaining an understanding of the mathematics,
researchers always are going back to soap films.
"Whenever I get stuck, I take out the wire frames and soap
solution again," says Brakke.
Sullivan looks at n-1 dimensional minimal
hypersurfaces in nD, where n is arbitrary. He observes
that there are hypersurfaces which are locally minimal
but not necessarily globally minimal; in other words,
two different surfaces spanning a given boundary may
have the property that each minimizes area with respect
to perturbations in a small neighborhood of each point of
the surface. For example, in 3D, given two parallel
circles as a boundary wire, one can get two different soap
films: namely, a flat disk inside each circle
separately, and a catenoid connecting the two circles.
The catenoid surface is the shape you get if you form a
surface of rotation using the St. Louis Arch, rotating
around a line above it and in its same plane.
Sullivan finds general conditions to determine which of
the locally minimal surfaces actually has the minimum
area. His conditions apply any arbitrary dimension, so
he does not actually have to work specifically with
problems in 4D.
Brakke looks at higher dimensional singularities in
minimal surfaces. Singularities are just the possible
ways in which a surface could be lacking in smoothness.
For example, in the tetrahedral boundary case, the
planes starting at the edges intersect three at a time
along lines toward the center. These lines are singular.
Also, the planes all meet at a singular point in the
The two singularities above are both mathematical cones
on some geometric object, where the cone on an object is
defined as all the lines connecting that object to the
origin. The first singularity was three planes meeting
along a line at 120 degrees. This is the cone on the
vertices of a triangle extended into 3D. The second
singularity was six planes meeting at a point. This is the
cone on a tetrahedral wire frame.
Jean Taylor proved the two types of singularities
described are the only possibilities in three
dimensions. See the article on Taylor's work in the
May/June issue of The Sciences. Thus Brakke is trying to
classify singularities for minimal hypersurfaces in
higher dimensions.
Since each dimension builds on the singularities of the
previous dimensions, Brakke concentrates his work
specifically on 4D. He has been successful; using his
program Surface Evolver to help guess possible surfaces
with singularities, then checking his guesses
analytically, Brakke proved that the 3D cone on the 2D
hypercube frame in 4D is a minimal surface. In fact, in all
dimensions higher than three the n-1 dimensional cone on
the n-2 dimensional hypercube frame is a minimal surface
with a singularity.
The new singularity, along with singularities obtained
by extending 3D surfaces to 4D hypersurfaces, is almost
the whole story in the 4D case. Brian White proved that all
possible singularities occur on flat sided cones in 4D;
the result is specific to 4D and not true in 5D. Based on
White's result, Brakke was able to show that there were
only a finite number of cases of singularities in 4D minimal
surfaces; for all but the simplex frame, hypercube frame, and one other
case, he proved that these surfaces were not minimal.
Brakke is currently trying to prove or disprove this last
case; this would complete the 4D classification.
Brakke says that even after his work in 4D, he is unable to
really visualize it. His responded with skepticism to
the idea that anyone can visualize 4D. He said, "Give them
a test. Show them a bunch of projections of similar 4D
objects and ask them which are pictures of the same
object. Show them one'side' of a 4D object, and have them
describe the other'side.' I think you'll find that
nobody can really visualize 4D. The best they can do is try
to understand a few theorems and see that the objects
obeys these theorems."
[Privacy Policy] [Terms of Use]
© Drexel University _PHONE_. All Rights Reserved.


YF S201 Arduino Water Flow Sensor Water Measurement Sensor in Pakistan
Condition: New
Availability: In Stock
Share: Faceook Twitter
SKU: B 86,IMP50,Th20,KRT115+525
Rs.300 Rs. 375
This YF-S201 sensor sits in line with your water line and contains a pinwheel sensor to measure how much liquid has moved through it. There's an integrated magnetic hall effect sensor that outputs an electrical pulse with every revolution. The hall effect sensor is sealed from the water pipe and allows the sensor to stay safe and dry.
The sensor comes with three wires: red (5-24VDC power), black (ground) and yellow (Hall effect pulse output). By counting the pulses from the output of the sensor, you can easily calculate water flow. Each pulse is approximately 2.25 milliliters. Note this isn't a precision sensor, and the pulse rate does vary a bit depending on the flow rate, fluid pressure and sensor orientation. It will need careful calibration if better than 10% precision is required. However, YF-S201 is great for basic measurement tasks!
We have as example Arduino sketch that can be used to quickly test the sensor, it will calculate the approximate flow of water in liters/hour. The pulse signal is a simple square wave so its quite easy to log and convert into liters per minute using the following formula. Pulse frequency (Hz) / 7.5 = flow rate in L/min.
 1. Model: YF-S201
 2. Sensor Type: Hall effect
 3. Working Voltage: 5 to 18V DC (min tested working voltage 4.5V)
 4. Max current draw: 15mA @ 5V
 5. Output Type: 5V TTL
 6. Working Flow Rate: 1 to 30 Liters/Minute
 7. Working Temperature range: -25 to +80℃
 8. Working Humidity Range: 35%-80% RH
 9. Accuracy: ±10%
 10. Maximum water pressure: 2.0 MPa
 11. Output duty cycle: 50% +-10%
 12. Output rise time: 0.04us
 13. Output fall time: 0.18us
 14. Flow rate pulse characteristics: Frequency (Hz) = 7.5 * Flow rate (L/min)
 15. Pulses per Liter: 450
 16. Durability: minimum 300,000 cycles
 17. Cable length: 15cm
 18. 1/2″ nominal pipe connections, 0.78″ outer diameter, 1/2″ of thread
 19. Size: 2.5″ x 1.4″ x 1.4″
Connection details:
 1. Red wire : +5V
 2. Black wire : GND
 3. Yellow wire : PWM output.
 1. YF-S201 Datasheet
 2. Example Code
Based on 1 reviews
Add a review
Khurshid Alam - March 26, 2021


Office 365 - Suggested Meetings add-in
Suggested Meetings add-in scans emails for meeting dates/times and allows you to create the meeting invitation from that email. It will send an invitation to all those involved on the email thread (sender and recipients). There is no way to "force" it to scan an email, and it does sometimes miss obvious events or highlights obvious non-events.
How does the Suggested Meetings add-in work?
The Suggested Meetings add-in is a contextual add-in that detects requested keywords or entities, such as meeting suggestions or addresses, that are in your message, and it underlines them. Please note that this add-in doesn't attempt to read or comprehend your message. Even though you might see underlined text, no information is sent to the add-in. Remember, the add-in can run only after you have given your consent to activate it, and you've selected the text underlined by the add-in.
 1. If you see text underlined like in the screenshot below, you can click on it to bring up a Suggested Meeting.
 underlined text
 2. This will bring up the Suggested Meetings pop-up window to create the event.
 Suggested Meetings pop-up
Managing add-ins
 1. You can manage the add-ins available to you by selecting the Settings | Manage Integrations.
 2. To turn off an add-in, simply uncheck the box. There are some add-ins you may not be able to turn off.
Additional Information
See Also:


1. Help Center
 2. Supported formats
Episerver XML
What is Episerver XML and how does it work for Episerver-based web applications?
File Extensions.xml
API Extension episerver
Format Options No
Import Yes
Export Yes
Pluralization supported? No
Descriptions supported? No
Episerver is a content management service provider. Episerver XML is its standard localization file format that is used to load translated/localized strings. The localized XMLs are typically saved in the "lang" folder under the web root directory. With a predefined Localization Provider, strings loaded from the XML will override default UI texts.
Each Episerver XML has at least one locale nested in the tag. Therefore, it is possible that an Episerver XML is multilingual.
Code Sample

 --- true
 This translations contains
a line-break.
 I'm a deeply nested key.
 This key is nested inside a namespace.
 Only one pluralization found.
 Wow, you have %s pluralizations!
 You have no pluralization.
 simple key, simple message, so simple.
 This translation is not yet verified and waits for it. (In some formats we also export this status)


Full employment : définition de Full employment et synonymes de Full employment (anglais)
 Publicité ▼
définition - Full employment
full employment (n.)
2.Characteristic of a country or region where all job-seekers are provided with work.
full employment
définition (complément)
voir la définition de Wikipedia
 Publicité ▼
dictionnaire analogique
Full employment
 Economic concept
What most neoclassical economists mean by "full" employment is a rate somewhat less than 100% employment, considering slightly lower levels desirable. Others, such as James Tobin, vehemently disagree, considering full employment as 0% unemployment.[2]
Rates of unemployment substantially above 0% have also been attacked by John Maynard Keynes:
– J.M. Keynes in a pamphlet to support Lloyd George in the 1929 election.
Before Milton Friedman and Edmund Phelps, Abba Lerner (Lerner 1951, Chapter 15) developed a version of the NAIRU. Unlike the current view, he saw a range of "full employment" unemployment rates. He distinguished between "high" full employment (the lowest sustainable unemployment under incomes policies) and "low" full employment (the lowest sustainable unemployment rate without these policies).
 Technical terms
 "Ideal" unemployment
An alternative, more normative, definition (used by some labor economists) would see "full employment" as the attainment of the ideal unemployment rate, where the types of unemployment that reflect labor-market inefficiency (such as structural unemployment) do not exist. Only some frictional unemployment would exist, where workers are temporarily searching for new jobs. For example, Lord William Beveridge defined "full employment" as where the number of unemployed workers equaled the number of job vacancies available. He preferred that the economy be kept above that full employment level in order to allow maximum economic production.
 Long run aggregate supply
The concept of full employment has so far been used in conjunction with the long run aggregate supply (LRAS) curve, where long run potential output is also the full employment level of output. Full employment does not mean that there is 'zero unemployment', but rather that all of the people willing and able to work have jobs at the current wage rate. Full employment is the quantity of labour employed when the labour market is in equilibrium.
The following should be understood in discussions of NAIRU: governments that follow it are attempting to keep unemployment at certain levels (usually over four percent, and as high as ten or more percent) by keeping interest rates high. As interest rates increase, more bankruptcies of individuals and businesses occur, meaning less money to hire staff or purchase goods (the making and distributing of which requires workers, which means jobs). It might also be noted that the main cause of inflation is not high employment, but rather the ability of banks to make money with little to no backing with things of value (commodities such as gold and silver are some examples), thus flooding the market with money and decreasing the value of each dollar already issued in the process, assuming the economy has not kept up to this increase in issued loans. Economists such as Milton Friedman[3] and Dr. Ravi Batra have theorized ways that a modern economy could have low inflation and near full employment (as in close to 100% of those who are not students and are healthy enough to work, and who wish to work at any given point in time), as of yet these have yet to be widely disseminated through the press or introduced by most governments. Paul Martin - former finance minister and past Prime Minister of Canada - once held that full employment could be achieved, yet let go of this idea after gaining power.
Friedman's view has prevailed so that in much of modern macroeconomics, full employment means the lowest level of unemployment that can be sustained given the structure of the economy. Using the terminology first introduced by James Tobin (following the lead of Franco Modigliani), this equals the Non-Accelerating Inflation Rate of Unemployment (NAIRU) when the real gross domestic product equals potential output. This concept is identical to the "natural" rate but reflects the fact that there is nothing "natural" about an economy.
At this level of unemployment, there is no unemployment above the level of the NAIRU. That is, at full employment there is no cyclical or deficient-demand unemployment. If the unemployment rate stays below this "natural" or "inflation threshold" level for several years, it is posited that inflation will accelerate, i.e. get worse and worse (in the absence of wage and price controls). Similarly, inflation will get better (decelerate) if unemployment rates exceed the NAIRU for a long time. The theory says that inflation does not rise or fall when the unemployment equals the "natural" rate. This is where the term NAIRU is derived.
The level of the NAIRU thus depends on the degree of "supply side" unemployment, i.e., joblessness that can't be abolished by high demand. This includes frictional, structural, and classical unemployment.
 Phillips curve
Ideas associated with the Phillips curve questioned the possibility and value of full employment in a society: this theory suggests that full employment—especially as defined normatively—will be associated with positive inflation. The Phillips curve tells us also that there is no single unemployment number that one can single out as the "full employment" rate. Instead, there is a trade-off between unemployment and inflation: a government might choose to attain a lower unemployment rate but would pay for it with higher inflation rates. In 1968, Milton Friedman, leader of the monetarist school of economics, and Edmund Phelps posited a unique full employment rate of unemployment, what they called the "natural" rate of unemployment. But this is seen not as a normative choice as much as something we are stuck with, even if it is unknown. Rather than trying to attain full employment, Friedman argues that policy-makers should try to keep prices stable (a low or even a zero inflation rate). If this policy is sustained, he suggests that the economy will gravitate to the "natural" rate of unemployment automatically.
 Structural unemployment
 Full employability
Full employability indicates an attempt by government to make people "employable" by both positive means (e.g. training courses) and negative means (e.g. cuts in benefits). It does not necessarily create full employment.
 Technical issues
Worse, the NAIRU doesn't stay the same over time—and can change due to economic policy. For example, some economists argue that British Prime Minister Margaret Thatcher's anti-inflation policies using persistently high unemployment led to higher structural unemployment and a higher NAIRU.
 United States
The United States was, as a statutory matter, committed to full employment (defined as 3% unemployment for persons 20 and older, 4% for persons aged 16 and over), and the government is, in theory, empowered to effect this goal.[4] The relevant legislation is the Employment Act (1946), initially the "Full Employment Act," later amended in the Full Employment and Balanced Growth Act (1978). The 1946 act was passed in the aftermath of World War II, when it was feared that demobilization would result in a depression, as it had following World War I in the Depression of 1920–21, while the 1978 act was passed following the 1973–75 recession and in the midst of continuing high inflation.
However, since the passage of this Act in 1978, the US has, as of 2012 never achieved this level of employment, nor has such a reservoir of public employment been created.
 Job guarantee
Some, particularly Post-Keynesian economists[5][6] have suggested ensuring full employment via a job guarantee program, where those who are unable to find work in the private sector are employed by the government, the stock of thus employed public sector workers fulfilling the same function as the unemployed do in controlling inflation, without the human costs of unemployment.
 See also
 1. ^ Sullivan, Arthur; Steven M. Sheffrin (2003), Economics: Principles in action, Upper Saddle River, New Jersey 07458: Pearson Prentice Hall, pp. 335, ISBN 0-13-063085-3, _URL_
 3. ^ "A Monetary and Fiscal Framework for Economic Stability", 1948, American Economic Review, Vol. 38, No. 3 (Jun., 1948), pp. 245-264
 6. ^ Wray, L. Randall (Aug 2001), The Endogenous Money Approach, Center for Full Employment and Price Stability, _URL_
 External sources
 - The OECD on measuring the NAIRU
 Publicité ▼
Toutes les traductions de Full employment
Contenu de sensagent
 - définitions
 - synonymes
 - antonymes
 - encyclopédie
 - definition
 - synonym
 Publicité ▼
dictionnaire et traducteur pour sites web
Essayer ici, télécharger le code;
Solution commerce électronique
Augmenter le contenu de votre site
Parcourir les produits et les annonces
Obtenir des informations en XML pour filtrer le meilleur


text:
How to use Dynamic Groups to manage your contacts
April 21, 2016
We've already explained in this post how to use dynamic groups to create groups based on specific features such as age, gender, location, etc.
This post goes further into this feature and how it can help you organize your contacts based on features, engagement and/or missing information.
Organize contacts by feature(s)
Let's say we're interested in sending a poll to contacts between the age of 15 and 18 years. To do this you first need to find the contacts meeting that age requirement.
Go to the Contacts tab and enter the following query in the search bar:
age>=15 AND age<=18
It should look like this:
In this example, 2 contacts were found fitting the age requirement. We can save these contacts as a group by clicking on Save as Group button. We can now send a message or poll to this particular group.
It is also possible to search for contacts meeting multiple criteria. Let's assume we are interested in contacts who are female, are between 15 and 18 years old and who live in Kampala. In this case we enter the following query in the search bar:
gender=female AND (age>=15 and age<=18) AND district=Kampala
Here again we can decide to save the found contacts as a group.
Organize contacts based on "engagement"
You may remember this post where we showed how to keep track of contacts' participation in RapidPro. We added an "engagement counter" which measures how often contacts participate in flows. We can use this counter to group contacts based on their level of participation using dynamic groups.
Obviously, we first need to define engagement. We could for example decide that contacts who have participated in more than 10 polls will be considered "super" contacts. Now we can search for contacts whose counter is higher than 10 by simply entering this query in the search bar:
We may also want to take the "date of last participation" into account when measuring engagement. For instance, we consider a contact a "super" contact only if he/she participated in more than 10 polls AND has participated in a poll in the last month. To do this we could use this query:
last_participation_date>22-03-2016 AND engagement_counter>10
Using this query allows us too search for contacts that have participated after 22 March 2016 and whose engagement counter is bigger than 10. Note that the last participation date has been added as a contact field which keeps track of when a contact participates last in a poll. See this post for more info.
Identify contacts missing information for follow up
In an earlier post we said that there is no need for using temporary groups in registration flows to keep track of who hasn't responded to what question. Besides using the Split by Contact field feature we can now also search empty contact fields in Contacts. To do this we can use the query missing_field="" (as in quotation marks).
For example, if we look for contacts whose gender is unknown we can use this query:
All contacts that are missing gender information will be returned, which we can save as a dynamic group, for example "missing gender group".
Now we create a simple flow asking for just gender which could look like this:
This flow can be triggered by a campaign if you use the Registration Date as reference, or you can choose the option "Start a flow in the future or on a schedule" under Triggers.
In the case of campaign:
- Go to the Campaign tab and click Create Campaign
- You name the campaign and select the group to be involved and click Ok
- You click Add Event in the next page after which you'll see this screen:
- Here you choose the option "start flow", select which flow, in our case "ask for gender flow" and indicate when the flow should be triggered using the Registration Date as reference.
- You can add as many events as you want: 10 days after registration, 20 days after registration, etc.
In case you choose to use Triggers:
- Go to the Triggers tab and click on "Start a flow in the future or on a schedule":
- In the next screen you can select which flow to trigger, the contacts to receive the flow, the start date and time of the event and whether you want the trigger to be repeated (in our case every month):
Note that as soon as a contact provides his/her gender information he/she will be taken out of the missing gender group automatically (hence the name dynamic group). So there is no need to add an action in the flow to remove the contact from this group!
- Once a dynamic group is saved, any new contact that matches the applied query will be automatically placed in that group. This means that we don't need to run the query again as the groups are updated automatically.
- Space is not allowed in the contacts search bar. For example, the "last participation date" should be entered as last_participation_date. If we're not sure how the field is named we can check under Manage Contact Fields:
- When querying contacts you can use logical comparisons which evaluate to TRUE or FALSE. You may use the equals (=), not-equals (<>), greater-than (>), greater-than-or-equal (>=), less-than (<) and less-than-or-equal (<=) operators. When comparing text values, the equals (=) and not-equals (<>) operators are case-insensitive.
- Make sure that any contact field containing a number such as age and engagement counter are defined as Numeric and date fields as Date & Time. If the format is not set right, the queries may not work! In the screenshot above we see that the "last participation date" field is defined as "Date and Time". The "engagement counter" field on the other hand is defined as Numeric:


Thursday, August 31, 2006
Performance: Block Variables Breakdown
In response to my previous blog, Chris Nokleberg noted that if we're using String#equals a lot, interning will have an additional benefit...namely because String#equals short-circuits if both String objects are ==. I had forgotten about that benefit, so I thought I'd poke around for places it might have an effect.
In digging a little, I was reminded that DynamicVariableSet, which holds block-local variables, does a linear search for retrievals and mutations. Compare that to method-local variables in Scope, for which all clients must pass an index to get or set a value. I'm not sure if there's a reason why DynVars must be retrieved by name and Scope vars can be directly's probably historical from the C code or a limitation of the current parser. In any case, a linear search could theoretically represent a performance issue accessing or modifying block-local variables. So I thought I'd run some numbers to see how frequently we have to search past the 0 value in the DynVarSet. Here's the breakdown while gem installing rake:
Count of block var retrieves from indicies 0 through 6:
So a total of 787121 block variable lookups, with percentages below:
index 0: 65.6%
index 1: 28.7%
index 2: 5.4%
...with the remainder filling out the last 0.3% of accesses
What can we learn from this? Well DynVarSet currently allocates initial space for up to 8 variables, based on someone's long-past examination of code that showed a maximum of 6 was a good estimate. The numbers above show that, for RubyGems + RDoc at least, a maximum of 3 would cover 99.7% of all cases without requiring expansion of the array, and that with a subsequent expansion to 6 slots we would cover all but 0._PHONE_% of cases. So using 6 as a maximum and always allocating 8 slots is perhaps a bit generous. More profiling on more code is warranted here, but it might be safe to drop the initial size to 3 and leave in the doubling when expanding.
It also shows us that we pay the cost of two String#equals calls for 28.7% of lookups, and pay for three in 5.4% of lookups, with higher counts statistically insignificant. So although it might seem like we're unlikely to suffer much of a performance hit because most block var lookups are at index 0, our cost to lookup or modify block variables is doubled in over a quarter of cases and tripled in a twentieth of cases. If we normalize all lookups to the same cost (X * 99.7 versus X * 139.2), that translates to a 28% performance boost for block variable lookup cost. Note that I'm not measuring block variable modifications here either, which would conceivably see a similar boost.
And of course what it doesn't show (but which we know to be true) is that if we were able to eliminate both the linear search and the call to String#equals, we'd save a very large percentage of block var lookup time, since we'd reduce it to a simple array indexing. I think it's worth exploring how we could do that--especially since we already do it for Scope in all the same places.
Isn't optimizing legacy code fun?
Performance: Inlining Strings
A while ago, we decided to inline all appropriate symbolic strings as they entered the AST. This appeared to help performance a measurable amount, presumably for two reasons:
 1. The AST would take up less space in the long term
 2. Since Strings cache their hashcodes, having each identical string in the AST be the same object would reduce the number of hash calculations.
And the numbers seem to bear it out. Here's a local rake install:
Without interning AST strings:
real 1m19.894s
user 1m18.649s
sys 0m0.920s
With interning AST strings:
real 1m15.021s
user 1m13.785s
sys 0m0.948s
So it's very this case 4-5 seconds out of 80 seconds, or about a 6% gain with interning.
However this week I realized the fallacy of the second point above. In order to intern each incoming string, Java must hash them. This causes all strings entering the AST to be hashed once anyway in order to get the interned version. In fact, it could reduce performance, since we're now forced to hash strings we might never encounter during execution.
I can't confirm that this is 100% true, but it's a reasonable theory. String.intern() is native code, but logic dictates that the fastest way to intern strings would be to use an internal hash/symbol table. So I proceeded this evening to try removing interning to see how it affected performance. I hoped to get a small gain during execution due to a large gain during parsing. The numbers above show that I lose a measurable amount overall by interning. However, I do see substantial parse performance gains:
With interning AST strings ( - t method of measuring 100 parses):
Without interning AST strings:
About 1.7 seconds out of 11, or a whopping 15% gain in parse speed without interning. AARGH.
At this point I'm leaning toward removing interning and swallowing the 6% performance hit temporarily until we can figure out where it's coming from. Logically, interning everything should only add overhead, or so my brain tells me. Where's the flaw in my logic?
My London Schedule
So here's the times and places. I want to get together JRubyists to just chat a bit at some point, and it seems like Thursday or Friday would work best. The only concrete suggestion so far is the Fitzroy Tavern on the 15th, around 6:30PM-7:00PM (thanks Damian). This works for me, and it's after the conference. Here's a goofy Google Map to Fitzroy from the conference center.
I'm also planning to attend the "Pizza on Rails" event on the 13th, so folks can find me there.
I'll keep this entry updated as things come in, so it can be used for reference.
13 September, 6:00AM: Arrival in London (Heathrow)
Other than getting checked into the hotel, I have that whole day free. I don't plan to cram for my presentation or anything, since it's not until Friday (and I don't really work that way). To avoid the lag I'll probably sleep as much as I can on the plane. Getting out and about once I get there ought to get the circadians whipped into shape.
13 September, 6:00PM: Pizza on Rails
Pizza on Rails is around 6PM, with pizza at 7PM.
14 September, 9:00AM: RailsConf Day One
The "Welcome" is at 9, and it goes straight through until 8:30PM with a lunch break from 12:30PM to 2:00PM and a dinner break from 5:50PM to 7:30PM. I'll probably try to grab meals with folks from the conf.
15 September, 9:30AM: RailsConf Day Two
Lunch break is the same as Day One, and the conf is scheduled to go through until 6PM, with "Closing Remarks" coming after that. Probably be out by 6:30, and the Fitzroy is pretty close. Maybe someone not going to the conf can get there early to scope it out.
15 September, 3:00PM: JRuby on Rails
I'm in the last set of speakers, before the final plenary session with James Duncan Davidson and Dave Thomas. I'm up against cleaning up rails, adding unicode to rails, and project management for rails. I wish I could attend the unicode session, but I'll try to grab Dominic offline.
15 September, 6:30PM: JRuby Meetup
So far I think we'll just be at Fitzroy Tavern, as mentioned at the top of this post. All are welcome...I don't fly out until 1:25PM the next day, so I can stick around for a while.
16 September 10:00AM: Departure
Given the recent TERROR scare, I'm going to be extra careful and head to the airport nice and early. I'm not particularly worried about TERROR, but I am over-cautious about giving security enough time to scour my person for soda pop and lip balm.
Thus ends my first trip to London. It's too bad it will be so short, but I have business to attend to stateside immediately after the conference. Hopefully I'll stop back in when I'm in the EU for JavaPolis.
I hope to see plenty of JRubyists in London!


text:
Polar Studies History
On Saturday, April 18th 2009 the Geology department officially inaugurated the Robert A. Pritzker Center for Meteoritics and Polar Studies. This new Collection and Research facility was funded by the Tawani Foundation with a generous grant of $7.3 million, and included a significant meteorite collection from the Planetary Studies Foundation valued at an additional $3 million.
In attendance at the ribbon cutting ceremony and polar panel on April 18 were FM Trustee and former Board Chair Robert Pritzker and Col. James Pritzker, members of Col. Pritzker's recent Antarctic expedition, representatives of the Tawani Foundation, a representative of Prince Albert of Monaco, and Board Chairman, John Canning.
The generosity of Col. James Pritzker and the Tawani Foundation enable The Field Museum to stay at the forefront of meteorite research, as well as open new avenues of research in the polar regions, including paleontology, biodiversity studies, and climate change.
- Follow Our Research
- Conservation Efforts
- Explore Our Collections
- Research Resources
- Science Podcasts


text:
Dead and buried in a grave.
More example sentences
- On April 10, 1943, Lees-Milne wrote, 'I would like this diary to entertain two or three generations ahead when I am under the sod.'
- He has property enough to make us independent but that will be valuable only, when we are under the Sod.
- Time will run to seed when we are under the sod; there'll be time enough and to spare then.
Definition of under the sod in:
- The US English dictionary