IRS Enrolled Agents vs. CPA: Which is Right for Your Tax Situation
Financial advisers and experts advertise their services every day. How can you tell which professional to hire for your IRS tax needs? Much of it depends on the specific kind of assistance you're looking for. Ideally, you should choose a professional who is best qualified to handle your money matters. Often, that means hiring a Certified Public Accountant (CPA) or an IRS Enrolled Agent (EA). But, how can you tell which one to choose for your financial needs?
Enrolled Agent and Certified Public Accountant
What's the Difference Between a CPA and an EA?
First, it helps to understand the difference between the work of a CPA and the work of an EA. A CPA is qualified to handle all kinds of accounting issues, including general ledger duties, bank reconciliations, and income statements. CPAs are also skilled in preparing income tax returns, communicating with the IRS, and representing you in auditing cases. Generally, a CPA can handle just about any kind of financial issue you have.
An Enrolled Agent, however, is primarily taught to care for matters that relate to income tax preparation and auditing. For example, if you are audited by the IRS, an EA can represent you during the process and provide you with specialized advice to help you present your case. EAs are either former IRS agents who have worked for the agency for at least five years or they are accountants who have passed an intensive, two-day examination about the regulations of the IRS tax code.
Things to Consider When Making Your Decision
Now that you know the difference between an EA and a CPA, how can you decide which one to use? Here are a few things to keep in mind as you're deciding.
 1. How often will you need assistance?
 Do you need ongoing help, possibly on a monthly basis? A CPA may be the best choice for you, because these individuals can offer regular advice and assistance on a variety of financial topics. In fact, CPAs may be an ideal choice for those who are operating a business.
 2. Are you primarily worried about tax matters?
 If your biggest worry comes at tax time, then an EA may be a better selection. Since Enrolled Agents are so well versed in the IRS tax code, they can advise you about how to avoid falling into common auditing traps and how to make sure that you are well prepared for possible tax issues in the coming year.
 3. How important is it that you develop an ongoing relationship with your adviser?
 Would you prefer to establish a long-term relationship with your accountant? If so, make sure you work with an EA or a CPA who works for themselves, rather than those who are employed for large corporations. With a self-employed professional, you're far more likely to receive a higher level of customer service and to be able to speak to the same person each time you contact the agency.
Both a CPA and an EA can be helpful in financial matters. Knowing which one will best suit your needs can help you avoid any potential troubles with Uncle Sam or the IRS.
*Image courtesy of
New Call to action


Browse data: KeyPolicyQuestion
Jump to: navigation, search
KeyPolicyQuestion > Component : Energy demand or Flood risks or Human development or Terrestrial biodiversity
Click on one or more items below to narrow your results.
Showing below up to 12 results in range #1 to #12.
 1. PQ1 (ED) (Energy demand, How will energy demand evolve particularly in emerging and mediumand low-income economies?)
 3. PQ1 (HD) (Human development, What are the key future trends in human development, such as those targeted by the Millennium Development Goals (MDGs)?)
 5. PQ2 (ED) (Energy demand, What is the mix of end-use energy carriers to meet future energy demand?)
 7. PQ2 (HD) (Human development, How are changes in the global environment likely to affect human development?)
 11. PQ3 (HD) (Human development, How is improved access to food, water and energy likely to contribute to human development?)


text:
Aims of the project
Aims are linked to ongoing exchange of ideas to progress teaching and learning in both schools.
it will be seen as successful if the frequency of meetings and exchange events trigger improvements in practice in either school. Senior managers and pupils have already gained from the links.
Background and goals
- The project was initiated at the joint initiative of the respective head teachers.
- The Head of Gartree made an initial approach which was reciprocated.
- The partnership took place during the academic year 2014/15.
- Time availability is the only real resource critical factor.
- Facilities, such as Leicester Grammar's performance spaces may be shared from time to time.
- Currently it is focussed on SMT and teaching staff.
The outcomes will be judged by review carried out by the respective heads on an annual basis. Lessons learnt and possible improvements will be judged and incorporated in future work. It is seen as a long term linkage.
All from the age of 10 to 18 may be involved. An example is the annual Mathematics challenge competition in which Garyree has entered at least one team of Year 7 pupils. The competition is run by Leicester Grammar schools mathematics staff with help from Years 12 and 13 pupils. This is a co-educational experience.
Frequency and duration
The mathematics challenge is annual event but otherwise like events are ongoing throughout the academic year.

source: openbmb/Ultra-FineWeb


text:
Watch out for these two phrases. Many students confuse them, but their meanings are actually very different. When you use "almost all (of)"/"most (of)" with a noun phrase, and "almost" with a verb phrase, the meanings can be opposite!
"Almost all (of)" means 80-99% (not all, but close to all).
"Most (of)" means more than half, maybe 55-99%.
"Most" and "almost all" are very close to each other. You can use them in similar ways. "Almost all" is a little stronger. If I say "I liked almost all of the food I ate in Taiwan," it's stronger than "I liked most of the food I ate in Taiwan." But both sentences mean that generally I liked the food I ate there.
Let's talk about "almost all (of)" and "most (of)" only with noun phrases for now. Here are some examples, with underlined noun phrases: most of my friends, almost all of the movies, most of the shops, almost all people, most kittens.
"Almost" means nearly, not quite, close to.
"Almost" goes with verb phrases very often. Here are some examples with just verb phrases,in bold: almost married, almost won the lottery, almost miss the exit, almost bought a car, almost died, almost finished eating.
Anyway, here are some examples of a sentence type where confusing "almost all/most of" and "almost" can really change your meaning:
- Almost all of the students passed the test.
Congratulations! The majority of the class members passed the test! There were 30 students and 28 received a grade of C or better. Great!
- Most of the students passed the test.
Congratulations! The majority of the class members passed the test! There were 30 students and 22 received a grade of C or better. Great!
- The students almost passed the test.
Oh, no. The students got very low scores. Their scores were close to a passing grade, but not close enough. All of the students got less than 50% on the test. They were very close to passing, but they didn't, so they failed.
(And remember to use "all of," "most," or put "almost" in the right place every time. You can't say "almost the students passed." First, this is ungrammatical. Second, the listener will be confused and not know what you meant. The listener can't guess whether you meant "almost all of the students passed," "most of the students passed," or "the students almost passed." When you're speaking English, you can often make small mistakes and still be understood, but not with this kind of phrase!)
- Almost all of the flowers died.
I went on vacation for two weeks and didn't water my 20 roses. 17 of the roses died.
- Most of the flowers died.
I went on vacation for two weeks and didn't water my 20 roses. 15 of the roses died.
- The flowers almost died.
I went on vacation. After one week, I remembered that my roses needed to be watered. I called my neighbor and asked if she'd water them. She said the flowers looked very bad! However, she took care of them until I got back. When I came back, my roses were fine. My roses came close to dying because I forgot about them.
Does it make sense? You have to be careful with this one, because you can accidentally change your meaning completely. Watch out!

source: HuggingFaceFW/fineweb-edu


AAAI Publications, Thirty-First AAAI Conference on Artificial Intelligence
Font Size:
Multiclass Capped ℓp-Norm SVM for Robust Classifications
Feiping Nie, Xiaoqian Wang, Heng Huang
Last modified: 2017-02-13
Support vector machine (SVM) model is one of most successful machine learning methods and has been successfully applied to solve numerous real-world application. Because the SVM methods use the hinge loss or squared hinge loss functions for classifications, they usually outperform other classification approaches, e.g. the least square loss function based methods. However, like most supervised learning algorithms, they learn classifiers based on the labeled data in training set without specific strategy to deal with the noise data. In many real-world applications, we often have data outliers in train set, which could misguide the classifiers learning, such that the classification performance is suboptimal. To address this problem, we proposed a novel capped Lp-norm SVM classification model by utilizing the capped 'p-norm based hinge loss in the objective which can deal with both light and heavy outliers. We utilize the new formulation to naturally build the multiclass capped Lp-norm SVM. More importantly, we derive a novel optimization algorithms to efficiently minimize the capped Lp-norm based objectives, and also rigorously prove the convergence of proposed algorithms. We present experimental results showing that employing the new capped Lp-norm SVM method can consistently improve the classification performance, especially in the cases when the data noise level increases.
Capped Lp-Norm SVM; Robust Classification
Full Text: PDF


text:
The Health and Safety Executive (HSE) has recognised that in some cases thorough examinations undertaken in accordance with the Lifting Operations and Lifting Equipment Regulations 1998 (LOLER) may lapse because of the COVID-19 pandemic and they will, therefore, take a pragmatic approach to enforcement in these cases.
This, however, depends on the duty holder (i.e. the business) demonstrating that the lapse is as a direct result of the pandemic. Furthermore, the duty holder should only use lapsed equipment if they can demonstrate it is critical for essential work and it can still be safely operated. Above all else, it's very important to remember that thorough examination of equipment remains a legal requirement, but Southalls view based on the HSE response is as follows:
- Service providers (i.e. testing companies) may not be able to visit promptly due to prioritising their visits. As a minimum duty holders should contact the provider for an update on timescales. Records (e.g. notes, emails, etc.) of this contact should be kept.
- Can the service provider offer you any further information or advice on the types of interim checks that you may be able to undertake?
- Could the service provider accommodate a video call, providing a visual overview of the equipment? Whilst would not satisfy LOLER it could be seen as a reasonable attempt to get the service provider to look over any lapsed equipment.
- Ask yourself if the use of the equipment is essential? Can alternative equipment, with a current report of thorough examination, be used instead? If possible, take out of use equipment that is beyond its LOLER and use other equipment e.g. pump trucks or sack trolleys.
- In the case of passenger lifts, can staircases be used instead?
- Where a lifting aid is in use to lift people, such as a scissor lift, is this essential for use? For example, if a bulb in a warehouse has failed, now the days are lighter can the replacement of the bulb be delayed?
- Can operations or processes be restricted or changed to lessen the need for the use of lifting equipment?
- If the thorough examination has lapsed, is the continued use of the equipment essential? You MUST be able to justify this, for example, you work in or supply to an essential industry sector?
- You need to consider the immediate degree of harm that is likely, for example, what is the likelihood that lifting equipment or the goods being lifted, could fall on to people? Also, consider matters such as if any failure could cause damage to a building.
- Is the condition of the equipment deemed acceptable from operational history and visual pre-use checks? Nobody is expecting the person carrying out these checks to have full engineering understanding, but additional items such as the visual condition of chains and forks on lift trucks could be implemented for example. Look at your previous thorough examination reports, have all of the observations or listed category defects been rectified?
- Is there an opportunity to use in-house maintenance personnel or your routine service provider to undertake some routine checks? Can the frequency of these be increased for the time being so, for example, can they be completed monthly?
- Ensure you are following your other key controls around for example lift truck use such as remaining 2m clear of the trucks as this gives you an extra level of protection in the event of there being a failure of lifting equipment.
If an engineer is able to visit, please remember that social distancing rules will apply and you will need to make arrangements to ensure that this remains the case. As part of Southalls response to the crisis, a social distancing guide has been produced to assist you in knowing what steps to take (learn more here).


Keichu's Wheel
Getsuan said to this students: 'Keichu, the first wheel-maker of China, made two wheels of fifty spokes each. Now, suppose you removed the nave uniting the spokes. What would become of the wheel? And had Keichu done thism could he be called the master wheel-maker?'
When the hubless wheel turns,
Master or no master can stop it.
It turns above heaven and below earth,
South, north, east and west.


text: The effects of unions on productivity and firm performance have been the topic of extensive research. Existing studies have, however, primarily focused on firm-level bargaining and on markets that are characterised by a small and fixed number of identical firms. This paper studies how different unionisation structures affect firm productivity and firm performance in a monopolistic competition model with heterogeneous firms and free entry. While centralised bargaining induces tougher selection among heterogeneous producers and thus increases average productivity, firm-level bargaining allows less productive entrants to remain in the market. Centralised bargaining also results in higher average output and profit levels than either decentralised bargaining or a competitive labour market. From the perspective of consumers, the choice between centralised and decentralised bargaining involves a potential trade-off between product variety and product prices.


text:
The main ingredient in Aquaphor Healing Ointment is petrolatum, an active protecting ingredient. Petrolatum sits on the skin as a semi-occlusive barrier that lets it protect itself while allowing moisture and oxygen in. Inactive ingredients found in Aquaphor Healing Ointment are mineral oil, ceresin, lanolin alcohol, panthenol, glycerin and bisabolol.Continue Reading
Aquaphor Healing Ointment is best known for keeping wounds and scars moist so they can heal, using petrolatum to form an ointment. The lanolin alcohol in Aquaphor (also known as wool wax) has cholesterol and fatty acids that help make the skin smoother. Glycerin is a natural moisturizing factor that helps to keep the wound moisturized. Panthenol, also known as pro vitamin B5, helps to condition the wound and has humectant properties. Bisabolol is derived from the chamomile plant, and it acts as an anti-inflammatory and anti-pruritic.
Aquaphor contains no perfumes, scents, preservatives or dyes. Aquaphor Healing Ointment can be used to treat new or old wounds effectively over time and with daily use. The proper way to apply Aquaphor is by cleaning the wound, applying Aquaphor Healing Ointment and then immediately applying a bandage to the wound. Aquaphor Healing Ointment is sold over the counter at major retail stores.Learn more about Skin Care


text:
The term is sometimes confused with Mesolithic, and the two are sometimes used as synonyms. Yet, when a distinction is made, Epipaleolithic is used for those cultures that were not much affected by the ending of the Ice Age and the term Mesolithic is reserved for Western Europe where the extinction of the Megafauna had a great influence on the paleolithic populations at the end of the Ice Age.
References[change | change source]
- like the Natufian culture of Western Asia (see article agriculture, origins of. (2008). In Encyclopædia Britannica. Retrieved April 10, 2008, from Encyclopædia Britannica Online).


Failure to Launch & Drug Addiction: Which Comes First?
Man seeking addiction treatment funding
"Failure to launch" describes an adult between the ages of 18 to mid-30s who lives at home with their parents and is unable to become independent mentally, physically, emotionally, and financially. Typically, these individuals struggle to transition from adolescence to a successful, thriving adulthood. Failure to launch is not a diagnosis, but rather a way to describe this population of young adults.
What is Failure to Launch?
When we talk about the word "launch," it refers to the developmental stages during childhood and adolescence when learning to become independent and developing important life skills occur in the home.
Sunspire Health
Typically, these are defined into terms like sensory motor, neuromotor, social, and learning skills, which allow a person to explore and gain skills on becoming an independent adult [1]. Part of learning to launch within society is having motivation, a passion or interest in a career, and resiliency to be able to overcome challenges and struggles.
Many individuals who struggle with failure to launch have mental health issues, such as depression, anxiety, or drug and substance addiction, keeping them from becoming fully independent. Often, they might struggle with occupational or academic failures and drop out of university. They may lack the internal motivation to try again or continue with gaining life skills.
In 2013, research was published through the U.S. Census Bureau that 36 percent of those aged 18 to 31 are still living with their parents [2]. The researchers drew conclusions that it can be connected to many factors, such as socioeconomic changes, family dynamics, and mental health issues.
The Role of Technology
Often in today's youth, the immediate is the way of the world. They are used to getting instant information and quick products. Many are used to having technology at their fingertips and use it to socialize, play, shop, and pretty much conduct all aspects of daily life.
With the rise of the Internet, many young adults are able to secure high paying jobs without a higher education degree. The National Association of Colleges and Employers reported that the average starting salary for a person with a bachelor's degree is $45,327 [2].
Based on this, many young professionals may not accept or stay in a position where they feel they are owed a higher salary.
Family mental health issues or addiction can also play a role in failure to launch. Having caretakers or parents who are addicts or unable to cope with the role of being a parent can create an environment where there is no active learning on how to become a responsible adult. When the youth has an addiction, it can also lead to the inability to move forward with their life.
Statistics on Drug Addiction in the U.S.
According to the National Survey on Drug Use and Health (NSDUH), most addictions start between the ages of 10 to 13 [3].
College girl playing guitarSuch drugs of choice are typically tobacco, alcohol, marijuana, and prescription drugs, which are all available with fairly easy access due to a parent or caretaker's use.
Also, according to the NSDUH, if use continues, the drugs become stronger and more frequent, leading to an addiction.
Addiction can be described as a chronic disease that includes drug seeking behaviors, compulsive actions, impulse control issues, and potentially harmful consequences of continued use [4].
As previous studies have shown, when drug use occurs, it alters the brain patterns and dysregulates self-control and impulse control. Meaning, that a person is more inclined to use substances.
Long-term issues with continued drug addiction can be learning issues, faulty decision-making and judgment, increased stress, difficulty or lapses in memory and behavior that is favored toward drug use [4].
Factors such biology, environment, and development all play a role in drug addiction. Regardless of how the addiction begins, it can be devastating for an individual and their family.
How Failure to Launch Relates to Drug Addiction
Many of the factors that play a role in the development of an addiction also have roots in the failure to launch condition. Which comes first though? It is hard to tell. One is a description of a generation, and the second is of a disease which affects the brain and body.
Failure to launch and drug addiction are both pieces to a larger puzzle. It is about what environment we are born into, what heritability factors we contain, and what we are taught throughout our life.
If a person does not have positive, encouraging role models, it might affect their outlook on jobs, their ability to go farther than their parents, or how they view themself. If no one in their family went to college, it could impact their ability or motivation to go to school.
If a parent or caregiver does everything for their child, it can create a sense of entitlement within the child, and a lack of ability to know how to care for himself or overcome challenges on their own.
Addiction is powerful and all-encompassing when someone is an addict. If a caregiver is an addict, then they are unable to provide the coping skills for their child to know how to enter into the adult world ready for responsibilities and independence. It can create the cycle of addiction among generations of family with continued failure to launch.
Man staring by the bridgeIn conclusion, failure to launch and drug addiction are both separate but connected. Drug addictions can start in tween or early teen years and have a biological, environmental, and social aspect to them.
Failure to launch is a learned behavior or way of being, dependent on the environment. It is not totally certain which comes first when trying to figure out the reason for a generation of individuals with failure to launch, but we know that there are various levels of factors that influence a person and family to fear engaging in independence.
[1] Fischer, R. (2015, January 20). Failure to Launch Syndrome. Retrieved June 15, 2017, from
[2] Tucson, C. (n.d.). Cottonwood Tucson. Retrieved June 15, 2017, from
[3] Abuse, N. I. (n.d.). When and how does drug abuse start and progress? Retrieved June 20, 2017, from
[4] Abuse, N. I. (n.d.). Understanding Drug Use and Addiction. Retrieved June 20, 2017, from
Published July 29, 2017
Reviewed By: Jacquelyn Ekern, MS, LPC on July 29, 2017.
Published on
About Jacquelyn Ekern, MS, LPC


text:
(Nanowerk News) Imec realized an integrated poly-SiGe-based piezoresistive pressure sensor directly fabricated above 0.13 µm copper (Cu) -backend CMOS technology. This represents not only the first integrated poly-SiGe pressure sensor directly fabricated above its readout circuit, but also the first time that a poly-SiGe MEMS device is processed on top of Cu-backend CMOS.
Polycrystalline SiGe has emerged as a promising MEMS structural material since it provides the desired mechanical properties at lower temperatures compared to poly-Si, allowing the post-processing on top of CMOS. The MEMS-last approach is the most interesting approach for CMOS-MEMS monolithic integration as it leads to smaller die areas and enables integrating the MEMS without introducing any changes in standard foundry CMOS processes. Comparing to alternative technologies, for example using the CMOS top interconnect layers to fabricate the MEMS device, poly-SiGe offers a more generic and flexible technology for above CMOS integration, thanks to the fact that the MEMS fabrication can be completely decoupled from the CMOS fabrication.
Cross-section SEM picture of the integrated sensor. At the bottom, the two Cu metal lines of the CMOS circuit can be observed. Above, the MEMS layers (the poly-SiGe membrane and piezoresistors, the oxide sealing layer and the metal interconnects) are visible.
In the past, imec already proved the potential of poly-SiGe for MEMS above-aluminum-backend CMOS integration. However, aggressive interconnect scaling has led to the replacement of the traditional aluminum metallization by copper metallization, due to its lower resistivity and improved reliability. Our results now broaden the applications of poly-SiGe to the integration of MEMS with the advanced CMOS technology nodes.
The imec integrated sensor (fully fabricated in imec) includes a surface-micromachined piezoresistive pressure sensor, with a poly-SiGe membrane and four poly-SiGe piezoresistors, and an instrumentation amplifier fabricated using imec's 0.13 µm standard CMOS technology, with Cuinterconnects (two metal layers), oxide dielectric and tungsten-filled vias. To enable above-CMOS integration the maximum processing temperature of the complete sensor, including the poly-SiGe piezoresistors, is kept below 455°C.
Moreover, an appropriate passivation layer was included to protect the electronic circuit from the aggressive etch and deposition steps needed to fabricate the MEMS devices. The CMOS circuit showed no significant deterioration after the MEMS processing. Despite the low processing temperature, the poly-SiGe piezoresistive sensor alone (250x250µm2 membrane) showed a sensitivity of around 2.5 mV/V/bar. The integrated sensor (same sensor + Cu-based CMOS amplifier underneath) showed a sensitivity of about 158 mV/V/bar, ~64 times higher than the stand-alone sensor.


text:
The aim of the study was to determine the influence of microirrigation (microjet sprinkling and drip irrigation) and organic fertilization (compost prepared on the base of sewage sludge) on a seedling vigour of one-year and two-year old Scot pine seedlings (Pinus sylvestris L.), cultivated on a post-agricultural ground with the use of zoo-melioration in two different regions. Field experiments were carried out on an experimental field in Kruszyn Krajeński (loose sandy soil of quality class VI) near Bydgoszcz and in Lipnik near Stargard Szczeciński (sandy soil of quality class IVb). The first row factor was irrigation used in three treatments: without irrigation (control), drip irrigation, microjet sprinkling. The second row factor was fertilization, used in two variants: mineral fertilization (standard applied in forest nurseries), organic fertilization (compost). The irrigation significantly increased the height and the diameter of the Scot pine seedlings. There were no significant differences in the characters of the growth between the two irrigation systems. Fertilization of Scot pine seedlings with the compost increased significantly the height of seedlings. Interaction of irrigation with organic fertilization of Scot pine seedling height and diameter was noted. Pine seedlings grown on the plots fertilized with compost under irrigation conditions were characterized by increased height and diameter. Better effects were obtained in Lipnik than in Kruszyn Krajeński. Joint effect of organic fertilization and microjet sprinkling positively influenced the density and the species number of Oribatida in Kruszyn Krajeński. The obtained results indicated that the amelioration measures used can positively influence the growth of Scot pine seedlings on a post-agricultural ground.
ul. Papieża Pawła VI 1, 71-459 Szczecin _URL_


English subtitles
← Update Solution - Intro to Computer Science
Get Embed Code
2 Languages
Showing Revision 6 created 07/06/2017 by Dejan Trajkovic.
 1. So update's going to be pretty similar to look
 2. up. So let's start by copying that code and
 3. seeing how we need to change it. So we
 4. have lookup. We're going to change it to be update.
 5. Now instead of taking a key as its input, it's going to take a key and a value.
 6. But it's not going to return anything, so we're going to get rid
 7. of the returns. Right. remember all update is doing is modifying the
 8. value of entry. So now we still have what we had for
 9. lookup, we're still getting the bucket and we want to do that.
 10. We want to make sure that we update the value in the
 11. right bucket. We still need to look through the entries in the
 12. bucket, to find if one matches. If we find one that matches,
 13. well what we did in lookup, was just return it. And update,
 14. what we want to do is change the value associated with
 15. that key. So we are going to have an assignment that replaces
 16. whatever value is there before with a new value. And now
 17. instead of returning the value, we want to stop going through the
 18. loop, and we actually are done with update, so we can
 19. return here. We found the entry, we updated the value. We
 20. also need to deal with a case where we didn't find
 21. the entry. So now we've gone through the loop enough times.
 22. When it was a look-up we just returned none. When it's
 23. an update what we want to do when the key is not
 24. already in the table, is add it. So now we're going
 25. to use, append, to add a new entry to bucket, that has
 26. the key and the value. So that's how we defined update.
 27. There's certainly lots of other ways to do it, and one
 28. thing you should be thinking about is, well this is actually
 29. very similar to look up, right. We duplicated a lot of code.
 30. Maybe there's a way to define update and lookup so
 31. we don't have to have two copies of the code,
 32. that scans through the bucket to find the right entry.
 33. We'll leave that as a homework question for this unit.
 34. For now we're going to be happy that we've got correct
 35. implementations of both lookup and update. And, let's test them.
 36. So, what we did before, we're going to replace the adds
 37. with updates, and now, the second time, what happened with
 38. the add was we added an entry, but we could
 39. never reach that entry because it had the same keyword.
 40. Now we're used update, the second time we should be
 41. updating that value, and we'll see that the lookup now produces
 42. the value 27, for the second lookup. That's good, right,
 43. the first time the value was 23. We did the update,
 44. we got 27, and we can see that the bucket
 45. only contains one entry. So this is great, we finished our
 46. implementation of the hash table. We can do updates that will
 47. either add new values to the hash table, if they don't
 48. already exist, or change the value of ones that exist. And
 49. we can do lookups and lookup will know where to look, which
 50. bucket to look in to find that key, if it exists.
 51. So this has the great property that as the number of keys
 52. increase. As long as we increase the numbers of buckets accordingly,
 53. the time to do both an update and a lookup is constant.
 54. This means the time doesn't increase even as the number of keywords increases,
 55. as long as we increase the number of buckets. So, this size of
 56. each bucket stays the same size, because the expensive cost of this is
 57. going through the elements in the bucket looking for the key that matches.


text:
Found under the "Maps" menu, these filters map each character of input to an output character or string.
A map defines a mapping for every single input character (all 256 of them). Each ASCII code is represented by a row in a grid the left column gives the ASCII code in decimal ("Dec"), the next column gives the ASCII code in Hex ("Hex"), the next column shows the ASCII representation of the character ("ASCII"), and the right hand column shows the string that it will be mapped to ("Replacement text"). Note that if the system font does not provide a definition for a particular ASCII character (as is usually the case for ASCII codes 0 to 31 and 127, but there may be more), then it is represented as a thick vertical bar. Cells that are output differently to the input are shown with a yellow background - this makes it easy to scan through the list looking for changes.
When the replacement text cannot be normally displayed, characters are displayed using an escape code e.g. \r\n is the code for a DOS end of line. Any combination of characters can be entered in this way. The right-click (or context) menu on this field supports Undo, Cut, Copy, Paste, Delete, Clear Entire Field, Select All and Select All And Copy and entering special characters.
If all the replacements are a single byte, then TextPipe will used an optimized filter which is 3 times faster than the custom case (which handles replacements of zero characters, one character or more).
A cell is Reset when it passes through unchanged i.e. the output character is the same as the input character.
All cells can be reset by clicking "Clear All".
A cell is cleared or empty when nothing is output when the character is encountered in the input stream.
All cells can be cleared by clicking "Clear All".
If the character mapping is 1:1 (i.e. each input character gets mapped to a single output character), the "Reverse" button can be clicked to form the Reverse mapping translation.
Clicking in the Scroll To field and pressing a keyboard character will cause the grid to immediately scroll to show the mapping for that character. This makes it easy to find characters when you're not sure where in the list they appear.
Open and Save
Maps can be saved to and opened from.MAP files by clicking on the Save and Open icons displayed when a map filter is selected for editing.


Improve English
When something develops, improves and changes over time we call that activity an "evolution". ECTV's Evolution also expects a development, improvement and change within you. It is a programme that brings you evolutionary facts to develop English.
Chris Wilson is the well-informed host of this programme who improve English for learners. His talent is to start with something very simple that he gradually develops to an advanced topic.
For example, a door is something you use in everyday life. It is so common that you never trouble your head about it. But Wilson does. He goes back to history and returns to the present, explaining how that door evolved over the centuries. Evolution is ideal to increase your knowledge and to improve English language.


Take the 2-minute tour ×
Recently in a seminar someone mentioned that monotone maps are equivalent to gradients of scalar convex functions, but it's not clear to me why this is true. One direction of the equivalence is straightforward but the other is not (as far as I can tell).
Definition. A map $F:\mathbb{R}^n \rightarrow \mathbb{R}^n$ is monotone on a convex set $C$ if $$(y-x)^T(F(y)-F(x))\ge0$$ for all $x,y \in C$.
One direction of the equivalence:
Prop. Let $f:\mathbb{R}^n \rightarrow \mathbb{R}$ be convex and sufficiently differentiable. Then $\nabla f$ is monotone.
Pf. Convex differentiable functions satisfy $$f(y) \ge f(x) + \nabla f(x)(y-x).$$
By choosing the points in reverse, we also have, $$f(x) \ge f(y) + \nabla f(y)(x-y).$$ Add these inequalities and rearrange to get $(\nabla f(y)-\nabla f(x))(y-x) \ge 0$.∎
Now the other direction:
Prop. Let $F:\mathbb{R}^n \rightarrow \mathbb{R}^n$ be monotone and sufficiently differentiable. Then there exists a convex function $f:\mathbb{R}^n \rightarrow \mathbb{R}$ such that $F=\nabla f$.
Pf.???
It seems like this should be easy, but I'm stuck and google/wikipedia have been of little help. I'm actually starting to doubt whether it is true.
share|improve this question
By "sufficiently differentiable", I believe you mean that the gradient exists? You assume nothing else... I think you really need more precise conditions to know what happens next, but I'm not confident about the truth behind this result. – Patrick Da Silva Feb 21 '12 at 19:26
The obvious thing to try would be $f(x) = \int_0^1 F(xt) \, dt$. A simple computation shows that $\nabla f = F$. Then maybe the monotonicity of $F$ can be used to show that $f$ is convex? – Jeff Feb 21 '12 at 20:06
_USER_ The point was to allow anyone answering to use as many derivatives as needed. I don't think it even needs a single derivative though so long as the gradient is generalized to an element of the subderivative, but this is not really important to me so feel free to assume it is smooth. – Nick Alger Feb 21 '12 at 20:28
_USER_ Yeah, so for 1D that's totally right. But does it also hold for higher dimensions? This line of thought makes me think the result may be related to the subject of integrable systems. – Nick Alger Feb 21 '12 at 20:30
Not all fields $F$ are gradients. If $F=(F_1,\dots,F_n)$ is $C^1$, a necessary condition for $F$ to be a gradient is that $\partial F_i/\partial x_j=\partial F_j/\partial x_i$for $1\le i


"Do not try to saw sawdust"
3년 전
Rule 6: Bury our dead
he phrase we will not saw sawdust in itself means that the things that are already done can not be modified or made again so that we can go around and try to solve what is already established and only exists in our minds, becoming only history that is our power to learn from it or to continue with useless attempts to fix it.
At this moment I remember a phrase you could say that we often comment in my family that "What is done, done" or "What happened last" among others.
So we do not submit to an ordeal of worries for long months that will only bring us diseases, do not think about things we have done and wish we had done them in a better way or in a different way and regret about it.
What do we get out thinking about that?
Nothing Truth, therefore "We never cry about spilled milk", instead we have the courage and the will to be able to save that milk with a little attention and care, however it is too late to be able to make something when it is already spilled, the only prudent and best we can erase it and forget it to move on to the next step:
"Improve our mistakes"
Since: "If a person is not making mistakes is that he is not innovating, and if a person is making the same mistakes is that he is not learning anything"
In short, we learn from those mistakes and stop suffering from the spilled milk, we project against each other plans for the future doing things in which we are better, because that alone will bring us true happiness, always looking forward to repair our damage. And in any case, all the powers of the world are not capable of fixing what already belongs to the past.
Let's remember:
"Do not try to saw sawdust"
Authors get paid when people like you upvote their post.


Something hard to break - Crossword Clue
Below are possible answers for the crossword clue Something hard to break.
5 letter answer(s) to something hard to break
 2. excessive use of drugs
 3. a distinctive attire worn by a member of a religious order
 4. put a habit on
 5. attire that is typically worn by a horseback rider (especially a woman's attire)
Other crossword clues with similar answers to 'Something hard to break'
Still struggling to solve the crossword clue 'Something hard to break'?
If you're still haven't solved the crossword clue Something hard to break then why not search our database by the letters you have already!


text:
Importing data using the templates within CRM makes the import process very smooth and easy. You are able to see all of the required information that needs to be filled in prior to importing the data. You are able to import data to appropriate fields within CRM since the fields also get mapped automatically to the desired fields.
Templates are available for all entities.
You are able to access these download templates by following the steps below:
- You can find the template on the ribbon of the entity itself
- Or you can click on SettingsÃ Data ManagementÃ Templates for Data Import
- You are able to select the entity you want to import the data for
- The file saves as a.xml file on your computer
- Open the file and fill in the appropriate information
- All the fields that are bolded are required fields
- You just need to fill in the information that you want to see in your CRM form when you open the entity
- As for the lookup fields, such as the Primary Contact and Parent Account, you can add them there only if they already exist in CRM
Save the file â€" keep the xml format because it automatically maps the correct fields
The file formats that are supported by CRM are Comma-separated values (.csv), Text (.txt), Compressed (.zip), and Excel Spreadsheet 2003 (.xml)
You can import the file by clicking the import button from the ribbon or by digging into the settings area:
Click on the import button on the ribbon
Click on SettingsÃ Data ManagementÃ ImportsÃ Import Data
Select the file â€" if you do the.xml format, the entity and the fields will map automatically
You can find your imported file within the imports section
You can now import your files rather than entering endless amount of data manually one by one.
I hope you found this blog helpful! Check out out our other Dynamics CRM resources like our CRM Book for even more great information!


text:
A SelectorMap encapsulates a number of Regions that all have the same number of axes and represent the same coordinate Frame. The number of inputs (Nin attribute) of the SelectorMap equals the number of axes spanned by one of the encapsulated Region. All SelectorMaps have only a single output. SelectorMaps do not define an inverse transformation.
For each input position, the forward transformation of a SelectorMap searches through the encapsulated Regions (in the order supplied when the SelectorMap was created) until a Region is found which contains the input position. The index associated with this Region is returned as the SelectorMap output value (the index value is the position of the Region within the list of Regions supplied when the SelectorMap was created, starting at 1 for the first Region). If an input position is not contained within any Region, a value of zero is returned by the forward transformation.
If a compound Mapping contains a SelectorMap in series with its own inverse, the combination of the two adjacent SelectorMaps will be replaced by a UnitMap when the compound Mapping is simplified using AST_SIMPLIFY.
In practice, SelectorMaps are often used in conjunction with SwitchMaps.
AST A Library for Handling World Coordinate Systems in Astronomy


text:
HP OpenVMS Systems Documentation
Guide to OpenVMS File Applications
6.4 DID-Abbreviated Directories (Alpha Only)
To support Extended File Specifications, RMS's user interface was extended to include capacities for the larger specifications that are sometimes necessary to access ODS-5-named files. (See the OpenVMS Record Management Services Reference Manual.) To take full advantage of all of the new features, applications would have to be updated to use the interface extensions. To provide extended capabilities (such as access to deep directories) to applications that continue to use the older interface, RMS supports the generation and acceptance of file specifications with an abbreviated form of root or directory specification, known as a DID (for Directory ID) abbreviation.
The DID is an alternate form of subdirectory specification that is not relative to the MFD. It takes the form (for ODS-2 and ODS-5 disks) of three decimal numbers separated by commas and can be used in the MFD position in a root or directory component specification.
Examples of valid root and directory components with DIDs are as follow:
A DID can also be used in place of a subdirectory in a root or directory component, but subdirectories located to its left in the specification (above it in the directory tree) are elided by RMS, as shown in the following example:
If a specification contains both a root with a DID and a directory with a DID, the root will be ignored (though not elided) by RMS.
The directory ID numbers are those that are displayed for a directory with the DIRECTORY/FILE_ID DCL command, as shown in the following:
When RMS attempts to generate a file specification that is too long for the application's output buffer, pointed to by the NAM block expanded or resultant string field, NAM$L_ESA or NAM$L_RSA; or by the NAML block short expanded or short resultant string file, NAML$L_ESA or NAML$L_RSA, it replaces the root and directory component with one that has the DID for the lowest level subdirectory of the replaced component(s). The specification that results can then be used as input to RMS.
It should be noted that not all RMS features are available with DIDs.
For example, attempts to use sticky defaulting with a root or directory
with a DID will result in an error. And you cannot create a directory
using a DID.
On Alpha systems, when a file specification, even with DID abbreviation, is too long to fit into a resultant name buffer (NAM block NAM$L_RSA field or NAML block NAML$L_RSA field), RMS attempts to generate a short-enough file specification by identifying the file with its file ID (three decimal numbers separated by commas, surrounded by brackets) in the file name component.
In cases in which the file type component would otherwise be presented, a generated file specification will either include the entire type or will not include any type (including the "." delimiter), depending upon whether or not there is space.
In cases in which the version component would otherwise be presented, a generated file specification will include the version component.
As a human-readable aid in recognizing files, when a FID is generated, the name component also contains a DCL-legal initial subset of the actual file name. The subset consists of the first 38 simple characters (where "^U1234" is six simple characters) of the actual file name, followed by "~".
No attempt is made to resolve ambiguities for files that differ only after the first 38 simple characters of their names.
An example of a generated name with a FID is as follows:
Such a file specification can be used as input to RMS, with some
A FID can be used for input to RMS, but only the FID is significant. The subset portion of the name component, the type component, and the version component are ignored by RMS.
As input, the FID-abbreviated file name component is not used as a default (as from a related file specification to replace a wildcard in an output specification). Instead, the output specification will get a null file name, as shown in the following:
Note that generated names with FIDs are possible only for resultant
specifications, which refer to specific files, and not for expanded
specifications, which do not necessarily refer to one file.
Process-permanent files are files that remain open independent of image activation and rundown. Process-permanent files are created by setting the process-permanent file bit (FAB$V_PPF) in the file-processing options field (FAB$L_FOP). When the bit is set, RMS-maintained internal data structures are allocated in the process control region of memory for the life of the process. Thus, process-permanent files can remain open across image activations. SYS$COMMAND, SYS$INPUT, SYS$OUTPUT, and SYS$ERROR are all opened in this manner by the LOGINOUT command image.
The DCL command OPEN also opens files in this manner. With user mode code, you can access process-permanent files only indirectly. RMS provides a subset of the total available operations to the indirect accessor.
Indirect accessors gain access to process-permanent files through the logical name mechanism, as follows:
|Function (Service)||FDL and RMS Options|
|Read records (Get)||ACCESS GET specified or FAB$B_FAC field FAB$V_GET set|
|Locate records (Find)||ACCESS GET specified or FAB$B_FAC field FAB$V_GET set|
|Delete records (Delete)||ACCESS DELETE specified or FAB$B_FAC field FAB$V_DEL set|
|Add new records (Put)||ACCESS PUT specified or FAB$B_FAC field FAB$V_PUT set|
|Truncate file (Truncate)||ACCESS TRUNCATE specified or FAB$B_FAC field FAB$V_TRN set|
|Modify records (Update)||ACCESS UPDATE specified or FAB$B_FAC field FAB$V_UPD set|
|Access blocks (see text)||ACCESS BLOCK_IO specified or FAB$B_FAC field FAB$V_BIO set; under certain conditions, ACCESS RECORD_IO or FAB$B_FAC FAB$V_BRO|
The record-access functions you request are compared with the protection on the specified file. If your process is limited to reading and locating records, it should have read access to the file. If your process is deleting, adding, truncating, or updating records, it must have write access to the file. RMS permits any process that may delete, add, truncate, or modify records to also locate and read records because write access to a file also implies read access.
You can perform block I/O operations using the Read, Space, and Write services. Block I/O is usually only used by applications written in VAX MACRO or other low-level languages. Note that when ACCESS BLOCK_IO is specified, the application program must also specify either SHARING USER_INTERLOCK or SHARING PROHIBIT.
Different types of record operations can be specified to define the type of access to be allowed for other processes, as shown in Table 7-2.
|Function (Service)||FDL and RMS Options|
|Read records (Get)||SHARING GET specified or FAB$B_SHR field FAB$V_SHRGET set|
|Locate records (Find)||SHARING GET specified or FAB$B_SHR field FAB$V_SHRGET set|
|Delete records (Delete)||SHARING DELETE specified or FAB$B_SHR field FAB$V_SHRDEL set|
|Add new records (Put)||SHARING PUT specified or FAB$B_SHR field FAB$V_SHRPUT set|
|Modify records (Update)||SHARING UPDATE specified or FAB$B_FAC field FAB$V_SHRUPD set|
|No access||SHARING PROHIBIT or FAB$B_SHR field FAB$V_NIL set|
|User interlocking||SHARING USER_INTERLOCK or FAB$B_SHR field FAB$V_UPI set|
|Multistreaming||SHARING MULTISTREAM or FAB$B_SHR field FAB$V_MSE set|
If other processes are limited to reading and locating records, they are unable to modify or add records, and record-lock checking is not performed. If other processes are allowed to delete, add, or modify records, they can also read records; however, record-lock checking occurs. All record-access functions use interlocked interprocess file sharing.
No access denies access to all accessors except the accessor who specifies the option. This option might be used when a file is shared infrequently or when doing a major update. When you use this option, be sure to close the file promptly when other users are trying to access the file. Choose this option or the user-interlocking option when using block access. To use the Queue I/O Request system service, specify the FILE USER_FILE_OPEN attribute (FAB$L_FOP field FAB$V_UFO set). The no-access option does not allow file sharing and requires that your process have write file protection access.
User interlocking permits the user to maintain interlocking protection (including maintaining the end-of-file mark). For any other form of file sharing, RMS controls the reading and writing of I/O buffers to ensure the integrity of file and record structures. This option is useful for nonshared sequential files and for block I/O access using RMS or the Queue I/O Request system service.
Multistreaming allows your process to access the same file using more than one record stream and allows other users to access the file using interlocked interprocess file sharing (unless SHARING PROHIBIT is also


Take the 2-minute tour ×
Is there any way to get the total page count after selecting multiple word documents in a folder?
share|improve this question
3 Answers 3
Hopefully this will enlighten you a little further than the rather brief answer provided by another user.
Simple answer: no.
Detailed answer: A MS Word document only has "pages" once it is generated (i.e. opened). The main reason for this is to do with the page size. For example: if you have three documents under scrutiny, formatted to sizes A5, A4 & A3 respectively, then to count the number of pages collectively would be practically impossible to display in a simple, logical / coherent format.
The only potential way around this is to write some custom software which opens each desired document one after the other, logs the page sizes of each respective document, and then counts the number of pages within each page size category and logs it before closing each document and proceeding to the next.
Hopefully this will be of help to you.
Many thanks.
Adam's response (Nov 22 '12 at 15:08) is also somewhat correct and I feel that I should elaborate on my answer; Word does store a page count for some document types, but not all, as Adam quite rightly states. I chose to treat this factor as an 'all or nothing' property; either it stores a page count for all document types, or none at all. Hence why if you extract the page count property from each document, it may result in incorrect / inaccurate data due to particular file types not being read. This is why my suggestion of custom software would be the best overall option as the data can become stale or inaccurate and not always reflect the facts. This is why it is better to consider Word as not storing any page number properties rather than just some.
I hope this also helps?
share|improve this answer
Thanks for the info. I don't suppose you have a link to any such custom software? – Paul Spangle Nov 20 '12 at 11:57
I'm afraid not; however, the logic behind the software should not be too difficult to implement. The software is required to look in a directory, locate all.doc /.docx files and then from there, open the document, log the number of pages (if you wish to include page size here, it will require more detailed analysis of the document), add the total to a running count for each page size, then close the document and move onto the next until all have been analysed. – SnookerFan Nov 20 '12 at 15:09
_USER_ please don't harass users to accept an answer, and please don't abuse flags to ask moderators to do so on your behalf. The choice to select an answer is entirely the user's; if they don't want to select an answer, they don't have to. I'm sure it's no coincidence that your sudden and intense interest in this user marking their solution is not coincidental. Don't worry about 15 points - just acknowledge that sometimes people don't mark an accepted answer, and your time is better spent writing new answers than begging for a checkmark on an answer from a year ago. – nhinkle Oct 21 '13 at 8:46
Not coincidental in relation to what, exactly? – SnookerFan Oct 21 '13 at 10:12
Has this worked? – SnookerFan Nov 22 '13 at 10:16
This same question came up at work and Google brought me here. There isn't a way to select the documents in Windows Explorer and obtain a page count, but there are other methods that might provide a good enough estimate.
I'm thinking of trying out this PowerShell script: Hey, Scripting Guy! How Do I Count the Number of Pages in a Group of Office Word Documents? For an end user I would set up a shortcut and maybe prompt for the folder location.
share|improve this answer
SnookerFan's detailed answer is a little off, Microsoft Word does store the number of pages in a document as a document property when the document is saved. This value is what shows up in the explorer when you view the properties of the file and it should be correct 99% of the time although I'm sure there are some situations where the value of this property could become stale and incorrect.
Therefore you could create a simple application and even make it into a shell plugin to query this property and add the values together.
One thing to keep in mind is this property is displayed for DOC and DOCX documents but isn't for RTF format even though it is written to the RTF document (represented by the {\nofpagesX} keyword).
share|improve this answer
Your Answer


text:
Eric Warrant and Gerhard von der Emde, "The Ecology of Animal Senses: Matched Filters for Economical Sensing"
English | ISBN: _PHONE_ | 2016 | 269 pages | PDF | 8 MB
The collection of chapters in this book present the concept of matched filters: response characteristics "matching" the characteristics of crucially important sensory inputs, which allows detection of vital sensory stimuli while sensory inputs not necessary for the survival of the animal tend to be filtered out, or sacrificed. The individual contributions discuss that the evolution of sensing systems resulted from the necessity to achieve the most efficient sensing of vital information at the lowest possible energetic cost. Matched filters are found in all senses including vision, hearing, olfaction, mechanoreception, electroreception and infrared sensing and different cases will be referred to in detail.


text:
To create a query in Access 2013 or 2016:
- Click the CREATE > Query Design button on the Ribbon.
- Choose the tables to include in the query
- Choose the fields to include, and adjust the criteria
- Click the Run button (or just switch to Datasheet view)
The results of the query will be displayed.
You also have the option of saving your query. To save the query, right-click on the query tab. click Save, and name it at the prompt.
To create a relationship in Access 2013 or 2016:
- While viewing a table in Design view, and ensuring that the DESIGN tab is selected, click Relationships from the Ribbon
- A Show Table dialog will appear with a list of tables and queries. Select the tables (and/or queries) that you wish to create a relationship between, and close the dialog
- The Relationships tab will appear with the selected tables. Click and drag a field on top of a field in another table to initiate a relationship.
- The Edit Relationships dialog will pop up containing both fields. Make any adjustments and click OK
This will create the relationship. You will see the tables in the Relationship tab with lines depicting the relationship between the tables.
To add a macro to a form in Access 2013 or 2016:
- Create a macro
- Now, open the form in Design view
- Click the Button icon in the Ribbon (from the DESIGN tab)
- In the Form Detail area, click and drag the cursor so that it forms a square or rectangle (i.e. shape of a button). The Command Button Wizard will pop up. Select Miscellaneous > Run Macro and click Next
- Select the name of the macro you want to run and click Next
- Choose whether to display text or an image on the button and click Next
- Give the button a name and click Finish
To export from Access 2013 or 2016 to Excel:
- Open the table or query that contains the data you want to export
- Click the Excel download icon (from the EXTERNAL DATA tab on the Ribbon)
- Click OK to save the file at the default location. Alternatively, change the location and/or a file name. Select any other options you wish to include under Specify export options
- Click Close
To create a macro in Microsoft Access 2013 or 2016:
- Click Macro from the CREATE tab
- Add actions by selecting an action from the combo box
- Customise the actions if required
- Repeat steps 2 and 3 for each action you want to add
- Save the macro
To create a table in Microsoft Access 2013 or 2016:
- Click CREATE from the Ribbon
- Click Table
Here's what that button looks like on the Ribbon:
Clicking the "Table" icon from the "CREATE" tab creates a new table.
Those two steps create a blank table.
Once you've created your table, you will need to add fields (these will contain the data). You will also need to specify the type of data that the fields will contain (eg, text, number, date, etc).
You can also add extra rules about the type of data that can be entered into each field (eg, that phone numbers should be entered this way, dates should be entered that way, etc), as well as other properties for each field.
In Microsoft Access 2013 & 2016, you can create a database straight from the Welcome screen or from the work area. You can create either a blank database, or a database from a template.
Create a Blank Database
From the Welcome Screen
When you first open Access, the Welcome screen is displayed. You can create your database straight from here.
- Click Blank desktop database
- Name the database at the prompt and click Create
Your new database will have one table called "Table1". You can modify this table to your needs. You can also create new tables and other database objects.


text: Editor's note: This is the fifth column in a series that challenges misconceptions about entrepreneurship. Myth: When measuring share of small business employment, the terms "small firm" and "small establishment" mean the same thing. Reality: To determine the share of employment small businesses account for in the U.S., I've always used data from the Office of Advocacy of the Small Business Administration which provides data produced by the U.S. Census on small business employment. The Census data on the SBA Web site shows that, in 2006 (the latest year available), 50.2% of U.S. employment lies in businesses with fewer than 500 employees. But recently I began looking at data from payroll provider Automatic Data Processing (ADP), which uses payroll data to track U.S. employment. ADP's data shows that the share of U.S. employment in businesses with less than 500 employees is more than 30 percentage points higher. In 2006, the ADP data showed that 82.9% of U.S. employment was in businesses with less than 500 employees. Huh? A 32.7% gap in the share of employment in businesses with fewer than 500 employees is much too large to be the result of just some slight difference in measurement. So something else must be going on. What's Behind the NumbersTo figure out what could explain the differences, I took a look at what the two sources are measuring. Both are comparing employment in businesses of less than 500 employees to the overall number of people employed and both exclude employment on farms. So it's not the size of the businesses or the exclusion of agriculture that's the cause of the difference. It's also not their labor force figures. The two sources' estimates of the number of people employed aren't that far off each other—119,917,000 for the SBA in 2006 and 113,475,000 for ADP in 2006. Even if we assume that every employee counted by the SBA and missed by ADP was employed in a large business, ADP's estimates would show that small businesses accounted for 77.2% of U.S. employment, whereas the Census/SBA estimates would show that small businesses only accounted for 50.2% of U.S. employment. The use of payroll data is also not the explanation. Census measures employment on the basis of payroll tax records, using employer identification numbers to identify businesses. ADP gets its estimates from "aggregated and anonymous payroll data that represents approximately 400,000 of ADP's 500,000 U.S. business clients" which are then extrapolated to the overall population. So both sources are using payroll data to measure employment. Different definitions of "business"The difference, it turns out, lies in how the two groups define "businesses." ADP is measuring establishments, whereas Census is measuring firms. And small establishments, it turns out, are very different than small firms. According to the U.S. Census, "an establishment is a single physical location where business transactions take place and for which payroll and employment records are kept." Firms are "groups of one or more establishments under common ownership or control." Many more Americans work in establishments with fewer than 500 employees than in firms with fewer than 500 employees because a lot of establishments are part of large firms. For example, the Gap (GPS) outlet at your local mall is considered an establishment if it has fewer than 500 employees, but it is considered part of a firm if it has more than 500 employees. So if we measure employment at establishments with fewer than 500 employees, everyone working at the Gap outlets in different malls around the country would be considered employed in small establishments. However, if we measure employment at firms with fewer than 500 employees, everyone working at those different Gap outlets (as long as they weren't franchised) would be considered employed at large firms. The difference between the establishment and firm data is corroborated by looking at County Business Patterns, a Census Bureau effort to measure establishments. County Business Patterns shows small establishment employment numbers very similar to those shown by ADP. In 2007, the Census data shows 79.7% of employment was in establishments with fewer than 500 employees, while ADP shows that 83.1% of employment was in "businesses" with fewer than 500 employees. Skewed Employment StatisticsPutting the data together, it is clear that a lot of people work in small establishments that are part of large firms. Unfortunately, most people looking at the different sources of data don't know this, especially since the different sources are saying that they are measuring "businesses." And, unless people look at both sources at the same time, they probably don't even know they are different. But the difference does make it difficult to discuss a basic fact about small business—the share of employment it accounts for. There are probably a number of reasons why measuring small establishments is problematic when seeking to understand small businesses. But here's just one: suppose policymakers want to put in place policies to increase small business employment if small business isn't accounting for an increasing share of total employment. If policymakers look at establishment data, they will get the wrong answer about what to do. The share of employment in small firms has been constant in recent years, while the share of employment in small establishments has been rising. So looking at establishment numbers would give policymakers the impression that small business is accounting for an increasing share of employment. A fact that turns out to be untrue.


text:
Better performance of slag concrete exposing to high temperatures
Concrete made with GGBS cement is much better than concrete made with 100% OPC at maintaining its compressive strength when exposed to high temperatures.
OPC specimens heated to 400 °C or above have been shown to exhibit severe cracking to the point of disintegration after a few days. However, it was found that concrete made with blends of 35%, 50% and 65% GGBS performed much better. In the GGBS specimens there was no visible cracking after exposure to the higher temperatures. The concrete with 100% OPC degraded to powder over the following year, while the concrete made with GGBS maintained its strength over the same period.
Further studies showed that after exposure to 900 °C concrete with 0% GGBS maintained 6% of its original strength, concrete with 30% GGBS maintained 54% of its original strength and concrete with 70% GGBS maintained 70% of its original strength.
How does slag improve the resistance to fire damage?
Why concrete made with GGBS has better resistance to fire damage? It is generally agreed that above 400 °C Ca(OH)2 which is the hydration products of OPC decomposes into CaO and H2O, then on cooling CaO and left H2O rehydrates into Ca(OH)2 which needs more space than CaO causing the concrete to crack and degrade. With the addition of GGBS into concrete, hydration product Ca(OH)2 is generally reduced compared with concrete made with 100% OPC, thus improving the performance of resisting fire damage.
Reference: Ecocem report–Technical Performance
- Sample Preparation for Quantitative X-Ray Diffraction (XRD/Rietveld)
- Determining the Amount of Reacted Slag in Blended Cement Using EDTA Method
- 3D printer to print a house, is it the future of cementitious materials?
- How GGBS is used and its typical substitution rates
- Does particle size of slag influence its reactivity?
- Published literature data on the reaction degree of slag
- Methods to measure the reaction degree of slag in blended cement
- Factors influence the reaction degree of slag in slag blended cement
- The activation theory of slag in blended cement
- Features of microstructure development in the inner product of reacting slag in blended cement


10 Tiny Countries With Enormous Natural Beauty
Clear, turquoise water laps against a palm tree-covered island in the Maldives
With nearly 200 countries on Earth, the public imagination often confines our planet's awe-inspiring formations and wildlife to those wonders located within the borders of large and powerful nations. Immense natural beauty, however, can be found in some of the world's smallest countries. Whether one looks to the delicate coral reefs of the Maldives or the steep, cragged mountains of Liechtenstein, breathtaking vistas can be found in the most unlikely of places.
Here are 10 tiny countries, from Andorra to Niue, with enormous natural beauty and wonder.
of 10
The rocky, grassy slope of a mountain with a road stretching into the background of snow-capped mountains
Faer Out / Shutterstock
The Kingdom of Lesotho, a landlocked country slightly smaller than the state of Maryland and enveloped completely by South Africa, boasts a dramatic mountainous landscape of immense appeal. Sometimes referred to as the kingdom of the sky, Lesotho sits entirely above 1,400 meters (4,593 feet). The country's peak, the summit of the mountain Thabana Ntlenyan, reaches 3,481 meters (11,423 feet) in elevation. Lesotho also lays claim to the spectacular 211-meter (692-foot) waterfall Maletsunyane Falls.
of 10
A boardwalk staircase ascends into the canopy of a tropical rainforest in Brunei
Ngotoh / Flickr / CC BY-ND 2.0
A small Southeast Asian country, 5,765 square kilometers (3,582 square miles), located on the northern coast of the island of Borneo, Brunei has increasingly become a destination for ecotourism. Ulu Temburong National Park features vast tropical rainforests that stretch from the hilly lowlands up toward peaks like that of the country's highest point, Bukit Pagon. Small stilt-house river villages that sit directly over the water are a common sight, even near the modern capital of Bandar Seri Begawan.
of 10
Lush green fields in the foreground give way to small valley of quaint buildings and a towering mountain in the background
Boris Stroujko / Shutterstock
The Principality of Liechtenstein is a small German-speaking nation that appears on the map as a small dot between Austria and Switzerland and is only about one-tenth the size of Washington D.C. Known for its beautiful mountain scenery and quaint alpine villages, the country draws a large number of tourists throughout the year. Liechtenstein is home to medieval fortresses like the stunning Gutenberg Castle and breathtaking views like those found on Drei Schwestern mountain, or The Three Sisters Mountain.
of 10
A sunbeam casts light upon an autumnal wooded scene in Mullerthal, Luxembourg
Tristan Schmurr / Flickr / CC BY 2.0
Another European kingdom, Luxembourg, sits between France, Germany, and Belgium, and is relatively large in size, 2,856 square kilometers (1,606 square miles), making it one of the larger nations on this list. Luxembourg's Mullerthal region, or Little Switzerland as it is often called, offers picturesque country landscapes of rolling hills, wooded highlands, and towering rock formations, and is perhaps best experienced by hiking trail. The northern region of Éislek, or Ardennes, showcases the country's sweeping valleys and majestic forests, dotted with the historic remains of medieval castles.
of 10
Blue skies with a few clouds hover above snow-capped mountains on the horizon
Leon G / Flickr / CC BY 2.0
Andorra, a principality of more than 85,000 people and covering 468 square kilometers (290 square miles), is nestled in the Pyrenees mountains between Spain and France. In the southeastern region, the Madriu-Perafita-Claror Valley offers exceptional glacial vistas and is as noteworthy for its cultural importance as it is for its captivating beauty. The higher reaches of the valley are composed of cliffs and exposed rock glaciers that slope down to woodlands and a gorge below. The Madriu-Perafita-Claror Valley was deemed a World Heritage Site in 2006 for its microcosmic display of Pyrenees mountain culture over the millennia.
of 10
The sun sets of a beach with silhouetted palm trees in the Maldives
Giuseppe Milo / Flickr / CC BY 2.0
Dispersed along the Arabian Sea in the Indian Ocean is the breathtaking nation Maldives, consisting of islands combined into a chain of 26 atolls, or ring-shaped coral reefs. The country has a combined landmass of about 298 square kilometers (185 square miles) and its islands span a distance of 871 kilometers (541 miles). The highly protected Baa Atoll Biosphere Reserve is brimming with wildlife, like manta rays, marine turtles, and the endangered tawny nurse shark, which are part of a diverse and delicate interplay between coral reef systems and the many species that live there.
of 10
A large rock formation rises above a lush valley of green in Eswatini
mbrand85 / Shutterstock
Gorgeous landscapes and impressive wildlife are at the forefront of the tourism industry in the Kingdom of Eswatini (formerly Swaziland as of April 2018), which rests on the border between South Africa and Mozambique. Vast tracts of protected land, like Hlane Royal National Park, Mlawula Nature Reserve, and Malolotja Nature Reserve, exhibit white rhinos, lions, zebras, and elephants, among other animals native to the region. The Kingdom of Eswatini is also a birdwatcher's paradise, with nearly 500 species of birds recorded within the country, including the national bird, the purple-crested turaco.
of 10
An arched rock formation extends over clear, tropical waters
vuorikari / Flickr / CC BY-SA 2.0
Niue, a remote tropical island in the South Pacific, is known for its elaborate cave systems, magnificent arches, and its beautiful clear waters. A small country, roughly 260 square kilometers (161 square miles), Niue features remarkable limestone cliffs that soar above the water's surface to form the island's central plateau. The magnificent Humpback whale migration comes to Niue annually from July to October, as mothers seek a safe location to feed their calves.
of 10
A lush green hill in the foreground with hills stretching back into the horizon
Chris Favero / Flickr / CC BY-SA 2.0
North of Trinidad and Tobago, between the Caribbean Sea and the Atlantic Ocean, lies the small island of Grenada. The tiny nation, just 344 square kilometers (213 square miles), is home to the dormant volcano Mount Saint Catherine, whose peak is the highest point on the island at 840 meters high (2,775 feet), and an active volcano called Kick 'em Jenny that lies off the coast on the ocean floor. Grenada also lays claim to extensive nature preserves like the Grand Etang and Annandale Forest Reserves.
of 10
San Marino
A castle sits atop a cliff looking over a vast valley town below in San Marino
Leonid Andronov / Shutterstock
San Marino, an enclave of central Italy about one-third the size of Washington D.C., features a rugged mountainous landscape of breathtaking beauty and wonder. The third smallest country in Europe, San Marino is home to the visually striking Monte Titano, or Mount Titan, which lies just southeast of the capital city of San Marino. The three towering peaks of Monte Titano house centuries-old fortresses and other notable structures, including a 19th century basilica, and the illustrious locale has been honored with the demarcation as a World Heritage Site.


text:
Utilisation of waste material for environmental applications: calcination of mussel shells for waste water treatment
Jones, M. I., Wang, L. Y., Abeynaike, A. and Patterson, D. A., 2011. Utilisation of waste material for environmental applications: calcination of mussel shells for waste water treatment. Advances in Applied Ceramics, 110 (5), pp. 280-286.
Related documents:This repository does not currently have the full-text of this item.
You may be able to access a copy if URLs are provided below. (Contact Author)
Waste mussel shells from the New Zealand aquaculture industry have been investigated as a potential source of lime for use in waste water treatment. The calcination of raw mussel shells to lime was studied as a function of particle size, temperature, heating rate, treatment time and atmosphere. Lime formation went through a maximum with respect to particle size for all heating conditions, as a result of competition between increased surface area and a tendency for particle to form necks resulting in caking. Optimised heat treatment conditions resulted in transformations of more than 95%. Preliminary experiments to investigate removal of phosphates from model waste water solutions showed that raw shells had limited ability due to a mechanism that relies on adsorption only. For these raw materials the finer particle sizes removed more phosphate due to increased surface area. The heat treated mussel shells on the other hand were shown to remove greater than 95% of the phosphates for both fine and coarse size ranges due to a precipitation mechanism of phosphate removal. This work demonstrates the potential for using mussels as an alternative to limestone for phosphate removal, at the same time overcoming the expensive and problematic issues of waste disposal.
|Creators||Jones, M. I., Wang, L. Y., Abeynaike, A. and Patterson, D. A.|
|Departments||Faculty of Engineering & Design > Chemical Engineering|
Actions (login required)


Take the 2-minute tour ×
This XML file is named example.xml:
 Environment for UberPortalConf
 This is the description

If I load the example.xml file above using ElementTree and print the root node:
>>> from xml.etree import ElementTree
>>> tree = ElementTree.parse('example.xml')
>>> print tree.getroot()
I see that Element also contains the namespace _URL_
How do I:
 1. Get the foobarportal.version text, increase it by one and write the XML file back while keeping the namespace the document had when loaded and also not change the overall XML layout.
 2. Get it to load using any namespace, not just _URL_ I still don't want to strip the namespace, as I want the XML to stay the same except for changing foobarportal.version as in 1 above.
The current way is not aware of XML but fulfills 1 and 2 above:
 1. Grep for (.*)
 2. Take the contents of the match group and i increase it by one
 3. Write it back.
It would be nice to have an XML aware solution, as it would be more robust. The XML namespace handling of ElementTree is making it more complicated.
share|improve this question
I've tried tree.getroot().find('project') which does not work due to the namespace. After that I am pretty much stuck and the documentation didn't help me. – Deleted Feb 29 '12 at 15:26
Show us the code you have tried, in the question. – Marcin Feb 29 '12 at 15:43
add comment
1 Answer
If your question is simply: "how do I search by a namespaced element name", then the answer is that lxml understands {namespace} syntax, so you can do:
share|improve this answer
add comment
Your Answer


text:
2017-2018 Elective Courses
- Advanced Band
- Intermediate Band
- Jazz Band
- Spanish (yearlong)
- STEM (yearlong and trimester long)
Theatre Production 7 is a year long elective class. Students will participate in a play and a musical. The musical will require some after school rehearsal time, usually in March and April. Students interested in joining this class must contact Mrs. Anderson at _EMAIL_ for an audition.
Theatre Production 8 is a year long elective class. Students will participate in two plays and a musical. The musical will require some after school rehearsal time, usually in January and February. Students interested in joining this class must contact Mrs. Anderson for an audition.
Intro to Principles of Design, Elements of Art
and CTE Standards
1. Intro to DMA AND CTE procedures, Standards, basic drawing, digital photo, graphic design and iPad Apps.
2. Intro to Digital Photo and Adobe Workshop.
3. Intro to Principles of Graphic Design.
- Create a Google Doodle style drawing for weekly vocab word. Compete in "Doodle for Google" contest (volunteer basis).
- Learn the Rule of Thirds and the Golden Spiral for compositions. Learn how to take good photos. Learn how to take individual and group shots. Edit in Adobe.
- Create Photo album/portfolio for digital photo projects to use in Adobe
- Explore all Adobe iOS Apps and create a project using each.
- Intro to Graphic Design. Create a project from idea to concept, draw it, photoshop it, crowd source funding for production, write and film a commercial to advertise your product.
- 5. Video Production - Intro to the making a short video, sound, special effects. plot, camera angles, rule of thirds and music in Garage Band.
- Students will work on individual projects and in groups of two when learning new Apps and larger groups when needed for filming.


text:
Line Graphs and Parallel Processing in R
A few months ago I came across one of the most beautiful visualizations I have ever seen: James Cheshire's Population Lines Print. What I love about it is that, in the absence of any traditional map features, the outlines of countries and continents are immediately apparent. And as long as you are familiar with what the land masses of the globe look like, you know exactly what the plot is without even needing to be told. Another interesting feature is that the peaks also give information about both the population and and the density: the area under the graph represents the total population, while the higher the peak, the more dense it is. (Hence the huge peak of Tokyo, and the low, wide peak of Mexico City.)
When I first saw the post, I went to this blog to see how he pulled it off. Unfortunately, there weren't any details. So, I had to figure it out myself.
Well, I think I got it! I'll show you a few of the plots first, and then describe the process below.
Using the same NASA SEDAC data that James used, here is the plot, produced entirely using R (click for higher resolution):
And, for my fellow New Brunswickers, here's the same dataset of NB properties I plotted a while ago, plotted again using a line graph:
And finally, here is the property value data from my last post for Fredericton. Note that, as mentioned above, unless you're familiar with the geography of the area, it may not be directly apparent what you're looking at here. For those that are, you can immediately spot the river flowing through the middle of town with the tributaries flowing in:
These maps aren't the most practical ways of plotting data into a third dimension since you can't really 'dive deeper' into them to get more detail, but they are certainly one of the most beautiful I've seen.
So, how was it done?
EDIT: I've updated the below instructions since this was originally published to provide an alternative to using QGIS (thanks _USER_ for pointing out I could do this in R itself). I also improved the performance about 3x by replacing my data frames with data tables.
Well, like everything else I do on here, I wanted to accomplish this using only freely available software. In this case, I used a combination of R, QGIS and Libre Office (the latter two being optional). The work was divided into three main pieces:
- Extract the data from NASA's data set.
- Crunch the data to prepare it for plotting.
- Actually do the plotting.
All the code for processing and plotting is available here: GeospatialLineGraphs.
Extracting the Data
James originally used NASA's population density data from the year 2000. Though the outcome should be the same, I decided to use the raw population data available here. On that page, go to download, select the format as ".ascii", the resolution as 1/2°, and the year as 2000.
Once you've downloaded it, you can do either of the following to get the data into a workable form:
- Put the file glp00ag30.asc into a folder called DataSets in your working directory
- Run this part of the R script which uses the 'raster' package to turn it into a set of points. The rest of the script is described in the next section.
- Import the data into QGIS
- Go to Raster > Conversion > Polygonize (Raster to Vector), and check the "Add to map" box
- Select that layer, and go to Vector > Geometry Tools > Polygon Centroids and follow the menu items, making sure to check "Add result to canvas". This will generate another layer with point data from your polygon data.
- Right click the points layer, and save it as a CSV file. It should automatically export the X & Y coordinates.
- Finally, load the data with this part of the script and make sure to comment out the part above that uses the 'raster' function mentioned above.
There, you data is ready to be crunched.
Processing the Data to be Plotted
Next, you have to take this data and turn it into something that can be plotted. The code to do this is available here: Geospatial Line Graphs - Generate Data.
The basic idea behind what this does is this:
- First, find the boundaries of the plot to know the start and end latitude and longitudes you want to plot over.
- Using the start and end latitudes, create 200 evenly spaces points of latitude - one for each line that will be plotted.
- For each point of latitude, draw a square with sides equal to the gaps between the points of latitude. Calculate the total of whatever data you're interested in inside that square.
- Move the square over an amount of longitude equal to the width of the square, and repeat the above calculation.
- Do this until you've calculated everything, and output it all to a CSV file.
Now, when you're dealing with 500,000+ pieces of data, this can take a while if you're not taking advantage of your hardware's capabilities. In the case of the NB data, it originally took 2 hours to crunch on my 2.3 GHz i7, which has 4 cores (8 virtual), but only one was being used.
Luckily, R now has the ability to do parallel processing to take full advantage of multi-core CPUs. Marcus over at R-bloggers has a great tutorial on how to do this in R if you want to have a look. Furthermore, using data tables instead of data frames can also improve performance by, in my experience, about a factor of 3 for this computation. Using both of these together got the time to process from 2 hours to about 2 minutes for both the NB and world population data set.
Plotting the Data
To plot the data, I wrote this script which does the following:
- Load the data you want to plot, and pad the top and bottom to give it a border (padding the left and right is most easily done in a spreadsheet by adding rows of 0's to the top and bottom).
- Find the maximum value in all of the data, and select a factor that will be used to scale the line heights to fit the plot (this is done through trial and error).
- Starting at the top, grab a row's data, smooth it with a spline, and plot a white polygon at the appropriate height.
- Outline the top of the polygon with a gray line.
- Plot black line segments over the gray line if the values are over a certain threshold.
- Repeat for the rest of the rows, moving down the plot area as you go so that the lower polygons overlap the upper ones.
There you have it - that's all there is to these beautiful line plots. If you love the world map, go buy it from James here to support the work he does: Population Lines. And as always, if you have any questions, ask away below or send me an e-mail.
Like this? Then tweet it! Oh, and follow me too.


text:
The key performance measures evaluating the BFI's contribution to the further economic and cultural success of film.
The BFI will capture and disseminate, through the work of the BFI Research & Statistics Unit, a wide range of qualitative and quantitative information about film in the UK which, taken together, will track the performance of UK film and provide important information for the whole of the film sector.
For the BFI, we aim to measure our contribution to the further economic and cultural success of film through our strategy for which there are 13 key performance measures which can be tracked through the life of this strategy online at bfi.org.uk.
By 2022 we will have:
- Increased the diversity of audiences and talent supported across all BFI activities
- Increased engagement with BFI activities across the UK and increased the quality and cultural depth of their experience
- Increased participation of 16-30 year olds across all BFI activities and funded programmes
- Increased access to the BFI's National Film Archive and those of the regions and Nations
- Further conserved and digitised the most at-risk materials within the BFI National Film Archive, notably video and television
- Ensured the opportunity to learn about the art of film in school
- Improved employers' ability to recruit a skilled workforce across the UK
- Supported talent to progress in their filmmaking careers
- Funded a range of innovative and pioneering moving image work intended for a variety of platforms
- Supported British films and British talent which have received recognition domestically and internationally
- Invested in start-up film businesses outside of London which have leveraged additional investment and increased levels of employment
- Supported a greater geographic spread of inward investment production in the UK
- Supported an economic and cultural environment that keeps the UK film industry internationally competitive


Take the 2-minute tour ×
Does there exist a prime 3-manifold such that its mapping class group has an abelian representation in which the 2$\pi$ rotation is represented by -1?
In detail: Let $M$ be a closed orientable prime 3-manifold. Let $D_F(M,p)$ be the group of diffeomorphisms of $M$ that fix a point $p$ of $M$ and a frame there. Define the mapping class group (MCG) of $M$ to be the zeroth homotopy group of $D_F(M,p)$. Then the $2\pi$ rotation is an element of MCG that is the equivalence class of the following diffeo, $R_{2\pi}$: Consider a coordinate ball of radius 2, $B2$, centred on $p$. $R_{2\pi}$ fixes the ball of radius 1, $B_1$, centred on $p$ and everything outside the sphere of radius 2. In between $B_1$ and $B_2$ the $R_{2\pi}$ maps $(x,y,z)\rightarrow(x\cos\theta+y\sin\theta,y\cos\theta−x\sin\theta,z)$ where $\theta$ is a function of $r=\sqrt(x^2+y^2+z^2)$ which increases smoothly and monotonically from 0 to 2$\pi$ as $r$ increases from 1 to 2. The square of the 2$\pi$ rotation is the identity in MCG. A manifold is spinorial if $\[R_{2\pi}\]$ is non-trivial in MCG.
Background motivation:
This question is interesting because of the possibility that fermions can be built on non-trivial spatial topology. $M$ is the manifold of a 3-D spatial hypersurface in spacetime. The fixed point is the point at infinity (where the metric is asymptotically flat) and fixing a frame there has the same effect on $\pi_0(D_F)$ as requiring some falloff conditions on the diffeomorphisms at infinity or requiring them to be the identity outside some ball. The configuration space of General Relativity in this asymptotically flat setting is (space of asymptotically flat metrics on $M$)/$D_F$ and its first homotopy group is isomorphic to (what I called above) MCG, see _URL_ (I know it is not the usual definition of MCG). The quantum state, on canonical quantisation of General Relativity, carries a unitary irreducible representation (UIR) of the MCG and different choices of UIR give different physics. Prime 3-manifolds are potentially candidates for elementary particles built from pure geometry: topological geons (this is speculative!). A prime 3-manifold can be the basis for a spinorial particle (i.e. spin 1/2, spin 3/2....) if $R_{2\pi}$ is nontrivial. Because particles must be able to be pair produced and annihilated, topology change must be allowed in the theory which means that the theory should be quantised in a sum-over-histories framework rather than a canonical quantisation framework. Within the sum-over-histories framework it is challenging to realise nonabelian reps of MCG. Abelian reps on the other hand are more easily accommodated by attaching phases to topologically distinct sectors of the path integral. Moreover certain rules that would result in a spin-statistics correlation for topological geons would also force the reps to be abelian, _URL_ (hence the need for abelian reps). However, if there were no spinorial primes with abelian reps this would rule out spinorial geons and therefore fermions.
share|improve this question
What do you mean by 'the' $2\pi$ rotation? – HJRW May 16 '11 at 12:21
Please edit the question statement to put in the clarifications. You're also presumably assuming that the manifold is spin, and looking at the spin mapping class group. – Dylan Thurston May 16 '11 at 13:25
1. This is not the usual definition of MCG. 2. By the belt trick, the $2\pi$ rotation squares to be the identity. 3. The $2\pi$ rotation is central. 4. I don't know what you mean when you say "abelian representation" or "represented by -1". – Sam Nead May 16 '11 at 13:28
Even with the edit, "represented by -1" is not clear. Are you asking for this element of the mapping class group to map onto the generator of an infinite cyclic group? That's how I read your question. – Ryan Budney May 16 '11 at 19:33
1 Answer 1
up vote 8 down vote accepted
Yes, there exists such a manifold $M$. This follows if there exists aspherical $M$ with $Diff(M)\simeq 0$ (contractible) and $H^2(M;\mathbb{Z}/2\mathbb{Z})=0$. I claim there exists such manifolds. Let's see why such $M$ suffice.
There are two fibrations: $$ D_F(M,p) \to Diff(M,p) \to GL(3,\mathbb{R})$$ and $$ Diff(M,p) \to Diff(M) \to M.$$
The first comes from considering the derivative at $p$ of a diffeomorphism fixing $p$. The second comes from considering the image of $p$ under a diffeomorphism of $M$.
From the long exact sequence of homotopy for a fibration (e.g. 4.41 Hatcher), we have the exact sequence $$0=\pi_2(M) \to \pi_1(Diff(M,p)) \to \pi_1(Diff(M))=0 \to \pi_1(M)\to $$ $$\pi_0(Diff(M,p))\to \pi_0(Diff(M))=0.$$ We see that $\pi_0(Diff(M,p))=\pi_1(M)$, and $\pi_1(Diff(M,p))=0$. Similarly, $$0=\pi_1(Diff(M,p))\to \mathbb{Z}/2\mathbb{Z}=\pi_1(GL(3,\mathbb{R})) \to \pi_0(D_F(M,p))\to \pi_0(Diff(M,p))\to 0.$$
From the second sequence, we see that $\pi_0(D_F(M,p))$ is therefore a $\mathbb{Z}/2\mathbb{Z}$ extension of $\pi_1(M)$. These are classified by $H^2(\pi_1(M);\mathbb{Z}/2\mathbb{Z})=H^2(M;\mathbb{Z}/2\mathbb{Z})=0$ (since any such extension is central). Thus, it is a trivial extension, so $\pi_0(D_F(M,p))=\mathbb{Z}/2\mathbb{Z}\times \pi_1(M)$. The $\mathbb{Z}/2\mathbb{Z}$ factor is generated by $[R_{2\pi}]$ in your notation, so clearly the desired abelian representation exists.
Now we need to see that a closed orientable aspherical manifold $M$ with $Diff(M)\simeq 0$ and $H^2(M;\mathbb{Z}/2)=0$ exists. In fact, we may assume $M$ is a hyperbolic homology sphere. For example, take a hyperbolic knot complement with trivial isometry group. Perform Dehn filling of slope $1/k$ for $k$ large to get a closed hyperbolic manifold. This manifold will be an aspherical homology sphere and will have trivial isometry group for $k>>0$ (this follows from Thurston's Dehn surgery theorem and the Margulis lemma, since the isometries must preserve the short core geodesic of the Dehn surgery). By a result of Gabai, $Diff(M)$ will be contractible.
One can work in somewhat greater generality with hyperbolic 3-manifolds $M$ which have the property that $H^2(Aut(\pi_1(M));\mathbb{Z}/2\mathbb{Z})=0$, since the first exact sequence implies that $\pi_0(Diff(M,p))=Aut(\pi_1(M))$. I'm not sure what happens if $H^2(Aut(\pi_1(M));\mathbb{Z}/2\mathbb{Z})\neq 0$; I assumed it $=0$ as a convenient way to see that the group $\pi_0(D_F(M,p))$ splits.
share|improve this answer
Thank you for your answer. I'm still reading through it to try and understand it all but it looks like it's what I'm looking for. Do you mean that $\pi_0(D_F(M,p))$ (as opposed to $\pi_0(Diff(M,p))$) is a $\mathbb{Z}/2\


Take the 2-minute tour ×
Is there an easy way to create and Object and set properties in C# like you can in Javascript.
Example Javascript:
var obj = new Object;
obj.value = 123476;
obj.description = "this is my new object";
obj.mode = 1;
share|improve this question
Errm, do you mean creating an object in general or creating an actual System.Object and adding properties dynamically? – Yuck Jul 8 '11 at 14:29
add comment
4 Answers
up vote 12 down vote accepted
try c# anonymous classes
var obj = new {
 value = 123475,
 description = "this is my new object",
 mode = 1 };
there are lots of differences though...
_USER_ Kolupaev & _USER_ mentioned another approach with dynamic keyword
share|improve this answer
add comment
In case, it you want to create un-tyed object use ExpandoObject.
dynamic employee, manager;
employee = new ExpandoObject();
employee.Name = "John Smith";
employee.Age = 33;
manager = new ExpandoObject();
manager.Name = "Allison Brown";
manager.Age = 42;
manager.TeamSize = 10;
Your's other option is to use anonymous class, but this will work for you, only if you would use it in scope of method, since it can't be passed outside or as a parameter.
But, IMO, to take full advantage of C#, it's better to switch programming paradigm to strongly-typed, that is C# is designed for.
share|improve this answer
add comment
In C# you could do:
var obj = new SomeObject {
 value = 123476,
 description = "this is my new object",
 mode = 1
EDIT: Holding this here pending clarification from OP as I may have misunderstood his intentions.
share|improve this answer
add comment
The way to do this is you use C# 4.0 Dynamic types like Expando Object... see this topic:
How to create a class dynamically
share|improve this answer
add comment
Your Answer