text:
Oklahoma Fishery Research Laboratory, Norman, Oklahoma
The U.S. Fish and Wildlife Service as a part of their National Reservoir Research Program (NRRP) and the Oklahoma Department of Wildlife Conservation (ODWC) independently estimated angler-use on 25 Oklahoma reservoirs for 1975. The Fish and Wildlife Service utilized a multiple regression equation that relates fishing pressure to various physical parameters of 103 U.S. reservoirs in order to predict angler use. The ODWC utilized aerial observations. There was a positive relationship between NRRP predictions and ODWC estimates. However, compared to ODWC estimates the NRRP predictions of angler-use on these reservoirs were consistently higher. It is suggested that another factor, perhaps the ratio of fishing license sales to water surface area of a state or region, should be considered in the NRRP prediction.
The creel survey became a tool for evaluating management practices and predicting management needs as early as 1920 (1). Even today, however, one of the main problems facing fishery biologists is that of obtaining accurate creel survey estimates. Generally, the amount of time and effort available for a creel survey limits its accuracy. A total count and interview of all sport fishermen is often not economically feasible, and some form of abbreviated survey becomes necessary. Because few comparisons of actual data generated by these different methods have been made, it is difficult to select the best one. If several methods yield reasonably comparable results, there is a rational basis for choosing the least cumbersome. For this reason, the following comparison was made.
During _PHONE_ the Oklahoma Department of Wildlife Conservation (ODWC) initiated a creel survey on 47 Oklahoma impoundments greater than 200 hectares and on 17 small impoundments owned by the ODWC. After one year, estimates of harvest and angler use were obtained. Angler-use estimates for 25 of these reservoirs are shown in Table 1. Angler-use estimates were made by taking periodic counts from an aircraft. Although the periods between flights varied, counts were made on weekdays, weekends and major holidays during the year. The mean value for these counts was then multiplied by the annual number of daylight hours available for fishing. No estimate of nocturnal angler-use was attempted.
Prior to this census, the U.S. Fish and Wildlife Service under the National Reservoir Research Program (NRRP) compiled data for predicting fish production
in Oklahoma (2). This program also predicted angler-use on 50 Oklahoma reservoirs using a multiple regression prediction equation. Regression coefficients for this equation were obtained by relating data on diurnal angler-use of 103 United States reservoirs to various environmental variables of these reservoirs. Angler-use figures for the 103 reservoirs had been previously obtained by creel census techniques. Environmental variables used in the equation were reservoir age, total dissolved solids, length of growing season, surface area, and storage ratio. Both ODWC and NRRP estimates of angler-use are based on 4-hour angler-days.
In the present comparison, simple linear regression and correlation were used to relate the estimates of angler-use obtained by the two methods.
The NRRP predictions exceeded the ODWC estimates of angler-days for each reservoir (Table 1) by an average of nearly 64,000 days (Figure 1). In every case but one, the NRRP predictions exceeded the ODWC estimate. The data were positively correlated and the r value (0.7449) was significantly different from zero using a Student's t-test (P < 0.01) (3). Although perfect correlation of angler-use for each reservoir was not obtained, there was a definite positive relationship between the two methods. The least squares equation for the regression of NRRP predictions (Y) on ODWC prediction (X) was:
Y = 63899.5 + 1.160 X
Thus, an increase of 10,000 angler-days by the ODWC predictions was accompanied by an approximately equal increase of 11,600 angler-days by NRRP estimates. The increases shown by the two methods were, in fact, shown not to differ significantly: a Student's t-test (4) indicated the slope (b) of our equation did not significantly differ from 1.0 (P > 0.4).
In any large-scale creel survey the investigator must choose between a relatively expensive field census, such as was used to obtain the ODWC estimates, and a less expensive inferential model such as the NRRP equation.
In the present comparison, it appears that the NRRP equation was similar to the ODWC census in providing the order of angler-use for 25 Oklahoma reservoirs. For economic reasons, then, the NRRP equation would seem more practical for relative comparisons of angler-use between reservoirs. However, the NRRP equation produced consistently higher estimates of angler-use than the ODWC's aerial survey. Therefore, estimates based on reliable data obtained from the actual reservoirs in question are preferable to those obtained by use of the NRRP equation in cases where estimates of actual rather than relative values of angler-use are needed.
In examining the NRRP equation, one additional factor was found which may have merit for consideration if results from use of the equation are to become more comparable to ODWC estimates. While nonresident fishing may contribute a slight amount to the total angler effort, it is felt that the abundance of water area in relation to license sales is a factor presently limiting realization of the angler potential in Oklahoma as predicted by the NRRP equation. The average reservoir used to produce the NRRP equation was located in a state that had 2.01 times as many license holders per hectare of impounded water (reservoirs over 200 hectares) as Oklahoma. From data obtained from the U.S. Fish and Wildlife Service, it appears that Oklahoma sold only about 2 percent of the total annual fishing licenses in the United States in 1975 (636,494), although it ranked second in the total surface area of impounded water (238,760 hectares).
The authors wish to express their appreciation to Robert Jenkins of the U.S. Fish and Wildlife Service for providing information for this comparison. Work of the employees of the Enforcement and Fish Divisions of the Oklahoma Department of Wildlife Conservation in gathering data for the Creel Survey is appreciated. Funds for this investigation were obtained from Federal Aid in Fish Restoration under Dingell-Johnson Project F-15, State of Oklahoma.
1. V.E.F. SOLOMAN, Trans. N. Am. Wildlife Conf. 16: 225-233 (1951).
2. R. M. JENKINS, Ann. Okla. Acad. Sci. 5: 11-20 (1976).
3. R. R. SOKAL and F. J. ROHLF, Biometry, W. H. Freeman and Company, San Francisco, Cal., 1970.
4. R.G.D. STEEL and J. H. TORRIE, Principles and Procedures of Statistics, McGraw-Hill Book Company, Inc., New York, Toronto and London, 1960.


text:
Fluid dynamics of flapping wings associated with change of domain topology
Seminar Room 1, Newton Institute
We re-examine the clap-fling-sweep mechanism employed by some insects to increase lift. As argued by Lighthill (J Fluid Mech 60(1):1-17, 1973), this mechanism can create a circulatory motion even in a totally inviscid fluid, due to a topological change of the solid boundary that represents the wings surfaces. During the stroke, the wings first clap together behind the insect's back, then open in a fling motion around the 'hinge' formed by the two trailing edges, and finally separate at the hinge and sweep apart.
In a two-dimensional approximation, we use two different conformal mappings in simply and doubly connected domains, respectively, to calculate the complex potential at all stages of the process. The results indicate that circulation (equal in magnitude and opposite round the two wings) can be generated in an inviscid fluid, and that this circulation appears when a solid body immersed in the fluid breaks into two pieces (when fling gives way to sweep). Bound vortex sheets produced during fling are still carried by the just-separated wings. This is accompanied by a continuous time evolution of the velocity everywhere in the fluid, although the pressure field jumps instantaneously at the moment of wing separation.
In a viscous fluid, the flow during the break is essentially different because, locally, the Reynolds number is very low near the hinge point. We describe it by local similarity solutions to the Stokes equation (J Fluid Mech 676:572-606, 2011).
Three-dimensional effects are present in the flow. We study them by performing numerical simulations of the Navier-Stokes equations using a Fourier spectral method with volume penalization. The flow before the break is found to be in a good agreement with the two-dimensional approximation. After the wings move farther than one chord length apart, the three-dimensional nature of the flow becomes essential (J Fluids Struct 27(5-6):784-791, 2011).

source: HuggingFaceFW/fineweb-edu


text:
If you live near a major roadway, you may want to pay close attention. A new study has found a link between the onset of dementia and the proximity of your residence to highway traffic.
It's no secret that common air pollutants, particularly those associated with auto traffic, are bad for our health. But a team of researchers from Public Health Canada wanted to find out how these pollutants affect our brains. For the study, researchers tracked almost 7 million adults between the ages of 20 and 85 who lived in Ontario between 2002 and 2012. Using postal codes, they were able to determine which people lived near major roadways, with "major" defined as the equivalent of an interstate highway based on daily traffic volume. The team then compared this data with each person's medical records, looking specifically for three neurodegenerative conditions — Parkinson's disease, multiple sclerosis and dementia. The team's findings were published in The Lancet.
Researchers didn't find a link between living near a highway and a person's likelihood of developing Parkinson's or multiple sclerosis, possibly because the overall likelihood of developing these conditions is so small. But they did find a connection between living near a major roadway and a person's chances of developing dementia.
"There is something different going on with dementia," said Ray Copes, chief of environmental and occupational health at Public Health Ontario and a co-author of the study.
The numbers make the risk clear
Copes and his team found that living within 50 meters (about 164 feet) of a major roadway increased a person's chances of developing dementia by 4 percent. That likelihood decreased as the residential distance from the roadway increased. Those who lived 100 meters (328 feet) away from a major road were 4 percent more likely to develop dementia while those who lived between 101 and 200 meters (as far as a tenth of a mile away,) had an increased risk of 2 percent. Beyond 200 meters, the increase in dementia risk was negligible.
The link between dementia risk and residential proximity to a major roadway held strong even after researchers adjusted for factors such as education, body mass index, smoking or socioeconomic status. Next up, researchers are hoping to determine if there's one particular pollutant that is responsible for the link, or if noise plays a role.

source: openbmb/Ultra-FineWeb


How do I decide how many classes to take?
If you are an incoming frosh, we recommend signing up for 12-15 units of coursework in your first quarter. Keep in mind that adjusting to Stanford is at least the equivalent of a 3-unit course, so give yourself some room to breathe! After your first quarter, you can try taking on more if you like. In order to graduate in 4 years, you'll need to take an average of 15 units per quarter.
Important Deadlines
You will need to sign up for at least 12 units by the end of the first day of classes in order to be considered a full-time student. (See Also: What is a Unit?)
The official deadline to add and drop classes (Final Study List deadline) is the end of week three. However, while you can drop classes all the way through the third week, you should attend any classes you might take starting the first week of classes. Professors are often very reluctant to allow students to add a class that they have not been attending, and you may have missed work that cannot be made up.
After the third week of classes, your schedule for the quarter is set (the Final Study List deadline is 5pm on Friday of Week 3).
Things to consider as you choose the best combination
Number of classes
How many classes should you take? It depends. It depends on the classes, it depends on the workload, it depends on your other commitments, it depends on who you are and how you learn. This decision is best finalized after classes start--the ideal approach is to attend more classes than you expect to take, and by the end of Week 1, decide which of those classes make the best combination for you that quarter.
Typically, expect classes of 3-5 units to be main academic classes that can fulfill requirements and count toward a major, while classes of 1-2 units are usually lecture series or athletic classes, with fewer assignments outside class. Students will combine these in an infinite variety of ways.
12-15 units is ideal for your first quarter. The maximum number of academic units a first-quarter frosh may enroll in is 20. Students past their first quarter may request an exception to take 21 or 22 units in certain cases. See your Academic Advising Director or AARC advisor for details.
Cognitive shifting between types of studying/work often shows a better result than focusing in on one kind of learning. And it leads to less burn out. Most students do best with a balanced workload demanding a mix of exams and essays, of reading and problem sets, of STEM and humanities topics.
Four main academic classes may be nicely balanced among math, Spanish, chemistry, and history, but if you have two essays and two midterms all due in the same week, you might want to tweak something. It's useful to actually write down all the major deadlines on the Quarter-at-a-Glance planner, and then evaluate the commitments you are making.
Cardinal Compass - Secrets to Stanford Success
See Also


SOCIB participates in the JERICO Week #2, a meeting space for enhanced coastal observation in Europe
39 expert partners, representing 16 European countries, have taken part in the second edition of the JERICO Week (JERICO Week #2), a high-level scientific meeting held online from April 19 to 23, 2021. Among its participants, the Balearic Islands Coastal Observing and Forecasting System (SOCIB), member of the Horizon 2020 project JERICO-S3 (Joint European Research Infrastructure of Coastal Observatories: Science, Service, Sustainability), has actively engaged in its programme and participated through keynotes speeches on Modelling activities in JERICO-NEXT and JERICO-S3 and a session presenting e-JERICO and its status update, while delivering scientific excellence with impact on society. Furthermore, SOCIB has participated in several sessions of the JERICO Design Study (JERICO-DS) project, as both the WP3 (e-Infrastructure technical design and data integration strategy) leader and the Spanish national representative (in the context of the ESFRI roadmap of which JERICO RI aims to be part).
JERICO-S3 aims to provide a state-of-the-art, fit-for-purpose and visionary observational Research Infrastructure (RI), expertise and high-quality data on European coastal and shelf seas, supporting world-class research, high-impact innovation and a window of European excellence worldwide. Furthermore, it aims at significantly enhancing the current value and relevance of the JERICO-RI, through the implementation of the science and innovation strategy elaborated as part of the JERICO-NEXT project. JERICO-S3 is mainly targeting a more science integrative approach to better observe the coastal ecosystem, raising up the scientific excellence, with consideration of the regional and local ecosystems; the preliminary development of an e-infrastructure in support to scientists and users by offering access to dedicated services; progress on the design of the RI and its strategy for sustainability. The design of the JERICO-RI (both hardware and software components) will be covered by JERICO-DS, including cutting edge technologies from the sensor level to the information and service distribution to users, hence contributing to the Smart Ocean.
JERICO-S3 workshop on coastal model-observation integration
According to researchers, modelling, as one of the ocean monitoring instruments to provide a 4-Dimension continuous proxy and digital ocean, has been significantly advanced in the last two decades to cover physical, biogeochemical and high trophic marine systems. JERICO-S3 is a research infrastructure to improve EU multidisciplinary coastal ocean observations, but also has its own modelling activities. In this context, on Wednesday 21 April, Baptiste Mourre, researcher at SOCIB presented the past collaborative modelling activities in JERICO-NEXT and moderated a round table about coastal model-observation integration in the framework of a dedicated half-day workshop. During this workshop, researchers specifically discussed how coastal monitoring and modelling communities both in and outside JERICO could be benefited through model-observation integration and collaboration with non-JERICO modelling action and users.
JERICO-S3 session "e-JERICO presentation and status update"
Furthermore, on Thursday 22 April, Miguel Charcos, engineer at SOCIB, held a session presenting e-JERICO and its status update. e-JERICO is a unified central hub of JERICO to access all kinds of resources allowing the creation of advanced services based on the complete knowledge of the RI capabilities. Charcos informed partners about the development status of the e-infrastructure. The presentation included a review of the conceptual design, the impact, the status of the development and the main plans for the following months. It also included an overview of the relation with WP11 on virtual access led by SOCIB. Among its objectives, JERICO-S3 aims to facilitate virtual access to coastal ocean resources by providing a unique entry point for better discovery. Thus, reinforcing the whole coastal ocean value chain: from science to society.
Overall, the JERICO Week #2 engaged all partners in exploring new co-innovation pathways and strengthened its roadmap.


Question: What Got Into Me Meaning?
What did I get myself into meaning?
To get oneself into something means to become (by your own actions) involved or entangled in a situation; usually a difficult one.
"I didn't know what I was getting myself into": I didn't fully appreciate the consequences of my involvement (in the situation)..
What does GoT mean in slang?
Get on TaskGet on Task. GoT. Gospel of Thomas. showing only Slang/Internet Slang definitions (show all 27 definitions)
What got to you meaning?
From Longman Dictionary of Contemporary Englishget to somebody/something phrasal verb informal1 to make someone feel annoyed or upset I'm under a lot of pressure at work, and sometimes it gets to me a bit. Don't let things get to you.
What got you into it meaning?
1. Put simply, it means 'what is the matter with you?' To be more specific you are asking a person if something abnormal has happened or entered into the body causing him/her to act differently, like sweating too much when he is not supposed to.
What's the meaning of getting?
of Get. Getting(noun) the act of obtaining or acquiring; acquisition.
What does get off mean in a relationship?
Definition of get off with (someone) : to have sex with (someone) : to begin a sexual relationship with (someone) She found out he'd gotten off with another woman.
Have GoT it meaning?
From Longman Dictionary of Contemporary English I've got itused to say you have suddenly thought of the solution to a problem or that you suddenly understand a situation → have.
What does hitting on girl mean?
To "hit on someone" typically means that you are flirting with someone with the intent to enter into a romantic relationship with them. This can be applied to both short and long term relationships. To "pick up somebody" means to try and find someone to have a one-night stand with.
What does Ger mean?
Gross Enrolment RatioGross Enrolment Ratio (GER) or Gross Enrolment Index (GEI) is a statistical measure used in the education sector, and formerly by the UN in its Education Index, to determine the number of students enrolled in school at several different grade levels (like elementary, middle school and high school), and use it to show …
How do you use get in a sentence?
Use "getting" in a sentence | "getting" sentence examplesHe who would catch fish mush not mind getting wet.He who would catch fish must not mind getting wet.Getting the support of the Queen was a great encouragement to those involved in the project.She was very smug and self-satisfied about getting the promotion.More items…•
What means get laid?
get laid in American English Slang. to have sexual intercourse.
What does get into mean?
Meaning of get into sth in English to become interested in an activity or subject, or start being involved in an activity: She's been getting into yoga recently – she does three classes a week. SMART Vocabulary: related words and phrases.
What does off mean sexually?
(transitive, slang) To excite or arouse, especially in a sexual manner, as to cause to experience orgasm. (intransitive, slang) To experience great pleasure, especially sexual pleasure; in particular, to experience an orgasm. It takes more than a picture in a girlie magazine for me to get off.
What kind of word is getting?


Take the 2-minute tour ×
Three points $z_1$, $z_2$, $z_3$ on the complex plane are given by the coefficients $a_k$'s of the cubic polynomial $f(z)=(z-z_1)(z-z_2)(z-z_3)=\sum_{k=0}^3 a_k z^k$. How does one express the (signed) area $V$ of the triangle with vertices $z_1$, $z_2$, $z_3$ in terms of $a_k$'s and $\overline{a}_k$'s? One is tempted to try to expand $V^2$ in the symmetric functions in the roots of $f(z)\overline{f}(z)$, as well as these of $f(z)$ and of $\overline{f}(z)$, e.g. starting from $$ V=\frac{\sqrt{-1}}{4}\det \begin{pmatrix} 1& 1&1 \\ z_1&z_2&z_3 \\ \overline{z}_1&\overline{z}_2&\overline{z}_3\end{pmatrix}, $$ (this not so well-known formula can be found in R.Deaux, Introduction to the Geometry of Complex Numbers, Ungar, New York, 1956, pp.59-60), but this rather calls for some kind of joint invariants of $f$ and $\overline{f}$ to be used.
Any pointers etc. are much appreciated.
Added: the motivation comes from a moment problem: suppose one is given a part of the sequence $\mu_n=\int_\Delta t^n dx dy$, where $t:=x+\sqrt{-1}y$, and wants to find the triangle $\Delta$, e.g., its vertices $z_i$'s. P.Davis in his paper "Triangle formulas in the complex plane" (Math.Comp. 18(1964)) shows that the first 4 moments $V=\mu_0$,...,$\mu_3$ determine $\Delta$; this is one more parameter than needed to determine the $z_i$'s. We can do better, but were unsure how $V$ depends upon $\mu_1$,...,$\mu_3$, which boils down to this very question.
share|improve this question
the area with sign depends on the order of the points, so it cannot be expressed in terms of the symmetric functions $a_k$. – rita Nov 23 '11 at 9:28
But the square of the area is clearly a symmetric function... – Igor Rivin Nov 23 '11 at 9:31
The volume, or rather its square, is a symmetric polynomial in the three pairs $(x_1,y_1)$, $(x_2,y_2)$, $(x_3,y_3)$. So the geometric object underlying your hoped-for formula is not the symmetric cube of the complex affine line, but the symmetric cube of the affine plane. In other words, you need generators of the algebra $K[X_1,Y_1,X_2,Y_2,X_3,Y_3]^{\mathfrak S_3}$, where the symmetric groups acts via the obvious permutations. – ACL Nov 23 '11 at 10:58
Wouldn't you expect $V$ to be the root of a polynomial of degree $12$ whose coefficients are polynomials in the $a_k$ and $\bar a_k$? After all, the $a_k$ and $\bar a_k$ are fixed by two independent actions of $S_3$ and $V$ is only fixed by the diagonal $A_3$ action, so, in the worst case (which might hold), you'd expect the polynomial to have degree $(6\times6)/3 = 12$. Unless that polynomial factors, I wouldn't expect that there'd be a simpler formula. – Robert Bryant Nov 23 '11 at 13:22
Just out of curiosity, I checked (using Maple). The polynomial relating $(V,a_1,a_2,a_3,\bar a_1,\bar a_2,\bar a_3)$ is, indeed, irreducible of degree $12$ in $V$. (It is, of course, even in $V$.) It has total degree $22$ in these $7$ variables and is a sum of 646 monomials in these variables, with a typical integer coefficient having $7$ digits (when the highest common factor of the coefficients is $1$). I suppose I could paste the Maple output into an answer box if you wanted to see it, but, is there really any point to doing this? – Robert Bryant Nov 23 '11 at 16:38
5 Answers 5
up vote 13 down vote accepted
NB: Note that my $a_k$ have different signs from those defined in the question. For me, $$ (z - z_1)(z-z_2)(z-z_3) = z^3 - a_1\ z^2 + a_2\ z - a_3, $$ so that $a_k$ is the $k$-th elementary symmetric function of the $z_i$. This doesn't really affect the answer in any significant way.
While I don't think that the final result relating $V$ to the $a_k$ and $\bar a_k$ is that interesting or useful, people might want to know a way to derive it. Here is what I did: Start with the formula $$ V=\frac{\sqrt{-1}}{4}\det \begin{pmatrix} 1& 1&1 \\ z_1&z_2&z_3 \\ \overline{z}_1&\overline{z}_2&\overline{z}_3\end{pmatrix}, $$ and note that multiplying the matrix on the right by its transpose yields $$\begin{pmatrix} 1&1&1 \\ z_1&z_2&z_3 \\ \bar z_1&\bar z_2&\bar z_3\end{pmatrix} \begin{pmatrix} 1&z_1&\bar z_1\\ 1&z_2&\bar z_2\\ 1&z_3&\bar z_3\\\end{pmatrix} =\begin{pmatrix} 3&a_1&\bar a_1 \\ a_1&{a_1}^2-2a_2& S \\ \bar a_1&S&{\bar a_1}^2-2\bar a_2 \\ \end{pmatrix} $$ where $S = z_1\bar z_1 + z_2\bar z_2 + z_3\bar z_3$. Thus, one has the polynomial relation $$ R := 16V^2 - 3S^2 + 2 a_1\bar a_1 S + {a_1}^2{\bar a_1}^2 - 4{a_1}^2\bar a_2 - 4{\bar a_1}^2a_2 + 12 a_2 \bar a_2 = 0. $$ It remains to find a relation between $S$ and the $a_k$ and $\bar a_k$. To do this, note that $S$ will be a root of the polynomial $$ Q := \prod_{\pi\in S_3} \bigl(S - z_1{\bar z_{\pi(1)}} - z_2{\bar z_{\pi(2)}} - z_3{\bar z_{\pi(3)}}\bigr). $$ Note that $Q$ is a polynomial of degree $6$ in $S$ that is symmetric in the $z_i$ and the $\bar z_i$ separately. Hence, $Q$ can be regarded as a polynomial of degree $6$ in $S$ with coefficients that are polynomials in the $a_k$ and $\bar a_k$. The resulting expression for $Q$ as a polynomial in $S$, the $a_k$, and the $\bar a_k$ has $66$ terms. (Actually expressing $Q$ this way is not easy by hand. However, it's very easy to implement the algorithm for writing a symmetric polynomial in three variables as a polynomial in the elementary symmetric functions in those variables on a computer, which is what I did.)
Finally, $R$ and $Q$ are polynomials in $S$ with coefficients that are polynomials in the variables $V, a_1,a_2,a_3,\bar a_1,\bar a_2,\bar a_3$. Set $$ P(V,a_1,a_2,a_3,\bar a_1,\bar a_2,\bar a_3) := \text{Resultant}_S(R,Q). $$ Then $P=0$ is the desired relation. Computation (using Maple) shows that it has the following properties: $P$ is irreducible, is even and of degree $12$ in $V


assignment 1anchal asked 3 years ago
write a TCP client and tcp server program in c language on unix/linux where client program interact with the sever as given:the client begin by sending number to the server,sever program will check whether the number is prime or not,in case of number is prime the server send a message "successful attempt " to the respective clint,in case number is not prime server send message unsucessful attempt,this TCP can handle maximum 4 client concurrently?


Request to conserve water in Niseko and Soga areas
The Niseko and Soga areas mainly use spring water for tap water, but the amount of spring water is currently decreasing. This could be due to a decrease in precipitation last summer. Especially in the Niseko area, the water volume is less than 40% of the average year.
For the current shortage of water, we are pumping well water installed next to the Niseko area reservoir and distributing it. However, the water level of the well water is gradually decreasing, and the well water source may wither if the water is used in the same manner as it is now.
For that reason, we ask everyone who uses town water supply in the Niseko and Soga districts to take measures to save water.
Water saving example) ・ Close the faucet frequently when brushing your teeth or washing your hands.
- When washing dishes, pour water in the wash tub and wash.
- In a family with many families, take a bath at a united time
We apologize for any inconvenience, but please cooperate in saving water until the end of the normal drought season in early April.
If you have any questions, please contact Niseko Town government office water and sewage section.
Inquiries regarding information on this page
Water Supply and Drink Department


Test common rail piezo injectors
with DIT31 test bench
Massimiliano Gandini (IP)
Classic(Old) test Method
The most popular method to measure the flow of a common rail injector is to collect in a graduated glass the amount of liquid introduced during a known number of injections and compare this volume with the graduation of the container.
Deteq test Method
An alternative able to provide higher resolution, is to split the flow in its two fundamental physical parameters: that is,
- the time interval between opening and closing of the nozzle (injection time).
- pressure difference during the injection time
Piezoelectric actuator control requires the additional CRP module to the unit TC38.
Test 1:Minimum pressure
Activated the automatic triggering cycle, it is easy to find the minimum pressure which allows the chatter.
Test 2: Chatter
Test 3: Return
With the injector pressurized, the pump is stopped and the pressure drops gradually, depending on the return.
Test 4: Seat Leackage
Known the acceptable leckage time, any lower value indicates a too high back leackage.
The injector on the left has an acceptable quantity of return; the other one on the right has an extra internal leakage.
Test 5: Opening Delay
Opening delay is the time to translate the electrical command into a mechanical movement
Injection time is the time elapsed between the opening and closing of the nozzle.
It is essential to determine the flow.
On the left an injector that pulverizes exactly on time, on the right an injector that responds with a delay.
For each chatter, at constant pressure DIT31 calculates the difference between the level of pressure on opening and closing of the nozzle.
This parameter, together with the injection time, determines the amount of the injected fluid.
On the left, the injector injects the correct amount. The injector in the center has at least one of the nozzle holes with a reduced diameter by dirt or oxide while the nozzle holes of the injector on the right are expanded by wear.
This component is an Upgrade.
PiezoDevice 87.20.116 is the specific device to be used on an exhisting DIT31 test bench for diesel injectors.
The device has been developed to solve a particular situation rising when testing piezo common rail injectors, as the piezo actuator must result lubricated before being energized. On the contrary the piezo actuator may be damaged


What is the stitch length regulator on a sewing machine?
A stitch regulator is a tiny computer attached to a sewing machine that constantly adjusts the machine's stitch speed to accommodate the speed of the fabric during free-motion stitching. This ensures balanced, equal-length stitches.
What sewing machines have a stitch regulator?
Bernina is the only home sewing machine brand with stitch regulated technology built-in. I used the Bernina Stitch Regulator to quilt all my Stitching Cosmos quilts!
How do you fix the stitch length on a sewing machine?
Adjusting the stitch length (For models equipped with the stitch length dial)
 1. Raise the needle by turning the handwheel toward you (counterclockwise) so that the mark on the wheel points up.
 2. Turn the stitch length dial to adjust the stitch length that you want to sew.
What is the normal stitch length?
IT IS INTERESTING: Can the Cricut maker embroidery?
Can I quilt with a regular sewing machine?
What stitch length should I use for machine quilting?
What is the best stitch length for sewing a straight stitch?
What is the best stitch length for free motion quilting?
Yes, for free motion quilting, set your stitch length to '0'. That way your feed dogs won't be moving while you're quilting because you don't need them. Less wear and tear on those parts.
Basic Settings for Sewing Straight Stitches on a Sewing Machine
 - Stitch Length: 2.5mm or 10 (stitches per inch)
 - Stitch Width: needle centered over stitch plate*
 - Stitch Tension: 4.
How do you troubleshoot a sewing machine stitch?
21 Stitching Problems On Sewing Machines (and easy solutions)
 1. Check the needles isn't bent.
 2. Check the needle size.
 3. Let the machine pull the fabric at its own speed.
 4. Use a table to catch the fabric.
 5. Needle and thread must match.
 6. Check the timing of the machine.
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Why is my sewing machine making long stitches?
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January 10, 2012
On December 7, 2011, Neil deGrasse Tyson tweeted:
Need a distraction today? Not only does 12+1=11+2, but the letters "twelve plus one" rearrange to give you "eleven plus two"
Mitchell Perilstein forwarded that tweet to me and suggested that it would form the basis of an exercise for Programming Praxis.
Your task is to write a program that finds equations similar to Tyson's that form anagrams both in their symbols and in their letters. When you are finished, you are welcome to read or run a suggested solution, or to post your own solution or discuss the exercise in the comments below.
Pages: 1 2


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Полные правила Magic: the Gathering
601.1 Previously, the action of casting a spell, or casting a card as a spell, was referred to on cards as "playing" that spell or that card. Cards that were printed with that text have received errata in the Oracle card reference so they now refer to "casting" that spell or that card.
601.1a Some effects still refer to "playing" a card. "Playing a card" means playing that card as a land or casting that card as a spell, whichever is appropriate.
601.2 To cast a spell is to take it from where it is (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. Casting a spell includes proposal of the spell (rules 601.2a–d) and determination and payment of costs (rules 601.2f–h). To cast a spell, a player follows the steps listed below, in order. A player must be legally allowed to cast the spell to begin this process (see rule 601.3), ignoring any effect that would prohibit that spell from being cast based on information determined during that spell's proposal. (Such effects are considered during the check detailed in rule 601.2e.) If, at any point during the casting of a spell, a player is unable to comply with any of the steps listed below, the casting of the spell is illegal; the game returns to the moment before the casting of that spell was proposed (see rule 720, "Handling Illegal Actions").
601.2a To propose the casting of a spell, a player first moves that card (or that copy of a card) from where it is to the stack. It becomes the topmost object on the stack. It has all the characteristics of the card (or the copy of a card) associated with it, and that player becomes its controller. The spell remains on the stack until it's countered, it resolves, or an effect moves it elsewhere.
601.2b If the spell is modal, the player announces the mode choice (see rule 700.2). If the player wishes to splice any cards onto the spell (see rule 702.46), he or she reveals those cards in his or her hand. If the spell has alternative or additional costs that will be paid as it's being cast such as buyback or kicker costs (see rules 117.8 and 117.9), the player announces his or her intentions to pay any or all of those costs (see rule 601.2f). A player can't apply two alternative methods of casting or two alternative costs to a single spell. If the spell has a variable cost that will be paid as it's being cast (such as an in its mana cost; see rule 107.3), the player announces the value of that variable. If the value of that variable is defined in the text of the spell by a choice that player would make later in the announcement or resolution of the spell, that player makes that choice at this time instead of that later time. If a cost that will be paid as the spell is being cast includes hybrid mana symbols, the player announces the nonhybrid equivalent cost he or she intends to pay. If a cost that will be paid as the spell is being cast includes Phyrexian mana symbols, the player announces whether he or she intends to pay 2 life or the corresponding colored mana cost for each of those symbols. Previously made choices (such as choosing to cast a spell with flashback from a graveyard or choosing to cast a creature with morph face down) may restrict the player's options when making these choices.
601.2c The player announces his or her choice of an appropriate player, object, or zone for each target the spell requires. A spell may require some targets only if an alternative or additional cost (such as a buyback or kicker cost), or a particular mode, was chosen for it; otherwise, the spell is cast as though it did not require those targets. If the spell has a variable number of targets, the player announces how many targets he or she will choose before he or she announces those targets. In some cases, the number of targets will be defined by the spell's text. Once the number of targets the spell has is determined, that number doesn't change, even if the information used to determine the number of targets does.The same target can't be chosen multiple times for any one instance of the word "target" on the spell. However, if the spell uses the word "target" in multiple places, the same object, player, or zone can be chosen once for each instance of the word "target" (as long as it fits the targeting criteria). If any effects say that an object or player must be chosen as a target, the player chooses targets so that he or she obeys the maximum possible number of such effects without violating any rules or effects that say that an object or player can't be chosen as a target. The chosen players, objects, and/or zones each become a target of that spell. (Any abilities that trigger when those players, objects, and/or zones become the target of a spell trigger at this point; they'll wait to be put on the stack until the spell has finished being cast.)
601.2d If the spell requires the player to divide or distribute an effect (such as damage or counters) among one or more targets, the player announces the division. Each of these targets must receive at least one of whatever is being divided.
601.2e The game checks to see if the proposed spell can legally be cast. If the proposed spell is illegal, the game returns to the moment before the casting of that spell was proposed(see rule 720, "Handling Illegal Actions").
601.2fThe player determines the total cost of the spell. Usually this is just the mana cost. Some spells have additional or alternative costs. Some effects may increase or reduce the cost to pay, or may provide other alternative costs. Costs may include paying mana, tapping permanents, sacrificing permanents, discarding cards, and so on. The total cost is the mana cost or alternative cost (as determined in rule 601.2b), plus all additional costs and cost increases, and minus all cost reductions. If multiple cost reductions apply, the player may apply them in any order. If the mana component of the total cost is reduced to nothing by cost reduction effects, it is considered to be. It can't be reduced to less than. Once the total cost is determined, any effects that directly affect the total cost are applied. Then the resulting total cost becomes "locked in." If effects would change the total cost after this time, they have no effect.
601.2g If the total cost includes a mana payment, the player then has a chance to activate mana abilities (see rule 605, "Mana Abilities"). Mana abilities must be activated before costs are paid.
601.2h The player pays the total cost in any order. Partial payments are not allowed. Unpayable costs can't be paid.
601.2i Once the steps described in 601.2a–h are completed, effects that modify the characteristics of the spell as it's cast are applied, thenthe spell becomes cast. Any abilities that trigger when a spell is cast or put onto the stack trigger at this time. If the spell's controller had priority before casting it, he or she gets priority.
601.3 A player can't begin to cast a spell unless a rule or effect allows that player to cast it. If that player is no longer allowed to cast that spell after completing its proposal, the casting of the spell is illegal and the game returns to the moment before the casting of that spell was proposed(see rule 720, "Handling Illegal Actions").
601.3a If an effect allows a player to cast a spell as though it had flash only if an alternative or additional cost is paid, that player may begin to cast that spell as though it had flash.
601.3b If an effect allows a player to cast a spell with certain characteristics as though it had flash, that player may consider any choices to be made during that spell's proposal that may cause it to have those characteristics. If any such choices could cause it to match these characteristics, that player may begin to cast that spell.
601.4 Some spells specify that one of their controller's opponents does something the controller would normally do while it's being cast, such as choose a mode or choose targets. In these cases, the opponent does so when the spell's controller normally would do so.
601.4a If there is more than one opponent who could make such a choice, the spell's controller decides which of those opponents will make the choice.
601.4b If the spell instructs its controller and another player to do something at the same time as the spell is being cast, the spell's controller goes first, then the other player. This is an exception to rule 101.4.
601.5 Casting a spell that alters costs won't affect spells and abilities that are already on the stack.
6. Spells, Abilities, and Effects
<< 600. General
6. Spells, Abilities, and Effects
602. Activating Activated Abilities >>


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It's how grocery stores manage the freshness of their inventories, and it's how customers know they're getting a safe product. If the expiration date is smudged during printing, packaging, or transportation, store policy may not allow the product to reach the shelf. Even if that smudged product does reach the shelf, customers may avoid it altogether. Poorly printed expiration dates can lead to wasted product and materials.
Choosing the best expiration date stamp for plastic bottles helps prevent this waste. It also helps to simplify the lives of retail stock and auditing staff—leading to better relations with your retail partners and a better grip on the bottom line.
Food and Drug Administration Product Dating Requirements
The expiration stamps for plastic bottles are a type of food product dating that is governed by the Food and Drug Administration (FDA). The only food product for which an expiration date is required by federal law is infant formula. In all other cases, it's voluntarily provided by the manufacturer.
There are two types of dates that might be found on a plastic bottle. On the one hand, you have the date of bottling for a product: what FDA terms a "closed" date. On the other hand, expiration dates fall under a different category termed "open" dating.
The only requirements the FDA sets for open dating is that it not be misleading to the customer. In other words, it should be prefaced by terminology like "best by," that makes it clear that the date is a suggestion and not a hard and fast rule for disposal by that date. In the case of long-lasting, shelf-stable, or frozen products, open dating must include the year as well as the month and day. Whether a manufacturer is using an open date expiration stamp for plastic bottles or a closed date that shows when the product was bottled, the printing challenges are going to be largely the same—related to plastic type, shape, and volume.
Printing on Different Types of Plastics
The plastics that are typically used for bottles and other containers are thermoplastics: a range of different plastics that can be heated up, molded into the desired shape, and then heated up again and molded into a new form. It's this resiliency that allows most plastic bottles to be recycled. Within this category, there are several different types of plastics that are commonly used to make plastic bottles for consumer products.
Some of the particular plastic surfaces you might be dealing with include:
- Polyethylene terephthalate (PET): PET has a very smooth, non-absorbent surface, similar to glass.
- Polycarbonate (PC): Polycarbonate plastic is strong and translucent with a higher gloss finish that imitates glass.
- Low-Density Polyethylene (LDPE): LDPE is lightweight, robust, and squeezable for contents like condiments—and it's a more expensive material.
- High-Density Polyethylene (HDPE): HDPE is a denser and less-expensive version of LDPE. It has a high resistance to stronger solvents and creates a stronger scent barrier, but it's not as smooth as many other plastic types.
- Polypropylene (PP): Polypropylene is highly resistant to heat and is commonly used to make bottle caps.
- Polyvinyl Chloride (PVC): PVC provides a particularly strong barrier—against oils, odors, and gases—making it ideal for cleaners and other household products. Well known for the inclusion of plasticizers, PVC may not be approved for use alongside products for human consumption.
The challenges of printing on different types of plastics are only party due to the differences of the plastic surface. Specifically, PET, PP, and PC plastics all present a notably smoother surface than that of plastics like HDPE. But the curves of a bottle present a whole new challenge. And the properties of the materials that go inside of these bottles can present just as much of a problem for printing and stamping.
A soy sauce bottle with a glossy coating of polycarbonate will provide a challenge not only because of the smooth surface, but also because an expiration date for plastic bottles containing soy sauce must be printed in an ink that contrasts with the dark liquid. Milk bottles will be labeled while cold, and moisture condensing on their surface may present additional problems for printing that must be solved up front. You need to understand the particular conditions you're printing under as you approach a solution. These challenges—and many others—can be addressed through the choice of a quality ink and printer.
Printing an Expiration Date Stamp for Plastic Bottles
Issues like smooth surfaces and condensation are best addressed with a quick-drying ink that hardens as it dries. These are inks that can also be used to print dates on glass surfaces. It may surprise you to learn that a carefully designed inkjet printer can easily manage bottle curvatures and concavity and print quick-drying inks on a variety of different plastic surfaces. These printers can manage this critical job for product volumes much greater than other types of expiration date stamps can manage for plastic bottles—providing a more consistent, reliable solution overall.


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Understanding the Use of Non-Motorized Transportation Facilities
Greg Lindsey, Kristopher Hoff, Steve Hankey, Xize Wang
Report no. CTS 12-24
Traffic counts and models for describing use of non-motorized facilities such as sidewalks, bike lanes, and trails are generally unavailable. Because transportation officials lack the data and tools needed to estimate use of facilities, their ability to make evidence-based choices among investment alternatives is limited. This report describes and assesses manual and automated methods of counting non-motorized traffic; summarizes counts of cyclists and pedestrians in Minneapolis, Minnesota; develops scaling factors to describe temporal patterns in non-motorized traffic volumes; validates models for estimating traffic using ordinary least squares and negative binomial regressions; and estimates bicycle and pedestrian traffic volumes for every street in Minneapolis. Research shows that automated counters are sufficiently accurate for most purposes. Automated counter error rates vary as a function of type of technology and traffic mode and volume. Across all locations, mean pedestrian traffic (51/hour) exceeded mean bicycle traffic (38/hour) by 35 percent. One-hour counts were highly correlated with 12-hour "daily" counts. Significant correlates of non-motorized traffic vary by mode and include weather (temperature, precipitation), neighborhood socio-demographics (household income, education), built environment characteristics (land use mix), and street (or bicycle facility) type. When controlling for these factors, bicycle traffic, but not pedestrian traffic, increased over time and was higher on streets with bicycle facilities than without (and highest on off-street facilities). These new models can be used to estimate non-motorized traffic where counts are unavailable and to estimate changes associated with infrastructure improvements.


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Improving environmental outcomes for low income households in Marrickville
The concept of "green equity" - assisting low and modest income households in meeting the challenges of climate change - has only recently been introduced to Australia but is rapidly evolving.
Local councils have a key role to play, given that they are close to the communities they serve and are in a good position to target environmental initiatives to low income households that would normally have the least capacity to take advantage of such initiatives.
There are now opportunities for Marrickville Council to take a leading position on 'green equity' and to examine policy measures to assist low income households within the area to improve environmental outcomes and wellbeing.
For information on the strategies Council is implementing to improve environmental outcomes for low income households in the area, please download the following documents:
Anti Poverty Week presentation: Climate Change and its Social Impacts
During Anti Poverty Week 2007, Marrickville Council organised the Forum on Climate Change and its Social Impacts at the Petersham Town Hall to identify and discuss the equity issues associated with climate change.
The Forum highlighted:
You can download the PDF versions of the multimedia presentations below.


Daily News Egypt
Minister of Electricity reveals mechanisms of access to nuclear fuel, ways to dispose of it - Daily News Egypt
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Shaker explains terms of IAEA and Russian company to create El-Dabaa nuclear power plant
By Salah El-Menoufi
The electricity sector is facing several challenges with the unprecedented increase of consumption rates because of population growth, limited sources of fuel, and its price increase. The government is seeking to achieve high rates of economic growth, which requires the provision of more energy sources.
In an interview with Daily News Egypt, Minister of Electricity Mohammed Shaker revealed the ministry's plans to meet the energy shortage crisis, reduce waste, secure supplies, and rationalise consumption. The El-Dabaa nuclear power plant and means of access to nuclear fuel and securing its disposal has become a priority file for the government.
What are the challenges the energy sector is facing now?
The electricity sector has been facing many challenges in recent years. Among the challenges are unprecedented increases of consumption of electricity due to high population growth rates, economic growth increase in losses in the electrical transmission, distribution networks thefts, and the stability of electricity prices for long periods of time despite the increase in production requirements and increase in subsidy bills.
The challenges also include the difficulty of managing the necessary funds and the lack of funding for new projects in streamlining and improving energy efficiency.
The increased cost of renewable energies forced us to find a balanced mix of energy between the traditional with coal, the renewable with hydro, solar, wind, subsoil, and wastes, and nuclear.
The minister discussed the challenges facing the energy sector (AFP Photo)
The minister discussed the challenges facing the energy sector
(AFP Photo)
What are strategic goals of the electricity sector?
Goals include maximising the use of all resources, encouraging the use of renewable energy, and promoting electricity interconnection. We also aim to improve the efficiency of energy production and its usage by adopting environmental protection policies and appropriate measures in the field of electricity generation and future planning to meet the rising demands.
What are procedures for securing disposal of nuclear fuel after operating the plants?
Egypt's strategy for the management of nuclear fuel of high radiation includes two aspects; the temporary storage and awaiting the examination of all technical and economic considerations associated with the subsequent stage. The nuclear fuel is then stored gradually in water basins to alleviate radiation of the fuel as well as providing suitable means for cooling so that the heat emitted from it could be extracted on an ongoing basis.
Afterwards the fuel is transferred, in accordance with the general policy of the state, for reprocessing and separation of some fission products useful for medical, agricultural, and industrial uses.
The disposal of radioactive waste results from scrapping the power plant when the operational life of the plant ends or in case of accidents. This is according to the plan submitted by the main contractor of the project.
This is why they must be reviewed during scrapping operations plans and updated regularly according to the technological development in this regard.
What is the plan prepared by ministry to secure nuclear fuel supplies?
The strategy for guaranteeing secure supply of nuclear fuel and waste disposal is based on the conclusion of multiple long-term contracts with more than one supplier to ensure the supply of materials and services.
At the beginning of implementation of the Egyptian nuclear programme, the supplier company will be obliged to provide the necessary nuclear fuel for the operation of nuclear reactor for a period ranging between five and ten years.
A strategic stockpile of fuel will be provided to ensure its availability if supply from abroad was interrupted for any reason. There will also be special facilities for storing nuclear fuel. It will be emphasised on in the contracts to be signed with the company that will implement the project.
What type of fuel will be used in Al-Dabaa plant?
Universally available nuclear fuel, which is uranium dioxide and mixed oxide fuel.
What are the procedures for dealing with waste?
Disposal of low and medium-level radioactive waste will be done by processing at the power plant with modern and sophisticated technologies, supplied by the main contractor for the nuclear power plant project.
The contractor, the Russian corporation Rosatom, handles equipping a cell at the fuel basin to secure the processing hardware and contaminated equipment.
There will also be an accurate system of operations associated with the management of radioactive waste – assembly, classification, transport, and storage – and keeping these operations under constant monitoring, verification, and audit. This will be through the establishment of an accounting system for all sorts of radioactive waste resulting from operation.
The establishment of a nuclear power plant requires the availability of an efficient electricity network to begin commercial operational for a nuclear plant, which is significant for the high electrical capacities generated from the plants.
The nuclear programme requires highly trained human cadres on all project levels, from choosing the site until operating it.
What are the additional requirements?
Nuclear plants' projects depend on communication between the project's parties and the beneficiaries to ensure the best performance in planed times. Therefore the IAEA requires participating with the participation of all the project stakeholders.
There are also terms to provide the highest levels of environment protection surrounding the plant's site and to elaborate an emergency plan. These terms are an essential part of the infrastructure to stress on the procedures followed during emergency and to be prepared for it.
Through which mechanisms will the ministry operate to increase energy?
We are working through four mechanisms including government's project via NREA, the private sector projects through the Build, Own and Operate (BOO) system, commercial projects, and the feed-in tariff.
The law allows investors to provide the necessary lands to establish state's projects represented in the NREA for a 2% beneficial right from the project's produced energy value.
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text:
PHY vs MAC | Difference between PHY layer,MAC layer
This page compares PHY vs MAC layers and mention difference between PHY layer and MAC layer. This page on PHY vs MAC helps reader understand basics of PHY layer such as what is phy medium used, frequency, data rate, modulation, code rate and so on. PHY and MAC layers of wlan, wimax, zigbee, zwave, bluetooth are also mentioned.
Both of these are layers reside in OSI stack or OSI 7 layer model. They have their own functions as well as they support each other in order to provide reliable communication between peer network layers of two IP enabled devices. Layer-1 is known as PHY and Layer-2 is known as MAC. Figure depicts positions of these layers in OSI stack.
What is PHY Layer
PHY is the short form of Physical Layer or medium. It is the layer-1 in OSI stack. It interfaces physical medium with MAC and upper layers. Physical medium can be copper wire, fiber optic cable, twisted pair or even wireless channel.
Following are the functions of PHY layer:
- It converts MAC layer format suitable to be transported over the medium.
- It adds forward error correction functionality to enable error correction at the receiver.
- It adds modulation and demodulation modules to incorporate modulation and demodulation functionalities. This will convert bits into symbols for long distance transmission as well as to increase bandwidth efficiency.
Following table-1 mentions what are different physical layers as per different wireless and wired standards. The variation in physical layer depends on medium requirement and system performance requirement (i.e. BER, SNR, spectral efficiency or Bandwidth efficiency, power efficiency). Different PHY layers will have different FEC configurations and modulation formats.
What is MAC Layer
MAC is the short form of Medium Access Control Layer. It is the layer-2 in OSI stack. It interfaces PHY layer and Upper layers (i.e. network and above).
Following are the functions of MAC layer:
- It incorporates MAC header at the start of upper layer IP packet and CRC at the end of IP packet. MAC header includes packet length field which will help receiver know about total length of packet it is going to receive. CRC will help in error detection. It will help receiver know whether received packet is erroneous or not.
- Incorporates ARQ functionality as a means for requesting retransmission in case of errors. This retransmission request is initiated by the receiver to the transmitter.
- Takes care of resource allocation and maintenance for the requesting subscribers or clients of the service.
- Enable flow control by segmentation (at transmit end) and re-assembly (at receive end) of packets. This is also known as fragmentation and reassembly. The size of the segmentation depends on transport payload of the medium. For example, in case of OFDM based systems such as wimax or wlan, the payload size depends on number of data carriers in a symbol or slot.
Following table-2 mentions MAC layers of various standards.
|MAC Layer||RF Wireless World Reference link|
|WLAN MAC as per 11a and 11ac standard||
WLAN MAC Layer-1➤
WLAN MAC Layer-2➤
WLAN 11ac MAC Layer➤
|WiMAX MAC Layer as per IEEE 802.16d standard||WiMAX MAC layer as per OFDM➤|
|Zigbee MAC Layer||Zigbee MAC layer➤|
|Bluetooth MAC||Bluetooth MAC layer➤|
|Zwave MAC||Zwave MAC layer➤|
|WBAN MAC||WBAN MAC layer➤|


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Come Holy Spirit Renew the Creation
St. Gregorios Orthodox Church,
"The voice of the Lord breaks the cedars; the Lord breaks in pieces the cedars of Lebanon" –Psalms 29: 5
The cedars of Lebanon (Cedrus libani) are mentioned frequently throughout the Old Testament (see Ezekiel 31:3, Psalm 104:16, Amos 2:9). These coniferous trees are well known for their height (up to 130 feet) and massive trunk (up to 8 feet in diameter). In Biblical times, these trees were highly valuable due to their superior building quality----even King Solomon found it worthy enough to build his temple in Jerusalem with (1 Kings 5:6). The psalmist is well aware of its features when referring to the cedars to describe the power and strength of the Lord.
When considering the cedars of Lebanon, we can find that many of its characteristics are in line with how we should live our own lives:
UsefulNot only do these trees provide an excellent source of timber, they also provide shelter to birds and other living things. We should lead a life where we are of use to those around us. Consider: How useful have we been this week to others in our life?
RootedFor every ten feet that these cedars are above ground, the roots below go down 30 feet! Being deeply rooted is what allows these timbers to stand upright through many storms and other natural disasters. If we are to grow in Christ, we must first be rooted in Him. When we stand firm in God's love for us, we are better able to withstand the storms of grief, disappointment, and pain. Consider: Are we deeply rooted in Christ? Do the roots go beyond what others can see?
CooperativeWhen there are neighboring trees around, cedars will often intertwine and grow together as one. If one tree becomes weak, its limbs will be sustained by merging with the healthy tree. We are expected to carry the weak amongst us and also allow others to carry us when we are weary. Consider: Have we been able to bear the burden of those in need? Have we accepted help from others in times of struggle?
As we read the entirety of Psalms 29, it seems that the psalmist is in the middle of a thunderstorm while hearing the voice of the Lord. Just how powerful is His voice? Powerful enough to break the cedars of Lebanon. Let us grow to be like the cedars of Lebanon (Psalms 92:12), while keeping in mind the awesome power of God who sits as King forever.
Heavenly Father, thank You for being the God of judgment, strength, and power over all the earth. We pray that we can be more like the cedars of Lebanon. Help us to be useful to those around us, deeply rooted in You, and cooperative with others. We love You for all that You do for us. In Jesus' name we pray, Amen.
THOUGHT FOR THE DAY:
It's impossible even for the devil to cut down a tree that is so deeply rooted, so useful, and so cooperative.


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Doe's any one know the history behind, or background of the multiple naming conventions for the equivalent risk functions. Different quant authors prefer using different names, does any one know why? which came first? why do some quants prefer one over the other. What is the history behind all of this.
ES - expected shortfall
CVaR - conditional value at risk
AVaR - average value at risk
ETL - expected tail loss
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Possibly the biggest road block to learning statistics are the varied and nonsensical naming. "[...]bad names reflect (or even result in) difficulties in understanding." Hurst, Joseph, colours and noises: The importance of names in an important natural behaviour, Demetris Koutsoyiannis itia.ntua.gr/getfile/792/1/documents/… – montyhall Mar 15 '13 at 5:40
2 Answers 2
No specific history. I'm not aware who introduced this measure initially. Most probably it came up as an example in the research papers on coherent risk measure. All names make sense to some extent:
Expected shortfall - as it's an expectation of losses
Conditional Value at Risk - as it can be written as $E[X |X >VaR_α(X)]$, i.e. conditional expectation
Average value at risk - as it can be written as $\frac{1}{1-\alpha}\int_{\alpha}^1VaR_{\beta}(X)d\beta$, which is essentially an average Expected Tail Loss - as it's expectation calculated in the tail of loss distribution
It's also sometimes called Tail VaR.
Personal preferences of people are usually based on their favorite risk management reference book.
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I have also seen (in rough decreasing importance order): Mean excess loss, Tail conditional expectation and the variant C.T.E., Tail mean, Mean shortfall...
AVaR doesn't seem as common as the other three you mentioned.
Acerbi&Tasche 2002 discuss the difference between CVaR and ES. In practice there's little mention on reasons for each choice and rarely any differences have a significant role so that all variants become equivalent. The different naming flavours mostly originate historically from various areas: very roughly (from my concentrated and relatively limited sample) CVaR seems more en vogue among economists&traders, ES among risk managers, ETL among "statisticians", TVaR in econometrics, CTE among actuaries etc...
For other formulations of ES check also spectral and distortion risk measures.
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The Abbey Library of Saint Gall was founded by Saint Othmar, the founder of the Abbey of St. Gall. The library collection is the oldest in Switzerland, and is one of earliest and most important monastic libraries in the world. It holds 2,100 manuscripts dating back to the 8th through the 15th centuries, 1,650 incunabula (printed before 1500), and old printed books. The library holds almost 160,000 volumes. The manuscript B of the Nibelungenlied is kept here.
Photo and description found at TwistedSifter(dot)com.


Romance or romantic? I like romantic movies or I like romance movies? are both correct? Also, a friend of mine said it's all right to say: It's a romantic movie. But it's wrong to say: It's a romance movie. Why is that? Thanks!
Jul 6, 2015 2:22 PM
Answers · 4
"Romance movie" is absolutely correct and more common than "romantic movie". ROMANTIC is an adjective. "A romantic movie/book" "A romantic night" "A romantic poem/story" ROMANCE is a noun. "It was a short-lived romance" It can also be an adjective when used to describe a type of writing: romance novels.
July 6, 2015
I would disagree with Marcin about 'romance movie' being more common than 'romantic movie'. Certainly you can say that the story is 'a romance', the same way as you'd describe a story as 'a thriller', but I would always use the adjective form before'movie' or film: 'a romantic movie' or 'a romantic film'. Out of curiosity, I googled this and found one or two references to 'romance movie' and dozens to 'romantic movie'. This could be a regional difference, but I have never actually heard anyone say 'romance movie'.
July 6, 2015
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I have installed Ubuntu 9.04 and am having a problem that I can connect from the server to the outside world but cannot connect to the server. I checked all of the different firewall systems (firestarter, ufw, iptables, etc.) and all are disabled. When I try to ssh, ping, etc. to the server they all timeout.
I am running on a wireless network and the router recognizes that the machine is connected to the network (with the proper ip address) but even the router cannot ping the server.
Any ideas?
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2 Answers 2
You have to ensure you are using your router's IP address when trying to access an internal node. If you are trying to ping the IP assigned to your server from your router, that is an internal IP (something like and pinging that from outside your router will do nothing, it will try to find the node on the same network you are pinging from.
To ensure access to your server, forward ports in your router to your server. Port 22 must be opened and point towards your server's internal IP address to use SSH.
To find your router's IP address, you can navigate to WhatIsMyIp.org from the server, it will display your router's address on the internet. Your router's administration page should also display this data. When using ping, you will be pinging your router as well, not the server, unless you specify a port that is forwarded to the server, then it will tell you if the node is reachable.
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does the router have a firewall? -check the settings thereespecially port forwarding. I'd also check if openssh-server is installed.
Also, its HIGHLY unusual to have a server on wireless.
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text:
The notion of shapeshifting has been around for nearly as long as human beings. The possibility that a person can take the shape of another being—most often an animal—can be traced back thousands of years, permeating various cultures and religions. While transmogrification has been widely valued in various religious mythologies, there is also evidence of its influence in pseudo-historical (possibly historical) records.
Shapeshifting in Fairy Tales and Myth
Shapeshifting appears very often in fairy tales and myths. In tales from Greek mythology, Zeus transformed into countless creatures, such as a swan, a bull, and an ant. The myths of the Egyptians depicted the gods with the heads of animals, as seen in the bird head of Horus and the dog head of Anubis, while the myths of the Norsemen showed the mischievous god Loki change into a giant, a woman, and various animals. More recently, in the well-known tale recorded by the Brothers Grimm, The Frog Prince (written in the 19th century), the male protagonist was changed into a frog for a mistake he made in his past.
Illustration of The Frog Prince, P. Meyerheim (Wikimedia Commons)
It is considered likely that the earliest depictions of shapeshifting capabilities comes from the Cave of the Trois-Frères, located in southern France. Though the purposes behind the images discovered there are constantly up for debate, and are unlikely to be definitively decrypted in the near future, many scholars believe that some of these drawings indicate a pre-historic belief in the ritual of transformation.
The cave's depiction of "The Sorcerer", for example, gives the impression of both animal and human parts, his awkward position explained by placing him in the physical moment of alteration. If modern scholars are right about this, then beliefs in shapeshifting and transmogrification can be traced all the way back to 13,000 BC.


text:
The purpose of this study was to investigate the changes in patient subjective happiness and satisfaction with cataract surgery and evaluate the association between satisfaction and types of cataract. This study surveyed 247 participants (mean age, 67.9 years) and they completed questionnaires on their satisfaction with the surgery, the subjective happiness scale (SHS) and the Pittsburgh Sleep Quality Index (PSQI) before and after surgery. The SHS increased postoperatively from 4.6 ± 0.7 to 4.8 ± 0.7 (P = 0.007) and 83.4% of patients were satisfied with the surgical results and the average satisfaction score was 4.2 out of a possible 5.0. Multiple regression analysis showed that patient satisfaction was significantly associated with the postoperative SHS (β = 0.380; P < 0.001), the postoperative PSQI (β = −0.041; P = 0.035) and the presence of a posterior subcapsular cataract (PSC) (β = 0.277; P = 0.026). This study clarified that cataract surgery may improve both visual function and patient happiness and that patient satisfaction was affected by postoperative sleep quality and the disappearance of a PSC.
ASJC Scopus subject areas


' Fertilizer CO2 – Shockwave CO2
SW FerCO2 is a low-cost fertilizer production system and clean CO2 source.
SW FerCO2 is a modified SW Chem Loop system that targets the impurities of natural gas flue gas and cleans the CO2. This system is a horizontal skid that operates as a semi-batch system and uses liquid chemical, either Na or K (Mg to be tested) to target SOx and NOx.
The liquid chemical cycles and mixes with the acid gases in the shockwave under a single contact until the appropriate pH is achieved and leaves the CO2 unreacted. The clean CO2 can then be piped directly into a greenhouse and the fertilizers can be used as a liquid spray to promote healthy and robust plant growth.
Let us help you choose the right shockwave system for you. CONTACT US


Truncation (InstanceTopic, 3)
From Hi.gher. Space
Truncation is the process of cutting polytope facets to produce new polytopes. The kind of truncation can be specified by a Dx number.
Classic truncations
The classic truncations have the first and nth nodes ringed, and have the same Dx number in each dimension. These are truncation (Dx 3) for n=2, cantellation (Dx 5) for n=3 and runcination (Dx 9) for n=4. The words can be concatenated (in reverse order of dimension) to count the various nodes that are ringed. For example, cantitruncation has the first, second and third nodes ringed and runcicantellation has the first, third and fourth nodes ringed.
Special truncations
There are three types of truncations which have a different Dx number in each dimension, while appearing to perform analogous operations on the actual polytope:
Truncates the polytope to its "midpoint". In odd dimensions, this is represented as the middle Coxeter-Dynkin node ringed. In even dimensions, the middle two nodes are ringed. Keiji had previously erroneously called this "rectification", however they are only the same in 3D: true rectification is represented with only the second node ringed, regardless of dimension.
"Expands" the polytope. This is represented with the first and last nodes ringed. Etymology: the Romanian for "outside" is "periferic" - you can imagine the ringed nodes as being on the "outside" (at the ends) of the diagram. Interestingly, peritruncating a polyhedron or polychoron is equivalent to mesotruncating it twice, but it is not yet known whether this extends to higher dimensions.
Gives the "largest", most "spherical" version of the root polytope, with the highest number of total elements. This is represented with all nodes ringed. Omnitruncating a polyhedron is equivalent to mesotruncating it and then 1-truncating the result, but it is not yet known whether this extends to higher dimensions.


The tooltip of the Mint says
0,007 mintEffect
But what does that mean?
Per Brilliand's answer in this question, Mints give a certain amount of furs and ivory per tick in exchange for a cost in gold and catpower.
The reason it doesn't just say "x.xx furs per second" or something like that is because the amount of furs and ivory gained is based on your maximum catpower, rather than being a particular amount. Thus, you get a certain amount of "mintEffect" which then translates through your maximum catpower and becomes ivory and furs. The linked question includes the exact amounts (and the points that mints become a more effective use of catpower than manual hunting, although you'll likely still be best served doing both).
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The Bridge as a Connection
Why were the
bridges built?
The Bridge as Machine
How did they
build the bridges?
The Bridge as Art
Why do the bridges
look like they do?
 People of the Bridge
Who designed
the bridges?
Tacoma Narrows Bridge Lesson Plans
Math/Technology/Science/Social Studies
Timeline - Curriculum Connections
Pacific Northwest History
The decision to build the Tacoma Narrows Bridge took a long time and deciding what type of bridge to build was a complicated process, due to the various bridge styles available and the costs associated with each. During the 1920s and 1930s a number of proposals were considered for building a bridge. In this lesson students will crate a timeline of proposals made for building a bridge across the Tacoma Narrows during the 1920s and 1930s. They will research the types of bridges proposed, and draw illustrations of them on the timeline. Students will also create a graph showing the estimated costs of each of the bridges proposed, and evaluate the merits of each proposal on the basis of what they learned.
Lesson Objectives
 1. Understand the complex special interest groups and political forces that led to building the Tacoma Narrows Bridge;
 2. Understand the competing forces at work planning any grand project of this nature;
 3. Explain the alternatives that were available for bridging the Narrows, and the costs of each;
 4. Compare and contrast the various alternatives proposed for the Narrows Bridge; and
 5. Evaluate the merits of each proposal for Bridging the Narrows.
Time: Three days or class periods, including one day of research, one day preparing timeline and graph, and one day to evaluate the proposals. The third day could also be used to discuss and share evaluations.
Materials Needed:
 - Internet access, graphing software such as PowerPoint or Excel, drawing paper, rulers, colored pencils.
Lesson Steps
1. Allow students to access the Tacoma Narrows Bridge website to find information for their timeline. After creating a rough draft, ask them to create their timeline on a large piece of drawing paper.
2. Next, have them research the various bridge types proposed and draw them on the timeline, using an appropriate scale.
3. While students are doing their research, they should also make a data table of the estimated costs of each proposal.
4. After completing their research, have students create a multi-colored graph showing the costs of each of the proposed bridges.
5. Ask students to evaluate various proposals and choose which they think was the best option for bridging the Narrows. Ask them to support their argument and be prepared to present it to the class orally.
6. After finishing their timelines, graphs and analysis, ask students to share their findings with the rest of the class. Discuss the merits of the various proposals and vote on the options. Which bridge would your class have chosen to build?
Related links on this site:
After the students have been working on their projects for a day or two, bring them together in a large group and ask them to help create a grading rubric. Ask them what attributes a top-quality timeline, graph or presentation might have, and list those attributes on an overhead projector or white board. Possibilities might include:
 - Information is complete and historically accurate;
 - Contains accurate and well-crafted drawings of bridges;
 - Graph is clear and colorful;
 - Arguments for building a particular bridge are well-supported;
 - Shows investment of time and effort;
 - Oral argument well presented.
Evaluate each attribute on an appropriate scale based on your own school's grading system, for example giving points or letter grades. Include student evaluations also, if desired.
 Copyright WSDOT © 2005


text:
Primary Education: The Key Concepts
By Denis Hayes
Published December 22nd 2005 by Routledge – 214 pages
Series: Routledge Key Guides
Presenting a balance of theoretical insight and practical advice, this text is a clear and accessible guide to the key issues relating to primary education. Alphabetically arranged and fully cross-referenced to ensure ease of use, entries include both curriculum specific terms, as well as those that are more generic, such as:
Written by an experienced teacher and lecturer, this is a concise yet comprehensive text that takes into account the everyday realities of teaching. Readable and user-friendly, it is a first-class resource for the primary practitioner at all levels.


Take the 2-minute tour ×
Two positive numbers $\alpha$ and $\beta$ are given. We are going to describe a process of choosing a random vector on the unit sphere $S$ in $\mathbb R^3$ (given by $x^2+y^2+z^2=1$).
A vector $u\in S$ is chosen uniformly at random in the spherical disc with center $(0,0,1)$ and radius $\alpha$ on the sphere. After that a vector $v\in S$ is chosen uniformly at random on the spherical circle with center $u$ and radius $\beta$.
Can we describe the distribution of $v$ on the sphere (e.g., by specifying its density function or otherwise)? Clearly, $v$ lies in the spherical disc around $(0,0,1)$ of radius $\alpha+\beta$, however its distribution doesn't seem to be uniform. Can we estimate somehow the most frequent angle that $v$ subtends with $(0,0,1)$? The answer should certainly depend on $\alpha$ and $\beta$.
(By a "spherical disc" with center $c$ and radius $r$ we understand the set of points on the sphere whose distance from $c$ is at most $r$. Similarly, a "spherical circle" with center $c$ and radius $r$ is the set of points on the sphere whose distance from $c$ is exactly $r$.)
This question arouse related to the distribution of the polarization vector in a randomly grained polycrystalline material (ceramics).
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I think you can get the answer as a one-dimensional integral using the spherical law of cosines. – Douglas Zare Sep 30 '12 at 20:44
Let $\theta$ be the angle the second radius $uv$ makes with the first radius $pv$ (where $p=(0,0,1)$) and let $\phi$ be the angle $v$ makes with $p$. Then the distribution of $v$ depends only on $\phi$, which in turn depends only on $\theta$, which is uniformly distributed. Calculate $\phi(\theta)$ and take $d\phi/d\theta$ and you have your answer. I get $\sqrt{1 - (\cot \alpha \cot \beta - \cos \phi \csc \alpha \csc \beta)^2} \csc \phi \sin \alpha \sin \beta$ in Mathematica, but I did not check this carefully. – Yoav Kallus Sep 30 '12 at 21:43
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Browse other questions tagged or ask your own question.


text:
How To: Configure the Spatiotemporal Big Data Store with the GeoEvent Extension
The Spatiotemporal Big Data Store is a special type of database used for storing feature service data, and is only available when using the ArcGIS Data Store product. It is used primarily with the GeoEvent Extension of ArcGIS Server starting at the 10.4 version, and can store and query many more data records than a traditional RDBMS.
Installing and configuring a Spatiotemporal Big Data Store implementation requires a minimum of three (3) server machines. This does not include any machines for redundancy and backup of the Spatiotemporal Big Data Store itself.
- The Web GIS Server (machine 1), consists of the following software: Portal for ArcGIS, ArcGIS Web Adaptor (IIIS), ArcGIS Data Store
- The Real Time Server (machine 2), consists of the following software: ArcGIS Server, ArcGIS GeoEvent Extension for Server
- The Big Data Server (machine 3) consists of the ArcGIS Data Store product configured as the Spatiotemporal Big Data Store
For data to be written to the Spatiotemporal Big Data Store, the software must be configured in a specific order:
- Install and configure the Portal for ArcGIS.
- Install and configure the ArcGIS Web Adaptor (IIS) to use with Portal for ArcGIS.
- Install and configure the ArcGIS Server.
- Install and configure the ArcGIS Data Store on machine 1 to be used by the ArcGIS Server. This should be the ArcGIS Server's Managed Geodatabase when viewed within ArcGIS Server Manager.
- Federate Portal for ArcGIS with ArcGIS Server, selecting the ArcGIS Server as the "Hosting Server".
- Install any Domain or other CA SSL certificates within the Portal for ArcGIS and ArcGIS Server key stores. If no SSL certificates are required, proceed to step 7.
- Install the ArcGIS GeoEvent Extension for Server. Verify that the default connection is set to "PORTAL".
- Install the ArcGIS Data Store on machine 3 (Big Data Server). Close the web page that pops up when the installation is complete.
- Within a command prompt on the machine, change the directory to C:\Program Files\ArcGIS\DataStore\tools. Run the "configuredatastore" file using the following parameters:
configuredatastore --stores spatiotemporal
- After the program executes with a success message, a new Spatiotemporal Big Data Store output can be created with the ArcGIS GeoEvent Extension.


text:
Pre-Kinder Combo Class #2 by Al Gilbert is a Pre-school or Kindergarten Class filled with activities to encourage creative expression. This class was created to be the perfect continuation in the introduction to Tap and Ballet.
Enhanced CD Includes:
- 26 fun tracks for your youngest students.
- Bonus - PDF files of notes, simply insert into your CD-ROM to view or print
- Bonus - iTunes files of each song. Drag and drop into your iTunes library


How to generate the point cloud classification
This process computes a point cloud classification using the densified point cloud that is generated during step 2.Point Cloud and Mesh. Each point is automatically classified in one of the following predefined groups:
 - Ground
 - Road Surface
 - High Vegetation
 - Building
 - Human Made Object
The point cloud classification can be performed:
During processing step 2. Point Cloud and Mesh
After processing step 2. Point Cloud and Mesh
In order to perform the point cloud classification while processing step 2. Point Cloud and Mesh:
 1. On the menu bar, click Process > Processing Options...
 2. Select the processing step 2. Point Cloud and Mesh.
 3. Select the tab Point Cloud.
 4. In the section Point Cloud Classification, select the box Classify Point Cloudclassify_process_options.jpg
 5. Click OK.
 6. Process step 2. Point Cloud and Mesh.
In order to perform the point cloud classification after processing step 2. Point Cloud and Mesh:
 1. On the menu bar, click Process > Run Point Cloud Classification.
Warning: When reprocessing step 2. Point Cloud and Mesh, the existing outputs and all edits will be deleted and overwritten.
The generated point groups can be visualized in the rayCloud and exported in several file formats:
Visualize the point cloud groups
Export the point cloud groups
Visualize the point cloud groups
The Point Groups layer has a Display Properties sub-layer that can be used to select the point groups to be displayed in the rayCloud. To visualize the point groups using the predefined classification colors the Show Class Color option should be enabled from the drop-down list. When the Show Class Color option is not enabled, the selected point groups are displayed with their original colors.
Note: Preselected colors are applied to the predefined point groups. User defined point groups are displayed as white points.
Export the point cloud groups
To export the point groups:
1. On the Menu bar, click View > rayCloud.
2. On the left sidebar, in the Layers section expand the Point Clouds list and right click on the densified point cloud's name to be exported.
3. Click Export Point Cloud...
4. In the Export Point Cloud pop-up that appears, select the point group to be exported.
5. Select the desired format between the following options: LAS, LAZ, PLY, XYZ.
Note: The classification labels are only exported for the LAS and LAZ file formats.
6. On Save As, type the desired file name.
Note: By default, the file is exported in the results folder with the same name as the original point cloud. To avoid overwriting the original point cloud, the name or the destination folder should be changed.
7. Click Browse... to navigate to the path where the point group is saved.
8. Click OK.
The point cloud classification is based on machine learning techniques which require training on labelled data. Both the geometry and the color information are used to assign the points of the densified point cloud in one of the predefined groups. The process performs well for environments similar to the ones of the datasets used for training the algorithm, such as rural, construction and vegetation areas. High vegetation and buildings are well-detected and classified. To learn more about the classification algorithm: Advanced knowledge - Scientific papers.
Depending on the quality of the dataset and the type of terrain, there are areas where the classification is not expected to perform perfectly and there is a need for manual intervention. Mountains, quarries and concrete buildings might need further editing. In the future, more training data will be used to improve the algorithm and give more reliable classification results for different types of projects.
Important: The classification algorithm performs better in projects with a GSD less than 5 cm.
It is possible to edit the point groups to improve the results of the classification. Points can be reallocated among point groups. The points that are erroneously assigned to a point group can be moved to the correct point group using the Edit Densified Point Cloud option: How to edit the point cloud in the rayCloud.
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Article feedback (for troubleshooting, post here)
 - yang li
 In my cloud point classification,I can get classification.
 i find error in ipx4d note,how to solve it?
 Error loading boosting model file C:/Users/李阳/AppData/Local/Temp/pix4d.P1XkOA/model.lightgbm
 [Error]: Could not load LightGBM model from file: C:/Users/李阳/AppData/Local/Temp/pix4d.P1XkOA/model.lightgbm
 [Error]: Error classifying pointcloud: Error classifying point cloud
 [Error]: Failed to run classification
 By the way,in other time,after run classification,my all points in pointGroups 'Unclassified'，What should i do if I want get right point cloud.
 - Blaž (Pix4D)
 Hi Yang,
 This issue is related to the project path.
 It seems that the 李阳 name in the path creates the problem. Could you please try to create another project using a different path that does not contain folders having special characters or spaces, such as 李阳?
 I expect the classification to work this way. If not, please let me know to further investigate the issue.
 - yang li
 Hi Blaž,
 Thanks,I have solved this problem.However, the results of point cloud classification are not ideal.If I use point cloud editing in the Raycloud, the workload will be huge. Can I export the original point cloud file of pix4d and try to use other software to classify it?
 Li yang
 - Blaž (Pix4D)
 It is possible to export the point cloud and classify it in a third party software. Then you can import external point clouds back into Pix4D and use them for the generation of your DSM, orthomosaic, and all other outputs that are generated in step 3. Read here to learn more about importing an external point cloud into Pix4D for processing.
 - James Scheideler
 Hi, what is the purpose of classifying the point cloud? My end goal is to generate contour lines that accurately represent my job site. When I classify the point cloud I notice that it tries to distinguish between man made and natural features among other things. Sometimes it is correct and other times it gets things wrong, but does it affect the contours? Is it worth fixing? What is the purpose of this? Thanks
 - Blaž (Pix4D)
 Keep in mind that the contour lines can be generated based on the DTM or DSM and in case that you want the contour lines to represent the "ground level", we recommend using the point cloud classification.
 The results of the point cloud classification are used for the DTM generation during step 3.DSM, Orthomosaic and Index.
 This means that the purpose of point cloud classification is to automatically assign points to predetermined groups. Out of these groups (Ground, Road Surface, High Vegetation, Building, Human Made Object), only the Ground and Road Surface groups are preserved in the DTM. To improve the DTM, all the terrain points should be assigned to one of these point groups. To manually move points between the automatically generated point groups, the Edit Densified Point Cloud option can be used: How to edit the point cloud in the rayCloud.
 - Aaron Meyer
 Thank you for the helpful videos and instructions. I have some questions regarding the processing the point cloud classification:
 The help article discusses the machine-learning to better classify the point clouds.
 1. Is this something that is learned by my computer as I reclassify points in the ray cloud?
 2. Is it possible to fine tune using pixel color? I have a lot of areas that are dirt (light brown) and it is classifying these points as roads (light grey).
 3. Is there a way to save the changes made to the classification of points? I had changed a lot of points, but then it was necessary (because of another issue) to re-run step 2 processing which removed all of the work done to the point cloud.
 - Blaž (Pix4D)
 Hi Arron, I am glad you were able to find information in the videos and instructions.
 As for the question:
 1. At the moment, the local reclassification is not used for learning the model and it will not influence further classifications.
 2. As mentioned in the Classification of aerial photogrammetric 3D point clouds scientific paper, our approach exploits both geometric and color information to classify individual points.
 3. The results of the classification will be lost when running Step 2. A workaround would be to export a classified point cloud prior to rerunning Step 2.
 - Corey Passlow
 Good Afternoon,
 Is it possible to create a Grid DSM of only the "Ground" and "Road" point classifications?
 - Blaž (Pix4D)
 Hi Corey,
 When generating Grid DSM all points are taken into account regardless of which point class they belong to.
 We find your need very relevant and will investigate further what could be done to cover the workflow you mention. We are