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Tag Archives: scientific integrity
Dr. R's comment on the Official Statement by the Board of the German Psychological Association (DGPs) about the Results of the OSF-Reproducibility Project published in Science.
October 10, 2015 UncategorizedDeutsche Gesellschaft für Psychologie, DGPs, Jacob Cohen, OSF-Reproducibility-Project, Post-Hoc-Power, Power, Publication Bias, Quality Control, Questionable Research Practices, Replicability Crisis, Replicability Index, scientific integrity, Statistical PowerUlrich Schimmack
Thanks to social media, geography is no longer a barrier for scientific discourse. However, language is still a barrier. Fortunately, I understand German and I can respond to the official statement of the board of the German Psychological Association (DGPs), which was posted on the DGPs website (in German).
On September 1, 2015, Prof. Dr. Andrea Abele-Brehm, Prof. Dr. Mario Gollwitzer, and Prof. Dr. Fritz Strack published an official response to the results of the OSF-Replication Project – Psychology (in German) that was distributed to public media in order to correct potentially negative impressions about psychology as a science.
Numerous members of DGPs felt that this official statement did not express their views and noticed that members were not consulted about the official response of their organization. In response to this criticism, DGfP opened a moderated discussion page, where members could post their personal views (mostly in German).
On October 6, 2015, the board closed the discussion page and posted some final words (Schlussbeitrag). In this blog, I provide a critical commentary on these final words.
BOARD'S RESPONSE TO COMMENTS
The board members provide a summary of the core insights and arguments of the discussion from their (personal/official) perspective.
"Wir möchten nun die aus unserer Sicht zentralen Erkenntnisse und Argumente der unterschiedlichen Forumsbeiträge im Folgenden zusammenfassen und deutlich machen, welche vorläufigen Erkenntnisse wir im Vorstand aus ihnen ziehen."
1. 68% success rate?
The first official statement suggested that the replication project showed that 68% of studies. This number is based on significance in a meta-analysis of the original and replication study. Critics pointed out that this approach is problematic because the replication project showed clearly that the original effect sizes were inflated (on average by 100%). Thus, the meta-analysis is biased and the 68% number is inflated.
In response to this criticism, the DGPs board states that "68% is the maximum [größtmöglich] optimistic estimate." I think the term "biased and statistically flawed estimate" is a more accurate description of this estimate. It is common practice to consider fail-safe-N or to correct meta-analysis for publication bias. When there is clear evidence of bias, it is unscientific to report the biased estimate. This would be like saying that the maximum optimistic estimate of global warming is that global warming does not exist. This is probably a true statement about the most optimistic estimate, but not a scientific estimate of the actual global warming that has been taking place. There is no place for optimism in science. Optimism is a bias and the aim of science is to remove bias. If DGPs wants to represent scientific psychology, the board should post what they consider the most accurate estimate of replicability in the OSF-project.
2. The widely cited 36% estimate is negative.
The board members then justify the publication of the maximally optimistic estimate as a strategy to counteract negative perceptions of psychology as a science in response to the finding that only 36% of results were replicated. The board members felt that these negative responses misrepresent the OSF-project and psychology as a scientific discipline.
"Dies wird weder dem Projekt der Open Science Collaboration noch unserer Disziplin insgesamt gerecht. Wir sollten jedoch bei der konstruktiven Bewältigung der Krise Vorreiter innerhalb der betroffenen Wissenschaften sein."
However, reporting the dismal 36% replication rate of the OSF-replication project is not a criticism of the OSF-project. Rather, it assumes that the OSF-replication project was a rigorous and successful attempt to provide an estimate of the typical replicability of results published in top psychology journals. The outcome could have been 70% or 35%. The quality of the project does not depend on the result. The result is also not a negatively biased perception of psychology as a science. It is an objective scientific estimate of the probability that a reported significant result in a journal would produce a significant result again in a replication study. Whether 36% is acceptable or not can be debated, but it seems problematic to post a maximally optimistic estimate to counteract negative implications of an objective estimate.
3. Is 36% replicability good or bad?
Next, the board ponders the implications of the 36% success rate. "How should we evaluate this number?" The board members do not know. According to their official conclusion, this question is complex as divergent contributions on the discussion page suggest.
"Im Science-Artikel wurde die relative Häufigkeit der in den Replikationsstudien statistisch bedeutsamen Effekte mit 36% angegeben. Wie ist diese Zahl zu bewerten? Wie komplex die Antwort auf diese Frage ist, machen die Forumsbeiträge von Roland Deutsch, Klaus Fiedler, Moritz Heene (s.a. Heene & Schimmack) und Frank Renkewitz deutlich."
To help the board members to understand the number, I can give a brief explanation of replicability. Although there are several ways to define replicability, one plausible definition of replicability is to equate it with statistical power. Statistical power is the probability that a study will produce a significant result. A study with 80% power has an 80% probability to produce a significant result. For a set of 100 studies, one would expect roughly 80 significant results and 20 non-significant results. For 100 studies with 36% power, one would expect roughly 36 significant results and 64 non-significant results. If researchers would publish all studies, the percentage of published significant results would provide an unbiased estimate of the typical power of studies. However, it is well known that significant results are more likely to be written up, submitted for publication, and accepted for publication. These reporting biases explain why psychology journals report over 90% significant results, although the actual power of studies is less than 90%.
In 1962, Jacob Cohen provided the first attempt to estimate replicability of psychological results. His analysis suggested that psychological studies have approximately 50% power. He suggested that psychologists should increase power to 80% to provide robust evidence for effects and to avoid wasting resources on studies that cannot detect small, but practically important effects. For the next 50 years, psychologists have ignored Cohen's warning that most studies are underpowered, despite repeated reminders that there are no signs of improvement, including reminders by prominent German psychologists like Gerg Giegerenzer, director of a Max Planck Institute (Sedlmeier & Giegerenzer, 1989; Maxwell, 2004; Schimmack, 2012).
The 36% success rate for an unbiased set of 100 replication studies, suggest that the actual power of published studies in psychology journals is 36%. The power of all studies conducted is even lower because the p < .05 selection criterion favors studies with higher power. Does the board think 36% power is an acceptable amount of power?
4. Psychologists should improve replicability in the future
On a positive note, the board members suggest that, after careful deliberation, psychologists need to improve replicability so that it can be demonstrated in a few years that replicability has increased.
"Wir müssen nach sorgfältiger Diskussion unter unseren Mitgliedern Maßnahmen ergreifen (bei Zeitschriften, in den Instituten, bei Förderorganisationen, etc.), die die Replikationsquote im temporalen Vergleich erhöhen können."
The board members do not mention a simple solution to the replicabilty problem that was advocated over 50 years ago by Jacob Cohen. To increase replicability, psychologists have to think about the strength of the effects that they are investigating and they have to conduct studies that have a realistic chance to distinguish these effects from variation due to random error. This often means investing more resources (larger samples, repeated trials, etc.) in a single study. Unfortunately, the leaders of German psychologists appear to be unaware of this important and simple solution to the replication crisis. They neither mention power as a cause of the problem, nor do they recommend increasing power to increase replicability in the future.
5. Do the Results Reveal Fraud?
The DGPs board members then discuss the possibility that the OSF-reproducibilty results reveal fraud, like the fraud committed by Stapel. The board points out that the OSF-results do not imply that psychologists commit fraud because failed replications can occur for various reasons.
"Viele Medien (und auch einige Kolleginnen und Kollegen aus unserem Fach) nennen die Befunde der Science-Studie im gleichen Atemzug mit den Betrugsskandalen, die unser Fach in den letzten Jahren erschüttert haben. Diese Assoziation ist unserer Meinung nach problematisch: sie suggeriert, die geringe Replikationsrate sei auf methodisch fragwürdiges Verhalten der Autor(inn)en der Originalstudien zurückzuführen."
It is true that the OSF-results do not reveal fraud. However, the board members confuse fraud with questionable research practices. Fraud is defined as fabricating data that were never collected. Only one of the 100 studies in the OSF-replication project (by Jens Förster, a former student of Fritz Strack, one of the board members) is currently being investigated for fraud by the University of Amsterdam. Despite very strong results in the original study, it failed to replicate.
The more relevant question is how much questionable research practices contributed to the results. Questionable research practices are practices where data are being collected, but statistical results are only being reported if they produce a significant result (studies, conditions, dependent variables, data points that do not produce significant results are excluded from the results that are being submitted for publication. It has been known for over 50 years that these practices produce a discrepancy between the actual power of studies and the rate of significant results that are published in psychology journals (Sterling, 1959).
Recent statistical developments have made it possible to estimate the true power of studies after correcting for publication bias. Based on these calculations, the true power of the original studies in the OSF-project was only 50%. Thus a large portion of the discrepancy between nearly 100% reported significant results and a replication success rate of 36% is explained by publication bias (see R-Index blogs for social psychology and cognitive psychology).
Other factors may contribute to the discrepancy between the statistical prediction that the replication success rate would be 50% and the actual success rate of 36%. Nevertheless, the lion share of the discrepancy can be explained by the questionable practice to report only evidence that supports a hypothesis that a researcher wants to support. This motivated bias undermines the very foundations of science. Unfortunately, the board ignores this implication of the OSF results.
6. What can we do?
The board members have no answer to this important question. In the past four years, numerous articles have been published that have made suggestions how psychology can improve its credibility as a science. Yet, the DPfP board seems to be unaware of these suggestions or unable to comment on these proposals.
"Damit wären wir bei der Frage, die uns als Fachgesellschaft am stärksten beschäftigt und weiter beschäftigen wird. Zum einen brauchen wir eine sorgfältige Selbstreflexion über die Bedeutung von Replikationen in unserem Fach, über die Bedeutung der neuesten Science-Studie sowie der weiteren, zurzeit noch im Druck oder in der Phase der Auswertung befindlichen Projekte des Center for Open Science (wie etwa die Many Labs-Studien) und über die Grenzen unserer Methoden und Paradigmen"
The time for more discussion has passed. After 50 years of ignoring Jacob Cohen's recommendation to increase statistical power it is time for action. If psychologists are serious about replicability, they have to increase the power of their studies.
The board then discusses the possibility of measuring and publishing replication rates at the level of departments or individual scientists. They are not in favor of such initiatives, but they provide no argument for their position.
"Datenbanken über erfolgreiche und gescheiterte Replikationen lassen sich natürlich auch auf der Ebene von Instituten oder sogar Personen auswerten (wer hat die höchste Replikationsrate, wer die niedrigste?). Sinnvoller als solche Auswertungen sind Initiativen, wie sie zurzeit (unter anderem) an der LMU an der LMU München implementiert wurden (siehe den Beitrag von Schönbrodt und Kollegen)."
The question is why replicability should not be measured and used to evaluate researchers. If the board really valued replicability and wanted to increase replicability in a few years, wouldn't it be helpful to have a measure of replicability and to reward departments or researchers who invest more resources in high powered studies that can produce significant results without the need to hide disconfirming evidence in file-drawers? A measure of replicability is also needed because current quantitative measures of scientific success are one of the reasons for the replicability crisis. The most successful researchers are those who publish the most significant results, no matter how these results were obtained (with the exception of fraud). To change this unscientific practice of significance chasing, it is necessary to have an alternative indicator of scientific quality that reflects how significant results were obtained.
The board makes some vague concluding remarks that are not worthwhile repeating here. So let me conclude with my own remarks.
The response of the DGPs board is superficial and does not engage with the actual arguments that were exchanged on the discussion page. Moreover, it ignores some solid scientific insights into the causes of the replicability crisis and it makes no concrete suggestions how German psychologists should change their behaviors to improve the credibility of psychology as a science. Not once do they point out that the results of the OSF-project were predictable based on the well-known fact that psychological studies are underpowered and that failed studies are hidden in file-drawers.
I received my education in Germany all the way to the Ph.D at the Free University in Berlin. I had several important professors and mentors that educated me about philosophy of science and research methods (Rainer Reisenzein, Hubert Feger, Hans Westmeyer, Wolfgang Schönpflug). I was a member of DGPs for many years. I do not believe that the opinion of the board members represent a general consensus among German psychologists. I hope that many German psychologists recognize the importance of replicability and are motivated to make changes to the way psychologists conduct research. As I am no longer a member of DGfP, I have no direct influence on it, but I hope that the next election will elect a candidate that will promote open science, transparency, and above all scientific integrity.
Questionable Research Practices: Definition, Detection, and Recommendations for Better Practices
January 24, 2015 r-index, R-Index4Science, sciencePower, QRP, Questionable Research Practices, r-index, replicability, Replication, research integrity, scientific integrity, Scientific MisconductUlrich Schimmack
The term "questionable research practices" (QRPs) was popularized in an article by John, Loewenstein, and Prelec (2012).
The authors distinguish between fraud and QRPs. Fraud is typically limited to cases in which researchers create false data. In contrast, QRPs typically involve the exclusion of data that are inconsistent with a theoretical hypothesis. QRPs are treated differently than fraud because QRPs can sometimes be used for legitimate purposes.
For example, a data entry error may produce a large outlier that leads to a non-significant result when all data are included in the analysis. The results are significant when the outlier is removed. Statistical textbook often advise to exclude outliers for this reason. However, removal of outliers becomes a QRP when it is used selectively. That is, outliers are not removed when a result is significant or when the outlier helps to produce a significant result, but outliers are removed when removal of outliers helps to get a significant result.
The use of QRPs is damaging because published results provide false impressions about the replicability of empirical results and misleading evidence about the size of an effect.
Below is a list of QRPs.
Selective reporting of (dependent) variables. For example, a researcher may include 10 items to measure depression. Typically, the 10 items are averaged to get the best measure of depression. However, if this analysis does not produce a significant result, the researcher can conduct analyses of each individual item or average items that trend in the right direction. By creating different dependent variables after the study is completed, a researcher increases the chances of obtaining a significant result that will not replicate in a replication study with the same dependent variable.
A simple solution to preventing this QRP is to ask authors to use well-established measures as dependent variables and/or to ask for pre-registration of all measures that are relevant to the test of a theoretical hypothesis (i.e., it is not necessary to specify that the study also asked about handedness because handedness is not a measure of depression).
Deciding whether to collect more data after looking to see whether the results will be significant. It is difficult to distinguish random variation from a true effect in small samples. At the same time, it can be a costly waste of resources (or even unethical in animal research) to conduct studies with large samples, when the effect can be detected in a smaller sample. It is also difficult to know a priori how large a sample should be to obtain a significant result. It therefore seems reasonable to check data while they are being collected for significance. If an effect does not seem to be present in a reasonably large sample size, it may be better to abandon a study. None of these practices are problematic unless a researcher constantly checks for significance and stops data collection immediately after the data show a significant result. This practice capitalizes on sampling error and the experiment will typically stop when sampling error inflates the true effect size.
A simple solution to this problem is to set some a priori rules about the end of data collection. For example, a researcher may calculate sample size based on a rough power analysis. Based on an optimistic assumption that the true effect is large, the data will be checked when the study has 80% power for a large effect (d = .8). If this does not result in a significant result, the researcher continues with the revised hypothesis that the true effect is moderate and then checks the data again when 80% power for a moderate effect is reached. If this does not result in a significant result, the researcher may give up or continue with the revised hypothesis that the true effect is small. This procedure would allow researchers to use an optimal amount of resources. Moreover, they can state there sampling strategy openly so that meta-analysts can make corrections for the small amount of biases that is still introduced by this reasonable form of optional stopping.
Failing to disclose experimental conditions. There are no justifiable reasons for the exclusion of conditions. Evidently, researchers are not going to exclude conditions that are consistent with theoretical predictions. So, the exclusion of conditions can only produce results that are overly consistent with theoretical predictions. If there are reasonable doubts about a condition (e.g., a manipulation check shows that it did not work), the condition can be included and it can be explained why the results may not conform to predictions).
A simple solution to the problem of conditions with unexpected results is that researchers may include too many conditions in their design. A 2 x 2 x 2 factorial design has 8 cells, which allows for 28 comparisons of means. What are the chances that all of these 28 comparisons produce results that are consistent with theoretical predictions?
Another simple solution is to avoid the use of statistical methods with low power. To demonstrate a three-way interaction requires a lot more data than to demonstrate that a pattern of means is consistent with an a priori theoretically predicted pattern.
In a paper reporting selectively studies that worked.
There is no reason for excluding studies that did not work. Excluding studies that were planned as demonstrations of an effect need to be reported. Otherwise the published evidence provides an overly positive picture of the robustness of a phenomenon and effect sizes are inflated.
Just like failed conditions, failed studies can be reported if there is a plausible explanation why it failed whereas other studies worked. However, to justify this claim, it should be demonstrated that the effects in failed and successful studies are really significantly different (a significant moderator effect). If this is not the case, there is no reason to treat failed and successful studies as different from each other.
A simple solution to this problem is to conduct studies with high statistical power because the main reason for failed studies is that studies have low power. If a study has only 30% power, only one out of three studies will produce a significant result. The other two studies are likely to produce a type-II error (not show a significant result when the effect exists). Rather than throwing away the two failed studies, a researcher should have conducted one study with higher power. Another solution is to report all three studies and to test for significance only in a meta-analysis across the three studies.
In a paper, rounding off a p-value just above .054 and claim that it is below .05. This is a minor problem. It is silly to change a p-value, but it does not bias a meta-analysis of effect sizes because researchers do not change effect size information. Moreover, it would be even more silly not to change the p-value and conclude that there is no effect, which is often the case when results are not significant. After all, a p-value of .054 means that the effect in this study would have occurred if the true effect is zero or has the opposite sign.
If a type-I error probability of 5.4% is considered too high, it would be possible to collect more data and test again with a larger sample (taking multiple testing into account).
Moreover, this problem should arise very infrequently. Even if a study is underpowered and has only 50% power, only 2% of p-values are expected to fall into the narrow range between .050 and .054.
In a paper, reporting an unexpected finding as having been predicted from the start. I am sure some statisticians disagree with me and I may be wrong about this one, but I simply do not understand how a statistical analysis of some data cares about the expectations of a researcher. Say, I analyze some data and find a significant effect in the data. How can this effect be influenced by the way I report it later? It may be a type-I error or it is not a type-I error, but my expectations have no influence on the causal processes that produced the empirical data. I think the practice of writing exploratory studies as if they were conducted an a priori hypothesis is considered questionable because it often requires other QRPs (e.g., excluding additional tests that didn't work) to produce a story that is concocted to explain unexpected results. However, if the results are presented honestly and one out of five predictor variables in a multiple-regression is significant at p < .0001, it is likely to be a replicable finding, even if it is presented with a post-hoc prediction.
In a paper, claiming that results are unaffected by demographic variables (e.g., gender) when one is actually unsure (or knows that they do). Again, this is a relatively minor point because it only speaks about potential moderators of a reported effect. Moderation is important, but the conclusion about the main effect remains unchanged. For example, if an effect exists for men, but not for women, it is still true that on average there is an effect. Furthermore, a more common mistake is often to claim that gender or other factors did not moderate an effect based on an underpowered comparison of 10 men and 30 women in a study with 40 participants. Thus, false claims about moderating variables are annoying, but not a threat to the replicability of empirical results.
Falsifying Data. I personally do not include falsifying or fabricating of data in the list of questionable research practices. I think falsifying and fabrication of data is not a research practice. It is also something that is clearly considered fraudulent and punished when it is discovered. In contrast, questionable research practices are tolerated in many scientific communities and there are no clear guidelines against the use of these practices.
In conclusion, the most problematic research practices that undermine the replicability of published studies are selective reporting of dependent variables, conditions, or entire studies, and optional stopping when significance is reached. These practices make it possible to produce significant results when a study has insufficient power. However, to achieve significance without power, the type-I error rate also increases and replicability decreases. John et al. (2012) aptly compared these QRPs to the use of doping in sports. I consider the R-Index a doping test for science because it reveals that researchers used these QRPs. I hope that the R-Index will discourage the use of QRPs and increase the power and replicability of published studies.
Whether scientific organizations should ban QRPs just like sports organizations ban doping is an interesting question. Meanwhile the R-Index can be used without draconian consequences. Researchers can self-examine the replicability of their findings and they can examine the replicability of published results before they invest resources, time, and the future of their graduate students in research projects that fail. Granting agencies can use the R-Index to reward researchers who conduct fewer studies with replicable results rather than researchers with many studies that fail to replicate. Finally, the R-Index can be used to track how successful current initiatives are to increase the replicability of published studies.
How Power Analysis Could Have Prevented the Sad Story of Dr. Förster
January 2, 2015 r-index, R-Index4Science, scienceJens Forster, LOWI, QRP, Questionable Research Practices, r-index, replicability, Reporting Bias, research integrity, Research Misconduct, Retraction, scientific integrity, Scientific Misconduct, Social Psychology, TIVAUlrich Schimmack
[further information can be found in a follow up blog]
In 2011, Dr. Förster published an article in Journal of Experimental Psychology: General. The article reported 12 studies and each study reported several hypothesis tests. The abstract reports that "In all experiments, global/local processing in 1 modality shifted to global/local processing in the other modality".
For a while this article was just another article that reported a large number of studies that all worked and neither reviewers nor the editor who accepted the manuscript for publication found anything wrong with the reported results.
In 2012, an anonymous letter voiced suspicion that Jens Forster violated rules of scientific misconduct. The allegation led to an investigation, but as of today (January 1, 2015) there is no satisfactory account of what happened. Jens Förster maintains that he is innocent (5b. Brief von Jens Förster vom 10. September 2014) and blames the accusations about scientific misconduct on a climate of hypervigilance after the discovery of scientific misconduct by another social psychologist.
The Accusation
The accusation is based on an unusual statistical pattern in three publications. The 3 articles reported 40 experiments with 2284 participants, that is an average sample size of N = 57 participants in each experiment. The 40 experiments all had a between-subject design with three groups: one group received a manipulation design to increase scores on the dependent variable. A second group received the opposite manipulation to decrease scores on the dependent variable. And a third group served as a control condition with the expectation that the average of the group would fall in the middle of the two other groups. To demonstrate that both manipulations have an effect, both experimental groups have to show significant differences from the control group.
The accuser noticed that the reported means were unusually close to a linear trend. This means that the two experimental conditions showed markedly symmetrical deviations from the control group. For example, if one manipulation increased scores on the dependent variables by half a standard deviation (d = +.5), the other manipulation decreased scores on the dependent variable by half a standard deviation (d = -.5). Such a symmetrical pattern can be expected when the two manipulations are equally strong AND WHEN SAMPLE SIZES ARE LARGE ENOUGH TO MINIMIZE RANDOM SAMPLING ERROR. However, the sample sizes were small (n = 20 per condition, N = 60 per study). These sample sizes are not unusual and social psychologists often use n = 20 per condition to plan studies. However, these sample sizes have low power to produce consistent results across a large number of studies.
The accuser computed the statistical probability of obtaining the reported linear trend. The probability of obtaining the picture-perfect pattern of means by chance alone was incredibly small.
Based on this finding, the Dutch National Board for Research Integrity (LOWI) started an investigation of the causes for this unlikely finding. An English translation of the final report was published on retraction watch. An important question was whether the reported results could have been obtained by means of questionable research practices or whether the statistical pattern can only be explained by data manipulation. The English translation of the final report includes two relevant passages.
According to one statistical expert "QRP cannot be excluded, which in the opinion of the expert is a common, if not "prevalent" practice, in this field of science." This would mean that Dr. Förster acted in accordance with scientific practices and that his behavior would not constitute scientific misconduct.
In response to this assessment the Complainant "extensively counters the expert's claim that the unlikely patterns in the experiments can be explained by QRP." This led to the decision that scientific misconduct occurred.
Four QRPs were considered.
Improper rounding of p-values. This QRP can only be used rarely when p-values happen to be close to .05. It is correct that this QRP cannot produce highly unusual patterns in a series of replication studies. It can also be easily checked by computing exact p-values from reported test statistics.
Selecting dependent variables from a set of dependent variables. The articles in question reported several experiments that used the same dependent variable. Thus, this QRP cannot explain the unusual pattern in the data.
Collecting additional research data after an initial research finding revealed a non-significant result. This description of an QRP is ambiguous. Presumably it refers to optional stopping. That is, when the data trend in the right direction to continue data collection with repeated checking of p-values and stopping when the p-value is significant. This practices lead to random variation in sample sizes. However, studies in the reported articles all have more or less 20 participants per condition. Thus, optional stopping can be ruled out. However, if a condition with 20 participants does not produce a significant result, it could simply be discarded, and another condition with 20 participants could be run. With a false-positive rate of 5%, this procedure will eventually yield the desired outcome while holding sample size constant. It seems implausible that Dr. Förster conducted 20 studies to obtain a single significant result. Thus, it is even more plausible that the effect is actually there, but that studies with n = 20 per condition have low power. If power were just 30%, the effect would appear in every third study significantly, and only 60 participants were used to produce significant results in one out of three studies. The report provides insufficient information to rule out this QRP, although it is well-known that excluding failed studies is a common practice in all sciences.
Selectively and secretly deleting data of participants (i.e., outliers) to arrive at significant results. The report provides no explanation how this QRP can be ruled out as an explanation. Simmons, Nelson, and Simonsohn (2011) demonstrated that conducting a study with 37 participants and then deleting data from 17 participants can contribute to a significant result when the null-hypothesis is true. However, if an actual effect is present, fewer participants need to be deleted to obtain a significant result. If the original sample size is large enough, it is always possible to delete cases to end up with a significant result. Of course, at some point selective and secretive deletion of observation is just data fabrication. Rather than making up data, actual data from participants are deleted to end up with the desired pattern of results. However, without information about the true effect size, it is difficult to determine whether an effect was present and just embellished (see Fisher's analysis of Mendel's famous genetics studies) or whether the null-hypothesis is true.
The English translation of the report does not contain any statements about questionable research practices from Dr. Förster. In an email communication on January 2, 2014, Dr. Förster revealed that he in fact ran multiple studies, some of which did not produce significant results, and that he only reported his best studies. He also mentioned that he openly admitted to this common practice to the commission. The English translation of the final report does not mention this fact. Thus, it remains an open question whether QRPs could have produced the unusual linearity in Dr. Förster's studies.
A New Perspective: The Curse of Low Powered Studies
One unresolved question is why Dr. Förster would manipulate data to produce a linear pattern of means that he did not even mention in his articles. (Discover magazine).
One plausible answer is that the linear pattern is the by-product of questionable research practices to claim that two experimental groups with opposite manipulations are both significantly different from a control group. To support this claim, the articles always report contrasts of the experimental conditions and the control condition (see Table below).
In Table 1 the results of these critical tests are reported with subscripts next to the reported means. As the direction of the effect is theoretically determined, a one-tailed test was used. The null-hypothesis was rejected when p < .05.
Table 1 reports 9 comparisons of global processing conditions and control groups and 9 comparisons of local processing conditions with a control group; a total of 18 critical significance tests. All studies had approximately 20 participants per condition. The average effect size across the 18 studies is d = .71 (median d = .68). An a priori power analysis with d = .7, N = 40, and significance criterion .05 (one-tailed) gives a power estimate of 69%.
An alternative approach is to compute observed power for each study and to use median observed power (MOP) as an estimate of true power. This approach is more appropriate when effect sizes vary across studies. In this case, it leads to the same conclusion, MOP = 67.
The MOP estimate of power implies that a set of 100 tests is expected to produce 67 significant results and 33 non-significant results. For a set of 18 tests, the expected values are 12.4 significant results and 5.6 non-significant results.
The actual success rate in Table 1 should be easy to infer from Table 1, but there are some inaccuracies in the subscripts. For example, Study 1a shows no significant difference between means of 38 and 31 (d = .60, but it shows a significant difference between means 31 and 27 (d = .33). Most likely the subscript for the control condition should be c not a.
Based on the reported means and standard deviations, the actual success rate with N = 40 and p < .05 (one-tailed) is 83% (15 significant and 3 non-significant results).
The actual success rate (83%) is higher than one would expect based on MOP (67%). This inflation in the success rate suggests that the reported results are biased in favor of significant results (the reasons for this bias are irrelevant for the following discussion, but it could be produced by not reporting studies with non-significant results, which would be consistent with Dr. Förster's account ).
The R-Index was developed to correct for this bias. The R-Index subtracts the inflation rate (83% – 67% = 16%) from MOP. For the data in Table 1, the R-Index is 51% (67% – 16%).
Given the use of a between-subject design and approximately equal sample sizes in all studies, the inflation in power can be used to estimate inflation of effect sizes. A study with N = 40 and p < .05 (one-tailed) has 50% power when d = .50.
Thus, one interpretation of the results in Table 1 is that the true effect sizes of the manipulation is d = .5, that 9 out of 18 tests should have produced a significant contrast at p < .05 (one-tailed) and that questionable research practices were used to increase the success rate from 50% to 83% (15 vs. 9 successes).
The use of questionable research practices would also explain unusual linearity in the data. Questionable research practices will increase or omit effect sizes that are insufficient to produce a significant result. With a sample size of N = 40, an effect size of d = .5 is insufficient to produce a significant result, d = .5, se = 32, t(38) = 1.58, p = .06 (one-tailed). Random sampling error that works against the hypothesis can only produce non-significant results that have to be dropped or moved upwards using questionable methods. Random error that favors the hypothesis will inflate the effect size and start producing significant results. However, random error is normally distributed around the true effect size and is more likely to produce results that are just significant (d = .8) than to produce results that are very significant (d = 1.5). Thus, the reported effect sizes will be clustered more closely around the median inflated effect size than one would expect based on an unbiased sample of effect sizes.
The clustering of effect sizes will happen for the positive effects in the global processing condition and for the negative effects in the local processing condition. As a result, the pattern of all three means will be more linear than an unbiased set of studies would predict. In a large set of studies, this bias will produce a very low p-value.
One way to test this hypothesis is to examine the variability in the reported results. The Test of Insufficient Variance (TIVA) was developed for this purpose. TIVA first converts p-values into z-scores. The variance of z-scores is known to be 1. Thus, a representative sample of z-scores should have a variance of 1, but questionable research practices lead to a reduction in variance. The probability that a set of z-scores is a representative set of z-scores can be computed with a chi-square test and chi-square is a function of the ratio of the expected and observed variance and the number of studies. For the set of studies in Table 1, the variance in z-scores is .33. The chi-square value is 54. With 17 degrees of freedom, the p-value is 0.00000917 and the odds of this event occurring by chance are 1 out of 109,056 times.
Previous discussions about abnormal linearity in Dr. Förster's studies have failed to provide a satisfactory answer. An anonymous accuser claimed that the data were fabricated or manipulated, which the author vehemently denies. This blog proposes a plausible explanation of what could have [edited January 19, 2015] happened. Dr. Förster may have conducted more studies than were reported and included only studies with significant results in his articles. Slight variation in sample sizes suggests that he may also have removed a few outliers selectively to compensate for low power. Importantly, neither of these practices would imply scientific misconduct. The conclusion of the commission that scientific misconduct occurred rests on the assumption that QRPs cannot explain the unusual linearity of means, but this blog points out how selective reporting of positive results may have inadvertently produced this linear pattern of means. Thus, the present analysis support the conclusion by an independent statistical expert mentioned in the LOWI report: "QRP cannot be excluded, which in the opinion of the expert is a common, if not "prevalent" practice, in this field of science."
How Unusual is an R-Index of 51?
The R-Index for the 18 statistical tests reported in Table 1 is 51% and TIVA confirms that the reported p-values have insufficient variance. Thus, it is highly probable that questionable research practices contributed to the results and in a personal communication Dr. Förster confirmed that additional studies with non-significant results exist. However, in response to further inquiries [see follow up blog] Dr. Förster denied having used QRPs that could explain the linearity in his data.
Nevertheless, an R-Index of 51% is not unusual and has been explained with the use of QRPs. For example, the R-Index for a set of studies by Roy Baumeister was 49%, . and Roy Baumeister stated that QRPs were used to obtain significant results.
"We did run multiple studies, some of which did not work, and some of which worked better than others. You may think that not reporting the less successful studies is wrong, but that is how the field works."
Sadly, it is quite common to find an R-Index of 50% or lower for prominent publications in social psychology. This is not surprising because questionable research practices were considered good practices until recently. Even at present, it is not clear whether these practices constitute scientific misconduct (see discussion in Dialogue, Newsletter of the Society for Personality and Social Psychology).
How to Avoid Similar Sad Stories in the Future
One way to avoid accusations of scientific misconduct is to conduct a priori power analyses and to conduct only studies with a realistic chance to produce a significant result when the hypothesis is correct. When random error is small, true patterns in data can emerge without the help of QRPs.
Another important lesson from this story is to reduce the number of statistical tests as much as possible. Table 1 reported 18 statistical tests with the aim to demonstrate significance in each test. Even with a liberal criterion of .1 (one-tailed), it is highly unlikely that so many significant tests will produce positive results. Thus, a non-significant result is likely to emerge and researchers should think ahead of time how they would deal with non-significant results.
For the data in Table 1, Dr. Förster could have reported the means of 9 small studies without significance tests and conduct significance tests only once for the pattern in all 9 studies. With a total sample size of 360 participants (9 * 40), this test would have 90% power even if the effect size is only d = .35. With 90% power, the total power to obtain significant differences from the control condition for both manipulations would be 81%. Thus, the same amount of resources that were used for the controversial findings could have been used to conduct a powerful empirical test of theoretical predictions without the need to hide inconclusive, non-significant results in studies with low power.
Jacob Cohen has been trying to teach psychologists the importance of statistical power for decades and psychologists stubbornly ignored his valuable contribution to research methodology until he died in 1998. Methodologists have been mystified by the refusal of psychologists to increase power in their studies (Maxwell, 2004).
One explanation is that small samples provided a huge incentive. A non-significant result can be discarded with little cost of resources, whereas a significant result can be published and have the additional benefit of an inflated effect size, which allows boosting the importance of published results.
The R-Index was developed to balance the incentive structure towards studies with high power. A low R-Index reveals that a researcher is reporting biased results that will be difficult to replicate by other researchers. The R-Index reveals this inconvenient truth and lowers excitement about incredible results that are indeed incredible. The R-Index can also be used by researchers to control their own excitement about results that are mostly due to sampling error and to curb the excitement of eager research assistants that may be motivated to bias results to please a professor.
Curbed excitement does not mean that the R-Index makes science less exciting. Indeed, it will be exciting when social psychologists start reporting credible results about social behavior that boost a high R-Index because for a true scientist nothing is more exciting than the truth.
The Replicability-Index (R-Index): Quantifying Research Integrity
December 1, 2014 Post-Hoc Power, r-index, R-Index4Science, Replicability, Research Integrity, scienceForensic Statistics, Questionable Research Practices, research integrity, scientific integrity, Scientific MisonductUlrich Schimmack
ANNIVERSARY POST. Slightly edited version of first R-Index Blog on December 1, 2014.
In a now infamous article, Bem (2011) produced 9 (out of 10) statistically significant results that appeared to show time-reversed causality. Not surprisingly, subsequent studies failed to replicate this finding. Although Bem never admitted it, it is likely that he used questionable research practices to produce his results. That is, he did not just run 10 studies and found 9 significant results. He may have dropped failed studies, deleted outliers, etc. It is well-known among scientists (but not lay people) that researchers routinely use these questionable practices to produce results that advance their careers. Think, doping for scientists.
I have developed a statistical index that tracks whether published results were obtained by conducting a series of studies with a good chance of producing a positive result (high statistical power) or whether researchers used questionable research practices. The R-Index is a function of the observed power in a set of studies. More power means that results are likely to replicate in a replication attempt. The second component of the R-index is the discrepancy between observed power and the rate of significant results. 100 studies with 80% power should produce, on average, 80% significant results. If observed power is 80% and the success rate is 100%, questionable research practices were used to obtain more significant results than the data justify. In this case, the actual power is less than 80% because questionable research practices inflate observed power. The R-index subtracts the discrepancy (in this case 20% too many significant results) from observed power to adjust for the inflation. For example, if observed power is 80% and success rate is 100%, the discrepancy is 20% and the R-index is 60%.
In a paper, I show that the R-index predicts success in empirical replication studies.
The R-index also sheds light on the recent controversy about failed replications in psychology (repligate) between replicators and "replihaters." Replicators sometimes imply that failed replications are to be expected because original studies used small samples with surprisingly large effects, possibly due to the use of questionable research practices. Replihaters counter that replicators are incompetent researchers who are motivated to produce failed studies. The R-Index makes it possible to evaluate these claims objectively and scientifically. It shows that the rampant use of questionable research practices in original studies makes it extremely likely that replication studies will fail. Replihaters should take note that questionable research practices can be detected and that many failed replications are predicted by low statistical power in original articles.


Save the date Sunday, December 15th, 2019, and join us for a fun-filled afternoon this coming Holiday Season!
Children's Cancer Research Fund WAS thrilled to present a very special Holiday treat for you, children with cancer and their families - "HOLIDAY ON ICE" at L.A. LIVE on Sunday, December 9th. Thank you for joining us for a fun-filled afternoon of smiles and holiday cheer for all!
On behalf of the doctors, children and their families and Children's Cancer Research Fund, THANK YOU for all the SMILES that DID make this Holiday Celebration Special!
Speaking of KIDS 4 KIDS, our friend Ashley has created this new endeavor.
Helping kids one stitch at a time!
Ashley is creating knitted items and selling them at Gifts of the Season and Etsy.
Profits will benefit Children's Cancer Research Fund.
These Smiles...What Are They Worth?
What is a child's smile worth? Especially the smile of a seriously ill child undergoing difficult treatments in a strange place, maybe far from home.
Caring people - like yourself - and Children's Cancer Research Fund (CCRF) know how valuable and important smiles can be at such a time.
Established in 1987, CCRF is dedicated to providing national support for clinical research in pediatric cancer, while improving the medical environment for all children. A Healthier and Happier tomorrow is the mission and promise of a Children's Cancer Research Fund to children and their parents everywhere.
CCRF 2019 | Website maintained by Campaign.


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The Review made 83 recommendations. These were sorted into work programs for implementation.
Youth detention centres are monitored and reviewed to ensure young people are safe and receive quality services and support. The organisations that do this are called oversight agencies. Our oversight agencies include:
Youth Detention Inspectorate
Office of the Queensland Ombudsman.
Youth Justice also performs internal oversight and review to:
identify service improvements that are needed
drive continuous improvement to practice.
Oversight of youth detention centres will be:
independent.
Oversight activities and recommendations will ensure our services grow with contemporary best practice.
To achieve this we will:
have an independent, expert agency make a thorough and robust evaluation of oversight options
work with oversight agencies to put in place an effective and efficient model with statutory independence.
Recommendation 15 (status: complete)
The Review recommends that the Queensland Government replace the Youth Detention Inspectorate (ESU) and Office of the Chief Inspector (QCS) with an independent statutory Office of the Inspector of Custodial Services in a similar form to that of Western Australia. (8.R1)
The Queensland Government supports the establishment of a new independent Office of the Inspector of Custodial Services.
We must ensure that the new office has a strong and discrete focus on the needs of young people in youth detention centres and that inspection expectations align with youth justice philosophies, legislative frameworks and service standards.
The Queensland Family and Child Commission, a statutory, child-focussed agency with independence from the youth justice system, prepared an options paper. We received the report on 21 March 2018 and are working with Queensland Corrective Services, Department of Justice and Attorney-General and the Department of Premier and Cabinet to progress it.
Requirements of the Optional Protocol to the Convention against Torture are also being considered as part of this work.
The Review recommends that the key features of the Queensland Inspector of Custodial Services should include:
transparency; and
accountability. (8.R2)
See response to recommendation 15.

redpajama_set_name: RedPajamaCommonCrawl


With no cut or a very small cut, prices to remain where they are with chances of downside, says Ahmad.
The market is getting a little bit nervous because all options are on the table and anything could happen during the Opec meeting with Russia today. Azlin Ahmad, Editor, Crude Oil, Argus Media, tells ET Now. There is an issue with demand. But the problem right now with the oil prices is the supply, says Ahmad.
Are there hopes of output cut still on the table?
Oh yes, I think there is. It is alright now. It was a little bit uncertain because before the OPEC meeting started, the market was quite confident that there would be a cut of at least below a million barrels per day. The market is still hoping for a bigger cut. But the Saudi oil minister also has not ruled out the possibility that there may not be any deal soon right now. With no announcement from the first day of talks, the market is getting a little bit nervous because all options are on the table and anything could happen during the meeting today. But the market is still holding out for a cut of about a million barrels per day.
Crude has declined almost 3% and it is now sub-60. Could we see the prices spiral upwards and if so, what is the range you are looking at?
The anticipation was that there would be some sort of announcement from the Saudi oil minister and from the OPEC members after the first day. The market was holding out for that and when that did not happen, it just spooked the market a little bit and the oil prices dropped quite sharply. But if OPEC does cut output by a million barrels per day, we will see prices recover. It will not be a huge increase because the market feels that one million barrels per day is more or less on the lower end of what is needed to balance out the market to take out the oversupply. SIf OPEC does somehow decide to cut a much larger amount than one million barrel per day, then the prices could jump higher. But with no cut or a very small cut, prices could remain where they are with a lot of chances on the downside.
Where does demand fit in? We tend to focus a lot on what Trump is tweeting, what OPEC is doing. Ultimately the crude price is a function of demand. What are the demand trends indicating?
Well at the moment, the weakness in the market is because of oversupply rather than demand. As you can see, Russia has been producing record high levels and so has Saudi Arabia. US production has been rising. If you look at the production levels over the last six months, basically the falling oil prices is all due to an oversupply and also because it looks like the Iran export cuts is not going to be as drastic as the market expected.
Demand has been very steady. I do not think demand has crashed. There were lots of concerns that the trade war between the US-China would have quite a bit big impact on demand especially in the first quarter in 2019 but with the current truce in trade war, one would be more optimistic. I do not think that there is an issue with demand. But the problem right now with the oil prices is the supply.


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Baltimore high school sports portal (Feb. 12): No. 1 Boys' Latin upended by Pallotti in boys basketball
This week's wintry weather has forced changes in the Interscholastic Athletic Association of Maryland's basketball tournament.
The quarterfinals for the A, B and C Conferences were all scheduled for Tuesday with the semifinals Thursday and the championship games for Sunday. Now, the quarterfinals will be played on Wednesday with the semifinals on Friday in all three conferences.
The championship games, meanwhile, are still scheduled for Sunday at Stevenson at 2 p.m., 4 p.m. and 6 p.m. (for the C, B and A Conferences, respectively).
So far, there were first-round games in the B and C Conference, which set up the quarterfinals. There were none of those in the A Conference as just eight teams are in it, and the first round is the quarterfinal.
High School Sports videos
Latest High School sports
Carroll County High School Sports
What to watch this week in Carroll County Athletic League winter sports
2021 Carroll County Athletic League winter sports schedule, results
Astros pitcher Peter Solomon looking to 'carry on the tradition' of major leaguers from Mount Saint Joseph


Were You Arrested for Being "Drunk in Public"?
2) Due to his or her level of intoxication, the person "interferes with or obstructs or prevents the free use of any street, sidewalk, or other public way.
A conviction for a drunk in public carries with it up to six months of jail time, and/or a fine of up to one thousand dollars and probation. Even if the judge sentences you only to probation rather than jail time a "drunk in public" conviction will still go on your permanent criminal record, where it can be seen by prospective employers and licensing agencies.
If you are convicted of "drunk in public" three (3) times within a twelve (12)-month period, you face a minimum of ninety (90) days in county jail. The court can suspend this penalty requirement if you spend sixty (60) days in an alcohol treatment and recovery program.
If you were arrested in a home, hotel room or other private place, there was no "public intoxication"…regardless of how drunk you may have been.
In order for you to be guilty of California drunk in public, prosecutors need to be able to show beyond a reasonable doubt both that you were willfully intoxicated in a public place and that you engaged in behavior that meets the legal definition of public intoxication.
If you have questions about California's "drunk in public" law, or you would like to discuss your case confidentially, we invite you to contact us.


Never work a goal without a plan. Your plan should be simple and honest. Never plan below what you desire to truly achieve. Once you have your goal then create your plan on how you will go about achieving this goal.
Decide on a hair care regimen that will help you achieve your length goals. When choosing a regimen consider your present lifestyle and how much time you will need to set aside for this plan. A good hair care regimen covers 3 areas well, moisture, stimulation and protection. The Coily Queens Regimen covers these three areas very well. The CQR helps you achieve your hair length goals the fastest. Your hair will grow long and healthy with dedication to the CQR.
Always have a written plan and records of your daily achievements. Write your goals out so you can see them. Know your starting length so you can track your progress. Progress fuels your motivation.
A double minded person never achieves much of anything. Once you commit to a hair care regimen stay loyal to it, as long as it is working. It usually takes months to see big results from any hair regimen. Certainly when you are going for long lengths it take 3 to 6 months to see length accumulation. To many people switch regimens simply because something else sounds good. That is an premature move. Stay loyal to your decision.
Yes you can grow your hair without using fake hair. If you want to use fake hair that is an option for you but it is not a requirement. Enjoy your hair. We are always more successful when we are happy. Rocking your own hair makes you happy. Create a style plan. Designate specific days to let your hair down and enjoy the fruits of your labor.
Once you decide on a hair care regimen, it is good to take a break from hair forums, hair groups and website. Take a break so you are not distracted from other regimens which sound good and tempt you to try them instead of the one you have decided on. Having to many choices many times makes you doubt your first choice. Make a decision, have faith in your choice and work your regimen.
When you reach your goal sit back, cruise and maintain your length.
Maintain your length by following a good hair care regimen such as the Coily Queens Regimen. You will not retain length without a good hair care regimen. Sometimes the retaining can be more difficult than the growing. Have fun and enjoy your hair. But practice correct styling methods and product usage. The Coily Queens Regimen gives you all the information you need on buying the right products and minimizing breakage. Start it today. Click the link up top for the full Coily Queens Method.
long term and short term goals. Once you have reached your goal, create a new one.Set a plan to maintain your length, do not abandon your regimen just because you have attained your goal.


Want To Upsell Your Pegasus Opera Clients?
Interlockdigital are looking for a small number of Strategic and Premier Pegasus Partners across the UK to assist in deploying our proven Opera Web Store solution.
If you have a solid base of Opera customers and are looking for ways to generate extra revenue from them, then helping them create an integrated online store presence plugged directly into Opera could be the solution you need.
We understand that you've worked hard to earn the trust of your Opera clients, and need to safe-guard these relationships.
Our role from the outset with any Opera Web Store project is clearly scoped to cover the online and web-integration components of the solution. This creates a clear division of responsibility leaving you as Pegasus Partner in control of the Opera solution, which remains at the heart of the customer business.


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National Metal and Steel Corporation est une entreprise de ferraillage engagée dans des opérations de démantèlement de navires à Terminal Island dans la région du port de Los Angeles de la ville de Los Angeles, en Californie.

Le président de National Metal and Steel était Harry Faversham.

Histoire
National Metal and Steel était la destination finale de nombreux navires déclassés de la marine américaine (US Navy).

En 1953, elle a été la première entreprise américaine à exporter de la ferraille vers le Japon d'après-guerre.

Elle a assuré la démolition de nombreux wagons rouges de la Pacific Electric Railway et de wagons jaunes de la Los Angeles Railway à la suite de la suppression de ces systèmes de transport public dans la région de Los Angeles (Greater Los Angeles Area).

Un certain nombre de locomotives articulées AC-9, très lourdes et alimentées au charbon, de la Southern Pacific, ont également été démolies ici. Pour des raisons opérationnelles, ces locomotives n'étaient utilisables qu'au Nouveau-Mexique et au Texas, et n'étaient que très rarement exploitées ailleurs sur le réseau de la Southern Pacific pour des raisons de dégagement.

Les opérations sur Terminal Island ont cessé le 1 janvier 1986 lorsque la société a perdu cette installation au profit d'un projet d'expansion du port. National Metal and Steel a maintenu son siège dans la ville voisine de Carson.

Références

Source

Démolition navale
Carson (Californie)
Terminal Island

redpajama_set_name: RedPajamaWikipedia


With a good stock screener tool, the days of doing due diligence checks manually by value investors are over.
A good stock screener helps value investors to filter off stocks that are not matching their value investing criteria. Finding what stocks to buy in Singapore or in any other stock market is not an easy task. Why? The list of listed companies is getting longer and the information available online is overwhelming. There are tons of endless corporate announcements and online resources for investors to digest before the right information can be put into good use.
Many investors lose money because they spend time in listening to rumors, analyst news and friends. Emotion and greed are the two major causes of making a mistake in stock investing. And often, the mistakes made can be deadly to some. On the other hand, good investors spend time to analyse the available data and they do due diligence check to confirm if a stock is worthwhile to buy.
Doing due diligence check is a must for value investors. Today, there are still quite many value investors are still using spreadsheets to work out on the financial ratios. This is not productive. If you are serious in value investing, you need have a good stock searching tool to help you out.
I have personally tried a few of them before such as those which are offered by SGX, Yahoo Finance, Finviz and Uncle Stock. These are generally cool and easy to use tools.
These tools are a great resource when searching for undervalued stocks, growth stocks, dividend stocks or defensive stocks. They help to save up your time to do the due diligence check manually at a click of a button. This will make you life as a value investor for easier. If you are not using one today, consider one today.
Check out how you can leverage on system tools like the above to help you out in your value investing journey by signing up our free full day 4 hours Technology Assisted Stock Hacking Workshop Singapore here.


6851 Sharon Court has a Walk Score of 29 out of 100. This location is a Car-Dependent neighborhood so most errands require a car.
This location is in the Busch neighborhood in Columbus. Nearby parks include Northgate Park, Edward S Thomas Nature Preserve and Devonshire Park.
Explore how far you can travel by car, bus, bike and foot from 6851 Sharon Court.
6851 Sharon Court has minimal transit which means it is possible to get on a bus.
6851 Sharon Court is in the Busch neighborhood. Busch is the 79th most walkable neighborhood in Columbus with a neighborhood Walk Score of 45.


Welcome to the 4th Grade CES!
I'm so excited to work with you this year! Please view this website regularly to see updates and news about what's going on in class. Homework will also be posted weekly under the homework tab. It's going to be a great year!


Blue Medora Care Systems Analytics for MEDITECH® is a monitoring and management solution designed for healthcare organizations that use the MEDITECH electronic health record (EHR) system. The solution extracts information from the MEDITECH system and integrates it with VMware vRealize™ Operations Manager™ to create a single view of system performance across the EHR and its supporting infrastructure.
What is Care System Analytics for MEDITECH?
Blue Medora Care Systems Analytics for MEDITECH leverages vRealize Operations Manager, an intelligent operations management solution from VMware, to improve visibility into the overall performance of the MEDITECH EHR system—from infrastructure to the point of care. It includes dashboards to visualize and analyze performance indicators from the EHR environment and related infrastructure (physical and virtual). This transparency increases collaboration across infrastructure, operations and applications teams.
How is Care Systems Analytics for MEDITECH used?
Overall view of the health of MEDITECH resources to detect anomalies from the normal behavior previously assessed by the analytics engine.
Drill down view for quickly browsing MEDITECH application-specific metrics alongside infrastructure metrics; for example: admissions, order entry, etc.
One-click trouble-shooting of problems that generate alerts or that result in calls.
Care Systems Analytics for MEDITECH provides value immediately when installed in a customer environment. For healthcare IT organizations interested in further customizing the solution, Blue Medora supports the creation of additional customized dashboards and multilevel alerts. Professional services can also help organizations improve data consolidation across the IT environment—physical and virtual—with storage devices, networking resources, and databases using generally available vRealize Operations Manager management packs. To see more Blue Medora management packs for VMware vRealize Operations visit the True Visibility Suite page.
How does Care Systems Analytics work with MEDITECH?
Blue Medora collaborated with Medical Information Technology, Inc. to obtain application level metrics from MEDITECH EHR. These, along with infrastructure metrics, are displayed in dashboards that will help in monitoring and pro-actively diagnose performance issues for MEDITECH customers.


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WALL-E, Morality, and Men Without Chests
How Not to Get Mad When Talking with Non-Believers
How to Debate Same-Sex Marriage After SCOTUS
What About Slavery in the Bible? (video)
C.S. Lewis on the Drive for Sexual Happiness
How Do We Defend Christian Values to Non-Christian...
The Events in Charleston Contradict the New Atheists
Do Miracles Count as Evidence for God's Existence?
Is God an Egomaniac for Desiring Worship?
Sean McDowell on Proof of a Messiah
How to Talk with Mormons (podcast)
Why the "Evil God" Objection Fails
Responding to Atheist Critiques of Christian Hypoc...
What Should We Think About Genetic Engineering?
Why Did the Culture Shift on Same-Sex Marriage? (v...
Criticism of the Bible Demonstrates the Bible's Power
The Rachel Dolezal Ordeal Shows Why Race, Like Bio...
Can God Use Natural Evil to Reduce Suffering?
Ministry Spotlight: The Poached Egg
What Counts as Natural Evil?
Why God Doesn't Reduce the Evil in the World?
Liberal Philosophy is Backfiring on Its Champions
Top Five Apologetics Blog Posts for May
Two Key Questions to Ask in the Same-Sex Marriage ...
Secularism's Undue Influence on Society
Secularism isn't a Neutral Position
God Allows Evil for the Good
Today's Snake Oil Includes a Scalpel: The Damaging...
Replying to Science-of-the-Gaps Arguments
Why Did the Culture Shift on Same-Sex Marriage? (video)
The Pew Research Center reports "in 2001, Americans opposed same-sex marriage by a 57% to 35% margin. Since then, support for same-sex marriage has steadily grown. Today, a majority of Americans (57%) support same-sex marriage, compared with 39% who oppose it."1
In this video, Lenny looks at the rise of the homosexual rights movement. He traces the coordinated effort to de-vilify homosexuality by masking it in popular media and how the Church didn't offer any good arguments against the push by activists. He also tells why it isn't too late to reclaim the high ground in the same-sex marriage debate. This video is the first in a three part series on building the case against same-sex marriage.
1.Pew Research. "Changing Attitudes on Gay Marriage." Pew Research Centers Religion Public Life Project. Pew Research Center, 07 June 2015. Web. 14 June 2015. http://www.pewforum.org/2015/06/08/graphics-slideshow-changing-attitudes-on-gay-marriage/.
Images courtesy Håkan Dahlström and licensed via the Creative Commons Attribution 2.0 Generic (CC BY 2.0) license.
Labels: America, apologetics, culture, homosexuality, marriage, Supreme Court


Before Stephanie can even step foot off Flight 127 Hawaii to Newark, she is knee deep in trouble. Her dream vacation turned into a nightmare, and she is flying back to New Jersey solo. Worse still, her seatmate never returned to the plane after the L.A. layover. Now he is dead, in a garbage can, waiting for curbside pickup. His killer could be anyone. And a ragtag collection of thugs and psychos, not to mention the FBI, are all looking for a photograph the dead man was supposed to be carrying. Only one other person has seen the missing photo, Stephanie Plum. Now she is the target, and she does not intend to end up in a garbage can. With the help of an FBI sketch artist Stephanie re-creates the person in the photo. Unfortunately the first sketch turns out to look like Tom Cruise, and the second sketch like Ashton Kutcher. Until Stephanie can improve her descriptive skills, she will need to watch her back.
While the lighter side of the Plum series is the main draw, it is nice to see that once in awhile it goes a bit darker. Stephanie has real bruises and knife nickmarks, and Morelli and Ranger had a knock-down drag-out fight, with Stephanie doing the dragging (it is only told as a past event, but still good even if you don't actually "see it").
Stephanie is up to her usual shenanigans with two hot men at her beck and call. She finally carries her gun regularly and it is loaded. . . As always, the supporting characters more than pay the price of admission. A solid contribution to the series and makes you want to keep reading.
there were too many sub-plots, and too many secondary characters to make this a fun story. It was choppy.
Love the whole series. Great Laughs. Occupies my time on BART between Daly City and Pleasant Hill.
When asked if she got married in Hawaii, Stephanie replied, 'Not exactly.' When asked to clarify, Stephanie said, 'It's complicated.' Her philosophy, inherited from her family, is that if you do not talk about a problem it might go away. This problem, as we learn, was a doozy.
'18' is a great story with many of the regular characters involved in the Plum series, and all of the staples – men breaking into Steph's apartment, viewing at Stivas, love triangle, goons like Slasher and Lancer, etc. Evanovich also added a little Razzle Dazzle to the story.
Another wonderful addition to the series!! Laughed Out Loud through the whole book!
At some point I'd really like Lula to be good for something rather than her typical worthless attitude and her need to constantly eat. A little character development would be nice.
You don't look for a lot of substance with this series; however, there's a lot of laughs!
Who reads this stuff!!! New York Times best selling author!!! Obviously, I did! Picked the book up from the one week read list to fill in inbetween books. I just can't believe that someone can make a living writing such stuff.
This was my first Evanovich read, and I was not impressed at all. I loved the main character and her mysterious men, however the writing was too simple and corny to say the least. I know that this is a part of a series so will try another.


The WS2812B is a bit addressable RGB LED. The WS2812B (don't confuse this with a WS2812 which has six pins) is a four pin device that is very simple to wire up to an Arduino. The LEDs can be daisy chained and are available as LED strips or discrete parts. Notice that no resistors are required because the WS2812B drives the physical LEDs with a pulse width modulated current source.
To program the LEDs a serial bit stream is sent to the input of the firsts WS2812B in the chain. The bit stream data contains three byte messages indicating the RGB intensity for each of the LEDs in the chain. For example to set the colours for a chain of three WS2812Bs we need to send 3*24 bits = 72 bits out from the Arduino. Each of the WS2812B devices replicates the input stream on its output pin so that at the end of the 72 bits each of the WS2812Bs will have a 24 bit RGB colour pattern. To update all of the LEDs the Arduino needs to send a synchronize pattern that signals the WS2812B to latch there current bit patterns; these are then updated on all of the LEDs simultaneously in effect displaying the colour messages that were shifted into the WS2812B chain.
The timing of the bit stream out of the Arduino is critical. If it is not correct the WS2812Bs will not recognize the colour messages with unpredictable results. To ensure that the timing is accurate the library uses assembly language instructions to accurately generate the required bit sequence. In order to ensure the clocking sequence is not altered the Arduino interrupts are also turned off temporarily. In the previous example 72bits were sent and each bit takes 1.25uS so the interrupts are off for 90uS which is quite short. Now imagine a LED strip with 100 RGB LEDs; the delay becomes 100LEDs*24bits/LED*1.25uS/bit= 3ms. which is a long time for interrupts to be off.
Installing the library is simply a matter of copying the WS2812B.zip folder into your Arduino project folder in the library directory. The next time you open the Arduino environment you will see the WS2812 library and examples in the Examples menu.
Each WS2812B draws 60mA when fully on so you can calculate the current draw as the #ofWS2812B*0.06A. Notice you can cut this current in half by only driving each colour from 0..127 which looks pretty much the same as full current.
The WS2812B can be driven from a 3.3V source but make sure that the data input is also driven at 3.3V.
Each WS2812B requires 24*1.25uS= 30uS to clock out the colour data. During this time the interrupts are off and this can effect your code if you run with interrupts. The Arduino millis() function uses interrupts.


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All images on this site are protected by copyright laws.
Copyright belongs to the individual photographers,
whose permission must be sought for use elsewhere.
Nelson Camera Club
What's New...
Digital Image Comp No. 3......
The last of our digital image competitions for this year was held on the 29th November, and our judge for the evening was one of our own members Mr. Gordon Bartley ARPS of Southport. It was Gordons task to choose the top 5 images from 2 sections, firstly the Nature section and then the General section. He did it on a round by round basis only eliminating what he thought was the weakest images in each round until he got down to his final choice of the top 5 in each section. Click here to view the winners.
Two members gain their CPAGB.....
On Saturday 26th November The Scottish Photographic Federation held The PAGB Awards for Photographic Merit at Stirling in Scotland were 2 of our members had sent their entries and also they both attended on the day.
Mr. Michael Whittaker & Mr. Tony Mellor both achieved good results with their entries and topped the 200 marks needed to gain the award, Michael got an overall score of 227 in the print section, and Tony got an overall score of 223 in the PDI section, so its congratulations to both of you, and you can now add the letters CPABG to your names. Well Done.
November Print Comp Results.....
The last of this years print competitions was held on Tuesday 1st November and as always we had an excellent response with quite a lot of images. Well its congratulations to Bill Smith once again who achieved top place with his superb portrait of "Alan" well done Bill. We must congratulate everyone who has entered prints over the year for the exceptional quality of prints that our members are producing, well done everyone keep up the good work. Click here to see the results.
Annual Themed Competition Results...
Our theme for this year was chosen by last years winner Mr. Ken Wilmore and his choice for this years theme was "Landmarks". We had 54 entries with landmarks from all over the world, and the competition was enjoyed by all. Lesley Whittaker came out the overall winner with her image of Brooklyn Bridge, also Lesley gets to choose next years theme.
Click here for the results.
ICPA Certificate of Merit.......
A Certificate of Merit was presented to Ken Wilmore at the club by the President, Jeff Needham.
This had been received from the ICPA in recognition of his award of 2nd place in the Colour Print section of the ICPA Annual Competition 2016 for his print "Female Blackbird Eating Berries"
Bill Smith gains PAGB Certificate
A certificate awarded by the PAGB in their Inter-Federation Print and Digital Image Competition and Exhibition 2016 was presented to Bill Smith for his Nature Digital Image "Fighting Starlings".
This image was used by the L&CPU as part of their entry and chosen by the PAGB for their Exhibition.
Congratulations Bill
SeptemberPrint Comp Results....
Print competition number 4 of 5 took place Tuesday 27th Sept. There were 31 prints in total, and they were judged by Adrian Hendley of Colne. Adrian kindly stepped in to judge at the last minute because the judge who we had booked could not make it.
Adrian once again did a first class of choosing the top 6 images which will go through to our Print of the Year competition to be held on 3rd January 2017.
Click here to see the winners.
Digital Image Comp No 2...
Results for the second of our Projected Image Competitions are now on the Competitions page under Results 2016.
We had 53 entries in total: 15 Nature, 38 General
Jane Lines was the judge and had much to contend with as we had a tremendous thunderstorm and the power went off in the building just as we were about to start.
The noise eventually stopped and we were able to carry on in peace, but Jane did make a start with the alarm still ringing, and as always did a splendid job of choosing the top 6 images from each category.
The two 1st places went to Tony Morris with Tour De France 2016 & Andy Pritchard with Red Kite Rolling into the Dive.
Click here to see the winners.
Nelson V Whitworth.....
Inter Club Battle
Tuesday 6th September Nelson CC had a return Battle with Whitworth PS held at Nelson.
Each club entered 15 digital images and 10 prints which were expertly judged by Harry Emmett of Accrington.
His comments and constructive critique made for a most enjoyable evening.
Digital Images were first and Nelson gained a maximum score of 20 for two images - "Tiger" by Jean Greenwood and "Wasp on Ivy" by Andy Pritchard.
Total scores in this section - Nelson 256 Whitworth 226
Next came the prints which was a much closer contest with Whitworth having the only maximum score of 20 for "Dipper" by K Duffy.
Nelson however just had the edge. Total scores - Nelson 169 Whitworth 164
Nelson therefore were the overall winners - Nelson 425 Whitworth 390
A good night enjoyed by all
August Print Comp, Results.....
Results are now on the competitions page under Results 2016.
Its congratulations to Michael Whittaker again who took the top spot with a portrait of "Susan" well done.
Our judge for the evening was Barry Noon of Altham who did a remarkable job of choosing the top 6 places out of a total entry of 37 prints. Click here to see the winners.
ICPA, Annual Competition 2016 Results....
We now have the results from the ICPA (Inter Club Photographic Alliance) Annual Competition 2016 in which 15 clubs made an entry.
In the Colour Print Competition -
Nelson CC came 2nd with 76 marks.
Ken Wilmore received a maximum score of 20 for "Female Blackbird Eating Berries" which was given a second place in the competition.
The winning club was Chorley with 78 marks.
In the Digital Projected Image Competition -
Nelson CC came 4th with 70 Marks.
The winning club was Leyland with 76 marks
In the Monochrome Print Competition -
Nelson came 11th with 67 marks.
The winning club was Chorley with 76 marks
The individual scores can be found on the ICPA website inter-clubphotographicalliance.weebly.com
On the homepage click Learn More under Results - then click on PDI Results/Colour Print Results/ Monochrome Print results
A very creditable performance by the club
Judges & Judging.....
A new article has now been put on the Tutorials Page about judges & judging, its quite long but has some interesting points. Click here to go to Tutorials.
Syllabus.....
The syllabus for the second half of the year has now been published, go over to our Club Diary page to see whos on and when or click here to go straight there.
May's Print Competition Results......
The second print competition of 2016 was held on Tuesday 24th May, we had 32 entries, our judge for the evening was Mark Williams from Chorley. Mark held back 9 images from the folio which he then had to choose 6 to go through to our image of the year competition which will be held on 3rd January 2017.
Congratulations to Michael Whittaker on getting 1st place and we look forward to seeing more of his work in the coming months.
To see the images click here.
May's PDI Competition Results......
Results of our first Digital Image Competition have now been published on our Results 2016 page.
We had a good start to the season with 58 entries, 31 in the General category and 27 in the Nature category.
Mike Davies of Rochdale was the judge for the evening with his comments and remarks being well received.
Click here to go to the Results 2016 page to see the images.
L&CPU IndividualsComp, results.....
The results from the L&CPU Individuals Competition May 2016 have just been published. Four of our members entered.
In the Digital Worker of the Year: Entries from 125 workers. (12 images per worker)
Walker came 23rd with 133 marks
Bill Smith came 36th with 131 marks
Andy Pritchard and Tony Mellor came joint 51st with 128 marks
In the Print Worker of the Year: Entries from 49 workers (12 prints per worker)
Tony Mellor came 37th with 122 marks
In the Photographer of the Year: Entries from 41 workers,(12 prints and 12 Digital Images)
7 prints have been retained for the Folios.
Well done to you all.
Click here to see Individual scores.
April Print Competition......
The first of five print competitions for 2016 got under way on Tuesday 26th April. We received 42 entries and the judge for the evening was Mr. Mike Lawrence from Oldham who remarked about the high standard of our members work, and that judging this competition was not going to be an easy task. In the end it was Howard Harrisons print of a Nuthatch that came out the overall winner. Congratulations to Howard and all those who entered the competition, well done.
Inter Club Battle......
Monday 18th April, Nelson CC did battle with Whitworth PS.
Each club had 25 entries, 15 digital and 10 prints, an external judge was booked (Mr. Mike Lawrence of Oldham C) both teams turned up for an 8 o'clock start, this was held at Whitworth venue, which has a bar I might add, so with beer in hand let battle commence.
Digital images was first up and although Nelson had the best image with a score of 20 points, (Congratulations to Walker with Liverpool Remembers) Whitworth came out the winner with 253 points against Nelson with 250.
Next came the prints and again Nelson had the best print scoring 20 points, (Congratulations to Roger Johnstone with Lone Tree at Winskill) but after judging was over the totals had to be counted a few times, before Nelson CC came out the overall winners. Nelson scored 173 points with their prints and Whitworth scored 164.
Final scores Nelson CC 423, Whitworth PS 417.
A good night was had by both clubs, and we look forward to the return battle later on in the year.
Free Free Free.....Nik Filters Announcement...
Today we're making the Nik Collection available to everyone, for free.
Photo enthusiasts all over the world use the Nik Collection to get the best out of their images every day. As we continue to focus our long-term investments in building incredible photo editing tools for mobile, including Google Photos and Snapseed, we've decided to make the Nik Collection desktop suite available for free, so that now anyone can use it.
Follow this link to get your free download...........
www.google.com/nikcollection/
ICPA Annual Digital Projected Image Knockout
The ICPA Annual Digital Projected Image Knockout was held last night, Saturday 12th March 2016 at the Canberra Club, Salmesbury Aerodrome, hosted by Blackburn Camera Club
15 clubs entered (10 images per club) and Nelson Camera Club gained a very creditable 3rd place with 42 points only 8 points behind the winners which was Chorley Photographic Society.
Congratulations to Chorley on winning, and congratulations to Nelson on a very respectable 3rd place.
Scores Chorley PS 1st = 50
Leyland PS 2nd = 46
Nelson CC 3rd = 42
Ribblesdale CC 3rd = 42
Bury PS 5th = 41
Preston PS 5th = 41
Blackburn CC 7th = 37
Padiham PS 8th = 36
Rochdale PS 8th = 36
Colne CC 10th = 33
Darwen CC 10th = 33
Burnley 12th = 32
Rochdale CC 12th = 32
Bacup CC 14th = 31
Accrington 15th = 28
L&CPU Annual Club Digital Comp Results....
Nelson CC did really well in the L&CPU Annual Digital Club Competition on Saturday 27th February 2016.
Here are the results we achieved.......
Colour Digital.....20th place out of 42 entries
Mono Digital.....13th place out of 42 entries
Nature Digital.....10th place out of 42 entries.
Final Club Ranking...Joint 14th with a total score of 267.
Congratulations to everyone who entered.
Tutorial Added......
A new tutorial has been added to the tutorials page, recommended by Geoff Proctor, all about how to use refine Edge. Click here to go there.
Revised Monthly Competition Rules.....
Before entering this years competitions please read the new rules which have been revised from February 2016.
Go over to the competitions page or click here to read them.
Saturday 27th February 2016
Our Annual Dinner and Awards Presentation was held tonight at the ACE Centre in Nelson. Thirty two members attended, making 4 tables of 8. We all had a really good night and once again the catering staff at the ACE Centre put on a really good meal. Thanks to all who attended the Annual Dinner for making it such a good evening, and a really big thank you to all the staff at the ACE Centre for such a good meal and the excellent service they provided for us.
Click here to see all the Annual Competition results.
Congratulations to all the winners - especially to Bill Smith, who produced some amazing photographs to win 5 trophys out of six - a remarkable achievement. The other trophy went to Walker for her entry "Healy Dell". Congratulations to ALL competitors for producing such a high standard in this year's Annual Competitions.
5 Minute AV Comp....
Our first competition of the year was held on Tuesday 2nd February, it was our Audio Visual Competition for members only. This competition had 15 entries, all of them very entertaining. The competition was judged by our members, and the winning entry was that of Tony Mellor, entitled Pond Life. Well done to all who entered and made it such a good night.
New Gallery.....
Howard Harrison has now published his Gallery of Images, click here to see them.
Change of Speaker.......
We have a change in speaker for the 9th February 2016.
Our speaker is now Chris Freeman of Halifax and his talk is titled " Jungle Look " The birds, the bees and the Kapok trees.
Apologies for any inconvenience.
John Moore
It's with great sadness that we have to announce the death of John Moore on Thursday 21st January 2016. John had been a valued member of Nelson Camera Club for many years.
Always a true gentleman, and never a complaint as he struggled with increasing difficulties in mobility.
He will be greatly missed.
Annual general Meeting...
Our AGM was held on Tuesday 19th January and the new officials have now been published on the Who's Who at the club page click here to go there and get to know who's who.
There was only 1 change to club competition rules, and that was to Digital Image Competitions, previously we could enter 4 images into these competitions, this has now been reduced to 3 from now on. The committee thought that we were getting to many entries, and a reduction to 3 images per person would give the judges more time to appraise each image.
ICPA Website.....
The Inter Club Photographic Alliance now have their own website, to see what's going on in the Alliance click on this link ICPA or click on their logo on our home page.
Print & Projected Image of the Year 2015........
Bill Smith does it again, and a double this time.
Bill carries on with his winning streak right up to the end of 2015, not only did he get awarded Print of the Year, he was also awarded Projected Image of the Year. ( See Images )
The judge for the evening was Adrian Lines, the image shows Bill receiving his trophy's from Adrian who once again did a superb job judging our Image of the Year Competition.
Congratulation once again to Mr Bill Smith.
Syllabus
The syllabus for the first part of the year has now been published, click here to go there.
Updated Gallery......
Bill Smith has updated his Gallery of Images
click here to see them.
Honorary Members.....
Nelson Camera Club are delighted to announce that we now have three new honorary members, Mr Edward Charlesworth, Mr Edmund Hirst and Mrs Iris Hirst. Our three new honorary members between them have served Nelson Camera Club over the years in many different ways from being the president, secretary, committee, and a host of other duties right down to making and serving cups of tea & coffee.
Their certificates of honorary membership was awarded on the 15th December 2015.
Congratulations to each of you, and a big thank you from all the members at our club.
Our three new Honorary Members.
Mr Edward Charlesworth,
Mr & Mrs Edmund Hirst.
Mr. John Moore
Tony Mellor receiving his trophy for his winning entry "Pond Life" from Jeff Needham, president of Nelson Camera Club
Images from the Annual Dinner
A selection from the
 L&CPU Digital Club Competition
Our ICPA Entry 2016
May's Print Competition
A small selection from our entry.
"Tiger" by Jean Greenwood, "Wasp on Ivy" by Andy Pritchard,
and " Dipper " by Kevin Duffy.
Tour De France 2016 &
Red Kite Rolling into the Dive
Wild Little Owl by Howard Harrison
"Fighting Starlings"
Nuthatch in the Rain
Michael's Entry
Tony's Entry


Our client brought a claim on behalf of his Mother who fell out of her hospital bed and sustained a fracture to her hip and severe facial bruising. She sadly passed away just 4 months later.
Our client has said that he would be certain to recommend us to others because he found us informative, helpful and easy to communicate with.


Interviews, articles, and reviews from various news sources.
Official press release biography for Flyleaf, including past and present.
Various historical Flyleaf accounts courtesy of Jared's grandfather.
See how Flyleaf has been doing on the charts.
Commonly asked questions about Flyleaf.
Passages from the Memento Mori booklet.
Lyrics to every Flyleaf song. Ever. No really.
Jared & Sameer's guitar rig setups. These are old, but still cool.
A nearly complete archive of every tour date Flyleaf has played.
Information about Flyleaf's video releases.


text:
HomePower Systems
Inductance of 3-Phase Line with Unsymmetrical Spacing and Transposed
Inductance is one of the transmission line parameters. As the transmission lines carry alternating currents which produce alternating magnetic fluxes, the number of flux linkages with the conductor changes and hence causes inductance to be present in the line which is the ratio of total magnetic flux linkages to the current flowing through it. This inductance limits the power transfer capability of the line.
Hence, it is essential to calculate the inductance of the transmission line for analysis. let us see the expression for the inductance of the 3-phase transmission line when the conductors are unequally spaced.
Inductance of Unsymmeterically Spaced 3-Phase Transmission Line :
Consider a 3-phase overhead transmission line with phase conductors a,b, and c of radius r each spaced unsymmetrically such that the distance between the three conductors is D1, D2, and D3 as shown in the figure below. Let Ia, Ib, and Ic be the currents flowing in the conductors a, b, and c respectively.
Assume that the whole system is balanced which leads to the flow of equal currents in the conductors i.e., Ia = Ib = Ic = I(say). The currents Ia, Ib, and Ic are displaced at 120° apart from each other. If Ia is taken as the reference phasor then the currents are given by,
We know that the flux linkage of any conductor, in a group of conductors, is due to its own current and currents in the other conductors. Therefore, flux linkage of the conductor 'a' is due to its own current and currents in the conductors 'b' and 'c', and it is given by,
Similarly, flux linkages of conductors 'b' and 'c' is given by,
Where, r' = Geometric mean radius (GMR) of conductor = 0.07788 × r. Substituting the values of Ia, Ib, and Ic in the above equation we get,
We know that the inductance La is given by,
Similarly, the inductance due to the conductors 'b' and 'c' can be calculated and they are given by,
When conductors are unsymmetrically spaced in a 3-phase line, the flux linkage and inductance per phase are not identical, and knowing the inductance of each phase becomes complicated and it results in an unbalanced circuit.
The equilibrium in the circuit can be retained by shifting the places of the conductor at every period of time such that the conductors take the initial place of every conductor at the same distances. Such an arrangement of the conductor's position obtained by shifting their places is called transposition. By transposition, we can obtain almost the same inductance between the conductors. Let us see the expression for inductance when the 3-phase line is transposed.
Inductance of Unsymmeterically Spaced 3-Phase Transmission Line When Transposed :
The simple configuration of a 3-phase conductor is shown in the figure. As the conductors are transposed, so their position in the transposition cycle would be as shown in the figure below.
When the conductors are connected in parallel, it results in low inductance keeping the distance between phases as small as possible. For deriving the inductance per phase of 3-phase conductors placed unsymmetrically, we need to determine the flux linkage of each conductor for every position it occupies in a transposition cycle. After that, we can determine the average flux linkages. So, the flux linkage of phase 'a' in position 1 is given as,
When 'a' is in position 2, 'b' in position 3 and 'c' in position 1,
When 'a' is in position 3, 'b' in position 1, and 'c' in position 2,
The average value of flux linkage of a single-phase 'a' is,
We know that,
Therefore, the average inductance per phase is,
Deq = Geometric mean of three distances of unsymmetrical line
Ds = GMR (geometric mean radius) of the conductor.
The above expression is the inductance per phase of a 3-phase transmission line with unsymmetrical spacing but lines are transposed. Nowadays the transposition of conductors is made at switching stations to balance inductance.