Sigma Box
Christian Erdmann
Sigma's original name may have been san, but due to the complicated early history of the Greek epichoric alphabets, san came to be identified as a separate letter in the Greek alphabet, represented as Ϻ.[2]Herodotus reports that "san" was the name given by the Dorians to the same letter called "sigma" by the Ionians.[i][3]
In Greek inscriptions from the late first century BC onwards, Ͻ was an abbreviation indicating that a man's father's name is the same as his own name, thus Dionysodoros son of Dionysodoros would be written Διονυσόδωρος Ͻ (Dionysodoros Dionysodorou).[7][8]
Sigma was adopted in the Old Italic alphabets beginning in the 8th century BC.At that time a simplified three-stroke version, omitting the lowermost stroke, was already found in Western Greek alphabets,and was incorporated into classical Etruscan and Oscan, as well as in the earliest Latin epigraphy (early Latin S), such as the Duenos inscription.The alternation between three and four (and occasionally more than four) strokes was also adopted into the early runic alphabet (early form of the s-rune).Both the Anglo-Saxon runes and the Younger Futhark consistently use the simplified three-stroke version.
The most basic use case: you have a graph dataset, with colors, sizes and positions for each node. For instance, you exported a GEXF graph file from Gephi. You want to visualize it using on a web page.
Sigma.js renders graphs using WebGL. It allows drawing larger graphs faster than with Canvas or SVG based solutions. It also makes custom rendering way harder to develop. If you have small graphs (like a few hundreds of nodes and edges) and/or if you need very customized rendering, then d3.js is indeed a best fit for you.
Yes it is possible, but harder, because we do not have a wrapper yet. So you will have to bind sigma.js lifecycle to your app manually. It is not necessarily too difficult though, please take a look on this repository which offers a quick example.
In the LHC, millions of particle collisions per second are tracked by the detectors and filtered through trigger systems to identify decays of rare particles. Scientists then analyse the filtered data to look for anomalies, which can indicate new physics.
The normal distribution has some interesting properties. It is symmetrical, its peak is called the mean and the data spread is measured using standard deviation. For data that follows a normal distribution, the probability of a data point being within one standard deviation of the mean value is 68%, within two is 95%, within three is even higher.
Standard deviation is represented by the Greek letter σ, or sigma. Measured by numbers of standard deviations from the mean, statistical significance is how far away a certain data point lies from its expected value.
When scientists record data from the LHC, it is natural that there are small bumps and statistical fluctuations, but these are generally close to the expected value. There is an indication of a new result when there is a larger anomaly. At which point can this anomaly be classified as a new phenomenon? Scientists use statistics to find this out.
A result that has a statistical significance of five sigma means the almost certain likelihood that a bump in the data is caused by a new phenomenon, rather than a statistical fluctuation. Scientists calculate this by measuring the signal against the expected fluctuations in the background noise across the whole range. For some results, whose anomalies could lie in either direction above or below the expected value, a significance of five sigma is the 0.00006% chance the data is fluctuation. For other results, like the Higgs boson discovery, a five-sigma significance is the 0.00003% likelihood of a statistical fluctuation, as scientists look for data that exceeds the five-sigma value on one half of the normal distribution graph.
In most areas of science that use statistical analysis, the five-sigma threshold seems overkill. In a population study, such as polls for how people will vote, usually a result with three sigma statistical significance would suffice. However, when discussing the very fabric of the Universe, scientists aim to be as precise as possible. The results of the fundamental nature of matter are high impact and have significant repercussions if they are wrong.
In the past, physicists have noticed results that could indicate new discoveries, with the data having only three to four sigma statistical significance. These have often been disproven as more data is collected.
If there is a systematic error, such as a miscalculation, the high initial significance of five sigma may mean that the results are not completely void. However, this means that the result is not definite and cannot be used to make a claim for a new discovery.
Whether five sigma is enough statistical significance can be determined by comparing the probability of the new hypothesis with the chance it is a statistical fluctuation, taking the theory into account.
In this paper, Lyons also deems five sigma statistical significance to be enough for the Higgs boson discovery. This is because the theory for the Higgs boson had been predicted, mathematically tested, and generally accepted by the particle physics community well-before the LHC could generate conditions to be able to observe it. But once this was achieved, it still required a high statistical significance to determine if the signal detected was indeed a discovery.
A statistical significance of five sigma is rigorous, but it is really a minimum. A higher value for statistical significance cements data as being more reliable. However, achieving results with statistical significance of six, seven, or even eight sigma requires a lot more data, a lot more time, and a lot more energy. In other words, a probability of at most 0.00006% that a new phenomenon is not a statistical fluke is good enough.
The journal was founded on a volunteer basis in 2005 at the Institute of Mathematics of the NAS of Ukraine by the following people: Vyacheslav Boyko, Anatoly Nikitin, Roman Popovych, Iryna Yehorchenko and Alexander Zhalij.
Please submit the paper to arXiv.org and send the arXiv numberto edi...@sigma-journal.comor (in exceptional cases only) you can send the zipped paper in TeX/LaTeX format directly toed...@sigma-journal.com (please include the PDF or PostScript file aswell) with an explanation why you prefer not to put the paper to arXiv.
Your article can be prepared for submission in any TeX-style of your choice. However, we would like to point out that after the paper is accepted for publication you should prepare the paper using the SIGMA style (the LaTeX style file for can be downloaded from here).
Please indicate in your submission if your paper is intended fora specific special issue of SIGMA.If the receipt of your paper is not acknowledged within two working days, please resend it to our alternative e-mail address sigmaj...@gmail.com
Manuscripts submitted as regular articles are expected to be
- new and original;
- well organized and clearly written;
- of interest to the scientific community;
- not published previously and not under consideration for publicationin any other journal or book.
Review articles are welcome too.Review articles are critical evaluations of material that has alreadybeen published. By organizing, integrating and evaluating previouslypublished material, the author of a review article considers theprogress of current research toward clarifying a problem. In a sense,a review article is a tutorial in that the author
- defines and clarifies the problem;
- summarizes previous investigations in order to inform the reader ofthe state of current research;
- identifies relations, contradictions, gaps, and inconsistencies in theliterature;
- and suggests a next step or steps in solving the problem.
All the papers submitted to SIGMA are sent for refereeing to at least two experts in the specific areas for evaluation according to the above criteria. These referees can either review the papers themselves or recommend alternative referee(s).
We strive to ensure an adequate refereeing and selection process. At the moment around 60 percent of the submitted papers are rejected. Mostof the accepted papers have been amended according to thereferees' recommendations.
We would like to stress that all papers in the specialissues should be original: they should not besimply reviews of authors' own work that is alreadypublished elsewhere. Acceptance of the paper is subject to the results of the peer reviewprocess according to regular refereeing rules of SIGMA (see the itemsabove).
Free for authors
Despite being open access, we do not charge our authors for publication (i.e., SIGMA uses the so-called diamond open access model). Many authors submitting good papers cannot afford to pay page charges for various reasons and we do not want to put them at a disadvantage compared to those who can pay. On the other hand, when a journal charges their authors forpublication, the requirements of thorough review may contradict financial interests of the journal. This often results in the publication of low-quality papers without adequate peer review and discredits the very idea of open access.
What are the sources for SIGMA existence?
SIGMA receives major funding from the Foundation Compositio Mathematica and the University Library of the Radboud University Nijmegen.Also, one-time donations have been received from Sociedad Mexicana de Fsica, University Libraries of the Delft University of Technology, Uppsala University and University of Amsterdam. It is a great pleasure for SIGMA to acknowledge these. We greatly appreciate also the assistance of EMIS who kindly provides mirrors for SIGMA.
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The above support covers only a part of SIGMA costs. We need money for the support of volunteers doing technical work for SIGMA, including but not limited to the copyediting. So, if your organization would like to support us financially, please contact us.