Summary

HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

Expand All
Entries
Biography
René Sotelo
René Sotelo (6 November 1962) is a Venezuelan robotic surgeon, urologist-oncologist and university professor.[1][2] Sotelo received his medical degree from Central University of Venezuela[3] and his residency in General Surgery and Urology was at Domingo Luciani Hospital, Venezuela. He completed fellowship in Urologic Oncology at the Hospital Padre Machado in Caracas, Venezuela; training in
  • 16.6K
  • 18 Nov 2022
Topic Review
Alvin Plantinga's Free Will Defense
Alvin Plantinga's free will defense is a logical argument developed by American analytic philosopher Alvin Plantinga, the John A. O'Brien Professor of Philosophy Emeritus at the University of Notre Dame, and published in its final version in his 1977 book God, Freedom, and Evil. Plantinga's argument is a defense against the logical problem of evil as formulated by philosopher J. L. Mackie beginning in 1955. Mackie's formulation of the logical problem of evil argued that three attributes of God, omniscience, omnipotence, and omnibenevolence, in orthodox Christian theism are logically incompatible with the existence of evil. In 1982, Mackie conceded that Plantinga's defense successfully refuted his argument in The Miracle of Theism, though he did not claim that the problem of evil had been put to rest.
  • 12.4K
  • 18 Nov 2022
Topic Review
Effective Atomic Number
Effective atomic number has two different meanings: one that is the effective nuclear charge of an atom, and one that calculates the average atomic number for a compound or mixture of materials. Both are abbreviated Zeff.
  • 4.2K
  • 22 Nov 2022
Topic Review
Matthews Correlation Coefficient
The Matthews correlation coefficient (MCC) or phi coefficient is used in machine learning as a measure of the quality of binary (two-class) classifications, introduced by biochemist Brian W. Matthews in 1975. The MCC is defined identically to Pearson's phi coefficient, introduced by Karl Pearson, also known as the Yule phi coefficient from its introduction by Udny Yule in 1912. Despite these antecedents which predate Matthews's use by several decades, the term MCC is widely used in the field of bioinformatics and machine learning. The coefficient takes into account true and false positives and negatives and is generally regarded as a balanced measure which can be used even if the classes are of very different sizes. The MCC is in essence a correlation coefficient between the observed and predicted binary classifications; it returns a value between −1 and +1. A coefficient of +1 represents a perfect prediction, 0 no better than random prediction and −1 indicates total disagreement between prediction and observation. However, if MCC equals neither −1, 0, or +1, it is not a reliable indicator of how similar a predictor is to random guessing because MCC is dependent on the dataset. MCC is closely related to the chi-square statistic for a 2×2 contingency table where n is the total number of observations. While there is no perfect way of describing the confusion matrix of true and false positives and negatives by a single number, the Matthews correlation coefficient is generally regarded as being one of the best such measures. Other measures, such as the proportion of correct predictions (also termed accuracy), are not useful when the two classes are of very different sizes. For example, assigning every object to the larger set achieves a high proportion of correct predictions, but is not generally a useful classification. The MCC can be calculated directly from the confusion matrix using the formula: In this equation, TP is the number of true positives, TN the number of true negatives, FP the number of false positives and FN the number of false negatives. If any of the four sums in the denominator is zero, the denominator can be arbitrarily set to one; this results in a Matthews correlation coefficient of zero, which can be shown to be the correct limiting value. The MCC can be calculated with the formula: using the positive predictive value, the true positive rate, the true negative rate, the negative predictive value, the false discovery rate, the false negative rate, the false positive rate, and the false omission rate. The original formula as given by Matthews was: This is equal to the formula given above. As a correlation coefficient, the Matthews correlation coefficient is the geometric mean of the regression coefficients of the problem and its dual. The component regression coefficients of the Matthews correlation coefficient are Markedness (Δp) and Youden's J statistic (Informedness or Δp'). Markedness and Informedness correspond to different directions of information flow and generalize Youden's J statistic, the [math]\displaystyle{ \delta }[/math]p statistics and (as their geometric mean) the Matthews Correlation Coefficient to more than two classes. Some scientists claim the Matthews correlation coefficient to be the most informative single score to establish the quality of a binary classifier prediction in a confusion matrix context.
  • 8.1K
  • 18 Nov 2022
Biography
Andrew Jenike
Dr. Andrew "Andy" W. Jenike (16 April 1914 - 8 August 2003) was an American engineer who developed and expanded the science of bulk material handling. He founded and served as company president for engineering consulting firm Jenike & Johanson, Inc. and published Utah Engineering Experiment Station Bulletins 123 and 108, which introduce the idea of mass flow. Andrew Jenike was born in Poland
  • 805
  • 18 Nov 2022
Topic Review
BSAVE (Bitmap Format)
A BSAVE Image (aka "BSAVED Image") as it is referenced in a graphics program is an image file format created usually by saving raw video memory to disk (sometimes but not always in a BASIC program using the BSAVE command). The BASIC BSAVE command is a general command meant for dumping ranges of memory addresses to disk. Data could be recalled using the counterpart BLOAD command. Some platforms provided a BRUN command that would immediately attempt to execute the loaded RAM image as a program. BSAVE was in general use as a file format when the IBM PC was introduced. It was also in general use on the Apple II in the same time period. Although the commands were available on the Commodore PET line, they were removed from the later (and more popular) Commodore 64 and VIC-20 computers. In 1985 the Commodore 128 was released with Commodore BASIC version 7.0 which restored the BSAVE and BLOAD commands.
  • 1.8K
  • 22 Nov 2022
Topic Review
MDFAT
DriveSpace (initially known as DoubleSpace) is a disk compression utility supplied with MS-DOS starting from version 6.0 in 1993 and ending in 2000 with the release of Windows Me. The purpose of DriveSpace is to increase the amount of data the user could store on disks by transparently compressing and decompressing data on-the-fly. It is primarily intended for use with hard drives, but use for floppy disks is also supported. This feature was removed in Windows XP and later.
  • 524
  • 18 Nov 2022
Topic Review
Akai AX60
The AX60 is a polyphonic analogue keyboard synthesizer manufactured by Akai Professional in the mid-1980s. It was Akai's answer to the popular Roland Juno series synthesizers. The AX60 uses voltage-controlled analogue oscillators and filter circuitry based on the Curtis Electronics CEM 3394 integrated circuit.
  • 637
  • 18 Nov 2022
Topic Review
Scientist.com
Scientist.com (formerly known as Assay Depot) is a network of public and private e-commerce marketplaces that connect buyers and sellers of scientific research services. The company was founded in 2007 by Kevin Lustig, Chris Petersen and Andrew Martin and launched its first public research marketplace in September 2008.
  • 1.9K
  • 18 Nov 2022
Topic Review
Lithium Technologies
Lithium Technologies is a San Francisco-based provider of software that allows businesses to connect with their customers on social media and digital channels. Lithium was founded in 2001 as a spin-out from GX Media, which created technologies for professional rankings and tournaments and now hosts a number of popular gaming sites. The company's founders include Dennis Fong, Lyle Fong, Michel Thouati, Kirk Yokomizo, John Joh, Nader Alizadeh, Michael Yang, and Matt Ayres. The Lithium platform comprises a set of products for digital marketing and social customer support, including Lithium Communities, which act as the hub for a brand's digital conversations; Lithium Response, a social customer care tool; and Lithium Reach a social media management tool. Klout data powers the Lithium platform with its proprietary algorithms and volume of data with over 750M scored profiles." Lithium's SaaS platform combines online customer community applications such as forums, blogs, innovation management, product reviews, and tribal knowledge bases with the broader social web and traditional CRM business processes, resulting in a wide range of online customer interaction methods. Stemming from its gaming roots, the platform incorporates elaborate rating systems for contributors, with ranks, badges, and "kudos counts". Lithium hosts an annual user conference, LiNC (Lithium Networking Conference) designed to give digital strategists a deeper understanding of trends in social customer engagement. Since its inception in 2008, the event has grown 1,100% to 900+ attendees in 2016. In 2017, the company held a series of localized LiNC events in cities like London, San Francisco, and Sydney.
  • 2.0K
  • 18 Nov 2022
  • Page
  • of
  • 863

Other Entry Collections

>>