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Topic Review
Training, Validation, and Test Sets
In machine learning, a common task is the study and construction of algorithms that can learn from and make predictions on data. Such algorithms function by making data-driven predictions or decisions, through building a mathematical model from input data. These input data used to build the model are usually divided in multiple data sets. In particular, three data sets are commonly used in different stages of the creation of the model: training, validation and test sets. The model is initially fit on a training data set, which is a set of examples used to fit the parameters (e.g. weights of connections between neurons in artificial neural networks) of the model. The model (e.g. a naive Bayes classifier) is trained on the training data set using a supervised learning method, for example using optimization methods such as gradient descent or stochastic gradient descent. In practice, the training data set often consists of pairs of an input vector (or scalar) and the corresponding output vector (or scalar), where the answer key is commonly denoted as the target (or label). The current model is run with the training data set and produces a result, which is then compared with the target, for each input vector in the training data set. Based on the result of the comparison and the specific learning algorithm being used, the parameters of the model are adjusted. The model fitting can include both variable selection and parameter estimation. Successively, the fitted model is used to predict the responses for the observations in a second data set called the validation data set. The validation data set provides an unbiased evaluation of a model fit on the training data set while tuning the model's hyperparameters (e.g. the number of hidden units—layers and layer widths—in a neural network). Validation datasets can be used for regularization by early stopping (stopping training when the error on the validation data set increases, as this is a sign of over-fitting to the training data set). This simple procedure is complicated in practice by the fact that the validation dataset's error may fluctuate during training, producing multiple local minima. This complication has led to the creation of many ad-hoc rules for deciding when over-fitting has truly begun. Finally, the test data set is a data set used to provide an unbiased evaluation of a final model fit on the training data set. If the data in the test data set has never been used in training (for example in cross-validation), the test data set is also called a holdout data set. The term "validation set" is sometimes used instead of "test set" in some literature (e.g., if the original data set was partitioned into only two subsets, the test set might be referred to as the validation set). Deciding the sizes and strategies for data set division in training, test and validation sets is very dependent on the problem and data available.
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  • 17 Oct 2022
Topic Review
Ohlone Tiger Beetle
The Ohlone tiger beetle, Cicindela ohlone, is endemic to California. It was discovered in 1987 and named and described in 1993. C. ohlone is most closely related to Cicindela purpurea. C. ohlone ranges in length from 9½ mm to 12½ mm with the females at the higher end of the range. The body is a bright, sericate green with bronze tints on the dorsum and the elytra. C. ohlone differs from other purpurea in that it has a larger body size, different genital morphology and different seasonal activity cycle.
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  • 17 Oct 2022
Topic Review
Voltaire
François-Marie Arouet (French: [fʁɑ̃swa maʁi aʁwɛ]; 21 November 1694 – 30 May 1778), known by his nom de plume Voltaire (/vɒlˈtɛər, voʊl-/; also US: /vɔːl-/, French: [vɔltɛːʁ]), was a French Enlightenment writer, historian, and philosopher famous for his wit, his criticism of Christianity—especially the Roman Catholic Church—as well as his advocacy of freedom of speech, freedom of religion, and separation of church and state. Voltaire was a versatile and prolific writer, producing works in almost every literary form, including plays, poems, novels, essays, histories, and scientific expositions. He wrote more than 20,000 letters and 2,000 books and pamphlets. He was an outspoken advocate of civil liberties, and was at constant risk from the strict censorship laws of the Catholic French monarchy. His polemics witheringly satirized intolerance, religious dogma, and the French institutions of his day.
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  • 17 Oct 2022
Topic Review
Department of Geodesy GUT
Department of Geodesy Gdansk University of Technology – continues the tradition of the Department of Surveying and Cartography, established at Gdansk University of Technology in 1945 (formal appointment of the new Department: October 1, 1945, and the formal appointment of the head of the Department: September 1, 1946). In the annals of the Gdansk University of Technology the Department of Geodesy appears for the first time at the Technical University (Preussische Königliche Technische Hochschule) and the Faculty of Civil Engineering (1904). The first head of the Department of Geodesy was Prof. Hermann Otto Paul Eggert (b. 4 February 1874 in Tilsit, d. January 20, 1944 in Gdansk). In 1921–1937 the next head of the Institute of Geodesy was Prof. Dr. Wilhelm Lührs. In 1938–1945 the Institute of Geodesy and Geometry was led by Prof. Paul Albert Ulrich Graf (February 6, 1908, in Wolgast – September 11, 1954, in Düsseldorf). The Department of Geodesy at the Gdansk University of Technology is the oldest in the present Polish unit dealing with science and education in the field of geodesy and cartography (currently in the field of civil engineering and transport). After 1945, the Department of Geodesy was led by: Department of Geodesy - previous names:
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  • 17 Oct 2022
Topic Review
Community Counseling
Guidance and counseling is a process of helping an individual become fully aware of his/ herself and the ways in which he is responding to the influence of his/her environment. Counseling is a generic term for any of professional counseling that treats dysfunction occurring within a group of related people. This term describes a preventive system of counseling that works to combat psychological impairment through the improvement and development of community support. A community is defined as a group of interacting individuals who share a commonality. This commonality can be anything from location of residence to career interest, but a community counselor will use this common characteristic to council groups of people.
  • 7.0K
  • 17 Oct 2022
Topic Review
Economy Car
An economy car is an automobile that is designed for low-cost purchase and operation. Typical economy cars are small (compact or subcompact), lightweight, and inexpensive to buy. Economy car designers are forced by stringent design constraints to be inventive. Many innovations in automobile design were originally developed for economy cars, such as the Ford Model T and the Austin Mini. The alternative approach, other than innovating to build a low-cost car, is to build a stripped-down, no-frills version of a conventional car. Gordon Murray, the Formula 1 and McLaren F1 designer, said when designing his new Murray T.25 city car: "I would say that building a car to sell for six thousand pounds and designing that for a high-volume production, where you have all the quality issues under control, is a hundred times more difficult than designing a McLaren F1, or even a racing car. It is certainly the biggest challenge I've ever had from a design point of view."
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  • 17 Oct 2022
Topic Review
Climate Apocalypse
A climate apocalypse (also called a climate dystopia and a climate-induced collapse, among other names) is a hypothetical scenario involving the global collapse of human civilization and potential human extinction as either a direct or indirect result of anthropogenic climate change and ecological breakdown. Under a global catastrophe of this scale, some or all of the Earth may be rendered uninhabitable as a result of extreme temperatures, severe weather events, an inability to grow crops, and an altered composition of the Earth's atmosphere. Although there is consensus on the attribution of recent climate change to human activity, and concern about future tipping points and feedback loops, there is no consensus on the likelihood of climate-induced collapse.
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  • 17 Oct 2022
Topic Review
Uniform Distribution (Continuous)
In probability theory and statistics, the continuous uniform distribution or rectangular distribution is a family of symmetric probability distributions. The distribution describes an experiment where there is an arbitrary outcome that lies between certain bounds. The bounds are defined by the parameters, a and b, which are the minimum and maximum values. The interval can be either be closed (eg. [a, b]) or open (eg. (a, b)). Therefore, the distribution is often abbreviated U (a, b), where U stands for uniform distribution. The difference between the bounds defines the interval length; all intervals of the same length on the distribution's support are equally probable. It is the maximum entropy probability distribution for a random variable X under no constraint other than that it is contained in the distribution's support.
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  • 17 Oct 2022
Topic Review
Google App Engine
Google App Engine (often referred to as GAE or simply App Engine) is a cloud computing platform as a service for developing and hosting web applications in Google-managed data centers. Applications are sandboxed and run across multiple servers. App Engine offers automatic scaling for web applications—as the number of requests increases for an application, App Engine automatically allocates more resources for the web application to handle the additional demand. Google App Engine primarily supports Go, PHP, Java, Python, Node.js, .NET, and Ruby applications, although it can also support other languages via "custom runtimes". The service is free up to a certain level of consumed resources and only in standard environment but not in flexible environment. Fees are charged for additional storage, bandwidth, or instance hours required by the application. It was first released as a preview version in April 2008 and came out of preview in September 2011.
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  • 17 Oct 2022
Topic Review
Lazarus
Lazarus is a free cross-platform visual integrated development environment (IDE) for rapid application development (RAD) using the Free Pascal compiler. Its goal is to provide an easy-to-use development environment for programmers developing with the Object Pascal language, which is as close as possible to Delphi. Software developers use Lazarus to create native-code console and graphical user interface (GUI) applications for the desktop, and also for mobile devices, web applications, web services, visual components and function libraries for a number of different platforms, including Mac, Linux and Windows. A project created by using Lazarus on one platform can be compiled on any other one which Free Pascal compiler supports. For desktop applications a single source can target Mac OS, Linux, and Windows, with little or no modification. An example is the Lazarus IDE itself, created from a single code base and available on all major platforms including the Raspberry Pi.
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  • 17 Oct 2022
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