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Topic Review
Opaque Forest Problem
In computational geometry, the opaque forest problem can be stated as follows: "Given a convex polygon C in the plane, determine the minimal forest T of closed, bounded line segments such that every line through C also intersects T". T is said to be the opaque forest, or barrier of C. C is said to be the coverage of T. While any forest that covers C is a barrier of C, we wish to find the one with shortest length. It may be the case that T is constrained to be strictly interior or exterior to C. In this case, we specifically refer to a barrier as interior or exterior. Otherwise, the barrier is assumed to have no constraints on its location.
  • 1.2K
  • 08 Oct 2022
Topic Review
Map Database Management
Map database management systems are software programs designed to efficiently store and recall spatial information. They are widely used in localization and navigation, especially in automotive applications. Moreover, they are playing an increasingly important role in the emerging areas of location-based services, active safety functions and advanced driver-assistance systems. Common to these functions is the requirement for an on-board map database that contains information describing the road network. When designed well, a map database enables the rapid indexing and lookup of a large amount of geographic data.
  • 1.2K
  • 15 Nov 2022
Topic Review
IoT and Machine Learning
Machine learning (ML) is a powerful tool that delivers insights hidden in Internet of Things (IoT) data. These hybrid technologies work smartly to improve the decision-making process in different areas such as education, security, business, and the healthcare industry. ML empowers the IoT to demystify hidden patterns in bulk data for optimal prediction and recommendation systems. Healthcare has embraced IoT and ML so that automated machines make medical records, predict disease diagnoses, and, most importantly, conduct real-time monitoring of patients. Individual ML algorithms perform differently on different datasets. Due to the predictive results varying, this might impact the overall results. The variation in prediction results looms large in the clinical decision-making process. Therefore, it is essential to understand the different ML algorithms used to handle IoT data in the healthcare sector.
  • 1.2K
  • 16 Jun 2021
Topic Review
Local Zeta-Function
In number theory, the local zeta function Z(V, s) (sometimes called the congruent zeta function) is defined as where Nm is the number of points of V defined over the mth cyclotomic field extension Fqm of Fq, and V is a non-singular n-dimensional projective algebraic variety over the field Fq with q elements. By the variable transformation u = q−s, then it is defined by as the formal power series of the variable [math]\displaystyle{ u }[/math]. Equivalently, the local zeta function sometimes is defined as follows: In other word, the local zeta function Z(V, u) with coefficients in the finite field Fq is defined as a function whose logarithmic derivative generates the numbers Nm of the solutions of equation, defining V, in the m degree extension Fqm.
  • 1.2K
  • 21 Oct 2022
Topic Review
Augmented Reality in Primary School Mathematics
Active learning, a student-centered approach, engages students in the learning process and requires them to solve problems using educational activities that enhance their learning outcomes. Augmented Reality (AR) has revolutionized the field of education by creating an intuitive environment where real and virtual objects interact, thereby facilitating the understanding of complex concepts. 
  • 1.2K
  • 23 Nov 2023
Topic Review
Classic Empire
Empire (or Classic Empire) is a 1977 turn-based wargame with simple rules. The game was conceived by Walter Bright starting in 1971, based on various war movies and board games, notably Battle of Britain and Risk. The game was ported to many platforms in the 1970s and 80s. Several commercial versions were also released, often adding basic graphics to the originally text-based user interface. The basic gameplay is strongly reminiscent of several later games, notably Civilization.
  • 1.2K
  • 11 Nov 2022
Topic Review
Bunyakovsky Conjecture
The Bunyakovsky conjecture (or Bouniakowsky conjecture) gives a criterion for a polynomial [math]\displaystyle{ f(x) }[/math] in one variable with integer coefficients to give infinitely many prime values in the sequence[math]\displaystyle{ f(1), f(2), f(3),\ldots. }[/math] It was stated in 1857 by the Russian mathematician Viktor Bunyakovsky. The following three conditions are necessary for [math]\displaystyle{ f(x) }[/math] to have the desired prime-producing property: Bunyakovsky's conjecture is that these conditions are sufficient: if [math]\displaystyle{ f(x) }[/math] satisfies (1)-(3), then [math]\displaystyle{ f(n) }[/math] is prime for infinitely many positive integers [math]\displaystyle{ n }[/math].
  • 1.2K
  • 31 Oct 2022
Topic Review
De Rham Curve
In mathematics, a de Rham curve is a certain type of fractal curve named in honor of Georges de Rham. The Cantor function, Cesàro curve, Minkowski's question mark function, the Lévy C curve, the blancmange curve and the Koch curve are all special cases of the general de Rham curve.
  • 1.2K
  • 01 Nov 2022
Topic Review
COHERENS
COHERENS is an open-source hydrodynamic computer model for shallow waters. It was developed in the 1990s by the Royal Belgian Institute of Natural Sciences (RBINS). The name COHERENS is an acronym of COupled Hydrodynamical Ecological model for REgioNal Shelf seas. COHERENS can be used in 1D, 2D or 3D mode and can model both salt waters such as coastal and shelf seas and freshwater basins such as lakes. Applications of the model include obtaining a better understanding of shallow water systems and managing pollution.
  • 1.2K
  • 19 Oct 2022
Topic Review
Virtual Reality in the Rehabilitation
Over the past two decades, virtual reality technology (VRT)-based rehabilitation has been increasingly examined and applied to assist patient recovery in the physical and cognitive domains. The advantages of the use of VRT in the neurorehabilitation field consist of the possibility of training an impaired function as a way to stimulate neuron reorganization (to maximize motor learning and neuroplasticity) and restoring and regaining functions and abilities by interacting with a safe and nonthreatening yet realistic virtual reality environment (VRE). Furthermore, VREs can be tailored to patient needs and provide personalized feedback on performance. VREs may also support cognitive training and increases patient motivation and enjoyment. Despite these potential advantages, there are inconclusive data about the usefulness of VRT in neurorehabilitation settings, and some issues on feasibility and safety remain to be ascertained for some neurological populations.
  • 1.2K
  • 07 May 2021
Topic Review
Driver Drowsiness Detection
Drowsy driving is a widespread cause of traffic accidents, especially on highways. It has become an essential task to seek an understanding of the situation in order to be able to take immediate remedial actions to detect driver drowsiness and enhance road safety.
  • 1.2K
  • 25 Sep 2023
Topic Review
Training, Test, and Validation Sets
In machine learning, the study and construction of algorithms that can learn from and make predictions on data is a common task. Such algorithms work by making data-driven predictions or decisions,:2 through building a mathematical model from input data. The data used to build the final model usually comes from multiple datasets. In particular, three data sets are commonly used in different stages of the creation of the model. The model is initially fit on a training dataset, that 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 neural net or a naive Bayes classifier) is trained on the training dataset using a supervised learning method (e.g. gradient descent or stochastic gradient descent). In practice, the training dataset often consist of pairs of an input vector and the corresponding "answer" vector (or scalar), which is commonly denoted as the target (or label). The current model is run with the training dataset and produces a result, which is then compared with the target, for each input vector in the training dataset. 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 dataset called the validation dataset. The validation dataset provides an unbiased evaluation of a model fit on the training dataset while tuning the model's hyperparameters (e.g. the number of hidden units in a neural network). Validation datasets can be used for regularization by early stopping: stop training when the error on the validation dataset increases, as this is a sign of overfitting to the training dataset. 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 overfitting has truly begun. Finally, the test dataset is a dataset used to provide an unbiased evaluation of a final model fit on the training dataset.. When the data in the test dataset has never been used in training (for example in cross-validation), the test dataset is also called a holdout dataset.
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  • 03 Nov 2022
Topic Review
Medical Expenditure Panel Survey
{{Multiple issues| The Medical Expenditure Panel Survey (MEPS) is a family of surveys intended to provide nationally representative estimates of health expenditure, utilization, payment sources, health status, and health insurance coverage among the noninstitutionalized, nonmilitary population of the United States . This series of government-produced data sets can be used to examine how individuals interact with the medical care system in the United States. MEPS is administered by the Agency for Healthcare Research and Quality (AHRQ) in three components: the core Household Component, the Insurance/Employer Component, and the Medical Provider Component. Only the Household Component is available for download on the Internet. These components provide comprehensive national estimates of health care use and payment by individuals, families, and any other demographic group of interest.
  • 1.2K
  • 17 Oct 2022
Topic Review
Pseudonymity
Pseudonymity, a word derived from pseudonym, meaning 'false name', is a state of disguised identity. The pseudonym identifies a holder, that is, one or more human beings who possess but do not disclose their true names (that is, legal identities). Most pseudonym holders use pseudonyms because they wish to remain anonymous, but anonymity is difficult to achieve and is often fraught with legal issues. True anonymity requires unlinkability, such that an attacker's examination of the pseudonym holder's message provides no new information about the holder's true name.
  • 1.2K
  • 14 Nov 2022
Topic Review
Web-Based Serious Games and Accessibility
The entries consolidate the main concepts about serious web-based games; the characterization of serious games, accessibility, accessibility guidelines and types of disabilities, and the findings found after reviewing the literature.
  • 1.2K
  • 18 Nov 2020
Topic Review
Universal Photonic Biosensors, Emerging Pathogens
To provide resiliency against pandemics, new types of universal biosensors that can be rapidly adapted and deployed on a large scale for the detection of new pathogens and new variants of known pathogens and exhibit real-time detection with LOD as low as a few target molecules need to be developed. Photonic biosensors, which provide optical signal amplification and can be mass-produced by existing semiconductor foundries, offer a promising platform, which is in principle amenable to multiplexing with spectroscopic and electrochemical detection techniques. However, to reach sub-fM detection levels, photonic biosensors typically have had to be engineered to support ultra-high-Q trapped modes.
  • 1.2K
  • 13 Sep 2021
Topic Review
Aperiodic Frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also referred to as temporal frequency, which emphasizes the contrast to spatial frequency and angular frequency. Frequency is measured in units of hertz (Hz) which is equal to one occurrence of a repeating event per second. The period is the duration of time of one cycle in a repeating event, so the period is the reciprocal of the frequency. For example: if a newborn baby's heart beats at a frequency of 120 times a minute (2 hertz), its period, T, — the time interval between beats—is half a second (60 seconds divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light.
  • 1.2K
  • 11 Nov 2022
Topic Review
Lieb–Oxford Inequality
In quantum chemistry and physics, the Lieb–Oxford inequality provides a lower bound for the indirect part of the Coulomb energy of a quantum mechanical system. It is named after Elliott H. Lieb and Stephen Oxford. The inequality is of importance for density functional theory and plays a role in the proof of stability of matter.
  • 1.2K
  • 05 Dec 2022
Topic Review
Kune
Kune is a free/open source distributed social network focused on collaboration rather than just on communication. That is, it focuses on online real-time collaborative editing, decentralized social networking and web publishing, while focusing on workgroups rather than just on individuals. It aims to allow for the creation of online spaces for collaborative work where organizations and individuals can build projects online, coordinate common agendas, set up virtual meetings, publish on the web, and join organizations with similar interests. It has a special focus on Free Culture and social movements needs. Kune is a project of the Comunes Collective.
  • 1.2K
  • 31 Oct 2022
Topic Review
List of Matrices
This page lists some important classes of matrices used in mathematics, science and engineering. A matrix (plural matrices, or less commonly matrixes) is a rectangular array of numbers called entries. Matrices have a long history of both study and application, leading to diverse ways of classifying matrices. A first group is matrices satisfying concrete conditions of the entries, including constant matrices. An important example is the identity matrix given by Further ways of classifying matrices are according to their eigenvalues or by imposing conditions on the product of the matrix with other matrices. Finally, many domains, both in mathematics and other sciences including physics and chemistry have particular matrices that are applied chiefly in these areas.
  • 1.2K
  • 29 Nov 2022
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