Articles — Essay

Linear regression is one of the most widely used statistical methods available today. It is used by data analysts and students in almost every discipline. However, for the standard ordinary least squares method, there are several strong assumptions made about data that is often not true in real world data sets. This can cause numerous problems in the least squares model. One of the most common issues is a model overfitting the data. Ridge Regression and LASSO are two methods used to create a better and more accurate model. I will discuss how overfitting arises in least squares models and the reasoning for using Ridge Regression and LASSO include analysis of real world example data and compare these methods with OLS and each other to further infer the benefits and drawbacks of each method.

Microlattice

Visualization is a descriptive way to ensure the audience attention and to make people better understand the content of a given topic. Nowadays, in the world of science and technology, visualization has become a necessity. However, it is a huge challenge to visualize varying amounts of data in a static or dynamic form. In this paper we describe the role, value and importance of visualization in maths and science. In particular, we are going to explain in details the benefits and shortages of visualization in three main domains: Mathematics, Programming and Big Data. Moreover, we will show the future challenges of visualization and our perspective how to better approach and face with the recent problems through technical solutions.

Here we discuss the path integral formalism for quantization of fields. The basic idea is reviewed and explained. This is completely based on the book ``Quantum Field Theory A Modern Introduction" by Michio Kaku. For calculation natural system of units is taken.

Es posible diseñar modelos en donde la variable dependiente posea característica cualitativas, ese es el caso que analizaremos en el presente trabajo, enfocándonos únicamente en el modelo LOGIT que nos brinda ciertas ventajas en comparación a un modelo lineal de probabilidad, estimada por mínimos cuadrados ordinarios(MCO) para lo cual resaltaremos dichas diferencias. Los modelos de regresión con respuesta cualitativa son modelos de regresión en los cuales la variable dependiente puede ser de naturaleza cualitativa, mientras que las variables independientes pueden ser cualitativas o cuantitativas, o una mezcla de las dos; por ejemplo, si se está estudiando la relación entre ingresos y el pagar o no impuesto de renta, la respuesta o regresada solo puede tomar dos valores (si paga impuesto de renta o no paga dicho impuesto); otros ejemplos en que la regresada es cualitativa son si la familia posee o no vivienda propia, se aprueba o pierde un curso, padece determinada enfermedad o no la padece. La variable cualitativa en estos tipos de modelos no tiene que restringirse simplemente a respuestas de sí o no, la variable respuesta puede tomar más de dos valores, ser tricotómica o politómica, también se establecen modelos en lo que la variable dependiente es de carácter ordinal o de carácter nominal, en donde no hay preestablecido ningún tipo de orden. En este trabajo se analizara el modelo LOGIT en donde la variable dependiente es de carácter binario o dicotómico (sí o no). (Green 2001) Se trata pues de adoptar una formulación no lineal que obligue a que los valores estimados estén entre 0 y 1 ya que, la regresión con una variable binaria dependiente Y modeliza la probabilidad de que Y = 1. La regresión LOGIT utiliza una función de distribución logística, su función de distribución de probabilidad da lugar a probabilidades ente 0 y 1, y presenta un crecimiento no lineal (con mayores incrementos en la parte central).

Created for Stanford Mathematics Camp 2016. A brief introduction to the Hopf Fibration for introductory topology students.

In mathematics, a rational number is any number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. Since q may be equal to 1, every integer is a rational number. The set of all rational numbers, often referred to as ”the rationals”, is usually denoted by a boldface Q (or blackboard bold , Unicode ); it was thus denoted in 1895 by Giuseppe Peano after quoziente, Italian for ”quotient”. The decimal expansion of a rational number always either terminates after a finite number of digits or begins to repeat the same finite sequence of digits over and over. Moreover, any repeating or terminating decimal represents a rational number. These statements hold true not just for base 10, but also for any other integer base (e.g. binary, hexadecimal). A real number that is not rational is called irrational. Irrational numbers include √2, , e, and . The decimal expansion of an irrational number continues without repeating. Since the set of rational numbers is countable, and the set of real numbers is uncountable, almost allreal numbers are irrational.

Human life has developed in many aspects since the evolution of computer started. The main function of creating new technologies is to make human life easier. New technologies are being invented everyday which creates limitless opportunities for developers to make use of these technologies to serve a specific purpose or task. The Advertising used to be print paper or TV ads. Today mobile and online video creates new ways to contact with customers. Today Ads are kind of the most popular online advertising market in the world and trading ad spaces over the Internet. Currently the social online ads like Facebook and YouTube have some preferred set of users they wish to reach by showing their ads but some cases force the users to watch their Advertising. Ethan Zuckerman wad created the first pop-up advertising on the web was 15-Aug-2014. The pop-up advertising most using in the pc application and browser, and APPs for smartphone. The small internet windows that pop up on your screen can be useful, annoying or dangerous often used by advertisers to get your attention or by viruses to trick you into clicking on them. This guide gives them basic information about your identity. Some dangerous pop-up can leak your private information like your name, number, credit card member, and etc. In this paper we sum up, all these facts contribute to show how danger the pop-up advertising with developing new pop-up advertising to leak the user identity.

As of this writing, the algorithm employed for difficulty adjustment in the CryptoNote reference code is known by the Monero Research Lab to be flawed. We describe and illustrate the nature of the flaw and recommend a solution. By dishonestly reporting timestamps, attackers can gain disproportionate control over network difficulty. We verify this route of attack by auditing the CryptoNote reference difficulty adjustment code, which, we reimplement in the Python programming language. We use a stochastic model of blockchain growth to test the CryptoNote reference difficulty formula against the more traditional Bitcoin difficulty formula. This allows us to test our difficulty formula against various hash rate scenarios. This research bulletin has not undergone peer review, and reflects only the results of internal investigation.