Articles — Essay

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.

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.

The Art, Science, and Engineering of Programming is a new journal created with the goal of placing the wonderful art of programming in the map of scholarly works. Many academic journals and conferences exist that publish research related to programming, starting with programming languages, software engineering, and expanding to the whole Computer Science field. Yet, many of us feel that, as the field of Computer Science expanded, programming, in itself, has been neglected to a secondary role not worthy of scholarly attention. That is a serious gap, as much of the progress in Computer Science lies on the basis of computer programs, the people who write them, and the concepts and tools available to them to express computational tasks. The Art, Science, and Engineering of Programming aims at closing this gap by focusing primarily on programming: the art itself (programming styles, pearls, models, languages), the emerging science of understanding what works and what doesn’t work in general and in specific contexts, as well as more established engineering and mathematical perspectives. This is an example of and a guide to writing articles for The Art, Science, and Engineering of Programming.

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.

The Internet has become the broadest area in which to exchange information and communicate.Some use this function in a positive way, whilst others do so negatively. With the growth of the Internet, social networks have also grown. Social networks are used in different fields and for different proposes. They are used in higher education to enhance training and collaborative learning and exchange knowledge in an interaction environment. This paper aims at finding the 10 best universities by measuring the use of social networks in education.Universities are selected for this experiment from the Academic Influence Ranking website for the domain of computer science overall (type A) (for more information about the selected universities please visit this link: http://pubstat.org/).

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.

Ensayo El Celular

The accelerated rate of growth in the amount of web applications returns as a result an increase in the traffic that web servers must handle. This aggregated traffic, in addition to the demand of the clients to be served in a real time frame, leads to the requirement of a customized way to control web related resources. All processes of the web server are tied to the control that the OS scheduler has over them, and for the default settings, the scheduler is set to handle general purpose tasks instead of being optimized forweb serving purposes. To address this issue, the use of custom settings into the scheduler will allow the daemons needed to run a web page (such as Apache, PHP and a SQL DB) to be handled by the OS as efficiently as possible. The results of the test will be the comparison in performance of a web server for different settings on the Linux Scheduler.

Through the modification of the kernel on a Ubuntu system, we managed to solve the n-Queens problem after changing the default time-slice, swappiness, latency and wakeup-granularity to different values and testing the problem.