117,024 research outputs found

    An M-QAM Signal Modulation Recognition Algorithm in AWGN Channel

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    Computing the distinct features from input data, before the classification, is a part of complexity to the methods of Automatic Modulation Classification (AMC) which deals with modulation classification was a pattern recognition problem. Although the algorithms that focus on MultiLevel Quadrature Amplitude Modulation (M-QAM) which underneath different channel scenarios was well detailed. A search of the literature revealed indicates that few studies were done on the classification of high order M-QAM modulation schemes like128-QAM, 256-QAM, 512-QAM and1024-QAM. This work is focusing on the investigation of the powerful capability of the natural logarithmic properties and the possibility of extracting Higher-Order Cumulant's (HOC) features from input data received raw. The HOC signals were extracted under Additive White Gaussian Noise (AWGN) channel with four effective parameters which were defined to distinguished the types of modulation from the set; 4-QAM~1024-QAM. This approach makes the recognizer more intelligent and improves the success rate of classification. From simulation results, which was achieved under statistical models for noisy channels, manifest that recognized algorithm executes was recognizing in M-QAM, furthermore, most results were promising and showed that the logarithmic classifier works well over both AWGN and different fading channels, as well as it can achieve a reliable recognition rate even at a lower signal-to-noise ratio (less than zero), it can be considered as an Integrated Automatic Modulation Classification (AMC) system in order to identify high order of M-QAM signals that applied a unique logarithmic classifier, to represents higher versatility, hence it has a superior performance via all previous works in automatic modulation identification systemComment: 18 page

    SPH-EXA: Enhancing the Scalability of SPH codes Via an Exascale-Ready SPH Mini-App

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    Numerical simulations of fluids in astrophysics and computational fluid dynamics (CFD) are among the most computationally-demanding calculations, in terms of sustained floating-point operations per second, or FLOP/s. It is expected that these numerical simulations will significantly benefit from the future Exascale computing infrastructures, that will perform 10^18 FLOP/s. The performance of the SPH codes is, in general, adversely impacted by several factors, such as multiple time-stepping, long-range interactions, and/or boundary conditions. In this work an extensive study of three SPH implementations SPHYNX, ChaNGa, and XXX is performed, to gain insights and to expose any limitations and characteristics of the codes. These codes are the starting point of an interdisciplinary co-design project, SPH-EXA, for the development of an Exascale-ready SPH mini-app. We implemented a rotating square patch as a joint test simulation for the three SPH codes and analyzed their performance on a modern HPC system, Piz Daint. The performance profiling and scalability analysis conducted on the three parent codes allowed to expose their performance issues, such as load imbalance, both in MPI and OpenMP. Two-level load balancing has been successfully applied to SPHYNX to overcome its load imbalance. The performance analysis shapes and drives the design of the SPH-EXA mini-app towards the use of efficient parallelization methods, fault-tolerance mechanisms, and load balancing approaches.Comment: arXiv admin note: substantial text overlap with arXiv:1809.0801

    Lisp, Jazz, Aikido -- Three Expressions of a Single Essence

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    The relation between Science (what we can explain) and Art (what we can't) has long been acknowledged and while every science contains an artistic part, every art form also needs a bit of science. Among all scientific disciplines, programming holds a special place for two reasons. First, the artistic part is not only undeniable but also essential. Second, and much like in a purely artistic discipline, the act of programming is driven partly by the notion of aesthetics: the pleasure we have in creating beautiful things. Even though the importance of aesthetics in the act of programming is now unquestioned, more could still be written on the subject. The field called "psychology of programming" focuses on the cognitive aspects of the activity, with the goal of improving the productivity of programmers. While many scientists have emphasized their concern for aesthetics and the impact it has on their activity, few computer scientists have actually written about their thought process while programming. What makes us like or dislike such and such language or paradigm? Why do we shape our programs the way we do? By answering these questions from the angle of aesthetics, we may be able to shed some new light on the art of programming. Starting from the assumption that aesthetics is an inherently transversal dimension, it should be possible for every programmer to find the same aesthetic driving force in every creative activity they undertake, not just programming, and in doing so, get deeper insight on why and how they do things the way they do. On the other hand, because our aesthetic sensitivities are so personal, all we can really do is relate our own experiences and share it with others, in the hope that it will inspire them to do the same. My personal life has been revolving around three major creative activities, of equal importance: programming in Lisp, playing Jazz music, and practicing Aikido. But why so many of them, why so different ones, and why these specifically? By introspecting my personal aesthetic sensitivities, I eventually realized that my tastes in the scientific, artistic, and physical domains are all motivated by the same driving forces, hence unifying Lisp, Jazz, and Aikido as three expressions of a single essence, not so different after all. Lisp, Jazz, and Aikido are governed by a limited set of rules which remain simple and unobtrusive. Conforming to them is a pleasure. Because Lisp, Jazz, and Aikido are inherently introspective disciplines, they also invite you to transgress the rules in order to find your own. Breaking the rules is fun. Finally, if Lisp, Jazz, and Aikido unify so many paradigms, styles, or techniques, it is not by mere accumulation but because they live at the meta-level and let you reinvent them. Working at the meta-level is an enlightening experience. Understand your aesthetic sensitivities and you may gain considerable insight on your own psychology of programming. Mine is perhaps common to most lispers. Perhaps also common to other programming communities, but that, is for the reader to decide..

    Numerical simulation of electric signal in the cyber-physical immunosensor system on rectangular lattice in R package

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    Проведено чисельне моделювання електричного сигналу з перетворювача в кіберфізичній імуносенсорній системі на прямокутній решітці з використанням диференціальних рівнянь із запізненням за допомогою пакета R. Описано функціональні можливості пакета R як середовища програмування для статистичного аналізу даних, наведено корисні сайти, списки посилань і документація пакета R. У вигляді таблиці представлено назви параметрів моделі імуносенсора на прямокутній решітці з використанням диференціальних рівнянь із запізненням та їх числові значення в пакеті R. Реалізовано комп’ютерну програму «Чисельний аналіз електричного сигналу з перетворювача, який характеризує кількість флуоресціюючих пікселів в імуносенсорі на прямокутній решітці з використанням диференціальних рівнянь із запізненням». Розроблена комп’ютерна програма дає змогу провести дослідження стійкості імуносенсорних систем, які широко використовуються для отримання діагностичної інформації з метою оцінювання критичних станів при серцево-судинних захворюваннях, величини інсуліну при вимірюванні величини глюкози в крові та виявлення кількісних показників у деяких фармацевтичних сполуках. Наведено фрагмент лістингу комп’ютерної програми в пакеті R для отримання електричного сигналу з перетворювача, який характеризує кількість флуоресціюючих пікселів у кіберфізичній імуносенсорній системі на прямокутній решітці з використанням диференціальних рівнянь із запізненням. Проведено чисельне моделювання для електричного сигналу з перетворювача в імуносенсорі на прямокутній решітці з використанням диференціальних рівнянь із запізненням. Проаналізовано зміни отриманого електричного сигналу, які відповідають кількості флуоресціюючих пікселів у кіберфізичній імуносенсорній системі. Обгрунтовано використання пакета R як вільнопоширюваного програмного забезпечення з графічною візуалізацією результатів аналізу.The numerical simulation of electric signal from the converter in the cyber-physical immunosensor system on rectangular lattice using differential equations with delay by means of R package is carried out in this paper. The functional features of R package as a programming environment for statistical data analysis are described, useful sites, references lists and documentation of R package are given. The names of parameters of the immunosensor model on rectangular lattice using the differential equations with delay and their numerical values in the package R are presented in the form of the table. The computer program «Numerical analysis of the electrical signal from the converter that characterizes the number of fluorescing pixels in the immunosensor on rectangular lattice using delayed differential equations» is implemented. The developed computer program makes it possible to carry out the investigation of the stability of immunosensory systems, which are widely used to obtain diagnostic information in order to evaluate critical states of cardiovascular disease, insulin values while measuring blood glucose values and identify quantitative indicators in some рharmaceutics compounds. The fragment of computer program listing in R package for obtaining the electrical signal from converter characterizing the number of fluorescent pixels in cyber-physical immunosensor system on rectangular lattice using delayed differential equations is presented. Numerical simulation for the electric signal from the converter in the immunosensor on rectangular lattice using the delayed differential equations is carried out. The changes of the received electrical signal corresponding to the number of fluorescent pixels in the cyber-physical immunosensory system are analyzed. The use of R package as a freely distributed software with graphical visualization of the analysis results is substantiated
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