Abstract Today there are many wireless communication systems that meet the needs of users, however those systems remains a revolutions regarding the quality and security of service level. In this article, we discuss the comparison of the performance of various wireless communication systems such as WIFI, WIMAX, UMTS, HSDPA, GPRS, GSM, 3G and LTE using a multiple correspondence analysis (MCA) to classify and... Today there are many wireless communication systems that meet the needs of users, however those systems remains a revolutions regarding the quality and security of service level. In this article, we discuss the comparison of the performance of various wireless communication systems such as WIFI, WIMAX, UMTS, HSDPA, GPRS, GSM, 3G and LTE using a multiple correspondence analysis (MCA) to classify and identify each system by their strong and weak mechanisms in terms of performance based on frequency band, rate, range, access technology, mobility, latency, modulation type and transmission type, in the aim to intended the characteristics that can increase the relevance and quality of the wireless communication system. Read More Read Less

Abstract DEX (Decision EXpert) is a qualitative multi-criteria decision modeling methodology. DEX models are used to evaluate and analyze decision alternatives. An essential component of DEX models are decision rules, represented in terms of decision tables. Decision tables may contain many elementary decision rules and may be difficult to be understood by the decision maker. A more compact and comprehensible representation is... DEX (Decision EXpert) is a qualitative multi-criteria decision modeling methodology. DEX models are used to evaluate and analyze decision alternatives. An essential component of DEX models are decision rules, represented in terms of decision tables. Decision tables may contain many elementary decision rules and may be difficult to be understood by the decision maker. A more compact and comprehensible representation is obtained by converting elementary decision rules to complex rules. The DEXRule algorithm, which is currently implemented in software DEXi, has been found inefficient with large decision tables. This research is aimed at improving the efficiency of the DEX-Rule algorithm. We propose a novel algorithm, called jRule, which generates complex rules by specialization. According to performance analysis, jRule is indeed more efficient than DEXRule. The compactness of complex rules produced by both algorithms varies and there is no clear winner. Read More Read Less

Abstract Given the estimated number of stars and planets in our galaxy, the probability of existence of intelligent civilizations seems high. The first to indicate this was the Drake equation with the assumed default parameters. Yet, the actual observations have yet to reflect those expectations. This discrepancy corresponds to the so-called Fermi Paradox. Although many key factors about the likelihood of alien civilizations... Given the estimated number of stars and planets in our galaxy, the probability of existence of intelligent civilizations seems high. The first to indicate this was the Drake equation with the assumed default parameters. Yet, the actual observations have yet to reflect those expectations. This discrepancy corresponds to the so-called Fermi Paradox. Although many key factors about the likelihood of alien civilizations still remain largely unknown, new methods of estimating the probability are being proposed. Some of them use probability distributions and the Monte Carlo methods. In this paper we recalculate one of those - the Sandberg interpretation of the Drake equation, analyze the difference between the methods, their strengths and weaknesses. In the conclusion, we find that the probability distribution better reflects our ignorance about the properties of alien environments than the dot-product method. In our opinion, there are several ways to further improve the computational model based on the Drake equation using the AI methods, thus eliminating the problem with too small probabilities and introducing 3D views. What makes these analysis relevant, is not only the number of estimated civilizations in our galaxy and a probability that we encounter them in the near future. More important, these models enable estimation of the life-span of the human civilization. Unfortunately, there is a considerably high probability that it will be quite short. Read More Read Less