Television white spaces (TVWSs) refer to the unused part of the spectrum under the very high frequency (VHF) and ultra-high frequency (UHF) bands. TVWS are frequencies under licenced primary users (PUs) that are not being used and are available for secondary users (SUs). There are several ways of implementing TVWS in communications, one of which is the use of TVWS database (TVWSDB). The primary purpose of TVWSDB is to protect PUs from interference with SUs. There are several geolocation databases available for this purpose. However, it is unclear if those databases have the prediction feature that gives TVWSDB the capability of decreasing the number of inquiries from SUs. With this in mind, the authors present a reinforcement learning-based TVWSDB. Reinforcement learning (RL) is a machine learning technique that focuses on what has been done based on mapping situations to actions to obtain the highest reward. The learning process was conducted by trying out the actions to gain the reward instead of being told what to do. The actions may directly affect the rewards and future rewards. Based on the results, this algorithm effectively searched the most optimal channel for the SUs in query with the minimum search duration. This paper presents the advantage of using a machine learning approach in TVWSDB with an accurate and faster-searching capability for the available TVWS channels intended for SUs.
Hierarchical temporal memory (HTM) is a biomimetic sequence memory algorithm that holds promise for invariant representations of spatial and spatio-temporal inputs. This article presents a comprehensive neuromemristive crossbar architecture for the spatial pooler (SP) and the sparse distributed representation classifier, which are fundamental to the algorithm. There are several unique features in the proposed architecture that tightly link with the HTM algorithm. A memristor that is suitable for emulating the HTM synapses is identified and a new Z-window function is proposed. The architecture exploits the concept of synthetic synapses to enable potential synapses in the HTM. The crossbar for the SP avoids dark spots caused by unutil
... Show MoreIn this paper, an intelligent tracking control system of both single- and double-axis Piezoelectric Micropositioner stage is designed using Genetic Algorithms (GAs) method for the optimal Proportional-Integral-Derivative (PID) controller tuning parameters. The (GA)-based PID control design approach is a methodology to tune a (PID) controller in an optimal control sense with respect to specified objective function. By using the (GA)-based PID control approach, the high-performance trajectory tracking responses of the Piezoelectric Micropositioner stage can be obtained. The (GA) code was built and the simulation results were obtained using MATLAB environment. The Piezoelectric Micropositioner simulation model with th
... Show MoreAbstract: Polarization beam splitter (PBS) integrated waveguides are the key components in the receiver of quantum key distribution (QKD) systems. Their function is to analyze the polarization of polarized light and separate the transverse-electric (TE) and transverse-magnetic (TM) polarizations into different waveguides. In this paper, a performance study of polarization beam splitters based on horizontal slot waveguide has been investigated for a wavelength of . PBS based on horizontal slot waveguide structure shows a polarization extinction ratio for quasi-TE and quasi-TM modes larger than with insertion loss below and a bandwidth of . Also, the fabrication tolerance of the structure is analyzed.<
... Show MoreIn this work a model of a source generating truly random quadrature phase shift keying (QPSK) signal constellation required for quantum key distribution (QKD) system based on BB84 protocol using phase coding is implemented by using the software package OPTISYSTEM9. The randomness of the sequence generated is achieved by building an optical setup based on a weak laser source, beam splitters and single-photon avalanche photodiodes operating in Geiger mode. The random string obtained from the optical setup is used to generate the quadrature phase shift keying signal constellation required for phase coding in quantum key distribution system based on BB84 protocol with a bit rate of 2GHz/s.
في تعزيز بيئة الانتاج الرشيق استخدام اسلوب S -5
٠ اش١جخ ٗزفقث ٌٟبِ ٟجعبؾٌّا تٔبغٌا ٟف بقزخِ ٟئبنل ( ًئاضل بساحم ) توهم ىلع ءىضلا طٍلسحو بلارم ءادأ ىلع اهرٍثأحو تٍوهملا اهحاءارجإو تمذخخسملا اهحاٍومح ثٍح نم تٍئاضملا تبساحملا دبثبغؾٌا . اسبِٙٚ د ءبمٌلأ ٟمبٌّا ـؾف ٍٝػ ض١وشزٌا يلاخ ِٓ خ١ٔٛٔبمٌا سِٛلأبث خفشؼٌّا ءٛم ٟف دب٠شؾزٌا ًجمزغٌّا ٍٝػ حشظٔ ٌا خجعبؾٌّا ْا شؽبجٌا ظزٕزعاٚ ذٍجٌٍ ٞدبقزللاا َذمزٌا خٍغػ غفد ٟف ُٙغر خ١ئبنم ، خجعبؾٌّا ٟف خِذخزغٌّا خض٠ذؾٌا ت١ٌ
... Show Moreيعد تعزيز التجارة الدولية في مقدمة اهتمامات اي دولة ، فكل دولة تسعى الى تقديم خدمة مشروعات لتنمية الخدمات والبنى التحتية بوسائل عدة ، ومن اهمها قيامها بتمويل تجارتها الداخلية والخارجية مما يؤدي الى ازدهار وتحقيق التنمية والنمو المستدامين في تلك الدولة . ولكي تؤدي التجارة الدولية دوراً بارزاً في تحقيق النمو والتنمية المستدامين، لابد من توافر بيئة تجارية دولية مناسبة و نظام تجاري دولي مساند لعملية التنمية فا
... Show Moreبات الفساد ظاهرة عالمية تهدد المجتمعات وبقائها ، وبدت الانقسامات المجتمعية تتضاعف في البلدان التي ينتشر فيها الفساد بمختلف أنواعه وتسمياته ، حيث استكشفت الدراسة بأن التشريعات الجنائية حرصت على تقرير نظام عقابي خاص لمواجهة جرائم الفساد مما استوجب بنا بيان المظاهر القانونية للفساد السياسي المتمثل بالرشوة الدولية والرشوة الانتخابية لان الفساد لم يعد متعلقا بالجانب الاقتصادي فحسب بل امتد إلى الجوانب الأخرى
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