Research on power flux-density at the earth’s surface produced by emissions from the steerable beam of LEO constellation system by Ying HUANG, Wei LI, Chen JIAN, Kang YAN

“…The power flux-density (PFD) is an interference criterion for protecting terrestrial service systems from space service systems.A calculation method on the PFD produced by the emissions from the steerable beam of low earth orbit (LEO) constellation system was given, and thus a compliance determination algorithm of the limits of PFD under specific steering angle was presented.On this basis, a compliance determination algorithm of the limits of PFD based on elevation traversal was proposed.Combined with the characteristics of LEO constellation system, the conditions to simplify the calculation of maximum PFD of steerable beam were demonstrated.Taking the Starlink system as the typical scenario, the PFD produced by the gateway beam was analyzed, and the correctness of the proposed method was verified by comparison with the results published by SpaceX.The results showed that the PFD of the gateway beam of the Starlink system in Ka frequency band atelevations below 20° exceeded the limits given in Radio Regulations.…”
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Communication and navigation integration for LEO constellations:status, opportunities, and challenges by Yafei ZHAO, Bing YAN, Yaohua SUN, Mugen PENG

“…With the growing maturity of millimeter wave technology and high-throughput satellite communication technology, as well as the urgent need for global broadband communication services, the construction of LEO giant communication constellation has attracted great attention, and up to thousands of satellites have been deployed.A large number of LEO communication satellites have realized multiple and repeated coverage of high-frequency radio frequency signals on the ground.At the same time, ground communication resources provide a hardware platform for signal reception and create conditions for the development of integrated communication and navigation.The status quo, opportunities and challenges of the integrated LEO navigation constellation were discussed, and the differences of resources required by the integrated LEO navigation constellation and the global navigation satellite system were emphatically expounded.In terms of space segment, ground segment and user segment, the conclusions and prospects for future research were presented.…”
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Novel UWB communication pulse design method by LIN Zhi-yuan, WEI Ping

“…The comparison were presented for the bit error rate （BER） performance analyses of the pulse position modula- tion time hopping ultra wideband （PPM TH UWB） impulse radio （IR） communication system employing the iterative combination pulse or the second derivative Gaussian pulse in the additive white Gaussian noise （AWGN） channel, multi- ple user interference （MUI） and multiple path channel. …”
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Capture-aware bit-detecting M-ary tree protocol for RFID tag identification by Lijuan ZHANG, Mingqiu FAN, Lei LEI, Yong WANG, Daishu YUAN

“…In passive radio frequency identification (RFID) systems, the capture effect may occur that the reader is possible to successfully decode the strongest signal when multiple tags reply simultaneously.In this situation, the weaker signals will be covered resulting in a tag hidden problem which greatly affects the system performance.To solve the problem, a bit-detecting M-ary tree (BMT) protocol was proposed.First, a bit-detecting tag number estimation method was proposed to estimate the number of tags and group them with a few slots.Next, an M-ary tree protocol was developed to eliminate all the idle slots and identify tags quickly.At the same time, a hash muting strategy was given to mute the identified tags and label the hidden ones with small communication cost.Both theoretic analysis and simulation results demonstrate that BMT can effectively reduce the identification delay by at least 15%.…”
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Implementation of Low-Cost UHF RFID Reader Front-Ends with Carrier Leakage Suppression Circuit by Bin You, Bo Yang, Xuan Wen, Liangyu Qu

“…A new ultrahigh frequency radio frequency identification (UHF RFID) reader’s front-end circuit which is based on zero-IF, single antenna structure and composed of discrete components has been designed. …”
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Power allocation algorithm of full duplex cognitive relay network based on energy harvesting by Shibing ZHANG, Liuke HAN, Meijuan ZHANG

“…To alleviate the shortage of spectrum resources and improve the power utilization of cognitive radio networks,a resource allocation algorithm of full duplex cognitive relay networks with energy harvesting was proposed.In the algorithm,the coefficient for power splitting of the relay and the transmit power of the secondary users were jointly optimized to maximize the throughput of the secondary users under the interference to primary users and energy harvesting constraints.Since the optimization of the algorithm was non-convex,it was transformed into two sub-optimizations,the sub-optimization of the coefficient for power splitting and the sub-optimization of the power transmitted of secondary users,which were the solvable convex sub-optimizations.Then,the final solution of the original optimization was obtained with the iterative algorithm.Simulation results show that the throughput of the proposed algorithm,can obtain 2 times throughput of the networks with half-duplex power splitting algorithm and 1.5 times throughput of the networks with full-duplex time switching algorithm.…”
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La radionovela de ciencia ficción española: ‘Historias para imaginar’ by Alfonso Merelo Solá

“… Es prácticamente desconocido el hecho de que en los años del auge de la radio en España se serializaron algunas obras de ciencia ficción. …”
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Ficción televisiva y estereotipos (inter)nacionales : un acercamiento imagológico a El Ministerio del Tiempo (2015-2016) by Enrique Santos Unamuno

“…From an imagological perspective, this paper focuses on the first two seasons of El Ministerio del Tiempo, a TV series broadcasted in 2015-2016 by the Spanish Radio and Television Corporation (RTVE). First, we briefly introduce the basics and tenets of Imagology, a subfield of Comparative Literature (regardings issues as stereotype / imagotype, character, nation, effet de typique…), traditionally centered on literary texts but susceptible of being applied to other cultural objects (such as audiovisual fiction, which is our case). …”
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Two-step ranging based on energy detection for IR-UWB sensor networks by ZHANG Ting-ting1, ZHANG Qin-yu2, ZHANG Nai-tong1

“…In order to design a low computational and cost ranging method for the IR-UWB （impulse radio ultra wideband） wireless sensor network, a two-step DP （direct path） component TOA （time of arrival） estimation algorithm based on energy detection was proposed. …”
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Review on the research of the global emergency communication spectrum by Xiaoyong LIU, Xixi FAN, Lin ZHU, Yuanxin YAO

“…The construction of an emergency private network is the necessity of unified command and dispatch communications in rescue of disasters, emergency response, and major activity safeguard.It is an important communication means of public safety protection.With the rapid development of radio technology, the traditional narrowband emergency communication system is difficult to meet the needs of multimedia data, interconnection, anti-interference and other needs under the new situation.Digitization, broadband and ubiquity have become the inevitable trend of the development of emergency private networks.First of all, the technical system and development trend of emergency communication were summarized, the global emergency communication research framework were introduced, the frequency planning and current use status of the emergency private network in the United States, Europe, Asia-Pacific and other countries and regions were analyzed.Finally, combine with the current frequency planning, suggestions for the construction of China’s emergency private network from the aspects of technology trends, industrial development, frequency band selection, and construction mode were presented.…”
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Analysis of 5G NR coverage capability at 2.6 GHz by Xinkai CUI, Hao LI, Xiangchuan GAO, Huan YANG

“…The current research on 5G new air interface is mainly concentrated in the middle and high frequency bands.The low frequency band re-cultivation used by 4G is of great significance for 5G-scale contiguous networking,but there are few studies.On the basis of discussing the factors affecting the radio transmission capability,the urban outdoor non-line-of-sight propagation model of 3GPP TR38.901 was selected,and the current mainstream air interface parameters were used to simulate the multi-system main physical channel propagation capability.By comparing the coverage capabilities of the same physical channels in the 4G and 5G NR bands,the 5G NR primary channel coverage capability in the 2.6 GHz band can achieve contiguous coverage on the existing 4G basis.…”
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Googling the US Electoral Cycle, 2004-2016: South African Insights by Bhaso Ndzendze

“…Digital media is forecast for 21% of political ads, cable TV 14% and radio nearly 5%” (Adgate, 2019). This disproportional share for digital spending is indicative of what scholars have termed as the rise of computational politics, defined by one study as “the application of digital targeted-marketing technologies to election campaigns” (Chester and Montgomery, 2017: 1). …”
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IRCICA Library UHF RFID Solutions by Abdullah Topaloğlu

“…This article was written with the intention of informing our fellow colleagues about the implementation of UHF RFID (Ultra High Frequency Radio-Frequency Identification) which, we think, will be used by libraries all around the world in the future and sharing applications and findings of the archival and documentation section of IRCICA on the subject. …”
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Accurate range-based distributed localization of wireless sensor nodes using grey wolf optimizer by Nabil Abdelkader Nouri, Abdenacer Naouri, Sahraoui Dhelim

“…The present paper presents an Accurate Localization Scheme that utilizes Grey Wolf Optimization (GWO) and is based on the Radio Signal Strength (RSS) ranging technique. The efficiency of our technique has been proved through extensive simulations, showing a consistent improvement in localization accuracy ratios and a decrease in location errors while maintaining cost-effectiveness. …”
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A Semi-Stochastic Propagation Model for the Study of Beam Tilting in Cellular Systems by Konstantinos B. Baltzis

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Two-Step Frequency Estimation of GNSS Signal in High-Dynamic Environment by Chao Wu, Yafeng Li, Liyan Luo, Jian Xie, Ling Wang

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Efficient Sensor Localization Method with Classifying Environmental Sensor Data by Ae-cheoun Eun, Young-guk Ha

“…However, there is a problem in determining sensor locations from the RSS: radio signal interference occurs because of the presence of indoor obstacles. …”
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MEDIA APPROACH TO POVERTY ALLEVIATION PROGRAMMES IN CHIKUN LOCAL GOVERNMENT AREA OF KADUNA STATE by Emmanuel Jibb Adams

“…The study, recommends that all future anti-poverty programmes of the government must have provision for an adequate budget to utilize the rural media and communication strategies including face-to face and radio to publicize these programmes so that no one among the poor will be excluded. …”
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Sensing-then-transmission slot scheduling optimization for opportu-nistic spectrum access under the interference constraint of primary us-ers by Jing ZHANG, Yin LU, Xi-qi GAO, Fu-chun ZHENG

“…A sensing-then-transmission slot scheduling scheme for opportunistic spectrum access under the interference constraint of primary users (PU) was proposed.First,the throughput of the cognitive radio system (CRS) with channel handoff mechanism and the interference ratio to PU were deduced.An optimization model combined the sensing time and sensing period was also set up.Then,the optimal sensing time and sensing period were derived by maximizing the throughput of the CRS subject to both interference ratio and sensing qua ity constraints.Based on the analysis,a time slot scheduling scheme was finally proposed.The achievable maximum throughput of the CRS was derived too.Simulation results indicate that the proposed slot scheduling scheme can enhance the throughput of the CRS,and fit the changes of interference ratio and sensing quality constraints better.…”
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Uterine Cervix Cancer. Different Progress among Prevention, Early Diagnosis and Treatment by Víctor Manuel Medina Pérez, Rodolfo Arián Morales Yera, Liudmila Sierra Pérez

“…New therapeutic strategies focus on molecular targets, inmunotherapy and the combination of these and old treatments as chemio-radio-therapy. Once again the issue of economy in cancer treatment is present, new therapies are highly expensive. …”
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