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Reliable beacon transmission based MAC protocol for LR-WPANs over WLAN interferences

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第6期15卷 470-481页

作者： Ji-Hoon PARK byung-seo kim ITO Business Division Nongshim Data System Department of Computer and Information Communications Engineering Hongik University

The use of IEEE 802.15.4 standard based application systems has been rapidly increasing, for example, in medical services, sensor networks, public safety systems, and home automation systems. However, issues arise from the fact that IEEE 802.15.4 standard based low rate wireless personal area networks(LR-WPANs) use the same frequency bands as wireless local area networks(WLANs), and they interfere with each other. Based on past research on this issue, the interference has a more serious impact on LR-WPANs' performance than on WLANs' performance. In this paper we propose a method to improve LR-WPANs' performance while coexisting with WLANs, which is called the reliable beacon transmission based medium access control(MAC) protocol. Since the reliability of a beacon frame is important, in this method, only the beacon frame is transmitted in interference-free channels, and the data packets are transmitted in interfered channels instead of abandoning the channels altogether. This method increases the reliability of beacon frames as well as overall channel utilizations. The effectiveness of the proposed method was evaluated through extensive simulations, and this paper proves that this method improves the performance of IEEE 802.15.4 based wireless sensor networks(WSNs) over WLANs' interferences.

关键词： Low rate wireless personal area network(LR-WPAN) Interference Wireless local area network(WLAN) Beacon

Collision Observation-Based Optimization of Low-Power and Lossy IoT Network Using Reinforcement Learning

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Computers, Materials & Continua 2021年第4期67卷 799-814页

作者： Arslan Musaddiq Rashid Ali Jin-Ghoo Choi byung-seo kim Sung-Won kim Department of Information and Communication Engineering Yeungnam UniversityGyeongsan-si8541South Korea School of Intelligent Mechatronics Engineering Sejong UniversitySeoul05006South Korea Department of Software and Communications Engineering Hongik UniversitySeoul30016South Korea

The Internet of Things(IoT)has numerous applications in every domain,e.g.,smart cities to provide intelligent services to sustainable *** next-generation of IoT networks is expected to be densely deployed in a resource-constrained and lossy *** densely deployed nodes producing radically heterogeneous traffic pattern causes congestion and collision in the *** the medium access control(MAC)layer,mitigating channel collision is still one of the main challenges of future IoT ***,the standardized network layer uses a ranking mechanism based on hop-counts and expected transmission counts(ETX),which often does not adapt to the dynamic and lossy environment and impact *** ranking mechanism also requires large control overheads to update rank *** resource-constrained IoT devices operating in a low-power and lossy network(LLN)environment need an efficient solution to handle these *** learning(RL)algorithms like Q-learning are recently utilized to solve learning problems in LLNs devices like ***,in this paper,an RL-based optimization of dense LLN IoT devices with heavy heterogeneous traffic is *** proposed protocol learns the collision information from the MAC layer and makes an intelligent decision at the network *** proposed protocol also enhances the operation of the trickle timer algorithm.A Q-learning model is employed to adaptively learn the channel collision probability and network layer ranking states with accumulated reward *** on a simulation using Contiki 3.0 Cooja,the proposed intelligent scheme achieves a lower packet loss ratio,improves throughput,produces lower control overheads,and consumes less energy than other state-of-the-art mechanisms.

关键词： Internet of Things RPL MAC protocols reinforcement learning Q-learning

An Intelligent Forwarding Strategy in SDN-Enabled Named-Data IoV

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Computers, Materials & Continua 2021年第12期69卷 2949-2966页

作者： Asadullah Tariq Irfan ud din Rana Asif Rehman byung-seo kim Department of Computer Science The Superior UniversityLahore54000Pakistan National University of Computer and Emerging Sciences Chiniot-Faisalabad Campus35400Pakistan Department of Software and Communications Engineering Hongik UniversitySejong City30016Korea

Internet of Vehicles(IoV),a rapidly growing technology for efficient vehicular communication and it is shifting the trend of traditional Vehicular Ad Hoc Networking(VANET)towards *** centralized management of IoV endorses its uniqueness and suitability for the Intelligent Transportation System(ITS)safety *** Data Networking(NDN)is an emerging internet paradigm that fulfills most of the expectations of *** of the current IP internet architecture are the main motivation behind ***-Defined Networking(SDN)is another emerging networking paradigm of technology that is highly capable of efficient management of overall networks and transforming complex networking architectures into simple and manageable *** combination of the SDN controller,NDN,and IoV can be revolutionary in the overall performance of the *** storm,due to the broadcasting nature of NDN,is a critical issue in NDN based on *** speed and rapidly changing topology of vehicles in IoV creates disconnected link problem and add unnecessary transmission *** order to cop-up with the above-discussed problems,we proposed an efficient SDN-enabled forwarding mechanism in NDN-based IoV,which supports the mobility of the vehicle and explores the cellular network for the low latency control *** IoV environment,the concept of Edge Controller(EC)to maintain and manage the in-time and real-time vehicular topology is being introduced.A mathematical estimation model is also proposed in our work that assists the centralized EC and SDN to find not only the shortest and best path but also the most reliable and durable *** naming scheme and in-network caching property of the NDN nodes reduce the *** used ndnSIM and NS-3 for the simulation experiment along with SUMO for the environment *** results of NDSDoV illustrate significant performance in terms of availability with limited routing overhead,minimized delay,retransmissions,and in

关键词： Software-defined networking named-data networking internet of vehicles routing

Improving resource-constrained IoT device lifetimes by mitigating redundant transmissions across heterogeneous wireless multimedia of things

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Digital Communications and Networks 2022年第5期8卷 778-790页

作者： Muhammad Salah ud din Muhammad Atif Ur Rehman Rehmat Ullah Chan-Won Park Dae Ho kim byung-seo kim Department of Electronics&Computer Engineering Hongik UniversitySejong City30016South Korea Department of Computing&Mathematics Manchester Metropolitan University United Kingdom Cardiff School of Technologies Cardiff Metropolitan UniversityCardiffCF52YBUnited Kingdom Electronics and Telecommunications Research Institute Daejeon34129South Korea Department of Software and Communications Engineering Hongik UniversitySejong City30016South Korea

In Wireless Multimedia Sensor Networks(WMSNs),nodes capable of retrieving video,audio,images,and small scale sensor data,tend to generate immense traffic of various *** energy-efficient transmission of such a vast amount of heterogeneous multimedia content while simultaneously ensuring the quality of service and optimal energy consumption is ***,we propose a Power-Efficient Wireless Multimedia of Things(PE-WMoT),a robust and energy-efficient cluster-based mechanism to improve the overall lifetime of *** a PE-WMoT,nodes declare themselves Cluster Heads(CHs)based on available *** cluster formation and CH declaration processes are completed,the Sub-Cluster(SC)formation process triggers,in which application base nodes within close vicinity of each other organize themselves under the administration of a Sub-Cluster Head(SCH).The SCH gathers data from member nodes,removes redundancies,and forwards miniaturized data to its respective ***-WMoT adopts a fuzzy-based technique named the analytical hierarchical process,which enables CHs to select an optimal SCH among available SCs.A PE-WMoT also devises a robust scheduling mechanism between CH,SCH,and child nodes to enable collision-free data *** results revealed that a PE-WMoT significantly reduces the number of redundant packet transmissions,improves energy consumption of the network,and effectively increases network throughput.

关键词： Clustering WMSN WSN IoTs Resource-constrained Fuzzy AHP Sub clustering MAC Energy efficiency Network lifetime

一种针对无线多媒体业务的基于联合的缓存和调度的功率节省算法(英文)

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系统仿真学报 2009年第7期21卷 1805-1810页

作者：吴宇王杉习勇 byung-seo kim 国防科技大学长沙410073 Hongik University ShinanriKorea 339-701

一种有效的节省移动终端功率损耗的方法是在保证用户服务质量的前提下,尽可能的将无线网络接口(WNI)切换至休眠状态。然而我们发现,在多媒体业务流的分组到达间隔非常短的情况下,这个策略并不十分有效。提出了一个新的功率节省算法JBS... 详细信息

一种有效的节省移动终端功率损耗的方法是在保证用户服务质量的前提下,尽可能的将无线网络接口(WNI)切换至休眠状态。然而我们发现,在多媒体业务流的分组到达间隔非常短的情况下,这个策略并不十分有效。提出了一个新的功率节省算法JBS。通过在基站设置一个整形代理,对多媒体分组进行缓存,JBS很好的解决了分组到达间隔较短对功率节省性能的不利影响。进一步,通过使用我们设计的功率节省的机会调度器POS,JBS能够使系统中每个多媒体用户获得较高的吞吐量,并得到很好的分组时延性能。对JBS的性能进行了细致的仿真,结果表明JBS能够在保证用户服务质量的前提下有效降低WNI的功率损耗。

关键词：多媒体流功率节省服务质量无线调度

Optimal Resource Allocation Method for Device-to-Device Communication in 5G Networks

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Computers, Materials & Continua 2022年第4期71卷 1-15页

作者： Fahd N.Al-Wesabi Imran Khan Saleem Latteef Mohammed Huda Farooq Jameel Mohammad Alamgeer Ali M.Al-Sharafi byung seo kim Department of Computer Science King Khalid UniversityMuhayel AseerKSA Faculty of Computer and IT Sana’a UniversityYemen Department of Electrical Engineering University of Engineering and TechnologyPeshawarPakistan Department of Medical Instrumentation Techniques Engineering Electrical Engineering Technical CollegeMiddle Technical UniversityBaghdad10013Iraq Department of Information Systems King Khalid UniversityMayahel AseerKSA Department of Computer Science College of Computers and Information TechnologyUniversity of BishaKSA Department of Software and Communications Engineering Hongik UniversityKorea

With the rapid development of the next-generation mobile network,the number of terminal devices and applications is growing ***,how to obtain a higher data rate,wider network coverage and higher resource utilization in the limited spectrum resources has become the common research goal of ***-to-Device(D2D)communication technology and other frontier communication technologies have ***-to-Device communication technology is the technology that devices in proximity can communicate directly in cellular *** has become one of the key technologies of the fifth-generation mobile communications system(5G).D2D communication technology which is introduced into cellular networks can effectively improve spectrum utilization,enhance network coverage,reduce transmission delay and improve system throughput,but it would also bring complicated and various interferences due to reusing cellular resources at the same *** resource management is one of the most challenging and importing issues to give full play to the advantages of D2D *** resource allocation is an important factor that needs to be addressed in D2D ***,this paper proposes an optimization method based on the game-matching *** main idea is to model the optimization problem of the quality-of-experience based on user fairness and solve it through game-matching *** results show that the proposed algorithm effectively improved the resource allocation and utilization as compared with existing algorithms.

关键词： D2D communication resource allocation optimization networks

Solar Driven 15.7% Hydrogen Conversion by Harmony of Light Harvesting,Electron Transporting Bridge,and S-Defection in a Self-Assembled Microscale CuS/rGO/CP Photoanode

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Energy & Environmental Materials 2024年第3期7卷 190-201页

作者： Sujeong kim Boseok seo Hyerim Park Younghwan Im Jeong Yeon Do byung Sub Kwak Namgyu Son Minkyu kim Misook Kang Department of Chemistry College of Natural SciencesYeungnam UniversityGyeongsan Gyeongbuk 38541Korea School of Chemical Engineering Yeungnam UniversityGyeongsan Gyeongbuk 38541Korea Department of Energy and Hydrocarbon Chemistry Graduate School of EngineeringKyoto UniversityKyoto 615-8510Japan Korea Evaluation Institute of Industrial Technology(Keit) Cheomdan-Ro 8-GilDong-GuDaegu 41069Korea Korea Electric Power Research Institute(KEPRI)105 Munji-ro Yooseong-guDaejeon 34056Korea

CuS is an encouraging photoelectrode candidate that meets the essential requirements for efficient solar-to-hydrogen production,but it has not been thoroughly studied.A CuS light absorber layer is grown by the self-assembly of copper and sulfur precursors on a carbon paper(CP)***,rGO is introduced as a buffer layer to control the optical and electrical properties of the *** well-ordered microstructural arrangement suppresses the recombination loss of electrons and holes owing to enhanced charge-carrier generation,separation,and *** potential reaching 10 mA cm^(-2)in 1.0 M KOH solution is significantly lowered to 0.87 V,and the photocurrent density at 1.23 V is 94.7 mA cm^(-2).The computational result reveals that the potential-determining step is sensitive to O^(*)stability;the lower stability of O^(*)in the thin layer of CuS/rGO decreases the free-energy gap between the initial and final states of the potential-determining step,resulting in a lowering of the onset *** faradaic efficiency for the photoelectrochemical oxygen evolution reaction in the optimized 2CuS/1rGO/CP photoanode is 98.60%,and the applied bias photon-to-current and the solar-to-hydrogen efficiencies are 11.2%and 15.7%,respectively,and its ultra-high performance is maintained for 250 *** record-breaking achievement indices may be a trigger for establishing a green hydrogen economy.

关键词： 15.7%-solar to hydrogen density functional theory lower photopotential p-CuS/rGO/CP photoanode photoelectrochemical oxygen evolution

A Comprehensive Survey on Federated Learning in the Healthcare Area: Concept and Applications

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2239-2274页

作者： Deepak Upreti Eunmok Yang Hyunil kim Changho seo Department of Convergence Science Kongju National UniversityChungcheongnam-doGongju-si32588South Korea Department of Information Security Cryptologyand MathematicsKookmin UniversitySeoul02707South Korea Department of Information and Communication Engineering Chosun UniversityGwangju61452South Korea Basic Science Research Institution Kongju National UniversityChungcheongnam-doGongju-si32588South Korea

Federated learning is an innovative machine learning technique that deals with centralized data storage issues while maintaining privacy and *** involves constructing machine learning models using datasets spread across several data centers,including medical facilities,clinical research facilities,Internet of Things devices,and even mobile *** main goal of federated learning is to improve robust models that benefit from the collective knowledge of these disparate datasets without centralizing sensitive information,reducing the risk of data loss,privacy breaches,or data *** application of federated learning in the healthcare industry holds significant promise due to the wealth of data generated from various sources,such as patient records,medical imaging,wearable devices,and clinical research *** research conducts a systematic evaluation and highlights essential issues for the selection and implementation of federated learning approaches in *** evaluates the effectiveness of federated learning strategies in the field of *** offers a systematic analysis of federated learning in the healthcare domain,encompassing the evaluation metrics *** addition,this study highlights the increasing interest in federated learning applications in healthcare among scholars and provides foundations for further studies.

关键词： Federated learning artificial intelligence machine learning privacy healthcare

A Cu-Pd alloy catalyst with partial phase separation for the electrochemical CO_(2) reduction reaction

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Journal of Energy Chemistry 2024年第6期93卷 8-15,I0001页

作者： Gyeong Ho Han Jung Yong seo Minji Kang Myung-gi seo Youngheon Choi Soo Young kim Sang Hyun Ahn School of Chemical Engineering and Material Science Chung-Ang UniversitySeoul 06974Republic of Korea Lotte Chemical Institute of Technology Daejeon 34110Republic of Korea Department of Materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea

Cu catalysts can convert CO_(2) through an electrochemical reduction reaction into a variety of useful carbon-based ***,this capability provides an obstacle to increasing the selectivity for a single ***,we report a simple fabrication method for a Cu-Pd alloy catalyst for use in a membrane electrode assembly(MEA)-based CO_(2) electrolyzer for the electrochemical CO_(2) reduction reaction(ECRR)with high selectivity for CO *** the composition of the Cu-Pd alloy catalyst was fabricated at 6:4,the selectivity for CO increased and the production of multi-carbon compounds and hydrogen is *** a Cu-Pd alloy catalyst with 6:4 ratio as the cathode of the MEAbased CO_(2) electrolyzer showed a CO faradaic efficiency of 92.8%at 2.4 V_(cell).We assumed that these results contributed from the crystal planes on the surface of the Cu-Pd *** phases of the Cu-Pd alloy catalyst were partially separated through annealing to fabricate a catalyst with high selectivity for CO at low voltage and C_(2)H_4 at high *** results of CO-stripping testing confirmed that when Cu partially separates from the lattice of the Cu-Pd alloy,the desorption of~*CO is suppressed,suggesting that C-C coupling reaction is favored.

关键词： Cu-Pd catalyst Electrodeposition Electrochemical carbon dioxide reduction Partial phase separation Membrane electrode assembly-based electrolyzer