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Bilayer expurgated LDPC codes with uncoded relaying

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Digital communications and Networks 2017年第3期3卷 176-179页

作者： Md. Noor-A-Rahim Nan Zhang Sk. Md. Rabiul Islam Y.L. Guan Centre for Infocomm Technology (INFINITUS) Nanyang Technological University Singapore Institute for TelecommunicationsResearch University of South Australia Adelaide Australia dept.of eleetronics and communication engineering Khulna University of Engineering & Technology Bangladesh

Bilayer low-density parity-check (LDPC) codes are an effective coding technique for decode-and-forward relaying, where the relay forwards extra parity bits to help the destination to decode the source bits correctly. In the existing bilayer coding scheme, these parity bits are protected by an error correcting code and assumed reliably available at the receiver. We propose an uncoded relaying scheme, where the extra parity bits are forwarded to the destination without any protection. Through density evolution analysis and simulation results, we show that our proposed scheme achieves better performance in terms of bit erasure probability than the existing relaying scheme. In addition, our proposed scheme results in lower complexity at the relay.

关键词： Bilayer codes LDPC codes Density evolution Decode-and-forward relaying

Machine vision for drill string slip status detection

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Petroleum Research 2022年第1期7卷 115-122页

作者： Sunil Kumar Khare dept.of Petroleum engineering and Earth Sciences University of Petroleum and Energy StudiesDehradunUK248007India

Slip status of drill string is system generated binary value computed by comparison of sensor generated real time hook load value with a minimum threshold value of hook load stored in measurement system.This research article describes a novel method of slip status detection by machine vision technology which helps overcome the constraints of slip status detection with legacy measurement method.It also helps improve the real time drilling data quality and optimize and automate drilling operations.A method to detect drill string slip status with high-resolution digital camera installed on mast near rig floor is described along with backend vision processing and communication modules,which generate binary values of slip status.The binary values are transferred in real time to drilling measurement system of rig to compute other drilling parameters like bit depth,hole depth and stand counters.This method includes deploying active optical sensors at the rig floor,obtaining 1-D,2-D,or 3D image data,and processing it to obtain the status of drill string.Reliable measurement of slip status by machine vision helps reduce non-productive time(NPT)by reliable real time surveillance of drilling operations.

关键词： Oil and gas Machine vision Camera Slip-status Rig Drilling Rotary table NPT Drilling fluid Drill pipe

Continuous-wave operation of 1550 nm low-threshold triple-lattice photonic-crystal surface-emitting lasers

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Light(Science & Applications) 2024年第3期13卷 446-453页

作者： Ziye Wang Xia Liu Pinyao Wang Huanyu Lu Bo Meng Wei Zhang Lijie Wang Yanjing Wang Cunzhu Tong State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Center of Materials Science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China Central Research Institute Planning dept 2012 LabsHuawei Technologies Company Ltd.Shenzhen 518129China

Benefitting from narrow beam divergence,photonic crystal surface-emitting lasers are expected to play an essential role in the ever-growing fields of optical communication and light detection and ranging.Lasers operating with 1.55μm wavelengths have attracted particular attention due to their minimum fiber loss and high eye-safe threshold.However,high interband absorption significantly decreases their performance at this 1.55μm wavelength.Therefore,stronger optical feedback is needed to reduce their threshold and thus improve the output power.Toward this goal,photonic-crystal resonators with deep holes and high dielectric contrast are often used.Nevertheless,the relevant techniques for high-contrast photonic crystals inevitably complicate fabrication and reduce the final yield.In this paper,we demonstrate the first continuous-wave operation of 1.55μm photonic-crystal surface-emitting lasers by using a‘triple-lattice photonic-crystal resonator’,which superimposes three lattice point groups to increase the strength of in-plane optical feedback.Using this geometry,the in-plane 180°coupling can be enhanced threefold compared to the normal single-lattice structure.Detailed theoretical and experimental investigations demonstrate the much lower threshold current density of this structure compared to‘single-lattice’and‘double-lattice’photonic-crystal resonators,verifying our design principles.Our findings provide a new strategy for photonic crystal laser miniaturization,which is crucial for realizing their use in future high-speed applications.

关键词： resonator crystal lattice

Analytical Design of Fractional Order Proportional Integral Derivative Controller and Fuzzy Proportional Integral Derivative Controller for High Order System

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Journal of Harbin Institute of Technology(New Series) 2013年第4期20卷 21-25页

作者： Chun-Yang Wang Tong Yi Xiao-Yu Zhao Yao-Wu Shi dept.of Electronic and Information engineering Changchun University of Science and Technology dept.of communication engineering Jilin University

In this paper,three tuning methods of the integer order proportional integral derivative(IOPID)controller,the fuzzy proportional integral derivative(FPID)controller and the fractional order proportional integral derivative(FOPID)controller for high order system are presented respectively.Both IOPID controller and FOPID controller designed by the two tuning methods can satisfy all the three specifications proposed,which can guarantee the desired control performance and the robustness of the high order system to the loop gain variations.From the simulation results,the three controllers meet the dynamic performance requirements of high order system.Moreover,the FOPID controller,with the shortest overshoot and adjustment time,outperforms the IOPID controller and the FPID controller for the high order system.

关键词： IOPID controller FPID controller FOPID controller High order system

Study and application of reinforcement learning based on DAI in cooperative strategy of robot soccer

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Journal of Harbin Institute of Technology(New Series) 2009年第4期16卷 513-519页

作者：郭琦张达志杨永田 dept.of Mathematics Harbin Institute of Technology dept.of Computer Science and engineering Harbin Engineering University

A dynamic cooperation model of multi-agent is established by combining reinforcement learning with distributed artificial intelligence(DAI),in which the concept of individual optimization loses its meaning because of the dependence of repayment on each agent itself and the choice of other agents.Utilizing the idea of DAI,the intellectual unit of each robot and the change of task and environment,each agent can make decisions independently and finish various complicated tasks by communication and reciprocation between each other.The method is superior to other reinforcement learning methods commonly used in the multi-agent system.It can improve the convergence velocity of reinforcement learning,decrease requirements of computer memory,and enhance the capability of computing and logical ratiocinating for agent.The result of a simulated robot soccer match proves that the proposed cooperative strategy is valid.

关键词：机器人足球比赛强化学习基础加固分布式人工智能作战应用计算机内存多代理

Finding an Effective Distance Between T-Cell and B-Cell Using S/W ARQ in an Immune System communication

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China communications 2020年第1期17卷 174-185页

作者： Sanjit Ningthoujam Tekcham Chingkheinganba Swarnendu K Chakraborty dept.of Computer Science and engineering NIT Arunachal Pradesh

In this paper,we present the effective distance between T-cell and B-cell in an immune system using Stop and Wait(S/W)Automatic Repeat Request(ARQ).The concentration of the molecules can be increased by increasing the transmitting number of molecules but it may reduce the performance of communication due to higher collision or interference with other molecules.It is also reported in the literature that the concentration of the emitted molecules reduces if the distance from Transmitter(Tx)to Receiver(Rx)increases.Thus,this paper mainly focuses on enhancing the receiver’s capture probability and higher successful complete transmission of the desired molecules by obtaining the effective distance from T-cell to B-cell.In order to find the effective distance,T-cell transmits the molecules 1(Interleukins-2)to B-cell,upon successful reception of molecules 1,antibodies(molecules 2)transmit back to T-cell.Then,the effective distance of an immune system can be obtained after T-cell detects the concentration of the molecules 2 with respect to time.Different schemes of S/W ARQ protocols have implemented in Molecular communication(MC)but it requires retransmission of duplicate copies due to the lack of addressing an effective distance.Thus,the simulations are performed in MATLAB and the results obtain higher capture probability and also successful complete transmission of the desired molecules.

关键词： T-cell B-cell MC antigens antibodies diffusion coefficient(D) round trip time(RTT)

A Two-Step Authentication Framework in Mobile Ad-Hoc Networks

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China communications 2007年第1期4卷 28-39页

作者： Nikos Komninos Dimitris Vergados Christos Douligeris Algorithms & Security Group Athens Information Technology19002 Peania Greece dept.of Information and communication Systems engineering University of the Aegean83200 Samos Greece dept.of Informatics University of Piraeus18534 Piraeus Greece

The lack of fixed infrastructure in ad hoc networks causes nodes to rely more heavily on peer nodes for communication.Nevertheless,establishing trust in such a distributed environment is very difficult, since it is not straightforward for a node to determine if its peer nodes can be trusted.An additional concern in such an environment is with whether a peer node is merely relaying a message or if it is the originator of the message.In this paper,we propose an authentication approach for protecting nodes in mobile ad hoc networks.The security requirements for protecting data link and network layers are identified and the design criteria for creating secure ad hoc networks using several authentication protocols are analyzed.Protocols based on zero knowledge and challenge response techniques are presented and their performance is evaluated through analysis and simulation.

关键词： authentication steps link and network layers ad hoc networks

Performance of Multicast communication on Hypercubes

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Journal of Computer Science & Technology 1993年第4期8卷 374-378页

作者：徐海水李显济 Richard W.Nau dept.of Automation Guangdong Institute of MachineryGuangzhou 510643 dept.of Computer engineering Guangdong Institute of TechnologyGuangzhou 510090 dept.of Math/CS Carleton CollegeNorthfieldMN 55057U.S.A.

Based upon hypercube multiprocessor systems,this paper analyses in detail the communication performance under the background of the greedy multicast algorithm GMA.The mean delay time of a mes- sage both at a node and in the system under multicasting is derived.For the sake of contrast,the delay of multicast message is compared with that of multiple one-to-one messages.

关键词： Hypercubes message passing multicasting

Elemental Analysis of Tea Leaves (Camellia Sinensis) and Their Own Soils at Eastern Black Sea Region in Turkey

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光谱学与光谱分析 2020年第4期40卷 1315-1320页

作者： Canan Aksoy Hatice Kabaoglu G khan Apayd n Aziz Safi Engin T rasoglu dept.of Electronics and communication engineering Karadeniz Technical UniversityOfTrabzonTurkey dept.of Computer engineering Gazi UniversityAnkaraTurkey Department of Physics Karadeniz Technical University61080 TrabzonTurkey

People consume tea brewed from the leaves of the Camellia sinensis plant for about 50 centuries. Health benefits of the tea have been investigated for about three decades. Especially green tea shows antitoxic and lots of properties with its determined ingredients. Turkey is not only the one of the best consumer and but also good producer of the tea as being 5 th producer all over the world. It grows eastern region of the Turkey and high quality tea is imported and exported. To have quality tea, grooving soils are also crucial. In the current research, Tea leaves and their own grown soils were collected from 20 stations where the most tea producer cities as Trabzon, Rize and Artvin tea fields of the eastern of Black Sea Region in Turkey. The cultivated tea and their own grown soil samples were analysed by using EDXRF Spectrometry. In the soil samples, the elements Mg, Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba, Pb on percent level and the elements Mg, Al, Si, P, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn and Sr in the tea leaves were detected by using SKRAY 3600-EDXRF.and also the obtained data were evaluated with the Kriging interpolation of geostatistical method. Element content were investigated in the soil and tea samples according to the geological situations and also the relation of elemental difference between the tea and the own grown soil. Pb/Zn ratio was also anaysed in the samples.

关键词： Eastern of Black Sea EDXRF Tea leaves Soils