New Preamble Sequence for WiMAX System with Improved Synchronization Accuracy

Worldwide Interoperability for Microwave Access(WiMAX)trusts Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing(MIMO-OFDM)combination for the deployment of physical layer functions and for connecting the medium access control to the wireless media.Even though Orthogonal Frequency Division Multiplexing(OFDM)facilitates reliable digital broadband transmission in the fading wireless channels,the presence of synchro-nization errors in the form of Carrier Frequency Offset(CFO)and Time Offset(TO)adversely affect the performance of OFDM based physical layers.The objective of this work is to improve the accuracy of the frequency and the time offset estimation in the WiMAX physical layer.A method to enhance the synchro-nization accuracy byfine-tuning the merit factor of the preamble sequence is sug-gested in this paper.Also,a new preamble with improved synchronization accuracy is proposed for the WiMAX system.The performance of the proposed preamble is evaluated in a Rayleigh fading channel and the results of simulations show that the Mean Square Error(MSE)in offset estimation is significantly reduced and it outperforms the standard WiMAX preamble.

Highly Accurate Golden Section Search Algorithms and Fictitious Time Integration Method for Solving Nonlinear Eigenvalue Problems

This study sets up two new merit functions,which are minimized for the detection of real eigenvalue and complex eigenvalue to address nonlinear eigenvalue problems.For each eigen-parameter the vector variable is solved from a nonhomogeneous linear system obtained by reducing the number of eigen-equation one less,where one of the nonzero components of the eigenvector is normalized to the unit and moves the column containing that component to the right-hand side as a nonzero input vector.1D and 2D golden section search algorithms are employed to minimize the merit functions to locate real and complex eigenvalues.Simultaneously,the real and complex eigenvectors can be computed very accurately.A simpler approach to the nonlinear eigenvalue problems is proposed,which implements a normalization condition for the uniqueness of the eigenvector into the eigenequation directly.The real eigenvalues can be computed by the fictitious time integration method(FTIM),which saves computational costs compared to the one-dimensional golden section search algorithm(1D GSSA).The simpler method is also combined with the Newton iterationmethod,which is convergent very fast.All the proposed methods are easily programmed to compute the eigenvalue and eigenvector with high accuracy and efficiency.

Investigating the Potential of Quasi-One-Dimensional Organic Crystals of TTT(TCNQ)2 for Thermoelectric Applications

The purpose of this paper is to present the results of investigations on quasi-one-dimensional organic crystals of tetrathiotetracene-tetracyanoquinodi- methane (TTT(TCNQ)2) from the prospective of thermoelectric applications. The calculations were performed after analytical expressions, obtained in the frame of a physical model, more detailed than the model presented earlier by authors. The main Hamiltonian of the model includes the electronic and phonon part, electron-phonon interactions and the impurity scattering term. In order to estimate the electric charge transport between the molecular chains, the physical model was upgraded to the so-called three-dimen- sional (3D) physical model. Numeric computations were performed to determine the electrical conductivity, Seebeck coefficient, thermal conductivity, thermoelectric power factor and thermoelectric figure-of-merit as a function on charge carrier concentrations, temperatures and impurity concentrations. A detailed analysis of charge-lattice interaction, consisting of the exploration of the Peierls structural transition in TCNQ molecular chains of TTT(TCNQ)2 was performed. As result, the critical transition temperature was determined. The dispersion of renormalized phonons was examined in detail.

A high figure of merit localized surface plasmon sensor based on a gold nanograting on the top of a gold planar film

We investigate the sensitivity and figure of merit （FOM） of a localized surface plasmon （LSP） sensor with gold nanograting on the top of planar metallic film. The sensitivity of the localized surface plasmon sensor is 317 nm/RIU, and the FOM is predicted to be above 8, which is very high for a localized surface plasmon sensor. By employing the rigorous coupled-wave analysis （RCWA） method, we analyze the distribution of the magnetic field and find that the sensing property of our proposed system is attributed to the interactions between the localized surface plasmon around the gold nanostrips and the surface plasmon polarition on the surface of the gold planar metallic film. These findings are important for developing high FOM localized surface plasmon sensors.

Figure of Merit Analysis of a Hybrid Solar-geothermal Power Plant

Figure of merit analysis is a general methodology used to evaluate whether a hybrid power plant could produce more power than two stand-alone power plants. In this paper, the assessment methodology using figure of merit analysis was re-examined for a hybrid solar-geothermal power plant. A new definition of the figure of merit was introduced specifically for a solar boosted geothermal plant to include both the technical and economic factors. The new definition was then applied in a case study of a hypothetical demonstration hybrid solar-geothermal power plant in Australia. The power plant was considered to have a typical net power output of 2.2 MW with a solar energy fraction of 27%. The analysis was performed to compare the power output and capital cost of the hybrid plant with the state-of-the-art (SoA) and existing stand-alone solar and geothermal plants. Based on the new definition, the hybrid plant was found to generally outperform the two existing stand-alone plants. Moreover, at an ambient temperature of 5 °C, the hybrid plant was found to outperform the SoA stand-alone plants when the geothermal temperature was greater than 150 °C. For geothermal temperature of 180 °C on the other hand, the hybrid plant outperformed the SoA stand-alone plants at ambient temperatures lower than 33 °C.

Interpreting the Merits In Aristotle's Poetics

Aristotle's Poetics represents the first major work of literature criticism. In this masterpiece,Aristotle expresses his literary and aesthetical theories. By introducing the merits in Aristotle's Poetics,this thesis tends to reveal Aristotle's large and enduring influence on modern literary criticism.

Properties of a family of merit functions and a merit function method for the NCP

A family of merit functions are proposed, which are the generalization of several existing merit functions. A number of favorable properties of the proposed merit functions are established. By using these properties, a merit function method for solving nonlinear complementarity problem is investigated, and the global convergence of the proposed algorithm is proved under some standard assumptions. Some preliminary numerical results are given.

Merit functions for nonsmooth complementarity problems and related descent algorithm

Under some assumptions, the solution set of a nonlinear complementarity problem coincides with the set of local minima of the corresponding minimization problem. This paper uses a family of new merit functions to deal with nonlinear complementarity problem where the underlying function is assumed to be a continuous but not necessarily locally Lipschitzian map and gives a descent algorithm for solving the nonsmooth continuous complementarity problems. In addition, the global convergence of the derivative free descent algorithm is also proved.

High Thermoelectric Figure of Merit of Ag8SnS6 Component Prepared by Electrodeposition Technique

A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.

Merits and Demerits of Food Additives

Food additive is a double-edged sword. It has merits and demerits. Food additives have such merits as improving sensory properties of foods,preventing deterioration and extending the shelf life,increasing varieties of foods,enhancing convenience of foods,facilitating food processing,and satisfying other demands. However,excessive and illegal use of food additives will exert adverse influence on food security.Therefore,it is required to take proper measures to bring merits of food additives into full play,and get rid of their demerits.

Running slow or running fast;that is the question:The merits of high-intensity interval training

In a recent issue of the Journal of Sport and Health Science,García-Pinillos et al.~1 reviewed evidence on the effects of highintensity intermittent training(interval training)(HIIT)on muscular and performance adaptations in recreational runners.

Task-based Language Teaching： Merits and Issues

With growing tendency and widespread application, TBLT has attracted considerable attention from educator teachers,theorists and researchers. The paper commences by offering some influential definitions of‘task', varying classifications of differ-ent types of task, and criteria for judging a task. Then, compared with teaching approaches before the emergence of CLT, TBLT isnew and has many distinct merits. Meanwhile, since it is a newly-established approach, some problems and difficulties in comple-menting TBLT are inevitable. A number of genuine issues raised in Asian language teaching classrooms are examined.

石墨烯纳米流体在PV/T系统中的分频性能分析

文章对质量浓度分别为0.02‰,0.05‰,0.1‰的水基石墨烯纳米流体的分频特性进行了研究。采用双光程法测试了光谱透过率,可理论分析石墨烯纳米流体的分频性能。在90 min模拟光照的条件下,分析不同浓度石墨烯纳米流体和水作为分频液时分频型PV/T系统集热效率、电效率和综合效率的变化情况。结果表明:0.02‰石墨烯纳米流体的光谱透过率最高,在400~900 nm的单晶硅电池较佳响应波段,其透过率为66.8%;将取热温度设定为40℃,0.1‰纳米流体达到40℃时,热效率最高达39.7%;水作为PV/T系统分频液时,PV电池输出效率最高为10.9%;同时,利用性能评价函数MF(The Merit Function)来评估分频液对PV/T系统综合性能的影响,当达到取热温度40℃时,0.1‰石墨烯分频液瞬时MF值最高达1.85。

Design of multilayer cellular neural network based on memristor crossbar and its application to edge detection

Memristor with memory properties can be applied to connection points(synapses)between cells in a cellular neural network(CNN).This paper highlights memristor crossbar-based multilayer CNN(MCM-CNN)and its application to edge detection.An MCM-CNN is designed by adopting a memristor crossbar composed of a pair of memristors.MCM-CNN based on the memristor crossbar with changeable weight is suitable for edge detection of a binary image and a color image considering its characteristics of programmablization and compactation.Figure of merit(FOM)is introduced to evaluate the proposed structure and several traditional edge detection operators for edge detection results.Experiment results show that the FOM of MCM-CNN is three times more than that of the traditional edge detection operators.

乡村治理积分制的“银行”模式研究:运行机制、突破切口与秩序重构

近年来乡村治理的积分制探索向纵深推进,其中以计量手段嵌入治理过程的“银行”模式独具特色,有效重建了乡村治理的运行机制与参与格局。论文从案例研究入手,分析了基于普惠金融的“道德银行”、整治人居环境的“绿色银行”、锚定互助养老的“时间银行”三种模式,通过比较运营策略,归纳内在机理,提出积分制重构乡村治理的四个切口:利益驱动、市场主体、数字技术与乡土文化。积分制能否在农村基层治理变革中重构村庄秩序,需要妥善解决两大问题:资源能否持续、约束是否有力。以零存整取、资产增值为特征的“银行”模式,一方面通过“数目字管理”机制拓展了德行激励形式,另一方面通过乡土授信建构“连带责任”机制,对村民及其家庭形成强约束,从而破解“公共性困境”,或将成为一条有效的乡村治理探索路径。

风险政治学视域下中国特色选贤任能委任制的制度风险防范及发展前景

制度风险是风险政治学视域下极为重要的研究领域。制度既是人类对风险的理性自觉应对,也是重要的风险源。制度风险关涉制度本身和制度环境两个方面,既指制度自身缺陷导致出现违背制度目标、功能、价值等现象的风险,也包括制度环境对实现制度目标、功能、价值的干扰。作为具有中国特色社会主义制度属性的干部制度形式,选贤任能委任制有吸纳选拔干部和培养塑造干部、统筹配置干部资源、巩固执政党执政地位和维护执政党权威、践行社会主义民主政治等制度优势,也潜藏目标偏离、功能弱化、价值戕害、“劣币”效应等制度风险。本文将制度目标、制度功能、制度价值、制度环境四个因素作为制度风险的考察因素,分析它们对制度风险生成的影响和作用,厘清选贤任能委任制的制度优势和潜在风险,并在政治结构和制度环境中深入探讨制度发展与改革前景,为坚持和完善选贤任能制度,促进马克思主义政党建设以及推进国家治理体系和治理能力现代化提供借鉴参考。

The effect of pH on stability and thermal performance of graphene oxide and copper oxide hybrid nanofluids for heat transfer applications:Application of novel machine learning technique

This paper investigates the effects of pH on stability and thermal properties of copper oxide(CuO),graphene oxide(GO),and their hybrid nanofluid(HNF)at different mixing ratios.Initially,sol-gel and Hummer’s method was employed for the synthesis of CuO and GO nanoparticles(NPs),and they are characterized with various techniques.The effects of two different surfactants were analyzed on nanofluid’s(NF’s)stability at different pH values.The properties like thermal conductivity(TC)and viscosity(VST)of NFs were measured at different volume concentration(0.1 vol%to 1.0 vol%)and temperature range of 30-60℃,respectively.The TC and VST of GO/CuO(50:50)HNF are higher than that of GO/CuO(20:80).The figure of merit(FOM)is determined for the studied HNFs.The correlations were presented to calculate the TC as well as VST of HNFs.Two modern novel machine learning-based ensemble approaches were employed for predictive model development for TC and VST of considered HNFs.The comparison of prognostic models with Taylor’s diagram revealed that Bayesian optimized support vector machine(BoASVM)was superior to Bayesian optimized boosted regression trees(BoA-BRT)for both TC and VST models.

Thermoelectric signature of Majorana zero modes in a T-typed double-quantum-dot structure

The thermoelectric effect of the system is theoretically investigated,by coupling Majorana zero mode to the T-typed double-quantum-dot-structure in different ways.It is found that when a single Majorana zero mode is coupled to one of the quantum dots(QDs),the thermoelectric efficiency is suppressed due to the leakage of Majorana zero modes into the QDs.When the Majorana zero mode is coupled to QD2,the suppression of the thermoelectric efficiency is more serious than that of QD1.Furthermore,when two Majorana zero modes are introduced simultaneously,suppression of the thermoelectric effect still takes place.We believe that such results can be candidates for the detection of Majorana bound states and help us understand the role of Majorana zero mode in thermoelectricity.

Thermoelectric generators and their applications:Progress,challenges,and future prospects

Our community currently deals with issues such as rising electricity costs,pollution,and global warming.Scientists work to improve energy harvesting-based power generators in order to reduce their impacts.The Seebeck effect has been used to illustrate the capacity of thermoelectric generators(TEGs)to directly convert thermal energy to electrical energy.They are also ecologically beneficial since they do not include chemical products,function quietly because they lack mechanical structures and/or moving components,and may be built using different fabrication technologies such as three-dimentional(3D)printing,silicon technology,and screen printing,etc.TEGs are also position-independent and have a long operational lifetime.TEGs can be integrated into bulk and flexible devices.This review gives further investigation of TEGs,beginning with a full discussion of their operating principle,kinds,materials utilized,figure of merit,and improvement approaches,which include various thermoelectric material arrangements and utilised technologies.This paper also discusses the use of TEGs in a variety of disciplines such as automobile and biomedical.

SiC trench MOSFET with dual shield gate and optimized JFET layer for improved dynamic performance and safe operating area capability

A novel silicon carbide(SiC) trench metal–oxide–semiconductor field-effect transistor(MOSFET) with a dual shield gate(DSG) and optimized junction field-effect transistor(JFET) layer(ODSG-TMOS) is proposed. The combination of the DSG and optimized JFET layer not only significantly improves the device’s dynamic performance but also greatly enhances the safe operating area(SOA). Numerical analysis is carried out with Silvaco TCAD to study the performance of the proposed structure. Simulation results show that comparing with the conventional asymmetric trench MOSFET(Con-ATMOS), the specific on-resistance(Ron,sp) is significantly reduced at almost the same avalanche breakdown voltage(BVav). Moreover, the DSG structure brings about much smaller reverse transfer capacitance(Crss) and input capacitance(Ciss), which helps to reduce the gate–drain charge(Qgd) and gate charge(Qg). Therefore, the high frequency figure of merit(HFFOM) of Ron,sp·Qgdand Ron,sp· Qgfor the proposed ODSG-TMOS are improved by 83.5% and 76.4%, respectively.The switching power loss of the proposed ODSG-TMOS is 77.0% lower than that of the Con-ATMOS. In addition, the SOA of the proposed device is also enhanced. The saturation drain current(Id,sat) at a gate voltage(Vgs) of 15 V for the ODSGTMOS is reduced by 17.2% owing to the JFET effect provided by the lower shield gate(SG) at a large drain voltage. With the reduced Id,sat, the short-circuit withstand time is improved by 87.5% compared with the Con-ATMOS. The large-current turn-off capability is also improved, which is important for the widely used inductive load applications.