一维渐变介电张量液晶光波导的模解器

液晶光波导本征模场分析的准确度直接影响到其器件的性能。采用了以下步骤去准确求解电介质张量沿着一个维度渐变的液晶光波导中的模场分布。考虑液晶场致重新取向的渐变特性,对液晶的各向异性磁场耦合方程组进行了有限差分离散,然后改进传统差分算符矩阵得到了能准确求解液晶光波导中模式的特征值方程。最后,给出一个数值案例,将求解结果与本征模内场分量间的耦合关系比较从而验证了该模解器的有效性。

A Novel Analytical Model for Surface Electrical Field Distribution and Optimization of TFSOI RESURF Devices

A novel analytical model for the thin film silicon on insulator (TFSOI) reduced surface field (RESURF) devices has been proposed.Based on the 2-D Poisson equation solution,the analytical expressions for the surface potential and field distributions are derived.From this analysis,the optimum design condition for the maximum breakdown voltage is obtained.The dependence of the maximum breakdown voltage on the drift region length is examined and the relationship between the critical doping concentration and the front- and back- interface oxide layer thickness is discussed.The numerical simulation performed by the advanced semiconductor simulation tool,DESSIS-ISE,has been shown to support the analytical results.

Numerical simulation of fluid dynamics in rare earth chloride solution in jet-flow pyrolysis reactor

Rare earth oxide was prepared via direct pyrolysis of rare earth chloride solution. Based on this technique, a new-type jet-flow pyrolysis reactor was designed, and then the fluid dynamics (pressure and velocity) inside the reactor was numerically simulated using a computational fluid dynamics method. The self-produced pressure (p) and the fuel inlet velocity (v) satisfied a quadratic function,p=0.06v2+0.23v?4.49. To fully utilize the combustion-generated heat in pyrolysis of rare earth chloride, an appropriate external pressure p=v2+3v?4.27 should be imposed at the feed inlet. The 1.25- and 1.5-fold increase of feed inlet diameter resulted in decline of adsorption dynamic pressure, but the intake of rare earth chloride increased by more than 30% and 60%, respectively. The fluid flow in the reactor was affected by the feeding rate; the fluid flow peaked near the throat of venturi and gradually smoothed down at the jet-flow reactor’s terminal along with the sharp decline of feeding rate.

Flume simulation of wave-induced release of internal dissolved nitrogen in Taihu Lake,China

A wave flume simulator was used to study internal nitrogen release from the surface sediment collected from Taihu Lake, China. Particulate nitrogen concentrations were positively correlated with the concentrations of suspended solids, primarily from surface erosion related to the shear stress and duration of wave action. In response to 4 cm- and 10 cm-high wave production representing waves generated in Taihu Lake by gentle and gusty winds, respectively, the mean dynamic release rate of ammonium （NH4＋） from the sediment to the overlying water was 1 × 10-3 mg/（m2.s） and the NH4＋ concentration in the overlying water increased by 0.016 mg/L, indicating that waves resulting from strong wind can induce the rapid release of dissolved nitrogen from Taihu Lake sediments. The decrease in interstitial NH4＋ concentrations at all sediment depths was associated with an increase in NH4＋ concentrations in the overlying water by 0.01 mg/L, showing that sediment below the eroded layer was the main source of internal nitrogen release. Changes in the interstitial dissolved oxygen and NH4＋ concentrations showed that wave-induced pore water movement can greatly increase the diffusion rate, and that these 15 cm. Diffusion induced by pore water movement sediment layer in Taihu Lake. effects can influence the sediment to a depth of at least may be very important for the formation of an active

Refinement of an Analytical Approximation of the Surface Potential in MOSFETs

A refinement of an analytical approximation of the surface potential in MOSFETs is proposed by introducing a high-order term. As compared to the conventional treatment with accuracy between 1nV and 0. 03mV in the cases with an oxide thickness tox = 1 ～ 10nm and substrate doping concentration Na = 1015 ～ 1018 cm-3 , this method yields an accuracy within about 1pV in all cases. This is comparable to numerical simulations, but does not require trading off much computation efficiency. More importantly, the spikes in the error curve associated with the traditional treatment are eliminated.

Simulation logging experiment and interpretation model of array production logging measurements in a horizontal well

The distributions of local velocity and local phase holdup along the radial direction of pipes are complicated because of gravity differentiation,and the distribution of fluid velocity fi eld changes along the gravity direction in horizontal wells.Therefore,measuring the mixture flow and water holdup is difficult,resulting in poor interpretation accuracy of the production logging output profile.In this paper,oil–water two-phase flow dynamic simulation logging experiments in horizontal oil–water two-phase fl ow simulation wells were conducted using the Multiple Array Production Suite,which comprises a capacitance array tool(CAT)and a spinner array tool(SAT),and then the response characteristics of SAT and CAT in diff erent fl ow rates and water cut production conditions were studied.According to the response characteristics of CAT in diff erent water holdup ranges,interpolation imaging along the wellbore section determines the water holdup distribution,and then,the oil–water two-phase velocity fi eld in the fl ow section was reconstructed on the basis of the fl ow section water holdup distribution and the logging value of SAT and combined with the rheological equation of viscous fl uid,and the calculation method of the oil–water partial phase fl ow rate in the fl ow section was proposed.This new approach was applied in the experiment data calculations,and the results are basically consistent with the experimental data.The total fl ow rate and water holdup from the calculation are in agreement with the set values in the experiment,suggesting that the method has high accuracy.

Simulation of hydrocarbons pyrolysis in a fast-mixing reactor

Currently, thermal decomposition of hydrocarbons for the production of basic petrochemicals(ethylene, propylene) is carried out in steam-cracking processes. Aside from the conventional method, under consideration are alternative ways purposed for process intensification. In the context of these activities, the method of hightemperature pyrolysis of hydrocarbons in a heat-carrier flow is studied, which differs from previous ones and is based on the ability of an ultra-short time of feedstock/heat-carrier mixing. This enables to study the pyrolysis process at high temperature(up to 1500 K) at the reactor inlet. A set of model experiments is conducted on the lab scale facility. Liquefied petroleum gas(LPG) and naphtha are used as a feedstock. The detailed data are obtained on temperature and product distributions within a wide range of the residence time. A theoretical model based on the detailed kinetics of the process is developed, too. The effect of governing parameters on the pyrolysis process is analyzed by the results of the simulation and experiments. In particular, the optimal temperature is detected which corresponds to the maximum ethylene yield. Product yields in our experiments are compared with the similar ones in the conventional pyrolysis method. In both cases(LPG and naphtha), ethylene selectivity in the fast-mixing reactor is substantially higher than in current technology.

Design of a(480,240)CMOS Analog Low-Density Parity-Check Decoder

Digital low-density parity-check(LDPC) decoders can hardly meet the power-limits brought by the new application scenarios. The analog LDPC decoder, which is an application of the analog computation technology, is considered to have the potential to address this issue to some extent. However, due to the lack of automation tools and analog stopping criteria, the analog LDPC decoders suffer from costly handcraft design and additional decoding delay, and are not feasible to practical applications. To address these issues, a decoder architecture using reusable building blocks is designed to lower the handcraft design, and a probability stopping criterion that is specially designed for analog decoder is further planned and implemented to reduce the decoding delay. Then, a(480,240) CMOS analog LDPC decoder is designed and fabricated in a 0.35-μm CMOS technology. Experimental results show that the decoder prototype can achieve 50 Mbps throughput when the power consumption is about 86.3m W, and the decoding delay can be reduced by at most 93% compared with using the preset maximum decoding delay in existing works.

Joint detection method of pornographic images with skin-like color background

A novel approach is proposed to automatically detect pomographic images with skin-like color background on the Intemet using the locations of human faces and bodies. It has two separate skin-color detection steps： the first one is to quickly detect the potential human skin-color regions; and the second one is to use an off-the-shelf face detector to locate a human face and then apply hypothesis testing based on series of assumptions which take into account the face-height ratio, body orientation and modem photograph composition common sense, etc. After that, a template matching method is used to further discriminate normal images or pornographic ones. Experimental results show that the proposed method has high precision and real time speed.

The Genoese Commune Massari＇s Ledger of 1340： The First Computer Modeling Experience and Its Results

Since 1865, the scholars from different countries have been studying the Genoese Massari＇s ledger of 1340. The authors have used a fundamentally new approach when studying this famous register. The authors have also analyzed the full-scale financial processes （from registering the expenses of the commune to their coverage by revenue） instead of analyzing some separate transactions which could prove the presence of the double-entry when registering each economic fact. This becomes possible as a result of the reconstruction of medieval entries and registers in the form of a modem account and the construction of the computer model of the whole ledger of 1340. The model of the system is formed according to seven summits of the revenue of the commune, which are distributed upon many factors of registered expenses and united into 17 reporting points. The special attention is paid to the date of the transaction. The authors have found many answers to some questions which were mysteries before. The explanation is given to the sales of goods below the purchasing price and to the exchange of money with significant losses.

Multi-loop Constrained Iterative Model Predictive Control Using ARX -PLS Decoupling Structure

A multi-loop constrained model predictive control scheme based on autoregressive exogenous-partial least squares(ARX-PLS) framework is proposed to tackle the high dimension, coupled and constraints problems in industry processes due to safety limitation, environmental regulations, consumer specifications and physical restriction. ARX-PLS decoupling character enables to turn the multivariable model predictive control(MPC) controller design in original space into the multi-loop single input single output(SISO) MPC controllers design in latent space.An idea of iterative method is applied to decouple the constraints latent variables in PLS framework and recursive least square is introduced to identify ARX-PLS model. This algorithm is applied to a non-square simulation system and a stirred reactor for ethylene polymerizations comparing with adaptive internal model control(IMC) method based on ARX-PLS framework. Its application has shown that this method outperforms adaptive IMC method based on ARX-PLS framework to some extent.

ODE-Solver-Oriented Computational Method for the Structural Dynamic Analysis of Super Tall Buildings

The paper is to introduce a computational methodology that is based on ordinary differential equations （ODE） solver for the structural systems adopted by a super tall building in its preliminary design stage so as to facilitate the designers to adjust the dynamic properties of the adopted structural system. The construction of the study is composed by following aspects. The first aspect is the modelling of a structural system. As a typical example, a mega frame-core-tube structural system adopted by some famous super tall buildings such as Taipei 101 building, Shanghai World financial center, is employed to demonstrate the modelling of a computational model. The second aspect is the establishment of motion equations constituted by a group of ordinary differential equations for the analyses of free vibration and resonant response. The solutions of the motion equations （that constitutes the third aspect） resorted to ODE-solver technique. Finally, some valuable conclusions are summarized.

Life detection and location methods using UWB impulse radar in a coal mine

An ultra-wideband impulse radar was studied for the detection of buried life in coal mines. An improved Empirical Mode Decomposition (EMD) method based on a cross-correlation filter was proposed for reduction of multipath and noise interference. Multipath interference was first removed by cross-corre- lation filtering. Then the delays of each pulse in every echo were summed. An EMD algorithm was used for noise reduction for the total delay of each echo. The corresponding EMD results of every echo were then summed and averaged. Finally, evidence for the existence of buried life and their position were obtained from amplitude-frequency curves of the averaged EMD results. Detailed simulation experi- ments are presented to validate the effectiveness of this proposed method. The experimental results show that this method can efficiently eliminate multipath interference and reduce noise interference in echoes, which makes detection and location of buried life in coal mines more accurate.

A Confirmatory Factor Analysis on the Views and Constructs for Knowledge Management in India

For a modem organization, KM （Knowledge Management） plays a critical role in terms of strategy development. Key determinants of KM lead to better understanding of various influences that enable and organisation to face competitors. For this reason, sharing and managing knowledge in an organization involves a series of activities that are related to the specific functional aspects of that organisation. In order to foster KM in an organisation, these functional aspects must be understood properly, and within the context of a given organisation, its geographical location and the cultural aspects of the given organisation. This was the premise on which this study was conducted with Indian organisations. A mixed method approach was used to understand the views of Indian region towards KM in this study, be selecting 400 participants in four major each cities. A second order regression model was built using Structural Equation Model to arrive at nine constructs that are relevant to KM in an organisation.

Core Competence Evaluation Based on Grey Correlation Degree Airport Enterprise

How to have a more long-term vitality in the fierce competition in the industry and complex market environment, to have the more powerful anti-risk capability and competitive advantage is a modem airport managers have an urgent need to solve the problem. Because the nature of this paper will be ＂core competence＂ deemed to maintain long-term vitality and airport businesses a competitive advantage in the fierce competition in the industry. It can interpret and summarize the definition of core competence connotation airport, specificity and identification method to construct a two-dimensional Airport Enterprise core competence evaluation system and core competencies of three large enterprises of China＇ s civil aviation airport with the area to evaluate the scientific and operational test evaluation model.

The establishment of 3D visualization modeling for the jointed slope

The 3D visualization model of slop with structural plane can displayed the characters of structural plane in slop directly, and illustrated the spatial combination. It is a modem and critical question in the field of geotechnical engineering. Based on the peculiarity of the reconnaissance and the research of the visualization by formers, systemized the method fit for building 3D visualization model of slop with structural plane. Write the special program with Visual C^-＋ computer language and illustrated it by OpenGL, the program can displayed and captured the random section plane. The program has a satisfied result by proving with the real projects.

Hazard Mitigation Planning for Debris flow Based on Numerical Simulation Using Kanako Simulator

Debris flow often causes enormous loss to life and property,especially on alluvial fans.Engineering structures such as retention check dams are essential to reduce the damage.In hazard mitigation evaluation and planning it is of significance to determine the location,size and type of dam and the effects of damage mitigation.We present a numerical simulation method using Kanako simulator for hazard mitigation planning of debris flow disaster in Tanjutani Gully,Kyoto City,Japan.The simulations were carried out for three situations:1) the simulations of erosion,deposition,hydrograph changing and inundation when there were no mitigation measures;2) the simulations of check dams in four locations(470 m,810 m,1,210 m and 1,610 m from the upstream end) to identify the best location;3) the simulations of check dams of three types(closed,slit and grid) to analyze their effects on sediment trapping and discharge reduction.Based on the simulations,it was concluded that two closed check dams(located at 470 m and 1,610 m from the upstream end) in the channel and a drainage channel on the alluvial fan can reduce the risk on the alluvial fan to an acceptable level.

Refurbishment of Significant Timber Structures in Slovakia

The paper presents an analysis and a subsequent refurbishment of significant buildings in Slovakia. The analysis focuses on the load-bearing timber roof-structures. There are three sacral objects and one long-span sporting hall presented. The paper tries to introduce the background of difficult refurbishment process. Before the refurbishment, a thorough process of investigation is required This process includes four basic steps. General information about the load-bearing structure is obtained from the geodetic survey that foregoes the process of diagnostic inspection. The diagnostic survey focuses on the defects of the structure, their degree and possible origin. Modem methods of computer modelling help to understand the structural operation and help to find reserves of carrying capacity. Structural analysis should take into account all detected defects and the joint types, which can influence the transfer of forces. The refurbishment project is usually a brief, but clear summary for fulfilling the needs of Monument Board and building process. All the steps require knowledge from different fields and require professional approach.

A Comprehensive Evaluation Method of Sports Modernization Based on AHP

In order to improve the modernization level of sports comprehensive evaluation, a comprehensive evaluation method of sports modernization based on analytic hierarchy process （AHP） is proposed. An index analysis model for constructing the comprehensive evaluation of sports modernization is constructed, spatial modeling of information feature distribution is taken based on nonlinear time series analysis method for comprehensive evaluation of sports modernization, control objective function of comprehensive evaluation of sports modernization is constructed by analytic hierarchy process, optimal control parameters is obtained and comprehensive evaluation and optimization of sports modernization are realized. The simulation results show that the method is applied in comprehensive evaluation modem sports, it has performance of high reliability and good accuracy.

Supply chain management research directions for future development

With the rapid development of electronic commerce, supply chain management is facing more and more new challenges. Therefore, it is particularly important to study the development of clear direction of supply chain. However, the supply chain is composed of different interest subjects, each subject in order to achieve the maximization of their own interests and adopt different measures, is a complex, huge system, has brought the huge challenge to the supply chain management. In this paper, the research on Supply Chain Management in the current situation, characteristics and the modem supply chain management are summarized, and combined with new challenges of supply chain management to predict future research direction is the development of supply chain management, in order to make the supply chain management to the greatest extent satisfy the consumer e-commerce mode increasingly popular.