bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-Equidistant Numerical Methods for Ordinary Differential Equation with Periodical Boundary Value
Authors: Cai Xin
Published: February 2011

Ordinary differential equation with periodical boundary value and small parameter multiplied in the highest derivative was considered. The solution of the problem has boundary layers, which is thin region in the neighborhood of the boundary of the domain. Firstly, the properties of boundary layer were discussed. The solution was decomposed into the smooth component and the singular component. The derivatives of the smooth component and the singular component were estimated. Secondly, mesh partition techniques were presented according to one transition point method and multi-transition points method. Thirdly numerical methods based on non-equidistant mesh partition were presented to solve the problem. Finally error estimations were given for both computational methods.
Displacement Analysis of the 3SPS-3CCS Mechanism Based on Hyper-Chaotic Newton-Downhill Method
Authors: Luo You Xin , Che Xiao Yi , Zeng Bin
Published: February 2011

The forward displacement analysis of parallel mechanism is attributed to find the solutions of complicated nonlinear equations and it is a very difficult process. Taking chaotic sequences as the initial values of Newton-downhill method, we can find all the solutions of equations quickly. Making use of existing chaos system and discovering new chaos system to generate chaotic sequences with good properties is the key to the Newton-downhill method based on Chaos sequences. Based on utilizing hyper-chaotic Hénon mapping to obtain initial points, a new method of finding all real number solutions of the nonlinear questions is proposed. Using cosine matrix method, the author established the mathematical model of forward displacement for the generalized 3SPS-3CCS parallel robot mechanism and a numerical example is given. Compared to the quaternion method building mathematical model, the result shows cosine matrix method building mathematical model and hyper-chaotic Newton-downhill method finding solution is brief and high calculation efficiency as the calculation is done in real number range. The proposed method has universality which can be used in forward displacement of other parallel mechanism.
NDA Based Hierarchical Classification Scheme for Identifying the Contributors to a Multivariate Control Chart
Authors: Huang H.Y. , Chien Jong Chih
Published: February 2011

Many multivariate control charts have been proposed for monitoring several related quality characteristics simultaneously. However, even when an out-of-control signal is detected, the employed multivariate control charts generally do not provide any interpretable information associated with that signal. That is, the contributors of the out-of-control event can not be identified by the charts. Hence, how to tackle this interpretation problem effectively is an important issue in multivariate process control. One rarely addressed but very crucial property of this interpretation problem is that the number of possible outcomes can be very large. According to this key property, a nonparametric discriminant analysis (NDA)-based hierarchical classification scheme is proposed in this paper. A simulation experiment including several popular classification methods was conducted for evaluating the performance of the proposed method. The result shows that our proposed scheme is very competitive when measured against these popular methods.
Fuzzy PID Control for Intelligent Smartcar System with CCD Camera
Authors: Qu Shao Cheng , Tian Yao , Chen Chan
Published: February 2011

This paper introduces a design of intelligent smartcar system based on MCU SPCE061A and MCU 89S52. The practical path images are obtained using by the CCD camera, then a double P control method is applied to dynamically adjust steering angle. Based on fuzzy relationship between angle and velocity, the PD controller is proposed to achieve path identification and arbitrary track. Experiments show that the response and stability of the proposed system are excellent.
A Research on the Construction Material Export and Energy Consumptions Using the Gravity Model
Authors: Song Yu , Wei Long , Liu Chun Lu
Published: February 2011

This paper applies a gravity model to estimate the relationships between energy consumptions and many kinds of construction material export over the period 1992-2009 in China. The empirical result shows that energy consumptions have a significant and positive influence on the construction material export of China.
Realization of Interactive Communication among Multi-Sensors Based on CAN Bus
Authors: Yan Shi Hua , Li Gang
Published: February 2011

Aiming at the problems of the interactive communication among infrared multi-sensors under the electromagnetic interference, an interactive network is developed based on CAN bus controller which is embed in TMS320F2812 DSP. After the hardware design of the network system is introduced, a application layer protocol of CAN bus network for simple and effective communications is proposed. Following the protocol, software program is designed, and the transmission efficiency is improved obviously. Finally, the relationship between nodes and baud Rate is shown after analyzing the transmission time delay.
Dynamic Disturbance Simulation of Modal Control and Control Model of Torsional Vibration of the Rolling Mill
Authors: Zhao Wu , Huang Dan
Published: February 2011

For suppressing torsional vibration on main driving system of the rolling mill, the paper studied modal control and control model of torsional vibration. Dynamic disturbance of the rolling mill main driving system were induced by small perturbation from torque fluctuation. Modal control analysis were investigated on include amplitude and phase response on reference change or load change, bode diagrams, and time domain simulations. Torque fluctuation reflects non-steady cyclical or quasi-cyclical characteristics on the torsional vibration system. Control model had been reconstructed from inversion of dynamic topology theory. The result of simulation showed that the established control model for suppressing torsional vibration was effectiveness. Feedback control experiment of nipping and throwing steel on the rolling mill’s main driving system using reaction control tactic was proved it could be easy input and output for controling to suppressing vibration.
A Deterministic Method for a Class of Fractional Programming Problems with Coefficients
Authors: Yin Jing Ben , Li Kun
Published: February 2011

The sum of linear fractional functions problem has attracted the interest of researchers and practitioners for a number of years. Since these types of optimization problems are non-convex, various specialized algorithms have been proposed for globally solving these problems. However, these algorithms are only for the case that sum of linear ratios problem without coefficients, and may be difficult to be solved. In this paper, a deterministic algorithm is proposed for globally solving the sum of linear fractional functions problem with coefficients. By utilizing an equivalent problem and linear relaxation technique, the initial non-convex programming problem is reduced to a sequence of linear relaxation programming problems. The proposed algorithm is convergent to the global optimal solution by means of the subsequent solutions of a series of linear programming problems.
VOC Emission from a Multi-Layer Work Surface (Panel) of a Workstation System
Authors: Wang Fang , Ye Chao , Wang Jing Yi , Wang Yu Teng , Gao Song Tao
Published: February 2011

Volatile organic compounds (VOCs) are main type of indoor pollutants which are found in many workstation materials. In multi-layer work surface panels, different VOCs have different chemical and physical properties which will affect their transport properties and storage properties. Therefore, the VOC emission process and emission rate are generally different and depend on the type of VOCs. The effect of the initial condition, such as temperature, relative humidity, air change rate, initial VOC concentration and pollutant type are evaluated separately. This paper uses a build environment simulation (BES) program to investigate the effect of these factors on the VOC concentration in the air. Based on the theoretic analysis, several means can be adopted to reduce the pollutant emission and improve the indoor air quality (IAQ).
Biquadratic TC-Bézier Curves with Shape Parameter
Authors: Liu Xu Min , Yang Xian Peng , Wu Yan Ling
Published: February 2011

Shape controlling is a popular topic in curves and surfaces design with free form. In this paper, a new curve, to be called Biquadratic TC-Bézier curves with shape parameter , is constructed in the space . We show that such curves share the same properties as the traditional Bézier curves in polynomial spaces. The shape of new curves, representing circle and ellipse accurately, can be adjusted by changing the value of the parameter . Then we give the G1 continuity conditions of Biquadratic TC-Bézier curves with shape parameter and its application in surfaces modeling.
Mechanism of High Modulus and Strength of Unio Douglasiae Shell
Authors: Chen Bin , Luo Ji , Yuan Quan , Fan Jing Hong
Published: February 2011

Scanning electron microscope (SEM) observation shows that the shell of a Unio douglasiae is a kind of bioceramic composite consisting of laminated aragonite and organic materials. The aragonite layers further consist of thin and long aragonite fibers. The aragonite fibers possess high density in the shell and their diameter is within nanometer scale. The mechanism of the high modulus and high strength of the shell were investigated based on the observed nanometer structure of the aragonite fibers and the rule of mixtures Young’s modulus as well as the Griffith criterion. It reveals that the high density and the nanometer scale of the aragonite fibers endow the shell with high modulus and fracture strength.
Properties Analysis of Bolted Composite T-Joint
Authors: Wang Zhen Qing , Zhou Song , Zhou Jian Sheng , Sun Xiao Yu
Published: February 2011

Composite materials not only have good mechanical performances but also have excellent durability and ability to be formed into complex shape. So advanced composite materials are used extensively in ship industry. In the composite ship structure the T-joint is one of the common joint in practice. As the main load-bearing structure of ship, the mechanical and reliability designs of T-joint are the important aspects of the ship structure design. The traditional composite T-joint is bonded joint, and adhesive strength has obvious influence on the properties of T-joint. To improve the properties of composite T-joint, in this paper the bolted composite T-joint is chosen for studying. Finite element method is used to investigate the properties of bolted T-joint. The influences of bolt-clamping load and friction coefficient on the stress distribution of bolt-hole edge are investigated. Some conclusions can be used as references for the design of bolted composite T-joint.
A Research on the Trinity Mechanism of Atomization Based on Centrifugation Oscillation and Impact Breakage
Authors: Luo Feng , Qiu Ke
Published: February 2011

The paper advances a new atomization mechanism combining the centrifugal, the oscillating and the impact breakage atomization as a trinity, breaking through the traditionally single atomization model. The atomization mechanism raised here makes full use of the comprehensive effects of the centrifugal atomization, the oscillating atomization and the impact breakage atomization, synthesizing the superiorities of the three as an organic and powerfully efficient whole, and making their mutual reactions stronger step by step. Among the three, the impact breakage atomization is a new auxiliary mechanism, which can considerably improve the droplet’s atomizing process after the centrifugal and the oscillating atomization, producing much better an atomizing result. It is very convenient, simple and direct to fulfill “the-three-in-one”. This atomization mechanism not only can achieve the goal of even atomization and much tinier droplets, but can be energy-efficient with low cost and less labor intensity as well. Therefore it is a highly practical and useful method.
Design of Cotton-Picking Laptop Machine without Winding
Authors: Luo Feng , Qiu Ke
Published: February 2011

The cotton fiber winding has always been a problem for a picking cotton machine to conquer. This design theoretically pointed out the reasons, at the same time around launched a mechanical cotton-pickers laptop without transmission mechanism, but with a flexible helicopter. This machine is made of cotton picking a direct drive of micro-motors to rotate, the protection cover to picking cotton, and gear transmission by the wind, thus instantly complete cotton flower of picking cotton, improve efficiency, but also greatly reduce the labor intensity of cotton.
DEA-Based Measurement of Information System Performance
Authors: Wang Hong Wei , Liu Yu , Zhou Man , He Shao Yi
Published: February 2011

This paper selects YMK-DEA and C2GS2-ISS models for the evaluation of performance of complex information systems. Referring the balanced scorecard, evaluation indexes for IS performance are presented from four perspectives, including finance, customer, internal processes and learning and growth. Taking the information systems from 30 steel sale enterprises as examples, this paper uses YMK-DEA and C2GS2-ISS models to evaluate IS performance from the angles of both technical efficiency and scale efficiency, and compares the results with those from C2R and C2GS2 models. Finally, some suggestions for IS improvement are given.
A New Solution Method for Large-Scale System Optimization Operation
Authors: Wang Zhi Guo
Published: February 2011

Aiming at shortcomings in global searching capacity and diversity of Pareto set existing in the traditional MOPSO and in order to enhance the diversity of pareto solutions, quasi-pareto solutions are constructed by sub-ant-colony algorithm which adopts its own and other sub-ant-colony heuristic information and quasi-pareto solutions obtained by every ant are used for control judegement. A crowding distance sorting based multi-objective particle swarm optimization algorithm is proposed. The constructed farther-group ants with the quasi-pareto solutions which act as space nodes constitute traveling salesman problem, hence, leading to the enhancement of the uniform distribution of pareto solutions. With the elitism strategy, the evolution of the external population is achieved based on individuals’ crowding distance sorting by descending order, to delete the redundant individuals in the crowding area. The update of the global optimum is performed by selecting an individual with a relatively bigger crowding distance, to lead the particles to evolve to the disperse region. Effectiveness of the algorithm with two and three objectives is proved by the optimization of three standard test problems. Comparison results illustrate that it outperformed NSGA-II and SPEA2 in the convergence and diversity characteristics of pareto optimal front.
Design of Transmission Endurance Tester with Electric Energy Recycle Technology
Authors: Li Xi Qin , Song De Yu , Liu Bing
Published: February 2011

Endurance test of vehicle transmission usually takes long time and spends a lot of electric energy. In order to save energy, a new kind of transmission endurance tester equipped with a DC brake motor and a digital DC reversible speed governor is developed. The tester can transfer electricity generated by the brake motor back into the electric grid. The experiment result shows that the average ratio of electricity recycle is as high as 68 percent. The tester can be used for transmission endurance test of various kinds of construction machineries and vehicles.
Theoretical and Experimental Investigation into the Surface Roughness of Small-Hole EDM
Authors: Li Chang He , Han Zhen Lu , Li Lin Gang , Liu Guo Yu
Published: February 2011

The characteristic physical properties of titanium alloy materials of the electrical discharge machining (EDM) small hole is studied theoretically and experimentally. From the theory of EDM, based on the phenomenon of microcosmic surface on EDM small hole, the model of surface roughness is built, and the regulation between roughness and pulse width, peak electric current was analyzed, and the roughness empiric formula is developed by use of dyadic linear regression method. Furthermore, by computer simulation technology with established formula the results are derived for other people to public data simulation. After being simulated, the results show that the established model in this paper can accurately forecast the value of processing roughness Ra of commonly used in the processing parameters within the framework, provides a useful complement to titanium alloys for processing the theoretical study and practical application.
Study on the Key Position of the Trailer House Vacuum Insulation Materials in Cold Regions
Authors: Han Hou De , Kan An Kang , Geng Jin Liang
Published: February 2011

According to thermal comfort and energy conservation of trailer house, it analyzes the heat transfer characteristics about envelop enclosure of trailer house in cold regions. And it is got by the method of non-steady state heat conduction from two aspects, that is, the heat conduction and heat storage of envelop enclosure. It gets the method to calculate heat load of envelop enclosure and the conclusion that the vacuum insulation panel located inside the enclosure of house is more suitable in cold regions.
QoS-Aware Web Services Composition: A Cooperate Optimization Approach
Authors: Li Hai Feng
Published: February 2011

Existing Web service optimal combination approach is mainly focused on single tasks using “selfish” behavior to pursue optimal solutions. This causes conflicts because many concurrent tasks compete for limited optimal resources, reducing service quality in services. With the best reply function of quantified task conflicts and game theory as bases, this paper establishes a mathematical model depicting the competitive relationship between multitasks and Web service under QoS constraints, and guarantees that every task can obtain optimal utility services considering other task combination strategies. Moreover, an iterative algorithm which reaches the Nash equilibrium is also proposed, and all tasks attain utility optimization under conflicting environments. Experimental analyses show that the approach can considerably enhance the actual utility of all tasks compared with existing Web services combinatorial methods.
Apllication of Computer Technology for Automatic Weeding System
Authors: Jiang Zheng Rong , Li Zheng Xi
Published: February 2011

This paper presents the theory of computer automatic weed identification , some methods are discussed in detail including spectrum analysis, color identification, texture assessment and figure analysis methods individually. Besides, the research situation in this field is reviewed and the application trend direction in our country is prospected.
Study on the Flow Behavior in Thin Cavity during Water-Assisted Injection Molding
Authors: Kuang Tang Qing , Han Kun
Published: February 2011

A numerical simulation model for the flow behavior of fluids in thin cavity during water assisted injection molding process is built up by adopting general Newtonian fluid model for the filling stage and non-Newtonian and compressible fluid model for the packing stage separately. Finite element/finite difference/control volume methods are adopted for the simulation of melt front, pressure variation at injection location, water thickness fraction and bulk temperature about a plate with trapezoidal cross-section. The simulated melt front location and shape have good agreement with experimental result. In comparison with the simulation results of conventional injection molding, it turns out that water assisted injection molding can obtain parts with low pressure requirement, perfect surface quality and rapid cooling.
A Fast Design Space Exploration Method for Reconfigurable Architecture Based on Loop Optimization
Authors: Zhang Dan , Zhao Rong Cai , Han Lin , Liang Wei Fang , Qu Jin , Liu Xiao Nan
Published: February 2011

Using FPGA for general-purpose computation has become a hot research topic in high-performance computing technologies. However, the complexity of design and resource of FPGA make applying a common approach to solve the problem with mixed constraints impossible. Aiming at familiar loop structure of the applications, a design space exploration method based on FPGA hardware constrains is proposed according to the FPGA chip features, which combines the features of the corresponding application to perform loop optimization for reducing the demand of memory. Experimental results show that the method significantly improves the rate of data reuse, reduces the times of external memory access, achieves parallel execution of multiple pipelining, and effectively improves the performance of applications implemented on FPGA.
Discussion on GPS-RTK Using in Undersea Topographic Survey
Authors: Zhu Yu Feng , Ding Xiao Li , Li Zhi Wei , Zhou Shi Jian
Published: February 2011

The advent of GPS technology creates a new high-tech avenue for ocean mapping. This paper mainly discusses the application of GPS-RTK technologies in undersea topographic survey. Taking the project of Yangkou man-made island in Nantong city as an example, discuss the particular application of sea mapping in under-water topographic survey. The main job and work procedure of GPS technologies in under-water topographic survey are introduced. Problems need to be cared during the procedure and how to solve them also are discussed. Feasibility analysis of RTK technologies in undersea topographic survey is also done in this paper.
Base on Honeywell Business FLEX® PKS™ Planning and Scheduling Optimization Engineering Study
Authors: Huang Zhi Hui , Kan Shu Lin , Yan Liang Wen , Li Jun
Published: February 2011

Honeywell Business FLEX® PKS™ is a manufacturing executive system(MES) which is applicable to the process manufacturing firm to unify the supply chain plan, the service and the production automation, transferring the company's service goal to the definite operation goal and realizing the multi-varieties, multi-batch, high quality and low cost of the production demand. This paper has investigated on the enterprise productive plan and scheduler module to realise the system optimizations and product quality improvement as well as some key technical strategies. The paper also made an analysis for the numerous resources entity and functional module of the overall system and formed a research subject on the theory relative to the reliability growth of the MES. The research on the case has a certain instruction function for the enterprises which are going to put the MES into accurate, real-time data improves the decision-making process, and the resulting decisions improve customer service for all related information.
The Drawing Analysis of the Three-Dimensional Shape Domain
Authors: Tang Zhi , Zhang Yu
Published: February 2011

Through the research of the visualization of the human-based three-dimensional shape domain, establish the three-dimensional spatial extent of human’s function space. And coordinate the difference of function space between individuals and groups. It is based on the morphological characteristics, physical features and psychological characteristics of human. Then achieve the match of the data of body and design parameters of products. Thus integrate ergonomics into the early process of design. And complete the change of the mode of space design from dimension driven to 3D human body model-driven. The research of human body’s domain will definite the way and standards of interaction space between men and machines. Thus the parameters of human body become precise, three-dimensional and instrumental. Solve the discord of relationship between people and objects, people and environment, performance and environment. To realize the expression of man’s functions in the product itself and the interaction with them.
Development of Embedded Linux CNC System Based on ARM9
Authors: Cao Shu Kun , Wang Chang Lei , Zhang Hui , Lv Jie , Wu Chang Zhong
Published: February 2011

Five-axis machining area of free surface is proposed by based on ARM9 and Linux open CNC system's overall structure of the CNC system hardware and software architecture. The system adopts the mode of the host computer PC, the lower computer ARM9 development board. PC completes the model of space surface and generates tool path by Simultaneous Multi-objective Optimization Algorithm on Free-form Surface Five-Axis Machining Tool Path and Tool Posture. The lower computer applies MYSQL database to storage and manage cutter location point information. Other modules access the database through ODBC standard interface. ARM9and PC utilize the way of cross-platform socket data transmission, the stepper motors is controlled by the way of constant acceleration - deceleration.
Vendor’s Conduct and Contract Mechanism in IT Outsourcing Based on Information Inferiority
Authors: Zhang Shou He , Huang Wen Jie
Published: February 2011

In IT outsourcing, contract defects often cause outsourcing failure. Many client firms do not know well how to design the contract because they have no way to access private information of vendors, so vendors are likely to conduct out of constraint. This work combined relational contract with conventional one to establish an integral management mechanism. It at first gave the cost-increment analysis method to improve relational contract design so that it would facilitate outsourcing contract to work efficiently. Then analyzed the relation between vendor profit-gaining and its varied conducts, and built up the method of contract design to allow vendor gaining profit only when it conducts following its true types. In the method, the private information was sorted into a variety of conduct types and universal decision was found out aiming all the types. The mechanism effectively incents and constrains vendors without relying on private information.
Estimation of Curing Profile's Parameters for Flip Chip Packaging Using DSC and TGA
Authors: Kornain Zainudin , Jalar A. , Rasid Rozaidi , Foong C.S. , Wong T.L.
Published: February 2011

This paper presents the method to estimate curing profile's parameters for curing process of Moisture Resistance Cyanate Ester (MRCE) based underfill used in Flip Chip Ceramic Ball Grid Array (FC-CBGA). The two steps curing profile was found to eliminate voids formation in underfill during curing process. The important parameters in two steps curing profile such as first fixed temperature and duration of second temperature rise were estimated by superimposed of cure initiation curve and weight percentage loss curve of underfill epoxy material. Differential Scanning Calorimeter (DSC) analysis was carried out to characterize the cure kinetics reaction of underfill epoxy and produced the cure initiation curve. Thermal Gravimetric Analysis (TGA) was performed to characterize the weight loss of underfill and produced the weight loss curve. It was estimated that the first fixed temperature and duration of second temperature rise for two steps curing profile were 100 oC and 60-80 minutes respectively. The simulation experiment was conducted to verify the profile and no voids formation observed along this curing process.
A Component Model Supporting Dynamic Evolution of Internetware
Authors: Yue Yang , Zeng Guang Ping
Published: February 2011

Aiming at the forward topics of self-adapting Internetware, relying on the practical software engineering technology and previous research achievements of tackling key problems of SoftMan, the paper puts forward a novel component model ——SMC(SoftMan Component), which processes reflectivity, opening, adapting and supporting nested assembly and self-adjusting its internal architecture. Furthermore, the basic design specifications of APIs are described in detail. By the special structure of Component Body, SMC forms a hierarchical management domain which is of explicit constraint of father-child between component and its children, and thus it flexibly integrates control mechanisms for sub-components, such as interface introspection, lifecycle, interaction binding, dynamic configuration, etc., into its pluggable controllers so as to be endowed with the ability to change its behavior and architecture when the application must evolve to cope with user requirements and new context. Initial experiments demonstrate that SMC can give effective support for dynamic reconfiguration during running, and it takes on own technical characteristics compared with other component models.
Research on Stochastic Model and Simulation for Sorted-Storage S-Type Manual Order Picking
Authors: Zhu Jie , Guo Jian , Zhou Li
Published: February 2011

The key optimal goal of manual order picking system is shortest picker route, thereby best times. Picker route stochastic model under sorted storage S-type picking for logistics distribution center manual order picking is built. It makes model approximation calculation and simulation result under three order arrival frequencies and space ratio. It is stated that well approximation between model and simulation results under the condition of permission difference are obtained. The model lays the foundation for building stochastic service system model of distribution center manual order picking.
High Mobility Ge-Based CMOS Device Technologies
Authors: Takagi Shinichi , Dissanayake Sanjeewa , Takenaka Mitsuru
Published: February 2011

In this paper, we report on critical issues and possible solutions for realizing Ge MOSFETs on the Si platform. The main critical objectives in regard to Ge MOSFETs are (1) formation of high quality Ge channel layers on Si substrates (2) MIS gate stacks with much smaller EOT and interface defects (3) superior source/drain junction technology (4) combination of mobility booster technologies such as surface orientation and strain. We demonstrate that GeO2/Ge MOS interfaces can provide superior interface properties, leading to high hole and electron mobility. It is also shown that a gas phase doping technique is promising for forming superior n+/p junctions, which is critical for obtaining Ge nMOSFETs. Also, the importance of surface orientation engineering on the further mobility enhancement of Ge CMOS is addressed.
Development of New Methods for Fine-Wiring in Si Using a Wet Catalytic Reaction
Authors: Lee Chia Lung , Sugita Tomohiko , Tatsumi Koji , Ikeda Shigeru , Matsumura Michio
Published: February 2011

Using a new wet process based on a catalytic reaction, pores and grooves were formed in Si using Au, Pt, or Ag as the catalyst. The diameter of the pore can be as small as 50 nm. However, to produce wiring in Si wafers, we primarily formed pores with a diameter of about 5 μm. These pores were filled with Cu by electrochemical plating, forming Cu wires developed to the wafer surface. In the process, the catalyst particles remaining at the bottom of the pore acted as seeds for the deposition of Cu and helped fill the pores without the formation of voids. In order to control the position of pores and grooves formed in Si, methods using catalytic electrodes were also developed.
Optical Response of Si-Quantum-Dots/NiSi-Nanodots Stack Hybrid Floating Gate in MOS Structures
Authors: Morisawa Naoya , Ikeda Mitsuhisa , Makihara Katsunori , Miyazaki Seiichi
Published: February 2011

We have studied the effect of 1310 nm light irradiation on the charge distribution of a hybrid floating gate consisting of silicon quantum dots (Si-QDs) and NiSi Nanodots (NiSi-NDs) in MOS capacitors. The light irradiation resulted in reduced flat-band voltage shifts of the MOS capacitors in comparison to the shift in the dark. This result can be interpreted in terms of the shift of the charge centroid toward the gate side in the hybrid floating gate caused by the photoexcitation of electrons in NiSi-NDs and the subsequent electron tunneling to Si-QDs. The capacitance of the MOS capacitors at constant gate biases was modulated with pulsed light irradiation. When the light irradiation was turned off, capacitance recovered to its level in the dark, indicating that the photoexited charges were transferred between the Si-QDs and the NiSi-NDs without being emitted to the Si substrate and gate electrode.
Impact of Self-Heating Effect on the Electrical Characteristics of Nanoscale Devices
Authors: Kamakura Yoshinari , Zushi Tomofumi , Watanabe Takanobu , Mori Nobuya , Taniguchi Kenji
Published: February 2011

Hot phonon generation and its impact on the current conduction in a nanoscale Si-device are investigated using a Monte Carlo simulation technique. In the quasi-ballistic transport regime, electrons injected from the source lose their energies mainly by emitting optical phonons in the drain. Due to the slow group velocity of the optical phonons, the efficiency of the heat dissipation is so poor that a region with a nonequilibrium phonon distribution, i.e., a hot spot, is created. In this study, we have implemented the hot phonon effect in an ensemble Monte Carlo simulator for the electron transport, and carried out the steady state simulations. Although it is confirmed that the optical phonon temperature in the hot spot is larger than that of acoustic phonons by > 100 K, the electron current density is not significantly affected. The local heating would degrade the hot electron cooling efficiency and the parasitic resistance in the drain, but they have a minor impact on the quasi-ballistic electron transport from the source to the drain.
Microscopic Structure of Directly Bonded Silicon Substrates
Authors: Kato Tetsuji , Ohara Yuji , Ueda Takaya , Kikkawa Jun , Nakamura Yoshiaki , Sakai Akira , Nakatsuka Osamu , Ogawa Masaki , Zaima Shigeaki , Toyoda Eiji , Isogai Hiromichi , Senda Takeshi , Izunome Kouji , Tajiri Hiroo , Sakata Osamu , Kimura Shigeru
Published: February 2011

Using X-ray microdiffraction (XRMD) and transmission electron microscopy (TEM) techniques, we have investigated the microscopic structure of Si(011)/Si(001) direct silicon bonding (DSB) substrates. XRMD was performed to measure the local lattice spacing and tilting in the samples before and after oxide out-diffusion annealing. Diffraction analyses for (022) lattice planes with two orthogonal in-plane directions of X-ray incidence revealed anisotropic domain textures in the Si(011) layer. Such anisotropy was also confirmed by TEM in the morphology at the Si(011)/Si(001) bonded interface. The anisotropic crystallinity is discussed on the basis of interfacial defect structures which are proper to the DSB substrate.
Formation of Nanotubes of Carbon by Joule Heating of Carbon-Contaminated Si Nanochains
Authors: Kohno Hideo , Nogami Takafumi
Published: February 2011

We report a new route to fabricating carbon nanotubes and nanotube interconnects. Insulating Si nanochains covered with hydrocarbon, which are a kind of Si nanowire, can be transformed into distorted nanotubes of carbon by Joule heating. Transmission electron microscopy observations of the transformation reveal that first a surface carbon shell is formed, and then oxide evaporates by Joule heating forming a nanotube.
Photoluminescence Characteristics of Ultra-Thin Silicon-on-Insulator at Low Temperatures
Authors: Sakurai Yoko , Nomura Shintaro , Shiraishi Kenji , Ohmori Kenji , Yamada Keisaku
Published: February 2011

We have investigated C-V and photoluminescence (PL) characteristics of ultra-thin silicon-on-insulator (SOI) samples. Thickness dependence of a free exciton (FE) PL and an electron-hole droplet (EHD) PL has been investigated. We have found a remarkable enhancement of an EHD PL with decrease in the thickness of SOI samples.
Investigation about I-V Characteristics in a New Electronic Structure Model of the Ohmic Contact for Future Nano-Scale Ohmic Contact
Authors: Takada Yukihiro , Muraguchi Masakazu , Endoh Tetsuo , Nomura Shintaro , Shiraishi Kenji
Published: February 2011

Ohmic contacts are crucial for both device applications and the study of fundamental physics. From the perspective of device scaling trends, nano-scale Ohmic contacts are indispensable for future LSI technologies such as metallic source and drain contacts. In this study, we investigate the I-V characteristics using a varying discrete level distribution based on our previously-proposed model. Our calculated results show that linear I-V properties can be obtained from uniform discrete level distributions.
Collective Electron Tunneling Model in Si-Nano Dot Floating Gate MOS Structure
Authors: Muraguchi Masakazu , Sakurai Yoko , Takada Yukihiro , Shigeta Yasuteru , Ikeda Mitsuhisa , Makihara Katsunori , Miyazaki Seiichi , Nomura Shintaro , Shiraishi Kenji , Endoh Tetsuo
Published: February 2011

We study the sweep speed dependence of electron injection voltage in Si-Nano-Dots (Si-NDs) floating gate MOS Capacitor by using our collective tunneling model, which models the tunneling between two-dimensional electron gas (2DEG) and the Si-NDs. We clarify the sweep speed dependence of electron injection energy with a numerical calculation based on our collective tunneling model, that we developed to emulate the experiment in this system, and obtained a new insight into the origin of sweep speed dependence. We revealed that our model can reproduce the sweep speed dependence of electron tunneling. This insight is useful for designing future nano-electronic devices.
Controlled Synthesis of Carbon Nanowalls for Carbon Channel Engineering
Authors: Kondo Hiroki , Hori Masaru , Takeuchi Wakana , Hiramatsu Mineo
Published: February 2011

This study investigates the growth mechanisms of carbon nanowalls (CNWs), which are two-dimensional carbon structures that consist of stacked graphene sheets and that stand vertically on substrates. Factors that determine their morphological and electrical properties were studied using two plasma-enhanced chemical vapor deposition (PECVD) systems that permit the densities and energies of radicals and ions to be precisely controlled. For CNW growth using a C2F6/H2 plasma, the CNW growth rate decreased when the total pressure was increased from 13.3 to 80 Pa during growth. Raman spectroscopy and scanning electron microscopy revealed that the CNW crystallinity increases and the CNW density decreases with increasing total pressure. This is attributed to an increasing amount of H radicals in the growth ambient with increasing total pressure. During the initial stages of CNW growth using a multibeam PECVD system with CFx, hydrogen radicals, and Ar ions, CNWs were formed only for Ar+-ion fluxes of 3.3 to 3.8 A/cm2 and energies of 200 to 250 eV. Although attachment of CFx radicals and CNW growth require ion bombardment, if the flux or energy of ion bombardment is too high CNW growth will be inhibited due to etching and excessive carbon deposition. Semiconducting CNWs with n-type characteristics can be formed by adding N2 gas to the C2F6/H2 plasma. Furthermore, carrier concentrations of n-type CNWs can be controlled by nitrogen doping.
Composite Fracture: Getting to the Heart of the Matter
Authors: Beaumont Peter W.R.
Published: February 2011

The demands made on structural composite materials in modern design are increasingly stringent. Greater performance, lower costs, increased reliability and safety all require that the design engineer knows more and more of the material systems available. Bringing together new knowledge contained in constitutive models of continuum design and empirical information from a girth of experience is proving to be difficult because the number of service and process variables required for sophisticated, optimal design is becoming increasingly larger. Understanding Structural Integrity (SI) provides the key to the successful design, certification, and safety of large composite structures and engineering composite materials. This is because SI analysis treats simultaneously the design, the materials used, figures out how best components and parts are joined, and takes service duty into account. But predicting precisely where a crack will develop in a material under stress and exactly when in time catastrophic failure of the structure will occur remains an unsolved mystery.
Sugar Palm Fibre-Reinforced Unsaturated Polyester Composite Interface Characterisation by Pull-Out Test
Authors: Leman Zulkiflle , Sapuan S.M. , Suppiah S.
Published: February 2011

Polymer composites using natural fibres as the reinforcing agents have found their use in many applications. However, they do suffer from a few limitations, due to the hydrophilicity of the natural fibres which results in low compatibility with the hydrophobic polymer matrices. This paper aims to determine the best sugar palm (Arenga pinnata) fibre surface treatment to improve the fibre-matrix interfacial adhesion. Fibre surface modifications were carried out by water retting process where the fibres were immersed in sea water, pond water and sewage water for the period of 30 days. The test samples were fabricated by placing a single fibre in an unsaturated polyester resin. Single-fibre pull-out tests showed that freshwater-treated fibres possessed the highest interfacial shear strength, followed by untreated fibres, sewage water-treated fibres, and sea water-treated fibres. Further surface analyses of the samples were performed using a Scanning Electron Microscope (SEM) and an Energy Dispersive X-ray Spectroscopy (EDS) system.
Doping of Palladium in Silica Nanofibers via Electrospinning and Sol-Gel Synthesize as Hydrogen Storage Material
Authors: Shahgaldi Samaneh , Yaakob Zahira , Khadem Dariush Jafar , Wan Daud Wan Ramli , Majlan Edy Herianto
Published: February 2011

In recent years, one dimensional nanostructure, nanowires, nanofibers with unique properties have been a subject of intense research due to reduction of devise dimension, potential properties from the re-arrangement at the molecular level and high surface area. There are many methods for synthesize such as laser ablation, chemical vapour deposition, solution method micro pulling down method but all these method faced to the major disadvantages of being complicated with long wasting time and relatively high expense . The electrospinning recently used for producing ceramic, metal, and carbon nanofibers. In this report, we incorporate palladium into silica nanofibers for the first time, and the effect of doping of palladium into the silica nanofibers is investigated. The different ratio of palladium to silica and comparing with silica nanofibers is also reported. The composition, morphology, structure and surface area of silica, and silica palladium nanofibers were investigated by thermo gravimetric analysis (TGA), x-ray diffraction (XRD), scanning electron microscopy (SEM),Fourier transform infrared spectroscopy (FT-IR), and Micromeriics. To the best of our knowledge, investigation on characteristic on Silica palladium nanofibers has not been reported up to now. The result reveal that the silica nanofibers compare to silica doped with palladium have lower diameter, and also by increasing the temperature above 600 °C, the reduction in length of nanofibers happened. High surface area of silica palladium nanofibers can be one of the promising materials for hydrogen storage.
Flexural Mechanical Characteristic of Sawdust and Chipwood Filled Epoxy Composites
Authors: Hisham S. , Faieza A.A. , Ismail N. , Sapuan S.M. , Ibrahim M.S.
Published: February 2011

A study was conducted with the objective of gathering the information through flexural (three-point bending) testing. This research presents the testing results concerning the mechanical properties, modulus of elasticity (MOE) and modulus of rupture (MOR) of natural fiber reinforced composite. Resin were used as a matrix and untreated wood fibres contents 14% by weight as a filler treatment parameters to obtain better compatibility involving wood fibres Sawdust (SW) and Chipwood (CW) and epoxy. The feasibility of processing the composite prepared manually from waste wood and epoxy using open molding was investigated. The tests that have been conducted are in according to ASTM (D790-97) for flexural properties test method. Statistical analysis using ANOVA one way and two way showed that the differences of results obtained from those SW and CW fiber composite samples are significant, which confirm a very firm mechanical performance of the composites through flexural tests. This shows the producing a good quality of SW and CW fibre composite which maybe can use for furniture utilities.
Simulation of Thermoset Injection for Bulk Moulding Compounds (BMC)
Authors: Arifin Mohd Khairol A. , Sulaiman Shamsuddin , Baharudin B.T. Hang Tuah , Hong Tang Sai , Sreenivasan S.
Published: February 2011

This paper discusses about the simulation of the process of injection moulding for thermoset materials namely Bulk Moulding Compounds (BMC). BMC is a polyester resin based compound with glass fibre additives. In this paper a complex part was used to simulate and obtain the parameters for moulding BMC. Autodesk Moldflow Plastics Insight was used to run the simulation. Two main parameters i.e. Injection time and mould temperature were considered. Six different sets of parameters were used and the settings were optimized. The obtained optimized settings are 15.08 seconds and 145°C. The obtained parameters were then applied and the actual part was tested using an injection-moulding machine. After the simulation, changes were also made to the actual mould to improve the moulding conditions. Extra air vents were added at the problematic areas to ease the flow. There was an average variance of 7% which was thought to be acceptable as the simulation considers the ideal condition, where as there may be external factors such as the machine wear and tear during the actual moulding of the part. It can be said that the simulation was run successfully and tested during actual moulding.
Flutter Analysis of a Hybrid Plate-Like Fiber-Reinforced Composite Wing
Authors: Abdul Majid Dayang Laila Abang , Basri Shahnor , Varatharajoo Renuganth , Attaran A.H.
Published: February 2011

The aeroelastic flutter of a laminated hybrid composite wing was investigated. The composite wing was modelled as composite plates and the aeroelastic analysis has been carried out in the frequency-domain. Pre-determined fiber orientation of a 3-layers carbon/epoxy and glass/epoxy laminated plate has been employed with various aspect ratios. The modal approach and the Doublet-lattice Method (DLM) have been used herein to calculate the normal modes and the unsteady aerodynamics of the plate. The structural and aerodynamic models were connected using surface splines and the flutter speed has been calculated using the p-k method that provides the eigenvalues at different air densities and airstream velocities. The study showed that it is imperative that the carbon/epoxy should be employed in the outermost layers in order to improve the flutter speed and flutter frequency.