识别人类的手势的机器人

位于新加坡的A*STAR讯通信研究所的研究人员已经创造了手势识别软件,这种软件可以让机器人经过短期的培训后,便能正确、迅速地识别人类的手势。Rui Yan所领导的研究小组采用了局域网络(LAN),这是一个具有认知功能的内存模型,旨在开发一个可以与社交机器人沟通的全新系统。训练机器人识别和回应人的手势是十分困难     

韩国国内的半导体的投资

过去十年问,韩国的投资稳步增长,尤其是存储市场方面三星和现代频具实力。自从2002年开始,300mm硅片的生产能力迅速增长,目前预计2011年300mm硅片生产能力增     

计算机病毒的预防的思考

计算机病毒随着计算机的普及也渗透到信息化办公的各个领域,带给计算机操作系统难以防范的困扰。为使计算机信息安全有保障,研讨计算机的病毒的防范措施迫在眉睫。针对计算机病毒如何预防进行探究,并分析应对措施。     

基于FPGA的单片机的系统的设计

本文在阐述可编程逻辑器件特点及其发展趋势的基础上,利用EDA的硬件和软件技术,研究和设计了基于FPGA的8051单片机的片上系统。本文采用VHDL语言,应用先进的自顶向下的设计方法,在Active—HDL5．1编程环境下,应用层次化的设计思路,模块化的设计方法进行设计。     

艺术的都市人 都市人的艺术

<正>自古以来,城市不仅是人类财富与权利的中心,更是人类智慧与文明的汇集地。一代又一代的都市人不仅创造着物质财富,更在城市文化的熏陶下,创造了属于自己的灿烂精神文明。艺术是人类文明创造出的一朵奇葩,自城市诞生以来,它就一直伴随着都市人。从古代城市的辉煌遗迹到现代都市的热闹繁华,虽然都市人和艺术都经历着时代的变迁和发展,但是,都市人与艺术之间的密切关系却未曾改变。都市人创造了属于他们自己的艺术,而艺术也带给了     

石狮充满活力的的服装名城

石狮是一座时尚动感的城市。它位于福建东南沿海,地处文化历史名城泉州与经济特区厦门之间,三面临海,海岸线长67公里,与台湾隔海相望。全市面积177．7平方公里,户籍人口312万人,外来人15140多万,海外侨胞30多万人。     

工业光纤的更好的经济效益

当美国国家航空航天局（NASA）兰利研究中心的研究人员观察电磁干扰如何潜在影响飞行导航和通信系统时,得到了一些惊人的结果。举个例子,来自一些超宽带信号的干扰可能会在没有预警的情况下突然消除飞机无线电。电磁干扰（EMI）也可能会导致无线电导航系统给出错误的读数。电磁干扰也可以影响距离测量设备,在某些情况下,读出的距离可能远离一整个海里。也许最令人担忧的是,严重的电磁干扰会中断空中防撞系统显示屏上的飞机图像。     

有关消防工程的给水设备的设计的分析

市场经济下,经济科技不断发展,现代工程项目建设更为先进,其结构设计也趋于复杂化,给消防工程建设增加了难度,所以对消防工程中的给水设备提出了更高的要求,给水系统中的设备主要有水池、水高位水箱、泵接合器、消防栓等。本文主要分析给水设备的设计要求,使其能够符合消防工程的应用。     

解读中性服饰文化——女性的服饰的男性化与男性的服饰的女性化

对于现代人而言,服装不仅仅是一种物质上的满足,更重要的是精神上的需求,服装是人类高度文明的重要组成部分之一。近年来,随着思想观念的日渐开放和多元化,中性化服饰风潮席卷时尚界,成为引领大众消费的一种独特的服装风格。本文先对中性化服装的形成与发展进行分析,接着从中性服饰的审美价值及中性服装外观心理意义两方面对中性服饰文化进行解读。     

完美的TAIDEN 完美的服务

深圳市台电实业有限公司成立于1996年,专门从事现代会议系统设备的研发、设计、生产及世界范围的销售。台电公司经过多年不懈的努力,创出了“TAIDEN”这一民族品牌,取得了一系列具有自主知识产权的国际领先的会议系统的核心技术。TAIDEN产品系列达8种,近300个品种;并能提供从小型会议讨论到大型国际会议全系列会议系统解决方案,成为全球领先的现代会议系统设备制造商之一。     

Fundamental study of adhesion of ice to cooling solid surface (Discussion on influence of copper oxide layer on ice adhesion force)

In many situations, ice often adheres to a cooling solid surface, frequently causing serious accidents. It is critical to clarify the mechanism of ice adhesion to the cooling surface in order to prevent ice adhesion. In a past study, the shearing stresses of two kinds of test plates with a copper surface having the higher thermal conductivity were measured. The shearing stress corresponds to ice adhesion force. Both shearing stresses were significantly different; however, the cause remains unclear.Therefore, the present study focuses on an oxide layer as the main factor causing the difference of both shearing stresses; the influence of the oxide layer formed on shearing stress was discussed. And in the removal and reformation processes of the oxide layer, the time variation of the shearing stress was clarified. Moreover, the relationship between the state of the copper surface and the shearing stress was also clarified by surface analysis.     

Quality Study of Honeycomb Core Shaping Without Wax Stabilization

Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.     

The Role of Misfit Dislocations in Strength Enhancement of Cu/Ni Microlaminates

This paper simulated the nanoindentations of Cu/Ni thin films with 2D Molecular Dynamics Simulations (MDS) and examined the effects of the misfit dislocations on the mechanical properties of the microlaminates. The misfit dislocation network plays an important role in strength enhancement of Cu/Ni microlaminates because of its resistance to glide dislocations. But the strengthening also relies on the wavelength, which is defined as the thickness of adjacent two layers in microlaminates. When the wavelength is less than the critical value λc, the stress concentration caused by the movement of misfit dislocations will make Cu/Ni microlaminates weaken. Also, the critical wavelength should be more than the depth at which the dislocation nucleates in the homogeneous layer.     

Effects of liquid refrigerant injection on the performance of a refrigeration system with an accumulator heat exchanger

Liquid refrigerant injection technique can be a very effective method for controlling subcooling and the compressor discharge temperature of a refrigeration system at high ambient temperatures. In this study, the effects of liquid refrigerant injection on the performance of a refrigeration system with an accumulator heat exchanger were investigated by varying the liquid injection rate at the conditions of constant expansion valve opening in the evaporator and constant total flow rate. During the tests, the ambient temperature was maintained at 43 °C. With the increase of the liquid injection rate, the subcooling at the inner heat exchanger outlet increased and the superheat at the accumulator outlet decreased. However, unacceptable results such as the increase of the compressor discharge pressure and decrease of the system performance were also observed depending on the control method applied. To obtain high system performance and reliability, optimum control methods for liquid injection in the accumulator heat exchanger are suggested. The liquid injection technique for the refrigeration system with an accumulator heat exchanger was found to be an effective method for controlling adequate subcooling and the compressor discharge temperature of the refrigeration system at high ambient temperatures.     

Development of Catalytic Converters Using Detonation Spraying

One of the trends in hydrogen power engineering is the development of devices for the preparation of synthesis gas by the catalytic reforming of a hydrocarbon feedstock. Studies show the advantages of catalytic converters based on a modular catalyst support with a honeycomb-type structure produced from a metal foil, both sides of which are coated with highly porous oxide ceramics. The drawback of this design is a poor ability of the coating to withstand high-temperature operating conditions. The coating may detach from the substrate because of the difference in thermal expansion coefficients between the metal foil and the ceramic coating. Besides, a corrosion of metal foil takes place. The result of the present study is the development and application of a two-step coating method, which allows significantly increasing the service life of the catalyst supports. At the first step, a low-porosity ceramic layer is deposited on a metal foil by detonation spraying. At the second step, a high-porosity layer of a ceramic catalyst is deposited from suspension. In this work, the peculiarities of the detonation spraying of the ceramic coating on a metal foil and the design of the obtained catalytic converter have been addressed.     

Charge optimisation study of a reversible water-to-water propane heat pump

This paper presents the results and conclusions regarding the optimisation of the charge obtained throughout a thorough development study performed with a reversible water-to-water heat pump using propane as refrigerant. The paper first describes the influence of the charge on the capacity and COP of the unit at given operating conditions and then analyses the causes of such influence. Then, the theoretical study carried out with a detailed mathematical model to estimate the amount of refrigerant in each part of the unit is discussed. The second part of the paper is devoted to analysing the influence of the design of the evaporator (BPHE with and without integrated orifice distributor) and the operating conditions on the optimal charge. Finally, the effect of employing a POE or a mineral oil for lubrication on both performance and optimal charge is discussed.     

Experimental investigation and numerical simulation on the hysteresis zone of a variable displacement wobble plate compressor

A test system with the variable displacement compressor (VDC) for automotive air conditioning system is built to study the changing rule of piston stroke length (PSL). It is found from our experiments that the critical suction pressure where the PSL starts to decrease is less than that where the PSL starts to increase for the same PSL; between the two critical lines, a hysteresis zone is formed, within which all the steady-state points fall and there is a multiple-valued relationship between VDC parameters; and the PSL is kept invariable when the VDC parameters change within the hysteresis zone. In order to find out the reason causing the hysteresis zone and to analyze the influence of the compressor parameters on the hysteresis zone, a steady-state mathematical model of VDC is developed and verified by our experimental data. The theoretical analysis indicates that the hysteresis zone is caused by the frictional forces among the moving components of VDC, and the greater the frictional forces, the broader the hysteresis zone and the larger the changing range of suction pressure. The influence of the discharge pressure and rotary speed on the hysteresis zone is that the hysteresis zone moves in the direction of the suction pressure decreasing along with the increase of the discharge pressure or rotary speed.     

CFD evaluating the influence of airflow on the thermocouple-measured temperature data during air-blasting chilling

A numerical investigation using a computational fluid dynamics (CFD) code is carried out to examine the influence of airflow on the thermocouple-measured temperature during air-blast chilling. A CFD model is developed to predict the temperature distribution and weight loss of the foods with and without the presence of thermocouples; the simulated temperature data are compared with experimental results. The comparison shows significant differences in the temperature results, especially near the surface of the foods being chilled. The study demonstrates that the temperature error depends not only on the length of the thermocouple remaining outside the product, but also the depth of the thermocouple inserted into the product. This study reveals a hidden source of experimental error and may help process engineers to better understand the phenomenon, and to correctly evaluate and examine their experimental and/or simulated temperature results for the air-blast chilling process.     

Effects of synthetic oil in a compression refrigeration system using R410A. Part II: quality of heat transfer and pressure losses within the heat exchangers

The consequences of the oil rejected by the compressor of a vapour-compression refrigeration system on the operation of the evaporator and condenser are analysed. The modelled prototype uses the mixture of HFC R410A and a synthetic polyolester (POE) oil. The rise of the amount of lubricant circulating in the system leads to a progressive change in the behaviour of the mixture of refrigerant and oil that, for the higher oil mass fraction, evolves like a zeotropic mixture. One also observes that the presence of lubricant is generally associated with a fall of the performances of the heat exchangers, except however in the evaporator where an optimum is observed when the quantity of oil is equal to 0.1% of the total mass of the mixture. Some conclusions are drawn about the choice of correlations for the calculation of the refrigerant side heat transfer coefficient in a plate evaporator.     

Analysis of refrigerant flow and deformation for a flexible short-tube using a finite element model

A finite element model was used to simulate single-phase flow of R-22 through flexible short-tubes. The numerical model included the fluid-structure interaction between the refrigerant and the deformation of the short-tube as upstream pressure was varied. The finite element model was developed using a commercially available finite element package. Short-tubes with moduli of elasticity ranging from 5513 to 9889 kPa were studied. Four upstream and downstream pressures were applied and the upstream subcooling was held at a constant value of 16.7 °C. Mass flow rates from the numerical model were compared to available published experimental results. The study showed that upon deformation the short-tube resembled the shape of a converging-diverging nozzle. Both tube inlet and outlet had a chamfered-like shape after deformation which reduced the pressure drop at the tube inlet. The smaller the modulus of the tube, the larger the chamfered-like angle at the inlet and the higher the pressure drop along the tube due to the higher tube contraction. The results illustrated that as the upstream pressure was increased by 45%, there was almost a 60% decrease in the flow area. The more flexible (5513 kPa) short-tube restricted the mass flow rate more than the most rigid (9889 kPa) short-tube used in this study. The mass flow rates estimated with the finite element model were as much as 14% higher than those from experimental results reported in the literature.