Security and privacy in RFID and applications in telemedicine

Radio frequency identification systems have many applications in manufacturing, supply chain management, inventory control, and telemedicine. In an RFID system, products and objects are given RFID tags to identify themselves. However, security and privacy issues pose significant challenges on these systems. In this article we first briefly introduce RFID systems. Then two RFID applications in telemedicine are proposed: studying supply and demand of doctors, nurses, and patients in hospitals and healthcare, and developing mobile telemedicine services. The security and privacy issues of RFID, and their solutions are discussed as well.     

Fluoride and apatite formation in vivo and in vitro

In recent years, the biomineralization process has attracted much interest from academics and industries for potential technological application. The rule in biomineralization is to have a variety of interfaces and surfaces which can act as nucleators. The ultimate step in any biomineralization process, i.e. the deposition of mineral, must conform to the driving forces operating on the system. A new paradigm in the assessment of the driving force for biomineralization is that a variety of ions existing in the mineralizing milieu are not a bystander, but are instead an active player that directly regulates the precipitation process and nature of biogenic apatites. Thus, the most putative stoichiometric model of a biomineral is (Ca)(5-x)(Mg)q(Na)u(HPO4)v(CO3)w(PO4)(3-y)(OH,F)(1-z). Fluoride participates in many aspects of calcium phosphate formation in vivo and has enormous effects on its process and on the nature and properties of the final products. In the development of biogenic apatites, fluoride ion in the mineralizing media is supposed to accelerate the hydrolysis of acidic precursor(s) and increase the growth rates by augmenting the driving force for precipitation. Inhibitory activities of ions and molecules are related to their adsorption onto the apatite surfaces. From theoretical and practical points of view, it is of paramount importance to elucidate and predict the effect and outcome of fluoride (accelerator) and inhibitors of biological relevance, because of their use in combination for healthcare in dentistry and medicine, e.g. prevention of dental caries and calculus deposition and in the formulation of antiosteoporosis treatments.     

Electrical ionization and breakdown in gaseous ethylene derivatives and in isoprene

Townsend primary and secondary ionization coefficients have been measured and sparking voltages deduced for di- and tri-methyl ethylene and for isoprene over a pressure range of 2 to 200 Torr and a parallel plate gap distance up to 1 cm yielding derived sparking voltages in excess of 500 000 V. The Townsend equation for ionization is found to be closely obeyed by the gases and vapours and the Townsend constants have been derived. A detailed analysis of the experimental results shows that progressive methyl substitution around the ethylene double bond influeneces the electrical characteristics less markedly than straight chain substitution, in line with further electrical data taken from other sources on hydrocarbons.     

IT安全化安全IT化--信息安全产业发展问题与思考

信息安全在IT业中的角色演变 在当今信息时代,信息技术日新月异,信息产业已经成为拉动GDP增长的第一支柱产业,并以每年20%—30％的速度迅猛发展。其发展过程也经历了从传统IT向新型IT的转变,其中一个重要的转变因素便是信息安全。 1.传统IT与信息安全的关系。传统IT涵盖了五大类:通信、网络、计算机、软件、电子材料及元器件。这五类IT行业本身的发展一度呈现结构失衡:一方面过度投资到“信息高速公     

Radiocommunication and control in mines and tunnels

A new system of electromagnetic propagation by means of a coaxial cable designed for radiocommunication in mines and tunnels is described. Theoretical results and their application to the radiocontrol of a winch are presented.     

《信号与系统》中卷积教学思考以及在AI技术中的应用

《信号与系统》课程是电子信息类专业的专业基础课程,本课程是以数学理论引出信号处理的基本方法,进一步在工程应用中应用。本文针对该课程的理论性强和工程应用背景厚等特点,通过对卷积的思考及拓展,举例阐述卷积的计算过程及含义,通过在教学中引入前沿的科技热点,对传统的教学进行改革。激发学生探究基本概念的本质,引导学生积极思考,进一步提高教学效果。     

网络化智能传感器及其在航空航天领域中的应用

目前,我国航空航天领域中测控系统仍然采用传统的测量模式,与国外先进测试水平有着很大差距,其中的差距之一就是传感器缺少智能化、网络化功能。本文首先介绍了智能传感器的概念、功能,然后概述了智能传感器在网络化方面的进展和研究现状,之后论述了网络化智能传感器在航空航天领域中的研究和应用情况。从其研究和应用角度看,美国在智能传感器网络化方面已经开展了多年研究,并且取得了很大进展,很多研究结果都已经得到应用,我国需要积极开展此项方面的研究工作,以提高我国航空航天领域的测试水平,以便更好适应航空航天事业的发展。     

多媒体厅室电声设计中的声场分布与测量

研究了大、中学校多媒体教室及报告厅常用的主声源及声场分布,给出了上述教室及报告厅电声环境构建中设计、测量的简单实用方法。对听音者的听音效果及质量追求有较为重要的实际意义。     

Periodic bandgap and effective dielectric materials in electromagnetics: characterization and applications in nanocavities and waveguides

The main objectives of this paper are to characterize and develop insight into the performance of photonic bandgap (PBG) periodic dielectric materials and to integrate the results into some novel applications. A powerful computational engine utilizing the finite-difference time-domain technique with periodic boundary conditions/perfectly matched layers integrated with Prony's method is applied to provide an in-depth look at the physics of PBG/periodic bandgap structures. Next, the results are incorporated into two classes of applications in the areas of nanocavity lasers and guidance of electromagnetic (EM) waves in sharp bends. A two-dimensional PBG structure with finite thickness is presented to strongly localize the EM waves in three directions and design a high-Q nanocavity laser. It is shown that the periodic PBG/total internal reflections remarkably trap the EM waves inside the defect region. The effect of the number of periodic cells and defect's dielectric constant on the Q of structure is investigated. It has been found that a seven-layer PBG with a dielectric impurity defect can be used in the design of a laser with a Q as high as 1050. Additionally, potential applications of the PBG structures for guiding the EM waves in sharp bends, namely, 90/spl deg/ and 60/spl deg/ channels are demonstrated. It is shown that shaping the bend by introducing small holes can noticeably improve the guidance of the waves at the bends and channel the EM waves with great efficiency. A comparative study between PBG and effective dielectric materials in controlling the EM waves is also provided and it is observed that the novel characteristics of the PBG cannot be modeled using the effective material for the frequencies within the bandgap.     

非均匀介质中的场与波：理论及其在电测井中的应用

本文综述了非均匀介质中场与波理论近年来的研究进展及其应用成果，着重介绍了非均匀介质中的电磁场正演分析和反演计算中的各种高效数值方法，以及它们在电法测井数值模拟和成象研究中的成功应用。     

Interrelation of erythropoiesis and lymphopoiesis in experimental infectious processes and in viral leukemogenesis

Interrelation of erythropoiesis and immune response was studied in mice of various lines infected with mycoplasma species, Shigella flexneri 2a and Rauscher leukemia virus (R-MLV). Intensity of erythropoiesis was estimated by the endocolonization data of sublethally irradiated mice and 59Fe incorporation, while immune reactivity--by generation of splenic antibody-forming cells in response to immunization with sheep erythrocytes. The inverse correlation between the ability of infectious agents to enhance erythropoiesis and to depress immune reactivity was found. Enhanced state of erythropoiesis was observed with concomitant diminished immune response when R-MLV and M. arthritidis or S. flexneri 2a (strain 516) were used. There was a positive correlation between the ability of mycoplasmae and shigellae to activate erythropoiesis and their stimulatory effect on R-MLV reproduction tested by the spleen focus-forming units (SFFU) enumeration technique. Possible role of mononuclear phagocytes in the phenomena mentioned is discussed.     

Effects of quantization and sampling in digital correlators and in power spectral estimation

An efficient method for calculating the mean values and standard deviations of spectral estimates and decision variables is described which utilizes Kellogg's numerical method for calculating correlation functions of quantized random waveforms. The method and computer program are designed to explore the interaction between sampling (i.e., aliasing) and quantization effects.     

新形势下广播影视科技情报工作的变革与创新

本文论述了随着网络时代的到来和广播影视行业产业化、集团化改革步伐的加快，科技情报工作者要把握优势、冷静思考、沉着应对，引入新的管理理论，加强科技情报队伍的业务水平和工作素养，不断开拓创新，更好地为广播影视事业发展服务。     

计算机及数学软件在高校数学教学中的应用

经过多年的不断发展，计算机及数学软件已经成为一种十分重要的数学工具，深刻地影响着人们的生活、工作等方面。在教育方面，其效果与功能一直是教育界讨论的热点。文中着重探讨了计算机和数学软件在高校数学教学中的应用，以期对高校教育工作者有所帮助。     

PCB行业空调与动力系统节能探索与实践

文章结合自身实践经验对PCB行业的空调与动力系统节能措施进行了介绍和分析。     

Recent activities in antennas and propagation in Japan

Activities since August 1989 are covered. Included are antennas for mobile communication, multibeam earth station antennas, satellite-borne antennas for communication, and for earth remote sensing, direct broadcast satellite antennas, and propagation studies for land mobile radio, mobile satellite systems, fixed satellite systems, and terrestrial propagation     

Status and trends in modern micro- and nanotechnology

The recent development from micro- to nanotechnology enables new ideas and new physical effects to be implemented in both conventional and novel devices. Examples of fast developing fields in this context are electronic, photonic and magnetic components for sensor, memory, and logic applications. Optical lithography, the traditional path of patterning, is supplemented with sophisticated methods to access the nanoworld.     

Trends and Perspectives in Image and Video Coding

The objective of the paper is to provide an overview on recent trends and future perspectives in image and video coding. Here, I review the rapid development in the field during the past 40 years and outline current state-of-the art strategies for coding images and videos. These and other coding algorithms are discussed in the context of international JPEG, JPEG 2000, MPEG-1/2/4, and H.261/3/4 standards. Novel techniques targeted at achieving higher compression gains, error robustness, and network/device adaptability are described and discussed.     

SIP及其在软交换网络和IMS中的应用

介绍了SIP(session initiation protocol)协议的特点、功能和结构等,从路由、网络结构和典型呼叫流程方面研究分析SIP在软交换网络和IMS中的应用,最后对SIP的未来做出了展望。