Emergency TeleOrthPaedics m-health system for wireless communication links

For the first time, a complete wireless and mobile emergency TeleOrthoPaedics system with field trials and expert opinion is presented. The system enables doctors in a remote area to obtain a second opinion from doctors in the hospital using secured wireless telecommunication networks. Doctors can exchange securely medical images and video as well as other important data, and thus perform remote consultations, fast and accurately using a user friendly interface, via a reliable and secure telemedicine system of low cost. The quality of the transmitted compressed (JPEG2000) images was measured using different metrics and doctors opinions. The results have shown that all metrics were within acceptable limits. The performance of the system was evaluated successfully under different wireless communication links based on real data.     

Calculation of parameters of a flat turbulent jet in a deflecting stream

On the basis of the solution of the problem of a flat turbulent jet in a deflecting stream obtained earlier by the author a method is suggested for calculating the parameters of the main section of such a jet with allowance for the rarefaction occurring behind it. The amount of rarefaction was determined from an experiment and is accounted for by a second empirical constant. The results of a calculation by the proposed method are in satisfactory agreement with the experimental data.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 25, No. 5, pp. 907-912, November, 1973.     

Impacts of impulse-based ultra-wideband data links on cooperative wireless ad hoc networks

The recently permitted unlicenced use of the regulated ultra-wideband (UWB) radio spectrum (regulated first by the US FCC in 2002 and subsequently by the standardisation bodies of EU and other major countries) provides wireless ad hoc networks a cheap and promising air-interface technology for their adopted wireless data links, thus offering the potential to greatly boost their applications. The impacts of such UWB data links, mainly the more likely adopted impulse-based UWB data links for low data rate applications, on the extensively developed cooperative wireless ad hoc networks are investigated. First, the authors investigate the diversity order of data transfer of each impulse-based UWB data link working in a corresponding fading channel, and give an approximate relationship between the diversity order and the channel model parameters (here the Saleh?Valenzuela model parameters); Secondly, the authors develop efficient cooperative and decentralised diversity schemes that can utilise the widely spread and independently distributed multiple paths of the fading UWB channels. Performance analysis and simulation studies show that proposed decentralised cooperative beamforming schemes can achieve full diversity and are more efficient than their decentralised cooperative routing counterparts.     

Particle temperature fluctuations in a turbulent stream

The question of temperature fluctuations of particles suspended in a turbulent stream of a radiating and scattering medium is analyzed.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 55, No. 5, pp. 731–735, November, 1988.     

Selectivity of an acoustic detector in a turbulent stream

Relationships obtained for piezoelectric systems are extended to an arbitrary kind of electroacoustic transducers. Expressions are obtained for the pulsation of transducers with an arbitrary distribution of oscillations over the detector surface.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 17, No. 3, pp. 416–422, September, 1969.     

无线数据通信在动力供水远程监控中的应用

文章针对工业供水中存在的实际问题,基于先进的无线数据通信技术,提出了一个解决方案——动力供水远程监控管理系统。通过介绍Mobitex技术,分析设计了远程监控系统的硬件构成,同时对数据通信中的通信协议进行了合理的改造处理,开发了满足系统功能要求的监控软件,最后对该系统的实践应用情况进行了分析。     

Randomised and distributed methods for reliable peer-to-peer data communication in wireless ad hoc networks

Peer-to-peer (P2P) communications have attracted a great deal of attention from the network research community in recent years. However, due to the fundamental limitations of wireless environments, providing reliable data availability for P2P applications over wireless ad hoc networks is still a major challenge. To address the problem, a distributed and randomised scheme based on self-avoiding walks is proposed. The scheme concatenates disparate network layers, with the goal of recovering from routing failures that disrupt P2P data accessibility. In addition, a probabilistic approach is presented that explores the tradeoffs between several system parameters. Some new analysis tools, such as path coupling, are utilised which provide a better understanding of the system's operations. That the proposed concepts and techniques make a significant contribution to the design of effective and efficient P2P applications in wireless ad hoc networks is believed.     

Temporal coherence of individual turbulent patterns in atmospheric seeing

We used a variation of the generalized scidar (scintillation detection and ranging) technique to examine the temporal coherence of turbulent patterns at different altitudes in the atmosphere above Palomar Observatory. This enables us to test the validity of a frozen turbulence hypothesis in the local reference frame of the moving atmosphere. The data set analyzed here contains three turbulent patterns, each at a different altitude, which remain internally coherent over time scales of 0.28-0.41 s. This measurement is significant, because it is made on a 5-m aperture, allowing moving patterns to be tracked over time scales longer than their own lifetimes.     

Method for reconstructing atmospheric optical parameters from the data of polarization lidar sensing

Inversion of polarization lidar sensing data based on the form of the lidar sensing equation with allowance for contributions from multiple-scattering calls for a priori information on the scattering phase matrix. In the present study the parameters of the Stokes vectors for various propagation media, including those with the scattering phase matrices that vary along the measuring range, are investigated. It is demonstrated that, in spaceborne lidar sensing, a simple parameterization of the multiple-scattering contribution is applicable and the polarization signal's characteristics depend mainly on the lidar and depolarization ratios, whereas differences in the angular dependences of the matrix components are no longer determining factors. An algorithm for simultaneous reconstruction of the profiles of the backscattering coefficient and depolarization and lidar ratios in an inhomogeneous medium is suggested. Specific features of the methods are analyzed for the examples of interpretation of lidar signal profiles calculated by the Monte Carlo method and are measured experimentally.     

Thermal diffusion in a turbulent water stream with gas bubbles

Results are shown of an experimental study concerning the heat transfer and the average temperature fields man effervescentgas-liquid stream. It is noted that an increase in the gas content brings about turbulent diffusion of heat across the entire stream section.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 24, No. 5, pp. 781–789, May, 1973.     

Heat transfer to turbulent stream in pipes under supercritical pressures

Experimental results are presented on heat transfer to several liquid hydrocarbons under supercritical pressures and pseudoboiling conditions. An empirical relation is proposed which generalizes these results.     

Analysis of spatial-temporal converters for all-optical communication links

We analyze parallel-to-serial transmitters and serial-to-parallel receivers that use ultrashort optical pulses to increase the bandwidth of a fiber-optic communication link. This method relies on real-time holographic material for conversion of information between spatial and temporal frequencies. The analysis reveals that the temporal output of the pulses will consist of chirped pulses, which has been verified experimentally. When the signal pulses are transmitted along with a reference pulse, the distortions of the received signal, caused by dispersion and other factors in the fiber, are canceled because of the phase-conjugation property of the receiver. This self-referencing scheme simplifies the receiver structure and ensures perfect timing for the serial-to-parallel conversion.     

A turbulent jet in a concurrent stream at a permeable surface

The average and pulsation velocity profiles are measured in a rectangular channel during combined pore-slot blowing. Universal functions are proposed which generalize the experimental data obtained in different cross sections and in a wide range of intensities of pore blowing.

     

Velocity profile in a turbulent boundary layer of a supersonic gas stream

A semiempirical equation is proposed for relating the coefficients of molecular and turbulent viscosity in the laminar sublayer and in the transition region. Simple formulas are derived for determining the velocity throughout the boundary layer and the frictional stress at the surface of a plate at various values of the Mach number. The results of calculations are compared with experimental data.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 23, No. 1, pp. 112–120, July, 1972.     

Numerical simulation of a two-dimensional turbulent wall jet in an external stream

Turbulent wall jets possess a region with negative production of turbulent kinetic energy between the points of maximum velocity and vanishing shear stress. This characteristic feature cannot be shown with many turbulence models. The use of an extended expression for the primary turbulent shear stress together with a k–? or an algebraic Reynolds stress model results in a model which can show this physical property. Computed results obtained with this concept are compared with measurements and results obtained with the standard k–? model and a full Reynolds stress closure. It is shown that the computed results with the present and the Reynolds stress model are of similar quality. However, the Reynolds stress solution is more costly in computing time.     

Optimization of indoor wireless communication network layouts

Radio Frequency Data Communications (RFDC)technology is rapidly becoming a critical component of many traditional industrial engineering functions including materials tracking, inventory control, warehousing, order processing, shipping and database management. As a means of moving information, RFDC has many attractive features, such as speed, accuracy, reliability, convenience and low operating costs. When implementing RFDC systems a major problem is to quickly and efficiently determine the locations where transceivers should be placed so that effective radio communication can take place. The research described in this paper addresses this issue by developing a computerized layout simulation system that incorporates heuristic optimization methods to solve the placement problem. The effectiveness of this unique automated layout methodology is demonstrated by comparing it with the current method of utilizing manual site surveys, as well as with other placement methods. The methodology and solutions are validated by field-testing at actual facilities.     

Feasibility of retroreflective transdermal optical wireless communication

There is an increasing demand for transdermal high-data-rate communication for use with in-body devices, such as pacemakers, smart prostheses, neural signals processors at the brain interface, and cameras acting as artificial eyes as well as for collecting signals generated within the human body. Prominent requirements of these communication systems include (1) wireless modality, (2) noise immunity and (3) ultra-low-power consumption for the in-body device. Today, the common wireless methods for transdermal communication are based on communication at radio frequencies, electrical induction, or acoustic waves. In this paper, we will explore another alternative to these methods--optical wireless communication (OWC)--for which modulated light carries the information. The main advantages of OWC in transdermal communication, by comparison to the other methods, are the high data rates and immunity to external interference availed, which combine to make it a promising technology for next-generation systems. In this paper, we present a mathematical model and experimental results of measurements from direct link and retroreflection link configurations with Gallus gallus domesticus derma as the transdermal channel. The main conclusion from this work is that an OWC link is an attractive communication solution in medical applications. For a modulating retroreflective link to become a competitive solution in comparison with a direct link, low-energy-consumption modulating retroreflectors should be developed.     

Influence of turbulent pr number on friction and heat transfer at a plate immersed in a turbulent gas stream

A solution is offered to the problem of determining the friction and heat transfer coefficients for a plate immersed in a turbulent gas stream, using the approximate dependence of heat content on velocity given in reference [1]. The influence of Pr_T on friction and heat transfer is evaluated.     

Investigation of gasdynamics of a vapor stream in heat pipes under turbulent conditions

Results are presented of an experimental investigation of the gasdynamics of a turbulent vapor stream in heat pipes, during simultaneous operation of the evaporation section, the adiabatic section, and the condensation section.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 34, No. 2, pp. 197–201, February, 1978.     

大气光通信中Turbo码的最大后验概率译码

为了精确实现对空间物体的测量,提出了利用线激光、单CCD相机、小孔成像与激光面约束模型的激光线测量法。引进三维信息已知的标准阶梯块作为激光面约束的标定块;由计算机控制摄像头对实物连续拍摄和实时处理,提取激光线上的像素坐标;利用建立的模型将二维坐标转换成三维坐标,再以点云的形式重构出物体,实现三维自动测量。实践中检测系统测量精度可达到0.05mm。