bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calculation method of separation angles and interference between satellite and radio‐relay links in atmospheric refraction condition
Authors: Ooi Tetsuo , Saito Yoichi 
Published: July 2007

AbstractWhen the frequency sharing between the fixed satellite communication system and the radio relay system is realized, it is indispensable to evaluate the interference noise in the design of each channel. Especially, to treat the interference between the satellite station and the terrestrial radio‐relay station, it is necessary to find the separation angle between the radio‐relay antenna beam and the geostationary satellite orbit.This paper presents a method for evaluation of the separation angle with the atmospheric beam refraction. The beam refraction angle is given as an integration along the beam path of the infinitesimal rate of change of the elevation angle for the altitude. A simple approximate expression is derived for facilitating the derivation of the separation angle. By comparison with the rigorous theory, the approximation errors are shown to be small enough for all practical purposes. A computation method for the separation angle is described for a terrestrial radio‐relay station position and an antenna beam direction from the geostationary satellite orbit. As an application, an actual radio‐relay link is chosen for which the separation angle distribution and the interference noise distribution are derived. By means of the computational method presented in this paper, the interference noise from the satellite station to the terrestrial radio‐relay station is now evaluated rather easily.
An adaptive CSMA/CD system
Authors: Yasuda Chikara , Fujiwara Chikato , Okumoto Takaaki 
Published: July 2007

AbstractThis paper proposes a control method for the retransmission rate in the continuous‐time 1‐persistent CSMA/CD system with a finite number of stations so that the throughput is maximized. It is shown first that there exists an optimal load that maximizes the throughput. Assuming that the system always operates for the optimal load, the maximum throughput that can be achieved in the 1‐persistent CSMA/CD system is derived. Then an adaptive CSMA/CD system is proposed in which each station monitors the number of collisions and other parameters to estimate the present load and determines the retransmission rate so that the optimum load is realized.As a result of simulation, it is shown that the adaptive CSMA/CD system exhibits a considerably better performance than the Ether‐type CSMA/CD system employing the binary exponential back‐off algorithm based on the 1‐persistent scheme. It is shown that the proposed system can realize the throughput which is almost close to the forementioned maximum in the highly loaded condition.
UHF band spatial correlation characteristics of mobile base station antennas
Authors: Akeyama Akira , Sakagami Shuji , Aoyama Shigeru 
Published: July 2007

AbstractSpatial correlation characteristics of the base station antenna in a mobile propagation path have been studied in the past in the case where the antenna height is sufficiently greater than the average building height in the surrounding area. However, for effective use of frequencies, the base station antenna height may be reduced so that the radio zone can be made smaller. To this end, it is necessary to determine the method for computing the spatial correlation characeristics in the case where the base station antenna height is comparable to the average building height.In this paper, the arriving angle distribution of the multiple waves in an urban area is measured and the ration of the scattered wave level to the main arriving wave level is related to the antenna height and the antenna gain. Also, a method is proposed for deriving the spatial corrrelation coefficient by means of a and its usefulness is verified by measured results.
Transform image coding with edge compensation
Authors: Shimono Tetsuo , Kanda Yoshio , Kitajima Hideo , Ogawa Yoshihiko 
Published: July 2007

AbstractA method to prevent edge degradation caused by orthogonal transform image coding is proposed. The method contains three processes: 1) obtain a differential image between the original and low‐pass one; 2) extract significant pixels concerning the edge degradation; and 3) add these pixels to compensate for the edge degradation.Since an edge has a spatial length, five or more connected pixels whose value exceeds a threshold are selected in the differential image as significant error pixels. Furthermore, using human visual perception that is very sensitive to the existence of an edge but very loose in its exact value and its exact location, the additional information (overhead) for compensation is saved. The significant edge information is quantized three levels corresponding to positive error, negative error, and no error. Then edges are classified in four directions after slight geometric approximations. Four one‐dimensional images with three‐level value are assigned by Huffman code. Run‐length coding is used jointly for the zero error pixels. The additional information for the edge compensation requires a few bits, but the image is reconstructed very clearly.
A study of vertical space diversity for a land mobile radio
Authors: Ebine Yoshio , Takahashi Tatsumi , Yamada Yoshihide 
Published: July 2007

AbstractVertical space diversity used for reduction of deep fading in the mobile propagation path is effective for the base station and mobile station for the future land mobile communications for which the installation conditions become increasingly more severe due to the smallness of the area occupied by the antenna in this system. In this paper, the correlation coefficient of the vertical space diversity is studied theoretically and experimentally in the case where the antenna height changes from the mobile station to the base station. Further, from the comparison of the computed and measured data of the correlation coefficient, the spatial divergence of the multiple waves arriving at the antenna has been studied due to its importance in finding the diversity effect.The divergence of the multiple wave vs. the antenna height is estimated. As a result, the antenna spacing needed to obtain the diversity effect for an arbitrary antenna height is obtained easily. For instance, in the case where the antenna height is 156 m, the standard deviation of the divergence of the arriving wave is 0.2 deg. If the correlation coefficient is assumed to be less than 0.6, the required antenna spacing is about 30 wavelengths. For the antenna height of 1.5 m, the standard deviation of the divergence of the arriving wave is about 11 deg and the required antenna spacing is about 0.3 wavelengths.
Investigation of a compartment‐mounted diversity antenna for land mobile radios
Authors: Ebine Yoshio 
Published: July 2007

AbstractWhen constructing a compartment‐mounted diversity antenna for land mobile communication, it is important to provide an antenna branch with a small correlation factor and to improve the receiving level degradation due to the effect of the vehicle body. To solve these problems, a directivity diversity antenna is proposed which is in a hybrid circuit form with antennas placed near the front and rear windows of a passenger sedan with respect to the direction of motion. This antenna was studied theoretically and experimentally. If the antenna element has a beamwidth of 180° in the horizontal plane and a gain of 3 dBd, a receiving level almost identical to that of an omnidirectional 0‐dBdgain antenna in the horizontal plane installed outside the vehicle was attained in an urban area. The correlation coefficient was small between the terminals.
Correlation bandwidth in urban mobile radio paths—dependence of distance, base station antenna height and average building height
Authors: Sakagami Shuji , Akeyama Akira 
Published: July 2007

AbstractThis paper describes the measured results of the correlation bandwidth in urban radio paths and the relationship between the measured values of the correlation bandwidth and the propagation parameters useful for system design of digital mobile communications. The correlation bandwidth was derived from the measurement of the amplitude‐frequency characteristics in a bandwidth of 915 to 920 MHz. Within a distance of 0.5 to 3 km from the base station, it is found that the correlation bandwidth is about 80 to 360 kHz, if the base station antenna height is several tens to 100 m. It is found also that the correlation bandwidth: (1) decreases with the distance, (2) increases with the base station antenna height, and (3) decreases with the average building height.The relationship of the correlation bandwidth with the distance, base station antenna height, and the average building height (within a circle of a radius of 3 km centered at the base station) has been studied by multiple regression analysis. The distance dependence, base station antenna height dependence, and average building height dependence have been quantized and a prediction formula for the correlation bandwidth is obtained.
Structure packing of coded video signals for ATM networks
Authors: Wada Masahiro , Takishima Yasuhiro 
Published: July 2007

AbstractIn asynchronous transfer mode (ATM) networks, a cell loss may occur and cause burst errors or synchronization slips which damages the decoded picture. Therefore, some type of cell‐packing method is required which minimizes the picture deterioration.A structured packing for coded video signals is proposed which achieves a short packing delay and high transmission efficiency. The method is based on the structure of coded video signals and makes use of cell synchronization for coded data synchronization.The characteristics of the method have been analyzed by simulations using actual TV pictures and the effectiveness of the method has been shown. This method can be discussed from the viewpoint of the ATM adaptation layer.
Synchronous rectifier using bipolar transistor driven by current transformer
Authors: Sakai Eiji , Harada Koosuke 
Published: July 2007

AbstractIn the power supplies to obtain a low output voltage and a high current, it is difficult to obtain high efficiency due to the forward voltage of the diode for output rectification. A method has been reported for improving the efficiency of the power supply by using bipolar transistors (BJT) with a low saturation voltage as a rectifier so that the forward voltage is reduced. However, in general, a driving circuit for the BJT is required and the application of the latter to a power supply is not straightforward.This paper proposes a synchronous rectifier system which drives a BJT by a positive feedback by a current transformer. The operating principle of this circuit is described. The reset condition of the magnetization energy of the current transformer is clarified. The present method has a simple circuit configuration in which a part of the emitter current of the BJT is used as a base‐driving current by means of a current transformer. No special BJT driver circuit is needed. The present synchronous rectifier was installed in an actual power supply. It was confirmed that the efficiency is improved over the circuit using Schottky diodes.
Application of spread spectrum communication and its devices
Authors: Tsubouchi Kazuo 
Published: July 2007

AbstractThis paper first outlines the key devices needed in the correlation detection of the spread spectrum (SS) signal. Then the device for SS communication and a modem for SS communication developed by the authors are described. The authors also have developed a ZnO/ Si‐type SAW convolver which has a high efficiency and is suited to the portable SS communication modem. Employing this device for the correlation detection of the SS signal, an SS wireless modem is developed which operates completely asynchronously by the direct sequence (DS) mode. By an experiment using this modem and based on the domestic electromagnetic wave law, it is verified that the communication for the visible distance of 100 m is possible for the weak field regulation. A field test also is executed based on the SS communication frequency in the United States (FCC Part 15, 902‐928 MHz), and the propagation distance of 16 km is verified using the output of 1 W.
User programmability of communication network services with associative‐memory neural networks
Authors: Hattori Shimmi , Mizusawa Junichi , Murakami Koso 
Published: July 2007

AbstractIn the realization of various kinds of services by intelligent network (IN), the key issue is user program‐mability, where the user actually defines/executes the services on the communication network.This paper attempts to utilize the content search, generalization and robustness of the associative memory‐type neural network and presents a system where the user programmability is realized by example inputs without the programming. An evaluation by simulation is executed with the case of telephone delivery service as an example. It is shown as a result that the user programmability of the communication network service can be realized even for the user with a low skill level, allowing the fuzzy access with incomplete input information.
Are you being served…? An unobtrusive experiment of affective influences on helping in a department store
Authors: Forgas Joseph P. , Dunn Elizabeth , Granland Stacey 
Published: July 2007

AbstractBased on recent theories of affect and cognition, this unobtrusive field experiment predicted and found that induced positive mood improved real‐life customer service behaviors by less experienced sales staff, but had no effect on the behaviors of experienced long‐term staff in several department stores. Positive or negative mood was unobtrusively induced in sales staff in major department stores by a confederate. A second confederate, blind to the mood induction, then asked employees for help to locate a non‐existent item. The frequency and duration of helpful behaviors in response to the request was recorded. Consistent with Forgas' Affect Infusion Model (AIM), less experienced employees showed a significant mood‐congruent pattern in their responses helping more in a positive than in a negative mood. Long‐term employees who could rely on routine, direct access processing were not influenced by the mood induction. The implications of these findings for contemporary affect‐cognition theorizing and for everyday affective influences on interpersonal behaviors and customer service delivery are considered. Copyright © 2007 John Wiley & Sons, Ltd.
Emissions of greenhouse gases attributable to the activities of the land transport: modelling and analysis using I‐CIR stochastic diffusion—the case of Spain
Authors: Gutiérrez R. , Gutiérrez‐Sánchez R. , Nafidi A. 
Published: July 2007

AbstractIn this study, carried out on the basis of the conclusions and methodological recommendations of the Fourth Assessment Report (2007) of the International Panel on Climate Change (IPCC), we consider the emissions of greenhouse gases (GHG), and particularly those of CO2, attributable to the activities of land transport, for all sectors of the economy, as these constitute a significant proportion of total GHG emissions. In particular, the case of Spain is an example of a worrying situation in this respect, both in itself and in the context of the European Union. To analyse the evolution, in this case, of such emissions, to enable medium‐term forecasts to be made and to obtain a model that will enable us to analyse the effects of possible corrector mechanisms, we have statistically fitted a inverse Cox‐Ingersoll‐Ross (I‐CIR) type nonlinear stochastic diffusion process, on the basis of the real data measured for the period 1990–2004, during which the Kyoto protocol has been applicable. We have studied the evolution of the trend of these emissions using estimated trend functions, for which purpose probabilistic complements such as trend functions and stationary distribution are incorporated, and a statistical methodology (estimation and asymptotic inference) for this diffusion, these tools being necessary for the application of the analytical methodology proposed. Copyright © 2007 John Wiley & Sons, Ltd.
Seismic demands on secondary systems in base‐isolated nuclear power plants
Authors: Huang Yin‐Nan , Whittaker Andrew S. , Constantinou Michael C. , Malushte Sanjeev 
Published: July 2007

AbstractNumerical models of a sample nuclear power plant (NPP) reactor building, both conventionally constructed and equipped with seismic protective systems, are analysed for both safe shutdown and beyond‐design‐basis earthquake shaking at two coastal sites in the United States. Seismic demands on secondary systems are established for the conventional and seismically isolated NPPs. The reductions in secondary‐system acceleration and deformation demands afforded by the isolation systems are identified. Performance spaces are introduced as an alternate method for evaluating demands on secondary systems. The results show that isolation systems greatly reduce both the median and dispersion of seismic demands on secondary systems in NPPs. Copyright © 2007 John Wiley & Sons,
Ltd.
Reliability Analysis of Technical Systems/Structures by means of Polyhedral Approximation of the Safe/Unsafe Domain
Authors: Marti K. 
Published: July 2007

AbstractReliability analysis of technical structures and systems is based on an appropriate (limit) state function separating the safe and unsafe/states in the space of random parameters. Starting with the survival conditions, hence, the state equation and the condition for the admissibility of states, an optimizational representation of the state function can be given in terms of the minimum function of a certainminimization problem. Selecting a certain number of boundary points of the safe/unsafe domain, hence, on the limit state surface, the safe/unsafe domain is approximated by a convex polyhedron defined by the intersection of the half spaces in the parameter space generated by the tangent hyperplanes to the safe/unsafe domain at the selected boundary points on the limit state surface. The resulting approximative probability functions are then defined by means of probabilistic linear constraints in the parameter space, where, after an appropriate transformation, the probability distribution of the parameter vector can be assumed to be normal with zero mean vector and unit covariance matrix. Working with separate linear constraints, approximation formulas for the probability of survival of the structure are obtained immediately. More exact approximations are obtained by considering joint probability constraints, which, in a second approximation step, can be evaluated by using probability inequalities and/or discretization of the underlying probability distribution. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parameter Identification in One‐Dimensional Partial Differential Algebraic Equations
Authors: Schittkowski K. 
Published: July 2007

AbstractIn this paper we discuss a couple of situations, where algebraic equations are to be attached to a system of one‐dimensional partial differential equations. Besides of models leading directly to algebraic equations because of the underlying practical background, for example in case of stationary equations, there are many others where the specific mathematical structure requires a certain reformulation leading to time‐independent equations. To be able to apply our approach to a large class of real‐life problems, we have to take into account flux formulations, constraints, switching points, different integration areas with transition conditions, and coupled ordinary differential algebraic equations (DAEs), for example. The system of partial differential algebraic equations (PDAEs) is discretized by the method of lines leading to a large system of differential algebraic equations which can be solved by any available implicit integration method. Standard difference formulas are applied to discretize first and second partial derivatives, and upwind formulae are used for transport equations. Proceeding from given experimental data, i.e., observation times and measurements, the minimum least squares distance of measured data from a fitting criterion is computed, which depends on the solution of the system of PDAEs. Parameters to be identified can be part of the differential equations, initial, transition, or boundary conditions, coupled DAEs, constraints, fitting criterion, etc. Also the switching points can become optimization variables. The resulting least squares problem is solved by an adapted sequential quadratic programming (SQP) algorithm which retains typical features of a classical Gauss‐Newton method by retaining robustness and fast convergence speed of SQP methods. The mathematical structure of the identification problems is outlined in detail, and we present a number of case studies to illustrate the different model classes which can be treated by our approach. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pipe smoking and cancers of the upper digestive tract
Authors: Randi Giorgia , Scotti Lorenza , Bosetti Cristina , Talamini Renato , Negri Eva , Levi Fabio , Franceschi Silvia , La Vecchia Carlo 
Published: July 2007

AbstractPipe smoking has been related to the risk of cancers of the upper digestive and respiratory tract, but quantification of the risk for exclusive pipe smokers is still limited. To analyse the association between exclusive pipe smoking and cancers of the upper digestive tract, we used data from a series of case–control studies conducted in Italy and Switzerland between 1984 and 1999. After excluding cigarette and cigar smokers, 41 male oral and pharyngeal cancer cases, 52 male oesophageal cancer cases and 1,032 male controls were included in the present analysis. Odds ratios (OR) of cancers were estimated by the mean of unconditional multivariate logistic regression, including terms for age, study centre, education, body mass index, and alcohol drinking. Compared to never smokers, exclusive pipe smokers had an OR of 8.7 [95% confidence intervals (CI): 4.0–18.9] of all upper digestive tract cancers. The OR was 12.6 for oral and pharyngeal and 7.2 for oesophageal cancer. Pipe smokers who were also heavy alcohol drinkers had an OR of 38.8 (95% CI: 13.6–110.9) as compared to never smokers and light drinkers. Thus, pipe smoking and heavy alcohol drinking appears to interact at least on a multiplicative model. © 2007 Wiley‐Liss, Inc.
The antibody MAB8051 directed against osteoprotegerin detects carbonic anhydrase II: Implications for association studies with human cancers
Authors: Waterman Elizabeth A. , Cross Neil A. , Lippitt Jenifer M. , Cross Simon S. , Rehman Ishtiaq , Holen Ingunn , Hamdy Freddie C. , Eaton Colby L. 
Published: July 2007

AbstractA commonly used monoclonal antibody targeting osteoprotegerin (OPG), MAB8051, detects a truncated protein species in breast and prostate cancer cell lysates. OPG expression has been reported to contribute to cell survival of both of these cancers. We hypothesised that the truncated protein represented a unique tumour‐associated OPG isoform. However, here we show that the truncated protein identified by MAB8051 in cancer cell lines is carbonic anhydrase II (CA II), also implicated in tumour biology. We clearly demonstrate cross‐reactivity of this OPG antibody in western blots. OPG and CA II RNA‐interference studies confirmed the identity of the bands. We show almost identical staining patterns between MAB8051 and CA II immunohistochemistry of different human tissue types and human tumour types using serial sections. We conclude that care should be exercised using this antibody for immunohistochemistry studies, without additional in situ hybridisation, or parallel use of other OPG‐specific antibodies. © 2007 Wiley‐Liss, Inc.