bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method for signal transmission and processing in vehicles
Authors: He Aiguo , Kawamata Akira 
Published: July 2007

AbstractThis paper discusses the method for controls, signal transmission and processing of the proposed integrated electronic system for vehicles. It is shown that the data transmission within a vehicle can be simplified by utilizing the properties of the signals in vehicles, and a memory structure is presented for the communication and control units of the system. The software is also discussed, indicating that the errors during transmission can be corrected automatically. Finally, the message collision rate during transmission is shown to be proportional to the message occurrence rate in the system, and the proportional constant is determined. It is shown also that the data transmission delay can be ignored for the low‐speed controls; and, however, the data used for the high‐speed controls should be transmitted without the transmission ring.
Centrality functions defined by minimum vertex cuts separating two vertices in a network
Authors: Takeuchi Masashi , Morishima Naohiko 
Published: July 2007

AbstractThe discussion of the centrality of each vertex in a network which is an abstract of communication and transportation, etc., networks is one of interesting topics in network theory, and various centrality functions expressing the centrality of vertices in networks have been proposed regarding this problem. This paper defines a centrality function, using minimum capacity of vertex cuts separating two vertices, as a measure of expressing the relation between two vertices in a network, and describes its fundamental properties. Although this minimum capacity of vertex cuts separating two vertices has not been investigated in the existing literature for centrality functions, it is considered to be one of fundamental quantities expressing the relation between two vertices in a network in which vertices have capacities. Also, defining the centrality function using this quantity seems to be significant.
Decoupling of multiinput‐output system containing two kinds of independent variables
Authors: Kawakami Atsushi 
Published: July 2007

AbstractDecoupling of a system is a procedure to establish a one‐to‐one correspondence between the input and the output of the system, by giving a state or output feedback to the system. This paper proposes a decoupling method for the general multiinput‐output system containing two kinds of independent variables. An analysis is presented for the realization dimension. The possibility of reducing the dynamical dimension of the dynamical feedback, the dynamical feedforward given to decouple is also discussed. Then to stabilize the decoupled two‐variable system, a method is considered in which the poles of the elements of the transfer function matrix are assigned to the desired locations.
Antenna‐beam allocation for a satellite‐fed millimeter‐wave personal communication system
Authors: Shimada Masaaki , Yoshimoto Shigetoshi , Suzuki Yoshiaki , Iida Takashi 
Published: July 2007

AbstractThe satellite‐fed millimeter‐wave personal communication system that is described requires a satellite with a multi‐beam antenna in order to guarantee the required link availability in point‐to‐point communications between numerous widely distributed small Earth stations. The usual method of antenna beam allocation requires high beam power in the downlink, giving rise to realizability problems due to limitations on the output power of the millimeter‐wave transmitter. This paper proposes an approach to optimizing the allocation of downlink antenna beams in which the beams are assigned to service areas that are chosen with reference to population distribution, rainfall attenuation in the millimeter‐wave region, and constraints on beam power. A computer simulation based on nationwide rainfall attenuation and population distribution data indicates that the proposed approach is more effective than with the usual beam allocation method. The equipment configuration of the satellite is described.
Analysis of balanced stripline branch‐line 3‐dB hybrid circuit based on planar circuit model
Authors: Anada Tetsuo , Jui‐pang Hsu 
Published: July 2007

AbstractThe stripline branch‐line 3‐dB hybrid is an important circuit used frequently at microwave and millimeter‐wave frequency ranges. At high frequencies where the dimensions of the discontinuous sections with respect to the wavelength are no longer negligible, the electromagnetic disturbance needs to be included accurately in the analysis and design. In this paper, an analysis of a balanced stripline branch‐line 3‐dB hybrid is described in which such electromagnetic disturbances are taken into consideration. The balanced stripline is approximated by a planar transmission line so that the entire hybrid circuit is replaced with a planar circuit to which the planar circuit theory is applied. The paper develops a systematic analysis method. Further, based on the analysis method described here, frequency characteristics of the basic hybrid circuit are derived. The frequency range at which the characteristics start degrading, and the causes, are described.
A multiple address data communication system via satellite link
Authors: Shiozaki Akira 
Published: July 2007

AbstractOne of the features of satellite communications is broadcasting ability (multiple address communication). Since a satellite has lengthy transmission delay, transmission errors at each link accumulate and the number of retransmissions increases, resulting in decrease in throughput efficiency if a one‐to‐one transmission control procedure (such as HDLC) is applied to a multiple address communication. This research proposes a multiple address communication system via a satellite link. In this system, information sequence is divided into N blocks based on the Chinese Remainder Theorem and the N blocks are sent with the SREJ (selective reject) procedure. At a receiving station the original information sequence can be restored with at least K(N) received frames. Therefore, the number of frames re‐sent from a transmitting station decreases and a decrease in throughput efficiency is prevented. The transmission characteristics of the proposed system are examined under the assumption that an ideal SREJ procedure is used. As a result, it is revealed that the proposed multiple address communication system can achieve higher throughput efficiency than the iterations of individual one‐to‐one communication.
A unified coding method of dithered image and text data using micropatterns
Authors: Nakamura Yasuhiro , Matsui Kineo 
Published: July 2007

AbstractThis paper introduces a unified coding algorithm for dithered image and text data. When a gray scale image is represented by binary pseudo‐half‐tone, various binary patterns representing the same gray scale are generated based on the degree of freedom in the dither matrix. Then one of the binary patterns is selected to represent the corresponding text data. The proposed algorithm permits approximately 70k bytes of text data to be embedded into a 256 × 256‐pixel image. It enables the transmission and handling of the mixture of image and text data without processing the two types of data separately.
Three‐dimensional analysis of patch antenna by bergeron's method
Authors: Kashiwa Tatsuya , Yoshida Norinobu , Fukai Ichiro , Koike Shoichi 
Published: July 2007

AbstractRecently, extensive efforts have been expended in research and development of patch antennas which are small in size, lightweight and not very thick. In these antennas, the effect of the near field on the far field characteristics cannot be ignored. The former is affected in turn not only by the antenna element but also by the shape of the structure on which the antenna is installed. This near field has a complex field distribution which is dependent on the three‐dimensional structure and the medium conditions of the system. A systematic analysis in which the three‐dimensional structure and the medium conditions of the system are given rigorous consideration is indispensable. In this paper, a rectangular patch which is a basic form of the patch antenna is analyzed by the Bergeron method in terms of the three‐dimensional time response of the near field. Based on the aperture distribution of the electric field thus obtained, the far field is computed by Fourier transform. A method is proposed for efficiently deriving the far field in the Bergeron method. By comparison with analytical solutions, the validity of the fundamental treatment is verified. Further, by taking advantage of vector analysis, the electric field near the patch is expressed in a vector form for both the linear and circular polarizations. The spatial and temporal evolution of the field and the change from the near field to the far field are exhibited. Also, by means of the representation of the Poynting vector, the energy flow important for understanding the radiation characteristics of the antenna is depicted. The fundamental characteristics of the patch system are thus obtained.
Simulation of an echo distortion automatic canceller in an fm broadcasting receiver
Authors: Kondo Shoji , Date Hikaru 
Published: July 2007

AbstractIn FM broadcast reception, the echo distortion due to the interference between the direct wave and reflected waves produced in the propagation path is one of the factors in deterioration of sound quality. Results of simulation based on the principle reported previously are presented on the system that automatically cancels this distortion within a receiver. The simulation is conducted under the assumption that the cancellation process is carried out by a totally digital operation after the IF signal is A‐D converted. The echo distortion can be cancelled if the tap coefficients of the canceller containing a tapped delay line with a set of corresponding discrete tap delay times is controlled based on the observation result of the amplitude frequency characteristics of the input signal. It is necessary to set several tap coefficients even for a reflected wave with an arbitrary delay time. The results of simulation agreed with the theoretical predictions. As an example, the distortion factor of 37.2 dB of the demodulated output signal for an echo with the reflection coefficient of 0.5 and delay time of 8 μs even with the infinitely large input CN ratio of the receiver was reduced to 67.9 dB by the action of the canceller so that an SN ratio satisfying the broadcast standard is obtained.
An evaluation method for the reflection coefficient of building walls
Authors: Satoh Akio , Ogawa Eiichi 
Published: July 2007

AbstractIt is necessary to evaluate the effect of building wall reflection because the reflected waves interfere with radio communication systems in a built‐up area. As there are many kinds of unevenness on a building wall, the reflected wave consists of several waves that are reflected on different surfaces. The reflected wave has a strong frequency dependence. This indicates that the measurement of a single frequency is insufficient. Thus, an evaluation based on the measurement results at a wide frequency band is necessary.First, this paper shows that the reflection coefficient of building walls has a remarkable frequency dependence by the measurement results on a 26‐GHz band. The relationship between the frequency dependence and wall surface unevenness is also clarified. Second, an evaluating method using a probability distribution, which is effective for varying the reflection coefficient in the band, is proposed. Third, the reflection coefficient distribution considering various kinds of walls is approximated by a Rayleigh distribution. Finally, the probability distribution of a two‐time reflection coefficient is also derived and the correspondence of distributions between estimated and measured is discussed.
Improvements in TDMA circuit switching services on a tree‐shaped broadband network
Authors: Saito Yoshihiro , Haruyama Hideaki , Ozawa Kazuyoshi , Tanaka Masashi 
Published: July 2007

AbstractThis paper attempts to realize the TDMA circuit switching service on the broadband tree‐shaped network applying the two‐way coaxial CATV techniques. The improvement of the time‐slotted bus system with controller window proposed previously by the authors is discussed.To make this system practical, such problems as simplification of terminal device and expansion of service scale must be solved. For this purpose, the “center measurement method” and the “variable width control window method” are developed anew. The former is a system which measures such parameters as the round‐trip transmission delay at the central control device and notifies the terminal of the result.By improving the down‐link transmission quality of the control window, which is important from the viewpoint of the stable operation of the whole system and by reducing the high‐speed operation functions, the terminal device is simplified. The latter is to adjust the control window width according to the traffic. By this scheme, the number of contained time‐slots, i.e., the number of serviceable subscribers, can be increased without reducing the wide service area of the broadband tree‐shaped network. A prototype system was constructed based on those two system improvements, and an experimental evaluation was attempted on the experimental two‐way CATV system with a total length of 7.9 km. As a result, it was verified that the foregoing improvements are useful and matched to each other.
Phase controlling for improving the gain or providing the low cross‐polarization level in circularly polarized phased array antennas
Authors: Chiba Isamu , Ohtsuka Masataka , Matsumoto Souichi , Katagi Takashi 
Published: July 2007

AbstractWhen a circularly polarized phased array is used for communication, it is required to maintain a high gain and suppress the cross polarization over the beam scanning region and over the frequency region. However, in the traditional phase‐setting method in which only the feed line length and the array factor are taken into consideration, the desired radiation characteristics cannot be obtained because the elemental electric field in the array environment is fluctuated by the effect of the mutual coupling between the elements and the scattered wave from the structures.In this paper, a method is presented for improving the gain and suppressing the cross‐polarization level by controlling the excitation phase with the phase shifters inherent to the phased array under these complex electromagnetic environments. The main idea of the present method is in the measurement of the correct and cross‐polarization components for each element antenna and in the derivation of the optimum excitation phases based on the minimization algorithm of the output power. An experiment is carried out in which the proposed method is compared with the phase‐setting method where only the feed line length and the array factor are taken into account. Thus, the effectiveness of the proposed method is demonstrated.
An optimal scope‐pattern decision method for OSI management operations
Authors: Nagai Yasuhiko , Sugauchi Kiminori , Suzuki Michio 
Published: July 2007

AbstractPresently, integrated network management systems are being developed based on the open systems interconnection (OSI) management standards to manage information networks under the multivendor environment in an integrated manner. In this paper, an optimal scope‐patterns decision method for efficient OSI management operation is proposed. The scope patterns are common management information service (CMIS) operational range specifications based on the containment relationship between managed objects. The motivation for this study is to improve human interfaces for network management systems by providing a translating function for operator‐specified operational ranges based on various kinds of relationships into CMIS scope patterns. The proposed method provides the ability to translate automatically operator‐specified operational ranges based on any kind of relationship into possible CMIS scope‐pattern candidates and the ability to define optimal scope patterns for minimizing invoked operations by solving an integer programming problem using a fast computing approximate algorithm. Thus, network management operators can achieve user‐friendly human‐machine interaction and efficient management operation.
Elimination of adjacent channel interference Via nonlinear filters
Authors: Nagayasu Takayuki , Sampei Seiichi 
Published: July 2007

AbstractIn recent years, eliminating adjacent channel interference (ACI) for effective utilization of frequency resources has been considered important in digital radio communications. As an effective method for eliminating interference, adaptive equalizers have been utilized and limitations associated with their linear form processing have also been clarified.In this study, as equalizers showing better interfering wave‐eliminating characteristics of adaptive linear equalizers (ALEs), an adaptive nonlinear equalizer (ANLE) containing the conventional nonlinear ALE and a nonlinear canceller, which eliminates ACI by nonlinear processing, in its body are proposed and their efficiencies are verified by computer simulations.First, the optimal number of taps of the proposed ANLE was determined by computer simulations and the characteristics obtained with an optimal number of taps have been compared with those of the conventional method. The results showed that the proposed ANLE can effectively eliminate the interfering wave component whose spectrum has become overlapped with a desired wave and thus gives better interfering wave‐eliminating characteristics than the ALE and the nonlinear canceller.
transmission and radiation properties of a surface wave transmission line with a bend
Authors: Nakamura Takashi , Kamiya Shinji , Yokokawa Senji 
Published: July 2007

AbstractAs a cause of generation of unwanted electromagnetic radiation, the bend of a surface wave transmission line is investigated. The transmission and radiation characteristics at the bend are studied analytically and experimentally. First, by applying the traveling wave mode method, it is shown that the transmission characteristics of the surface wave transmission line can easily be obtained. The change of the equivalent voltage near the bend is observed.Next, the discontinuity of the traveling wave current is considered as a radiating source and the radiation field from the bend in a surface wave transmission line is derived by means of the principle of pattern multiplication. It is found that there exist an electric field component which strongly radiates into the traveling directions of the current in a bent transmission line and the component which radiates into the intermediate direction. It is found that the power is radiated strongly into the intermediate direction. Further, by experiments which agree well with the theoretical results, the validity of the method is presented.
SDH signal transfer method based on ATM techniques
Authors: Ueda Hiromi , Uematsu Hitoshi 
Published: July 2007

AbstractAsynchronous transfer mode (ATM) networks are nonhierarchical networks that can reduce network cost and simplify network operation, administration, maintenance, and provisioning. During the period in which ATM and existing synchronous digital hierarchy (SDH) networks coexist, it is necessary to convey SDH signals using ATM technologies. First, the SDH signal transport units, the VC or TU/AU level, are considered and the best choice is found to be TU/AU. Next, algorithms for handling lost and misdelivered cells using the sequence number SN and its protection SNP are presented. Finally, SDH signal phase information transport methods are discussed.
ATM switching system with bandwidth control function
Authors: Kozaki Takahiko , Takase Akihiko , Yanagi Jun'Ichirou , Tanabe Shiro , Gohara Shinobu 
Published: July 2007

AbstractIn the 21st century, 10∼30 Mbps video services will be the main traffic services of B‐ISDN. Therefore, bandwidth control is effective for dividing a 150‐Mbps line into the call bandwidths. A shared buffer‐type ATM switch with this function can be achieved by queueing call by call and by reading out cells from the queues according to the bandwidth control table sequence. When the traffic is random with utilization of 0.9, the switch with 128∼512 queues on the 4000‐cell shared buffer has sufficiently small cell loss characteristics.Multiqueueing technology is provided by embedded RAMs which point to the first addresses and last addresses of the queues. Queue length control, which limits each queue length, for multiqueueing is provided by the embedded RAMs. A one‐board switch with 128 queues on a 4000‐cell shared buffer is developed.
Network configurations for leased circuits in metropolitan areas
Authors: Hoshi Keiichi , Kawata Takao 
Published: July 2007

AbstractWith the rapidly increasing demand for leased service, an important issue in the future telecommunication network will be efficient utilization of leased circuits.This paper considers the network configuration for leased circuits in the metropolitan area, where the demand for such circuits is increasing. This paper also discusses the allocation of cross‐connect (XC) nodes in the construction of the network for low‐speed leased circuits and the segregation/sharing of public and leased circuits from the viewpoint of economy.First, the system configuration for the low‐speed leased circuits and the network topology for the efficient operation of the leased circuits are discussed. As a result, allocation schemes for XC nodes and schemes for fiber segregation and transmission capacity are proposed. Then the relation between the number of XC nodes and the network cost, as well as the relation between the transmission capacity and the network cost, are discussed from the viewpoints of the segregated and the shared configurations for the leased and public circuits. From this discussion, the optimal XC node allocation and the optimal transmission capacity are shown. Finally, a comprehensive assessment is described and the optimal area for each of the proposed network configurations is shown quantitatively for the case where the demand for the leased circuit or the equipment cost is varied.
Long‐span 2.5‐gbit/s cpfsk coherent optical transmission system employing high‐output power edfa boosters
Authors: Hayashi Yoshihiro , Ohkawa Norio , Yanai Daisuke , Ito Takeshi 
Published: July 2007

AbstractThis paper explains a system configuration for long‐span applications of repeaterless optical transmissions for their corresponding efficiency. From the results of a year‐long field test and in‐house experiments, the practicality of the CPFSK heterodyne delay demodulation method for 2.5 Gbit/s using a high‐output optical fiber amplifier has been evaluated.
A versatile two‐dimensional device simulation program and its application to NMOS
Authors: Ueda Jun , Namba Yoichi , Sakamoto Koichi , Miyoshi Tatsuro , Ushio Shintaro 
Published: July 2007

AbstractThe versatile algorithms of two‐dimensional device simulation programs are studied in detail. We have separated the device simulator which is independent of the device structure and the user's analysis purpose, and the preprocessor that specifically deals with user interface. Moreover, the algorithms of the device simulator become the discretization by information obtained at the nodes only, electrode current definition at the nodes of electrodes, initial guess using two‐dimensional numerical depletion approximation, and the iterative operation of the device simulation by step design. Using these algorithms we developed a two‐dimensional device simulator UNISAS, and confirmed the validity of the versatile algorithm using an example of NMOS. Step design is used for the analysis of the avalanche phenomenon of NMOS. Solving for the two carriers, we have explained easily the flow of electrons and holes in the avalanche breakdown phenomenon. Moreover, by changing only input data, we have easily analyzed the five‐gate NMOS.