We propose Concatenated Location Management (CLM), utilizing tendency for mobile terminals (MTs) to move as a group. When many MTs are on the same train, for example, they move together and share the same mobility characteristics. Therefore, we propose to concatenate the MTs and link them to the train for more efficient location management. CLM can reduce the number of location management signals because the train sends only one location registration signal on behalf of all of the individual MTs when a location registration area boundary is crossed. We discuss the key functions for CLM including location registration, paging, and location register configuration.

In conventional Web Geographic Information System (GIS), there are serious drawbacks of high waiting time and low accessibility because the subsequent query has to wait until all the spatial data has been completely transmitted. In addressing these problems, this paper proposes a progressive transmission method which can reduce waiting time and increase accessibility. The proposed method has the following steps. First, significant vertices of geographic objects are selected into based on an algorithm, Priority_Order_Estimation (POE). Second, the selected vertices are inserted the data structure, Priority_Order_Queue (POQ). This allows a client to view, to request and occasionally to reject spatial data, rather than waiting for the whole map to arrive. Third, the transmission steps are processed progressively, where significant vertices of POQ are sent from server to client one by one. In the final step, if necessary, the entire spatial data set of SENDOBJSP, which is a transmission structure, is transmitted so that the original map is accurately displayed. The performance of the system proposed here has been evaluated according to the factors such as system response time and client storage space. For the comparisons, the total transmission method, layer transmission method and the proposed four-step transmission method were used. Compared with the conventional Web-based GIS, the system response time is twenty-two percent shorter and client storage space is reduced by about twenty-one percent. As a result, performance improvement, fast response time and less client storage usage, is achieved. Therefore, the proposed method can make a significant contribution in support of Web-based Vector GIS applications such as Environmental Management, Map On Demand Service and Assessment and Planning System.

In this paper, we propose an efficient requantization method for INTRA-frames in MPEG-1/MPEG-4 transcoding. The quantizer for an MPEG-1 INTRA block usually uses a quantization weighting matrix, while the quantizer for an MPEG-4 simple profile does not. As a result, the quantization step sizes of the two quantizers may not be the same even for the same quantization parameter. Due to this mismatch in the quantization step size, a transcoded MPEG-4 sequence can suffer from serious quality degradation and the number of bits produced by transcoding increases from the original MPEG-1 video sequence. To solve these problems, an efficient method is proposed to identify a near-optimum reconstruction level in the transcoder. In addition, a Laplacian-model based PDF (probability distribution function) estimation for the original DCT coefficients from an input MPEG-1 bitstream is presented, which is required for the proposed requantization. Experimental results show that the proposed method provides a 0.3-0.7 dB improvement in the PSNR over the conventional method, even at a reduced bit-rate of 3-7%.

A performance comparison is developed between a chaotic communication system and a spread spectrum system with similar features in terms of bandwidth and transceiver structure but based on more conventional Gold sequences. Comparison is made in the presence of noise and multipath contributions which degrade the channel quality. It is shown that, because of its more favourable correlation properties, the chaotic scheme exhibits lower error rates, at a parity of the bandwidth expansion factor. The same favourable correlation properties are also used to explain and show, through a numerical example, the benefits of chaotic segments in a multi-user environment.

We present a method to track and recognize shape-changing hand gestures simultaneously. The switching linear model using active contour model well corresponds to temporal shapes and motions of hands. However, inference in the switching linear model is computationally intractable, and therefore the learning process cannot be performed via the exact EM (Expectation Maximization) algorithm. Thus, we present an approximate EM algorithm using a collapsing method in which some Gaussians are merged into a single Gaussian. Tracking is performed through the forward algorithm based on Kalman filtering and the collapsing method. We also present a regularized smoothing, which plays a role of reducing jump changes between the training sequences of shape vectors representing complex-variable hand shapes. The recognition process is performed by the selection of a model with the maximum likelihood from some trained models while tracking is being performed. Experiments for several shape-changing hand gestures are demonstrated.

Network-oriented car navigation systems (off-board navigation systems) have become a hot topic cause of the expanding car navigation and active wireless communication markets. This paper examines the map downloading architecture, which realizes practical off-board navigation systems. We focus on practical technologies for present low speed wireless communication networks, such as with a 9.6 kbps transfer speed. We propose a new off-board navigation architecture, which combines a cost-effective map downloading system and a guide information downloading system. The proposed architecture can reduce the download data size to within about 50-100 kbytes for destination setting and route guidance. It has about a 1-2 minutes response time and about a 30-60 yen communication cost for a PDC (Personal Digital Cellular) wireless communication network in Japan. We consider this communication cost has a potential for a commercial off-board navigation system.

The transient phenomenon of electromagnetic waves caused by a time dependent resistive screen in a waveguide is treated by using Wiener-Hopf technique. A boundary-value problem is formulated to describe the phenomenon, in which the resistivity of screen varies from infinite to zero in dependence on time. Application of the Fourier transformation with respect to time derives a Wiener-Hopf equation, which is solved by a commonly known decomposition procedure. The transient field is derived from the solution of the equation in terms of the Fourier inverse transform. By using the incomplete Lipschitz-Hankel integral for the computation of the field, numerical examples are given and the transient phenomenon is discussed.

In this paper, a method is proposed to construct an n-out-of-n visual secret sharing scheme for gray-scale images, for short an (n,n)-VSS-GS scheme, which is optimal in the sense of contrast and pixel expansion, i.e., resolution. It is shown that any (n,n)-VSS-GS scheme can be constructed based on the so-called polynomial representation of basis matrices treated in [15],[16]. Furthermore, it is proved that such construction can attain the optimal (n,n)-VSS-GS scheme.

As technology moves to 600-1000 Gb/sq-in areal densities and deep sub-10 nm head-disk spacing, it is of crucial importance to prevent both the conventionally defined thermal decay and the tribologically induced decay of recorded magnetic signal. This paper reports a novel method for recording and visualizing the signature of the potential tribological decay. The details of the methodology, its working principles, and typical results obtained are presented in this work. The method is based on the introduction of a type of visualizing disks which use a layer of magneto-optical material with low Curie temperature to replace the magnetic layer used in the conventional magnetic media. The method and corresponding setup were used successfully in the visualization of potential decay caused by slider-particle-disk contact, slider-disk contact during track seeking operations, and slider-disk impact during loading and unloading operations.

A practical EB-testing-pad method, that enables higher observability of multilevel wiring LSIs without any increase of chip size, has been evaluated by using actual 0.25-µm SIMOX/CMOS devices. First, an 80k-gate logic LSI with testing pads was developed, and it was proved that observability improves from 17% to 87%. Next, two kinds of gate-chain TEGs (test element groups), with and without testing pads was developed to investigate the influence of testing pads on gate delay. It was found that the circuit delay increase due to the pads is very small, less than 2.7%. It was also found that capacitances from neighboring wires will increase only by at most 3% due to the testing pads. Thus, the testing pad method has been proved to be extremely effective in improving observability without any overhead in design.

To obtain a high throughput for transmission control protocol (TCP) connections over the wireless links, we previously proposed a novel transmission power control method for code division multiple access (CDMA) packet communication systems. By using this transmission power control method, we developed a transmission power control method and a packet multiplexing method to transmit constant bit rate (CBR) and TCP packets over CDMA wireless systems. Our methods can guarantee the quality of service (QoS) for CBR connections and utilize bandwidth effectively without modifying the TCP protocol or using slot assignments. Evaluation of our methods by computer simulation showed that the proposed methods provide a near-maximum throughput and guarantee the packet loss ratio of CBR connections regardless of the number of connections.

An information retrieval model that intends to conceptually deal with the documents in the Internet is proposed. The first half of this model is a stage to select the documents, which may meet the user's long-term interests, by employing a filtering or retrieval system. The latter half is a stage for linear document arrangement and for adjacent cluster based browsing. For the document collection filtered out, similarity matrices are computed and then the documents are arranged such that the highly similar ones are adjacently placed. By this treatment the documents are considered to form the clusters, some of which are adjacently placed when they include similar documents. A user can satisfy her/his needs by first browsing in the clusters containing documents highly similar to a query, and next by extending the browsing process into the clusters adjacent to the ones just examined. In the adjacent clusters the documents having no keywords common to but conceptually related to the query can be found. Computational and statistical evaluations were done on two standard test collections. A virtual space navigator is also designed by using JAVA to assist a user in the browsing task.

Emerging requirement for higher rate data services and better spectrum efficiency is the main driving force identified for the third generation mobile radio systems. Moreover, it needs the capability of providing predictable qualities of service (QoS) for different applications. To maintain different QoS requirements, mechanisms such as call admission control (CAC) and load control, etc. are needed to achieve the required services. In this paper, we propose a CAC algorithm based on channel assignment in a multi-chip rate direct-sequence CDMA (MCR-DS-CDMA) cellular system supporting multi-rate services. Five multi-MBC (mapping of information bit rates to chip rates) channel assignment schemes and corresponding channel selection rules are proposed herein. Computer simulation, where multimedia applications are considered, is used to evaluate the system performance (e.g., blocking probability and system capacity) with different channel assignment schemes. Numerical results demonstrate that scheme 5 (i.e., Minimum-influence scheme) performs better because it provides the highest system capacity and least blocking probability.

The effect of a nonmagnetic hcp-underlayer on the epitaxial growth of CoCr19Pt10 magnetic layers on substrates of Al2O3(0001) single-crystal has been investigated. Thin films of (0001)-oriented single-crystal CoCr19Pt10 were obtained by employing non-magnetic underlayers of CoCr25Ru25 and CoCr25Ru25/Ti, while thin films of polycrystalline CoCr19Pt10 were grown after the deposition of underlayers of TiCr10 and CoCr40. The growth of thin film CoCr19Pt10 on a Ti(0001) underlayer was interpreted as quasi-hetero-epitaxial where the continuity of the lattice across the interface is disturbed while the overall crystallographic relationship between the two layers is maintained. A thin film of epitaxially grown CoCr19Pt10 has a compositional variation of a few percent across the film plane in terms of elements that forms the alloy.

Algorithms are presented for the four elementary arithmetic operations, to perform reliable floating-point arithmetic operations. These arithmetic operations can be achieved by applying residue techniques to the weighted number systems and performed with no accuracy lost in the process of the computing. The arithmetic operations presented can be used as elementary tools (on many existing architectures) to ensure the reliability of numerical computations. Simulation results especially for the solutions of ill-conditioned problems are given with emphasis on the practical usability of the tools.

This paper proposes an idea for modeling aggregated TCP/IP traffic arriving at a bottleneck link by focusing on its scaling behavior. Here, the aggregated TCP/IP traffic means the IP packet traffic from many TCP connections sharing the bottleneck link. The model is constructed based on the outcomes of our previous works investigating how the TCP/IP networking mechanism affects the self-similar scaling behavior of the aggregated TCP/IP traffic in a LAN/WAN environment. The proposed traffic model has been examined from the perspective of application to network performance estimation. The examinations have shown that it models the scaling behavior and queueing behavior of actual traffic, though it neglects the interaction among TCP connections that compete with each other for the single bottleneck link bandwidth.

This paper assesses the performance of the handoff algorithm based on distance and RSSI measurements in a multi-cellular environment by computer simulation. The algorithm performs a handoff if handoff initiation conditions, handoff possible conditions, and handoff selective conditions are met. The performance criteria are based on the average number of handoffs, the crossover points and the average number of outages. Numerical results are presented to demonstrate the feasibility of the algorithm. The performance of the distance-assisted handoff algorithm is compared with that of a conventional algorithm that utilizes signal strength alone. Overall, the distance-assisted algorithm exhibits higher performance in average number of handoffs and the crossover points, yet exhibits a higher number of outages on average than the conventional algorithm.

Carrying IP traffic over connection-oriented networks requires the use of bandwidth on demand schemes at gateways or network interfaces. A new virtual queue occupancy, which is more accurate than the classical one, is being proposed for IP/SONET bandwidth on demand. Based on the virtual queue occupancy, two enhanced periodic approaches for lossless services, LAVQ and LAVQL, are simulated and evaluated. Simulations show that LAVQ outperforms its counterpart LAQ in terms of bandwidth utilization. By curbing the queue occupancy fluctuation, LAVQL further promotes bandwidth utilization and conceals the influence of the system latency on delay jitter as well.

A new blind restoration method applying Real-coded genetic algorithm (RcGA) will be proposed, and this method will be proven valid for the blurred image restoration with unidentified degradation in the experiments. In this restoration method, the degraded and blurred image is going to get restricted to the images possible to be expressed in the point spread function (PSF), then the restoration filter for this degraded image, which is also the 2-dimentional inverse filter, will be searched among several points applying RcGA. The method will enable to seek efficiently among vast solution space consists of numeral coefficient filters. And perceiving the essential features of the spectrum in the frequency space, an evaluation function will be proposed. Also, it will be proposed to apply the Rolling-ball transform succeeding an appropriate Gaussian degrade function against the dual degraded image with blur convoluting impulse noise. By above stated features of this restoration method, it will enable to restore the degraded image closer to the original within a practical processing time. Computer simulations verify this method for image restoration problem when the factors causing image distortions are not identified.

Vector quantization (VQ) is an attractive image compression technique. VQ utilizes the high correlation between neighboring pixels in a block, but disregards the high correlation between the adjacent blocks. Unlike VQ, side-match VQ (SMVQ) exploits codeword information of two encoded adjacent blocks, the upper and left blocks, to encode the current input vector. However, SMVQ is a fixed bit rate compression technique and doesn't make full use of the edge characteristics to predict the input vector. Classified side-match vector quantization (CSMVQ) is an effective image compression technique with low bit rate and relatively high reconstruction quality. It exploits a block classifier to decide which class the input vector belongs to using the variances of neighboring blocks' codewords. As an alternative, this paper proposes three algorithms using gradient values of neighboring blocks' codewords to predict the input block. The first one employs a basic gradient-based classifier that is similar to CSMVQ. To achieve lower bit rates, the second one exploits a refined two-level classifier structure. To reduce the encoding time further, the last one employs a more efficient classifier, in which adaptive class codebooks are defined within a gradient-ordered master codebook according to various prediction results. Experimental results prove the effectiveness of the proposed algorithms.