The demand for multi-application smart card platform has been increasing in various business sectors recently. When it comes to the actual implementation of the platform, however, network-based dynamic downloading in a Card Issuer-Service Provider separated environment has not made much progress. This paper introduces the smart card information sharing platform that uses licensing/policy/profile management and PKI-based technologies to enable multiple CIs and multiple SPs to reflect their own business policy flexibly via network. It makes the paradigm shift from card-oriented scheme to service-oriented scheme. By through world's first implementation of the scheme and some experiments including deployment, we confirmed that this technology is well-accepted and applicable to various business sectors and it can be of practical use.

Recently, Kuwakado and Tanaka proposed a transitive signature scheme for directed trees. In this letter, we show that Kuwakado-Tanaka scheme is insecure against a forgery attack, in which an attacker is able to forge edge signatures by composing edge signatures provided by a signer.

The paper presents a novel stroke decomposition approach based on a directional filtering technique for recognizing Chinese characters. The proposed filtering technique uses a set of the second-order Gaussian derivative (SOGD) filters to decompose a character into a number of stroke segments. Moreover, a new Gaussian function is proposed to overcome the general limitation in extracting stroke segments along some fixed and given orientations. The Gaussian function is designed to model the relationship between the orientation and power response of the stroke segment in the filter output. Then, an optimal orientation of the stroke segment can be estimated by finding the maximal power response of the stroke segment. Finally, the effects of decomposition process are analyzed using some simple structural and statistical features extracted from the stroke segments. Experimental results indicate that the proposed SOGD filtering-based approach is very efficient to decompose noisy and degraded character images into a number of stroke segments along an arbitrary orientation. Furthermore, the recognition performance from the application of decomposition process can be improved about 17.31% in test character set.

In this letter, the concept of cross-entropy is introduced for unsupervised polarimetric synthetic aperture radar (SAR) image classification. The difference between two scatterers is decomposed into three parts, i.e., the difference of average scattering characteristic, the difference of scattering randomness and the difference of scattering matrix span. All these three parts are expressed in cross-entropy formats. The minimum cross-entropy principle is adopted to make classification decision. It works well in unsupervised terrain classification with a NASA/JPL AIRSAR image.

In order to benefit from the advantages of soft handoff (SHO), it is important that the SHO parameters (the SHO thresholds; T_ADD and T_DROP are well assigned. T_ADD is the threshold used for triggering a pilot with high strength to be added to the Active Set (AS) list. The AS means the pilots associated with the forward traffic channels assigned to mobile station. In contrast, T_DROP is the threshold used for triggering a pilot with low strength to be dropped from the AS list. This paper analyzes the effects of varying SHO thresholds in a cellular code division multiple access (CDMA) system on the blocking probability based on traffic load and geometrical distances in hexagonal layout of base stations (BSs). In addition, the previously proposed traffic load equation is applied to the proposed SHO model for balancing the numbers of new and handoff calls on the forward link capacity in case of uniform traffic load. The results show that the blocking probability is more sensitive to T_DROP than to T_ADD variations.

We investigated the accuracy of nickel-cadmium (Ni/Cd) battery degradation estimation by measuring the capacity of over 400 used cordless-telephone batteries using a discharge-current-pulse technique. The capacity is calculated from the change in battery voltage after the current pulse is applied, using an equation that we developed. Battery degradation is represented by a percentage of the capacity based on the nominal one. To estimate the accuracy of the degradation estimation, we compare capacity Qe estimated from the current pulse with the capacity Qa measured by discharging the batteries. The Qe estimated from the current pulse was within a range of 20% of error indicated by (Qe-Qa) for 47% of the tested batteries. The Qe of 51% of the batteries, however, was underestimated and exceeded lower limit (-20%) of the error. One reason for the discrepancy could be that the equation is inadequate for estimating the capacity from the current pulse. On the other hand, the capacity Qe of 1% of the batteries was overestimated and exceeded upper limit (+20%) of the error. An internal short is probably the main reason for this.

A multiple channel active noise control (ANC) system with several secondary sources, error sensors, and reference sensors has been used for complicated noise fields. Centralized multiple channel ANC systems have been proposed, however implementation of such systems becomes difficult according to increase of control points. Distributed multiple channel ANC systems which have more than a controller are considered. This paper proposes a new implementation of distributed multiple channel ANC systems based on simultaneous equations methods. In the proposed algorithm, communications between controllers are permitted to distribute the computational burden and to improve the performance of noise reduction. This algorithm shows good performances for noise cancellation and tracking of changes in the error paths.

We propose a method for analyzing trade-off between an environment where a Java mobile code application is running and requirements for the application. In particular, we focus on the security-related problems that originate in low-level security policy of the code-centric style of the access control in Java runtime. As the result of this method, we get feasible requirements with respect to security issues of mobile codes. This method will help requirements analysts to compromise the differences between customers' goals and realizable solutions. Customers will agree to the results of the analysis by this method because they can clearly trace the reasons why some goals are achieved but others are not. We can clarify which functions can be performed under the environment systematically. We also clarify which functions in mobile codes are needed so as to meet the goals of users by goal oriented requirements analysis(GORA). By comparing functions derived from the environment and functions from the goals, we can find conflicts between the environments and the goals, and also find vagueness of the requirements. By resolving the conflicts and by clarifying the vagueness, we can develop bases for the requirements specification.

In this paper, we propose the CMOS implementation of a multiple-valued memory cell using -shaped negative-resistance devices. We first propose the construction of a multiple-stable circuit that consists of -shaped negative-resistance devices from four enhancement-mode MOSFETs without a floating voltage source, and connect this in parallel with a unit circuit. It is shown that the movement of -shaped negative-resistance characteristics in the direction of the voltage axis is due to voltage sources. Furthermore, we propose the construction of a multiple-valued memory cell using a multiple-stable circuit. It is shown that it is possible to write and hold data. If the power supply is switched on, it has a feature which enables operation without any electric charge leakage. It is possible, by connecting -shaped negative-resistance devices in parallel, to easily increase the number of multiple values.

Software agents are knowledgeable, autonomous, situated and interactive software entities. Agents' interactions are of special importance when a group of agents interact with each other to solve a problem that is beyond the capability and knowledge of each individual. Efficiency, performance and overall quality of the multi-agent applications depend mainly on how the agents interact with each other effectively. In this paper, we suggest an agent model by which we can clearly distinguish different agent's interaction scenarios. The model has five attributes: goal, control, interface, identity and knowledge base. Using the model, we analyze and describe possible scenarios; devise the appropriate reasoning and decision making techniques for each scenario; and build a library of reasoning and decision making modules that can be used readily in the design and implementation of multiagent systems.

In the urban area, buildings are the main scatterer which dominate the mobile propagation characteristics. However, reflection, diffraction, and scattering on the building surfaces in the radio environment induce undesirable multipath propagation. Multipath prediction with respect to a building surface has been conventionally based on an assumption that reflection from the surface has a substantial specular direction. However non-specular scattering from the building surface can affect the channel characteristics as well as specular scattering. This paper presents multipath characteristics of non-specular wave scattering from building surface roughness based on the experimental results. Superresolution method was applied as an approach to handle the signal parameters (DoA, ToA) of the individual incoming waves reflected from building surface roughness. The results show that the multipaths can be detected at many scatterers, such as ground, window's glass, window's frames and bricks surface, as well as directly from the transmitter. Most of the scattered waves are arriving closely from specular directions. The measured reflection coefficients were well bounded by reflection coefficients of the theoretically smooth and random rough surface. The Fresnel reflection coefficient formula, considering the finite thickness of the building surface and Gaussian scattering correction, give better prediction for glass and bricks reflection coefficient measurement.

To transfer a small number, we inherently need a small number of bits. However all bit lines on a data bus change their status and redundant power is consumed. To reduce the redundant power consumption, we introduce a concept named active bit. In this paper, we propose a power reduction scheme for data buses using active bits. Suppressing switching activity of inactive bits, we can reduce redundant power consumption. We propose various power reduction techniques using active bits and the implementation methods. Experimental results illustrate up to 54.2% switching activity reduction.

Speech quality of VoIP (Voice over Internet Protocol) may potentially be degraded by transmission errors such as packet loss and delay which are basically inevitable in best-effort communications. This study investigates an error concealment technique for such degradation by using a receiver-based technique called pitch waveform replication. For enhancing the conventional technique, this study proposes a waveform reconstruction technique that also takes account of the pitch variation between the backward and forward frames of gap frames. From experimental results of objective evaluation, it is indicated that the proposed technique may potentially be useful for improving the speech quality, compared with the conventional technique.

A DFT-Based method (DBM) has been proposed to compensate for the performance degradation caused by clipping distortion at the expense of bandwidth expansion. On the other hand, in any communication systems, conventional channel coding methods can be employed to improve performance. In this letter, the performance of the DBM and the channel coding methods (CCM) are compared. Furthermore, we introduce a hybrid system which outperforms both the DBM and the CCM.

Energy consumption has become one of the most critical constraints in the design of portable multimedia systems. For media applications, address buses between processor and data memory consume a considerable amount of energy due to their large capacitance and frequent accesses. This paper studies impacts of memory data organization on the address bus energy. Our experiments show that the address bus activity is significantly reduced by 50% through exploring memory data organization and encoding address buses.

This paper presents time slot assignment algorithms applicable to uplink of space division multiple access (SDMA)/time division multiple access (TDMA) systems with adaptive antennas. In the time slot assignment process for a new terminal in a cell, we consider not only the signal quality of the new terminal but also that of active terminals in the same cell. Intra-cell hand over is performed for an active terminal when its signal quality deteriorates. We evaluate the blocking and forced termination probabilities for pure TDMA systems, sectorized systems, and SDMA/TDMA systems in cellular environments by computer simulations. The simulation results show that the SDMA/TDMA systems have much better performance than the pure TDMA and sectorized systems.

This paper presents a Quiet-Noisy scan technique for low power delay fault testing. The novel scan cell design provides both the quiet and noisy scan modes. The toggling of scan cell outputs is suppressed in the quiet scan mode so the power is saved. Two-pattern tests are applied in the noisy scan mode so the delay fault testing is possible. The experimental data shows that the Quiet-Noisy scan technique effectively reduces the test power to 56% of that of the regular scan. The transition fault coverage is improved by 19.7% compared to an existing toggle suppression low power technique. The presented technique requires very minimal changes in the existing MUX-scan Design For Testability (DFT) methodology and needs virtually no computation. The penalties are area overhead, speed degradation, and one extra control in test mode.

This paper presents an imaging technique using the MUSIC algorithm to localize cylindrical reflectors in cross-borehole radar arrangements. Tomographic measurement, in which a transmitting and a receiving antenna are individually moved in separate boreholes, can be considered as a combination of a transmitting and a receiving array. A decorrelation technique with the transmitting array, which has been proposed for imaging point reflectors, is applied for imaging cylindrical reflectors using the MUSIC algorithm. Simulated and experimental results are shown to verify the validity of this algorithm for cylindrical targets. We analyze the evaluation error caused by the increase in the radius of the cylinder.

A compact, low voltage, low power and wide output operating range CMOS exponential-control variable-gain amplifier has been presented. The gain control range of the proposed variable-gain amplifier can be about 50.7 dB while the maximum linearity error is about -1.09%. For the case of supply voltage VDD = 2 V, the maximum power dissipation is only 1.6 µW. The proposed circuit has been fabricated in a 0.5 µm 2p2m N-well CMOS process. Experimental results are given to confirm the feasibility of the proposed variable gain amplifier. The proposed circuit is expected to be useful in analog signal processing applications.

Online shopping is becoming more and more popular in recent years. However, users are still unable to find what they want on the online market very efficiently. In our previous paper we suggested a system that helps to find short-sleeved T-shirts for young women on the online market. Then we conducted several verification experiments and proved that the system was effective. In this paper, we modified the system by adopting the following schemes in order to make it more versatile; First, all information is presented in a unified format. Second, users are provided with multiple-choice key words. Third, users search results are used to select information that is truly useful for the user. Lastly, we conducted several verification experiments and proved that these schemes were effective.