In this paper, we propose a driver identification method that is based on the driving behavior signals that are observed while the driver is following another vehicle. Driving behavior signals, such as the use of the accelerator pedal, brake pedal, vehicle velocity, and distance from the vehicle in front, were measured using a driving simulator. We compared the identification rate obtained using different identification models. As a result, we found the Gaussian Mixture Model to be superior to the Helly model and the optimal velocity model. Also, the driver's operation signals were found to be better than road environment signals and car behavior signals for the Gaussian Mixture Model. The identification rate for thirty driver using actual vehicle driving in a city area was 73%.

This paper describes a newly developed automatic direction control scheme for bi-directional bus repeaters that uses dynamic collaborative driving techniques. Repeater directions are rapidly determined by detecting the direction of control signal propagation through an additional control signal line that is driven by dynamic collaborative drivers. Application to an on-chip peripheral bus reduces control circuit transistor counts by about 75% and the number of control signal lines by about 50% without loss of speed. Experimental results for a 0.18-µm CMOS implementation indicate that the proposed scheme is four times faster than a conventional scheme with no bi-directional bus repeaters.

The changes in fiber strain and fiber loss with temperature are quantitatively evaluated for 0.5 mm UV-coated fiber and three kind of fiber-optic access cables, for dropping and indoor wiring, employing 0.5 mm UV-coated fiber. Measurements of the fiber strain and loss increase are conducted using a quasi-heterodyne interferometer method and a photon-counting optical-time-domain-reflectmeter, respectively, at 1.3 and 1.55 µ m. From the strain characteristics, the following observations are made: (a) In the temperature range from -40 to 20 the fiber strain followed the cable strain quite closely, thus maintaining a tight cable structure and (b) from 20 to 80, the fiber exhibited a lower strain than the cable strain. Furthermore, no loss increase due to temperature change was observed for the 0.5-mm diameter coated fiber and the three type of optical cables.

To realize a secure networking infrastructure, the author is carrying out CUE (Coordinating Users' requirements and Engineering constraints) project with a network carrier and a VLSI manufacture. Since CUE-series data-driven processors developed in the project were specifically designed to be an embedded programmable component as well as a multi-processor element, particular design considerations were taken to achieve real-time multiprocessing capabilities essentially needed in multi-media communication environment. A novel data-driven paradigm is first introduced with special emphasis on VLSI-oriented parallel processing architectures. Data-driven protocol handlings on CUE-p and CUE-v1 are then discussed for their real-time multiprocessing capability without any runtime overheads. The emulation facility RESCUE (Real-time Execution System for CUE-series data-driven processors) was also built to develop scalable chip multi-processors in self-evolutional manner. Based on emulation results, the latest version named CUE-v2 was realized as a hybrid processor enabling simultaneous processing of data-driven and control-driven threads to achieve higher performance for inline processing and to avoid any bottlenecks in sequential parts of real-time programs frequently encountered in actual time-sensitive applications. Effectiveness of the data-driven chip multi-processor architecture will finally be addressed for lower power consumption and scalability to realize future VLSI processors in the sub-100 nm era.

A four-quadrant-input linear transconductor generating a product or a product sum current is proposed. The proposed circuit eliminates the influence of channel length modulation and expands a dynamic input voltage range. As an application of the proposed circuit, the four-quadrant analog multiplier is designed. The four-quadrant analog multiplier consists of the proposed circuit, an input circuit and a class AB current buffer. HSPICE simulation results with 0.35 µm n-well single CMOS process parameter are shown in order to evaluate the proposed circuit.

This paper presents a method of predicting future human driving behavior under the condition that its resultant behavior and past observations are given. The proposed method makes use of a dynamic Bayesian network and the junction tree algorithm for probabilistic inference. The method is applied to behavior prediction for a vehicle assumed to stop at an intersection. Such a predictive system would facilitate warning and assistance to prevent dangerous activities, such as red-light violations, by allowing detection of a deviation from normal behavior.

Content-Addressable Network (CAN) provides a mechanism that could retrieve objects in a P2P network by maintaining indices to those objects in a fully decentralized manner. In the CAN system, index caching is a useful technique for reducing the response time of retrieving objects. The key points of effective caching techniques are to improve cache hit ratio by actively sharing caches distributed over the P2P network with every node and to reduce a maintenance and/or routing overhead for locating the cache of a requested index. In this paper, we propose a new caching technique based on the notion of proxy-type caching techniques which have been widely used in WWW systems. It can achieve active cache sharing by incorporating the concept of proxy caching into the index access mechanism and locate a closer proxy cache of a requested index with a little routing overhead. By the result of simulations, we conclude that it can improve the response time of retrieving indices by 30% compared with conventional caching techniques.

Admission control is becoming an essential technique for IP networks to provide full-fledged multimedia streaming services. Although signaling-based schemes are utilized to achieve this, these are difficult to deploy and can hardly achieve strict admission control taking the properties of packet arrival into consideration. In this paper, we propose a novel admission control strategy called the Tentative Accommodating and Congestion Confirming Strategy (TACCS). The main idea is to accommodate incoming flows tentatively and confirm congestion after a certain period. Since tentative accommodating enables us to generate the same situation as where incoming flows have been accommodated, TACCS makes it possible to control admission considering the properties of packet arrival after they have been accommodated, without collecting resource information in advance. From the results of mathematical analysis, we confirmed that TACCS enabled a domain to control admission without a centralized management agent and we provided guidelines for configuring parameters of TACCS.

A coplanar type lumped-element 6-pole microwave Chebyshev bandpass filter (BPF) of center frequency (f0) 2.0 GHz and fractional bandwidth (FBW) 1.0 % was designed. For the design method, theory of direct coupled resonator filters using K-inverters was employed. Coplanar type lumped-element BPFs are composed of a meander-line L and interdigital C elements. The frequency response was simulated and analyzed using an electromagnetic field simulator (Sonnet-EM). Further, the changes in f0 and FBW of the BPF were also realized by the mechanical tuning method.

This paper examines polarimetric scattering characteristics caused by a dihedral corner reflector of finite size. The dihedral corner reflector is a basic model of double-bounce structure in urban area. The detailed scattering information serves the interpretation of Polarimetric Synthetic Aperture Radar (POLSAR) data analysis. The Finite-Difference Time-Domain (FDTD) method is utilized for the scattering calculation because of its simplicity and flexibility in the target shape modeling. This paper points out that there exists a stable double-bounce squint angle region both for perfect electric conductor (PEC) and dielectric corner reflectors. Beyond this stable squint angular region, the scattering characteristics become completely different from the assumed response. A criterion on the double-bounce scattering is proposed based on the physical optics (PO) approximation. The detailed analyses on the polarimetric index (co-polarization ratio) with respect to squint angle and an experimental result measured in an anechoic chamber are shown.

This paper presents an improved gate drive circuit for high power GTO thyristors. The energy-storage/transfer characteristics of an air-core reactor and the fast switching characteristics of FET are employed to make a high gate current of sharp pulse form. The power loss in the gate drive circuit is reduced by using the low resistance and the hysteresis comparator to detect and control the steady on-gate current. The proposed gate drive circuit is analyzed and its usefulness is confirmed by experiments.

We develop several tools to derive quadratic equations from algebraic S-boxes and to prove their linear independence. By applying them to all known almost perfect nonlinear (APN) power functions and the inverse function, we can estimate the resistance against algebraic attacks. As a result, we can show that APN functions have different resistance against algebraic attacks, and especially S-boxes with Gold or Kasami exponents have very weak resistance.

At Eurocrypt '02, Cramer and Shoup [1] proposed a general paradigm to construct practical public-key encryption schemes secure against the adaptive chosen ciphertext attack as well as several concrete examples. One of these example is the scheme based on the quadratic residuosity (QR) problem. However this scheme is less efficient than the other examples. In this paper, we construct a new variant of the Cramer-Shoup encryption scheme which is related to the QR problem. Our variant is more efficient than the scheme based on the QR problem.

The least squares (LS) and the weighted least squares (WLS) algorithms are well known procedures that are used in the design of quadrature mirror filters (QMFs). It is known that these design techniques suffer from pass-band anomaly under certain conditions. A recent method, that overcomes pass-band anomaly for LS QMFs using a frequency sampling design for the initial filter, is extended to WLS design in this letter. A comparison between the modified LS and WLS designs based on experimental results is presented. Although WLS designs have been reported to have superior near-equiripple stop-band performance as compared to LS designs, we find that this is not always true. Specifically, LS designs, with inherent computational and robustness advantages, also have better peak stop-band ripple and transition bandwidth at higher cut-off frequencies than WLS.

To achieve profits derived from multihoming, policy routing is supposed to be necessary. For routers' policy routing, some systems and implementations already exist. In addition to routers' operating systems with policy routing functions, IP Filter and iproute2 are useful for policy routing on routers. But they don't suit for policy routing on multihomed end-hosts because of differences on network environments between routers and end-hosts. In contrast with routers' network environments, there are some dynamic changes of network environments with some types of end-hosts, for example, laptop computers. Therefore, another policy routing system is needed for end-hosts' policy routing, which adapts to dynamic changes of network environment. PMPATH (Policy based MultiPATH routing system) is a policy routing system and designed especially for end-hosts uses. PMPATH uses source address selection as network selection, PMPATH can adapt to dynamic changes of network environment. PMPATH's policies for source address selection are defined in form of address block. PMPATH also provides outgoing interface selection. We implemented PMPATH on NetBSD 2.99.15 and tested its performance on multihomed end-hosts. PMPATH implementation works well even if there are changes of network environment. In this result, it is shown that PMPATH is useful for multihomed end-hosts' policy routing.

In this paper, we propose a method to solve the distributed optimal power flow problem and discuss the associated implementation. We have combined this method with a projected Jacobi (PJ) method and a modified parallel block scaled gradient (MPBSG) method possessing decomposition effects. With the decomposition, our method can be parallel processed and is computationally efficient. We have tested our method for distributed OPF problems on numerous power systems. As seen from the simulation results, our method achieved a dramatic speed-up ratio compared with the commercial IMSL subroutines.

This letter describes an efficient architecture for a Software Defined Radio (SDR) Wideband Code Division Multiple Access (WCDMA) receiver using for high performance wireless communication systems. The architecture is composed of a Radio Frequency (RF) front-end, an Analog-to-Digital Converter (ADC), and a Quadrature Amplitude Modulation (QAM) demodulator. A coherent demodulator, with a complete digital synchronization scheme, achieves the bit-error rate (BER) of 10-6 with the implementation loss of 0.5 dB for a raw Quadrature Phase Shift King (QPSK) signal.

With VLSI design development, the increasingly severe power problem requests to minimize clock routing wirelength so that both power consumption and power supply noise can be alleviated. In contrast to most of traditional works that handle this problem only in clock routing, we propose to navigate standard cell register placement to locations that enable further less clock routing wirelength and power. To minimize adverse impacts to conventional cell placement goals such as signal net wirelength and critical path delay, the register placement is carried out in the context of a quadratic placement. The proposed technique is particularly effective for the recently popular prescribed skew clock routing. Experiments on benchmark circuits show encouraging results.

NAT-PT and DSTM are becoming more widespread as de-facto standards for IPv6 dominant network deployment. But few researchers have empirically evaluated their performance aspects. In this paper, we compared the performance of NAT-PT and DSTM with IPv4-only and IPv6-only networks on user applications using metrics such as throughput, CPU utilization, round-trip time, and connect/request/response transaction rate.

This paper tackles the problem of detecting a random signal embedded in additive white noise. Although the likelihood ratio test (LRT) is the well-known optimum detector for this problem, it may not be easily realized in applications such as radar, sonar, seismic, digital communications, speech analysis and automatic fault detection in machinery, for which suboptimal quadratic detectors have been extensively employed. In this paper, the relationships between four suboptimal quadratic detection schemes, namely, the energy, matched subspace, maximum deflection ratio as well as spectrum matching detectors, and the LRT are studied. In particular, we show that each of those suboptimal detectors can approach the optimal LRT under certain operating conditions. These results are verified via Monte Carlo simulations.