In this paper, we propose a compact representation of logic functions using Multi-valued Decision Diagrams (MDDs) called heterogeneous MDDs. In a heterogeneous MDD, each variable may take a different domain. By partitioning binary input variables and representing each partition as a single multi-valued variable, we can produce a heterogeneous MDD with 16% smaller memory size than a Reduced Ordered Binary Decision Diagram (ROBDD), and with comparable memory size to Free Binary Decision Diagrams (FBDDs). And also, heterogeneous MDDs have shorter Average Path Length (APL) than ROBDDs and FBDDs. We minimized a large number of benchmark functions to show the compactness of heterogeneous MDDs.

Suppose that we need to design a controller for the system x(t) = A x(t) + B u, u = -K x(t), y(t) = C x(t), where matrices A, B and C are given and K is the matrix to to determine. It is required to determine K so that y(t) should not exceed prescribed value (i.e., the peak of output y(t) is limited). This kind of specification, in general, difficult to satisfy, since the peak ymax of y(t) (we define ymax to be max0 t |y(t)|) is a non-trivial function of design parameter K, which can not be expressed explicitly generally. Therefore, a controller design with such specifications often requires try and error process. In this paper, we approximate ymax in the form of formal power series and give an efficient algorithm to compute the series. We also give a design example of a control system as an application of the algorithm.

A C-Ku band 5-bit MMIC phase shifter using optimized reflective series/parallel LC circuits is presented. The proposed circuit has frequency independent characteristics in the case of 180 phase shift, ideally. Also, an ultra-broad-band circuit design theory for the 180 optimized reflective circuit has derived, which gives optimum characteristics compromising between loss and phase shift error. The fabricated 5-bit MMIC phase shifter with SPDT switch has successfully demonstrated a typical insertion loss of 9.4 dB 1.4 dB, and a maximum RMS phase shift error of 7 over the 6 to 18 GHz band. The measured results validate the proposed design theory of the phase shifter.

By adding an auxiliary transformer to a single-stage single-switch power-factor-corrected converter (S4PFCC), the storage capacitor voltage and its range of voltage change against line voltage change are reduced. In addition, this transformer provides a direct power transfer path for input line to output load to increase the conversion efficiency. High power factor is maintained due to the elimination of dead angle of the input current. This paper presents detailed analysis and optimal design of a discontinuous conduction mode (DCM) boost-flyback S4PFCC with the auxiliary transformer. Experimental results for a 15 V/60 W prototype and with comparison to a S4PFCC without the auxiliary transformer are given to show the proposed approach effective.

The software-defined radio technique translates the traditional hardware radio platform to a flexible software radio platform that can support multiple air interface standards. This work proposes an efficient IF processing architecture based on software-defined radio for 2G GSM/IS-95 and 3G W-CDMA systems. Hardware complexity is estimated by fixed-point simulation. IF processing architecture should be highly flexible and minimally complex. Firstly, a carrier channel is selected from a wide frequency band using a high-resolution numerically controlled oscillator (NCO). Wide-range interpolation/decimation is performed by the cascaded integrator comb (CIC) filter that involves no multiplier nor stores filter coefficients. Both the desired narrowband and the desired wideband signals can be extracted. The look-up table (LUT), based on the distributed arithmetic (DA) algorithm is used to implement the finite impulse response (FIR) filter. Therefore, a small area and high speed can be achieved. The errors caused by truncation, quantization, rounding-off and overflow are predicted using a fixed-point simulation. These predictions will help to evaluate the word-length for VLSI implementation. Finally, ALTERA APEX20KE is used as a target device. One hundred thousand gates are used for the implementation. Thus, the proposed architecture has high processing flexibility and small area.

Reseeding technique is proposed to improve the fault coverage in pseudo-random testing. However most of previous works on reseeding is based on storing the seeds in an external tester or in a ROM. In this paper we present a built-in reseeding technique for LFSR-based test pattern generation. The proposed structure can run both in pseudorandom mode and in reseeding mode. Besides, our method requires no storage for the seeds since in reseeding mode the seeds can be generated automatically in hardware. In this paper we also propose an efficient grouping algorithm based on simulated annealing to optimize test vector grouping. Experimental results for benchmark circuits indicate the superiority of our technique against other reseeding methods with respect to test length and area overhead. Moreover, since the theoretical properties of LFSRs are preserved, our method could be beneficially used in conjunction with any other techniques proposed so far.

A novel audio watermarking based on wavelet modulation is presented. The watermark signals are constructed by M-band wavelet modulation that can increase redundancy to improve the detection performance. In order to maximize the watermarking strength within the perceptual constraints, the watermark signals synthesized from different subbands are separately masked using a frequency auditory model. CDMA technique is implemented to achieve watermarking capacity. Experimental results show that this method is very robust.

Mining traversal patterns on the Internet is one of critical issues for exploring the user access behaviors. In this paper, we propose a new data mining scheme for mining frequent trip traversal patterns on the Internet. First, we define a trip traversal as a historical contiguous sequence of web sites or web pages, which were surfed or visited on an information-providing system by one user. Next, we derive all of the maximal trip traversals by analyzing and filtering these collected trip traversals. For mining the large trip traversals from the maximal trip traversals, we present a data mining scheme integrated with the schemes presented in. Here, the extracted large trip traversals can be thought of as the realistic frequent browsed behaviors for most of users either on a web site or on an information-providing system, such as a proxy server. Finally, we implement and design a data mining system to explore the large trip traversal patterns in order to capture user access patterns to some proxy server.

A novel reconfigurable architecture has been proposed for a mobile terminal receiver that can drastically reduce power dissipation dependant on adjacent channel interference. The proposed design can automatically scale the number of filter coefficients and word length respectively by monitoring the in-band and out-of-band powers. The new architecture performance was evaluated in a simulation UTRA-TDD environment because of the large near far problem caused by adjacent channel interference from adjacent mobiles and base stations. The UTRA-TDD downlink mode was examined statistically and results show that the reconfigurable architectures can save an average of up to 75% power dissipation respectively when compared to a fixed filter length of 57 and word length of 16 bits. This power saving only applies to the filter and ADC, not the whole receiver. This will prolong talk and standby time in a mobile terminal. The average number of taps and bits were calculated to be 14.98 and 10 respectively, for an outage of 97%.

In relation to the Software Defined Radio (SDR) concept, an experimental simulation system was developed. Likewise, verification tests were performed in order to validate the envisaged SDR certification processes including its development, certification, distribution, and software installation assuming the future possibility of exchanging the software in the field.

The Communications Research Laboratory (CRL) started a new project named the New Generation Mobile Network Project in April 2002. The target of this project is the development of new technologies to enable seamless and secure integration of various wireless access networks such as 3rd and 4th generation cellular, wireless LAN, high-speed mobile wireless, wired communications, and broadcasting networks. This paper presents an overview of CRL's new generation mobile communication system that is called The Multimedia Integrated Network by Radio Access Innovation Plus (MIRAI+), as well as details the role of Software Radio Technology (SDR) in MIRAI+.

This paper focuses on the realization of low spurious responses by various bandpass filters (BPFs) using open-ended λ/2 resonators. The first part of this paper gives the resonance characteristics of the open-ended λ/2 resonators when the excitation methods are chosen. Secondly, various BPFs obtained with our methodology are provided. For constructing the BPF, (1) point-coupled resonators, (2) comb-line resonators, (3) quasi comb-line resonators and (4) parallel-coupled resonators are used. It is verified that the presented BPFs can be used to obtain low spurious responses both theoretically and experimentally.

In databases based on a multi-aspects object data model whcih enables multiple aspects of a real-world entity to be represented and to be acquired/lost dynamically, Object Migration (OM) updating membership relationships between an object and classes occurs, as the properties of the object evolve in its lifetime. We have proposed an OM behavior modeling framework using Colored Petri Nets (CPN) to analyze OM behavior. Based on the proposed framework, this paper presents a technique for constructing OM behavior models from OM constraint descriptions and class schemas as its input. The presented technique makes it easy to construct consistent and complete OM behavior models, since OM constraints are described in a simple, modular, and declarative form.

This paper presents the approximate error rates of M-ary phase shift keying (MPSK) for optimum combining (OC) with multiple interferers in a flat Rayleigh fading channel. The approximations, which have been used to evaluate the performance of binary PSK for OC, are extended to the performance analysis of MPSK for OC in the presence of arbitrary numbers of antennas and interferers. The mean eigenvalues of interference-plus-noise covariance matrix are analyzed to compare the approximation techniques, i.e., first-order approximation and the orthongal approximation. Using the moment generating function (MGF)-based method, the approximate error rates of MPSK for OC are derived as the closed-form expressions in terms of the exact error rates of MPSK for MRC. The approximate analytical results show the simple and accurate way to assess the average symbol error rate of MPSK for OC with arbitrary numbers of antennas and interferers.

The application of fault injection in the context of dependability benchmarking is far from being straightforward. One decisive issue to be addressed is to what extent injected faults are representative of the considered faults. This paper proposes an approach to analyze the effects of real and injected faults.

This paper outlines the perspectives on Software Defined Radio (SDR) technology in viewpoint of the standardization of the future mobile communication systems. The activities of ITU-R SG8 Working Party 8F (WP8F) and mITF (mobile IT Forum) of Japan for systems beyond IMT-2000 (B3G) or 4-th generation mobile systems are firstly summarized. The latest discussions relating to SDR technology in the both parties are reported. It is followed by consideration on both expectations and technical issues on SDR in order to realize the technology in the future mobile communication systems. They are clarified in the viewpoint of standardization activity on B3G. Also some regulation issues are lastly summarized.

In this letter, a simple peak-to-average power ratio (PAPR) reduction scheme by using a cyclic-shifted sequence mapping is addressed in OFDM-CDMA systems. The PAPR reduction approach is very simple because of no additional complexity and no side information. Also, this simple approach can be easily combined with a modified selective mapping (SLM) approach, which outperforms the original SLM approach at the expense of one additional side information, guaranteeing approximately same transmitter complexity.

It is expected that per-user customized services are widely used in next generation Personal Communication Network. To provide personalized services for each call, per-user service profiles are frequently referenced, so efficient service profile management is essentially required. To provide service profile based services, typically two schemes can be employed: One is Intelligent Network based Central scheme and the other is IMT-2000 based full replication scheme, we refer to as Follow-Me Replication Unconditional (FMRU). Since the Central scheme only depends on the service call rate and the FMRU is merely dependent on the movement rate, it is apparent that the FMRU scheme outperforms the Central scheme if the call-to-mobility ratio (CMR) is large, and vice versa. In this paper, we propose a new service profile replication schemes, Adaptive Follow-Me Replication Conditional (AFMRC) that determine replication automatically according to the user's varying CMR in real-time. We compared the performance of the AFMRC with the previous non-adaptive Follow-Me Replication Conditional (FMRC) scheme. Performance results indicate that as the CMR of a user changes, AFMRC adapts well compared to the existing schemes.

In the 1960's, the problems of distributed systems management did not exist. Systems were centralized and typically housed in one facility. Over time, however, the power, complexity and connectivity of the computer systems and networks evolved. Today, businesses are dependent on their compute and networking infrastructures to operate and survive. These infrastructures are geographically and functionally distributed, and their management is critical. This paper discusses how distributed systems management has evolved, and what the future may bring.

Holonic Manufacturing Systems (HMSs), in which decisions are made through cooperation among holons (autonomous and cooperative manufacturing entities), eliminate various bottlenecks that exist in conventional systems to adapt to high-variety low-volume production. This paper describes the architecture of HMSs. Issues regarding incremental development and dynamic reconfiguration of cooperation mechanisms themselves, and mechanisms for ensuring stable and safe behaviors of HMSs are also discussed with reference to several proposals, with a view to applying the HMS architecture to large and complicated applications.