Accurate on-chip 100-ps/100-µV waveform measurements of signal transition in a large-scale digital integrated circuit clearly demonstrates the correlation of dynamic delay variation with power supply noise waveforms. In addition to the linear dependence of delay increase with the height of static IR drop, the distortion of a signal waveform during a logic transition that is induced by dynamic power supply noise causes significant delay variation. However, an analysis reveals that average modeling of dynamic power supply noise, which is often used in conventional simulation techniques, cannot match the experimentally measured values. Our proposed circuit simulation technique, which incorporates time-domain power supply noise waveform macro models along with parasitic impedance networks, reproduces the delay variation well, even with a relative timing difference among different clock domains. Such basic knowledge can be applied in precise delay calculations that consider dynamic power supply noise, a crucial factor in deep sub-100-nm LSI design.

We investigated relations between torque and elbow joint angle for constant muscle activations in isovelocity flexion movements of the forearm in three normal subjects. The reference angular velocity was from 0 to 90°/s and the applied torque from 0 to 15% of maximum voluntary contraction. Integrated surface electromyograms (IEMGs) of six muscles, torque, angle and angular velocity of the elbow joint were measured. A mathematical model describing the relationship between these variables was constructed with an artificial neural network. We estimated elbow joint torque by presenting different elbow joint angles, constant IEMGs and constant angular velocity to the model. For elbow joint angles greater than 60°, the slope, which was defined as the rate of torque increase with respect to elbow joint angle, was negative. For elbow joint angles less than 50°, the slope changed from positive to negative when the angular velocity increased. This implied that the flexor muscle-elbow joint system could change from unstable to stable when the angular velocity increased.

This letter proposed a linear precoding scheme for the V-BLAST system that requires only knowledge of the statistical CSI; the transmitter does not need the instantaneous CSI. Power allocation on the eigenmodes of the transmit correlation matrix is one way to minimize bit error rate (BER). Simulation results show that the proposed precoding V-BLAST system provides a significant reduction in the BER compared with the conventional V-BLAST systems.

According to the properties found in the algebraic complete decoding method for triple-error-correcting binary Bose-Chaudhuri-Hocquenghem (BCH) codes, a step-by-step complete decoding algorithm of this code is presented.

In this paper, we first briefly discuss the newly emerging Secured JPEG (JPSEC) standard for security services for JPEG 2000 compressed images. We then propose our novel approach for applying authentication to JPEG 2000 images in a scalable manner. Our authentication technique can be used for source authentication, nonrepudiation and integrity verification for the received possibly transcoded JPEG 2000 images in such a way that it is possible to authenticate different resolutions or different qualities extracted or received from a JPEG 2000 encoded image. Three different implementation methods for our authentication technique are presented. Packet-Based Authentication involves using the MD5 hashing algorithm for calculating the hash value for each individual packet in the JPEG 2000 codestream. Hash values are truncated to a specified length to reduce the overhead in storage space, concatenated into a single string, and then signed using the RSA algorithm and the author's private key for repudiation prevention. Resolution-Based Authentication and Quality-Based Authentication methods involve generating a single hash value from all contiguous packets from each entire resolution or each entire quality layer, respectively. Our algorithms maintain most of the inherent flexibility and scalability of JPEG 2000 compressed images. The resultant secured codestream is still JPEG 2000 compliant and compatible with JPEG 2000 compliant decoders. Also, our algorithms are compatible with the Public Key Infrastructure (PKI) for preventing signing repudiation from the sender and are implemented using the new JPSEC standard for security signaling.

This paper presents a linear constrained minimum variance multiuser detection (MUD) scheme for DS-CDMA systems, which makes full use of the available spreading sequences of the users as well as the relevant channel information of the incoming rays in the construction of the constraint matrix. To further enhance the performance, a statistical optimum filter bank in combination with the developed minimum variance MUD with the partitioned linear interference canceller (PLIC) as the underlying structure is also addressed. The determination of the filter bank coefficients, however, calls for computationally demanding nonlinear programming. To alleviate the computational overhead, an iterative procedure is also proposed, which solves the Rayleigh quotient in each iteration. Furthermore, the expressions of the output signal to interference plus noise ratio (SINR) are also determined to provide further insights into the proposed approach. Conducted simulations validate the new scheme.

This paper introduces a common database, an evaluation framework, and its baseline recognition results for in-car speech recognition, CENSREC-3, as an outcome of the IPSJ-SIG SLP Noisy Speech Recognition Evaluation Working Group. CENSREC-3, which is a sequel to AURORA-2J, has been designed as the evaluation framework of isolated word recognition in real car-driving environments. Speech data were collected using two microphones, a close-talking microphone and a hands-free microphone, under 16 carefully controlled driving conditions, i.e., combinations of three car speeds and six car conditions. CENSREC-3 provides six evaluation environments designed using speech data collected in these conditions.

An integrate-and-fire-type spiking feedback network is discussed in this paper. In our spiking neuron model, analog information expressing processing results is given by the relative relation of spike firing. Therefore, for spiking feedback networks, all neurons should fire (pseudo-)periodically. However, an integrate-and-fire-type neuron generates no spike unless its internal potential exceeds the threshold. To solve this problem, we propose negative thresholding operation. In this paper, this operation is achieved by a global excitatory unit. This unit operates immediately after receiving the first spike input. We have designed a CMOS spiking feedback network VLSI circuit with the global excitatory unit for Hopfield-type associative memory. The circuit simulation results show that the network achieves correct association operation.

In this paper, a novel cost effective interconnection network for two-way pipelined SIMD-based reconfigurable computing processor is proposed. Our reconfigurable computing engine is composed of the SIMD-based function units, flexible interconnection networks, and two-bank on-chip memories. In order to connect the function units, the reconfigurable network is proposed to connect all neighbors of each function unit. The proposed interconnection network is a kind of full and bidirectional connection with the data duplication to perform the data-parallelism applications efficiently. Moreover, it is a multistage network to accomplish the high flexibility and low hardware cost.

A novel pitch-synchronous auditory-based feature extraction method for robust automatic speech recognition (ASR) is proposed. A pitch-synchronous zero-crossing peak-amplitude (PS-ZCPA)-based feature extraction method was proposed previously and it showed improved performances except when modulation enhancement was integrated with Wiener filter (WF)-based noise reduction and auditory masking. However, since zero-crossing is not an auditory event, we propose a new pitch-synchronous peak-amplitude (PS-PA)-based method to render the feature extractor of ASR more auditory-like. We also examine the effects of WF-based noise reduction, modulation enhancement, and auditory masking in the proposed PS-PA method using the Aurora-2J database. The experimental results show superiority of the proposed method over the PS-ZCPA and other conventional methods. Furthermore, the problem due to the reconstruction of zero-crossings from a modulated envelope is eliminated. The experimental results also show the superiority of PS over PA in terms of the robustness of ASR, though PS and PA lead to significant improvement when applied together.

In this letter, a blind frequency offset estimation algorithm is proposed for OFDM systems. The proposed method exploits the intrinsic phase shift between neighboring samples in a single OFDM symbol, incurred by a frequency offset. The proposed algorithm minimizes a novel cost function, which is the squared error of the candidate frequency offset compensated signals from two different observation windows. Also, the solution of the proposed algorithm is given by an explicit equation, which does not require any iterative calculation. It is shown that the performance of the proposed method is better than those of the conventional methods, especially in the presence of multipath channels. This is due to the fact that the proposed method is insensitive to inter-symbol interference (ISI).

It is well known that the diversity gain attained by DCA (Dynamic Channel Allocation) is generally very high over OFDM (Orthogonal Frequency Division Multiplexing)-based broadband networks. This paper introduces a numerical approach for measuring the performance gain afforded by DCA. In the mathematical analysis, the property of order statistics is adopted to derive the upper bound of the expected throughput via the use of DCA. In the simulation, it was possible to achieve a gain of 5 dB by exploiting multi-user and spectral diversities when the number of users is 16 and the total number of subcarriers is 256.

We have developed a code-division-multiplexing (CDM) transmission scheme for future road-vehicle communication systems, which uses cyclic shifted-and-extended (CSE) codes generated from a basic code with superior auto-correlation characteristics. This paper proposes to use a Quasi-Orthogonal (QO) sequence as the basic code. Its auto-correlation values are zero except at zero and middle shifts. When the CDM transmission is performed by the CSE codes based on the QO sequence, a desired correlation value is, at a receiver, interfered by the auto-correlation value at middle shift. Therefore, an elimination technique for the interfered correlation value is proposed and realizes zero cross-correlation characteristics within the cyclical shift interval. The new CDM transmission scheme based on the proposed scheme is evaluated by computer simulations in terms of the bit-error-rate performance.

An enhanced Ultra Wideband (UWB) signaling scheme that employs PSWF (Prolate Spheroidal Wave Functions)-based orthogonal chip pulses and ternary complementary code sets is proposed for Direct-Sequence (DS) UWB systems. Every information bit of each user is modulated and transmitted over a set of parallel sequences of PSWF-based orthogonal chip pulses and are further assigned to a ternary complementary code set with additional zero padding if necessary. Moreover, the ternary complementary code sets are generated to be mutually orthogonal and assigned to any pair of multiple users. Hence, the mitigation of multipath interference as well as multiple user interference (MUI) can be expected. Furthermore, the ternary code length can be greatly shortened by taking advantage of pulse and code orthogonality. Thus, the proposed transmission scheme is especially suitable for high data rate DS-UWB systems that offer very high flexibility.

This paper provides an overview of the new tendencies in the subjective assessment of the quality of video for Multimedia applications. New subjective assessment methods are here described together with the description of the new general approaches. Some motivations of these new approaches are also here provided.

Research has been actively proposed into how to specify requirements in the upper stream of software development. For example, the main research issues regarding Structured Analysis and Object Oriented Analysis methodologies include requirements elicitation, modeling, and validation of specifications to give a starting point for software development. At the same time, another area of research has emerged that recognizes the importance of guaranteeing requirements quality by goals. As the impact of IT penetrates to mobile devices, information appliances and automobiles, goal oriented requirements engineering (GORE) approaches for performance and safety in embedded systems have been proposed. Non-Functional Requirements (NFRs) such as business strategy, security and privacy, are now being formalized by Requirements Engineering (RE) technologies, because enterprise business is now heavily influenced by IT, for example in e-Business. As IT is fast becoming ubiquitous in society, the importance of Goal Orientation will increase as socio-technology enables visualization of the role of software in social systems. In this paper, we discuss the current states and trends of GORE from the viewpoints of both academia and industry.

We propose a scheme by which Broadcast Satellite/Communication Satellite- radio frequency (BS/CS-RF) converted TV signals are transmitted over optical fiber, and also propose a simultaneous Frequency Modulation (FM) converted CATV and BS/CS-RF converted TV optical transmission system as one of its applications. To confirm the proposals, we demonstrate the simultaneous transport of FM converted CATV signals and BS/CS-RF converted TV signals over a single optical fiber. In the experiments, 40 carriers of AM-VSB CATV channels, 30 carriers of 64-QAM digital TV channels, 8 carriers of FM/TC8PSK BS-TV channels, and 12 carriers of QPSK CS-TV channels are simultaneously transmitted. For optical access network application, the practical transmission length of 15 km over 1.3 µm-zero-dispersion optical fiber can be achieved by using dispersion compensation fiber (DCF).

The computational error of the multilevel fast multipole algorithm is studied. The error convergence rate, achievable minimum error, and error bound are investigated for various element distributions. We will discuss the boundary between the large and small buffer cases in terms of machine precision. The needed buffer size to reach double precision accuracy will be clarified.

Multi-context FPGAs (MC-FPGAs) have multiple memory bits per configuration bit forming configuration planes for fast switching between contexts. The additional memory planes cause a large overhead in area when a number of contexts are used. To overcome the overhead, a fine-grained MC-FPGA architecture using a floating-gate-MOS functional pass gate (FGFP) is presented which merges threshold operation and storage function on a single floating-gate MOS transistor. The test chip is designed using a 0.35 µm CMOS-EPROM technology. The transistor count of the proposed multi-context switch (MC-switch) is reduced to 13% in comparison with SRAM-based one. The total area of the proposed MC-FPGA is reduced to about 56% of that of a conventional SRAM-based MC-FPGA.

This paper overviews the high-speed power-line communication (PLC) technology, and the related standardization and regulatory activities are described. PLC modems of 200 Mbps class become a practical use stage in the West, and the standardization activity is active now. The discussion for deregulation is being continued in also Japan, and regulation values have been proposed. Another topic in this paper is a sensor network application of PLC, which is an indoor fine-grained localization system by acoustic Direct-Sequence Code Division Multiplexed (DS-CDM) signals. The obtained average accuracy of the localization in a 4 m2 plane was 1 cm if there was no obstacle. To realize the localization system, some novel ideas, such as PLC speakers, a synchronization method based on the zero-crossing timing of the mains frequency, and integrated wired/wireless PLC, are introduced.