This paper proposes a method providing efficient test compression. The proposed method is for robust testable path delay fault testing with scan design facilitating two-pattern testing. In the proposed method, test data are interleaved before test compression using statistical coding. This paper also presents test architecture for two-pattern testing using the proposed method. The proposed method is experimentally evaluated from several viewpoints such as compression rates, test application time and area overhead. For robust testable path delay fault testing on 11 out of 20 ISCAS89 benchmark circuits, the proposed method provides better compression rates than the existing methods such as Huffman coding, run-length coding, Golomb coding, frequency-directed run-length (FDR) coding and variable-length input Huffman coding (VIHC).

In orthogonal frequency division multiplexing (OFDM) the multipath exceeding the guard interval (GI) causes inter-symbol interference (ISI) and inter-carrier interference (ICI), thereby making it difficult to achieve high data rate transmission. In this paper, the double window cancellation and combining (DWCC), introduced in [14], is analyzed by investigating SINR distribution under different delay spread channels. The analysis indicates that the extension of processing window in iterative cancellation can have an adverse effect on the performance for small interference levels. In addition, the optimal combining of DWCC and turbo equalization (TE), named TE-DWCC, is investigated by varying the iterative cancellation procedure between DWCC and channel decoder and the decision feedback type such as hard decision feedback (HDF) or soft decision feedback (SDF). Finally, by changing interference level, code rate, and decision feedback type, the performance of TE-DWCC is compared with the conventional canceller that adopts turbo equalization in the exponentially distributed slow fading channel.

The block based motion estimation technique is adopted by various video coding standards to reduce the temporal redundancy in video sequences. The core of that technique is the search algorithm implemented to find the location of the best matched block. Indeed, the full search algorithm is the most straightforward and optimal but computationally demanding search algorithm. Consequently, many fast and suboptimal search algorithms have been proposed. Reduction of the number of location being searched is the approach used to decrease the computational load of full search. In this paper, hybridization between an adaptive search algorithm and the full search algorithm is proposed. The adaptive search algorithm benefits from the correlation within spatial and temporal adjacent blocks. At the same time, a feature domain based matching criteria is used to reduce the complexity resulting from applying the pixel based conventional criteria. It is shown that the proposed algorithm produces good quality performance and requires less computational time compared with popular block matching algorithms.

This paper describes a general quantum lower bounding technique for the communication complexity of a function that depends on the inputs given to two parties connected via paths, which may be shared with other parties, on a network of any topology. The technique can also be employed to obtain a lower-bound of the quantum communication complexity of some functions that depend on the inputs distributed over all parties on the network. As a typical application, we apply our technique to the distinctness problem of deciding whether there are a pair of parties with identical inputs, on a k-party ring; almost matching upper bounds are also given.

This paper presents a scan design for delay fault testability of 2-rail logic circuits. The flip flops used in the scan design are based on master-slave ones. The proposed scan design provides complete fault coverage in delay fault testing of 2-rail logic circuits. In two-pattern testing with the proposed scan design, initial vectors are set using the set-reset operation, and the scan-in operation for initial vectors is not required. Hence, the test application time is reduced to about half that of the enhanced scan design. Because the additional function is only the set-reset operation of the slave latch, the area overhead is small. The evaluation shows that the differences in the area overhead of the proposed scan design from those of the standard scan design and the enhanced scan design are 2.1 and -14.5 percent on average, respectively.

This letter introduces a cost-effective chrominance compensation scheme. The proposed method is applied to both 'INTER 1616' and 'SKIP' modes in only anchor P-pictures. By testing using JVT common test condition, simulation results show that proposed method can obtain average BD-PSNR gains for U and V as 0.14 dB and 0.13 dB, respectively while maintaining almost the same BD-PSNR's for Y. For the range of low bit-rate, it is observed that average BD-PSNR gains for Y, U and V are 0.14 dB, 0.49 dB and 0.53 dB, respectively. Necessary computational complexity is very marginal because the number of anchor P-pictures is very small in comparison with whole coded video sequences. However it can be found that the proposed method can significantly improve the coding efficiencies of color components.

A static dependency pair method, proposed by us, can effectively prove termination of simply-typed term rewriting systems (STRSs). The theoretical basis is given by the notion of strong computability. This method analyzes a static recursive structure based on definition dependency. By solving suitable constraints generated by the analysis result, we can prove the termination. Since this method is not applicable to every system, we proposed a class, namely, plain function-passing, as a restriction. In this paper, we first propose the class of safe function-passing, which relaxes the restriction by plain function-passing. To solve constraints, we often use the notion of reduction pairs, which is designed from a reduction order by the argument filtering method. Next, we improve the argument filtering method for STRSs. Our argument filtering method does not destroy type structure unlike the existing method for STRSs. Hence, our method can effectively apply reduction orders which make use of type information. To reduce constraints, the notion of usable rules is proposed. Finally, we enhance the effectiveness of reducing constraints by incorporating argument filtering into usable rules for STRSs.

In this paper, a Kalman filter-based method for restoration of video images acquired by an in-vehicle camera in foggy conditions is proposed. In order to realize Kalman filter-based restoration, the proposed method clips local blocks from the target frame by using a sliding window and regards the intensities in each block as elements of the state variable of the Kalman filter. Furthermore, the proposed method designs the following two models for restoration of foggy images. The first one is an observation model, which represents a fog deterioration model. The proposed method automatically determines all parameters of the fog deterioration model from only the foggy images to design the observation model. The second one is a non-linear state transition model, which represents the target frame in the original video image from its previous frame based on motion vectors. By utilizing the observation and state transition models, the correlation between successive frames can be effectively utilized for restoration, and accurate restoration of images obtained in foggy conditions can be achieved. Experimental results show that the proposed method has better performance than that of the traditional method based on the fog deterioration model.

For successful data collection in wireless sensor networks, it is important to ensure that the required delivery ratio is maintained while keeping a fair rate for every sensor. Furthermore, emerging high-rate applications might require complete reliability and the transfer of large volume of data, where persistent congestion might occur. These requirements demand a complete but efficient solution for data transport in sensor networks which reliably transports data from many sources to one or more sinks, avoids congestion and maintains fairness. In this paper, we propose congestion-aware and rate-controlled reliable transport (CRRT), an efficient and low-overhead data transport mechanism for sensor networks. CRRT uses efficient MAC retransmission to increase one-hop reliability and end-to-end retransmission for loss recovery. It also controls the total rate of the sources centrally, avoids the congestion in the bottleneck based on congestion notifications from intermediate nodes and centrally assigns the rate to the sources based on rate assignment policy of the applications. Performance of CRRT is evaluated in NS-2 and simulation results demonstrate the effectiveness of CRRT.

This paper deals with a new formulation for the diffraction of a plane wave by a periodic grating. As a simple example, the diffraction of a transverse magnetic wave by a perfectly conductive periodic array of rectangular grooves is discussed. On the basis of a shadow hypothesis such that no diffraction takes place and only the reflection occurs with the reflection coefficient -1 at a low grazing limit of incident angle, this paper proposes the scattering factor as a new concept. In terms of the scattering factor, several new formulas on the diffraction amplitude, the diffraction efficiency and the optical theorem are obtained. It is newly found that the scattering factor is an even function due to the reciprocity. The diffraction efficiency is defined for a propagating incident wave as well as an evanescent incident wave. Then, it is theoretically found that the 0th order diffraction efficiency becomes unity and any other order diffraction efficiencies vanish when a real angle of incidence becomes low grazing. Numerical examples of the scattering factor and diffraction efficiency are illustrated in figures.

This paper proposes a Inter-symbol Interference (ISI) suppressing method For Orthogonal Frequency Division Multiplexing (OFDM) system. In the environments where the delay spread exceeds the guard interval, the occurrence of ISI results in a degradation of system performance. A receiving method based on the Equivalent Transmission Path (ETP) model is proposed for Single-Input Multiple-Output (SIMO) OFDM system. Compared to the receiving scheme using Maximal Ratio Combining (MRC) method, the proposed one shows better performance in suppressing errors due to ISI. The paper also points out that the ETP-based model can be used for detecting the desired signal in the multi-user OFDM system. Simulation results of the system performance show the effectiveness of the proposed method over the conventional OFDM system in suppressing ISI.

This paper presents a high performance and hardware efficient packet detection structure, which employs a cross correlator for the M-sample time delayed correlation operation and a signal power calculator using the received input samples less than or equal to a zero-padded suffix of length M. We investigate the detailed characteristics of the proposed packet detector. In this paper, the performance of a class of packet detection algorithms in the ultra-wideband (UWB) channel environments is also studied. The best packet detection algorithm for the multi-band orthogonal frequency division multiplexing (MB-OFDM) UWB transmission is determined through analysis and extensive simulations. The results of analysis show that the proposed packet detection structure has advantages in the hardware complexity as well as performance when compared with the existing packet detection structures. In order to effectively conduct the packet detection before the automatic gain control (AGC) mode, we investigate the effects of both a frequency offset and the initial gain level of a variable gain amplifier (VGA) on the performance of the packet detection. We also suggest a VGA gain control technique to enhance the performance of packet detection.

A numerical scheme for the analytic continuation of radiation patterns of the azimuthal coordinate θ into the whole space over the complex plane is given. The scattering data given over the real space [0, 2π] are extended into the complex plane by using the recurrence formulas. An example shows the validity of mathematically exact evaluation for the scattering from polygonal cylinders.

This paper studies two types of documents in which an adversary can forge a signature on a chosen document. One type is that a nonce is padded on an input document. The time-stamp protocol is a good example of this type. Another is a structured document (such as PS or PDF) whose contents are described in a body part and information (such as generated time and a generator) are in a meta part. In fact, this paper shows how to forge a time-stamp, a signature on a PDF and an X.509 certificate by the extended forgery attack and numerical examples. Forged signature by the original or the extended attacks is only accepted by the clients whose length check of zero-field is loosely implemented. As a result, we found that the latest versions of Adobe's Acrobat and Acrobat Reader accept the forged time-stamp and the forged signature on a PDF document. Target of this attack is RSASSA-PKCS1-v1_5, which does not have provable security. We also show the expanded attack might forge the signature of RSASSA-PSS, which has provable security, when the length check of zero-field is omitted or loosely implemented.

Automated static timing analysis methods provide a safe but usually overestimated worst-case execution time (WCET) due to infeasible execution paths. In this paper, we propose a visual language, User Constraint Language (UCL), to obtain a tight WCET estimation. UCL provides intuitive visual notations with which users can easily specify various levels of flow information to characterize valid execution paths of a program. The user constraints specified in UCL are translated into finite automata. The combined automaton, constructed by a cross-production of the automata for program and user constraints, reflects the static structure and possible dynamic behavior of the program. It contains only the execution paths satisfying user constraints. A case study using part of a software program for satellite flight demonstrates the effectiveness of UCL and our approach.

This paper addresses the problem of joint transceiver design for Tomlinson-Harashima Precoding (THP) in the multiuser multiple-input-multiple-output (MIMO) downlink under both perfect and imperfect channel state information at the transmitter (CSIT). For the case of perfect CSIT, we differ from the previous work by performing stream-wise (both inter-user and intra-user) interference pre-cancelation at the transmitter. A minimum total mean square error (MT-MSE) criterion is used to formulate our optimization problem. By some convex analysis of the problem, we obtain the necessary conditions for the optimal solution. An iterative algorithm is proposed to handle this problem and its convergence is proved. Then we extend our designed algorithm to the robust version by minimizing the conditional expectation of the T-MSE under imperfect CSIT. Simulation results are given to verify the efficacy of our proposed schemes and to show their superiorities over existing MMSE-based THP schemes.

The sub-threshold R-MOSFET resistor structure which enables tuning range extension below the threshold voltage in the MOSFET with moderate to weak inversion operation is analyzed in detail. The principal operation of the sub-threshold resistor is briefly described. The analysis of its characteristic based on approximations of a general MOS equation valid for all regions is given along with discussion on design implication and consideration. Experiments and simulations are provided to validate the theoretical analysis and design, and to verify the feasibility at a supply voltage as low as 0.5 V using a low-threshold devices in a 1.8-V 0.18 µm CMOS process.

One of the promising wireless access techniques for the next generation mobile communications systems is multi-carrier code division multiple access (MC-CDMA). MC-CDMA can provide good transmission performance owing to the frequency diversity effect in a severe frequency-selective fading channel. However, the bit error rate (BER) performance of coded MC-CDMA is inferior to that of orthogonal frequency division multiplexing (OFDM) due to the residual inter-code interference (ICI) after frequency-domain equalization (FDE). Recently, we proposed a frequency-domain soft interference cancellation (FDSIC) to reduce the residual ICI and confirmed by computer simulation that the MC-CDMA with FDSIC provides better BER performance than OFDM. However, ideal channel estimation was assumed. In this paper, we propose adaptive decision-feedback channel estimation (ADFCE) and evaluate by computer simulation the average BER and throughput performances of turbo-coded MC-CDMA with FDSIC. We show that even if a practical channel estimation is used, MC-CDMA with FDSIC can still provide better performance than OFDM.

This paper deals with the scattering of a transverse magnetic (TM) plane wave from a perfectly conductive surface with a finite periodic array of rectangular grooves. By use of the method in a previous paper [IEICE TRANS. ELECTRON. VOL.E90-C, no.4, pp.903-906, APRIL 2007], the total scattering cross section is numerically calculated for several different numbers of grooves at a low grazing angle of incidence. It is newly found that, when the corrugation width becomes thousands times of wavelength, the total scattering cross section slightly depends on the groove depth and the period, and becomes almost proportional to square root of the corrugation width with a small correction.

To address the low performance for channel scanning in the DVB-T system, we propose an enhanced front-end algorithm in this paper. The proposed algorithm consists of Auto Scan and Normal Scan, which is a part of the tuning algorithm for front-end (tuner) drivers in the DVB-T receiver. The key idea is that the frequency offset is saved when performing Auto Scan in order to reduce the channel change time for Normal Scan. In addition, the results of a performance evaluation demonstrate that our enhanced front-end algorithm improves the performance of channel scanning significantly, as compared to the generic front-end algorithm.