It is known that all minimum cuts in an edge-weighted undirected graph with n vertices and m edges can be represented by a cactus with O(n) vertices and edges, a connected graph in which each edge is contained in an exactly one cycle. In this paper, we show that such a cactus representation can be computed in O(mn+n2log n) time and O(m) space. This improves the previously best complexity of deterministic cactus construction algorithms, and matches with the time bound of the fastest deterministic algorithm for computing a single minimum cut.

The encryption algorithm Camellia is a 128 bit block cipher proposed by NTT and Mitsubishi, Japan. Since the algebraic degree of the outputs after 3 rounds is greater than 128, designers estimate that it is impossible to attack Camellia by higher order differential. In this paper, we show a new higher order differential attack which controls the value of differential using proper fixed value of plaintext. As the result, we found that 6-round F-function can be attacked using 8th order differentials. The attack requires 217 chosen plaintexts and 222 F-function operations. Our computer simulation took about 2 seconds for the attack. If we take 2-R elimination algorithm, 7-round F-function will be attacked using 8th order differentials. This attack requires 219 chosen plaintexts and 264 F-function operations, which is less than exhaustive search for 128 bit key.

In an order-specified multisignature scheme, one can verify not only a set of signers who have signed the message but also its signing order. Though we have seen several schemes with such properties proposed, none of them is given the security proof against active adversaries. The scheme can be easily modified to be an order-specified multisignature scheme, but still has the restriction that the possible signing orders are only ones of the type of serial signing. In this paper, we propose the first order-specified multisignature scheme, which is shown to be secure against adaptive chosen-message insider attacks in the random oracle model, and which allows the signing orders to form like any series-parallel graphs. The security is shown by using ID-reduction technique, which reduces the security of multisignature schemes to those of multi-round identification schemes. Furthermore, we discuss the efficiency of the proposed scheme and the upper bound of the possible number of participating signers.

This paper develops a modular synthesis algorithm for timed circuits that is dramatically accelerated by partial order reduction. This algorithm synthesizes each module in a hierarchical design individually. It utilizes partial order reduction to reduce the state space explored for the other modules by considering a single interleaving of concurrently enabled transitions. This approach better manages the state explosion problem resulting in a more than 2 order of magnitude reduction in synthesis time. The improved synthesis time enables the synthesis of a larger class of timed circuits than was previously possible.

OPKFDDs (Ordered Pseudo-Kronecker Functional Decision Diagrams) are a data structure that provides compact representation of Boolean functions. The size of OPKFDDs depends on a variable ordering and on decomposition type choices. Finding an optimal representation is very hard and the size of the search space is n! 32n-1, where n is the number of input variables. To overcome the huge search space of the problem, a genetic algorithm is proposed for the generation of OPKFDDs with minimal number of nodes.

The locally optimum rank detector achieves a simpler detector structure when reference observations, in addition to regular observations, are available. Without reference observations, we have to use the sign statistics of regular observations, and using the sign statistics results in a complex detector structure. Instead, more computations are necessary to deal with additional reference observations.

This paper presents efficient file management of a hard disk drive embedded digital satellite receiver. The digital broadcasting technology enables multimedia access via broadcasting systems. The amount of digital data to be processed is increased remarkably as compared to the previous analog broadcasting environments. The efficient digital data storage and management technology are discussed in this paper to cope with these changes. The DSR uses a new file system that is designed by considering disk cluster sizes and limited memories in the system, which is more appropriate than that of general Personal Computers. The proposed system enables us to watch broadcasting and to manage multimedia data efficiently.

The fields in the junctions between straight and curved rectangular waveguides are analyzed by using the method of separating variables. This method was succeeded because the authors developed the method of numerical calculation of the cylindrical functions of complex order. As a result, we numerically calculate the reflection and transmission coefficients in the junctions in various situations, and we compare these results with the results by the perturbation method and with the results by Jui-Pang et al.

This paper addresses a high-order sliding mode control strategy for output tracking of nonholonomic mobile robots. First, we introduce the dynamic model of robots, driving motors and nonslipping kinematics constraint conditions. Second, we decompose the system into linear and nonlinear components via diffeomorphism and nonlinear input transformation. Also we consider parameter variations of robots and deduce the uncertain model of robots. Third, we design a high order sliding mode controller for output tracking of known and uncertain systems, respectively. Finally, we perform numerical simulations, demonstrating that the proposed high-order sliding mode control not only reduces the chattering problem of sliding mode systems, but also has certain robustness properties with respect to uncertainties of robots.

The purpose of this paper is to improve the detection sensitivity of radio interferometry. The development of wideband signal processing techniques is necessary for high-sensitivity radio interferometry. The higher-order sampling technique can achieve wider bandwidth than expensive wide-baseband conversion system. The over sampling technique can improve the quantization loss from 11.89% to 3.99% at the 4-level quantized sampling. Moreover, the digital filter can reduce the folding noise incurred by the non-rectangular frequency response at a sampling process. It is confirmed that the wideband and low-loss A/D conversion system may be realized by implementing the higher-order sampling, over sampling and digital filtering techniques. In this paper, the key features focusing on these advanced techniques for radio astronomy are presented in detail.

For a baseband pulse amplitude modulation (PAM) signal limited to Nyquist frequency, mathematical derivation of the timing recovery for a fourth-law circuit followed by a band-pass filter is carried out. The results show that the derived timing wave is expressed as a function of the pulse shape entering the timing path and the bandpass filter tuned to the pulse repetition frequency.

In this paper, we focus on an image encryption scheme based on a truncated Baker transformation. The truncated Baker transformation globally preserves the original dynamics of Baker transformation but incorporates a random local rotation operator between two neighbor elements in the mapping domain in order to keep a finite precision. It generates binary sequences (the dynamics of elements) which have statistically good features on ergodicity, mixing and chaotic properties. The image encryption scheme extended from the truncated Baker transformation efficiently shuffles the input gray level image satisfying fundamental conditions on confusion and diffusion required for image encryption schemes. However, this scheme uses many binary sequences and thus needs to keep a large volume of secret keys. In order to solve this problem we introduce Peano space-filling curve in this scheme, which remarkably reduce the key size and mapping iterations without deteriorating good shuffling properties attained by this scheme.

In this paper, we propose a novel higher order time-frequency distribution (GDH) for a discrete time signal. This distribution is defined over the original discrete time-frequency grids through a delicate discretization of an equivalent expression of a higher order distribution, for a continuous time signal, in [4]. We also present a constructive design method, for the kernel of the GDH, by which the distribution satisfies (i) the alias free condition as well as (ii) the marginal conditions. Numerical examples show that the proposed distributions reasonably suppress the artifacts which are observed severely in the Wigner distribution and its simple higher order generalization.

Self-ordered mesoporous silicate films from organic-inorganic compound materials are successfully fabricated into the surface photo voltage (SPV) type gas sensor device as a gas adsorption insulator layer. These kinds of gas sensors device exhibit NO gas sensing property dependent on their mesoporous film structure. We are succeeded in indication about a possibility of mesoporous silicate film for the SPV type gas sensor application.

With the progress of integration of circuits and PCBs (Printed Circuit Boards), novel techniques have been required for verification of signal integrity. Noise analysis of the power/ground planes is one of the most important issues. This paper describes a high-speed simulator for PCBs which contain the interconnects with nonlinear terminations. This simulator is based on the environmental tool ASSIST (Assistant System for Simulation Study) constructed for development of the circuit simulators, and is combined with PRIMA (Passive Reduced-Order Interconnect Macromodeling Algorithm). In this simulator, an efficient implementation of PRIMA is considered with using a voltage-controlled current source (VCCS) model. Finally, this simulator is applied to the analysis of power/ground planes of the simple PCBs, and the validity is verified.

This paper proposes a power control algorithm with fast convergence suited for wideband code division multiple access (WCDMA). Conventional algorithms are developed with continuous mode power control not binary mode power control. The new power control algorithm is suggested to support the binary mode power control and to offer the optimal relaxation factor for fast convergence.

A base model should be transmitted first in progressive transmission schemes, and its transmission delay dominates initiation time for rendering. To reduce the initiation time, we restructure the base model to transmit visible vertices and triangles for some specific viewpoints first, and therefore clients can start rendering when parts of model file are received. Simulation results show that only 37.4% - 51.3% of model file are required to start rendering, and hence the initiation time is significantly reduced.

We present a simple solution to secretly sharing a factoring witness (for given N) in a publicly-verifiable manner. Compared to the previous PVSS schemes to secretly sharing a factoring witness, the scheme enjoys the following properties: (1) the formal proofs of security can be given; (2) it is designed to be conceptually simpler; (3) it needs fewer communicated bits and, if not-so low exponent RSA (e.g., e > 219+1) is used in the previous schemes, fewer computations; (4) no general multi-party computation is required in the preparation phase.

In this paper, we consider a switching system modeled by a discrete-time flow model. By simulation, it is shown that a lot of border-collision bifurcations occur since the system is piecewise linear. By using its characteristics, we classify its dynamics into modes, and we define blocks and a kind of Poincare map based on the modes. We calculate occurrence conditions of each block and all the Poincare points by computer-assisted analysis. We consider two bifurcation phenomena, and we show that a Poincare point hits a boundary of the occurrence conditions of a block. So, both bifurcations are indeed border-collision bifurcations.

In this paper, we propose an activity-based estimation scheme to determine the received signal power disparity, that enhances the BER performance of the SIC scheme in a DS/CDMA system considering a practical voice activity factor, and compare BER performance with those of other schemes with or without estimation. Numerical analysis results show that the SIC scheme with the proposed activity-based estimation improves the BER performance compared with that without considering voice activity, and it approaches to that of the ideal estimation as the total number of concurrent users increases. In addition, the higher becomes the maximum attainable SNR, the better becomes the BER performance of the proposed activity-based estimation scheme.