Placing a guard trace next to a signal line is the conventional technique for reducing the common-mode radiation from a printed circuit board. In this paper, the suppression of common-mode radiation from printed circuit boards having guard traces is estimated and evaluated using the imbalance difference model, which was proposed by the authors. To reduce common-mode radiation further, a procedure for designing a transmission line with guard traces is proposed. Guard traces connected to a return plane through vias are placed near a signal line and they decrease a current division factor (CDF). The CDF represents the degree of imbalance of a transmission line, and a common-mode electromotive force depends on the CDF. Thus, by calculating the CDF, we can estimate the reduction in common-mode radiation. It is reduced not only by placing guard traces, but also by narrowing the signal line to compensate for the variation in characteristic impedance due to the guard traces. Experimental results showed that the maximum reduction in common-mode radiation was about 14 dB achieved by placing guard traces on both sides of the signal line, and the calculated reduction agreed with the measured one within 1 dB. According to the CDF and characteristic impedance calculations, common-mode radiation can be reduced by about 25 dB while keeping the characteristic impedance constant by changing the gap between the signal line and the guard trace and by narrowing the width of the signal line.

This paper proposes a new method to numerically obtain Floquet multipliers which characterize stability of periodic orbits of ordinary differential equations. For sufficiently smooth periodic orbits, we can compute Floquet multipliers using some standard numerical methods with enough accuracy. However, it has been reported that these methods may produce incorrect results under some conditions. In this work, we propose a new iterative method to compute Floquet multipliers using eigenvectors of matrix solutions of the variational equations. Numerical examples show effectiveness of the proposed method.

The paper demonstrates a novel two-peak negative differential resistance (NDR) circuit combining Si-based metal-oxide-semiconductor field-effect-transistor (MOS) and SiGe-based heterojunction bipolar transistor (HBT). Compared to the resonant-tunneling diode, MOS-HBT-NDR has two major advantages in our circuit design. One is that the fabrication of this MOS-HBT-NDR-based application can be fully implemented by the standard BiCMOS process. Another is that the peak current can be effectively adjusted by the controlled voltage. The peak-to-valley current ratio is about 4136 and 9.4 at the first and second peak respectively. It is very useful for circuit designers to consider the NDR-based applications.

Given a sparse linear system, A x = b, we can solve the equivalent system P A PT y = P b, x = PT y, where P is a permutation matrix. It has been known that, for example, when P is the RCMK (Reverse Cuthill-Mckee) ordering permutation, the convergence rate of the Krylov subspace method combined with the ILU-type preconditioner is often enhanced, especially if the matrix A is highly nonsymmetric. In this paper we offer a reordering heuristic for accelerating the solution of large sparse linear systems by the Krylov subspace methods with the ILUT preconditioner. It is the LRB (Line Red/Black) ordering based on the well-known 2-point Red-Black ordering. We show that for some model-like PDE (partial differential equation)s the LRB ordered FDM (Finite Difference Method)/FEM (Finite Element Method) discretization matrices require much less fill-ins in the ILUT factorizations than those of the Natural ordering and the RCMK ordering and hence, produces a more accurate preconditioner, if a high level of fill-in is used. It implies that the LRB ordering could outperform the other two orderings combined with the ILUT preconditioned Krylov subspace method if the level of fill-in is high enough. We compare the performance of our heuristic with that of the RCMK (Reverse Cuthill-McKee) ordering. Our test matrices are obtained from various standard discretizations of two-dimensional and three-dimensional model-like PDEs on structured grids by the FDM or the FEM. We claim that for the resulting matrices the performance of our reordering strategy for the Krylov subspace method combined with the ILUT preconditioner is superior to that of RCMK ordering, when the proper number of fill-in was used for the ILUT. Also, while the RCMK ordering is known to have little advantage over the Natural ordering in the case of symmetric matrices, the LRB ordering still can improve the convergence rate, even if the matrices are symmetric.

We analyze the carrier dynamics in MOSFETs under low-voltage operation. For this purpose the displacement (charging/discharging) current, induced during switching operations is studied experimentally and theoretically for a 90 nm CMOS technology. It is found that the experimental transient characteristics can only be well reproduced in the circuit simulation of low voltage applications by considering the carrier-transit delay in the compact MOSFET model. Long carrier transit delay under the low voltage switching-on operation results in long duration of the displacement current flow. On the other hand, the switching-off characteristics are independent of the bias condition.

Microarray technology has been applied to various biological and medical research fields. A preliminary step to extract any information from a microarray data set is to identify differentially expressed genes between microarray data. The identification of the differentially expressed genes and their commonly associated GO terms allows us to find stimulation-dependent or disease-related genes and biological events, etc. However, the identification of these deregulated GO terms by general approaches including gene set enrichment analysis (GSEA) does not necessarily provide us with overrepresented GO terms in specific data among a microarray data set (i.e., data-specific GO terms). In this paper, we propose a statistical method to correctly identify the data-specific GO terms, and estimate its availability by simulation using an actual microarray data set.

A prototype of a three-axis electro-optic (EO) probe is developed that has the linearity of approximately 0.5 dB in the specific absorption rate (SAR) range of 0.01 to 100 W/kg and the directivities are eight-shaped with cross-axis sensitivity isolation of greater than 30 dB. It is confirmed that electric fields and SAR distributions can be measured using a three-axis EO probe.

In this study, a performance isolation mechanism based on a fuzzy control technique is developed in such a way that ambiguous situations caused when estimating the workload of cluster-based web servers, client request rates, and dynamic request rates can be represented effectively. The proposed mechanism involving a fuzzy-based technique is compared with a non-fuzzy technique in terms of the response time in the 95th percentile. Experiments showed that the proposed technique improves the performance of web servers that provide differentiated services.

H.264 is the latest HDTV video compression standard, which provides a significant improvement in coding efficiency at the cost of huge computation complexity. After transform and quantization, if all the coefficients of the block's residue data are zero, this block is called all-zero block (AZB). Provided that an AZB can be detected early, the process of transform and quantization on an AZB can be skipped, which reduces significant redundant computations. In this paper, a theoretical analysis is performed for the sufficient condition for AZB detection. As a result, a partial sum of absolute difference (SAD) based 44 AZB detection algorithm is derived. And then, a hardware-oriented AZB detection algorithm is proposed by modifying the order of SAD calculation. Furthermore, a quantization parameter (QP) oriented 88 AZB detection algorithm is proposed according to the AZB's statistical analysis. Experimental results show that the proposed algorithm outperforms the previous methods in all cases and achieves major improvement of computation reduction in the range from 6.7% to 42.3% for 44 blocks, from 0.24% to 79.48% for 88 blocks. The computation reduction increases as QP increases.

By use of the shadow theory developed recently, this paper deals with the transverse electric (TE) wave diffraction by a perfectly conductive periodic array of rectangular grooves. A set of equations for scattering factors and mode factors are derived and solved numerically. In terms of the scattering factors, diffraction amplitudes and diffraction efficiencies are calculated and shown in figures. It is demonstrated that diffraction efficiencies become discontinuous at an incident wave number where the incident wave is switched from a propagating wave to an evanescent one, whereas scattering factors and diffraction amplitudes are continuous even at such an incident wave number.

For the acquisition of visual information, the nonuniform sampling process by photoreceptors on the retina occurs at the earliest stage of visual processing. From objects of interest, the human eye receives high visual resolution through nonuniform distribution of photoreceptors. Therefore, this paper proposes auto exposure and focus algorithms for the real-time video camera system based on the visual characteristic of the human eye. For given moving objects, the visual weight is modeled for quantifying the visual importance and the associated auto exposure and focus parameters are derived by applying the weight to the traditional numerical expression, i.e., the DoM (Difference of Median) and Tenengrad methods for auto focus.

With the rapid progress of electronic and information technology, an expectation for the realization of body area network (BAN) by means of ultra wide band (UWB) techniques has risen. Although the signal from a single UWB device is very low, the energy absorption may increase significantly when many UWB devices are simultaneously adorned to a human body. An analysis method is therefore required from the point of view of biological safety evaluation. In this study, two approaches, one is in the time domain and the other is in the frequency domain, are proposed for the specific energy absorption (SA) and the specific absorption rate (SAR) calculation. It is shown that the two approaches have the same accuracy but the time-domain approach is more straightforward in the numerical analysis. By using the time-domain approach, SA and SAR calculation results are given for multiple UWB pulse exposure to an anatomical human body model under the Federal Communications Commission (FCC) UWB limit.

This paper investigates noise reduction performance and performs convergence analysis of a Variable Error Data Normalized Step-Size Least Mean Square (VEDNSS LMS) algorithm. Adopting VEDNSS LMS provides fast convergence at early stages of adaptation while ensuring small final misadjustment. An analysis of convergence and steady-state performance for zero-mean Gaussian inputs is provided. Simulation results comparing the proposed algorithm to existing algorithms indicate its superior performance under various noise and frequency environments.

In market-basket analysis, weighted association rule (WAR) discovery can mine the rules that include more beneficial information by reflecting item importance for special products. In the point-of-sale database, each transaction is composed of items with similar properties, and item weights are pre-defined and fixed by a factor such as the profit. However, when items are divided into more than one group and the item importance must be measured independently for each group, traditional weighted association rule discovery cannot be used. To solve this problem, we propose a new weighted association rule mining methodology. The items should be first divided into subgroups according to their properties, and the item importance, i.e. item weight, is defined or calculated only with the items included in the subgroup. Then, transaction weight is measured by appropriately summing the item weights from each subgroup, and the weighted support is computed as the fraction of the transaction weights that contains the candidate items relative to the weight of all transactions. As an example, our proposed methodology is applied to assess the vulnerability to threats of computer systems that provide networked services. Our algorithm provides both quantitative risk-level values and qualitative risk rules for the security assessment of networked computer systems using WAR discovery. Also, it can be widely used for new applications with many data sets in which the data items are distinctly separated.

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.

MISTY1 is a 64-bit block cipher that has provable security against differential and linear cryptanalysis. MISTY1 is one of the algorithms selected in the European NESSIE project, and it has been recommended for Japanese e-Government ciphers by the CRYPTREC project. This paper reports a previously unknown higher order differential characteristic of 4-round MISTY1 with the FL functions. It also shows that a higher order differential attack that utilizes this newly discovered characteristic is successful against 6-round MISTY1 with the FL functions. This attack can recover a partial subkey with a data complexity of 253.7 and a computational complexity of 264.4, which is better than any previous cryptanalysis of MISTY1.

We have proposed a unique and simple modification to the definition of surface-normal vectors in Physical optics (PO). The modified surface-normal vectors are so defined as that the reflection law is satisfied at every point on the surface. The PO with currents defined by this new surface-normal vector has the enhanced accuracy for the edged scatterers to the level of Geometrical Theory of Diffraction (GTD), though it dispenses with the knowledge of high frequency asymptotic techniques. In this paper, firstly, the remarkable simplicity and the high accuracy of the modified PO as applied to the analysis of Radar Cross Section (RCS) is demonstrated for 2 dimensional problems. Noteworthy is that the scattering not only from edge but also from wedge is accurately predicted. This fringe advantage is confirmed asymptotically by comparing the edge and wedge diffraction coefficients of GTD. Finally, the applicability for three dimensional cube is also demonstrated by comparison with experimental data.

This paper presents the design of a CMOS RF Power Detector (PD) using 0.18 µm standard CMOS technology. The PD is an improved unbalanced source coupled pair incorporating an output differential amplifier and sink current steering. It realizes an input detectable power range of -30 to -20 dBm over 0.1-1 GHz. Also it shows a maximum data rate of 30 Mbps with 2 pF output loading under OOK modulation. The overall current consumption is 1.9 mA under a 1.5 V supply.

A function F:F2n F2n is almost perfect nonlinear (APN) if, for every a 0, b in F2n, the equation F(x)+F(x+a)=b has at most two solutions in F2n. When used as an S-box in a block cipher, it contributes optimally to the resistance to differential cryptanalysis. The function F is almost bent (AB) if the minimum Hamming distance between all its component functions v F, v∈F2n {0} (where "" denotes any inner product in F2n ) and all affine Boolean functions on F2n takes the maximal value 2n-1-2. AB functions exist for n odd only and contribute optimally to the resistance to the linear cryptanalysis. Every AB function is APN, and in the n odd case, any quadratic APN function is AB. The APN and AB properties are preserved by affine equivalence: F F' if F'=A1 F A2, where A1,A2 are affine permutations. More generally, they are preserved by CCZ-equivalence, that is, affine equivalence of the graphs of F: {(x,F(xv)) | x∈ F2n} and of F'. Until recently, the only known constructions of APN and AB functions were CCZ-equivalent to power functions F(x)=xd over finite fields (F2n being identified with F2n and an inner product being x y=tr(xy) where tr is the trace function). Several recent infinite classes of APN functions have been proved CCZ-inequivalent to power functions. In this paper, we describe the state of the art in the domain and we also present original results. We indicate what are the most important open problems and make some new observations about them. Many results presented are from joint works with Lilya Budaghyan, Gregor Leander and Alexander Pott.

In peer-to-peer (P2P) content sharing, users can share their content by contributing their own resources to one another. However, since there is no incentive for contributing contents or resources to others, users may attempt to obtain content without any contribution. To motivate users to contribute their resources to the service, incentive-rewarding mechanisms have been proposed. On the other hand, emerging wireless technologies, such as IEEE 802.11 wireless local area networks, beyond third generation (B3G) cellular networks and mobile WiMAX, provide high-speed Internet access for wireless users. Using these high-speed wireless access, wireless users can use P2P services and share their content with other wireless users and with fixed users. However, this diversification of access networks makes it difficult to appropriately assign rewards to each user according to their contributions. This is because the cost necessary for contribution is different in different access networks. In this paper, we propose a novel incentive-rewarding mechanism called EMOTIVER that can assign rewards to users appropriately. The proposed mechanism uses an external evaluator and interactive learning agents. We also investigate a way of appropriately controlling rewards based on the system service's quality and managing policy.