In this paper, we present the Tangible Media Control System (TMCS), which allows users to manipulate media contents through physical objects in an intuitive way. Currently, most people access digital media contents by exploiting GUI. However, it only provides limited manipulation of the contents. The proposed system, instead of a mouse and a keyboard, adopts two types of tangible objects, i.e. a RFID-enabled object and a tracker-embedded object. The TMCS enables users to easily access and control digital media contents through tangible objects. In addition, it supports an interactive media controller which can be used to synthesize media contents according to users' taste. It also offers personalized contents, which suits users' preferences, by exploiting context such as the users' profile and situational information. Accordingly, the TMCS demonstrates that tangible interfaces with context can provide more effective interfaces to satisfy users' demands. Therefore, the proposed system can be applied to various interactive applications such as multimedia education, entertainment, multimedia editor, etc.

Digital watermarking used for fingerprinting may receive a collusion attack; two or more users collude, compare their data, find a part of embedded watermarks, and make an unauthorized copy by masking their identities. In this paper, assuming that at most c users collude, we give a characterization of the fingerprinting codes that have the best security index in a sense of "(c,p/q)-secureness" proposed by Orihara et al. The characterization is expressed in terms of intersecting families of sets. Using a block design, we also show that a distributor of data can only find asymptotically a set of c users including at least one culprit, no matter how good fingerprinting code is used.

This letter investigates a distinct set of complex unitary matrices for differential space time coding by using QPSK modulation. The numerical results show that the properly selection of the initial transmission matrix and the set of unitary matrices can efficiently improve the bit error rate (BER) performance, especially for the antennas correlated fading channel. The computer simulations are evaluated over slow and fast Rayleigh fading channels.

The adaptive Volterra filter (AVF) is attractive in adaptive filtering applications because its expansion is a linear combination of the input and output signals. However, the formidable computational work of AVF is prohibitive for practical applications. In this letter, we present a parallel fast recursive least squares (RLS) second-order adaptive Volterra filter (PAVF) to reduce computational load. Our discussion is based on the approach of the fast RLS AVF [3], by which the computational complexity has been reduced to O(N3) multiplications per time instant, where O(·) denotes "order of," and N is the filter length. Proposed PAVF consists of several subfilters partitioned from the conventional AVF, with parallel implementation, the computational work can be reduced effectively. Several simulation results are presented to validate the proposed method.

Face motion is composed of rigid motion and non-rigid motion. The rigid motion occurs from movements of the human head and the non-rigid motion derives from human's facial expression. In this paper, we present a technique for estimating these rigid/non-rigid motions of the human face simultaneously. First, we test whether the face motion is rigid. If it is rigid motion, we estimate the translation and rotation parameters over image sequences. Otherwise, the non-rigid motion parameters based on the spring-mass-damper (SMD) model are estimated using optical flow. We separate the rigid motion parameters explicitly from the non-rigid parameters for parameters de-coupling, so that we can achieve the face motion estimation more accurately and more efficiently. We will describe the details of our methods and show their efficacy with experiments.

It has been a very important issue to evaluate the performance of transmission control protocol (TCP), and the importance is still growing up because TCP will be deployed more widely in future wireless as well as wireline networks. It is also the reason why there have been a lot of efforts to analyze TCP performance more accurately. Most of these works are focusing on overall TCP end-to-end throughput that is defined as the number of bytes transmitted for a given time period. Even though each TCP's fast recovery strategy should be considered in computation of the exact time period, it has not been considered sufficiently in the existing models. That is, for more detailed performance analysis of a TCP implementation, the fast recovery latency during which lost packets are retransmitted should be considered with its relevant strategy. In this paper, we extend the existing models in order to capture TCP's loss recovery behaviors in detail. On the basis of the model, the loss recovery latency of three TCP implementations can be derived with considering the number of retransmitted packets. In particular, the proposed model differentiates the loss recovery performance of TCP using selective acknowledgement (SACK) option from TCP NewReno. We also verify that the proposed model reflects the precise latency of each TCP's loss recovery by simulations.

This paper presents new algorithms for the Tate pairing on a prime field. Recently, many pairing-based cryptographic schemes have been proposed. However, computing pairings incurs a high computational cost and represents the bottleneck to using pairings in actual protocols. This paper shows that the proposed algorithms reduce the cost of multiplication and inversion on an extension field, and reduce the number of calculations of the extended finite field. This paper also discusses the optimal algorithm to be used for each pairing parameter and shows that the total computational cost is reduced by 50% if k = 6 and 57% if k = 8.

Many parallel Fast Fourier Transform (FFT) algorithms adopt multiple stages architecture to increase performance. However, data permutation between stages consumes volume memory and processing time. One FFT array processing mapping algorithm is proposed in this paper to overcome this demerit. In this algorithm, arbitrary 2k butterfly units (BUs) could be scheduled to work in parallel on n=2s data (k=0,1,..., s-1). Because no inter stage data transfer is required, memory consumption and system latency are both greatly reduced. Moreover, with the increasing of BUs, not only does throughput increase linearly, system latency also decreases linearly. This array processing orientated architecture provides flexible tradeoff between hardware cost and system performance. In theory, the system latency is (s2s-k)tclk and the throughput is n/(s2s-ktclk), where tclk is the system clock period. Based on this mapping algorithm, several 18-bit word-length 1024-point FFT processors implemented with TSMC0.18 µm CMOS technology are given to demonstrate its scalability and high performance. The core area of 4-BU design is 2.9911.121 mm2 and clock frequency is 326 MHz in typical condition (1.8 V,25). This processor completes 1024 FFT calculation in 7.839 µs.

The relative permittivity and permeability are discontinuous at the grating profile, and the electric and magnetic flux densities are continuous. As for the method of analysis for scattering waves by surface relief gratings placed in conical mounting, the spatial harmonic expansion approach of the flux densities are formulated in detail and the validity of the approach is shown numerically. The present method is effective for uniform regions such as air and substrate in addition to grating layer. The matrix formulations are introduced by using numerical calculations of the matrix eigenvalue problem in the grating region and analytical solutions separated for TE and TM waves in the uniform region are described. Some numerical examples for linearly and circularly polarized incidence show the usefulness of the flux densities expansion approach.

An inverse scattering problem of estimating the surface impedance for an inhomogeneous half-space is investigated. By virtue of the fact that the far field representation contains the spectral function of the scattered field, complex values of the function are estimated from a set of absolute values of the far field. An approximate function for the spectral function is reconstructed from the estimated complex values by the least-squares sense. The surface impedance is estimated through calculating the field on the surface of the half-space expressed by the inverse Fourier transform. Numerical examples are given and the accuracy of the estimation is discussed.

Current TCP-friendly congestion control mechanisms adjust the packet rate in order to adapt to wired network conditions and obtain a throughput not exceeding that of a TCP connection operating under the same conditions. However, these mechanisms can not be directly applicable to wireless network because there is no way to distinguish congestion losses from wireless channel losses. In this letter, a new loss differentiation algorithm for wired-to-wireless streaming service is described. The approach does not only adjust the sending rate according to the network status, but also provide the useful feedback to the video encoder.

In recent years, considerable attention has been devoted to continuously running software systems whose performance characteristics are smoothly degrading in time. Software aging often affects the performance of a software system and eventually causes it to fail. A novel approach to handle transient software failures due to software aging is called software rejuvenation, which can be regarded as a preventive and proactive solution that is particularly useful for counteracting the aging phenomenon. In this paper, we focus on a high assurance software system with fault-tolerance and preventive rejuvenation, and analyze the stochastic behavior of such a highly critical software system. More precisely, we consider a fault-tolerant software system with two-version redundant structure and random rejuvenation schedule, and evaluate quantitatively some dependability measures like the steady-state system availability and MTTF based on the familiar Markovian analysis. In numerical examples, we examine the dependence of two fault tolerant techniques; design and environment diversity techniques, on the system dependability measures.

There are three well-known approaches to using scan design to apply two-pattern testing: broadside testing (functional justification), skewed-load testing and enhanced scan testing. The broadside and skewed-load testing use the standard scan design, and thus the area overheads are not high. However fault coverage is low. The enhanced scan testing uses the enhanced scan design. The design uses extra latches, and allows scan-in any two-pattern testing. While this method achieves high fault coverage, it causes high area overhead because of extra latches. This paper presents a new scan design where two-pattern testing with high fault coverage can be performed with area overhead as low as the standard scan design. The proposed scan-FFs are based on master-slave FFs. The input of each scan-FF is connected to the output of the master latch and not the slave latch of the previous FF. Every scan-FF maintains the output value during scan-shift operations.

In this paper, we propose a fast multi-resolution block matching algorithm with three resolution levels (upper, middle, and lower levels) for multiple-frame motion estimation (MFME). The main concept of the algorithm is to perform a fast search while maintaining a PSNR performance similar to a full search block matching algorithm (FSBMA). The algorithm combines motion vector prediction using the spatial correlation of motion vectors and a multiple candidate search based on a multi-resolution search. To further reduce the computational complexity, we propose two temporal reduction schemes. To reduce the number of previous reference frames to be processed, the first scheme is applied to the upper level by using the information obtained from the search results of the spatio-temporally adjacent macroblocks (MBs) and the result from the current MB in the middle level of the first reference frame. The other scheme is applied to the lower level by using statistical information. Experimental results show that the proposed algorithm guarantees an average PSNR loss of less than 0.23 dB with dramatically reduced computational complexity as compared to the FSBMA. In particular, for sequences with fast motion or frame skipping, the proposed method provides a more prominent PSNR performance than those of existing fast schemes with a comparable computational complexity.

In this paper, we propose a method for detecting and tracking faces in video sequences in real time. It can be applied to a wide range of face scales. Our basic strategy for detection is fast extraction of face candidates with a Six-Segmented Rectangular (SSR) filter and face verification by a support vector machine. A motion cue is used in a simple way to avoid picking up false candidates in the background. In face tracking, the patterns of between-the-eyes are tracked while updating the matching template. To cope with various scales of faces, we use a series of approximately 1/ scale-down images, and an appropriate scale is selected according to the distance between the eyes. We tested our algorithm on 7146 video frames of a news broadcast featuring sign language at 320240 frame size, in which one or two persons appeared. Although gesturing hands often hid faces and interrupted tracking, 89% of faces were correctly tracked. We implemented the system on a PC with a Xeon 2.2-GHz CPU, running at 15 frames/second without any special hardware.

Surface wave distribution over electromagnetic bandgap (EBG) plate is measured and suppression of surface wave propagation over the EBG is investigated. We used a micro current probe that detects H-field strength of the propagating transverse magnetic (TM) microwave up to 6 GHz. By scanning with the probe over the EBG, we visualized surface wave distribution at various frequencies. This visualized map shows that the EBG plate suppresses the surface wave propagation within the bandgap frequency. We utilized this effect for the antenna reflective shield. By combining the EBG with a microstrip patch antenna, this EBG works as a reflective shield and the front-to-backward radiation ratio of antenna is increased. In this experiment, we fabricated three types of shield board; mushroom type of EBG that has hexagonal textured patches connected with via-holes, textured surface without via-holes, and plane metal. By comparing the surface wave distributions and beam patterns of antenna with various shields, we found that the visualized map of TM surface wave gives us direct and intuitive information and helpful tips in designing the EBG reflective shield for patch antenna.

In the letter we extend our previous work, which applies genetic programming to passive filter synthesis tasks. The extended method deals with the tolerance design considerations. Experimental results show that our method can effectively generate filters which outperform those generated by traditional methods. In addition, it provides filter designers with an effective CAD tool to manage the trade-off between manufacturing yield and circuit cost.

In this paper, an eight-legged resonant element is proposed for a multiband and dual-polarized frequency selective surface (FSS). The FSS element has two resonant frequencies for constructing two reflection bands, of which the separation can be easily controlled by adjusting the shape of the element. The flexibility is demonstrated by the simulated results of transmission responses for various geometrical parameters. And it is shown that introducing resonant-grid and closely-packing techniques can improve the reflection bandwidth. Finally, the good agreement between the measured and the calculated results proves that the eight-legged element is useful for the design of a multiband FSS.

A high quality-factor of active inductor has been implemented by using the 0.18 µm 1P6M CMOS technologies in this work. By adding a feedback resistance and a regulated gain stage transistor into the conventional cascade-grounded approach, the quality-factor and performance of CMOS active inductor can be improved. This novel active inductor demonstrated a maximum quality-factor of 540 and a 3.2 nH inductance at 4.3 GHz, where the self-resonant frequency was 5.4 GHz. An active CMOS bandpass filter was also fabricated including this tunable high quality factor active inductor, performing an insertion loss of 0.2 dB and a return loss more than 32 dB with a tuning range from 3.45 GHz to 3.6 GHz. The input IP3 was -2.4 dBm, and the noise figure was 14.1 dB with a 28 mW dc power consumption.

In the move toward higher clock rates and advanced process technologies, designers of the latest electronic products are finding increasing silicon failure with respect to noise. On the other hand, the minimum dimension of patterns on LSIs is much smaller than the wavelength of exposure, making it difficult for LSI manufacturers to obtain high yield. In this paper, we present a solution to reduce power-supply noise in LSI microchips. The proposed design methodology also considers design for manufacturability (DFM) at the same time as power integrity. The method was successfully applied to the design of a system-on-chip (SOC), achieving a 13.1-13.2% noise reduction in power-supply voltage and uniformity of pattern density for chemical mechanical polishing (CMP).