In this paper we propose an objective method for assessing the capability of a speech translation system. It automates the translation paired comparison method, which gives a simple, easy to understand TOEIC score proposed by Sugaya et al., to succinctly evaluate a speech translation system. To avoid the expensive evaluation cost of the original method where large manual effort is required, the new objective method automates the procedure by employing an objective metric such as BLEU and DP-based measure. The evaluation results obtained by the proposed method are similar to those of the original method. Also, the proposed method is used to evaluate the usefulness of a speech translation system. It is then found that our speech translation system is useful in general, even to users with higher TOEIC score than the system's.

In ubiquitous computing, or ubiquitous network environment, many sensors and devices are embedded in the environment. Moreover, information appliances and smart space technologies allow users to enjoy high computational power, which also gives freedom and extrication from traditional computing style that often caused users' inconvenience and restriction of their demands and needs. However, due to the characteristics of ubiquitous computing, application's high adaptability to the changes of environments is required. To achieve this high adaptability of applications, we introduce a design approach of "snapshot-based application." The snapshot-based application can store its status as a snapshot. By utilizing the snapshot, an application can be recreated as it is in the status of the snapshot. In this paper, we propose an application framework named "u-Snap," which realizes snapshot-based applications. We have exemplified the effectiveness of this framework with implementation of "u-Photo," which utilize a snapshot of an application as contextual information that is embedded in a photo image.

Current centralized restoration schemes are unsuitable for the increase of scale and complexity of networks. A novel distributed network partition scheme is proposed in this paper. In this scheme, a large-scale network can be partitioned into some wheellike sub-networks with nuclear nodes. In wheellike sub-networks, ring links and spoke links could provide reciprocal safeguard. Based on such structure, different distributed restoration schemes can be combined for failure restoration. The proposed partition approach has been implemented through computer simulation, and it was tested on practical national-scale optical networks. The simulation result shows that this scheme is practicable and effectual.

This paper presents an optimal load balancing algorithm based on both of the ANFIS (Adaptive Neuro-Fuzzy Inference System) modeling and the FIS (Fuzzy Inference System) for the local status of real servers. It also shows the substantial benefits such as the removal of load-scheduling overhead, QoS (Quality of Service) provisioning and providing highly available servers, provided by the suggested method.

The problem of estimating code timings in DS-CDMA systems with multiple antennas is considered in the presence of multipath time-varying fading channels and near-far environments. We present an efficient algorithm for an approximate maximum likelihood approach of jointly estimating the multipath timings of a desired user for DS-CDMA systems that consist of multiple antennas either uncorrelated or fully correlated in space. The procedures of the algorithm to estimate code-timings are developed in order to better exploit the time-varying characteristics of the fading process. In the multipath fading channels, the solution of the proposed algorithms is based on successively optimizing the criterion for increasing numbers of multipath delays. It is shown via simulation results that the modified approaches of the approximate maximum likelihood algorithm much more improve its acquisition performance in the time-varying fading channels. It is seen that the acquisition performance of multiple antennas based acquisition scheme is much better than that of a single antenna based timing estimator in the presence of multipath fading channels and the near-far problem. Furthermore, it is observed that the proposed algorithms outperform the correlator and MUSIC estimator in the multiuser environments with near-far situation on time-varying Rayleigh fading channels.

We present the Ansari-Bradley-Siegel-Tukey M-type K-nearest neighbor (ABSTM-KNN) filter to remove impulse noise from corrupted images. Extensive simulations have demonstrated that the proposed filter consistently outperforms other filters by balancing the tradeoff between noise suppression and detail preservation.

Process-centered software engineering environments (PSEEs) facilitate controlling complicated software processes. Traditional PSEEs are generally centrally controlled, which may result in the following drawbacks: (1) the server may become a bottleneck and (2) when the server is down, processes need to be suspended. To overcome the drawbacks, we developed a decentralized process engine ADPE (agent-based decentralized process engine). ADPE can be embedded in any PSEE to decentralize the PSEE. This paper presents ADPE.

Given the bivariate polynomial f(x,y), let φ(y) be a root of f(x,y) = 0 with respect to x, i.e. φ(y) is a function of y such that f(φ(y),y) = 0. If φ(y) is analytic at y = 0, then we have its power series expansion φ(y) = α0 + α1y + α2y2 + + αpyp + .(1)Let φ(p)(y) denote φ(y) truncated at yp, i.e. φ(p)(y) = α0 + α1y + α2y2 + + αpyp.(2) It is well-known that we can compute power series roots φ(p)(y) by Newton's method. In fact, given the initial value φ(0)(y) = α0 C, the following Newton's methodφ(k)(y) φ(k-1)(y) - (mod yk+1) (3) computes φ(k)(y) (1 k) in expression (2) efficiently (applying the above formula for k = 1,2,, we can compute the power series root φ(p)(y) of any degree p). The above formula (3) is referred to as "symbolic Newton's method" in this paper. From this formula (3), we can see that the numerical errors in the coefficients αs (s = 0,1,...,k - 1) directly affect the numerical error in the coefficient αk. This implies that the symbolic Newton's method is numerically unstable, i.e., a numerical error in the coefficient αk accumulates as the index k increases. Moreover, with the symbolic Newton's method, even if we need only one coefficient αk, we must compute all coefficients αs (s = 0,1,,k - 1). Thus, when we require only one high degree coefficient αk, the symbolic Newton's method is numerically unstable and inefficient. In this paper, given the integer k (> 0), we present a new algorithm to compute the coefficient αk of (1). The new algorithm is numerically stable and requires no computation of the coefficients other than αk itself.

In this paper, conventional validity indexes are reviewed and the shortcomings of the fuzzy cluster validation index based on inter-cluster proximity are examined. Based on these considerations, a new cluster validity index is proposed for fuzzy partitions obtained from the fuzzy c-means algorithm. The proposed validity index is defined as the average value of the relative intersections of all possible pairs of fuzzy clusters in the system. It computes the overlap between two fuzzy clusters by considering the intersection of each data point in the overlap. The optimal number of clusters is obtained by minimizing the validity index with respect to c. Experiments in which the proposed validity index and several conventional validity indexes were applied to well known data sets highlight the superior qualities of the proposed index.

The rate-distortion optimization (RDO) method is an informative technology that improves the coding efficiency, but increases the computational complexity, of the H.264 encoder. In this letter, a fast Macroblock mode determination algorithm is proposed to reduce the computational complexity of the H.264 encoder. The proposed method reduces the encoder complexity by 55%, while maintaining the same level of coding efficiency.

In this letter, a novel wavelet-based semi-fragile watermarking scheme is presented which exploiting the time-frequency feature of discrete wavelet transform (DWT) and high sensitivity on initial value of chaotic map. We also analyze the robustness to mild modification and fragility to malicious attack of our scheme. Its application includes tamper detection, image verification and copyright protection of multimedia content. Simulation results show the scheme can detect and localize malicious attacks with high peak signal-to-noise ratio (PSNR), while tolerating certain degree of JPEG compression and channel additive white Gaussian noise (AWGN).

This paper presents a multiple constrained subspace based multiuser detector for synchronous long-code downlink multirate DS-CDMA systems. The novel receiver adapts its fractionally-spaced equaliser tap-weights based upon two modes, namely training and decision-directed modes. Switching between two modes is achieved by changing the code constraint in the associated subspace algorithm. Moreover, detection of the desired user requires the knowledge of the desired user's spreading code only. Simulation results show that the proposed receiver is capable of multiple access interference (MAI) suppression and multipath mitigation. Besides, the results reveal the improvement in terms of convergence speed and mean square error (MSE) of the proposed receiver over the existing receiver in both static and dynamic environments.

Communications in locally structured wireless networks, such as ad hoc networks, will play an important role for network services and applications in the ubiquitous networking environments of the future. Most of the time, however, mobile networks are used in much the same way as fixed networks: most of the time, mobile terminals merely access information which is stored in the backbone network. Applications based on the local exchange of information gathered or generated by mobile terminals will open up many novel possibilities. A new online storage system named CAOSS facilitates such exchange and constitutes a building block for various new applications. CAOSS is a server-less system that provides high availability of data in mobile and wireless network environments. We describe CAOSS and its application in a mobile video-information-sharing system named GT. Thanks to the good performance of CAOSS, the GT system gives users a convenient and easy way to share and accumulate video data in a wireless environment. We confirm that CAOSS has strong enough performance to deal with large volumes of video data.

A one-dimensional finite-difference time-domain (FDTD) simulator for ultrafast optical switches based on intersubband transition (ISBT) in GaN/AlN waveguide is described. Influences of the inhomogeneous broadening and the 2D mode profile have been taken into consideration. The ultrafast optical response (τ 185 fs) measured in a GaN/AlN waveguide was successfully reproduced by the simulator. At present, however, the saturation characteristics of the fabricated device are mainly limited by the excess TM loss caused by the dislocation in MBE-grown nitride layers. When the dislocation density is reduced and the structure is optimized, the switching pulse energy will be improved to about 10 pJ. Further reduction ( 1 pJ) will be possible when low-loss submicron waveguides with spot-size converters are developed.

In this paper, we propose a multiple-input multiple-output (MIMO) beamforming scheme for a multiuser system in frequency-selective fading channels. The maximum signal-to-noise and interference ratio (MSINR) is adopted as a criterion to determine the transmit and receive weight vectors. In order to maximize the output SINR over all users, two algorithms for base station are considered: the first algorithm is based on the receive weight vector optimization and the second algorithm is based on an iterative update of both transmit and receive weight vectors. Based on the result of single user MIMO beamforming, we analyze the interference channels cancellation ability of multiuser MIMO system. The first algorithm is a simple method and the second algorithm is a performative solution. Through computer simulations, it is shown that multiuser communication system is achievable using the proposed methods in frequency-selective fading condition.

This paper presents the analysis of the stopping maneuver of the human driver by using a new three-dimensional driving simulator that uses CAVE, which provides stereoscopic immersive vision. First of all, the difference in the driving behavior between 3D and 2D virtual environments is investigated. Secondly, a GMDH is applied to the measured data in order to build a mathematical model of driving behavior. From the obtained model, it is found that the acceleration information has less importance in stopping maneuver under the 2D and 3D environments.

This paper considers the problem of recursive filtering for linear discrete-time systems with uncertain observation. A new approximate adaptive filter with a parallel structure is herein proposed. It is based on the optimal mean square combination of arbitrary number of correlated estimates which is also derived. The equation for error covariance characterizing the mean-square accuracy of the new filter is derived. In consequence of parallel structure of the filtering equations the parallel computers can be used for their design. It is shown that this filter is very effective for multisensor systems containing different types of sensors. A practical implementation issue to consider this filter is also addressed. Example demonstrates the accuracy and efficiency of the proposed filter.

In this letter, we propose the SNR estimator for multipath fading channels. We employ the least squares estimator for estimating the channel and estimate the SNR using the estimated noise variance. The SNR estimation can be used to adapt the demodulation algorithm to enhance its performance, as well as to provide the channel quality information. Simulation results show the performance of SNR estimator.

New diode structures without the field-oxide boundary across the p/n junction for ESD protection are proposed. A NMOS (PMOS) is especially inserted into the diode structure to form the NMOS-bounded (PMOS-bounded) diode, which is used to block the field oxide isolation across the p/n junction in the diode structure. The proposed N(P)MOS-bounded diodes can provide more efficient ESD protection to the internal circuits, as compared to the other diode structures. The N(P)MOS-bounded diodes can be used in the I/O ESD protection circuits, power-rail ESD clamp circuits, and the ESD conduction cells between the separated power lines. From the experimental results, the human-body-model ESD level of ESD protection circuit with the proposed N(P)MOS-bounded diodes is greater than 8 kV in a 0.35-µm CMOS process.

Energy-efficient operations are essential to prolonging the lifetime of wireless sensor networks. Clustering sensor nodes is one approach that can reduce energy consumption by aggregating data, controlling transmission power levels, and putting redundant sensor nodes to sleep. To distribute the role of a cluster head, clustering approaches should be based on efficient cluster configuration schemes. Therefore, low overhead in the cluster configuration process is one of the key constraints for energy-efficient clustering. In this paper, we present an autonomous clustering approach using a coverage estimation-based self-pruning algorithm. Our strategy for clustering is to allow the best candidate node within its own cluster range to declare itself as a cluster head and to dominate the other nodes in the range. This same self-declaration strategy is also used in the active sensor election process. As a result, the proposed scheme can minimize clustering overheads by obviating both the requirements of collecting neighbor information beforehand and the iterative negotiating steps of electing cluster heads. The proposed scheme allows any type of sensor network application, including spatial query execution or periodic environment monitoring, to operate in an energy-efficient manner.