This paper presents a color demosaicing method by introducing iterative asymmetric average interpolation. Missing primary colors on a Bayer pattern color filter array (CFA) are estimated by an asymmetric average interpolation where less intensity variation is assumed to be of stronger significance, before sharpness of an initial estimate is further improved by an iterative procedure. The iteration is implemented by an observation process followed by a restoration process. The former is modeled by blurring followed by CFA sampling and the latter is completely as same as the color demosaicing method initially applied. Experimental results have shown a favorable performance in terms of PSNR and visual appearance, in particular, in sharpness recovery.

The application of neural networks to the state-feedback guaranteed cost control problem of discrete-time system that has uncertainty in both state and input matrices is investigated. Based on the Linear Matrix Inequality (LMI) design, a class of a state feedback controller is newly established, and sufficient conditions for the existence of guaranteed cost controller are derived. The novel contribution is that the neurocontroller is substituted for the additive gain perturbations. It is newly shown that although the neurocontroller is included in the discrete-time uncertain system, the robust stability for the closed-loop system and the reduction of the cost are attained.

Data clustering is a technique for grouping similar data items together for convenient understanding. Conventional data clustering methods, including agglomerative hierarchical clustering and partitional clustering algorithms, frequently perform unsatisfactorily for large text collections, since the computation complexities of the conventional data clustering methods increase very quickly with the number of data items. Poor clustering results degrade intelligent applications such as event tracking and information extraction. This paper presents an unsupervised document clustering method which identifies topic keyword clusters of the text corpus. The proposed method adopts a multi-stage process. First, an aggressive data cleaning approach is employed to reduce the noise in the free text and further identify the topic keywords in the documents. All extracted keywords are then grouped into topic keyword clusters using the k-nearest neighbor approach and the keyword clustering technique. Finally, all documents in the corpus are clustered based on the topic keyword clusters. The proposed method is assessed against conventional data clustering methods on a web news corpus. The experimental results show that the proposed method is an efficient and effective clustering approach.

This paper describes a distributed video transcoding system that can simultaneously transcode an MPEG-2 video file into various video coding formats with different rates. The transcoder divides the MPEG-2 file into small segments along the time axis and transcodes them in parallel. Efficient video segment handling methods are proposed that minimize the inter-processor communication overhead and eliminate temporal discontinuities from the re-encoded video. We investigate how segment transcoding should be distributed to obtain the shortest total transcoding time. Experimental results show that implementing distributed transcoding on 10 PCs can decrease the total transcoding time by a factor of about 7 for single transcoding and by a factor of 9.5 for simultaneous three kinds of transcoding rates.

We calculated the shielding characteristic of a three-dimensional array of strip conductors by using the electric field integral equation method and its expansion to an array structure. From reflection coefficients, the effective permittivity of the array is calculated. The effective permittivity becomes negative in the frequency range above resonance, in which the electromagnetic waves travel through the material in an evanescent mode and the transmission coefficient becomes very small.

We have studied on the interference test method from IEEE802.11b to IEEE802.11g as an interference source with wide band spectrum by using the opened PW cell, and it is clear that the throughput of IEEE802.11g for only IEEE802.11b Ch.4 signal wave as the interference wave, whose frequency spectrum is almost not overlapping with IEEE802.11g, is almost not interfered by IEEE802.11b, but the throughputs for all other channels from Ch.5 to Ch.8 as the interference wave are interfered and decrease to below 2 Mbps. By comparing with conventional radiated RF electromagnetic field immunity test specified by IEC 61000-4-3, it is clear that the conventional immunity test cannot simulate the interference phenomena from IEEE802.11b to IEEE802.11g. Next, we tried to perform the interference test of the Bluetooth against the wireless LAN IEEE 802.11b as a disturbance source. As a result, it is revealed that the throughput of Bluetooth decreases according to increasing the interference wave level, and communication between EUT (slave) and the master of Bluetooth is interrupted for the interference wave corresponding to Ch.7 (244210 MHz). However, in the conventional immunity test specified by IEC 61000-4-3, the throughput of the Bluetooth does not affect for the all disturbance waves corresponding to the center frequency of bandwidth on the cannel of IEEE802.11b. Therefore, it is needed for the wireless LAN and the Bluetooth to develop new radiated immunity test method, which has the disturbance wave with wide bandwidth.

This paper proposes resource management in Layer 1 Virtual Private Networks (VPNs). We have been proposing Layer 1 VPNs that provide layer 1 services to multiple customers over the single optical network with per VPN control and management capabilities. We have proposed two resource management models for Layer 1 VPNs, which constitute different class of services. One is the shared model, where resources are shared among VPNs. The other is the dedicated model, where resources are explicitly pre-assigned to each VPN. In this paper, after introducing an overview of Layer 1 VPNs, we evaluate several path computation algorithms for these two models focusing on the multi layer network scenario. In the shared model, there are several existing studies for non-VPN cases, but considerations for VPN cases are not investigated. This paper evaluates algorithms originally proposed for non-VPN cases for use in VPN cases. Simulation results show that the path computation algorithm that works as saving layer 1 resources achieves better resource sharing effect. In the dedicated model, the problem is identical to non-VPN cases. There is one conventional algorithm, but amount of available resources is not well considered. We propose a novel path computation algorithm. Simulation results show effectiveness of our proposed algorithm against the conventional algorithm. Furthermore, resource usage efficiency of two resource management models is compared. We analyze and propose applicability of resource management models.

A new generation method of rotating electromagnetic fields (rotating-EM fields) for radio frequency (RF) radiated immunity/susceptibility test and its basic characteristics are described. Two different double-side-band suppressed-carrier (DSB-SC) signals are required for generating the slowly rotating-EM field for the immunity/susceptibility test. These DSB-SC signals are generated by a DSB-SC-signal generator based on the new concept which consists of voltage-variable attenuators, bi-phase switches, a direct-digital synthesizer and a micro processor. Using the DSB-SC-signal generator, the DSB-SC signal of arbitrary RF frequency can be generated more easily than the conventional system. In this paper, the principle of the DSB-SC signal generator and the basic characteristics of the DSB-SC signals generated by the generator are clarified. The measured basic characteristics of the rotating-EM field generated using the new concept are shown and it is confirmed that the field can be applied for the RF immunity/susceptibility test. In addition, the susceptibility test of an equipment under test is made as an example, the validity of our proposed system is established.

Electromagnetic (EM) radiation from a feed cable attached to a printed circuit board (PCB), which is commonly encountered electromagnetic interference (EMI) problem at high-speed electronic PCB designs, is investigated by experimental and finite-difference time-domain (FDTD) modeling. In this paper, we propose and demonstrate a guard-band structure as a method for suppressing the EM radiation from a PCB with a feed cable. A signal trace is located between two ground traces (guard-band: GB). Four different cross-sectional PCB structures, which are commonly used in microwave integrated circuits as typical structures, are used to compare the guard-band structure. Frequency response of common-mode (CM) current, electric field near a PCB, and far electric field (radiated emission) are investigated as characteristics of the EMI. Results show that the shield structure is effective in suppressing the CM current at lower frequency. However, structures in which a conductive plate exists near the signal trace yield resonances with high level peak on CM current, near and far-field. On the other hand, the guard-band structure is more effective than other structures in suppressing the EM radiation in the considered frequency range. Therefore the guard-band will be effective for high-density PCB packaging with high-speed traces.

In spatial multiplexing systems using multiple antennas, the error-rate performance is heavily dependent on the residual channel estimation error. In this letter, we propose a design method that uses the genetic algorithms to optimize training sequences for accurate channel estimation.

Large Area Synchronized (LAS)-CDMA, actually composed of LA codes and pulse compressing LS codes, has been proposed as a most promising scheme in 3G and 4G wireless communications. LS codes are famous for the Zero Correlation Zone (ZCZ) in the auto-correlation and cross-correlation functions, which endows the codes with the capability to perfectly reduce the Multiple Access Interference (MAI) and Inter Symbol Interference (ISI) if the maximum transmission delay is less than the length of ZCZ. In this letter, we provide a general and systematic method to construct LS codes from the set of complete complementary sequences. Our method is much more general than the ordinary LS construction method revealed previously.

Short gap arc V-I characteristics are essential to discussions on behavior of contact arc at opening and closing. From this point of view, some conventional arc V-I characteristics were reviewed and inconvenient points of them for practical use were pointed out: (1) not a few electrode-material-dependent constants needed in the equation of V-I relation, (2) difficulty in the prediction of real arc extinction phenomena. In order to overcome these inconveniences, the author measured short gap arc V-I characteristics originally, and tried to formulate them into a simple form on the assumption that the arc column V-I characteristics are little dependent on electrode materials but the unstable arc region is strongly dependent on electrode materials. Measured arc column voltage was directly proportional to the square root of gap length and inversely proportional to the cube root of arc current. Arc became unstable when arc current decreased near to the value generally known as the minimum arc current. It was not necessarily the case that the arc extinguished completely at the minimum arc current, but, depending on the circuit conditions, the arc often existed discontinuously below the so-called minimum arc current. Simple empirical V-I characteristics were proposed for practical use, together with the unstable arc region as the information for arc extinction phenomena.

Power bus noise problem has become a major concern for both EMC engineers and board designers. A fast algorithm, based on the cavity-mode model, was employed for analyzing resonance characteristics of multilayer power bus stacks interconnected by vias. The via is modeled as an inductance and its value is given by a simple expression. Good agreement between the simulated results and measurements demonstrates the effectiveness of the cavity-mode model, together with the via model.

The four-septum transverse electromagnetic (TEM) cell is like the traditional TEM cell but has four plate-like septa in the internal space. A slowly rotating field can be easily generated in the four-septum TEM cell, thus radiated immunity/susceptibility characteristics of an EUT under arbitrary specific polarizations can be measured without rearranging the test setup. A design approach for the four-septum TEM cell is discussed in this paper. The characteristics of the cell are analyzed based on the telegrapher's equation and decomposition of the transmission mode into four independent modes. Then a design approach is given based on the analytical results. A prototype of the four-septum TEM cell based on the design is constructed and the characteristics of the prototype cell are experimentally evaluated. The validity and effectiveness of the design approach are confirmed.

To guarantee QoS for multicast transmission, admission control for multicast sessions is expected. Probe-based multicast admission control (PBMAC) scheme is a scalable and simple approach. However, PBMAC suffers from the subsequent request problem which can significantly reduce the maximum number of multicast sessions that a network can admit. In this letter, we describe the subsequent request problem and propose an enhanced PBMAC scheme to solve this problem. The enhanced scheme makes use of complementary probing and remarking which require only minor modification to the original scheme. By using a fluid-based analytical model, we are able to prove that the enhanced scheme can always admit a higher number of multicast sessions. Furthermore, we present validation of the analytical model using packet based simulation.

Modern telecom and signal relays have been optimized to carry and switch low signals and to withstand high dielectric strength. Recent designs have extremely small physical dimensions and are comparatively cheap. Small size and low cost also make this type of relay very attractive for industrial and automotive applications. For industrial and automotive applications performance characteristics other than low and stable contact resistance values are of importance. While, for industrial applications, safety aspects and inductive load switching characteristics are of major importance, in automotive applications, high switching currents, inductive and lamp loads and high ambient temperatures are essential. Tests were carried out in order to determine the limitations of small size relays. The results obtained clearly show the unexpectedly high load range which signal relays are able to cover. Despite their small size, these relays can handle switching loads up to several hundred volts and currents up to 5 A. On top of the high switching current there is high excess current capability, and relays can work at extreme ambient temperatures between -55 and more than +105 degrees C.

This paper presents a model and its effect for on-line handwritten Japanese text recognition free from line-direction constraint and writing format constraint such as character writing boxes or ruled lines. The model evaluates the likelihood composed of character segmentation, character recognition, character pattern structure and context. The likelihood of character pattern structure considers the plausible height, width and inner gaps within a character pattern that appear in Chinese characters composed of multiple radicals (subpatterns). The recognition system incorporating this model separates freely written text into text line elements, estimates the average character size of each element, hypothetically segments it into characters using geometric features, applies character recognition to segmented patterns and employs the model to search the text interpretation that maximizes likelihood as Japanese text. We show the effectiveness of the model through recognition experiments and clarify how the newly modeled factors in the likelihood affect the overall recognition rate.

A novel application of fuzzy-neuro approach to protection of double circuit transmission line is demonstrated in this paper. Different system faults on a protected transmission line should be detected and classified rapidly and correctly. Using the proposed approach, fault detection, classification and faulted phase selection could be achieved within a quarter of cycle. Results of performance studies show that the proposed fuzzy-neuro-based module can improve the performance of conventional fault selection algorithms.

This paper proposes a "structuring search space" (SSS) method aimed to accelerate recognition of large character sets. We divide the feature space of character categories into smaller clusters and derive the centroid of each cluster as a pivot. Given an input pattern, it is compared with all the pivots and only a limited number of clusters whose pivots have higher similarity (or smaller distance) to the input pattern are searched in, thus accelerating the recognition speed. This is based on the assumption that the search space is a distance space. We also consider two ways of candidate selection and finally combine them the method has been applied to a practical off-line Japanese character recognizer with the result that the coarse classification time is reduced to 56% and the whole recognition time is reduced to 52% while keeping its recognition rate as the original.

Radiation characteristics of various microstrip MIC passive elements are investigated in detail on the basis of accurate numerical analysis. For this purpose, the FD-TD method combined with the radiation mode theory is used. Summarized results are presented mainly from the viewpoint of making clear how radiation characteristics differ depending upon typical features of element structures and operating frequencies. Particularly important features of this paper are that not only radiation into the space region but also that in the substrate region is studied in detail for the first time. Suggestive remarks are given on positioning of active devices in MIC for avoiding interference from nearby elements.