RHiNET-3/SW is the third-generation switch used in the RHiNET-3 system. It provides both low-latency processing and flexible connection due to its use of a credit-based flow-control mechanism, topology-free routing, and deadlock-free routing. The aggregate throughput of RHiNET-3/SW is 80 Gbps, and the latency is 140 ns. RHiNET-3/SW also provides a hop-by-hop retransmission mechanism. Simulation demonstrated that the effective throughput at a node in a 64-node torus RHiNET-3 system is equivalent to the effective throughput of a 64-bit 33-MHz PCI bus and that the performance of RHiNET-3/SW almost equals or exceeds the best performance of RHiNET-2/SW, the second-generation switch. Although credit-based flow control requires 26% more gates than rate-based flow control to manage the virtual channels (VCs), it requires less VC memory than rate-based flow control. Moreover, its use in a network system reduces latency and increases the maximum throughput compared to rate-based flow control.

In this paper, we investigate Tanner's lower bound for the minimum distance of regular LDPC codes based on combinatorial designs. We first determine Tanner's lower bound for LDPC codes which are defined by modifying bipartite graphs obtained from combinatorial designs known as Steiner systems. Then we show that Tanner's lower bound agrees with or exceeds conventional lower bounds including the BCH bound, and gives the true minimum distance for some EG-LDPC codes.

We propose a normalization scheme of syntactic structures using a binary phrase structure grammar with composite labels. The normalization adopts binary rules so that the dependency between two sub-trees can be represented in the label of the tree. The label of a tree is composed of two attributes, each of which is extracted from each sub-tree, so that it can represent the compositional information of the tree. The composite label is generated from part-of-speech tags using an automatic labelling algorithm. Since the proposed normalization scheme is binary and uses only part-of-speech information, it can readily be used to compare the results of different syntactic analyses independently of their syntactic description and can be applied to other languages as well. It can also be used for syntactic analysis, which performs higher than the previous syntactic description for Korean corpus. We implement a tool that transforms a syntactic description into normalized one based on this proposed scheme. It can help construct a unified syntactic corpus and extract syntactic information from various types of syntactic corpus in a uniform way.

In order for the agent-based applications to be truly autonomous and decentralized, heterogeneous multi-agent systems themselves must communicate and interoperate with each other. To solve the problem, we take a two-step approach. First, message-level interoperability is realized by a gateway agent that interconnects heterogeneous multi-agent systems. Second, higher-level interoperation of conversations, which consist of bi-directional streams of messages, is achieved by dynamically negotiating the interaction protocols. We demonstrate the concept, technique and implementation of integrating multi-agent systems and show how the method improves the assurance of real-world applications in autonomous decentralized systems.

Field Configurable Self-assembly is a novel programmable force field based heterogeneous integration technology. Herein, we demonstrate application of the method to rapid, parallel assembly of similar and dissimilar sub-200 µm GaAs-based light emitting diodes at silicon chip substrates. We also show that the method is compatible with post-process collective wiring techniques for fully planar hybrid integration of active devices.

We propose an image generation method for an immersive multi-screen environment that contains a motion ride. To allow a player to look around freely in a virtual world, a method to generate an arbitrary direction image is required, and this technology has already been established. In our environment, displayed images must also be updated according to the movement of the motion ride in order to keep a consistency between the player's viewpoint and the virtual world. In this paper, we indicate that this updating process can be performed by the similar method to generate looking-around images and the same data format can be applicable. Then we discuss the format in terms of the data size and the amount of calculations need to consider the performance in our display environment, and we propose new image formats which improve on the widely-used formats such as the perspective, or the fish-eye format.

Edge detection has been an essential step in image processing, and there has been much work undertaken to date. This paper inspects a fuzzy mathematical morphology in order to reach a higher-level of edge-image processing. The proposed scheme uses a fuzzy morphological gradient to detect object boundaries, when the boundaries are roughly defined as a curve or a surface separating homogeneous regions. The automatic edge detection algorithm consists of two major steps. First, a new version of anisotropic diffusion is proposed for edge detection and image restoration. All improvements of the new version use fuzzy mathematical morphology to preserve the edge accuracy and to restore the images to homogeneity. Second, the fuzzy morphological gradient operation detects the step edges between the homogeneous regions as object boundaries. This operation uses geometrical characteristics contained in the structuring element in order to extract the edge features in the set of edgeness, a set consisting of the quality values of the edge pixels. This set is prepared with fuzzy logic for decision and selection of authentic edge pixels. For experimental results, the proposed method has been tested successfully with both synthetic and real pictures.

A new algorithm for texture segmentation, called iterative feature extraction (IFE), is proposed to iteratively search and select for an overcomplete wavelet feature vector based on aspect ratio of extrema number (AREN) with a desired window that provides optimal classification accuracy.

Hetero-interface properties of SiO2/4H-SiC on (0001), (11-20), and (03-38) crystal orientations are presented. Epitaxial growth on new crystal orientations, (11-20) and (03-38), is described by comparing with the growth on (0001). Using thermal oxidation with wet oxygen, metal-oxide-SiC (MOS) structure was fabricated. From high-frequency capacitance-voltage characteristics measured at 300 K and 100 K, the interface properties were characterized semi-quantitatively. The interface state density was precisely determined using the conductance method for the MOS structure at 300 K. The new crystal orientations have the lower interface state density near the conduction band edge than (0001). From the characteristics of inversion-type planar MOSFETs, higher channel mobilities were obtained on (03-38) and (11-20) than on (0001). The cause of the difference in the channel mobility is speculated by the difference bond configuration of the three crystal orientations.

As new applications of THz waves emerge, new active and passive components need to be developed. The efficiency of wave guiding systems can be significantly increased with the use of MEMS approaches as well as with the development of new planar antenna concepts with high bunching properties. Generation of sufficient THz power relies on new active devices like Heterostructure Barrier Varactors and cascaded quantum structures, but also in the optimisation of new generation concepts. One of these is photomixing in non-linear materials with very short carrier lifetimes, like low-temperature-grown GaAs.

To meet the highly competitive and dynamic needs in the market, an e-Business company needs to flexibly integrate its heterogeneous database systems together, e.g., the integration of makers and retailers in a Supply Chain Management System (SCM). The customers demand one-click response and also their access requirements change too frequently. Moreover, different retailers and makers in a SCM, being the autonomous entities, have their own specific requirements for stock-cost and opportunity-loss, depending on their local situation that is also changing with time. Under this background, the integrated DBs of the SCM are required to provide real-time response, heterogeneity satisfaction and flexibility to adapt to changing requirements. The conventional approach of strict consistency leads to low response and less flexibility due to the strong interdependence of the systems. In this paper, Autonomous Decentralized Database System has been proposed as an application-oriented database technology based on the concept of autonomy and loose-consistency among the distributed DB systems thus providing real-time, flexibility and high availability. The autonomy in the system has been achieved by defining a data attribute, Allowable Volume, within which each component DB has autonomy to update the data in real-time. Moreover, the system adapts to the dynamically changing heterogeneous access requirements at each DB by managing the distribution of AV among different DBs through an active coordination mechanism. Due to the dynamic and unpredictable environment, the component DBs are provided with complete autonomy for their local and coordination decisions, thus diminishing the interdependency and improving the response time. As the system consists of loosely-connected subsystems, it also has high availability. Therefore, the proposed system provides highly decentralized architecture with flexibility and high availability. The performance of the system has been shown significantly effective by simulating the internet based SCM system, from the communication-cost and response time point of view.

For the mass production of GaN-based electronic devices, growth of AlGaN/GaN heterostructures on substrates larger than 100 mm in diameter is indispensable. In this study, we demonstrate the growth of 100-mm-diameter Al0.26Ga0.74N/GaN heterostructures on sapphire substrates by metalorganic vapor phase epitaxy (MOVPE). The obtained films have specular surfaces, good crystal quality and good uniformity of alloy composition across the entire 100-mm-diameter epitaxial wafer. The bowing value of the 100-mm-diameter epitaxial wafer on c-face sapphire substrates is about 40 µm. This bowing value seems to be preferable for electronic device fabrication processes. These epitaxial wafers show good electrical properties.

The software rejuvenation is a proactive fault management technique for operational software systems which age due to the error conditions that accrue with time and/or load, and is important for high assurance systems design. In this paper, fine-grained shock models are developed to determine the optimal rejuvenation policies which maximize the system availability. We introduce three kinds of rejuvenation schemes and calculate the optimal software rejuvenation schedules maximizing the system availability for respective schemes. The stochastic models with three rejuvenation policies are extentions of Bobbio et al. (1998, 2001) and represent the failure phenomenon due to the exhaustion of the software resources caused by the memory leak, the fragmentation, etc. Numerical examples are devoted to compare three control schemes quantitatively.

The instruction set architecture of MBP-light, a dedicated processor for the DSM (Distributed Shared Memory) management of JUMP-1 is analyzed with a real prototype. The Buffer-Register Architecture proposed for MBP-core improves performance with 5.64% in the home cluster and 6.27% in a remote cluster. Only a special instruction for hashing cluster address is efficient and improves the performance with 2.80%, but other special instructions are almost useless. It appears that the dominant operations in the DSM management program were handling packet queues assigned into the local cluster. Thus, common RISC instructions, especially load/store instructions, are frequently used. Separating instruction and data memory improves performance with 33%. The results suggest that another alternative which provides separate on-chip cache and instructions dedicated for packet queue management is advantageous.

Web Services (WS) have received significant attention recently. Delivering Quality of Service (QoS) on the Internet is a critical and significant challenge for WS community. This article proposes a Web Services Testing Framework (WSTF) for WS participates to perform WS testing. WSTF provides three main distributed components: test master, test agents and test monitor. Test master manages scenarios and generates test scripts. It initiates WS testing by sending test scripts to test agents. Test agents dynamically bind and invoke the WS. Test monitors capture synchronous/asynchronous messages sent and received, attach timestamp, and trace state change information. The benefit to use WSTF is that the user only needs to specify system scenarios based on the system requirements without needing to write test code. To validate the proposed approach, this paper used the framework to test a supply-chain system implemented using WS.

The history of the development of the High Electron Mobility Transistor (HEMT) is an outstanding illustration of how a new device can be successfully marketed. In this paper we discuss a key to successful commercialization of new devices.

Software and its systems are more complicated than a decade ago, and the systems are used for mission critical business, flight control and so on which often require high assurance systems. In this circumstance, we often use black-box testing. The question now arises that black-box testing does not generate numerical value of testing result but empirical. Thus, in this research, we develop and enhance FSM (Finite State Machine) testing method which can produce code coverage rate as numerical value. Our developed FSM testing by code coverage focuses on not only software system behavior but also data. We found higher code coverage rate, which indicates quality of system, by this method than existing black box testing method.

In this paper we present an unsupervised color image segmentation algorithm based on statistical models. We have adopted the Gaussian mixture model to represent the distribution of color feature vectors. A novel deterministic annealing EM and mean field theory from statistical mechanics are used to compute the posterior probability distribution of each pixel and estimate the parameters of the Gaussian Mixture Model. We describe the noncontexture segmentation algorithm that uses a deterministic annealing approach and the contexture segmentation algorithm that uses the mean field theory. The experimental results show that the deterministic annealing EM and mean field theory provide a global optimal solution for the maximum likelihood estimators and that these algorithms can efficiently segment the real image.

Recently, in wired networks, a hierarchical structure has been introduced to improve management and routing. In ad hoc networks, we introduce a hierarchical structure to achieve the same goal. However, it is difficult to introduce the hierarchical structure because all mobile hosts are always moving around the network. So, we proposed the clustering scheme to construct the hierarchical structure before. In this paper, we propose a new hierarchical routing protocol called Hi-TORA based on the clustering scheme. And we show the experimental evaluation of Hi-TORA with respect to the number of control packets, accuracy of packet delivery and hop counts in comparison with TORA.

The conventional clustering method has the unique potential to be the framework for power-conserving ad hoc networks. In this environment, studies on energy-efficient strategies such as sleeping mode and redirection have been reported, and recently some have even been adopted by some standards like Bluetooth and IEEE 802.11. However, consider wireless sensor networks. The devices employed are power-limited in nature, introducing the conventional clustering approach to the sensor networks provides a unique challenge due to the fact that cluster-heads, which are communication centers by default, tend to be heavily utilized and thus drained of their battery power rapidly. In this paper, we introduce a re-clustering strategy and a power-limit constraint for cluster-based wireless sensor networks in order to address the power-conserving issues in such networks, while maintaining the merits of a clustering approach. Based on a practical energy model, simulation results show that the improved clustering method can achieve a lifetime nearly 3 times that of a conventional one.