This paper presents a middleware system for multi-agents on a distributed system as a general test-bed for bio-inspired approaches. The middleware is unique to other approaches, including distributed object systems, because it can maintain and migrate a dynamic federation of multiple agents on different computers. It enables each agent to explicitly define its own deployment policy as a relocation between the agent and another agent. This paper describes a prototype implementation of the middleware built on a Java-based mobile agent system and its practical applications that illustrates the utility and effectiveness of the approach in real distributed systems.

Since we can accumulate a large amount of data including useless information in recent years, it is important to investigate various extraction method of clusters from data including much noises. The Self-Organizing Map (SOM) has attracted attention for clustering nowadays. In this study, we propose a method of using plural SOMs (TSOM: Tentacled SOM) for effective data extraction. TSOM consists of two kinds of SOM whose features are different, namely, one self-organizes the area where input data are concentrated, and the other self-organizes the whole of the input space. Each SOM of TSOM can catch the information of other SOMs existing in its neighborhood and self-organizes with the competing and accommodating behaviors. We apply TSOM to data extraction from input data including much noise, and can confirm that TSOM successfully extracts only clusters even in the case that we do not know the number of clusters in advance.

We propose in this paper a SOM-like algorithm that accepts online, as inputs, starts and ends of viewing of a multimedia content by many users; a one-dimensional map is then self-organized, providing an approximation of density distribution showing how many users see a part of a multimedia content. In this way "viewing behavior of crowds" information is accumulated as experience accumulates, summarized into one SOM-like network as knowledge is extracted, and is presented to new users as the knowledge is transmitted. Accumulation of multimedia contents on the Internet increases the need for time-efficient viewing of the contents and the possibility of compiling information on many users' viewing experiences. In the circumstances, a system has been proposed that presents, in the Internet environment, a kind of summary of viewing records of many viewers of a multimedia content. The summary is expected to show that some part is seen by many users but some part is rarely seen. The function is similar to websites utilizing "wisdom of crowds" and is facilitated by our proposed algorithm.

Collaboration of growing self-organizing maps (GSOM) and adaptive resonance theory maps (ART) is considered through traveling sales-person problems (TSP).The ART is used to parallelize the GSOM: it divides the input space of city positions into subspaces automatically. One GSOM is allocated to each subspace and grows following the input data. After all the GSOMs grow sufficiently they are connected and we obtain a tour. Basic experimental results suggest that we can find semi-optimal solution much faster than serial methods.

Steganographic methods usually produce distortions in cover images due to the process of embedding secret bits. These distortions are hard to remove, and thus the cover image cannot be recovered. Although the distortions are always small, they cannot be allowed for some sensitive applications. In this paper, we propose a reversible embedding scheme for VQ-compressed images, which allows the original cover image to be completely recovered after the extraction of the secret bits. The embedded payload in the proposed method comprises the secret bits plus the restoration information. In order to reduce the size of payload, we utilized the spatial correlations in the image as the restoration information and then compressed the correlations by a lossless compression method. In addition, an alternative pairing method for codewords was proposed to improve the stegoed image quality and control the embedding capacity. Experimental results showed that the proposed method has the benefit of high efficiency of the steganographic process, high image quality, and adaptive embedding capacity compared with other schemes.

Flexibility, adaptation and distribution have been regarded as major challenges of modern interorganizational workflow. To address these issues, this paper proposes an interorganizational workflow execution framework based on process agents and ECA rules. In our framework, an interorganizational workflow is modeled as a multiagent system with a process agent for each organization. The whole execution is divided into two parts: the intra-execution, which means execution within a same organization, and the inter-execution, which represents interaction between organizations. For intra-execution, we use the method of transforming the graph-based local workflow into block-based workflow to design general ECA rules. ECA rules are used to control internal state transitions and process agents are used to control external state transitions of tasks in the local workflows. Inter-execution is realized by process agent interaction protocols. The proposed approach can provide flexible execution of interorganizational workflow with distributed organizational autonomy and adaptation. A case study of offshore software development is illustrated for the proposed approach.

Data detection based on self organizing maps is presented for hematopoietic tumor patients. Learning data for the maps are generated from the screening data of examinees. The incomplete screening data without some item values is then supplemented by substituting averaged non-missing item values. In addition, redundant items, which are common to all the data and tend to have an unfavorable influence on data detection, are eliminated by a genetic algorithm and/or an immune algorithm. It is basically judged, by observing the label of a winner neuron in the map, whether the data presented to the map belongs to the class of hematopoietic tumors. Some experimental results are provided to show that the proposed methods achieve the high probability of correctly identifying examinees as hematopoietic tumor patients.

In this paper, a novel independent component analysis (ICA) approach is proposed, which is robust against the interference of impulse noise. To implement ICA in a noisy environment is a difficult problem, in which traditional ICA may lead to poor results. We propose a method that consists of noise detection and image signal recovery. The proposed approach includes two procedures. In the first procedure, we introduce a self-organizing map (SOM) network to determine if the observed image pixels are corrupted by noise. We will mark each pixel to distinguish normal and corrupted ones. In the second procedure, we use one of two traditional ICA algorithms (fixed-point algorithm and Gaussian moments-based fixed-point algorithm) to separate the images. The fixed-point algorithm is proposed for general ICA model in which there is no noise interference. The Gaussian moments-based fixed-point algorithm is robust to noise interference. Therefore, according to the mark of image pixel, we choose the fixed-point or the Gaussian moments-based fixed-point algorithm to update the separation matrix. The proposed approach has the capacity not only to recover the mixed images, but also to reduce noise from observed images. The simulation results and analysis show that the proposed approach is suitable for practical unsupervised separation problem.

This paper describes a high power GaN-FET amplifier which is developed for wideband code division multiple access (W-CDMA) base stations. We design a bias network which is symmetrically arranged to the RF line (two way bias network) in order to reduce impedance at a baseband frequency of the multi-carrier W-CDMA signal. As a result, the amplifier with the two way bias network successfully suppressed memory effects. Therefore, the application of a DPD technique to the GaN-FET amplifier with the two way bias network demonstrates almost 20 dB linearity improvement in IM3 and considerable improvement in higher order IMD, resulting in low IMD of less than -50 dBc at the highest ever reported W-CDMA average output power of 76 W.

This paper presents two steganographic methods for JPEG2000 still images which approximately preserve histograms of discrete wavelet transform coefficients. Compared with a conventional JPEG2000 steganography, the two methods show better histogram preservation. The proposed methods are promising candidates for secure JPEG2000 steganography against histogram-based attack.

The Self-Organizing Map (SOM) is an unsupervised neural network introduced in the 80's by Teuvo Kohonen. In this paper, we propose a method of simultaneously using two kinds of SOM whose features are different (the nSOM method). Namely, one is distributed in the area at which input data are concentrated, and the other self-organizes the whole of the input space. The competing behavior of the two kinds of SOM for nonuniform input data is investigated. Furthermore, we show its application to clustering and confirm its efficiency by comparing with the k-means method.

Cache performance optimization is an important design consideration in building high-performance embedded processors. Unlike general-purpose microprocessors, embedded processors can take advantages of application-specific information in optimizing the cache performance. One of such examples is to use modified cache index bits (over conventional index bits) based on memory access traces from key target embedded applications so that the number of conflict misses can be reduced. In this paper, we present a novel fine-grained cache reconfiguration technique which allows an intra-program reconfiguration of cache index bits, thus better reflecting the changing characteristics of a program execution. The proposed technique, called dynamic reconfiguration of index bits (DRIB), dynamically changes cache index bits in the function level. This compiler-directed and fine-grained approach allows each function to be executed using its own optimal index bits with no additional hardware support. In order to avoid potential performance degradation by frequent cache invalidations from reconfiguring cache index bits, we describe an efficient algorithm for selecting target functions whose cache index bits are reconfigured. Our algorithm ensures that the number of cache misses reduced by DRIB outnumbers the number of cache misses increased from cache invalidations. We also propose a new cache architecture, Two-Level Indexing (TLI) cache, which further reduces the number of conflict misses by intelligently dividing indexing steps into two stages. Our experimental results show that the DRIP approach combined with the TLI cache reduces the number of cache misses by 35% over the conventional cache indexing technique.

In this paper, we propose a modified reproduction strategy of a Genetic Algorithm (GA) utilizing a Self-Organizing Map (SOM) with a novel updating rule of binary weight vectors based on a significance of elements of inputs. In this rule, an updating order of elements is decided by considering fitness values of individuals in a population. The SOM with the proposed updating rule can realize an effective reproduction.

In this paper, the thermal characteristic of the GaN HFETs has been analyzed using the hybrid finite element method (FEM). Both the steady and transient state thermal operations are quantitatively studied with the effects of temperature-dependent thermal conductivities of GaN and the substrate materials properly treated. The temperature distribution and the maximum temperatures of the HFETs operated under excitations of continuous-waves (CW) and pulsed-waves (PW) including double exponential shape PW such as electromagnetic pulse (EMP) and ultra-wideband (UWB) signal are studied and compared.

A color filter is the penetrable device adhering red, green, and blue organic color resists onto the surface of glass substrate for application of liquid crystal displays. It is fabricated by several technologies, including lithographic processes of coating, baking, exposing, etching, and rinsing. Inkjet printing technology has potentially implemented on the fabrication of the large-size panel with organic molecular film since this technology offers an efficient and steady production procedure. To achieve the basic specifications and requirements of high color performance, high color purity, high flatten, low reflective, and low production cost, inkjet printing technology will be seriously considered in the color filter manufacturing. Here we present the experimental results on physical and chromatic characteristics of color filters by implementing inkjet printing technology. To verify the chromatic characteristics of the resultant color filters, CIE 1931 chromaticity diagram is adopted to present the coordination of color distribution. For the green color ink, the results are x=0.30950.04, y=0.59120.04, brightness of Y=58.887 for 50 droplets and x=0.31030.04, y=0.57840.04, brightness of Y=60.328 for 41 droplets. For the blue color ink, the result is x=0.14900.04, y=0.10150.04, brightness of Y=8.808. For the red color ink, the result is x=0.5720.04, y=0.3200.04, brightness of Y=27.1.

To clarify the carrier transport mechanism of pentacene field-effect transistors (FETs), the FET characteristics was examined in the region where the drain-source voltage Vds is lower than the saturated voltage. The Ids-Vds characteristics shows the ohmic behavior in the low voltage region, whereas it shows the characteristics explained by the Maxwell-Wagner model. This result clearly indicates that carrier injection from source makes a significant contribution to the carrier transport. It was also shown that the change of Ids-Vds characteristics from the ohmic behavior to the Maxwell-Wagner behavior is similar with the I-V characteristics change from the ohmic to the space charge limited current behavior observed in metal-organic film-metal junctions, including metal-pentacene-metal.

Organic static induction transistors (OSITs) with vertical structure have advantage of lower operational voltage compared to the organic field effect transistors with conventional lateral structure. In this study, OSITs based on pentacene films were applied to fabricate the organic inverters which can operate at low voltage. The experimental results demonstrate that organic inverters based on the OSITs show basic transfer characteristics and a low operational voltage of 2 V.

Organic field-effect transistors (OFETs) based on a composite with the same thiophene backbone were fabricated by spin coating using an annealing solution of poly(3-hexylthiophene) (PAT6) and α, ω-dihexylsexithiophene (DH-6T). The morphology of grains on the non-octadecyltrichlorosilane (OTS) treated and OTS treated gate insulators is granular and tube-like, respectively. The different morphologies of the OFETs with non-OTS treated and OTS-treated gate insulators result in the improvement of field-effect mobility. In the case of poly(ethylene naphthalate) substrate, an OFET with an 89 wt% DH-6T composite corresponding to two molecules of DH-6T per hexylthiophene repeating unit had a carrier mobility of 0.019 cm2/Vs.

We succeeded to fabricate p-n heterojunction and bulkheterojunction small-molecular-weight organic thin-film solar cells by combination of dry (p-type = zinc phthalocyanine, n-type = fullerene) and wet (p-type = tetra-tert-butyl zinc phthalocyanine, n-type = [6,6]-phenyl-C61-buteric acid methyl ester) processes. Relationship between morphologies of semiconducting layers and photovoltaic properties was investigated. The p-n heterojunction organic thin-film solar cells based on dry process, where surface roughness was approximately 2 nm, showed the highest power conversion efficiency of 1.3% in this paper.

A one-dimensional (1-D) full search variable block size motion estimation (VBSME) architecture is presented in this paper. By properly choosing the partial sum of absolute differences (SAD) registers and scheduling the addition operations, the architecture can be implemented with simple control logic and regular workflow. Moreover, only one single-port SRAM is used to store the search area data. The design is realized in TSMC 0.18 µm 1P6M technology with a hardware cost of 67.6K gates. In typical working conditions (1.8 V, 25), a clock frequency of 266 MHz can be achieved.