The demand for highly available software systems has increased dramatically over the past several years. Such systems must be developed using a discipline that supports unanticipated runtime evolution. We characterize the desiderata of a programming model that provides such support, and describe the design and implementation of an architecture satisfying these criteria. The Dynamic Reconfiguration Subsystem (DRSS) is an interceptor-based open container architecture that supports the development of highly available systems by enabling the scalable, dynamic deployment of cross-cutting software modifications. We have implemented a prototype of DRSS using Microsoft's .NET Framework.

Karhunen-Loeve (KL) transform is optimal for many signal detection, communication and filtering applications. An explicit solution of the KL integral equation for a practical case when the covariance function of a stationary process is exponentially oscillating is proposed.

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.

A distributor of digital contents desires to collect users' attributes. On the other hand, the users do not desire to offer the attributes owing to the privacy protection. Previously, an anonymous survey system for attributes statistics is proposed. In this system, asking trusted third parties' helps, a distributor can obtain the correct statistics of users' attributes, such as gender and age, while no information beyond the statistics is revealed. However, the system suffers from the inefficiency of a protocol to generate the statistics, since the cost depends on the number of all the users registering this survey system. This paper proposes an anonymous survey system, where this cost is independent from the number of all the registering users. In this accomplishment, a group signature scheme with attribute tracing is also proposed. A conventional group signature scheme allows a group member to anonymously sign a message on behalf of the group, while only a designated party can identify the signer. The proposed scheme further enables the party to trace signer's attribute.

An Anomaly detection sensor, to detect an abnormal use of system resources or an abnormal behavior of authorized users, uses various measures and decides on the basis of threshold value. However, it has high false alarm rate, and it make it hard to merchandise. Also, it is not easy to have a threshold which is suitable for installation environment. In this paper, we propose a method to automatic generation of proper threshold of each sensor, and the threshold is applied for an integrated decision. Also, we propose a computing method for a correlation of heterogeneous detection sensors. As we use the correlation to integrate and decide the opinions of each sensor, false positive can be greatly reduced.

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.

For radar tracking, the α-β filter and the Kalman filter, both of which do not require large computational requirements, have been widely utilized. However these filters cannot track a maneuvering target accurately. In recent years, the IMM (Interactive Multiple Model) algorithm has been proposed. The IMM is expected to reduce tracking errors for both non-maneuvering and maneuvering target. However, the IMM requires heavy computational burden, because it utilizes multiple Kalman filters in parallel. On the other hand, the α-β filter with an acceleration term which can estimate maneuver acceleration from the past target estimated positions using the kinetic model, has been proposed. This filter is not available for tracking targets under clutter environment, since it does not calculate the covariance matrix which is needed for gate setting. In this paper, we apply the acceleration estimate to the Kalman filter, and propose the hybrid Kalman filter with a constant-velocity filter and an acceleration estimation filter, and it integrates the outputs of two filters using the normalized distance of the prediction error of each filter. The computational requirement of the proposed filter is smaller than that of the IMM since the proposed filter consists of only two Kalman based filters. The proposed method can prevent deteriorating tracking accuracy by reducing the risk of maneuver misdetection when a target maneuvers. We evaluate the performance of the proposed filter by computer simulation, and show the effectiveness of the proposed filter, comparing with the conventional Kalman filter and the two-stage Kalman filter.

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.

Knudsen et al. proposed an efficient method based on a tree-search algorithm with recursive process for reconstructing the internal state of RC4 stream cipher. However, the method becomes infeasible for word size n > 5 because its time complexity to reconstruct the internal state is too large. This letter proposes a more efficient method than theirs. Our method can reconstruct the internal state by using the pre-known internal-state entries, which are fewer than their method.

The general public is expected to demand in not too distant future instituting more stringent certification procedures for computing parts of traditional and new-generation safety-critical application systems. Such quality-of-service (QoS) certification processes will not and can not rely solely on the testing approach. Design-time guaranteeing of timely service capabilities of various subsystems is an inevitable part of such processes. Although some promising developments in this area have been occurring in recent years, the technological challenges yet to be overcome are enormous. This paper is a summary of the author's perspective on the remaining challenges and promising directions for tackling them.

In this paper, the time-frequency separation algorithm (TFS) proposed by Belouchrani and Amin is applied to ground penetrating radar (GPR) data to reduce ground clutter, that hides reflected waves from a near-surface planar interface. We formulated the problem with several assumptions so that narrow band signals, whose center frequency and baseband signal depend on propagation paths, are received at the receiver, when a wideband signal is radiated from a transmitter. These phenomena can be clearly seen in time-frequency distribution (TFD) of the received signal. In this paper, we adopted the TFS utilizing the TFD signature as a blind separation technique to separate the ground clutter from the target signals. We show numerical and experimental results in order to verify the validity of the problem formulation and the TFS. We carried out GPR measurements to measure permafrost in Yakutsk, Russia. We found the difference in TFD signatures between the ground clutter and the target signal in the experimental data. We could detect the upper boundary of the permafrost with the TFS in spite of the unstable ground clutter.

We have demonstrated AlGaN/GaN high electron mobility transistors (HEMTs) grown on epitaxial AlN/sapphire templates. The crystal qualities and fabricated device performances between AlGaN/GaN HEMTs on epitaxial AlN/sapphire templates and conventional AlGaN/GaN HEMTs on sapphire substrates with low-temperature buffer layer (LT-BLs) are compared with each other. By using epitaxial AlN/sapphire templates instead of LT-BLs, higher mobility was exhibited and superior crystal qualities were observed, as confirmed by X-ray diffraction (XRD), atomic force microscopy (AFM) images and capacitance-voltage measurements. In addition, the dc characteristics of the fabricated devices on epitaxial AlN/sapphire templates were enhanced. AlGaN/GaN HEMTs on epitaxial AlN/sapphire templates are promising candidates for practical applications of nitride-based electronic devices.

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.

We report for the first time the design, process and characterization of InP-based micrometer emitter InGaAlAs/GaAsSb/InP Double HBTs (DHBTs) and their microwave performance. The layer structure not only allows the implementation of InP collector free of current blocking, but also enables small turn-on voltage and ballistic launching of electrons due to the positive conduction band discontinuity of emitter to base. The DHBT structure was grown on nominal (001) InP substrates using MBE. Solid Si and CBr4 gas were used for n-type and p-type doing respectively. Fabricated large DHBTs showed high DC gain (> 80), small turn-on voltage 0.62 V, almost zero offset voltage, and nearly ideal base and collector current characteristics (ideality factors 1.0 for both B-E and B-C junctions). Small DHBTs demonstrated VCEO > 8 V and stable operation at high current density exceeding 100 kA/cm2. Maximum fT of 57 GHz and maximum fmax of 66 GHz were achieved from 1 20 µm2 devices at similar bias condition: JC = 8.0 104 A/cm2 and VCE =3.5 V. The InGaAlAs/GaAsSb/InP DHBTs appear to be a very promising HBT solution having simultaneous excellent RF and DC performances.

In this paper, we introduce a flexible design for intellectual property(IP) which has become important to design system LSI. The proposed IPs which have high flexibility for user requirement. The design priority is determined by setting parameters as the number of arithmetic unit, internal bitlength, clock speed and so on. The design time can thus be reduced. Designed IP is based on the reconfigurable architecture in which many structures can be dynamically selected. This paper shows a implementation of Frequency Response Masking digital filter(FRM) and Principal Components Analysis(PCA) using a reconfigurable architecture. We show the method to realize the designed circuit and the results of experiments using field programmable gate array(FPGA).

In this letter, we propose (1) a new sub-optimum minimum distance search (sub-MDS), whose search complexity is reduced considerably compared with optimum MDSs and (2) a termination criterion, called near optimality condition, to reduce the average number of decoding iterations with little degradation of error performance for the proposed decoding using sub-MDS iteratively. Consequently, the decoding algorithm can be applied to longer codes with feasible complexity. Simulation results for several Reed-Muller (RM) codes of lengths 256 and 512 are given.

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.

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.

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.

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.