Since a logic circuit often has too many paths to test delay of all paths, it is necessary for path delay testing to limit the number of paths to be tested. The paths to be tested should have large delay because such paths more likely cause a fault. Additionally, a test set for the paths are required to detect other models of faults as many as possible. In this paper, we investigate two typical criteria of path selection for path delay testing. From our experiments, we observe that test patterns for the longest paths cannot cover many local delay defects such as transition faults.

A packed SIMD type operation or a SIMD operation is n-parallel b/n-bit sub-operations executed by the modified n-bit functional unit. Such a functional unit is called a SIMD functional unit and a processor core which can execute SIMD operations is called a SIMD processor core. SIMD operations can be effectively applied to image processing applications. This paper focuses on hardware/software cosynthesis of SIMD processor cores and particularly proposes a new simulator generator which simulates pipelined instructions for a SIMD processor. Generally, a SIMD functional unit has many options and then we can have so many different SIMD functional unit instances. However, since our hardware/software cosynthesis system synthesizes a special-purpose processor core for an input application program, it uses very limited SIMD functional unit instances. In the proposed approach, we consider a SIMD operation to be a set of SIMD sub-operations. By adding up the appropriate SIMD sub-operations, we construct a single SIMD operation. Then a SIMD functional unit behavior can be characterized by a collection of SIMD operations. This approach has the advantage that: if we have a small number of behavior libraries for SIMD sub-operations, we can instantiate a particular SIMD functional unit behavior. Experimental results demonstrate the effectiveness of the proposed approach.

This paper presents a distinct approach to the robustness stability analysis and design of linear uncertain systems. Based on the extension version of the projection method, the specific stability issue, which ensures the poles within a specific region, can be efficiently analyzed. Furthermore, we derive a simple design scheme for a class of uncertain systems. By the proposed numerical algorithm, some examples are given to demonstrate the validity and effectiveness.

A two stage non-scan design for testability method is proposed. The first stage selects test points based on an earlier testability measure conflict. A new design for testability algorithm is proposed to select test points by a fault-oriented testability measure conflict+ in the second stage. Test points are selected in the second stage based on the hard faults after the initial ATPG run of the design for testability circuit in the preliminary stage. The new testability measure conflict+ based on conflict analysis of hard-faults in the process of test generation is introduced, which emulates most general features of sequential ATPG. The new testability measure reduces testability of a fault to the minimum D or controllability of the primary outputs, and therefore, does not need observability measure any more. Effective approximate schemes are adopted to get reasonable estimation of the testability measure. A couple of effective techniques are also adopted to accelerate the process of the proposed design for testability algorithm. Experimental results show that the proposed method gets even better results than two of the recent non-scan design for testability methods nscan and lcdft.

This paper presents a low-power implementation scheme of interpolation FIR filters using distributed arithmetic (DA). The key idea of the proposed scheme involves look-up tables generating only nonnegative values. Thus, the proposed scheme can minimize the dynamic power consumption of interpolation FIR filters using DA without additional hardware. When used for implementing a pulse shaping filter for CDMA2000 mobile stations, the proposed filter not only has almost the same hardware complexity as the conventional one; it also has approximately 43% reduced power consumption.

High-temperature stability of copper (Cu) gate AlGaN/GaN high electron mobility transistors (HEMTs) was investigated. Samples were annealed at various temperatures to monitor the changes on device performances. Current-voltage performance such as drain-source current, transconductance, threshold voltage and gate leakage current has no obvious degradation up to annealing temperature of 500 and time of 5 minutes. Also up to this temperature, no copper diffusion was found at the Cu and AlGaN interface by secondary ion mass spectrometry determination. At annealing temperature of 700 and time of 5 minutes, device performance was found to have degraded. Gate voltage swing increased and threshold voltage shifted due to Cu diffusion into AlGaN. These results indicate that the Schottky contact and device performance of Cu-gate AlGaN/GaN HEMT is stable up to annealing temperature of 500. Cu is a promising candidate as gate metallization for high-performance power AlGaN/GaN HEMTs.

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.

Digital rights management in client-server environments requires the establishment of client integrity, in order to protect sensitive (secret) information from loss or misuse. Clients are vulnerable to powerful man-in-the-middle attacks through malicious software (viruses, etc.), which is undetectable by conventional anti-virus technology. We present such powerful viruses and demonstrate their ability to compromise clients. Furthermore, we introduce a defense against all viruses, which is based on simple hardware devices that execute specialized protocols to establish client integrity and protect against sensitive data loss.

This paper investigates the stability problem of singular systems with saturation actuators. A Lyapunov method is employed to give the sufficient conditions for stability of closed-loop systems with saturation actuators. The controller is designed to satisfy the requirement for stability under the nonlinear saturation. In addition, a method is presented for estimating the domain of attraction of the origin.

Detecting the possibility of inference attacks is necessary in order to keep a database secure. Inference attacks mean that a user tries to infer the result of an unauthorized queries to the user. For method schemas, which are a formal model of object-oriented databases, it is known that the security problem against inference attacks is decidable in polynomial time in the size of a given database instance. However, when the database instance or authorization has slightly been updated, it is not desirable to check the entire database again for efficiency. In this paper, we propose several sufficient conditions for update operations to preserve the security. Furthermore, we show that some of the proposed sufficient conditions can be decided much more efficiently than the entire security check. Thus, the sufficient conditions are useful for incremental security checking.

We propose a frequency stabilization system for laser diodes (LDs), in which the electrical feedback loop response can be determined using an on-line genetic algorithm (GA) so as to attain lower LD frequency noise power within the specific Fourier frequency range of interest. At the initial stage of the stabilization, the feedback loop response has been controlled through GA, manipulating the proportional gain, integration time, and derivative time of conventional analog PID controller. Individuals having 12-bit chromosomes encoded by combinations of PID parameters have converged evolutionarily toward an optimal solution providing a suitable feedback loop response. A fitness function has been calculated for each individual in real time based on the power spectral density (PSD) of the frequency noise. The performance of this system has been tested by stabilizing a 50 mW visible LD. Long-term (τ > 0.01 s) frequency stability and its repeatability have been improved.

Complete complementary codes have the property that the sum of correlation functions of several sequences satisfies both ideal autocorrelation and cross-correlation values. Modulatable complete complementary codes (MCC codes), which is a type of periodic complete complementary codes, are suitable for spreading sequences of M-ary CDMA systems. In the present paper, we propose a new method for constructing MCC codes. Using this method, we can easily generate various MCC codes.

As head-disk spacing is reduced, the effects caused by inter-molecular level interactions between head-slider and disk media are becoming a severe stability concern of head-slider's positioning in both flying height and track following directions. Therefore, there is a need to explore simple but effective methods for characterizing two dimensional (2D) stability. Ideally methods should be easy to implement in both the laboratory and in the quality control of disk drive and component manufacturing. A reading process based in-situ method is explored in this work. The method is simple and can effectively reveal the 2D stability of the head-slider in both laboratory and manufacturing environments. The results obtained also suggest that the observable sway mode vibration of the suspension can be excited earlier than the air-bearing vibration mode, when the flying height is reduced.

In 1982, Buckles and Petry proposed fuzzy relational database for incorporating non-ideal or fuzzy information in a relational database. The fuzzy relational database relies on the specification of similarity relation in order to distinguish each scalar domain in the fuzzy database. These relations are reflexive, symmetric, and max-min transitive. In 1989, Shenoi and Melton extended the fuzzy relational database model of Buckles and Petry to deal with proximity relation for scalar domain. Since reflexivity and symmetry are the only constraints placed on proximity relations, proximity relation is considered as a generalization of similarity relation. However, we realized that naturally relation between fuzzy information is not symmetric. Here, we consider using conditional probability relation to represent similarity between two fuzzy data. Related to the properties of conditional probability relation, we introduce an interesting mathematical relation, called weak similarity relation, as generalization of similarity relation as well as proximity relation in which conditional probability relation is regarded as a concrete example of the weak similarity relation. In this paper, we propose design of fuzzy relational database to deal with conditional probability relation for scalar domain. These relations are reflexive and not symmetric. In addition, we define a notion of asymmetric redundant tuple based on two interpretations generalizing the concept of redundancy in classical relational database. In the relation to data querying, we discuss partitioning of domains with the objective of developing similarity class. Finally, we propose a new definition of partial fuzzy functional dependency (PFFD). Fuzzy functional dependency (FFD) as an extension of functional dependency (FD), usually used in design of fuzzy relational database, can be generated by the PFFD. Inference rules that are similar to Armstrong's Axioms for the FFD are both sound and complete.

An IP (Internet Protocol) over WDM network is expected to be an infrastructure for the next-generation Internet by directly carrying IP packets on the WDM-based network. Among several architectures for IP over WDM networks, one promising way is to overlay a logical topology consisting of lightpaths over the physical WDM network so that IP packets are carried on the lightpaths. The conventional methods for designing the logical topology have been focusing on maximizing throughput of the traffic. However, when the WDM network is applied to IP, the end-to-end path provided by the logical topology of the WDM network is not suitable to IP since IP has its own metrics for route selection. In this paper, we propose a new heuristic algorithm to design a logical topology by considering the delay between nodes as an objective metric. This algorithm uses a non-bifurcated flow deviation to obtain a set of routes that IP packets are expected to traverse. Our proposal is then compared with conventional methods in terms of the average packet delays and throughput. It is shown that our method becomes effective when the number of wavelengths is a limited resource.

This paper proposes a method to integrate computer specifications retrieved from multiple Web sites, to extract characteristic-data of each computer based on integrated information, and to present products suitable for a user's request. The specifications written in HTML are converted into normal forms called table structure. The quantitative attributes such as speed, capacity and dimensions are extracted by comparing them with the mean or mode of all sample data, and the qualitative ones such as kind of processor and graphics chip are extracted using knowledge provided manually. The recommended products are dynamically determined from the extracted data by a user's request and relevance feedback. Experimental results show the effectiveness of our method.

In this paper, we propose an efficient IP-Level power model with a small lookup table for complex CMOS circuits. The table has only one dimension that maps the zero-delay charging and discharging capacitance (CDC) into the real power consumption of pattern pairs but still has high accuracy. In order to reduce the table size, we collect those pattern pairs with similar CDC values to be a group and only set an entry in the lookup table for each group. The proposed dynamic grouping process can automatically increase the entries of the lookup tables to cover the current CDC distribution of designs during the power characterization process. In order to improve the efficiency of characterization process, the Monte Carlo approach is used during the estimation for the average power of each group to skip the samples that will not increase the accuracy too much. After the power model of a circuit is built, the average power consumption for any test sequence can be estimated easily. The experimental result shows that the table sizes are only up to 107 entries for ISCAS'85 benchmark circuits and the estimation error is only 2.99% on average using this lookup table.

We can easily access a remote database as well as a local database with HTML forms. Although implementing a database application with HTML forms is much simpler than implementing it with a proprietary graphical user-interface system, HTML forms and CGI programs still must be coded. We implemented a software tool that automatically generates the SQL statements that create a database for an application, the forms that are used as a user interface, and the Java servlets that retrieve the data requested through the forms. The database tables to be created and the forms to be generated are determined by the class diagram for the application. Our software tool, which we call WebSiteGen, thus simplifies the implementation of a Web-based database application.

This paper presents a modified microwave radio-thermometer (MRTM) with material characteristic estimator and multiple temperature conversion tables to measure subcutaneous temperature of a living body. This estimator provides a temperature retrieval unit with material characteristics such as permittivity, conductivity, thickness and geometry of the living body. The temperature retrieval unit with multiple temperature conversion tables can select one of the tables and compute temperature value corresponding to measured radiation power. In the experiments, it was shown that the radio-thermometer could reduce measurement errors of about 0.82 to 7.68 for the cases of distilled water and mixed liquid # 5 with thickness of 29.5 cm and 9.5 cm at the temperature of 37.

This paper introduces a design for testability (DFT) scheme for delay faults of a controller-data path circuit. The scheme makes use of both scan and non-scan techniques. First, the data path is transformed into a hierarchically two-pattern testable (HTPT) data path based on a non-scan approach. Then an enhanced scan (ES) chain is inserted on the control lines and the status lines. The ES chain is extended via the state register of the controller. If necessary, the data path is further modified. Then a test controller is designed and integrated to the circuit. Our approach is mostly based on path delay fault model. However the multiplexer (MUX) select lines and register load lines are tested as register transfer level (RTL) segments. For a given circuit, the area overhead incurred by our scheme decreases substantially with the increase in bit-width of the data path of the circuit. The proposed scheme supports hierarchical test generation and can achieve fault coverage similar to that of the ES approach.