A blue-light-emitting Eu2+ doped CaMgSi2O6 phosphor with a long lifetime for a plasma display panel (PDP) was developed. The CaMgSi2O6:Eu2+(CMS:Eu2+) phosphors synthesized using SiO2-rich source materials show no luminance degradation during the baking process for binder burn-off, and the photoluminescence peak intensity of the Eu2+ emission band is higher than that of conventional blue phosphor BaMgAl10O17:Eu2+ (BAM) after the baking process. The test PDP using synthesized CMS:Eu2+ phosphor shows a comparable emission peak intensity to that of BAM, while the luminance of the CMS:Eu2+ panel is approximately 55% that of the BAM panel due to the narrower spectral bandwidth and shorter peak wavelength. The CMS:Eu2+ panel shows less luminance degradation than BAM under the aging test, and the CMS:Eu2+ panel retains 85% of its luminance after 300 hours driving. It is found that CMS:Eu2+ appears to be a promising blue phosphor material for PDP.

To investigate the feasibility of a compact FEA image sensor with a large number of pixels, a 128 96 pixel FEA image sensor with a 4-µm-thick HARP target was fabricated and tested for the first time. The experimental results showed that the prototype could stably operate as a highly sensitive image sensor having both sufficient resolution corresponding to the number of pixels and a wide dynamic range, which demonstrated its potential as a next-generation image sensor.

A siphon-trap of a Petri net N is defined as a place set S with S = S, where S = { u| N has an edge from u to a vertex of S} and S = { v| N has an edge from a vertex of S to v}. A minimal siphon-trap is a siphon-trap such that any proper subset is not a siphon-trap. The following polynomial-time algorithms are proposed: (1) FDST for finding, if any, a minimal siphon-trap or even a maximal class of mutually disjoint minimal siphon-traps of a given Petri net; (2) FDSTi that repeats FDST i times in order to extract more minimal siphon-traps than FDST. (3) STFM_T (STFM_Ti, respectively) which is a combination of the Fourier-Motzkin method and FDST (FDSTi) and which has high possibility of finding, if any, at least one minimal-support nonnegative integer invariant.

This letter presents text-independent speaker identification results for telephone speech. A speaker identification system based on Karhunen-Loeve transform (KLT) derived from codebook design using genetic algorithm (GA) is proposed. We have combined genetic algorithm (GA) and the vector quantization (VQ) algorithm to avoid typical local minima for speaker data compression. Identification accuracies of 91% were achieved for 100 Mandarin speakers.

In this paper, we consider a flexible method for designing n-entities communication protocols and services. The proposed technique considers alternative and parallel composition of n service specifications and n protocol specifications, where n 2. The specifications are specified in Basic LOTOS which is a Formal Description Technique (FDT). We use the weak bisimulation equivalence () to represent the correctness properties between the service specification and the protocol specification.

Low-temperature poly-Si thin film transistor with gate-overlapped LDD (GOLD) structure was fabricated. Reliability was evaluated using electrical stress method comparing conventional LDD and single drain structures. As previous researchers have reported, we have confirmed that the degradation of ON current and the field effect mobility was very small compared to conventional LDD or non-LDD structures. We have analyzed the reliability of the GOLD TFT using two-dimensional device simulator. We have clarified that vertical negative field plays a dominant role for improving the reliability in the GOLD TFT. Impact ionization occurs far from the interface between the oxide and poly-silicon by the vertical negative field. GOLD structure is promising for the realization of system on panel.

We propose a novel three-dimensional (3-D) display using only two 2-D images displayed at different depths. It is based on a new perceptual phenomenon induced by the human binocular visual system and enables an observer using no extra equipment to perceive an apparent 3-D image of continuous depth when the luminance is divided between the 2-D images according to the 3-D image depth. Our prototype direct-vision 3-D display using this mechanism can easily produce moving 3-D color images by using conventional 2-D color displays.

This paper presents a multiple-valued logic-in-memory circuit with real-time programmability. The basic component, in which a dynamic storage function and a multiple-valued threshold function are merged, is implemented compactly by using charge storage and capacitive coupling with a DRAM-cell-based circuit structure under a 0.8-µm CMOS technology. The pass-transistor network using these basic components makes it possible to realize any multiple-valued-inputs binary-outputs logic circuits compactly. As a typical example, a fully parallel multiple-valued magnitude comparator is also implemented by using the proposed DRAM-cell-based pass-transistor network. Its execution time and power dissipation are reduced to about 11 percent and 29 percent, respectively, in comparison with those of a corresponding binary implementation. A prototype chip is also fabricated to confirm the basic operation of the proposed DRAM-cell-based logic-in-memory circuit.

In recent years, the domino logic has received much attention as a design technique of high-speed circuits. However, in the case of standard domino logic, only non-inverting functions are allowed. Then, the clock-delayed (CD) domino logic that provides any logic function is proposed in order to overcome such domino's drawback. In addition, domino circuits are more sensitive to circuit noise compared with static CMOS circuits. In particular, crosstalk causes critical problems. Therefore, we focus our attention on crosstalk faults in CD domino circuits. However, in CD domino circuits, there are faults that don't propagate faulty values to any primary output even though crosstalk pulses are generated. Then, we remove such faults from the target fault list by considering structures of CD domino circuits, and perform a fault simulation for the reduced target fault list using two kinds of fault simulation method together. We realize CD domino circuits in VHDL and perform the proposed fault simulation for the combinational part of some benchmark circuits of ISCAS'89 on a VHDL simulator. Fault coverage for random vectors was obtained for s27 to s1494 under the limitation of simulation time.

A procedure to remove redundancies in sequential circuits is proposed using strongly unreachable states, which are the states with no incoming transitions. Test generation is used to find undetectable faults related to two or more strongly unreachable states. Experimental results show the new procedure can find more redundancies of sequential circuits.

We present an efficiency improvement on an existing unlinkable divisible e-cash system. In the based e-cash system, an e-coin can be divided to spent, and thus the exact payments are available. Furthermore, to protect customer's privacy, the system also satisfies the unlinkability in all the payments, which is not satisfied in other existing divisible e-cash systems. The unlinkability means the infeasibility of determining whether two payments are made by the same customer. However, in the unlinkable divisible e-cash system, the payment protocol needs O(N) computations, and thus inefficient, where N indicates the divisibility precision. For example, in case of N=100,000, about 200,000 exponentiations are needed for the worst. We improve the payment protocol using the tree approach. In case of N=100,000, the protocol with our improvement needs only about 600 exponentiations for the worst. This good result can be obtained for other N which is more than about 100.

Emerging requirement for higher rate data services and better spectrum efficiency is the main driving force identified for the third generation mobile radio systems. Moreover, it needs the capability of providing predictable qualities of service (QoS) for different applications. To maintain different QoS requirements, mechanisms such as call admission control (CAC) and load control, etc. are needed to achieve the required services. In this paper, we propose a CAC algorithm based on channel assignment in a multi-chip rate direct-sequence CDMA (MCR-DS-CDMA) cellular system supporting multi-rate services. Five multi-MBC (mapping of information bit rates to chip rates) channel assignment schemes and corresponding channel selection rules are proposed herein. Computer simulation, where multimedia applications are considered, is used to evaluate the system performance (e.g., blocking probability and system capacity) with different channel assignment schemes. Numerical results demonstrate that scheme 5 (i.e., Minimum-influence scheme) performs better because it provides the highest system capacity and least blocking probability.

As technology moves to 600-1000 Gb/sq-in areal densities and deep sub-10 nm head-disk spacing, it is of crucial importance to prevent both the conventionally defined thermal decay and the tribologically induced decay of recorded magnetic signal. This paper reports a novel method for recording and visualizing the signature of the potential tribological decay. The details of the methodology, its working principles, and typical results obtained are presented in this work. The method is based on the introduction of a type of visualizing disks which use a layer of magneto-optical material with low Curie temperature to replace the magnetic layer used in the conventional magnetic media. The method and corresponding setup were used successfully in the visualization of potential decay caused by slider-particle-disk contact, slider-disk contact during track seeking operations, and slider-disk impact during loading and unloading operations.

An information retrieval model that intends to conceptually deal with the documents in the Internet is proposed. The first half of this model is a stage to select the documents, which may meet the user's long-term interests, by employing a filtering or retrieval system. The latter half is a stage for linear document arrangement and for adjacent cluster based browsing. For the document collection filtered out, similarity matrices are computed and then the documents are arranged such that the highly similar ones are adjacently placed. By this treatment the documents are considered to form the clusters, some of which are adjacently placed when they include similar documents. A user can satisfy her/his needs by first browsing in the clusters containing documents highly similar to a query, and next by extending the browsing process into the clusters adjacent to the ones just examined. In the adjacent clusters the documents having no keywords common to but conceptually related to the query can be found. Computational and statistical evaluations were done on two standard test collections. A virtual space navigator is also designed by using JAVA to assist a user in the browsing task.

In conventional Web Geographic Information System (GIS), there are serious drawbacks of high waiting time and low accessibility because the subsequent query has to wait until all the spatial data has been completely transmitted. In addressing these problems, this paper proposes a progressive transmission method which can reduce waiting time and increase accessibility. The proposed method has the following steps. First, significant vertices of geographic objects are selected into based on an algorithm, Priority_Order_Estimation (POE). Second, the selected vertices are inserted the data structure, Priority_Order_Queue (POQ). This allows a client to view, to request and occasionally to reject spatial data, rather than waiting for the whole map to arrive. Third, the transmission steps are processed progressively, where significant vertices of POQ are sent from server to client one by one. In the final step, if necessary, the entire spatial data set of SENDOBJSP, which is a transmission structure, is transmitted so that the original map is accurately displayed. The performance of the system proposed here has been evaluated according to the factors such as system response time and client storage space. For the comparisons, the total transmission method, layer transmission method and the proposed four-step transmission method were used. Compared with the conventional Web-based GIS, the system response time is twenty-two percent shorter and client storage space is reduced by about twenty-one percent. As a result, performance improvement, fast response time and less client storage usage, is achieved. Therefore, the proposed method can make a significant contribution in support of Web-based Vector GIS applications such as Environmental Management, Map On Demand Service and Assessment and Planning System.

This paper deals with formal verification of high-level designs, in particular, symbolic comparison of register-transfer-level descriptions and behavioral descriptions. We use state machines extended by quantifier-free first-order logic with equality, as models of those descriptions. We cannot adopt the classical notion of equivalence for state machines, because the signals in the corresponding outputs of such two descriptions do not change in the same way. This paper defines a new notion of consistency based on signal-transitions of the corresponding outputs, and proposes an algorithm for checking consistency of those descriptions, up to a limited number of steps from initial states. As an example of high-level designs, we take a simple hardware/software codesign. A C program for digital signal processing called PARCOR filter was compared with its corresponding design given as a register-transfer-level description, which is composed of a VLIW architecture and assembly code. Since this example terminates within approximately 4500 steps, symbolic exploration of a finite number of steps is sufficient to verify the descriptions. Our prototype verifier succeeded in the verification of this example in 31 minutes.

Metal particulate tape is one of the most advanced tape media to offer excellent performance at high recording densities. An accurate micromagnetic model of the metal particulate tape has been developed to analyze the magnetic properties of MP tapes. Both particle size distributions and orientation distribution are included in the model, and the magnetostatic interactions among particles are accurately calculated with the shape of ellipsoids. A partial mean field approximation applied in the calculation is proved to be effective by M-H loop analysis.

As two simple relaxation oscillators are coupled by periodical and instantaneous switching, the system exhibits rich superstable synchronous phenomena. In order to analyze the phenomena, we derive a hybrid return map of real and binary variables; and give theoretical results for (1) superstability of the synchronous phenomena and (2) period of the synchronous phenomena as a function of the parameters. Using a simple test circuit, typical phenomena are verified in the laboratory.

This paper presents an architecture for a table-lookup (TLU) engine that allows the real-time operation of complicated TLU for telecommunications, such as the longest prefix match (LPM) and the long-bit match in packet classification. The engine consists of many CAM (Content Addressable Memory) chips, which are classified into several groups. When actual TLU is performed, the entries in each CAM group are searched simultaneously, and the best entry candidate in each group is selected by an intra-group arbiter. The final output, the entry desired, is decided by an inter group arbiter that selects one group. This hierarchical structure of arbitration is the key to the scalability of the engine. To accelerate the operation speed of the engine, we introduce a novel mechanism called "hit-flag look-ahead" that sends a hit-flag signal from each matched CAM chip to the inter group arbiter before each intra group arbiter calculates the best CAM output in the group. We show that a TLU engine based on the above architecture achieves significantly fast performance compared to engines based on conventional techniques, especially in the case of a large number of entries with long-bit matching. Furthermore, our architecture can realize an 33.3 Mlps (lookups per second) within a 128 bit 300,000-entry table at wire speed.

Face detection from cluttered images is very challenging due to the wide variety of faces and the complexity of image backgrounds. In this paper, we propose a neural network based approach for locating frontal views of human faces in cluttered images. We use a radial basis function network (RBFN) for separation of face and non-face patterns, and the complexity of RBFN is reduced by principal component analysis (PCA). The influence of the number of hidden units and the configuration of basis functions on the detection performance was investigated. To further improve the performance, we integrate the distance from feature subspace into the RBFN. The proposed method has achieved high detection rate and low false positive rate on testing a large number of images.