A new fuzzy logic-based buffer management scheme (BMS) called fuzzy early detection (FED) is presented to improve transmission control protocol (TCP) performance over the unspecified bit rate (UBR) service of asynchronous transfer mode (ATM) networks. FED uses early congestion detection and selective packet discard (ECD/SPD) strategies to achieve its design goals, and adopts early packet discard (EPD) to prevent frequent buffer overflows. Two variants of FED are constructed for comparison purposes. FED performance is then evaluated against those of its variants, pure EPD and P-random early detection (P-RED) through various simulations. The effects of TCP implementation, TCP maximum segment size (MSS), network's propagation delay (PD) and switch buffer size (SBS) on their performances are studied. The overall result shows that FED is superior to the other BMSs when the criteria of efficiency, fairness, scalability and switch buffer requirement are considered collectively.

Fully embedded spiral inductors in a low loss dielectric multi-layer were designed and fabricated using a low temperature co-fired ceramics (LTCC) technology for RF SIP (system in package) integrations. The line width/space and the number of spiral layers were optimized within five layers of LTCC dielectric for high Q-factor, high self-resonant frequency (SRF), process easiness, and compact size. The embedded multi-layer spiral inductors reveal better performance in terms of Q-factor, SRF and the effective inductance Leff than planar spiral inductors of the same dimension and number of turns. The optimized multi-layer spiral inductor shows maximum Q of 56, Leff of 6.6 nH at Qmax and SRF of 3.6 GHz while planar spiral inductors have maximum Q of 49, Leff of 5.8 nH at Qmax and SRF of 3.0 GHz.

Sliding contact behavior is important in the mechanism of collecting current. In this study, the effect of ambient gas including an inert gas on surface film formation and on the contact voltage drop was examined, changing the atmosphere from low pressure to atmospheric pressure. Furthermore, the sliding surface state was observed using SEM, EDX and XPS analyzers after the test operation. As a result, at the sliding contact in an inert gaseous environment (nitrogen and argon), it was confirmed that the contact voltage drop tends to increase. However, it was clarified that any chemically generated surface film is difficult to detect in the inert gas environment by qualitative analysis. On the basis of these results, we suggest the existence of physically adsorbed surface film. The relationship between inert gases and sliding contact phenomena is discussed.

In transient analyzing of a crosstalk, the crosstalk waveform can be obtained with a commercial simulator such as SPICE simulation or FDTD (Finite Difference Time Domain) simulation. In case of using a simple model, a CMOS-IC load is considered as a constant capacitance load in crosstalk simulation. However, the semiconductor devices, such as CMOS-IC, have a characteristic of nonlinear impedance depending on the input voltage. We measured the far-end crosstalk of two parallel microstrip lines for a CMOS inverter (74HC04) load by changing the magnitude of the input step voltage. As the result, we found that the far-end crosstalk for the CMOS inverter load dose not necessarily depend on the input capacitance of the CMOS inverter.

This paper presents a review of volumetric erosion studies applied to electrical contacts. The numerical methods presented are generic and could equally be applied to a number of areas where surfaces have been eroded or damaged. Equally there is no scale limitation of the surfaces to which the numerical methods can be applied. The paper starts with an introduction of the issues associated with the measurement of contact erosion, and then presents a summary of various hardware system for making 3D measurements of surfaces such as electrical contacts. This is followed by a review of the generic form fitting methods and also volume calculation methods. The paper concludes with a review of results taken from a test system for contact studies and from contact samples taken from commercial relays.

We are concerned with semantic views on an extended version of SLD resolution with negation as failure (SLDNF resolution) for normal logic programs, which Eshghi and Kowalski (1989) presented by making the SLDNF resolution capable of keeping negated predicates in memory and of extracting abducible predicates. This paper deals with its formal representation in relational form, for the purpose of interpreting the normal goal as an acquisitor of negated predicates stored in memory. Some set acquired by the derivations which the normal goal evokes is defined to be a semantics of the goal, under the constraint that the set is as large as possible and does not violate consistency in model theory. The semantics is discussed with relation to the 3-valued logic model theory, where the model theory is represented by alternating fixpoint semantics (Van Gelder, 1993). For simplicity of treatment, this paper is concerned with the normal logic program in the propositional logic.

A Fair Queueing Algorithm is proposed for data services in an integrated voice/data CDMA system. We introduce short-term and long-term fairness concepts to allocate data users fairly. Using these concepts, we propose a Weighted Fair Queueing with Status Control (WFQS) in the consideration of a Generalized Processor Sharing (GPS) fluid-flow model. This proposed scheme allocates resources using channel status information. The throughput and delay of data users could be improved when this scheme is applied to wireless channels.

We define a d-matched digraph and propose a recursive procedure for designing an optimal d-matched digraph without bidirectional edges. The digraph represents an optimal highly structured system which is a special class of self-diagnosable systems and identifies all of the faulty units independently and locally in O(|E|) time complexity. The procedure is straightforward and gives a system flexible in network connections. Hence the procedure is applicable to real systems such as the Internet or cooperative robotic systems which change their topology dynamically.

Micali and Rivest have proposed a transitive signature scheme for an undirected graph, which is suitable for signing data with undirected graph structure. The problem of finding a transitive signature scheme for a directed graph has remained an open problem. In this paper, we propose a transitive signature scheme for a directed tree. Since the directed tree is a special case of the directed graph, the proposed scheme is a partial solution for the open problem. We also show that a transitive signature scheme for the undirected graph can be constructed from a bundling homomorphism. This means that the transitive signature scheme for the undirected graph is closely related with a fail-stop signature scheme.

The power dissipation tolerances for InP/ InGaAs uni-travelling-carrier photodiodes (UTC-PDs) and pin-PDs under high power optical inputs are compared. Catastrophic failures occur at constant power dissipations of 240 and 160mW for the UTC-PDs and pin-PDs, respectively. Scanning electron microscope observations confirm that the areas of destruction are located in the high electric-field region in the depletion layer.

A reconfigurable network interface called RHiNET-2/NI0 is developed for parallel processing of PCs distributed within one or more floors of a building. Two configurations: the HS (High Speed) configuration with only a high-speed primitive and the DSM (Distributed Shared Memory) configuration which supports sophisticated primitives can be selected by the network requirement. From the empirical evaluation, it appears that the HS configuration markedly improves the latency of data transfer compared with traditional network interfaces. On the other hand, the DSM configuration executes sophisticated primitives for distributed shared memory more than twice as fast as that of software implementation.

Obtaining a linearizing feedback and a coordinate transformation map is very difficult, even though the system is feedback linearizable. It is known that finding a desired transformation map and feedback is equivalent to finding an integrating factor for an annihilating one-form for single input nonlinear systems. It is also known that such an integrating factor can be approximated using the simple C.I.R method and tensor product splines. In this paper, it is shown that m integrating factors can always be approximated whenever a nonlinear system with m inputs is feedback linearizable. Next, m zero-forms can be constructed by utilizing these m integrating factors and the same methodology in the single input case. Hence, the coordinate transformation map is obtained.

In this paper, we propose a new transmitter diversity. We propose a combined system with path diversity gain of the distributed antennas and frequency diversity gain of the multi-carrier. The proposed system transmits different data using several sub-carriers which are correlated, while, transmitting the same data using several sub-carriers which are decorrelated. It can achieve combined path and frequency diversity in a variable frequency selective fading channel. It provides high data rate services by transmitting the different data using each correlated carrier, and supports good quality by transmitting the same data on decorrelated carriers using multiple antennas. The proposed system is applicable to multimedia service and can achieve high quality according to channel condition. Thus, the proposed system is sufficiently flexible enough to very support a variety of video, image, voice and data services at a high level of quality.

Partial face images, e.g., eyes, nose, and ear images are significant for face recognition. In this paper, we present a method for partial face extraction and recognition based on Radial Basis Function (RBF) networks. Focus has been centered on using ear images because they are not influenced by facial expression, and the influences of aging are negligible. Original human side face image with 320240 pixels is input, and then the RBF network locates the ear and extracts it with a 200120 pixel image. Next, another RBF network is constructed for the purpose of recognition. An algorithm that determines the radius of an RBF function is proposed. Dynamic radius, so called as compared to static one, is found through the algorithm that makes RBF functions adaptable to the training samples. We built a database that contains 600 side face images, from 100 people, to test the method and the results of both extraction and recognition are satisfied.

This paper studies the necessity of local CFAR processing in CFAR detection with multisensors. This necessity is shown by comparison between centralized CFAR detection and the distributed CFAR detection scheme based on local CFAR processing, under three typical backgrounds and in several cases of mismatching ρ, the relative ratio of local clutter power level in sensors in a homogeneous background. Results show that centralized CFAR processing can not be considered as CFAR without exact prior knowledge of ρ. In addition, even if the knowledge of ρ is available, the great difference among local clutter power levels can also result in severe performance degradation of centralized CFAR processing. In contrast, the distributed CFAR detection based on local CFAR processing is not affected by ρ at all, a fact which was proposed in a previous published paper. Therefore, the CFAR processing must be made locally in sensors for CFAR detection with multisensors.

TCP/IP is a key technology in the next generation mobile communication networks. A significant amount of wireless traffic will be carried in the Internet, and wireless connections will have to share network resources with wired connections. However, in a wireless network environment, TCP suffers significant throughput degradation due to the lossy characteristic of a wireless link. Therefore, to design the next generation mobile networks, it is necessary to know how much the wireless connection suffers from the degradation in comparison to the wired connection. In this paper, we discuss the fairness issue between TCP connections over wireless and wired links, and theoretically analyze the fairness of throughput between TCP over wireless link with ARQ (Automatic Repeat reQuest)-based link layer error recovery and TCP over error-free wired link. We validate our analysis by comparing the numerical results obtained from the analysis with the results obtained from computer simulation. The numerical results show that the fairness is sensitive to network propagation delay and variation rapidity of wireless link characteristic. We also obtain the theoretical lower bound of fairness.

The Neural Network (NN) is applied to recognize basic PCB configurations using its magnetic near-field spectra and radiated far-field emission. The learning process is accomplished by using the computed spectra of the radiated field from PCBs having different configurations. The anomaly is detected through the monitoring of the spectra's amplitude frequency by injecting a voltage pulse at the PCB configuration. The trained NN is then applied to the identification of PCB layouts from radiated emission measurements. The trained NN can identify all of those PCB configurations from the magnetic near-field spectra and the radiated far-field EMI. Moreover, the calculated results of the NN are compared with the actual far-field measurements and other models for evaluation. Finally, the NN used for predicting far-field emission from their magnetic near-field measurement is proposed. Experiments show that the NN can predict the far-field spectra from the magnetic near-field spectra.

In fast frequency hopped (FFH) non-coherent MFSK systems, the diversity combining scheme can be used effectively in order to combat the interference, especially jamming noise. In this paper, we simulate and discuss the BER performance of FH/MFSK system for different diversity combining schemes, such as linear combining, clipped-linear combining, normalized envelop detection (NED), order statistics (OS) NED and product combining receiver (PCR), in the presence of both the worst case partial band jamming (PBJ) and the fading channel. The performances of those combining schemes except for linear combining are similar each other in the worst case PBJ without the fading. In the existence of both the worst case PBJ and the fading channel, the clipped-linear combining scheme suffers a larger drop in performance than other combining schemes. It is noteworthy that the performances of OSNED and PCR are the best in Rayleigh fading channel among those combining schemes.

A novel postprocessing algorithm for reducing the blocking artifacts in block-based coded images is proposed using block classification and adaptive multi-layer perceptron (MLP). This algorithm is exploited the nonlinearity property of the neural network learning algorithm to reduce the blocking artifacts more accurately. In this algorithm, each block is classified into four classes; smooth, horizontal edge, vertical edge, and complex blocks, based on the characteristic of their discrete cosine transform (DCT) coefficients. Thereafter, according to the class information of the neighborhood block, adaptive neural network filters (NNF) are then applied to the horizontal and vertical block boundaries. That is, for each class a different two-layer NNF is used to remove the blocking artifacts. Experimental results show that the proposed algorithm produced better results than conventional algorithms both subjectively and objectively.

The present paper addresses the design of manufacturing systems. A resource planning and task allocation problem is proposed, and a multi-agent system for this problem is discussed. In the multi-agent system, an agent exists for each resource and for each operation. The proposed multi-agent system improves the quality of resulting plans by the learning of these agents.