In this paper, we propose a new fair queueing algorithm to improve cell delay variation (CDV) for real-time service categories and to make efficient use of system resources for multimedia traffic in high speed ATM networks. The proposed algorithm is called the delay variation-based fair queueing (DVFQ) algorithm, which is based on per-VC queueing to improve CDV and fairness for each VC of real-time services such as CBR and rt-VBR. In DVFQ algorithm, we define two fairness indexes, which indicate the degree of the fairness of CDV at the rate of each VC, and the degree of impartially sharing the bandwidth between the scheduled cells for each VC. The simulation results for both heavily and lightly loaded conditions show that DVFQ algorithm provides better performances in terms of the CDV, the CDV fairness, and the service fairness than those of FCFS for real-time service.

A Multiwavelength Brillouin/Erbium fibre laser which operates in long-wavelength band (L-band) is demonstrated with an approximate comb spacing of 10 GHz. The laser configuration consists of a long EDF to enable the L-band amplification and two 3-dB couplers to take a portion of the generated BEFL signal and re-inject it into the SMF to seed a cascaded BEFL line in the same direction as the first BEFL line. 20 lines including the anti-Stokes are obtained with the maximum Brillouin pump and 980 nm-pump power of 8.9 mW and 92 mW, respectively.

In order to clarify the receiver sensitivity of remote keyless entry systems operating at 314 MHz, the radiation characteristics of a cabin antennas must be studied. For this purpose, electromagnetic simulations are very useful but the multiple reflected waves present in the cabin must be accurately estimated. No prior study examined the radiation characteristics of cabin antennas. This paper introduces an accurate simulation method. A MM (Method of Moments) simulator is selected because it can simulate multiple reflected waves. Initial studies are being performed to find the calculation requirements and ensuring convergence of multiple reflected wave structures. Next, calculation requirements for car analyses such as convergence parameters and computer abilities are studied. The calculation time is 11 hours by a personal computer. 1.1 GB of RAM is also needed. Many calculated results such as three-dimensional radiation patterns and induced currents on the car's body are obtained. The radiation pattern varies with antenna position, and polarization changes are shown. In order to ensure that the results are accurate, measurements are made on a one seventh scale model of a car. The good agreement of measured and calculated results verifies the validity of the simulation method. The influence of multiple reflected waves on the radiation patterns is also experimentally studied. The conclusion is that the MM method is shown to be useful in estimating the radiation pattern of cabin antennas. Interesting calculation results are also shown.

In this paper, we propose topic extraction models based on statistical relevance scores between topic words and words in articles, and report results obtained in topic extraction experiments using continuous speech recognition for Japanese broadcast news utterances. We attempt to represent a topic of news speech using a combination of multiple topic words, which are important words in the news article or words relevant to the news. We assume a topic of news is represented by a combination of words. We statistically model mapping from words in an article to topic words. Using the mapping, the topic extraction model can extract topic words even if they do not appear in the article. We train a topic extraction model capable of computing the degree of relevance between a topic word and a word in an article by using newspaper text covering a five-year period. The degree of relevance between those words is calculated based on measures such as mutual information or the χ2-method. In experiments extracting five topic words using a χ2-based model, we achieve 72% precision and 12% recall for speech recognition results. Speech recognition results generally include a number of recognition errors, which degrades topic extraction performance. To avoid this, we employ N-best candidates and likelihood given by acoustic and language models. In experiments, we find that extracting five topic words using N-best candidate and likelihood values achieves significantly improved precision.

This paper reviews the advantages of the silicon three-dimensional MMIC technology such as low loss transmission lines, high integration level, and high Q-factor on-chip inductors. Coupled to the masterslice concept, this technology also offers simple design procedure, short turn-around-time, low cost, and potential integration with LSI circuits. A K-band amplifier and an up-converter demonstrate the high frequency operation and low-power consumption benefits of the Si 3-D MMIC technology. A C-band Si-bipolar single-chip transceiver is proposed to illustrate the high integration level offered by the masterslice concept. Finally, the recent advances we achieved toward high Q-factor on-chip inductors provide the design of the S-band low noise amplifier presented in this paper.

In this paper, we introduce a concept of minimum bandwidth guaranteed service model for mobile multimedia. In this service model, service is defined in the context of the guaranteed minimum bandwidth and the residual service share. Each flow under this service model is guaranteed with its minimum bandwidth and provided with more in proportion to the residual service share if there is leftover bandwidth. The guaranteed minimum bandwidth assures a flow to keep minimum tolerable quality regardless of the network load, while the leftover bandwidth enhances the quality of service according to the application's adaptivity and the user's interest. We show that the minimum bandwidth guaranteed service model could be implemented by a two-folded wireless packet scheduler consisting of a guaranteed scheduler and a sharing scheduler. Wireless channel condition of each flow is considered in scheduling so that wireless resource can be distributed only to the flows of good channel state, improving total wireless link utilization. We evaluate the service model and the scheduling method by simulation and implementation.

The IETF Mobile IP defines two multicast options: remote subscription (RS) and bi-direction tunneling (BT). In order to synthesize the strong points of these two IETF multicast options, we propose a hybrid approach, mMOM, which selectively uses two IETF multicast options based on the mobility of mobile hosts. Whenever a mobile host requests its first registration to a certain foreign agent, the corresponding foreign agent starts the service using the BT option. Afterwards, if it requests re-registration to the same foreign agent, the foreign agent considers it to be relatively immobile and continues services using the RS option. We propose a new metric to compare heterogeneous algorithms. Simulation results show that our approach outperforms all others.

The adsorption behavior of cytochrome c was investigated using slab optical waveguide (SOWG) absorption spectroscopy at the near ultraviolet region utilizing thin quartz plates as planar waveguides. SOWG absorption spectra of cytochrome c measured at constant time intervals showed significant influence of surface hydrophilicity and solution chemistry on the adsorption of this important heme protein in quartz surface. Being polar and typically amphoteric, the protein preferred adsorption on hydrophilic surface than on hydrophobic surface as implied by the lower absorbance data obtained in the latter than in the former. At lower ionic strength and in the absence of buffer, the protein molecules tend to adsorb on the quartz surface. Plots of near steady-state absorbance versus protein concentration follow hyperbolic pattern in the absence of buffer or at low ionic strength and become more linear as the buffer concentration is increased. The results presented here are explained in terms of the general qualitative understanding of protein adsorption at solid-aqueous interfaces and further aids in elucidating the properties of protein monolayers and films.

Organic light emitting diodes (OLEDs) containing nanostructured cathode buffer layers were fabricated, and their electrical and emitting properties were investigated. The OLEDs have an ITO anode/CuPc/TPD/Alq3/buffer layer/Al cathode structure with the buffer layers made from nanostructured alternating layers Alq3 and Al. The driving voltage and the efficiency of the devices were improved by insertion of the buffer layer. It was estimated that some modulations of the Schottky barrier at the Alq3 and the Al cathode interface were induced due to the insertion of the buffer layer and it caused an enhancement of electron injection from the Al cathode.

Semistructured data comprises irregular structure and has no a-priori database schema, therefore we encounter several problems such as inefficient data retrieval and wasteful data storage. To cope with such problems, some schema extraction algorithms over semistructured data have been proposed, in which data is modeled as an unordered tree. However, the order of elements is indispensable for document data, therefore we consider extracting an optimal database schema over an ordered tree. We consider an optimization problem to extract a smallest database schema such that the density of each class is no less than a given threshold, where the density of a class represents a similarity between the type of the class and those of the objects in the class. We first prove that the corresponding decision problem is strongly NP-complete, and show that another version of the problem is strongly NP-hard and belongs to Δ2 P. Then we show that for any r < 3/2, there is no polynomial-time r-approximation algorithm that solves the optimization problem unless P = NP. Finally, we propose a kind of class called bounded class that can be constructed efficiently, then show a polynomial-time algorithm for constructing a database schema by using bounded classes.

The prospects of electron spectroscopy of working organic electronic device structures are discussed. The experimental consideration and the result of actual measurement are presented.

A new MAC protocol using the Adaptive Weighted Round Robin with Delay Tolerance (AWRR/DT) is presented. The proposed protocol is a type of centralized MAC protocol where the base station performs most operations. By using the AWRR/DT scheduler, we can guarantee delay QoS to different traffics without the heavy overhead induced by packet-based tagging techniques. In order to enhance the efficiency of random access systems, the proposed protocol employs three novel contention methods: slotted ALOHA with threshold, contention method using adaptive contention period, and traffic-specific contention method. Simulation results show that the proposed protocol guarantees delay bounds by using the AWRR/DT. The slotted ALOHA with threshold suffers less collisions than the regular slotted ALOHA when mobile terminals request slots. The method using adaptive contention period adjusts the length of contention period of each frame to relieve the performance degradation by collisions. The traffic-specific contention method provides a priority handling mechanism to contention-based systems. Experimental results of each contention method are provided.

A study of apple flavor, banana flavor, and their chemical components was performed using an array of quartz crystal microbalance (QCM) gas sensors coated with sensing films such as lipids or stationary phase materials for gas chromatography (GC). The steady state sensor responses measured by a static measurement system were used to evaluate the characteristics of the different samples by principal component analysis (PCA) method. Since the array has shown good discrimination properties for fruit flavor components providing useful information, it was used to investigate the components that primarily contribute to the odor of the flavors. The results obtained from principal components analysis aided by sensory test were also used for an attempt to synthesize apple and banana flavors using only three of its odor components.

The understanding of instruction set usage in typical DOS/Windows applications plays a very important role in designing high performance x86 compatible microprocessors. This paper presents the tools to such analysis, the analysis results, and their implications on the design of a RISC-based superscalar processor for efficient x86 instruction execution. The analyzed results are used to optimize the execution of frequently executed instructions and micro operations.

This paper proposes design of new linear bipolar OTAs using hyperbolic circuits with an intermediate voltage terminal. Four types of the OTAs are presented; two OTAs contain a hyperbolic sine circuit and the other two OTAs employ a hyperbolic cosine circuit. The linear input voltage range of the proposed OTAs is wider than that of the well-known conventional OTA, multi-TANH doublet, while each proposed OTA has advantages, such as low power dissipation, high-frequency characteristics and so on. The results of SPICE simulation show that satisfactory characteristics are obtained.

This paper deals with two-processor nonpreemptive scheduling problem for acyclic SWITCH-less program nets including two types of nodes: AND-node and OR-node. Compared with task graphs that are a special case of acyclic SWITCH-less program nets and include only AND-nodes, the multiprocessor scheduling problem of general acyclic SWITCH-less program nets is more complicated. Since multiprocessor scheduling problem for general task graphs is NP-hard, so is for acyclic SWITCH-less program nets generally. In this paper, we suppose the acyclic SWITCH-less program nets satisfy: (i) each AND-node and OR-node have 1 and 0 node firing time, respectively; (ii) each AND-node possesses single input edge. For such a class of acyclic SWITCH-less program nets, we first propose a hybrid priority list L that consists of both dynamic and static sub-lists. Then we prove that, for a given acyclic SWITCH-less program net to be executed by two identical processors, the schedule generated by L is optimal.

The concept of the equi-phase curve is introduced for the cross-polarized channel case. It is proved that the equi-phase curves are a series of half circles on the Poincare sphere, and that all these curves have two common ends. Based on the introduced concept, this letter demonstrates the distribution of the received voltage's phases on the Poincare sphere. In addition, it is shown theoretically that the cross-polarized phase of the off-diagonal elements of a scattering matrix is unstable for most natural targets. Therefore, the cross-polarized phase information cannot be used for extracting target characteristics in polarimetric radar remote sensing.

A new single resistance controlled quadrature oscillator using two current differencing buffered amplifiers (CDBAs), four resistors and two grounded capacitors is presented. Outputs of two sinusoidal signals with 90phase difference are available in the proposed quadrature oscillator. The oscillation condition and oscillation frequency of the proposed quadrature oscillator are independently controllable through different resistors. The proposed quadrature oscillator employs only grounded capacitors. The use of only grounded capacitors is ideal for integration. Simulation results are included.

It has been shown that the performances of single-receiver ARQ schemes are largely dependent on the packet-error process, i.e., for dependent packet-error environment, they are under- or over- estimated by analyzing them under the assumption that packet-errors occur at random. While, multi-receiver ARQ's have not been analyzed and evaluated for dependent packet-error process. In this paper, we analyze the throughput efficiency of the fundamental multi-receiver Go-back-N ARQ scheme, which can be implemented very simply, over an unreliable channel modeled by the two-state Markov process. Any receiver erroneously receives a packet with probability inherent to each state. From numerical results, we show that the throughput efficiency of the fundamental multi-receiver Go-Back-N ARQ scheme depends on the number of receivers, round-trip-delay, and the characteristic of the Markov process. Also we show that the throughput efficiency of the fundamental multi-receiver Go-Back-N ARQ scheme for larger decay factor and larger difference between packet error probability at each state is considerably better than that for the random error pattern.

The optical recording on an azopolymer surface by the optical fiber probe with a 100 nm diameter aperture was demonstrated. The 150 nm diameter pit was formed by the optical fiber probe coupled with a 50 ns pulse of 10 mW and 488 nm wavelength coherent light.