Progress in WDM transmission technology and the development of optical cross-connect systems has made optical backbone networks a reality. The conventional planning methodologies for such optical backbone networks calculate optimum light-path arrangements to minimize the network cost under the condition that the number of demanded light-paths is given in advance. However, the light-path demand varies according to the light-path prices. Thus, a new planning methodology for the optical backbone networks is necessary to optimize the light-path prices and to maximize the profit obtained from the network. This paper proposes a new planning methodology for the survivable optical networks. This methodology is based on economic theory for competitive markets involving plural kinds of commodities. Using this methodology, the optimum light-path prices can be decided to maximize the obtained profit. A numerical example is presented to show that the obtained profit can be improved by preparing various light-path classes with different recovery modes and introducing an appropriate light-path pricing according to the reliability of each light-path class.

In this paper we describe the investigation of design methodology of a planar duplexer consisting of BPFs using mixed tapped resonators. Firstly, we propose the planar duplexer consisting of bandpass filters (BPFs) using a tapped open-ended λ/2 resonator and a tapped λ/4 resonator. The duplexer is designed based on the general filter theory with narrow band approximation and tap-coupling technique. The actual duplexer is fabricated using a coplanar waveguide (CPW). Secondly, downsizing of the planar duplexer is carried out based on the BPF using stepped impedance resonators (SIRs). Lastly, another type of duplexer consisting of different BPFs using mixed tapped resonators is investigated in the same manner. The results of this study lead us to the conclusion that the design methodology is useful for realizing the high-performance planar duplexer fabricated without increasing the number of elements.

The high-resolution frequency estimators most commonly used, such as Least Square (LS) method based on AR model, MVSE, MUSIC and ESPRIT, determine estimates of the sinusoidal frequencies from the sample noise-corrupted data. In this paper, a new frequency estimation method named Pole-Placement Least Square (PPLS) is presented, which is a modified LS method with a certain number of model poles restricted to the unit circle. The statistical performance of PPLS is studied numerically, and compared with the Cramer-Rao bound as well as the statistical performance corresponding to the LS methods. PPLS is shown to have higher resolution than the conventional LS method. The relationship between poles location and its resolution is also discussed in detail.

The technique of replica placement has been extensively employed to improve client perceived performance and disperse server workload. In this paper, we study some well-known algorithms of replica placement on the network and observe the logarithmic relationship between replica number and total access cost. Numerous simulations are done and it is found that some replica algorithms obey the logarithmic relationship with high correlation coefficients. A logrithmic function is proposed about replica number and total access cost. The logarithmic relationship is applied to the minimum facility problem and a function is deduced to get the optimal replica number.

A "rooted" plane triangulation is a plane triangulation with one designated vertex r and one designated edge incident to r on the outer face. In this paper we give a simple algorithm to generate all connected rooted plane triangulations with at most m edges. The algorithm uses O(m) space and generates such triangulations in O(1) time per triangulation without duplications. The algorithm does not output entire triangulations but the difference from the previous triangulation. By modifying the algorithm we can generate all connected (non-rooted) plane triangulations with at most m edges in O(m3) time per triangulation.

The demand for wireless mobile communications has grown at a very high rate, recently. In order to solve the non-uniform traffic rates, the use of cell splits is unavoidable for balancing the traffic rate and maximizing total system capacity. For cell planning, a DS-CDMA cellular system can be comprise of different cell sizes because of different demands and population density of the service area. In this paper, we develop a general model to study the forward link capacity and outage probability of a DS-CDMA cellular system with mixed cell sizes. The analysis of outage probability is carried out using the log-normal approximation. When a macrocell is split into the three microcells, as an example, we calculate the multi-cross interferences between macrocells and microcells, and the forward link capacities for the microcells and the neighboring macrocells. The maximum allowable capacity plane for macrocell and microcell is also investigated. The numerical results and discussions with previous published results of reverse link are summarized.

In this paper, we first investigate the characteristics of movie contents over the Internet. As in the previous studies, we found the lognormal-distribution well fits the distribution of file size for the whole set of general movie contents. When we specifically focus on the subset that consists of movie trailers, however, it shows different distribution from the lognormal-distribution. Our analysis shows it is similar to an exponential-distribution. We here assume that movie trailers are one of the relevant contents for Contents Delivery Networks (CDN) or Peer-to-Peer (P2P) file exchange communities. We further studies the relationship between playing duration and file size for the movie trailers and we did not find any linear correlation among them. We next consider bandwidth requirements to retrieve movie trailer contents. Our objective is to make it possible for user to view the contents in real-time. Many previous studies investigate bandwidth requirement based only on the file size distribution. In this paper, we analyze the traffic design criteria for CDN or P2P by taking into account both of the results for the file size distribution and the relationship between playing duration and file size for movie trailers. Simulation studies reveal the impact for the bandwidth requirement.

In this paper, we try to establish a power law for contact resistance versus force Rc = KcFc-n , and we determine via experimental measurements and theoretical calculations, the constants n and Kc in the force range (1 mN-4 N) for bulk metal (Ag, Au, Pd, Ni) used in various applications (microswitches, connectors). The main experimental results of contact resistance are the occurrence of two decrease domains versus progressive load indentation. The first regime corresponds to the earlier touch of the coupon by the probe at force < 0.1 N. This elastic regime evolves to a plastic regime for medium force > 0.1 N. At the transition the exponent value n changes from 0.33 to 0.5 and induce Kc value increasing. Theoretical and computational approaches applied to the elasto-plastic model, confirm the occurrence of these two regimes. Although the calculated values of n are in good agreement with experimental values, some discrepancy between measured and calculated Kc values take place.

To sample a band-limited analog signal directly from the high frequency down to the baseband for the digital signal processing with significantly reduced computation, several concepts of the bandpass sampling are introduced. In this paper, a robust bandpass sampling scheme when there exist frequency deviations due to the channel effect and hardware instability is proposed for practical use, and the effects of the frequency deviations are discussed to select a proper sampling frequency.

Recently, Hwang and Yeh demonstrated that Peyravian-Zunic's password authentication scheme is vulnerable to several attacks, and then proposed a modified version. In this letter, we show that Hwang-Yeh's scheme still has several weaknesses and drawbacks.

We have formed simple polarization-controller arrays by inserting liquid crystal (LC) in trenches cut across planar lightwave circuits (PLCs). We fabricated LC layers for use as polarization controllers on PLCs in two ways; in one, the ultra-thin layer of LC is held in a cell that is inserted into a trench on the PLC while in the other, the trench is directly filled with the LC. The ultra-thin LC cell can change the phase of 1.55-µm light from 0 to 3π while the LC filling can change the phase of light at the same wavelength from 0 to 12π below 5Vrms. Two former parallel-aligned ultra-thin LC cells, where the directions of alignment of the liquid crystals are rotated by 45 relative to each other, are capable of converting light with an arbitrary input polarization to TE or TM polarization. Ultra-thin cells of twisted nematic LC can switch the polarization between TE and TM modes with an extinction ratio of -15dB. The array we fabricated had a pitch of 1 mm and 5 elements, but an array with more than 100 elements and a pitch below 125µm will easily be possible by using finely patterned transparent electrodes. We have also applied our techniques to the fabrication of LC-based variable optical attenuators (VOA) on the PLC.

Electron field emission from diamond, diamond-like carbon, carbon nanotubes and nano-structured carbon is compared. It is found that in all practical cases, emission occurs from regions of positive electron affinity with an emission barrier of 5eV, the work function, and with a large field enhancement. The field enhancement in nanotubes arises from their geometry. In diamond, the field enhancement occurs by depletion of grain boundary states. In diamond-like carbon we propose that it occurs by the presence of sp2-rich channels formed by the soft conditioning process.

A configurable device "PCA-Chip2" implements the concept of Plastic Cell Architecture, which is an extension of programmable logic devices. This paper presents basic design tools for the PCA-Chip2 as the first step to develop the total design environment. Given a C description of a target function, configuration data for PCA-Chip2 is automatically generated by the tools. Trial designs by the tools are also presented to demonstrate the practicability of the proposed approach.

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.

A "based" plane triangulation is a plane triangulation with one designated edge on the outer face. In this paper we give a simple algorithm to generate all biconnected based plane triangulations with at most n vertices and with maximum degree at most D. The algorithm uses O(n) space and generates such triangulations in O(1) time per triangulation without duplications. The algorithm does not output entire triangulation but the difference from the previous triangulation. By modifying the algorithm we can generate all biconnected based plane triangulations with exactly n vertices and maximum degree at most D in O(1) time per triangulation, and all biconnected (non-based) plane triangulations with exactly n vertices and maximum degree at most D in O(n3) time per triangulation without duplications.

Modern network technologies gave rise to intelligent network reconfiguration schemes for restoration purposes and several network self-healing schemes, exploiting the capabilities of network elements (NE), have already been proposed. Each self-healing scheme has its own characteristics, regarding restoration time, flexibility, restoration cost and exploitation of NEs. Integrated self-healing networks, which combine more than one survivability techniques, mainly the Shared Self-Healing Rings (SSR) with the Dynamic Self-Healing Networks (DSN), can achieve higher network survivability and cost-effective network design. In this paper, we propose two algorithms for the design of spare and working channel capacities for integrated self-healing networks. In the first algorithm, A1, we do not take into account the capacity of network nodes, while in the second algorithm, A2, we take into account the limited capacity of network nodes. These algorithms are based on the shortest path principles, similarly to a previous algorithm (old algorithm) proposed by scientists of NEC Corporation for integrated self-healing network design. By the new algorithms we achieve more savings than by the old algorithm in total network capacity. On the other hand, strong motivation for the development of the new algorithms is the fact that the procedural steps of the old algorithm are not homogeneous; the old algorithm incorporates both heuristics and analytical methods, in contrast to the new algorithms that are pure heuristics. Moreover, we introduce restrictions in node-capacities of the network that they were not included in the old algorithm.

The label placement problem is one of the most important problems in geographic information systems, cartography, graph drawing and graphical interface design. In this paper, we consider the problem of labeling points and curves in maps drawn from digital data. In digital maps, a curve is represented as a set of points and consists of many small segments. The label for each curve must be placed alongside the corresponding curve. We define a continuous labeling space for points and curves, and present an algorithm using this space for positioning labels. Computational results for subway and JR train maps in Tokyo are presented.

A new multi-luminance-level subfield method is proposed to reduce the low gray-level contour of an alternate current plasma display panel (AC-PDP). The minimum or maximum luminance level per sustain-cycle can be altered by simultaneously applying the proper auxiliary short pulses. As a result, the multi-luminance levels per one or two sustain pulse pairs can be expressed by properly adjusting the auxiliary short pulses for the one or two sustain-cycle subfields, thereby suppressing a low gray-level contour of AC-PDP.

A plane quadrangulation is a plane graph such that each inner face has exactly four edges on its contour. This is a planar dual of a plane graph such that all inner vertices have degree exactly four. A based plane quadrangulation is a plane quadrangulation with one designated edge on the outer face. In this paper we give a simple algorithm to generate all biconnected based plane quadrangulations with at most f faces. The algorithm uses O(f) space and generates such quadrangulations in O(1) time per quadrangulation without duplications. By modifying the algorithm we can generate all biconnected (non-based) plane quadrangulations with at most f faces in O(f3) time per quadrangulation.

Small-size MOSFETs are becoming core devices in RF applications because of improved high frequency characteristics. For reliable design of RF integrated circuits operating at the GHz range, accurate modeling of small-size MOSFET characteristics is indispensable. In MOSFETs with reduced gate length (Lg), the lateral field along the MOSFET channel is becoming more pronounced, causing short-channel effects. These effects should be included in the device modeling used for circuit simulation. In this work, we investigated the effects of the field gradient in the gate-drain capacitance (Cgd). 2-Dimensional (2D) simulations done with MEDICI show that the field gradient, as it influences the channel condition, induces a capacitance which is visible in the MOSFET saturation operation. Changes in Cgd is incorporated in the modeling by an induced capacitance approach. The new approach has been successfully implemented in the surface-potential based model HiSIM (Hiroshima-university STARC IGFET Model) and is capable of reproducing accurately the measured Cgd-Lg characteristics, which are particularly significant for pocket-implant technology. Results show that pocket-implantation introduces a steep potential increase near the drain region, which results to a shift of the Cgd transition region (from linear to saturation) to lower bias voltages. Cgd at saturation decreases with Lg due to steeper surface potential and increased impurity concentration effects at reduced Lg.