Solution space smoothing allows a local search heuristic to escape from a poor, local minimum. In this paper, we propose a technique that can smooth the rugged terrain surface of the solution space of a placement problem. We test the smoothing heuristics for MCNC benchmarks, and for VLSI placement with pre-placed modules and placement with consideration of congestion. Experiment results demonstrated that solution space smoothing is very efficient for VLSI module placement, and it can be applied to all floorplanning representations proposed so far.

In this paper, a new grouping method for Group Technology using Self-Organizing Map (SOM) is proposed. The purpose of our study is to divide machines in a factory into any number of cells so that the machines in each cell can process a similar set of parts to increase productivity. A main feature of our method is to specify not only the number of the cells but also the maximum and minimum numbers of machines in a cell. Some experimental results show effectiveness of our proposed algorithm.

Field-theoretical equivalent circuit models of a variety of coplanar waveguide (CPW) lumped-element discontinuities for two dominant modes are characterized by executing the short-open calibration (SOC) procedure in the fullwave method of moments (MoM). In our developed MoM platform, the impressed current sources with even or odd symmetry are introduced at the selected ports in order to separately excite the even and odd dominant modes, i.e., CPW- and CSL-mode. After the port network parameters are numerically derived using the Galerkin's technique, the two SOC standards are defined and evaluated in the self-consistent MoM to effectively de-embed and extract the core model parameters of a CPW circuit or discontinuity. After the validation is confirmed via comparison with the published data, extensive investigation is carried out to for the first time demonstrate the distinctive model properties of one-port CPW short- and open-end elements as well as two-port inductive and capacitive coupling elements with resorting to its two different dominant modes.

We have developed a three-dimensional eye movement simulator that simulates eye movement. The simulator allows us to extract the instantaneous eye movement rotation axes from clinical data sequences. It calculates the plane formed by rotation axes and displays it on an eyeball with rotation axes. It also extracts the innervations for eye muscles. The developed simulator is mainly programmed by a CG programming language, OpenGL. First, the simulator was applied to saccadic eye movement data in order to show the so-called Listing's plane on which all hypothetical rotation axes lie. Next, it was applied to clinical data sequences of two patients with benign paroxysmal positional vertigo (BPPV). Instantaneous actual rotation axes and innervations for eye muscle extracted from data sequences have special characteristics. These results are useful for the elucidation of the mechanism of vestibular symptoms, particularly vertigo.

The present paper discusses an assembly line balancing problem (ALBP). ALBP discussed up to now does not consider rack spaces where tools or parts are stored. We introduce an extended resource planning and assembly line balancing problem that takes the rack space into account. An exact search method for solving the problem by using a graph structure, and a heuristics for the method are proposed. The proposed method is evaluated by computational experiments.

In this paper, we proposed the doubly tapered electromagnetic periodic structure (DT-EPS) bandstop filters in coplanar waveguide (CPW) and cylindrical coplanar waveguide (CCPW). The DT-EPS bandstop filter not only can effectively improve the stopband rejection but also increase its bandwidth. In addition, this technique can significantly reduce the passband ripples compared with conventional case.

We present excellent performance of a novel two-stage SiGe hetero-bipolar transistor (HBT) power amplifier (PA) in which different collector doping structures were employed for the first and second stages. A selectively ion implanted collector (SIC) structure was employed for the first stage HBT in order to obtain a high gain, while without-SIC structure was used for the second stage HBT in order to achieve a high breakdown voltage. At 1.95 GHz, the total PAE of 31% and a gain of 28 dB with an output power (Pout) of 26 dBm were obtained while the adjacent channel power ratio (ACPR) was less than -38 dBc for W-CDMA modulation signals.

A low energy plasma based on an electron discharge was investigated for the pre-epi clean of silicon wafers and for plasma enhanced homo and hetero epitaxial growth of Si and SiGe layers. VS were produced in a short, completely dry process sequence consisting of LEPC and LEPECVD only. The wafer/epilayer interface obtained in this process sequence was suitable to grow high quality VS with low surface roughness and dislocation densities. Based on this process and its implementation in a 200/300 mm single wafer cluster tool, a high volume and economical production of VS seems possible.

This paper presents a novel data placement and retrieval scheme for video-on-demand systems. In particular, a zone-based data placement scheme is employed to reduce the average seek time of the disk array storage system and thus increase the disk access bandwidth to allow the video server provide more services of video programs concurrently. Furthermore, due to the inherent nature of video access, a popular program always requires more accesses and therefore occupies more disk I/O bandwidth as request for serving such program increases. A new retrieval strategy is proposed to maintain a single copy of each video program disregarding the popularity of the video programs, and to achieve maximum I/O throughput of the video server.

In this paper, the time-frequency separation algorithm (TFS) proposed by Belouchrani and Amin is applied to ground penetrating radar (GPR) data to reduce ground clutter, that hides reflected waves from a near-surface planar interface. We formulated the problem with several assumptions so that narrow band signals, whose center frequency and baseband signal depend on propagation paths, are received at the receiver, when a wideband signal is radiated from a transmitter. These phenomena can be clearly seen in time-frequency distribution (TFD) of the received signal. In this paper, we adopted the TFS utilizing the TFD signature as a blind separation technique to separate the ground clutter from the target signals. We show numerical and experimental results in order to verify the validity of the problem formulation and the TFS. We carried out GPR measurements to measure permafrost in Yakutsk, Russia. We found the difference in TFD signatures between the ground clutter and the target signal in the experimental data. We could detect the upper boundary of the permafrost with the TFS in spite of the unstable ground clutter.

This paper describes an experimental study on resonant properties of the plasma-wave field-effect transistors (PW-FET's). The PW-FET is a new type of the electron devices, which utilizes the plasma resonance effect of highly dense two-dimensional conduction electrons in the FET channel. Frequency tunability of plasma-wave resonance in the terahertz range was experimentally investigated for sub 100-nm gate-length GaAs MESFET's by means of laser-photo-mixing terahertz excitation. The measured results, including the first observation of the third-harmonic resonance in the terahertz range, however, fairly deviate from the ideal characteristics expected for an ideal 2-D confined electron systems. The steady-state electronic charge distribution in the MESFET channel under laser illumination was analyzed to study the effect of insufficient carrier confinement on the frequency tunability. The simulated results support the measured results. It was clarified that an ideal heterostructure 2-D electron confinement is essential to assuring smooth, monotonic frequency tunability of plasma-wave resonance.

We have demonstrated AlGaN/GaN high electron mobility transistors (HEMTs) grown on epitaxial AlN/sapphire templates. The crystal qualities and fabricated device performances between AlGaN/GaN HEMTs on epitaxial AlN/sapphire templates and conventional AlGaN/GaN HEMTs on sapphire substrates with low-temperature buffer layer (LT-BLs) are compared with each other. By using epitaxial AlN/sapphire templates instead of LT-BLs, higher mobility was exhibited and superior crystal qualities were observed, as confirmed by X-ray diffraction (XRD), atomic force microscopy (AFM) images and capacitance-voltage measurements. In addition, the dc characteristics of the fabricated devices on epitaxial AlN/sapphire templates were enhanced. AlGaN/GaN HEMTs on epitaxial AlN/sapphire templates are promising candidates for practical applications of nitride-based electronic devices.

Employing a triangular dielectric phase shifter simplifies the beam forming network of an offset beam array antenna because this structure achieves phase control in a single configuration. This paper proposes a design method for a low loss offset beam planar antenna that incorporates a triangular dielectric plate phase shifter on parallel microstrip feedlines. Our design method reduces the loss of the phase shifter by optimizing the microstrip line width. By using the proposed design equation, the optimum low loss phase shifter configuration can be easily established. In addition, this paper presents the actual design of a triangular plate considering size reduction. The results of experiments of the offset beam antenna indicate that our design method is effective in obtaining a simple, low loss, and compact configuration.

The array-enhanced coherence resonance (AECR) in the diffusively coupled active rotators is investigated and its analysis with the nonlinear Fokker-Planck equation is presented. By considering the nonlinear Fokker-Planck equation of the rotators, it is found that the time-periodic solution exists in some parameter range. By solving the equation of a rotator and the Fokker-Planck equation simultaneously, the behavior of a rotator in the system with infinite number of rotators is considered, and it is found that AECR also takes place in this infinite system. Thus it is concluded that AECR is caused by the time-periodic solution of the probability density induced by noise.

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.

Implementation issues on generalized multi-protocol label switching (GMPLS) -based photonic switching networks are experimentally analyzed. A resilient control plane architecture using in-fiber and out-of-fiber control channels is proposed to resolve issues of establishing the control plane in out-of-band networks. The resilient control plane is demonstrated in a photonic cross-connect (PXC) -based GMPLS network involving a 1,000 km transmission line. Fast signaling for provisioning and restoration operation is accomplished by implementing in-fiber control channels as primary, and the out-of-fiber control channels effectively operate as secondary and restore messaging of the control information between neighbors. The control channel protection is initiated by the link management protocol (LMP). Using the test bed, optical layer routing operation is investigated to assess the effects on the signal quality of wavelength paths, and transparent routing of the wavelength paths over one-hop and two-hops route is demonstrated within 1 dB difference regarding the Q factor. Stable operation of loss of light (LOL) -triggered restoration is demonstrated by setting the optical level threshold 5 dB higher than the amplified spontaneous emission (ASE) noise level.

In this paper, our aim is to extract real-time movement-related potentials, especially readiness-potentials, from EEGs with a small number of scalp electrodes. We proposed a method composed of independent component analysis (ICA), dipole tracing (DT) and scalp Laplacian methods. The proposed method shows a good real-time RP extraction capability from a single-trial of movement by means of the selection of EEGs with high reliability based on the DT and the improvement of the spatial resolution of the scalp potentials based on the scalp Laplacian.

A compact high-temperature superconducting (HTS) bandpass filter (BPF) using coplanar waveguide (CPW) meander-line parallel-circuited resonators is proposed for microwave receiver applications. The design theory is presented based on a conventional filter theory with J-inverters. Also, analytical and numerical studies of the meander-line resonator are carried out in terms of equivalent circuit values, the resonant frequency, and the unloaded Q. Two- and four-stage 0.05 dB ripple Chebyshev BPFs at 2 GHz with relative bandwidth 60 MHz are fabricated with the metalorganic deposition (MOD)-derived YBCO films on LaAlO3 substrates and their performance are demonstrated. The measured frequency characteristics and the unloaded quality factors agree well with the theoretical and numerical results and the validity of the design theory is confirmed.

In this paper, we present a technique to obtain an accurate closed-form spatial Green's function for a coplanar waveguide. The integration of the Sommerfeld integrals is performed on the real axis, and the path deformation is avoided in the sampling data. The results are in good agreement with the numerical integration over wide ranges of the signal frequency and the observation distance.

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.