This paper first examines the issues related to scheduling loop applications on a software distributed shared memory (DSM) system. Then, a dynamic scheduling scheme is developed based on the examined issues to enhance the performance of loop applications on DSM. Compared with previous works, the proposed scheme has several specialties. The first is that the workload of processors can be effectively balanced even when the computational capabilities of processors and the computational needs of threads are not identical. The second is it divides thread mapping into two phases, each with one consideration, i.e., load balance or communication cost, and adopts thread migration and exchange in the two phases, respectively. The third is the exploitation of data sharing among threads to reduce data-consistency communication, and the last is to attack the negative effect of the unnecessary inter-node sharing caused by thread re-mapping. The proposed scheme has been implemented on a page-based DSM system called Cohesion. Our experiments show that the proposed scheme is more effective to improve the performance of the test programs than related schemes.

We report a directly deposited dielectric multilayer onto an end face of a fluorinated polyimide optical waveguide by ion beam sputtering process. This dielectric multilayer (Ta2O5/SiO2) acts on a wavelength separation filter which passes 1310 nm wavelength signal and reflects 1550 nm wavelength signal.

The radiation emission in far zones from printed circuit boards (PCBs) is obtained by treating lines on PCBs as transmission lines and calculating the far-field emission due to current distribution on lines. In this paper, we present a more precise circuit model, based on TEM assumption, to decompose the total current into differential-mode current and common-mode current. This circuit model is based on transmission line model, but it considers the effect of ground trace. The finite size ground trace can be viewed as an inductive reactance. A knowledge of the net inductance of the ground trace can aid in the analysis and investigation of PCBs emission. We show the derived equations of the modified transmission lines for the geometrics of practical interest. As time-varying current passes through such ground trace, a voltage drop due to the inductance of the trace will act as a source of the common-mode current. Furthermore, charge stored in capacitance between signal and ground traces will cause the current pulses returning to their source. The magnitudes of currents are slightly unequal in the signal and ground traces, which can cause common-mode current to flow. An unbalanced circuit on a PCB constructed with signal and ground trace pairs will radiate as an asymmetric folded-dipole. By antenna theory, the contribution of differential-mode and common-mode currents to radiated emission of PCBs can be calculated. In addition, comparisons between experimental results and calculation results are also given.

Ferromagnetic Co77Cr20Ta3 layers were deposited on a Pt seed layer by a facing targets sputtering apparatus. The Co-Cr-Ta and Pt crystallites revealed better c-axis orientation at a substrate temperature Ts above 200C. Relatively high perpendicular coercivity Hc⊥ of 2.5 kOe was obtained for the bilayered film with a Co-Cr-Ta layer thickness, δCo, of 50 nm deposited at Ts of 250C. Although the Co-Cr-Ta/Pt medium with δCo of 100 nm exhibited lower recording density than a Co-Cr-Ta/Cr longitudinal one, its noise level became small at the high-density recording range. Measurement of the anomalous Hall voltage clarified that the bilayered film with δCo as small as 30 nm revealed larger perpendicular magnetization than the single layer. The Pt seed layer is effective for depositing thin ferromagnetic Co-Cr-Ta layers below 100 nm in thickness.

This paper describes how to generate, analyze and design a novel current-mode filter model using tunable multiple-output operational transconductance amplifiers and grounded capacitors (MO-OTA-Cs) for synthesizing both transmission poles and zeros. Transfer functions of low-order, high-order, general type, and special type are realized based on the filter model. The theory focuses mainly on establishing a relationship between the cascaded MO-OTA-Cs and the multiple-loop feedback matrix, which makes the structural generation and design formulas. Adopting the theory allows us to systematically generate many interesting new configurations along with some known structures. All the filter architectures contain only grounded capacitors, which can absorb parasitic capacitances and require smaller chip areas than floating ones. The paper also presents numerical design examples and simulation results to confirm the theoretical analysis.

The interconnect analysis of on- and off-chips is very important in the design of high-speed signal processing, digital communication, and microwave electronic systems. When the interconnects are characterized by sampled data via electromagnetic analysis, the circuit-level simulation of the network requires rational approximation of the sampled data. Since the frequency band of the sampled data is more than 10 GHz, the rational function must fit into it at many frequency points. The rational function is approximated using the orthogonal least-squares method. With an increase in the number of the fitting data, the least-squares method suffers from a singularity problem. To avoid this, the sampled data are hierarchically approximated in this paper. Moreover, to reduce the computational cost of the circuit-level simulation, the parameter matrix of the interconnects is approximated by a rational matrix with one common denominator polynomial, and the selective orthogonalization procedure is presented.

A low bit-rate encoding method which yields a good performance in edge reconstruction while achieving a high compression is proposed through MTF function and the spatial anisotropy of human vision. Human visual weighting factors applied to sub-blocks within each subband in wavelet domain are produced by the spatial anisotropic-filter, then a good perceptual performance can be obtained.

At the sliding contact of brush and rotating slip-ring or commutator, it has been recognized that the brush wear is influenced by brush pressure, current density and atmosphere nearby contact part. However, little is known about the relation between brush wear and atmosphere condition in detail. In this paper, the experiments are carried out with a great attention to the effect of surrounding temperature and humidity on brush wear. The sliding part of brush and slip-ring is put on the sealed box and the atmosphere in the sealed box is kept on the specified condition by temperature and humidity control system. The brush wear, contact voltage drop and slip-ring surface morphology are observed after the sliding test. From these results, in both cases of the high humidity (nearby 80%) and low humidity (nearby 20%), the brush wear are large. And the brush wear rate is the lowest around 60% relative humidity. However, the characteristics of brush wear under the 15C is not similar to others. When the surrounding temperature is changed, in case of the 20% humidity, the brush wear increases with increasing surrounding temperature. On the other hand, in case of 80% humidity, the brush wear increases with decreasing surrounding temperature. Consequently, the results clearly shows that the temperature and humidity not only affect the brush wear but also change the condition of the film formation on slip-ring.

A Rayleigh lidar (laser radar) system was developed and is now working well for temperature observations of the middle atmosphere at Poker Flat Research Range near Fairbanks, Alaska (65.1 N, 147.5 W). A comparison of lidar data and balloon sonde data showed good agreement in overlapped altitudes. The atmospheric fluctuations are detected in the temperature profiles obtained by the Rayleigh lidar and these are useful for the study of gravity waves. A Rayleigh Doppler lidar for wind measurements of the middle atmosphere is under the phase of development. The expected accuracy in measurements of horizontal winds up to an altitude of 60 km is smaller than 6 m/s in 2 hours observation. The system will be operated at Poker Flat after the completion of development. The combination of these lidars and radars installed at Poker Flat, give us chances of simultaneous observations of the structure and dynamics of the atmosphere in broad range of altitudes. Here, we give descriptions of the Rayleigh lidar and the Rayleigh Doppler lidar for the observations of the Arctic middle atmosphere at Poker Flat.

An airborne X- and L-band synthetic aperture radar system was developed by the Communications Research Laboratory and the National Space Development Agency of Japan in their joint project from 1993 to 1996. It is installed in the airplane, Gulfstream II. In both the azimuth and range directions, the resolution is 1.5 m for the X-band and 3 m for the L-band. Both SARs can make fully polarimetric observations. The X-band SAR has a cross-track interferometric function. In this paper we describe the SAR system, its ground processing system, and its performance. We also discuss motion compensation and interferogram quality.

This paper presents an application of Complex-Valued Associative Memory Model(CAMM) for image processing. An image association system applying CAMM, combined with a 2-dimensional discrete Fourier transform (2-D DFT) process is proposed. Discussed are how a gray level image can be expressed using CAMM, and the image association that can be performed by CAMM. In the proposed system, input images are transformed to phase matrices and the image association can be performed by making use of the phase information. Practical examples are also presented.

In this paper, as a practical application, we focus on the genetic algorithm (GA) for multi-head surface mounting machines which are used to populate printed circuit boards (PCBs). Although there have been numerous studies on the surface mounting machine, studies on the multi-head case are rare because of its complexity. The multi-head surface mounting machine can pick multiple components simultaneously in one pickup operation and this operation can reduce much portion of the assembly time. Hence we try to minimize the assembly time by maximizing the number of simultaneous pickups, resulting in reduction of PCB production cost. This research introduces a partial-link GA method for the single-head case. Then, we apply this method to the multi-head case by regarding a reel-group as one reel and a component-cluster as one component. The results of computer simulation show that our genetic algorithm is greatly superior to the heuristic algorithm that is currently used in industry.

Co-ferrite thin films have been fabricated on Corning glass substrates by a chelating sol-gel process. Structural and magnetic properties of the films have been studied as a function of annealing temperature using an X-ray diffraction (XRD) and a vibrating sample magnetometer. XRD results revealed that most of the Co-ferrite grains were randomly oriented. Rapid annealing (RA) and standard annealing (SA) processes were used for the variation of heat treatment and the characteristic comparison. Coercivity was changed with the thermal condition and the magnetization increased with the soaking time. With prolonged soaking time, however, the coercivity decreased due to the diffusion of cations from the glass substrate. RA in the preparation of Co-ferrite thin films was effective for preventing interdiffusion at interfaces and for forming a single phase in the case of reduced soaking time. A yttria stabilized zirconia (YSZ) buffer layer between the Co-ferrite layer and the substrate was effective for improving the magnetic properties of the films at higher temperatures. It was observed that Co-ferrite thin films were composed of grains typically 35 nm in size and their rms roughness was approximately 1.3 nm. The saturation magnetization of the thin films by subjected to rapid annealing at 900C for 150 seconds was 400 emu/cm3 and the coercivity of the films was approximately 3000 Oe.

In Optimistic Two-Phase Locking (O2PL), when a transaction requests a commit, the transaction can not be committed until all requested locks are obtained. By this reason, O2PL leads to unnecessary waits and operations even though it adopts an optimistic approach. This paper suggests an efficient optimistic cache consistency protocol that provides serializability of committed transactions. Our cache consistency scheme, called PCP (Preemptive Cache Protocol), decides whether to commit or abort without waiting when transactions request commits. In PCP, some transactions that read stale data items can not be aborted, because it adopts a re-ordering scheme to enhance the performance. In addition, for re-ordering, PCP stores only one version of each data item. This paper presents a simulation-based analysis on the performance of PCP with other protocols such as O2PL, Optimistic Concurrency Control and Caching Two-Phase Locking. The simulation experiments show that PCP performs as well as or better than other schemes with low overhead.

This paper concentrates on the model useful for analyzing the error performance of M-estimators of a single unknown signal parameter: that is the error intensity model. We develop the point process representation for the estimation error, the conditional distribution of the estimator, and the distribution of error candidate point process. Then the error intensity function is defined as the probability density of the estimate and the general form of the error intensity function is derived. We compute the explicit form of the intensity functions based on the local maxima model of the error generating point process. While the methods described in this paper are applicable to any estimation problem with continuous parameters, our main application will be time delay estimation. Specifically, we will consider the case where coherent impulsive interference is involved in addition to the Gaussian noise. Based on numerical simulation results, we compare each of the error intensity model in terms of the accuracy of both error probability and mean squared error (MSE) predictions, and the issue of extendibility to multiple parameter estimation is also discussed.

Triple-layer CoCrPt magnetic thin films with different bias configurations were fabricated by DC magnetron sputtering on CrV and glass substrate. In-plane coercivity (Hc) showed an increase for those films with bias sputtered CoCrPt layer. The in-plane coercivity (Hc) was optimized in NB-B-NB type film prepared with substrate heating at 300C (NB: no bias and B: rf bias applied in sputtering). Better in-plane crystal texture was observed in NB-B-NB type film by XRD and this is believed to be the main reason for the coercivity improvement. The other resource for the coercivity improvement was due to the decoupling of intergrain magnetic interactions. This was discussed accordingly to the results obtained from TEM, MFM and SIMS depth profiling.

This paper investigates the modeling of non-linearity on the generation of the single trial evoked potential signal (s-EP) by means of using a mixed radial basis function neural network (M-RBFN). The more emphasis is put on the contribution of spontaneous EEG term to s-EP signal. The method is based on a nonlinear M-RBFN neural network model that is trained simultaneously with the different segments of EEG/EP data. Then, the output of the trained model (estimator) is a both fitted and reduced (optimized) nonlinear model and then provide a global representation of the passage dynamics between spontaneous brain activity and poststimulus periods. The performance of the proposed neural network method is evaluated using a realistic simulation and applied to a real EEG/EP measurement.

The development of Radar Polarimetry and Radar Interferometry is advancing rapidly. Whereas with radar polarimetry, the textural fine-structure, target orientation, symmetries and material constituents can be recovered with considerable improvement above that of standard amplitude-only radar; with radar interferometry the spatial (in depth) structure can be explored. In Polarimetric Interferometric Synthetic Aperture Radar (POL-IN-SAR) Imaging, it is possible to recover such co-registered textural and spatial information from POL-IN-SAR digital image data sets simultaneously, including the extraction of Digital Elevation Maps (DEM) from either Polarimetric (scattering matrix) or Interferometric (single platform: dual antenna) SAR systems. Simultaneous Polarimetric-plus-Interferometric SAR offers the additional benefit of obtaining co-registered textural-plus-spatial three-dimensional POL-IN-DEM information, which when applied to Repeat-Pass Image-Overlay Interferometry provides differential background validation, stress assessment and environmental stress-change information with high accuracy. Then, by either designing Multiple Dual-Polarization Antenna POL-IN-SAR systems or by applying advanced POL-IN-SAR image compression techniques, it will result in POL-arimetric TOMO-graphic (Multi-Inter-ferometric) SAR or POL-TOMO-SAR Imaging. This is of direct relevance to local-to-global environmental background validation, stress assessment and stress-change monitoring of the terrestrial and planetary covers.

This paper investigates an obstructed radio channel by foliage for LMDS (local multipoint distribution services) where a relative evaluation of attenuation characteristics of foliage at 29.5 and 5 GHz is performed. Results show that the attenuation in dB should be treated statistically as Rician distribution. It is also found that swaying foliage in wind causes a significant channel fading at 29.5 GHz, ranging over 10 dB, while the fading depth at 5 GHz is approximately 2 dB.

We analyze the performance of soft handoff used as intergroup handoff in the fiber-optic cellular system. Performance is evaluated in view of blocking and handoff refused probability. The numerical results show that the smaller the handoff region or the more the channel, the larger the system capacity.