Block-matching-based motion field generation utilizing directional edge displacement

A motion field generation algorithm using block matching of edge flag histograms has been developed aiming at its application to motion recognition systems. Use of edge flags instead of pixel intensities has made the algorithm robust against illumination changes. In order to detect local motions of interest effectively, a new adaptive frame interval adjustment scheme has been introduced in which only the edge flags due to local motions present in the frame are accumulated and utilized in block matching. These edge flags are projected onto x and y axes to generate histograms and the motion in x and y directions are determined by histogram matching. As a result, the computational cost for best match search has been substantially reduced. A vector representation of the motion field, which is called projected principal-motion distribution (PPMD), has also been proposed. It was applied to preliminary motion recognition experiments using Hidden Markov Models (HMMs) and its effectiveness has been confirmed. Moreover the advantage of the proposed motion field generation method over the simple optical flow as well as the conventional block matching method using pixel intensities has been demonstrated.     

Ceramic material processing by electrical discharge in electrolyte

New ceramic materials receive a great deal of attention as machine components, but they are hard to work. So a hybrid processing which combines electrical discharge processing with grinding is proposed. In this study, in order to examine the possibility of this hybrid processing, the electrical discharge processing on four kinds of ceramics was carried out with a needle electrode. The ceramic materials were alumina and three kinds of silicon nitride series to which are added alumina (ASN), magnesia (MSN), yttria and alumina (YASN). The results obtained showed that a pit can be formed on any ceramic and the pit depth apparently varies with the ceramic material. The removal rates of ASN, alumina, YASN and MSN become low in turn, and are independent of their mechanical properties. In the case of the silicon nitride series, the removal rates depended on their sintering additives, and the higher the applied voltage, the greater was the volume removed. High removal rate and low electrode loss are obtained when the needle electrode is negative. The ceramic materials are mainly removed by etching the grain boundary in a high-temperature electrolyte during the discharging process.     

Various microstructures suggesting possible shock compaction mechanisms

In order to reveal mechanisms of the shock compaction process for metallic powders, a shock recovery experiment for equiatomic NiTi alloy powder was performed using the flyer plate impact technique, and the microstructure at the central region of the sample after the shock treatment was observed under a metallurgical microscope. It is clearly confirmed from the microstructures that the powder is compacted by three mechanisms: (1) generation of a molten metal jet and its trapping, (2) dynamic friction between powder particles, and (3) plastic deformation around a void. The microstructure of the shock-compacted powder depends on the range of particle dimensions, which implies that the compaction process based on the above mechanisms is influenced by the powder particle size and its distribution. At the periphery of the sample, two structural features are observed. One, which is characterized by the large melt pool and the marked deformation and breakage of the powder particle, is located near the sample region to which a plane shock wave propagates through the sample capsule. The other shows the long melt band along the bottom and the side of the sample. These features are attributable to a shock wave with a nonuniform shock front and a radial shock wave, respectively.     

Randomized line search techniques in combined GA for discrete sizing optimization of truss structures

This paper presents two randomized line search techniques, each combined with a genetic algorithm (GA), to improve the convergence and the accuracy ratio for discrete sizing optimization of truss structures. The first technique is a simple one-dimensional line search in which design variable axes are selected randomly as search directions. The second is a line search technique whose search direction is determined randomly by fitness function values and differences in the genotypes of individuals. To apply the above-mentioned line search techniques without difficulty, real coding is adopted for discrete problems. The line search techniques are applied to discrete optimization problems of minimum-weight truss structures subjected to stress and displacement constraints. The proposed techniques provide convergence to better solutions than a conventional GA.     

High‐performance MgO thin films for PDPs with a high‐rate sputtering‐deposition process

Abstract— A high‐rate sputtering‐deposition process for MgO thin films for PDP fabrication was recently developed. The deposition rate of the MgO thin film was about 300 nm/min which shows the possibility of production‐line application. The MgO film deposited in this work has a higher density than that of other deposition processes such as electron‐beam deposition and shows good discharge characteristics including firing voltage and discharge formation. These were achieved by controlling the stoichiometry and/or the impurity doping during the sputtering process.     

Selection of Suitable Maximum-heart-rate Formulas for Use with Karvonen Formula to Calculate Exercise Intensity

 The Karvonen formula, which is widely used to estimate exercise intensity, contains maximum heart rate, HR_max, as a variable. This study employed pedaling experiments to assess which of the proposed formulas for calculating HR_max was the most suitable for use with the Karvonen formula. First, two kinds of experiments involving an ergometer were performed: an all-in-one-day experiment that tested eight pedaling loads in one day, and a one-load-per-day experiment that tested one load per day for eight days. A comparison of the data on 7 subjects showed that the all-in-one-day type of experiment was better for assessing HR_max formulas, at least for the load levels tested in our experiments. A statistical analysis of the experimental data on 47 subjects showed two of the HR_max formulas to be suitable for use in the Karvonen formula to estimate exercise intensity for males in their 20 s. In addition, the physical characteristics of a person having the greatest impact on exercise intensity were determined.     

A formal semantics of extended hierarchical state transition matrices using CSP#

The extended hierarchical state transition matrices (EHSTMs) are a table-based modelling language frequently used in industry for specifying behaviours of systems. However, assuring correctness, i.e., having a design satisfy certain desired properties, is a non-trivial task. To address this problem, a model checker dedicated to EHSTMs called Garakabu2 has been developed. However, there is no formal justification for Garakabu2, since its semantics has never been fully formalised. In this paper, we give a formal semantics to EHSTMs by translating them into CSP, Communicating Sequential Processes. Among the variants of CSP, we use CSP#, which is the modelling language used by PAT model checker, as a target of translation. Our semantics covers most of the features supported by Garakabu2. We manually translate the small examples of EHSTMs to CSP#, and verify them by PAT. We also verify the examples directly using Garakabu2 and show that the results are same. The experiments also indicate that verification using our translation and PAT is much faster than that of Garakabu2 in some cases.     

An exploratory study for analyzing interactional processes of group discussion: the case of a focus group interview

The purposes of this study are (a) to establish a measurement for evaluating conversational impressions of group discussions, and (b) to make an exploratory investigation on their interactional processes which may affect to form those impressions. The impression rating and factor analysis undertaken first give us four factors concerning conversational impressions of “focus group interviews (FGIs)”: conversational activeness, conversational sequencing, the attitudes of participants and the relationships of participants. In relation to the factors of conversational activeness and conversational sequencing in particular, the microanalysis of four selected topical scenes from our database further shows that the behavior of the moderator and the interviewees is organized not independently but with reference to each other. The study thus emphasizes the importance of the integration of quantitative and qualitative approaches towards human interactions.

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Design of reduced-order observers for nonlinear sampled-data strict-feedback systems with actuator dynamics and disturbances

We design reduced-order observers for nonlinear sampled-data strict-feedback systems with actuator dynamics and disturbances. First, we use the property of the Euler model of sampled-data systems and the structure of discrete-time observers to design reduced-order observers of the Euler model. Then, we show that the designed observers are semiglobal and practical in T for the exact model. We also give both numerical and practical examples to illustrate the proposed design of reduced-order observers.