A product modeling system for top-down design of machine assembly with kinematic motion

The objective of this research is to develop a product modeling system to support mechanism design from the beginning of the design. The system must cope with two aspects of the design process which are top-down design and preliminary design. The current capabilities of existing CAD and CAE systems are not sufficient to support these two aspects. In this research a modeling method with an abstract model and an incompletely defined model is proposed. The mechanism is presented by constraints and depault values because constraints are suitable for representing the abstract model for a mechanism and default values are useful to supplement an incompletely defined model. We also introduce module-based modeling with mechanism modules corresponding directly to the functionalities of the mechanism and show that it is suitable for top-down design. Incomplete constraints are solved with default values so that the shape and location of the incompletely defined model can be modified and the motion of the model can be simulated. Finally, we illustrate the mechanism modeling system with some examples.     

Zr-Hf interdiffusion in polycrystalline Y2O3-(Zr+Hf)O2

Lattice and grain-boundary interdiffusion coefficients were calculated from the concentration distributions determined for Zr-Hf interdiffusion in polycrystalline 16Y₂O₃·84(Zr_1–x Hf _x )O₂ withx=0.020 and 0.100. The lattice interdiffusion coefficients were described byD=0.031 exp [–391 (kJ mol^–1)/RT] cm² sec^–1 and the grain-boundary diffusion parameters byD=1.5×10^–6exp [–309(kJ mol^–1)/RT] cm³ sec^–1 in the temperature range 1584–2116° C. Comparison of the results with those for the systems CaO-(Zr+Hf)O₂ and MgO-(Zr+Hf)O₂ indicated that the Zr self-diffusion coefficient was insensitive to the dopants in the fluorite-cubic ZrO₂ solid solutions.     

A Gait Phase Measurement System Using Treadmill Motor Current

The article describes the development of a gait phase time-based split-belt treadmill measurement system. Conventional methods of measuring gait phase, such as the foot switch and force plate, require significant preparation and are costly. In this article, we propose a simple, cheap, and accurate gait phase measurement system that utilizes only the treadmill motor current value. Comparison of this algorithm with conventional methods reveals that the proposed algorithm is as accurate as the foot switch. Moreover, the proposed algorithm can estimate stance phase within a 0.2?s error of the measured value of the force plate in most cases (four out of five healthy subjects). This accuracy is higher than that of the foot switch which is widely used in the clinical field.     

Performance analysis of partial response systems for nonreturn-to-zero recording

An analysis is presented of the performance of partial response (PR) systems of types PR(1, 0, 0, . . . , 0, -1) and PR(1, 0, 0, . . . , 0, 1) for nonreturn-to-zero recording. The error probability is obtained as a function of the signal-to-noise ratio (SNR) at the reading point, the phase margin, the linear density, and the roll-off factor of a Nyquist equalizing waveform. Then as a numerical example a performance comparison of the PR systems is made by obtaining the relation between the phase margin and the SNR required to achieve the prescribed error probability.     

Characteristic Instabilities in HfAlO Metal–Insulator–Metal Capacitors Under Constant-Voltage Stress

Time-dependent characteristic changes of metal-insulator-metal (MIM) capacitors with HfAlO dielectric prepared by atomic-layer deposition under constant-voltage stress (CVS) were studied. It was found that relative dielectric constant , dielectric loss , temperature coefficient of capacitance , and frequency coefficient of capacitance gradually increase during CVS testing, whereas the voltage dependence of capacitance weakens. It was also found that changes in -value, , and during CVS testing linearly depend on changes in . These three linear relationships are basically explained by a dielectric-response model proposed for a ldquoflat-lossrdquo dielectric. That is, the increases in -value, , and are attributed to the dielectric-loss increase caused by voltage stress. Stress-time dependence of the dielectric-loss increase is expressed very well by a power function. That is, the power exponent obtained by a curve fitting linearly increases with stress voltage and decreases with increasing aluminum concentration in the HfAlO dielectric. This result indicates that aluminum addition into the HfAlO dielectric can improve the characteristic stabilities of a MIM capacitor under voltage stress.     

Evaluation of additive effects and homogeneity of the starting mixture on the nuclei-growth processes of barium titanate via a solid state route

In an attempt to obtain finest possible microparticles of BaTiO₃ (BT) with highest possible tetragonality via a solid state route, starting mixtures comprising BaCO₃ and TiO₂ were subjected to various pretreatments including addition of glycine and mechanical activation. Reaction processes were monitored by the changes in the weight, crystallinity, and morphology in detail. While mechanical activation with glycine significantly increased the rate of reaction and homogeneity of the particle size of the product, BT, simultaneous particle growth of BT was intolerably acute for micro-electronic devices. The fast particle coarsening was predominated by the coalescence of BT tiny particles formed around titania. A mixture with higher homogeneity was attained by using finer starting materials under wet mixing, avoiding significant mechanical stressing. Particle growth of BT was suppressed to ca. 100 nm to obtain fully crystallized BT particles without significant loss of tetragonality and, hence, close to meet our requirements for MLCCs.     

Heterogeneity of DNA ploidy pattern in carcinoma of the gallbladder: primary and metastatic sites

There are few detailed reports on the heterogeneity of the nuclear DNA ploidy pattern in carcinoma of the gallbladder. We studied twelve autopsied cases who died of extended gallbladder carcinoma. Multiple samples were taken from the primary site (Pri), from direct invasion of the liver (Hinf), from hematogenous metastasis to the liver (H), from lymphatic metastasis (LN) and from peritoneal dissemination (P). The DNA ploidy pattern was investigated by image cytometry. Heterogeneity of the DNA ploidy pattern in Pri, Hinf, H, LN and P was found in 7/11, 2/10, 5/10, 2/6 and 3/6 cases, respectively. Aneuploidy was more frequently found in Hinf than at the Pri. The DNA index of Hinf was significantly higher than that of Pri. Several stemlines, with different quantities of DNA, were found in Pri. Most of these stemlines were also observed in other sites. These facts may suggest that polyclonal cancer cells rather than one cancer cell or monoclonal cancer cells of a Pri metastasize or infiltrate, and that various polyclonal cancer cells proliferate to different degrees under different circumstances.     

ISHIGAKI Retrieval System Using 3D Shape Matching and Combinatorial Optimization

International Journal of Computer Vision - In April 2016, a massive earthquake with a magnitude of 7.3 struck Kumamoto region, Japan, causing major devastation. One of the structures that were...