Sensitivity analysis and its application for dynamic improvement

In order to determine appropriate points where natural frequency or mode shape under consideration can be effectively modified by structural modification, the theoretical background of sensitivity analysis is described, followed by experimental verification with a simple structure. Then it can be extended to (1) operational deflection shape, where a problem arises at offresonance frequency, (2) relative motion, (3) transmitted force through connecting points between components, (4) servo system, which consists of electrical elements with mechanical elements, and (5) acoustics generated by the vibration of the structure. To illusrate its effectiveness, many actual examples are given.     

Public Organizations in an Emergency: The 1995 Hanshin‐Awaji Earthquake and Municipal Government

A magnitude 7.2 earthquake hit one of the major metropolitan areas of Japan at 5:46 am on 17 January 1995. This paper examines the behaviour of public organizations during this event in four municipal governments. Opening and managing shelters, reception of relief goods and cooperation with volunteers are, especially, studied in detail. Some of the programmes implemented by the national government and Hyogo prefectural government are also studied. Based on these studies, characteristics of the organizations' responses during the emergency are analyzed. It is argued that the structure of organizations or the disaster response programmes are formulated or changed by using more stable structures or procedures.     

DEVELOPMENT OF DIRECT UPGRADING PROCESS FOR HEAVY CRUDE OIL

The direct upgrading process from heavy crude oil to sweet and light oil (IKC process) has been developed for about 10 years in Idemitsu Kosan. Compared with conventional refinery scheme consisting of YR-HDS, VGOHYC and so on, the new refinery scheme combined with IKC process and Topper was always economically feasible with lower cost and smaller energy consumption. In the existing refinery of no middle distillate HDS and residue HDS of HYC plants to supplement IKC process is expected to be one of the efficient methods to cope with the environmental regulations.     

Generation of linearly polarized transition radiation X-ray beam

We have successfully produced almost linearly polarized X-ray beam by extracting Transition Radiation (TR) X-rays through a rectangular slit 3 mrad long and 0.2 mrad wide placed downstream of a 7.5-μm thick Kapton foil stack radiator bombarded with a 1-GeV electron beam. Our calculation predicted that the linearity of TR photon was 94% for both a vertical and a horizontal slit. The measured results for the vertical slit agreed with the calculation, and the linearity of obtained TR X-ray beam was more than 90%. For the horizontal slit, the measured results differed from our expectations due to a prolonged electron beam profile. In the polarization measurement of TR photon we used the Bragg reflection on a lithium fluoride crystal [LiF(200)] which acted as both a polarimeter and a spectrometer.     

Re‐ignition surge and high‐frequency arc extinction phenomena at 550‐kV shunt reactor current interruption

At substations connected with transmission lines and cables, shunt reactors are sometimes installed to compensate the capacitive current of these lines and cables. It is known that re‐ignitions occur and high‐frequency currents flow during interruption of the shunt reactor currents by switches. When the high‐frequency currents are interrupted immediately after the re‐ignitions (which is called high‐frequency arc extinction), the result is often repetitive re‐ignitions or voltage escalations that produce dangerous overvoltages. The authors investigated the occurrence of high‐frequency arc extinctions in a 550‐kV one‐break SF₆ gas circuit breaker during interruption of a 550‐kV shunt reactor current. Computations for a real 550‐kV substation gave a minimum frequency of 290 kHz for the high‐frequency current. However, 550‐kV reactor current interruption tests showed that high‐frequency arc extinctions did not occur even when this frequency was lowered to 26 kHz. Since high‐frequency arc extinction is generally likely to occur at lower frequencies, it was concluded that high‐frequency arc extinction will not occur in a 550‐kV one‐break SF₆ gas circuit breaker during interruption of shunt reactor current in real substations. © 2001 Scripta Technica, Electr Eng Jpn, 136(2): 18–25, 2001     

Facilitating children's proportional reasoning: A model of reasoning processes and effects of intervention on strategy change.

In this study, 140 fourth graders were asked to solve proportion problems about juice-mixing situations both before and after an intervention that used a manipulative model or other materials in 3 experiments. Using a manipulative model based on children's prior knowledge about crowdedness and equal distribution was effective in letting children discover a unit strategy, which was useful for solving proportion problems. The model was more effective for those who had an appropriate representation but could not correctly compare juice concentrations than it was for those who didn't have the representation. On the basis of this study, different approaches appear to be necessary to facilitate children's proportional reasoning, depending on the reasoning process (representation or comparison) with which children are having difficulty. Interventions on the basis of the process model and learning that builds on intuitive knowledge are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Defect-Tolerance in Cellular Nanocomputers

For the manufacturing of computers built by nanotechnology, defects are expected to be a major problem. This paper explores this issue for nanocomputers based on cellular automata. Known for their regular structure, such architectures promise cost-effective manufacturing based on molecular self-organization. We show how a cellular automaton can detect defects in a self-contained way, and how it configures circuits on its cells while avoiding the defects. The employed cellular automaton is asynchronous, i.e., it does not require a central clock to synchronize the updates of its cells. This mode of timing is especially suitable for the high integration densities of nanotechnology implementations, since it potentially causes less heat dissipation.

Nanocolloid cake properties determined from step‐up pressure filtration with single‐stage reduction in filtration area

A sophisticated method was developed for evaluating simultaneously and accurately both the average specific resistance and average porosity of the filter cake formed in unstirred dead‐end ultrafiltration of nanocolloids such as protein solution and nanosilica sol. In the method, a step‐up pressure filtration test was conducted by using a filter with a single‐stage reduction in the effective filtration area. The influence of the pressure drop across the cake on not only the average specific cake resistance but also on the average cake porosity of highly compressible filter cake was evaluated using only flux decline data in one dead‐end filtration test, taking advantage of the decrease in the cake thickness caused by the pressure increase. As a result, the cake properties were easily determined for a variety of nanocolloids. Constant pressure dead‐end ultrafiltration data obtained under various pressures and concentrations were well evaluated based on the method proposed. © 2015 American Institute of Chemical Engineers AIChE J, 61: 4426–4436, 2015     

A two-variable silicon neuron circuit based on the Izhikevich model

The silicon neuron is an analog electronic circuit that reproduces the dynamics of a neuron. It is a useful element for artificial neural networks that work in real time. Silicon neuron circuits have to be simple, and at the same time they must be able to realize rich neuronal dynamics in order to reproduce the various activities of neural networks with compact, low-power consumption, and an easy-to-configure circuit. We have been developing a silicon neuron circuit based on the Izhikevich model, which has rich dynamics in spite of its simplicity. In our previous work, we proposed a simple silicon neuron circuit with low power consumption by reconstructing the mathematical structure in the Izhikevich model using an analog electronic circuit. In this article, we propose an improved circuit in which all of the MOSFETs are operated in the sub-threshold region.     

Automated Verification of Functional Correctness of Race-Free GPU Programs

We study an automated verification method for functional correctness of parallel programs running on graphics processing units (GPUs). Our method is based on Kojima and Igarashi’s Hoare logic for GPU programs. Our algorithm generates verification conditions (VCs) from a program annotated by specifications and loop invariants, and passes them to off-the-shelf SMT solvers. It is often impossible, however, to solve naively generated VCs in reasonable time. A main difficulty stems from quantifiers over threads due to the parallel nature of GPU programs. To overcome this difficulty, we additionally apply several transformations to simplify VCs before calling SMT solvers. Our implementation successfully verifies correctness of several GPU programs, including matrix multiplication optimized by using shared memory. In contrast to many existing verification tools for GPU programs, our verifier succeeds in verifying fully parameterized programs: parameters such as the number of threads and the sizes of matrices are all symbolic. We empirically confirm that our simplification heuristics is highly effective for improving efficiency of the verification procedure.