vol.21 (2008)

Bulletin of Research Center for Computing and Multimedia Studies
Vol.21, 2008 ISSN 1882-7594

A study on the GIS model for the water environment analysis of river basin
- A case of Ashida river basin -

Koji Kodera, Yusuke Nakayama, Yuta Shimizu, Shin-ichi Onodera
Received: February 29, 2008    PDF    Abstract
River basin GIS model whom can be made figure after water environmental information on the entire basin is arranged, and analyzed is necessary for the water environmental conservation, restoration, and management, etc. of the river basin. In this research, it aimed at a new river basin GIS model construction that made the best use of the Unit Basin Value Method for the pollution load analysis, and foreseen attempt was done for the Ashida river basin. As a result, the effectiveness of this technique was able to be shown though a further problem was clarified.
Failure Behavior of Al2O3 by Hypervelocity Impact of Small Particle
Hideaki Minowa, Kazuyoshi Arai, Eiichi Sato, Yasuko Motoyashiki, Sunao Hasegawa
Received: February 29, 2008    PDF    Abstract
The efficiency of a numerical simulation method for elucidating failure behavior of aluminum oxide (Al2O3) caused by a hypervelocity impact of a small particle was investigated. High-velocity impact tests at 1.0 km/s or less using a light gas gun and a hypervelocity impact test at 1.91 km/s using a two-stage light gas gun were conducted. The numerical simulation result of the failure behavior of Al2O3 was compared with the result of the impact test.
Numerical Analysis of Flow within Turbine Cascade with Transpiration Cooling
Yuichi Fushimi, Shimpei Mizuki, Hoshio Tsujita, Toshiyuki Hirano
Received: February 29, 2008    PDF    Abstract
The further improvement of gas turbines requires the development of cooling technique with reduction of cooling air mass flow rate as well as the increase of the turbine inlet temperature. The theoretically most effective air cooling method is the transpiration cooling, which will be expected to reduce the cooling air mass flow rate. In the present study, the two-dimensional flow within the turbine cascade made by the porous media was analyzed numerically by the CFD code. The calculations were performed in order to examine the influence of the porosity of the porous media on the cooling efficiency. The results revealed that the cooling efficiency was strongly influenced by the porosity of porous media.
Numerical Analysis of Flow in Radial Turbine Rotor
Tomoya Komatsu, Gota Nakano, Hoshio Tsujita
Received: February 29, 2008    PDF    Abstract
For the further improvement of the aerodynamic performance of the radial turbine, the detailed investigations for the behavior of the internal flow are required. However, it is very difficult to measure the internal flow by the experimental technique, because the radial turbine is relatively small, and rotates at the high speed. Therefore, the CFD technique is considered to be the effective tool to reveal the internal flow within the rotating radial turbine. In the present study, the flow within the radial turbine was analyzed by the commercial CFD code. The computed results clarified the influences of the 3-dimensional complex flow on the loss generation within the rotating radial turbine.
Hitting Sound Simulation of the Golf Club
Masaki Enomoto, Daiki Taniguchi, Mitsuo Iwahara, Akio Nagamatsu
Received: February 29, 2008    PDF    Abstract
Good sound quality became one of value-added of a golf club. In this study, we made hitting sound prediction program for the purpose of predicting the hitting sound by design stage for attempting cost reduction in product development. In this paper, we describe the result of the utility of the hitting sound prediction program.
Vibration characteristic of Sirocco fan
Tatsuya Yoshida, Shogo Kurihara, Mitsuo Iwahara, Akio Nagamatsu
Received: February 29, 2008    PDF    Abstract
The vibration characteristic of Sirocco fan was examined by Experimental Modal Analysis. In addition, we find vibration characteristics from calculations and elucidate a vibration phenomenon from both sides of experiments and calculations.
The vibration characteristics of badminton racket by modal analysis
Yuta Goto, Kyouhei Terada, Mitsuo Iwahara,Akio Nagamatsu
Received: February 29, 2008    PDF    Abstract
Badminton is very popular sports. However, the badminton racket has not been optimized yet as a sports tool, compared to that for tennis racket. This study is an attempt to investigate the effect of shuttle cock on the vibration characteristics of badminton racket and to clarify the basic vibration characteristics of badminton racket by experimental and theoretical modal analysis
System Identification and Robust Control for Flexible Structures
Masahide Abe, Daiki taniguchi, Mituo Iwahara, Akio Nagamatu
Received: February 29, 2008    PDF    Abstract
This paper deals with a vibration control system for a flexible three-story structure with H-infinity controller and surface bonded PZT (lead zirconium titan ate) patches. The plant transfer function is identified by Time Based Prediction Error Method. As a reference model, plant frequency responses given by Experimental Modal Analysis are used to improve the performance of the identified function. We designed H-infinity robust controller based on the identified plant. We implemented the control system by software and hardware to evaluate the performance. The experiments result in significant decays of two modes with our control system. The decay of first mode is 22 dB and the second mode is 15 dB. And, this system is applied using the finite element method.
Hikaru Honzumi, Yosuke Kataoka
Received: February 29, 2008    PDF    Abstract
We examined electronic structure and atom arrangement in Al2O3-C grain boundaries of alumina-graphite refractory by Molecular Orbital method. Computational results showed it is energetically stable when C atoms set on O atom of O grain boundary in Al2O3, and makes strong bonds with both covalent and ion binding property between O and C atoms. The C atoms bond to O grain boundaries in alumina-graphite refractory.
Folding of Poly ampholytes Using Replica Exchange Monte Carlo Simulations
Yuri Yamada, Yosuke Kataoka
Received: February 29, 2008    PDF    Abstract
We have simulated folding of polyampholytes using replica exchange Monte Carlo method. Polyampholyte (PA) is a chain-like molecule model that consists of charged monomers, like peptides and proteins. We treated some PAs that have several arrangements of charges and chain lengths. In di-block PA, the halves of monomers are positively charged on one side of the chain and the other halves are negatively charged, we obtained two configurations as the most stable structure. One of them, a straight double helix, was obtained in the short chain, and the other, a flat helix, was obtained in the long chain. This change of the most stable structure is mainly caused by the coulomb interaction between the monomers.
Evaporation in Liquid Argon by Constant Volume Molecular Dynamics Simulation
Yosuke Kataoka, Yuri Yamada
Received: February 29, 2008    PDF    Abstract
Evaporation in Liquid Argon is observed by Constant Volume Molecular Dynamics Simulation. The molecular interaction potential energy is Lennard-Jones function. The initial configuration has the liquid part and the gas part which is empty. The NEV simulations and the NTV ones give the same thermodynamic properties and the self-diffusion coefficient. The number of the molecules in the unit cell is 108 or 256. The optimum configuration is searched for easy observation on the evaporation by the personal computer.
Phase Transitions in Proton Ordered Ice under Pressure by Molecular Dynamics Simulations
Yosuke Kataoka, Yuri Yamada
Received: February 29, 2008    PDF    Abstract
The proton ordered ice structures are obtained by NTV molecular dynamics simulations on the basic cells with small number of molecules at temperature T = IK. The model potential is Jorgensen’s TIP4P. Many NTp molecular dynamics simulations are performed to obtain enthalpy as a function of pressure for each ice structure. Phase transition pressures are estimated at low temperature T = IK in the proton ordered ice. Ice Ih, ice II and ice VIII are found stable at this temperature, although the extra ice IV appeared in the present work.
Restoration of Reconstructed Images in the Advanced Compton Camera
Takeshi Kurihara, Koichi Ogawa
Received: February 29, 2008    PDF    Abstract
An advanced Compton camera (ACC) enables us to reconstruct the distribution of gamma-ray sources without a mechanical collimator. For this ACC we have proposed a method with a more efficient algorithm than that of a conventional Compton camera. However, our method may introduce significant blurring if there are measurement error in detecting gamma-rays and electrons. To remove the blurring in a reconstructed image we assumed the system as a shift-invariant three dimensional system and used a parametric Wiener filter. The validity of our proposed method was confirmed with the simulations.
A Method of Visualization for Displacement Currents in Capacitos
Kenji Hoshino, Yoshifuru Saito
Received: February 29, 2008    PDF    Abstract
Electrical capacitor is one of the most popular and widely used electric circuit elements storing electric field energy. Due to its mechanical structure, electric field distribution could not uniform at the edges of electrode plates constructing capacitor. This field distortion is so called edge effect. Principal purpose of this paper is to minimize the edge effect, so that it enables us to optimize the shape of electrodes leading to the maximum capacitance but minimum size. To realize this purpose, it is essential to compute the electric fields around capacitor exactly. The electric fields around the capacitor distribute to an infinitely long distance point theoretically. In order to take into account this electric field nature rigorously, in this paper, we employ the strategic dual image (SDI) method along with conventional first order triangular finite element method.
Visualization of High Frequency Current Distribution By Semi-analytical Method
Kohei KURODA, Yoshifuru SAITO
Received: February 29, 2008    PDF    Abstract
To visualize the electromagnetic fields, we have previously proposed a semi-analytical method, which has made it possible to simulate the complex electromagnetic field distributions not obtain by the conventional numerical schemes, such as finite elements and boundary elements means. Distinguished superior point of our semi-analytical method is that our semi-analytical method is only one way solving for the electromagnetic field, conducting and displacement currents simultaneously In this paper, we propose a new semi-analytical approach to visualize the eddy current distribution in a two-dimensional plate, Successful result of this computation promises that eddy current testing maybe carried out taking into account the displacement current, i.e., capacitive, effects.
Ferriresibabce Circuit Analysis Employing Chua Type Model
Keisuke Matsuo, Yoshifuru Saito
Received: February 29, 2008    PDF    Abstract
This paper studies nonlinear phenomena caused by ferromagnetic materials. To represent nonlinear properties of ferromagnetic materials used in the electrical transformer, we employ a Chua-type magnetization model composed of the nonlinear parameters: permeability μ, reversible permeability μr, and hysteresis parameter s independently measured from the past magnetization history. By the backward Euler method with automatic modification, the transient analysis of this initial value problem is carried out. As a result, it is clarified that ferroresonance phenomenon could be observe secondary circuit of transformer. Moreover, computed transient response is well corresponding to measured one.
A study of 1/f fluctuation
Soh MIYASAKA, Takashi SUNAGA, Yoshifuru SAITO , Chieko KATOH
Received: February 29, 2008    PDF    Abstract
1/f fluctuation analysis of the non-life”bearing, life-bearing and self driven particle targets is carried out. As a result, it is clarified the followings. State transition, e.g., melting an ice to water, of all the non-life-bearing targets exhibits 1/f fluctuation frequency characteristics. Namely, all the non-life-bearing materials exhibit 1/f fluctuations when changing their state aspect such as solid, liquid and gas. On the other side, 1/f fluctuations can be observed the creative works, e.g., artistic paints when transitioning mental situation from depression to mania of life-bearing target, i.e., his or her. In the other words, a life-bearing target typically human exhibits 1/f fluctuation characteristics via his own creative work when changing his mental situation.
Iron Loss Distribution Visualization in Magnetic Domain Images by the Bitter Method
Takashi SUNAGA
Received: February 29, 2008    PDF    Abstract
The Bitter method is most commonly observing way of the magnetic domains situation even though it is possible to observe only the surface of specimen. Applying magnetic field to this magnetic material covered by magnetic fluid makes it possible to observe the magnetic domain dynamics by a microscope. This paper reveals that the parts exhibiting 1/f fluctuation frequency characteristic give high the iron loss while not exhibiting 1/f fluctuation parts, i.e. containing much silicon, give low iron loss. Thus, it is revealed that the mixture rate of iron and silicon determines the optimal silicon steel composing most of the electrical machines.
Defect Visualization by Transient Thermal Distributions by Dynamic Infrared Image
Goh SUZUKI, Yoshifuru SAITO
Received: February 29, 2008    PDF    Abstract
In order to realize the reliable inspecting systems, many infrared image sensors are utilized because of their high visual capability not depending on the human visible light condition. Recently, nuclear electric power plant is increasing its usefulness not warm up entire earth system accompanying with human life activity. We are now planning to enhance the infrared inspecting system to carry out the condition based maintenance methodology for nuclear electric power plant. At first, this paper clarifies a relationship between the pixel values constructing infrared image and absolute temperature even though automatic gain control function equipped in infrared CCD camera is activating to get the highest contrast image. Second we demonstrate the absolute temperature visualization, which is the most important inspecting factor in the nuclear power plant, on the bended iron sheet.
A study on Optimization of Wave Transmitting Boundary
Shinji Ino, Shinobu Furuya, Nagayuki Yoshida
Received: February 29, 2008    PDF    Abstract
When analyzing the wave propagation problem in the infinite or semi-infinite elastic body, the numerical device which can transmit the outgoing waves should be attached to the boundary of the finite analytical region. Several objective functions are proposed to find out the optimal property of boundary coefficients. Optimization is performed by genetic algorithm. By evaluating a lot of numerical results on finite bars, the vibration energy function is chosen as the best.
A Study on Infinitesimal Element Model And Nonlinear Analytical Method
Masayuki Hatakeyama, Junpei Yasukawa, Nagayuki Yoshida
Received: February 29, 2008    PDF    Abstract
We need to analyze the fracture phenomena due to the disasters such as earthquakes. Because we can not derive the exact result in detail by the analytical method for the continuum, we take a new physical approach based on the infinitesimal element model. By this model, we can analyze the whole domain of deformation from an elastic continuity to the plastic deformation until the structures are totally divided into particles. We simulate nonlinear behavior of concrete structures by this method.
Linear and Nonlinear Dynamic Analysis of Open Branched Structure
Motonori Nishikawa, Hiroo Miura, Atsushi Watanabe, Nagayuki Yoshida
Received: February 29, 2008    PDF    Abstract
This research defines the structure that could be seen in the upper part of the trees and their roots, as the open branched structure. Its structural property is investigated by ordinary analytical method including linear and non-linear dynamics through a very interesting simulation for the growth of trees which is based on the bibliographic search to other fields such as botany Its aim is to make clear the secret of the earthquake-resistance characteristics of trees from the viewpoint of the structural engineering, and also to find out the useful information for the future of architectural structures.
Dynamic Analysis for the Behavior of Particle model
Chisato Shimoyama, Asuka Miyazaki, Nagayuki Yoshida
Received: February 29, 2008    PDF    Abstract
This paper simulates the behavior of collapse by the particle model analysis. The landslide and liquefaction of the soil have been studied by the distinct element method. This method usually uses the circular element as the judgment for contact is not so complex, while there is the problem that the circular element more rotates than actual particles. Therefore, we propose some method to resolve these problems.
Discrete Analysis for Plate Bending Problems by Using Hybrid-type Penalty Method
Anna V. Varclanyan, Norio Takeuchi
Received: February 28, 2008    PDF    Abstract
In present paper, we have given investigation of the plate bending problem by numerical treatment using hybrid-type penalty method (HPM) based on discontinuous Galerkin method. The HPM assume linear and nonlinear displacement field with rigid displacement, rigid rotation, strain and its gradient in each subdomain and introduce subsidiary condition about the continuity of displacement into the framework of the variational expression with Lagrange multipliers. For this purpose, we accept the Kirchhoff theory, which takes no into account the transversal shear deformation. In first step of the work, we give the equilibrium equations for deformable body in 3D case and as boundary conditions we give geometrical (for displacement field) and kinetic (for surface force) boundary conditions. Secondary we apply Kirchhoff theory to make the displacement field for plate bending problem into the 3D case. For this purpose, we use quadratic form, which includes rigid, linear, and nonlinear parts of displacements. It can define the parameters used in this displacement field as each subdomain independently. We introduce penalty function, which presents strong spring connecting each subdomain. Then we obtain stiffness matrix as every contact surface of each subdomain. The discretization equation of this model becomes a simulteniuos linear equation. The coefficient matrix consists of stiffness in the sub-domain and subsidiary condition on the intersection boundary for the adjacent sub-domain. In this model, it can express the discontinuous phenomenon of hinge etc. without changing degree of freedom. Finally, we compute simple problems to check the accuracy of the elastic solution.
Utilization of IC card on Distance Education
Norimichi Ishida
Received: February 6, 2008    PDF    Abstract
Distance education (distance learning) take on an increasingly important role in education filed from this time. Issue of last report, we were made known that IC card is effective functional capability for class-attendance control system with distance education. We made IC card by lecturer’s request again. This system is organized HICA(Hosei Intelligent Card) attached IC-tag and handy-type IC reader. Making card in this time, we attached face-image of student who take the course for certification immediately.