International Journal of Applied Electromagnetics and Mechanics - Volume 15, issue 1-4

Authors: Mukhopadhyay, S.C. | Yamada, S. | Iwahara, M.

Article Type: Research Article

Abstract: This paper has investigated the possibility of applying nondestructive evaluation technique for finding the defects in electroplated materials. Planar meander and mesh type magnetic sensors have been considered and their relative performance have been compared based on a single criterion that the effective area of the material surface covered by each type of sensor is same.

DOI: 10.3233/JAE-2002-461

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 323-329, 2002

Authors: Kohno, H. | Watanabe, K. | Nomura, Y. | Saito, M.

Article Type: Research Article

Abstract: The component of ITER facing directly to plasma is called the first wall. The first wall is composed of DSCu/SS316 HIP bonded structure. In addition to residual stress due to the HIP bonding process the electromagnetic force is loaded on the first wall during plasma disruption. In this study, we assume an initial crack in the first wall. Stress induced by the electromagnetic force at the crack tip is estimated by finite element method taking the …residual stress into consideration. From a viewpoint of fracture mechanics, stress intensity factor K is evaluated to make sure the structural integrity of the DSCu/SS316 HIP bonded structure. As a result of analyses, the stress intensity factor K is not so large for all of the assumed cracks. Therefore, there is no possibility of fracture due to the crack growth during the lifetime of the first wall. Show more

DOI: 10.3233/JAE-2002-469

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 331-336, 2002

Authors: Endo, Hisashi | Saito, Yoshifuru

Article Type: Research Article

Abstract: This paper introduces a novel approach of visualization for electromagnetic fields. Our approach is one of the image analysis methodologies based on the classical field theory, which has versatile capability for image processing, compressing, visualizing, identifying, and animating. A key idea is that each of the pixels representing a digital image is regarded as a kind of potentials in vector fields. Gradient or curl operation of the vector calculus to the image data yields image field …vector distribution. Any kinds of images can be represented by well-known partial differential equations. The Poisson and Helmholtz types of equations are possible to represent the static and dynamic images, respectively. In this paper, visualized electromagnetic field images are analyzed based on our image differential equations. The image Poisson equation is possible to reconstruct the original electromagnetic fields with high spatial resolution. The image Helmholtz equation enables us extr action of the parameters characterizing the electromagnetic phenomena. Show more

DOI: 10.3233/JAE-2002-485

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 337-342, 2002

Authors: Senoo, Isamu | Saito, Yoshifuru | Hayano, Seiji

Article Type: Research Article

Abstract: We have been proposing the image processing methodology where the human voice signals are transformed into the three-dimensional image data by means of the three-dimensional Lissajous diagram [1]. In this paper, we apply the image cognition technology to the cognition of the magnetic sensor signals. At first, the time domain signals are converted into the three-dimensional images, which construct the database system. Secondly, when we measure a time domain signal, this signal is also converted into …a three-dimensional image. This three-dimensional image becomes an input vector of a least squares means. Least squares solution gives a composite signal as a linearly combined database signals. Extracting the most dominant term from the least squares solution reveals the cognized signal. Thus, we have succeeded in the time domain magnetic sensor signal cognition by means of the image cognitive technology [2]. Show more

DOI: 10.3233/JAE-2002-475

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 343-347, 2002

Authors: Shigeta, Yukiyasu | Hayano, Seiji | Saito, Yoshifuru

Article Type: Research Article

Abstract: In the present paper, we propose a method of analysis for the magnetic sensor signals. Based on the physical characteristic value such as a time constant of the electric circuits, our methodology tries to work out an equivalent characteristic value reflecting the physical property of the target metallic material [1,2,3]. Our smart magnetic sensor developing is to recognize a datum from the signal database. This is applied to the space domain signal cognition. As a result, …this paper reports that the equivalent characteristic value is an extremely useful quantity in order to examine the physical nature of the target. Show more

DOI: 10.3233/JAE-2002-479

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 349-352, 2002

Authors: Watazawa, Yasuyuki | Hayano, Seiji | Saito, Yoshifuru

Article Type: Research Article

Abstract: Any of the numerical methods for electromagnetic field analysis essentially require a subdivision of a problem region. By notifying this subdivision, we have previously proposed a new methodology by applying the analytical solution to each of the discretized parts. The first trial of this semi-analytical electromagnetic filed computational methodology has made it possible to simulate the complex electromagnetic field distributions not obtainable by the conventional numerical schemes, such as finite and boundary …elements means. However, our semi-analytical method encounters some difficulty when analyzing the high frequency electromagnetic field distributions because of the displacement currents.In the present paper, we propose a new semi-analytical approach taking the displacement currents into account to overcome this difficulty. Show more

DOI: 10.3233/JAE-2002-473

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 353-357, 2002

Authors: Kato, Chieko | Endo, Hisashi | Saito, Yoshifuru | Horii, Kiyoshi

Article Type: Research Article

Abstract: A new computer-aided method, based on Saito's Fourier-wavelet theory, is used to extract the facial expressions that appear and disappear in less than one-fifth of a second, i.e. expressions that reveal the true emotions of a human being. The new method consists of two major steps. The first step is the application of the Fourier transform to reduce the spatial phase differences between the reference and test images. The second is the application of the wavelet …transform to extract the local discontinuous differences. This method is applied to the moving images in the interview scene. Using this method, the difference between the two facial expressions has been extracted, even though both images differ in their size and reference position. Show more

DOI: 10.3233/JAE-2002-481

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 359-364, 2002

Authors: Ema, Akira | Hayano, Seiji | Saito, Yoshifuru

Article Type: Research Article

Abstract: In the present paper, we propose the methodologies in order to realize the desired magnetic field distributions by using single-sided exciting coils. As a result, it is revealed that a combination of the least squares and the generalized vector sampled pattern matching method suggests the practically realizable exciting coil layout.

DOI: 10.3233/JAE-2002-478

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 365-370, 2002

Authors: Morohoshi, Noriko | Endo, Hisashi | Saito, Yoshifuru | Horii, Kiyoshi

Article Type: Research Article

Abstract: When reading a novel by EKUNI Kaori, reader's world in the brain has been clarified by means of the discrete wavelet analysis. According to the analysis, reader's world in the brain has been classified into two layers. One is the world in the book and the other is the existing real world. Major target of this paper is to visualize the transition states between two layers. As a result of our analysis, it has been revealed that the wavelet multi-resolution …analysis has made it possible to visualize the transition states as well as to clarify the composing methodology of the novel. Show more

DOI: 10.3233/JAE-2002-480

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 371-375, 2002

Authors: Naruta, T. | Endo, H. | Hayano, S. | Saito, Y.

Article Type: Research Article

Abstract: In order to design an optimal planar inductor, this paper carries out several axisymmetrical magnetic field simulations fully taking the magnetic hysteretic properties of ferromagnetic core materials as well as open boundary condition into account. Finite element method is applied to evaluating the magnetic fields, reactive and dissipative energies in a planar inductor. Because of the nature of magnetic fields, it is essentially taken into account the open boundary effects to evaluate the exact characteristics of …planar inductor. Since the finite elements is one of the methodologies to solving for the partial differential equations, and then it has been difficult to take the open boundary effects into account. However, this paper removes this difficulty by employing the strategic dual image (SDI, in short) method [1,2]. Another difficulty is caused by the hysteretic magnetization characteristics of magnetic core materials. Applying the Chua type magnetization model to represent the hysteretic property also removes this difficulty. As a result, it is revealed that the frequency characteristic of core magnetic materials as well as shape dominate major characteristics of the magnetic fields, reactive and dissipative energies in the inductors. Show more

DOI: 10.3233/JAE-2002-477

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 15, no. 1-4, pp. 377-382, 2002