巻号一覧
34 巻, 5 号
選択された号の論文の14件中1～14を表示しています
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高野 英彦1998 年 34 巻 5 号 p. 347-352
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリー“Flexible Virtual Reality application Technology for Product Design (FVRD)”Project has been planned. The purpose of this project is to apply the virtual reality technology for a product design such as a machine parts and a electric parts. This paper deals with a method for present a virtual object as precisely as real position to a operator. Therefore, firstly theoretical analysis concerning to a visibility and positinal error of a virtual object are executed. Secondly, evaluation function considering both visibility and positinal error is proposed and calculated by the computer simulation. Finally, experiments by human operator are executed in a positional error. And, these calculated and experimental results are fairly coincident. And, the conclusion is that the parameter of De and Ds is better to set equal for the image presentation using parallax.抄録全体を表示PDF形式でダウンロード (1360K) -
山田 英巳, 有福 智之, 古賀 和利1998 年 34 巻 5 号 p. 353-359
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーIn the image velocimetry, it is generally required to detect the various velocity in each position of the flow field. But the maximum velocity which the usual velocimetry can detect has been limited in about 1 pixel per frame. Then, in order to measure the wide range of velocity vectors from the dynamic image, the improvement of performance in the image velocimetry based on a spatio-temporal correlation method would be attempted by enlarging the analytical region and by interpolating the new frame. The analytical performance of velocimetry was estimated by measuring the velocity from the flow dynamic image made artificially on the personal computer so as to simulate the flow of fluid containing a lot of small particles. As the results, the velocity range of the improved velocimetry became larger than that of the usual velocimetry.抄録全体を表示PDF形式でダウンロード (2269K) -
山野 正樹1998 年 34 巻 5 号 p. 360-367
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーFor Quantitative Nondestructive Evaluation with ultrasound, a new approach to ultrasonic image reconstruction has been proposed and compared with Synthetic Aperture Focusing Technique (SAFT) and Wiener filtering in terms of the spatial resolution and the image quality of defects. The new approach, whose algorithm was based on depth-invariant defect image of SAFT results, was better in the spatial resolution than SAFT and comparable to Wiener filtering. And it's more useful in ultrasonic NDE applications than Wiener filtering because of requiring only one point spread function (PSF), while in Wiener filtering signals from defects having different depths must be restored with different PSFs. A disadvantage of this technique was that the reconstructed image has a relatively lower image quality, which may cause incorrect evaluation of defects.抄録全体を表示PDF形式でダウンロード (2984K) -
小菅 義夫, 亀田 洋志, 真野 清司1998 年 34 巻 5 号 p. 368-375
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーModern signal processing techniques such as in air traffic control can provide both position and range rate measurements. In this paper, the relationship of the fully coupled filter (a six-state filter) and the decoupled filter (three two-state filters) for radar tracking using extended Kalman filter with range rate measurements is presented. The computational requirements of the complex fully coupled filter are inconsistent with the available computational resources and the numbers of targets desired to be tracked. Therefore, a simple decoupled filter is necessary. In order to represent a mathematical model of the target motion, we use the NEU (North-East-Up) coordinates, which are inertial Cartesian coordinates, for they are convenient for target trajectory extrapolation. Target prediction (state estimate extrapolation) is also carried out in the NEU coordinates. Target updating (state estimate update) is carried out in the rotational Cartesian coordinates which are aligned with the predicted target line-of-sight. Approximately, the decoupled filter is equivalent to the fully coupled filter when the rotation of the coordinates can be neglected, the target angular velocity is almost equal to zero and the plant noise covariance matrix is diagonal where all elements on the diagonal are equal. As a result, the decoupled filter nearly equals the fully coupled filter in tracking accuracy when the target velocity is low, the target range is long, or the target flies straight on toward a radar.抄録全体を表示PDF形式でダウンロード (1584K) -
藤本 健治, 杉江 俊治1998 年 34 巻 5 号 p. 376-383
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーThis paper is concerned with Youla-Kucera parameterization for a class of nonlinear systems via kernel representations. Kernel representations are generalized left factorizations for nonlinear systems which are introduced by Paice et. al. We give a rather natural generalization of Youla-Kucera parameterization by using observer based kernel representations. Furthermore we derive the state space formula of the parameterization in this framework.抄録全体を表示PDF形式でダウンロード (1911K) -
Paulo S.A. WANGHAM, 美多 勉1998 年 34 巻 5 号 p. 384-392
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーThis paper solves a spectral factorization problem for a rectangular transfer function with infinite and imaginary axis zeros. And the result is used to solve the singular inner-outer factorization problem.抄録全体を表示PDF形式でダウンロード (1643K) -
熊本 博光, 坂元 一郎, 天目 健二, 下浦 弘1998 年 34 巻 5 号 p. 393-399
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーThis paper develops a reduced-dimension sliding mode controller for steering of a constant speed vehicle. First, a non-linear vehicle is linearized and a 5-dimension state equation consisting of vehicle angle, yaw rate, side slip angle, lateral position, and lateral speed is obtained. A headway viewpoint is introduced to define a lateral error. A 2-dimension sliding mode controller is then derived on a phase plane representing the lateral error and its derivative. Two cases are considered: 1) vehicle parameters are known, and 2) cornering force parameters are unknown. The dimension reduction is justified for the two cases, and the phase plane trajectory is shown to converge to the origin by bounded steering. An important role of a specific headway viewpoint is emphasized for the unknown parameter case. Computer simulations for a non-linear vehicle include a reverse-steering on a packed snow road, and demonstrate a good performance of the proposed controller.抄録全体を表示PDF形式でダウンロード (1503K) -
田沼 正也, 沖村 仁志, 芝田 健二, 川瀬 隆世1998 年 34 巻 5 号 p. 400-407
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーFor stable computation of stiff plant model carrying both of quick and slow dynamics, a graph oriented approach to analysis of nonlinear block diagram is developed. Since this method can generate the minimum order computational model from complicated block diagram by simple procedure, stable dynamic simulation using implicit formula can be put to practical use. In addition, it can produce computational models for transient analysis and steady state analysis, and linear state model in unified scheme. Using the proposed method, the simulator Xsim which provides interpreter generating data of block diagram from mathematical equations and user defined function, analysis functions, and output functions displaying trend graph and making a text file of linear state space model for MATLAB, has been manufactured experimentally. By simulation of once through sliding pressure boiler using high order model, validity of the proposed method is established.抄録全体を表示PDF形式でダウンロード (2001K) -
久保田 直行, 福田 敏男1998 年 34 巻 5 号 p. 408-414
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーThis paper deals with virus evolutionary genetic algorithm. The genetic algorithms (GAs) have been demonstrated its effectiveness in optimization problems in these days. In general, the GAs simulate the survival of fittest by natural selection and the heredity of the Darwin's theory of evolution. However, some types of evolutionary hypotheses such as neutral theory of molecular evolution, Imanishi's evolutionary theory, serial symbiosis theory, and virus theory of evolution, have been proposed in addition to the Darwinism. Virus theory of evolution is based on the view that the virus transduction is a key mechanism for transporting segments of DNA across species. This paper proposes genetic algorithm based on the virus theory of evolution (VE-GA), which has two types of populations: host population and virus population. The VE-GA is composed of genetic operators and virus operators such as reverse transcription and incorporation. The reverse transcription operator transcribes virus genes on the chromosome of host individual and the incorporation operator creates new genotype of virus from host individual. These operators by virus population make it possible to transmit segment of DNA between individuals in the host population. Therefore, the VE-GA realizes not only vertical but also horizontal propagation of genetic information. Further, the VE-GA is applied to the traveling salesman problem in order to show the effectiveness.抄録全体を表示PDF形式でダウンロード (2143K) -
伊藤 誠, 稲垣 敏之1998 年 34 巻 5 号 p. 415-421
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーThis paper discusses how beliefs of a decision maker can be revised for the safety control of a large-complex plant via Dempster-Shafer theory. In this paper, we examine the following two methods for belief revision: (i) combination rules for basic probability assignments, and (ii) updating rules based on the conditioning of belief functions. We give, for each case, an optimal rule for minimizing the expected loss caused by actions of a decision maker who adopts a mixed strategy for safety control, where the decision maker's safety-control is probabilistic over policies of the safety-preservation type and the fault-warning type. We clarify the following two points: (1) An optimal rule of combination cannot be determined until the exact time moment of combining information, because the optimality depends on a mixed strategy adopted by the decision maker and information items obtained to be combined. (2) An optimal rule of updating can be specified in advance, irrespective of a decision maker's mixed strategy or information items to be obtained. These two points show an essential difference between the combination rules and the updating rules: The optimal combination rule has a dynamic nature, while the optimal updating rule has a static aspect.抄録全体を表示PDF形式でダウンロード (1531K) -
亀山 嘉正, 倉重 賢治, 大倉 輝, 林 篤裕, 佐山 隼敏, 宮崎 茂次1998 年 34 巻 5 号 p. 422-429
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーFTA (Fault Tree Analysis) is used for reliability and safety analysis of system. In FTA, the critical importance is defined in order to control occurrence of top event effectively. In the case of consideration in two or more top events, it can be enough expected to the fault tree about top events that common fundamental events are contained. In this paper, we have proposed a method to estimate for critical importance synthetically for several fault trees. Furthermore, this method is applied to reliability analysis of small engine. Consequently, the priority which improve fundamental events contained in these fault trees become clear.抄録全体を表示PDF形式でダウンロード (2777K) -
江村 暁, 舘 〓1998 年 34 巻 5 号 p. 430-437
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーTactile sensing has received an increasing amount of attention since 1980s, and some works for the detection of a target shape through contact point sensing from tactile and proprioceptive information have been done. However, all of them are based on the assumption that the target is static and rigid. In this paper, we derive the relation between the motion of the target object and the changes of contact oval parameters, and analyze the conditions for estimating the motion of the target object. On the numerical verification of regularity of this relation for a target model, it is shown that the change of tactile images and the relative velocity on two sites are enough for estimating the motion, compliance, and curvature of the target object.抄録全体を表示PDF形式でダウンロード (1550K) -
向井 利春, 大西 昇1998 年 34 巻 5 号 p. 438-444
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーThe recovery of the three-dimensional motion parameters and structure of an object from its perspectively projected two-dimensional dynamic picture image is one of the most important problems in computer vision. Previous works on shape and motion from optical flow have been unsatisfactory because they require solving nonlinear simultaneous equations using iterative search. In the present paper, we propose a method for recovering motion and structure from perspectively projected optical flow of feature points which move rigidly. In order to simplify the computation and obtain clear perspectives, we adopt a spherical image screen and arrange equations in linear form. As a result, our method does not require the solution of nonlinear simultaneous equations, but only requires the solution of linear ones. In addition, the uniqueness of the solution is guaranteed. Furthermore, we propose a reliability measure of the recovery. Simulation results of our method are also presented.抄録全体を表示PDF形式でダウンロード (1599K) -
阿刀田 央一, 中村 雄一, 冨澤 眞樹, 横山 一也, 今田 忠博1998 年 34 巻 5 号 p. 445-453
発行日: 1998/05/31
公開日: 2009/03/27
ジャーナル フリーMagnetic motion capture is an instrument which acquires three dimensional position and orientation of magnetic sensors through several time-shared magnetic field vectors from differently exited transmitter coils. Many small sensors could be attached to pin-points of a moving object including human body to record its motion. Tracking problem in pictorial motion picture will be avoided. Apart from Polhemus's which inherently depends on three orthogonal concentric transmitter coils, various coil arrangements could be devised according to the shape and dimension of required sensing volume. We define design of that instrument as an inversion-based problem and discuss on a solving procedure in which arrangement of coils and excitation pattern could be determined heuristically and almost independently of inversion algorithm since proposed algorithm is rather general to various field distributions. The algorithm starts from selected rotation-invariant quantities derived from sensed field vector components such as vector modulus or pattern-by-pattern angular difference of vector directions, and inverts classical dipole equation by Newton-Raphson's method to obtain xyz position of the magnetic sensor. Then the orientation of the sensor is determined by simple comparison of absolute and sensed vector directions. A simplest but very practical solution named point-scan system is presented in which four to nine solenoids aligned in a plane and excited one by one cover the box-shaped sensing volume below them. Its experimental result with newly designed hardware is also shown which covers 0.75 by 0.75 by 1m volume with resolution and stability of 1 to 3mm.抄録全体を表示PDF形式でダウンロード (2344K)
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