• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.451-456
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• 1991

A robust position control scheme for DC Motor is proposed based on Fuzzy Acceleration Control. Proposed control system has the similar structure that Y. Hori proposed. But the PI type acceleration controller of it is replaced by Fuzzy Logic Controller(FLC) which is known to be robust to the operating point and parameter variations. By the simulation study for a real DC Motor, we have slowed the superiority to the continuous PI acceleration controller in the view point of robustness to the operating point and parameter variations.

• Journal of the Korean Institute of Navigation
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• v.12 no.3
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• pp.23-37
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• 1988

This paper deals with the method of determining the drag of hull surface which has any quality of roughness. The method consists mainly of the theoretical point of view, then the theory enables the drag coefficient to be calculated at full scale. The hydrodynamical roughness function of hull surface ${\triangle}U_+$, affected by the hull roughness are considered as to two cases, smooth surface and rough surface case separately. The inadequacy of a single parameter to define hull roughness is discussed and thus an as additional texture parameter is proposed.

• Journal of Astronomy and Space Sciences
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• v.21 no.3
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• pp.209-220
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• 2004

Some methods have been presented to get optimal formation trajectories in the step of configuration or reconfiguration, which subject to constraints of collision avoidance and final configuration. In this study, a method for optimal formation trajectory-planning is introduced in view of fuel/time minimization using parameter optimization technique which has not been applied to optimal trajectory-planning for satellite formation flying. New constraints of nonlinear equality are derived for final configuration and constraints of nonlinear inequality are used for collision avoidance. The final configuration constraints are that three or more satellites should be placed in an equilateral polygon of the circular horizontal plane orbit. Several examples are given to get optimal trajectories based on the parameter optimization problem which subjects to constraints of collision avoidance and final configuration. They show that the introduced method for trajectory-planning is well suited to trajectory design problems of formation flying missions.

• Journal of Veterinary Clinics
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• v.17 no.1
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• pp.178-186
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• 2000

Echocardiography was performed on 29 normal Korea Jin-do dogs(21 adults and 8 prematures) and the images were taken from chordae tendineae level short-axis view, left ventricular outflow tract long-axis view and 4-chamber long-axis view, respectively. The following cardiac parameters, in systole and diastole, were measured on the echoocardographic images: aortic dimension(AO), left atrial dimension(LA), left ventricular internal dimention at end-diastole (LVIDd), left ventricular internal dimention at end-systole(LVIDs), interventricular septal wall thickness at end-diastole(IVSd), interventricular septal wall thickness at end-systole(IVSs), left ventricular wall at end-diastole(LVWd), left ventricular wall at end-systole(LVWs). The cardiac parameters were not significantly different between sex and among imaging planes. The size of cardiac parameters increaed as regression lines according to body weights. These results suggest that the chordae tendineae level short-axis view, left ventricular outflow tract long-axis view and 4-chamber long-axis view can be utilized for the left cardiac examination, and these cardiac parameters can be used to basic dat for diagnosing the cardiac diseases in Korea Jin-do dog.

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.1-10
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• 1998

The idea of level-of-detail based on multiresolution model is gaining popularity as a natural means of handling the complexity regarding the realtime rendering of virtual environments. To generate an effective multiresolution model, we should capture the prominent visual features in the process of simplifying original complex model. In this paper, we incorporate view dependent features such as silhouette features and backface features, to the generation process of multiresolution model. To capture the view directional parameter, we propose multiresolution view sphere. View sphere maps the directional relationship between object surface and the view. Using the view sphere, coherence in the directional space is mapped into spatial coherence in the view sphere. View sphere is generated in multiresolution fashion to simplify the object. To access multiresolution view sphere efficiently, we devise quad tree for the view sphere. We also devise a mechanism for realtime simplification process using proposed view sphere. Using proposed mechanism, regenerating simplified model in realtime is effectively done in the order of number of rendered vertices.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.150-157
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• 2009

In this paper, we propose a person tracking based multi-channel audio panning system for multi-view broadcasting services. Multi-view broadcasting is to render the video sequences that are captured from a set of cameras based on different viewpoints, and multi-channel audio panning techniques are necessary for audio rendering in these services. In order to apply such a realistic audio technique to this multi-view broadcasting service, person tracking techniques which are to estimate the position of users are also necessary. For these reasons, proposed methods are composed of two parts. The first part is a person tracking method by using ultrasonic satellites and receiver. We could obtain user's coordinates of high resolution and short duration about 10 mm and 150 ms. The second part is MPEG Surround parameter-based multi-channel audio panning method. It is a method to obtain panned multi-channel audio by controlling the MPEG Surround spatial parameters. A MUSHRA test is conducted to objectively evaluate the perceptual quality and measure localization performance using a dummy head. From the experiments, it is shown that the proposed method provides better perceptual quality and localization performance than the conventional parameter-based audio panning method. In addition, we implement the prototype of person tracking based multi-view broadcasting system by integrating proposed methods with multi-view display system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1131-1134
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• 2003

Unknown parameters of a nonlinear system were estimated using a signal compression method. The estimated parameters were natural frequency and tile damping coefficient. This study applied a algorithm using tile comparison of the cross-correlation coefficient between the impulse response from a model and it from the signal compression method. The impulse through linear element included in a nonlinear system could be obtained by the signal compression method. The unknown parameters of the linear element could be estimated by comparing the Bode plots of system's impulse response with them of model's response. In this study, a LSCM(LabVIEW-Signal-Compression-Method) was developed to identify a nonlinear system. The LSCM consisted of National Instrument's (NI) Data Acquisition (DAQ) Board (Model PCI-1200), a monitoring program using LabVIEW software package, DAQ Signal Accessory Board, and 2nd-order electric circuits. The designed electric circuits consisted of resistors, inductors and capacitors. To evaluate the performance of the LSCM, the response from model with known parameters is compared with the response from the real system using the monitoring program. The results from simulation of experiment showed that the developed LSCM provided a reliable estimation performance.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1303-1308
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• 2008

This paper presents effects of impeller geometrical parameters on the performance of a centrifugal pump impeller. The effects of meridional parameters and vane plane development parameters on the performance of the impeller were numerically studied using a commercial CFD code and DOE(design of experiments) software. Geometrical parameters in a method of meridional view and vane plane development were selected and defined to generate the 3D impeller shape. The response variables are defined in a total head and efficiency curve with flow rate. The influences of selected design variables on the various objective functions were examined as a result of the calculation using 2k factorial.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.2
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• pp.149-163
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• 1994

A novel method of dimensional measurement using machine vision, which is called Landmark Tracking System, has been developed. Its advantages come form tracking only the bright, standard shaped "landmarks" which are made from retroreflective sheets. In the design of the LTS, it is essential to know the relationship between optical parameters and their influence on system performance. Such optical parameters include the brightness of landmark image, the illumination system design, and the choice of imaging optics. And the performance of retroreflective material also plays important role in the LTS performances. Influences of such optical parameters on LTS's dimensional measurement characteristics are investigated, with respect to the retroreflective material, the imaging optics, and the illumination system. Measuremtn errors due to parameter variations are also analyzed. Experiments are performed with a LTS prototype. Retroreflective characteristics are verified, and the LTS's measurement performances are measured in the form of repeatability and accuracy. Experimental results shgow that the LTS has repeatability better than 1/30,000 of a field of view(30 degrees), and accuracy better tha 1/3,000 of a field fo view.d fo view.

• Journal of the Chungcheong Mathematical Society
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• v.8 no.1
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• pp.137-145
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• 1995

In the white noise analysis the one-parameter groups play the powerful role. In this report, we will see a subgroup of infinite dimensional unitary group $U_{\infty}$ including guage transform and structure of this subgroup under the view point of Lie algebra.