• 한국통계학회:학술대회논문집
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• 한국통계학회 2005년도 춘계 학술발표회 논문집
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• pp.227-231
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• 2005

민감한 모집단의 모수 추정 방법으로 확률화응답기법과 무응답을 고려한 직접조사 방법의 효율성을 비교 분석하였다.

• 전기학회논문지
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• 제67권11호
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• pp.1555-1561
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• 2018

Tracking and detecting targets by the millimeter wave seeker is affected by movement of platform. Stabilization equipments use an inertial sensor to compensate for disturbance of stabilizing gimbal or platform. In the direct line of sight stabilization system, an inertial sensor is mounted on inner gimbal to compensate the disturbance directly, so the performance is excellent and the implementation method is simple. However gimbal design requires somewhat larger volume. Since an inertial sensor is mounted on gimbal base in the indirect line of sight stabilization system, additional space of gimbal is not required for the gimbal design. However, this method does not directly compensate for the disturbance of the line of sight stabilization axis, which can degrade performance. In order to perform the tracking performance, two methods are analyzed for line of sight stabilization performance based on direct and indirect of a 2-axis gimbaled servo system for millimeter wave seeker in this study. The simulation and experimental results validate the performance comparison of two methods.

• 대한인간공학회지
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• 제20권1호
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• pp.73-86
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• 2001

An analysis of anthropometric data of feet of Korean adults was made in this study. Anthropometric data were measured with the direct measurement method and indirect measurement method. Martin scales and a tapeline were used for direct measurement. Digital images taken with a digital camera as an indirect measurement method were analyzed using AutoCAD program. Total 114 adults aged from 20's to 40's participated in this study. Especially right and left feet were measured. Right and left side were compared and differences according to age were compared too. Feet shape, arch height, and deformation of toe were analyzed. The comparison between right and left foot showed that many subjects had different anthropometric data in their feet. Feet deformation including arch height and claw toe shape showed very serious status. Close and continuous attention to feet deformation is strongly needed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.701-708
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• 1997

A direct boundary element method(DBEM) is developed for thin bodies whose surfaces are rigid or compliant. Th eHelmholtz integral equation and its normal derivative integral equation are adopted simultaneously to calculate the pressure on both sides of the thin body, instead of the jump values across it, to account for the different surface conditions of each side. Unlike the usual assumption, the normal velocity is assumed to be discontinuous across the thin body. In this approach, only the neutral surface of the thin body has to be discontinuous across the thin body. In this approach, only the neural surface of the thin body has to be discretized. The method is validated by comparison with analytic and/or numerical results for acoustic scattering and radiation from several surface conditions of the thin body; the surfaces are rigid when stationary or vibrating, and part of the interior surface is lined with a sound-absorbing material.

• 조명전기설비학회논문지
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• 제22권3호
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• pp.88-95
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• 2008

In the paper, the permanent magnet synchronous generator of 1.5[MW] output power which is driven directly without gear system is designed by conventional magnetic equivalent circuit method and analyzed by finite element method. We analyzed the characteristics of generator like no load, rated load, short circuit condition and demagnetization of permanent magnet in order to verify the design results by magnetic circuit method. The last, the analysis results of two kinds of rotor types are compared with each other. Especially the THD(total harmonic distortion) of output voltage is examined for the comparison.

• 한국진공학회지
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• 제15권6호
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• pp.605-611
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• 2006

정적법(constant volume method)을 이용하여 $1Pa\sim100kPa$ 영역에서 진공게이지의 직접교정 (direct calibration) 장치를 개발하였다. 이 장치는 피 교정 게이지의 이동 없이 in-situ 상태에서 비교교정(comparison calibration)도 가능하다. 이 장치가 개발됨으로서 산업체 교정기관의 생산성을 높이고 개발도상국에 국가 진공표준과 교정기술을 보급할 수 있게 되었다.

• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.433-443
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• 2003

In this study, we provide a comparison of multivariate Q-techniques in the up-to-date versions of SAS, SPSS, Minitab and S-plus well known to those who study statistics. We can analyze data through the direct Input method(command) in SAS and use of menu method in SPSS, Minitab and S-plus. The analysis performance method is chosen by the high frequency of use. Widely we compare with each Q-techniques form according to input data, input option, statistical chart and statistical output.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.31-34
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• 2003

There are several types of switching table for selection voltage vector in direct torque control of induction motor. In general, two-quadrant and four-quadrant operation switching table are used mostly. Two-quadrant operation has an advantage that reduced the torque ripples in comparison with four-quadrant operation, but it has the defect that is not constant average torque. Because the torque increasing slope size by non-zero voltage vector is different from the torque decreasing slope size by zero voltage vector as speed region. The main objective of this study is to maintain constant average torque using two-quadrant operation switching table. In proposed method, the torque increasing slope or decreasing slope are calculated before selected voltage vector is applied. Then, it is applied to zero voltage vector or non-zero voltage vector until the torque increasing slope and decreasing slope are equal. In total magnitude. Therefore it becomes to maintain average torque at whole operation speed. The validity of the proposed method is proven by simulated and experimental results.

• 대한조선학회지
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• 제24권4호
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• pp.19-36
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• 1987

In this research the coupling problem between the elastic structure and the fluid, specially the hydroelastic harmonic vibration problem, is studied. In order to couple the domains, i.e., the structural domain and the fluid domain, the boundary integral method(direct boundary integral formulation) is used in the fluid domain in combination with the finite element method for the structure. The boundary integral method has been widely developed to apply it to the hydroelastic vibration problem. The hybrid boundary integral method using eigenfunctions on the radiation boundaries and the boundary integral method using the series form image-functions to replace the even bottom and free surface boundaries in case of high frequencies have been developed and tested. According to the boundary conditions and the frequency ranges the different boundary integral methods with the different idealizations of the fluid boundaries have been studied. Using the same interpolation functions for the pressure distribution and the displacement the two domains have been coupled and using Hamilton principle the solution of the hydroelastic have been obtained through the direct minimizing process. It has become evident that the finite-boundary element method combining with the eigenfunction or the image-function method give good results in comparison with the experimental ones and the other numerical results by the finite element method.

• 대한치과기공학회지
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• 제39권2호
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• pp.93-99
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• 2017

Purpose: With the development of digital dental technology, we are manufacturing prosthetic crown in various ways. However, the wax-up method that makes existing prosthetic crown is also used steadily. Thus, we will compare the shape of the crown designed with wax-up and the crown designed with CAD. Methods: Sculpt the crown with wax-up on the model to 10 dental technicians. The same model was used to design the crown CAD. Measure the size of the sculpted crown. The shapes were compared in three dimensions. Results: As a result, we could observe a difference in size and shape in crown designed with wax - up crown and crown. Conclusion: These results suggest that there are differences according to the method of carving crown and the method of processing.