• Title/Summary/Keyword: difference systems

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An Advanced Prediction Technology of Assembly Tolerance for Vehicle Door (차량도어 조립공차 예측기술 개발)

  • Jeoung, Nam-Yeoung;Cho, Jin-Hyung;Oh, Hyun-Seung;Lee, Sae Jae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.4
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    • pp.91-100
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    • 2018
  • The setting of values on door hinge mounting compensation for door assembly tolerance is a constant quality issue in vehicle production. Generally, heuristic methods are used in satisfying appropriate door gap and level difference, flushness to improve quality. However, these methods are influenced by the engineer's skills and working environment and result an increasement of development costs. In order to solve these problems, the system which suggests hinge mounting compensation value using CAE (Computer Aided Engineering) analysis is proposed in this study. A structural analysis model was constructed to predict the door gap and level difference, flushness through CAE based on CAD (Computer Aided Design) data. The deformations of 6-degrees of freedom which can occur in real vehicle doors was considered using a stiffness model which utilize an analysis model. The analysis model was verified using 3D scanning of real vehicle door hinge deformation. Then, system model which applying the structural analysis model suggested the final adjustment amount of the hinge mounting to obtain the target door gap and the level difference by inputting the measured value. The proposed system was validated using the simulation and showed a reliability in vehicle hinge mounting compensation process. This study suggests the possibility of using the CAE analysis for setting values of hinge mounting compensation in actual vehicle production.

Application of robust fault detection method for uncertain systms to diesel engine system (불확실성을 고려한 디젤엔진의 견실한 이상검출)

  • 유경상;김대우;권오규
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1419-1422
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    • 1997
  • This paper deals with the Appliation of robust fault detection problem in uncertain linear systems, having both model mismatch and noise. A robust fault detection method presented by Kwon et al.(1994) for SISO uncertain systems. Here we experimented this method to the diesel engine systems described by difference ARMA models. The model mismatch includes here linearization error as well as undermodeling. Comparisons are made with alternative fault detection method which do not account noise. The new method is shown to have good performance.

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The Relation of the Videotex Systems and Library Services (비디오텍스 시스템과 도서관 봉사간의 관계)

  • Sung Kee-Joo
    • Journal of the Korean Society for Library and Information Science
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    • v.24
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    • pp.171-204
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    • 1993
  • The purpose of this study is to verify the hypothesis that the contents and range of library services are changed as the use of videotex systems increases. 1000 members of Chollian II were chosen as subjects for this study and the questionnaire was posted to them. The returned responses to questionnaire were analyzed with the statistical software packages 'SAS PC' and 'STATGRAPHICS'. The findings and conclusions of this study are summarised as follows: 1. Users of Chollian II make more use of videotex systems in seeking daily information than in seeking scholarly and professional information. It seems desirable to co-ordinate the services of videotex systems and libraries by redefining the traditional boundary of the two systems. Users will then conveniently get daily information through videotex servics, scholarly and professional information through the reference service of libraries. 2. Sex does not make any significant difference in the use of videotex systems. Most frequent use of videotex systems is made by those at the age of thirties. Businessmen and enterprisers make the most frequent use of videotex systems. Those of higher education are the best users. 3. As the use of videotex systems increases, use of newspapers and periodicals decreases while its increase rarely has influence on the use of library materials. 4. There is limited correlation between the use of videotex systems and that of library services. The increase of the use of videotex systems does not significantly increase or decrease the use of libraries. It changes, however, the pattern and methods of information services provided by libraries. 5. Users of special libraries make the most frequent use of videotex systems and there is not much difference in the use by users of other kinds of libraries.

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CLOSE/WIDE DEGENERACY IN CENTRAL PERTURBATIONS OF PLANETARY LENSING

  • Kim, Do-Eon;Han, Cheong-Ho;Park, Byeong-Gon
    • Journal of The Korean Astronomical Society
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    • v.42 no.3
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    • pp.39-45
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    • 2009
  • We investigate the degeneracy in the pattern of central microlensing perturbations of a pair of planetary systems where the planets are located from the primary with projected separations in units of the Einstein radius s and $s^{-1}$, respectively. From this, we confirm the fact that although alike, the patterns of central perturbations induced by a close (s < 1) planet and a wide (s > 1) planet are not identical and the degree of difference depends on the planet/primary mass ratio and the planet-primary separation. We find that the difference can be greater than 5% for planetary systems with lensing parameters located in the parameter space of (1/1.8 < |s| < 1.8, q > $5{\times}10^{-3}$), (1/1.3 < |s| < 1.3, q > $1{\times}10^{-3}$), and (1/1.2 < |s| < 1.2, q > $5{\times}10^{-4}$), where q represents the planet/primary mass ratio. Although this range occupies a small fraction of the entire parameter space of planetary systems, we predict that the chance of resolving the close/wide degeneracy would not be meager considering that the planet detection efficiency is higher for planets with resonant separations (s $\sim$ 1) and heavier masses. We also find that the differences between the perturbation patterns are basically caused by the effect of the planetary caustic. This explains the tendency of the perturbation difference where (1) the difference increases as the planet/primary mass ratio increases and the separation approaches the Einstein radius, (2) the region of major difference is confined within the region around the line connecting the central and the planetary caustics, and (3) a wide (close) planetary system has a more extended central perturbation region toward the (opposite) direction of the planet.

Design of a Robot-in-the-Loop Simulation Based on OPRoS (OPRoS 기반 로봇시스템의 Robot-in-the-Loop Simulation 구조)

  • Kim, Seong-Hoon;Park, Hong Seong
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.3
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    • pp.248-255
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    • 2013
  • This paper proposes the architecture of the RILS (Robot-in-the-Loop-Simulation) consisting of the robot, the virtual robot, and the avatar robot which is the type of virtual robots operating according to the robot status and behavior. And the synchronization algorithm for mobilization part of the avatar robot is suggested, which reduces the difference between behaviors of the robot and those of the avatar robot. This difference occurs due to the environmental and mechanical mismatches between the robot and avatar robot. In order to reduce this difference in robots behaviors, the synchronization algorithm controls the avatar robot based on the data observed from the robot's behavior. The proposed architecture and the synchronization algorithm are validated from some simulation results.

SOME RESULTS ON COMPLEX DIFFERENTIAL-DIFFERENCE ANALOGUE OF BRÜCK CONJECTURE

  • Chen, Min Feng;Gao, Zong Sheng
    • Communications of the Korean Mathematical Society
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    • v.32 no.2
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    • pp.361-373
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    • 2017
  • In this paper, we utilize the Nevanlinna theory and uniqueness theory of meromorphic function to investigate the differential-difference analogue of $Br{\ddot{u}}ck$ conjecture. In other words, we consider ${\Delta}_{\eta}f(z)=f(z+{\eta})-f(z)$ and f'(z) share one value or one small function, and then obtain the precise expression of transcendental entire function f(z) under certain conditions, where ${\eta}{\in}{\mathbb{C}}{\backslash}\{0\}$ is a constant such that $f(z+{\eta})-f(z){\not\equiv}0$.

Thermal analysis of a thermal capacitor for the current lead cooling in conduction-cooled superconducting systems (전도냉각형 초전도시스템의 전류도입선 냉각을 위한 열커패시터의 열적해석)

  • 권기범;양형석;정은수;장호명
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.31-34
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    • 2002
  • In this study, thermal analysis of a thermal capacitor, which is used to cool the current lead in conduction-cooled superconducting systems, was done. The temperature difference across a thermal capacitor was calculated by using heat conduction equation. Effect of heat load, total thickness, height and length of a thermal capacitor on the temperature difference were show. Using the results in this work, total thickness and heat height of a thermal capacitor can be determined for given heat load and given temperature difference. This work can be used practically in design for every superconduction system using a current lead.

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Sound Source Tracking Control of a Mobile Robot Using a Microphone Array (마이크로폰 어레이를 이용한 이동 로봇의 음원 추적 제어)

  • Han, Jong-Ho;Han, Sun-Sin;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.4
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    • pp.343-352
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    • 2012
  • To follow a sound source by a mobile robot, the relative position and orientation of the sound source from the mobile robot have been estimated using a microphone array. In this research, the difference among the traveling times of the sound source to each of three microphones has been used to calculate the distance and orientation of the sound source from the mobile robot which carries the microphone array. The cross-correlation between two signals has been applied for detecting the time difference between two signals, which provides reliable and precise value of the time difference comparing to the conventional methods. To generate the tracking direction to the sound source, fuzzy rules are applied and the results are used to control the mobile robot in a real-time. The efficiency of the proposed algorithm has been demonstrated through the real experiments comparing to the conventional approaches.

The AGPS/INS Integrated Navigation System Design Using Triple Difference Technique (삼중 차분 기법을 이용한 AGPS/INS 통합 항법 시스템 설계)

  • 오상헌;박찬식;이상정;황동환
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.9
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    • pp.736-744
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    • 2003
  • The GPS attitude output or carrier phase observables can be effectively utilized to compensate the attitude error of the strapdown inertial navigation system. However, when the integer ambiguity is not correctly resolved and/or a cycle slip occurs, an erroneous GPS output can be obtained. If the erroneous GPS information is directly applied to the AGPS/INS integration system, the performance of the system can be rapidly degraded. This paper proposes an AGPS/INS integration system using the triple difference carrier phase observables. The proposed integration system contains a cycle slip detection algorithm, in which inertial information is combined. Computer simulations and van test were performed to verify the proposed integration system. The results show that the proposed system gives an accurate and reliable navigation solution even when the integer ambiguity is not correct and the cycle slip occurs.

Intermediate Image Generation of Stereo Image Using Depth Information and Block-based Matching Method (깊이정보와 블록기반매칭을 이용한 스테레오 영상의 중간영상 생성)

  • 양광원;허경무;김장기
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.10
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    • pp.874-880
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    • 2002
  • A number of techniques have been proposed for 3D display using view-difference of two eyes. These methods do not express enough reality like real world. The display images have to change according to the position of a viewer to improve reality. In this paper, we present an approach for generating intermediate image between two different view images by applying new image interpolation algorithm The interpolation algorithm is designed to cope with complex shapes. The proposed image interpolation algorithm generates rotated image about vertical axes by any angle from base images. Each base image that was obtained from CCD camera has an view-angle difference of $3^{\circ}C$, $5.5^{\circ}C$, $^{\circ}C$, $22^{\circ}C$, and $45^{\circ}C$. The proposed into mediate image generation method uses the geometric analysis of image and depth information through the block-based matching method.