• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.5
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• pp.1508-1515
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• 1996

The method of utilizing sensitivity linkages for the analysis of mechanical errors are proposed. As sources of the mechanical error, tolerances in the link length and clearances in thejoints are considered. It is demonstrated that the problem of calculating mechanical errors of a 4-bar mechanism can be transformed into a problem of conventeional velocity analysis of a sensitivity linkage. As a result of the present study, it is found and proved that the mechanical error of the output angle in the 4-Bar mechaism is represented as a simple harmonic function with respect to the relative position of the pin on the clearance circle. Also the vector representing the mechanical error of a coupler point makes, in general, an ellipse as the relative angle varies on the clearance circle. With these results we can better identify the characteristic of the mechanical errors in linkages.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2006.06a
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• pp.327-335
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• 2006

Case Based Reasoning (CBR) has come to be considered as an appropriate technique for diagnosis, prognosis and prescription in medicine. However, canventional CBR has a limitation in that it cannot incorporate asymmetric misclassification cast. It assumes that the cast of type1 error and type2 error are the same, so it cannot be modified according ta the error cast of each type. This problem provides major disincentive to apply conventional CBR ta many real world cases that have different casts associated with different types of error. Medical diagnosis is an important example. In this paper we suggest the new knowledge extraction technique called Cast-Sensitive Case Based Reasoning (CSCBR) that can incorporate unequal misclassification cast. The main idea involves a dynamic adaptation of the optimal classification boundary paint and the number of neighbors that minimize the tatol misclassification cast according ta the error casts. Our technique uses a genetic algorithm (GA) for finding these two feature vectors of CSCBR. We apply this new method ta diabetes datasets and compare the results with those of the cast-sensitive methods, C5.0 and CART. The results of this paper shaw that the proposed technique outperforms other methods and overcomes the limitation of conventional CBR.

• The Transactions of the Korea Information Processing Society
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• v.7 no.5
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• pp.1330-1340
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• 2000

Multimedia isn ow applied to various real world areas. In particular, the focus on multimedia system and CSCW(Computer Supported Cooperative Work) has increased. In spite of this current trend, however, the study of fault tolerance for CSCW has not yet fully progressed. We propose EDR_MSCW. It is a system that is suitable for detecting ad recovering software error based on multimedia computer supported cooperative work as DOORAE by using software techniques. DOORAE is a framwork for supporting development on multimedia applications for computer-based collaborative works. When an error occurs, EDR_MCSCW detects an error by using hooking methods in MS-Windows API(Application Program Interface) function. If an error is found, we present a checkpointing and recovery algorithm which has the removal function of the domino-effect for recovering multimedia and CSCW by using stack.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1519-1522
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• 2002

In this paper, we propose a new adaptive dissolve detection method based on the analysis of a dissolve modeling error that is the difference between an ideally modeled dissolve curve without any correlation and an actual variance curve with a correlation. The dissolve modeling error is determined based on a correlation between two scenes and variances for each scene. First, Candidate regions are extracted by using the characteristics of a parabola that is downward convex, then the candidate region will be verified based on a dissolve modeling error. If a dissolve modeling error on a candidate region is less than a threshold that is defined by a dissolve modeling error with a target correlation, the candidate region should be a dissolve region with a correlation less than the target correlation. The threshold is adaptively determined based on the variances between the candidate regions and the target correlation. By considering the correlation between neighbor scenes, the proposed method is able to be a semantic scene-change detector. The proposed algorithm was tested on various types of data and its performance proved to be more accurate and reliable when compared with other commonly used methods

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.3
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• pp.613-621
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• 2016

Since the error control problem is a critical and sensitive issue in the one-way network, we can adopt a forward error correction code method or data retransmission method based on the response of reception result. In this paper, we propose error control method and continuous data transmission protocol in the one-way network which has unidirectional data transmission channel and special channel to receive only the response of reception result. Furthermore we present data encryption and key update mechanism which is based on the pre-shared key distribution scheme and suggest some ASDU(Application Service Data Unit) formats to implement it in the one-way network.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.161-168
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• 2011

Objective: The aim of this study is to review the ISO(the International Organization for Standardization) standards recommendations on a human error tolerant control room design. Background: ISO TC(Technical Committee) 159 published a variety of international standards on design of mental and physical work, design of displays and controls, and workstation layout design. A proper edition of these standards can be a good resource for a human error tolerant control center design guidelines. Method: Recommendations of ISO TC 159 standards were grouped into arrangement of control suite, layout of control room, layout and dimensions of workstations, design of displays and controls, environmental design, alarm, automation, management system design, procedure and training. Results: It was found that some standards on the design of supervisory control and data acquisition(SCADA), alarm, automation, layout, workload management, and environment can be used for human error prevention guidelines in the control center design. Conclusion: ISO TC 159 standards were not sufficient to cover all the ergonomics area of control center design. Application: Designers can have technical aids from these ISO standards to improve ergonomic performance of their control center.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.41-53
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• 2011

Objective: The purpose of this paper is to introduce new research trends of human error and accident modeling and to suggest future promising research directions in those areas. Background: Various methods and techniques have been developed to understand the nature of human errors, to classify them, to analyze their causes, to prevent their negative effects, and to use their concepts during design process. However, it has been reported that they are impractical and ineffective for modern complex systems, and new research approaches are needed to secure the safety of those systems. Method: Six different perspectives to study human error and system safety are explained, and then seven recent research trends are introduced in relation to the six perspectives. The implications of the new research trends and viable research directions based on them are discussed from a cognitive systems engineering point of view. Results: Traditional methods for analyzing human errors and identifying causes of accidents have critical limitations in complex systems, and recent research trends seem to provide some insights and clues for overcoming them. Conclusion: Recent research trends of human error and accident modeling emphasize different concepts and viewpoints, which include systems thinking, sociotechnical perspective, ecological modelling, system resilience, and safety culture. Application: The research topics explained in this paper will help researchers to establish future research programmes.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.132-137
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• 2022

In this paper, we have studied the quadrature error reduction for the single drive 3-axis MEMS Gyroscope. There was a limitation of the previous study which is the z-axis quadrature error was large. To reduce this value, design methodologies were presented. And the methodologies included a different mesh application, z-rate spring structure change, and mass compensation for balancing of the structure. We conducted the modal analysis, drive mode analysis and sense mode analysis using COMSOL Multiphysics. As a result, a drive resonant frequency was 26003 Hz, with the x-sense, y-sense, z-sense being 26749 Hz, 26858 Hz, 26920 Hz, respectively. And the Mechanical sensitivity was computed at 2000 degrees per second(dps) input angular rate while the sensitivity for roll, pitch, and yaw was computed 0.011, 0.012, and 0.011 nm/dps respectively. And z-axis quadrature error was successfully improved, 2.78 nm to 0.95 nm, which the improvement rate was about 66 %.

• Atmosphere
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• v.33 no.1
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• pp.33-47
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• 2023

In this study, for the application of observation errors to the Korean Integrated Model (KIM) to utilize the Constellation Observing System for Meteorology, Ionosphere & Climate-2 (COSMIC-2) new satellites, the observation errors were diagnosed based on the Desroziers method using the cost function in the process of variational data assimilation. We calculated observation errors for all observational species being utilized for KIM and compared with their relative values. The observation error of the calculated the Global Navigation Satellite System Radio Occultation (GNSS RO) was about six times smaller than that of other satellites. In order to balance with other satellites, we conducted two experiments in which the GNSS RO data expanded by about twice the observation error. The performance of the analysis field was significantly improved in the tropics, where the COSMIC-2 data are more available, and in the Southern Hemisphere, where the influence of GNSS RO data is significantly greater. In particular, the prediction performance of the Southern Hemisphere was improved by doubling the observation error in global region, rather than doubling the COSMIC-2 data only in areas with high density, which seems to have been balanced with other observations.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.421-422
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• 2020

Hardware In-the-Loop simulation(HIL)은 실제 하드웨어 시스템을 실시간 모사할 수 있는 시뮬레이션 장비로 연구 및 개발 기간의 단축, 비용저감 등의 장점을 앞세워 다양한 전력전자 분야에 사용되고 있다. 실제 하드웨어를 그대로 모사하는 것이 HIL의 목적이기 때문에 HIL 장비는 검증의 실시간성과 출력된 결과의 정확성이 무엇보다도 중요하다고 할 수 있다. 하지만 코어간의 데이터를 주고받는 과정에서 HIL의 연산 속도 및 정확성을 저해하는 요인들이 발생하게 된다. 본 연구에서는 HIL 장비를 이용해 복잡한 시스템을 구현함에 있어서 연산속도 및 정확성을 저해하는 요인들을 찾아내고 이를 해결하기 위한 방법을 제안한다. 제안된 연산속도 개선 및 정확성 개선 방법의 타당성은 프로세서의 연산 속도 변화량, HIL 및 시험 결과 파형의 비교 분석을 통해 검증되었다.