• Structural Engineering and Mechanics
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• 제28권2호
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• pp.167-188
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• 2008

This study is concerned with the establishment of the characteristic equation of a combined system consisting of a cantilever beam with a tip mass and an in-span visco-elastic helical spring-mass, considering the mass of the helical spring. After obtaining the "exact" characteristic equation of the combined system, by making use of a boundary value problem formulation, the characteristic equation is established via a transfer matrix method, as well. Further, the characteristic equation of a reduced system is obtained as a special case. Then, the characteristic equations are numerically solved for various combinations of the physical parameters. Further, comparison of the results with the massless spring case and the case in which the spring mass is partially considered, reveals the fact that neglecting or considering the mass of the spring partially can cause considerable errors for some combinations of the physical parameters of the system.

• 지적과 국토정보
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• 제53권2호
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• pp.39-52
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• 2023

지적도는 중요한 공문서로 재산권에 영향을 미치며, 100년 이상 사용으로 인한 문제가 발생했다. 오래된 지적도면의 훼손, 마모, 재작성 과정의 오류 누적으로 정확성이 떨어졌고, 전산화 과정에서 이 오류들이 남아 도면 관리에 어려움을 겪고 있다. 전국 지적도‧임야도 정비사업이 진행 중이나, 수정에는 기술적, 법적 난제가 있다. 본 연구는 도면 유지보수의 기술적 측면을 다루며, 도곽접합을 선행하여 오류를 줄이고 정비율을 향상시키는 방법을 제안한다. 연구 결과 도곽접합을 선행할 경우, 평균 거리차이가 22.56cm에서 8.12cm로 감소하고 정비율이 10% 이상 상승함을 확인했다.

• Nuclear Engineering and Technology
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• 제50권4호
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• pp.532-541
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• 2018

Decision support systems are a key focus of research on developing control rooms to aid operators in making reliable decisions and reducing incidents caused by human errors. For this purpose, models of complex systems can be developed to diagnose causes or consequences for specific alarms. Models applied in safety systems of complex and safety-critical systems require rigorous and reliable model building and testing. Multilevel flow modeling is a qualitative and discrete method for diagnosing faults and has previously only been validated by subjective and qualitative means. To ensure reliability during operation, this work aims to synthesize a procedure to measure model performance according to diagnostic requirements. A simple procedure is proposed for validating and evaluating the concept of multilevel flow modeling. For this purpose, expert statements, dynamic process simulations, and pilot plant experiments are used for validation of simple multilevel flow modeling models of a hydrocyclone unit for oil removal from produced water.

• 한국학교수학회논문집
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• 제14권3호
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• pp.277-293
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• 2011

본 논문은 수학문제해결 과정에서 고등학교 1학년 학생들이 공통적으로 범하는 실수 즉 오류를 분석을 통하여 수학의 교수학습방법의 보완을 위한 범례를 제시하고자 한다. 교사들 에게 제공되는 학생들의 수학적 지식에 대한 이해 정도 및 쉽게 빠지는 오류, 수학문제에 접근하는 방법 및 잘못된 해결 전략 등의 정보는 대체로 학생들의 오류를 분석함으로써 얻어 질 수 있다. 실제로 많은 학생들이 고교수학을 어렵게 느끼는데 그 중 특히 '함수'문제에서 막연한 어려움과 부담감을 느끼며 함수와 관련된 문제풀이에서 많은 실패를 겪고 있다. 구체 적으로 본 연구에서는 고등학교 1학년 학생들의 함수단원 문제해결 과정에서 보이는 오류를 분석하여 함수단원 수학문제해결능력을 키우고자 충남의 ${\bigcirc}{\bigcirc}$고등학교 1학년 학생 90명을 대상으로 함수단원 8문제로 구성된 검사지를 풀게 하고 그것을 토대로 오류를 분석하였다. 그 결과 학생들의 오류에서 몇 가지 공통적인 패턴이 있음을 발견하고 이것을 7가지 오류 분류 패턴을 설정하고 이를 분석하여 이를 보완할 수 있는 방법을 탐구하였다. 본 연구에서 나타난 결과를 토대로 학교현장에 투입하여 수학교육의 개선에 도움이 되길 기대한다.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제2권
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• pp.181-191
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• 1997

The purpose of this study is to provide the primary sources to improve the problem solving performance by analyzing the errors and the strategies selection of the high school students when solving given algebraic problems. To attain the purpose of this study, the questions for investigation in this study are : 1. What are the differences / similarities in the patterns of errors committed by successful and unsuccessful problem-solvers when solving particular algebraic problems ? 2. What are the error types chosen by unsuccessful problem-solvers when solving particular algebraic problems? 3. Do students utilize checking, either locally or globally, when solving particular algebraic problems? Twenty students were drawn out of 10th grade students in J girls' high school in Yengi -gun, Chung-Nam, for this study. The problem-solving test was used as a test instrument. From the data, the verbal protocols and the written protocols were analyzed by the patterns. The conclusions drawn from the results obtained in the present study are as follows: First, in solving particular algebraic problems, when the problems were solved with one strategy, most students didn't give any consideration to other strategies. So mathematics teachers should teach them to use the various strategies, and should develop the problems to be used the various strategies. Second, in solving particular algebraic problems, errors on notions or transformations of equations were found. Thus, the basic knowledges related to equation should be taught. In addition, most unsuccessful students seleted the strategies inadequately to solve the problems because of misunderstanding the problems. So, to improve the problem solving performance the processes of 'understanding problem' should be emphasized to students. Third, although the unsuccesful students used the 'checking' processes when solving the problems, most of them did not find the errors because of misconceptions related to the problems, carelessness, and unskillfulness of checking. Thus, students must be taught more carefully and encouraged to use the checking.

• Nuclear Engineering and Technology
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• 제45권2호
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• pp.125-140
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• 2013

This paper aims to give an overview of the methods to inherently prevent human errors and to effectively mitigate the consequences of such errors by securing defense-in-depth during plant management through the advanced man-machine interface system (MMIS). It is needless to stress the significance of human error reduction during an accident in nuclear power plants (NPPs). Unexpected shutdowns caused by human errors not only threaten nuclear safety but also make public acceptance of nuclear power extremely lower. We have to recognize there must be the possibility of human errors occurring since humans are not essentially perfect particularly under stressful conditions. However, we have the opportunity to improve such a situation through advanced information and communication technologies on the basis of lessons learned from our experiences. As important lessons, authors explained key issues associated with automation, man-machine interface, operator support systems, and procedures. Upon this investigation, we outlined the concept and technical factors to develop advanced automation, operation and maintenance support systems, and computer-based procedures using wired/wireless technology. It should be noted that the ultimate responsibility of nuclear safety obviously belongs to humans not to machines. Therefore, safety culture including education and training, which is a kind of organizational factor, should be emphasized as well. In regard to safety culture for human error reduction, several issues that we are facing these days were described. We expect the ideas of the advanced MMIS proposed in this paper to lead in the future direction of related researches and finally supplement the safety of NPPs.

• 한국학교수학회논문집
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• 제5권1호
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• pp.69-86
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• 2002

This study accordingly brought the analysis of the error into focus to instruct the liner inequality efficiently. Students, in result, committed errors: misused data(14.6%), misinterpreted problem(15.0%), logically invalid inference(2.7%), misunderstood theorem or definition(22.1%), unmatched solution(22.4%), technical error(17.5%), omission of solving process(5.7%). Through the analysis of preceding errors, I try to emphasize the following in instructing students: First, you must emphasize studying of concept of the liner inequality and instruct students in the use of that Second, you must minimize the error by searching for the error that students are apt to commit and showing the anti-example when you instruct them in the liner inequality. Third, after evaluation, you must tell the result to students, and show many forms of the liner inequality with various means lest they should commit the same error. Therefore, if an instructor gives lessons to the students studying the instructive methods in order not to make errors about the contents mentioned above, it will help students understand much faster and arouse their curiosities and interests in lessons, and so they will take lessons willingly.

• 한국생산제조학회지
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• 제6권1호
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• pp.100-108
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• 1997

Electrostatic precipitator is the equipment that separates dust particles from the gas in which they are suspended. Specially, for the construction of industrial electrostatic precipitator, the corporations would send the layout design to a customer to accept an order. Therefore, it is made a detail drawing after accept ance. Since the layout design of electrostatic precipitator is very complex, it takes time and design errors are included. Thus, for competitiveness in these industries, the development of software for the layout design of electrostatic precipitator is important. In this study, the developed software deals with technical concept and layout design of industrial electrostatic precipitator. By using the software, design time was very short, design errors reduced largely, and the standardization of design could be carried out.

• 한국공작기계학회논문집
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• 제14권3호
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• pp.16-22
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• 2005

It is difficult to separate those of NC controller from the error of machine tools because the conventional testing methods to inspect the performance are including the errors of moving system, therefore it has been used as the methods that compare the other controllers. Also, it is hard to predict the machine itself errors with the methods assembling the NC controller and moving system on machine because of the variable load conditions. In this study, the performance inspecting system was developed by analyse the $axis\_rotating$ properties of servo system finally outputting from NC controller. The axis torque was controlled by motor dynamometer and the rotating position accuracy was measured by this developed system.

• Journal of Astronomy and Space Sciences
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• 제27권2호
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• pp.135-144
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• 2010

In this paper, we present the result of preliminary design of tracking mount for ARGO-M which is a movable satellite laser ranging (SLR) system developed by Korea Astronomy and Space Science Institute (KASI). The tracking mount consists of a couple of core parts such as driving motors, encoders and bearings, and the requirements of each parts are determined on the basis of the technical consideration. 2D and 3D models for tracking mount were preliminarily designed using the selected core parts. In order to evaluate the validity of the preliminarily design, the simulator to test the elevation axis was designed and manufactured. The test to check the tracking performance and system accuracy of the simulator was performed, and it was confirmed that the preliminary design meets the operating specifications. Additionally, it was found that the repetitive errors and hysteresis errors need to be improved by the additional control algorithm.