• 대한조선학회지
• /
• 제19권2호
• /
• pp.41-60
• /
• 1982

The main idea of this report, which deals with the process analysis in outfitting fields, is to improve working methods and further to secure higher productivity by removing unreasonable work factors in the workshop with the economical point of view. For this purpose, a series of techniques has been applied to some parts of chronically less productive outfitting works, expecting less man hour consumption and better working conditions to go with it. That is to make full use of process chart flow diagram(man & machine chart gang process chart). The text gives brief introductions of the charts respectively and the appendix shows actual practice directly applicable for the guidance of utilizing these charts. As the result of this, some of unreasonable work factors are removed from the total cycle and finally standard working method & time can be come out by reasonable working time and gradually improved working method.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1997년도 추계학술대회 논문집
• /
• pp.304-309
• /
• 1997

Elastic elements, at first, were extensively used in suspensions as vibration isolators at joints. Nowadays they are used to improve stability and handling. The design of these elements has become a very important matter since the loading condition of the mechanism gives a mew suspension geometry without any modification. This paper presents an analysis of forces and moments of joints with elastic elements in the McPherson suspension mechanism to evaluate accurately the elastic deformation using the displacement matrix method in conjunction with the equilibrium equations. First the suspension is modeled as a multi-loop spatial rigid-body guidance mechanism which has elastic elements at the hardpoints of the suspension. Then a method and design euqations are developed to analyze the suspension characteristics by the various tire load. Also the displacement matrices and constraint equations for links are appllied to determine the sensitivity of the suspension mechanism. Finally this approach may conduct a realistic design of suspension mechanisms with elastic elements to improve the performance of the automobile under various driving conditions.

• 대한인간공학회:학술대회논문집
• /
• 대한인간공학회 1996년도 추계학술대회논문집
• /
• pp.125-140
• /
• 1996

Human Factors Engineering(HFE) program should be developed from the early stage of the design process for Nuclear Power Plant. The HFE program is conducted in accordance with the guidance in the Standard Review Plan(SRP) NUREG 0800, Chapter 18. The major purpose of this program is to reduce the incidence of human error during the operating life of the plants. A comprehensive human factors program is prepared by KOPEC to assure that key elements of human factors involvement are not inadvertently overlooked and the early, complete, and continuing inclusion of HFE in the design process. This paper is to introduce engineering steps of the HF activities to verify that the HF involvements on man-machine interface are adequate to support safe and efficient operation of nuclear power plant. If systems are developed without sufficient consideration on the HFE in the design, such systems may cost a high price due to the malfunction of the plant induced by the human errors.

• 한국공작기계학회논문집
• /
• 제17권1호
• /
• pp.150-157
• /
• 2008

Bellows are commonly used in piping systems to absorb expansion and contraction in order to reduce stress. Unlike most piping components, bellows consist of a thin-walled shell of revolution with a corrugated meridian, in order to provide the flexibility needed to absorb mechanical movements. It is a composite shell structure consisting of at least one toroidal shell, an annular plate or conical shell. It is difficult to analyze the behavior of bellows because of its complex geometry. Simplified formulas for variable mechanical behaviors of bellows are provided by a standard called EJMA. An automatic design software for bellows is programming by using VBA(Visual Basic for Application) based on EJMA. Bellows engineers can effectively make a decision for bellows geometries because this software provides graphically design results in its post-processor. Bellows design software is expected to give quite a good guidance to practical design. The characteristics of bellows are also investigated through the automatic design process in bellows design software.

• Journal of Biosystems Engineering
• /
• 제21권2호
• /
• pp.175-181
• /
• 1996

Autonomous speedsprayer operation was conducted using the developed FLC(Fuzzy Logic Controller). Orchard image and signals of ultrasonic sensors were processed in real time. The speedsprayer was modified to be steered by two hydraulic cylinders. The FLC has two inputs, direction of running and distance from obstacles. The operation time of hydraulic cylinders were inferred as output of the FLC. Field test results showed that the speedsprayer could be autonomously operated by the FLC along with the image processing and the ultrasonic sensors. The ultrasonic sensors didn't contribute to the improvement of guidance performance, but the speedsprayer could avoid trees or obstacles in emergent situations with them.

• 산업경영시스템학회지
• /
• 제28권1호
• /
• pp.140-146
• /
• 2005

This study presents the new dispatching rules of job shop scheduling with auxiliary resource constraint to improve the schedule performance measures related to completion time and due dates. The proposed dispatching rules consider the information of total work remaining and machine utilization to decrease mean flowtime and mean tardiness. The results of computer experiments show that those schedule performances are significantly improved by using the new dispatching rules. The results provide guidance for the researchers and practitioners of auxiliary resource constrained job shop scheduling to decrease mean flowtime and mean tardiness.

• 산업기술연구
• /
• 제31권A호
• /
• pp.3-9
• /
• 2011

Simulation plays an important role for system analysis. In this study, a manufacturing system has been analyzed through computer simulation. We first briefly explain the considered system with prevailing problems. We then build a simulation model using ARENA simulation language. Based on two selected performance measures, material transporter load and hourly throughput, explicit system analyses have been performed. We addressed four parameters - variation of the processing time, number of raw material transporters, quality failure rate, and machine failures - as the input parameters affecting the output measures selected. We adopted Taguchi's orthogonal array in statistical experimental design and drew meaningful results from the analysis. The results given in the study may provide a good guidance for practical applications.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2021년도 추계학술대회
• /
• pp.21-22
• /
• 2021

Early academic warning is considered as an inherent problem in education data mining. Early and timely concern and guidance can save a student's university career. It is widely assumed as a multi-class classification system in view of machine learning. Therefore, An accurate and precise methodical solution is a complicated task to accomplish. For this issue, we present a hybrid model employing rough set theory with a back-propagation neural network to ameliorate the predictive capability of the system with an illustrative example. The experimental results show that it is an effective early academic warning model with an escalating improvement in predictive accuracy.

• 정보보호학회논문지
• /
• 제30권3호
• /
• pp.443-454
• /
• 2020

자바스크립트 엔진은 주로 웹 브라우저에 적재되어 웹 페이지를 표시하는 여러 기능 중 자바스크립트 코드를 입력으로 받아 처리하는 모듈이다. 자바스크립트 엔진 내 취약점은 종단 사용자의 시스템 보안을 위협할 수 있어 많은 퍼징 테스트 연구가 수행되었다. 그중 일부 연구는 자바스크립트 엔진 내 테스트 커버리지를 유도하는 방식으로 퍼징 효율을 높였으나, 최적화되어 동적으로 생성된 기계어 코드에 대한 커버리지 유도 퍼징은 시도되지 않았다. 최적화된 자바스크립트 코드는 예외적인 흐름 발생 시 코드를 해제하는 런타임 가드의 기능으로 인해 퍼징을 통한 충분한 반복 테스트가 어렵다. 본 논문은 이러한 문제점을 해결하기 위해 최적화 해제를 회피하여 최적화된 기계어 코드에 대해 퍼징 테스트를 수행하는 방법을 제안한다. 또한, 동적 바이너리 계측 방식으로 수행된 런타임 가드의 커버리지를 계측하고 커버리지 증가를 유도하는 방식을 제안한다. 실험을 통해, 본 연구가 제안하는 방식이 런타임 가드 커버리지, 시간당 테스트 횟수의 두가지 척도에서 기존의 방식보다 뛰어남을 보인다.

• 한국재난정보학회 논문집
• /
• 제13권4호
• /
• pp.422-441
• /
• 2017

사물 인터넷을 기반으로 지하철역사의 재난 전조를 조기에 발견하고 승객들에게 피난을 유도하는 지하철 재난전조 감지 시스템 개발에 있어서 재난 발생시 상황대피 유도방법과 정확한 재난 위치 알림 및 대피경로 안내는 재난 상황에 빠른 대피와 인명피해를 최소화 할수 있는 매우 적극적인 대안이 될 수 있다. 좁은 출구밖에 없는 지하공간 구조상 소방 시설 및 장비들의 완벽한 작동을 담보하기란 쉽지 않다. 따라서 본 연구에서는 대피를 가장 효율적으로 유도할 수 있는 재난대응 EL Display 통합 보드를 개발하였으며 이를 현장 실험을 통해 실제 활용성에 대한 검토를 실험하였다. 특히, EL패널을 재난 대피유도용으로 활용한 사례가 없어 현장적용테스트를 거쳐 그 활용 가능성을 검증하였다.