• 항공우주기술
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• 제3권2호
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• pp.208-216
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• 2004

항공기 전기체 구조시험에 사용되는 기존의 과하중 방지모듈의 성능을 개량하여 고성능의 과하중방지 모듈을 개발하였다. 항공기 전기체 구조시험 수행시에는 예기치 않은 오류(자연재해로 인한 정전사고, 시험체의 파손, 설계강도 미달로 인한 시험정지 등)로 인해 시험하중보다 큰 하중이 시험체에 가해질 수 있다. 이 때 발생한 과하중을 해소하여 시험체를 파손으로부터 보호하는 과하중 방지기능이 필요하다. 본 논문에서는 상용의 기존 과하중 방지모듈에 대해 구성요소별로 기능을 살펴보고, 기존 제품을 이용하여 구조시험을 수행하는 도중 나타난 문제점을 분석하였다. 또한, 기존 과하중 방지모듈이 갖고 있는 문제점을 개선한 고성능 과하중 방지모듈의 개발에 대해 기술하였다.

• 한국전자통신학회논문지
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• 제14권2호
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• pp.339-344
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• 2019

본 논문에서는 주택 전기 과부하로 인한 전기화재 피해를 최소화할 수 있는 스마트 주택 자동화를 위한 DSP 기반의 디지털 주택 과부하 경보기를 실험 제작하였다. 그리고 주택 과부하 경보 기술의 유효성을 검증하기 위해서 인공적으로 과부하를 발생시킬 수 있는 하나의 전기 과부하 경보 성능 평가 시스템을 설계, 개발, 구축하고, 과부하 시험을 통해 개발된 주택 과부하 경보기의 유효성을 검증하였다. 특히, EMTP-RV를 이용하여 과부하 시험 모델을 개발하고 과부하 시험을 모의, 계측결과와 비교함으로서 과부하 성능 검증결과의 신뢰성을 확인하였다.

• 한국해양공학회지
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• 제6권1호
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• pp.96-104
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• 1992

Aircraft structures and engineering structures are always subject to variable amplitude loads. Variable amplitude loads include some kind of loading history; for example, constant amplitude load, single peak overload and block overload etc. Crack growth under variable amplitude loading exhibits retardation effect. In this study, the 4 point bending fatigue test was performed by hydrolic servo fatigue testing machine on 7075-T6 Al-alloy. The retardation effect of overload ratio and numbers of overload cycle was quantitatively studied. 1) Change of retardation effect against increment of overload ratio is more evident when the multiple overload is applied than single overload is done. 2) The number of overload cycle is very important factor about the crack growth retardation effect when the overload ratio is more than 1.75; that is not when the overload ratio is less than 1.75. 3) Overload affected zone size increased gradually by increment of crack growth retardation effect. 4) Crack driving force is more greatly reduced when the crack tip branched off two direction than it sloped to one direction.

• 대한전기학회논문지:전력기술부문A
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• 제53권9호
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• pp.513-520
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• 2004

In the paper, we summarize the result of the experimental research for the overload criteria of domestic distribution transformers considering the electric consumption patterns of customers. For the basic characteristic data of distribution transformer overload, the actual experiments are accomplished. The field data of loads are surveyed from sample transformers for analyzing the consumption pattern of customer load. The load data acquisition devices are equipped, and the algorithm of load pattern classification is applied. In addition to this efforts, various load pattern data. in past are gathered. Then the representative load pattern of each customer type in domestic is extracted. The final results of overload criterions are presented as tabular form through the results of experiments and survey are combined. The field test of the experiment results is peformed using the special manufactured transformers, which can measure both the load and top-oil temperature of transformer. Through this, we verify that the results of field test are similar to the laboratory one and the Proposed overload criteria can be effectively applied to the real system.

• 대한안전경영과학회지
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• 제24권1호
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• pp.81-89
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• 2022

Since the competitive environment, work overload among employees has been increasing. The purpose of this paper is to investigate the impact of work overload on safety behavior and its intermediating mechanisms. In specific, this paper delves into the mediating effect of job stress, as well as the moderating effect of job crafting in the association between work overload and job stress. To empirically test the hypotheses, this study utilized survey data from 168 Korean employees by conducting structural equation modeling(SEM) analysis. The results demonstrated that work overload has a positive (+) influence on job stress, which has a negative (-) influence on safety behavior. Moreover, job stress mediated the association between work overload and safety behavior. Furthermore, job crafting moderated the work overload-safety behavior link.

• 한국정밀공학회지
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• 제21권4호
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• pp.161-169
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• 2004

In this study, we investigated fatigue crack growth behavior of laser welded sheet metal due to a single overload. Fatigue specimens were made using butt joint of cold rolled sheet metal that was welded by $CO_2$ laser. The fatigue crack propagation tests were performed in such a way that fatigue loading was parallel to the weld line while crack propagation was perpendicular to the weld line. Single overload was applied when fatigue crack tip was arrived near the weld line. The distances between the crack tip and the weld line at which a single overload was applied were 6, 4 and 2mm. The effect of specimen thickness and overload ratio on the fatigue behavior was determined. The plastic zone size of crack tip due to the single overload was determined from the finite element analysis. For investigating fatigue crack growth behavior, we used different thickness specimen 0.9mm and 2.0mm, and variable overload ratio applied fatigue crack propagation test. Also we used finite element analysis for investigating the plastic zone size of crack tip when single overload applied

• 한국정보시스템학회지:정보시스템연구
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• 제25권4호
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• pp.163-179
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• 2016

Purpose This study investigates the associations between SNS fatigue and stress of smartphone SNS, with SNS characteristics. The study focuses on two types of SNS characteristics: information and systems characteristics. We examine SNS stress factors that includes the communication and system overload. Design/methodology/approach To test the proposed hypotheses, the study conducted structural equation modeling with Smart PLS 3.0. The study conducted A sample of 286 participants was collected from SNS users. Findings The results indicated that the information relevance in the information characteristics had an effect on the communication overload, but it had not an effect on the system overload. The information accuracy had an effect on the communication and system overload. The app pace of change influenced the communication and system overload, but the app complexity influenced the system overload. Finally, the SNS stress showed significant relationship with SNS fatigue. The academic and managerial implications were discussed based on the this results.

• 대한기계학회논문집
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• 제16권9호
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• pp.1605-1614
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• 1992

본 연구에서는 고장력 7075-T73 알루미늄합금에 대하여 변동하중의 기보파형 인 단일과대하중과 고-저(high-low) 블럭하중하의 지연거동에 미치는 과대하중비 %O.L., 기준응력확대계수범위 .DELTA. $K_{b}$ 및 무차원 균열깊이 a/W의 영향을 규명하였 으며, 또한 Wheeler모델의 수정에 의한 예측피로수명을 실험치와 함께 검토하였다.다.

• 한국정밀공학회지
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• 제34권3호
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• pp.179-184
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• 2017

Recently, traffic accidents and damage on the highway have increased because of overloaded vehicles. The existing overload-detecting system has a low accuracy rate. An overload-detecting system using a weigh-in-motion (WIM) system has been developed to solve this problem. The WIM system can be used to detect overloaded vehicles by measuring the weight of the vehicles. The WIM system is divided into high-speed and low-speed types. The inaccuracy rate in the low-speed WIM system results mainly from the low response rate of the sensor when the velocity is moving at more than 20 km/h. In this study, a low-speed overload-detecting pad with a hydraulic structure using a WIM system was developed to make the system more accurate. The structural and formal analysis was carried out by using a finite element method (FEM) in order to analyze the structural stability and the extrusion velocity of the system. In addition, a static load test was performed to confirm the linearity and accuracy of the pad.

• 산업과 과학
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• 제3권3호
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• pp.20-28
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• 2024

본 연구는 IT 종사자들의 업무과부하와 이직의도 간의 관계에서 직무소진의 매개효과를 검증하고자 하였다. 이를 위하여 IT 종사자 499명에게 직무요구, 직무소진(하위요인: 정서적 소진, 냉소, 직업 효능감) 및 이직의도 척도로 구성된 온라인 설문을 실시하였다. 수집된 자료는 SPSS 25.0 프로그램을 활용하여 통계 분석하였고, 매개효과 검증을 위해 Sobel test를 실시하였다. 연구결과, 업무과부하는 정서적 소진, 냉소, 이직의도에 유의한 정적 상관성을 보였다. 업무과부하는 정서적 소진과 이직의도에 유의한 정적 영향을 미치는 것으로 나타났다. 업무과부하와 이직의도 간의 관계에서 정서적 소진의 완전 매개효과가 검증되었다. 연구결과를 기반으로, IT 종사자들의 업무과부하와 이직의도 문제를 예방하기 위해서는 정서적 소진에 개입할 필요성을 논의하였다. 마지막으로 IT 종사자들의 직무소진에 개입할 인적 관리 방안과 향후 연구 방향을 제안하였다.