• 대한전기학회논문지:전력기술부문A
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• 제55권1호
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• pp.37-44
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• 2006

In this paper we explore the susceptibility of common sensitive loads by voltage sags of power distribution systems. The experimental approach was used for obtaining the susceptibility of single-phase loads and the three-phase induction motor. The experimental result of single-phase loads was transformed to the ITIC(Information of Technology Industry Council) format and used for evaluating the adverse impacts of a individual and repetitive sags using the performance contour of the foreign standard data. In order to assess the impact of voltage sags on three-phase induction motor, also, the experiment was peformed. The experiment was focused on the current, torque, and speed loss of the motor during a voltage sag. For comparing the impacts of individual and repetitive voltage sags, the variations of motor torque is focused among the experimental results. The sensitive curves of instantaneous current peak are used to describe the susceptibility of three-phase induction motor and 진so it were used for the quantitative analysis of the impact of three-phase induction motor due to voltage sags. Through the results of experiment, we verified that some types loads have more severe impact at repetitive voltage sags than individual ones and proposed method can be effectively used to evaluate the actual impact of voltage sags.

• 대한조선학회논문집
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• 제49권4호
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• pp.281-286
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• 2012

Single frame structures with notches were fractured by applying drop impact loadings at room temperature and low temperature. Johnson-Cook shear failure model has been employed to simulate the fractured single frame structures. Through several numerical analyses, material constants for Johnson-Cook shear failure model have been found producing the cracks resulted from experiments. Fracture strain-stress triaxiality curves at both room temperature and low temperature are presented based on the extracted material constants. It is expected that the fracture strain-stress triaxiality curves can offer objective fracture criteria for the assessment of structural fractures of polar class vessel structures fabricated from DH36 steels. The fracture experiments of single frame structures revealed that the structure on low temperature condition fractures at much lower strain than that on room temperature condition despite the same stress states at both temperatures. In conclusion, the material properties on low temperature condition are essential to estimate the fracture characteristics of steel structures operated in the Northern Sea Route.

• 대한기계학회논문집A
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• 제26권12호
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• pp.2656-2661
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• 2002

Multiple impact models to examine the effect of stress interference are proposed and investigated. The single shot model analysis, which used various shot ball conditions, was carried out to compare with multiple impacts analysis. Then the multiple impact analysis were performed to predict the effect of the shot ball distances. The results showed that the stress interference in the multiple impact model significantly reduced the maximum value of the compressive residual stresses. The residual stress profiles were strongly effected by the shot ball distances. The multiple impact model can simulate a realistic shot peening process rather than a single shot model does. It is concluded that the proposed model predicts the real process more accurately.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 공동학술발표회
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• pp.251-251
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• 2017

• 제어로봇시스템학회논문지
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• 제5권8호
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• pp.955-960
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• 1999

This paper describes the effect of impact configurations on a single robot manipulator. The effect of different configurations of kinematically redundant arms on impact forces at their end effectors during contact with the environment is investigated. Instead of the well-known impact ellipsoid, I propose an analytic method on the geometric configuration of the impact directly from the mathematical definition. By calculating the length along the specified motion direction and volume of the geometry, we can determine the characteristics of robot configurations in terms of both the impact along the specified direction and the ability of the robot withstanding the impact. Simulations of various impact configurations are discussed at the end of this paper.

• 정보관리학회지
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• 제32권4호
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• pp.205-221
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• 2015

학술지의 인용빈도를 특정하여 산출된 지수로 단일 논문의 영향력을 평가하는 것에 대한 비판으로 인해 단일 논문의 인용 영향력을 측정하는 인용지수에 대한 연구가 다양하게 시도되었다. 이 연구에서는 8개의 단일 논문 인용영향력 평가 지수를 살펴보고 KCI 논문 데이터베이스를 대상으로 각 인용지수의 분야별 편향성을 조사하여 보았다. 대상 지수는 단순 인용빈도, 페이지랭크, f-값, CCI, c-지수, 단일문헌 h-지수, 단일문헌 hs-지수, cl-지수였다. 분석결과 페이지랭크가 학문 분야별 균등성, 학문 분야 내에서 학술지별 균등성 영역에서 가장 편향성이 없는 것으로 나타났다. 반면에 단순 인용빈도는 특정 학문분야나 특정 학술지에 편향된 결과를 산출할 가능성이 높은 것으로 나타났다. KCI 데이터베이스에서는 논문의 단순 인용빈도만 제공하고 있는데, 분야별 균등성을 가장 잘 유지하는 지수인 논문 페이지랭크를 함께 제공할 필요가 있다. 아울러 인용한 문헌의 인용빈도만으로 산출이 가능해서 이용자의 검색 결과로부터 바로 산출할 수 있는 지역 네크워크 지수 중에서는 cl-지수가 가장 균등성을 잘 유지하므로 계산 과정과 서비스가 손쉬운 지수로 함께 제공하는 것도 검토해야 한다.

• 한국안전학회지
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• 제33권5호
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• pp.120-126
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• 2018

The traffic accident types are largely classified into vehicle to vehicle accident, vehicle-to-person accident and single-vehicle. Especially, the single-vehicle accident types are severe when the vehicle crashed into road facilities such as bridge, piers, utility poles. The severity of single-vehicle accidents are ten times higher than that of all other accidents types. It is needed to consider to reduce accident severity. This study was conducted to develop crash worthy safety design facility to ensure the vehicle occupant safety. The simulation and the crash tests were conducted for assessment of the safety performance to check the criteria of CC2(Crash Cushion 2) level. THIV(Theoretical Head Impact Velocity) and PHD(Post-impact Head Deceleration) were used to assess occupant impact severity for crashes. The non-redirection collision test conditions for 900 kg and 1,300 kg-head on crash tests, 900 kg-1/4 offset crash tests, 1,300 kg-head on crash test with $15^{\circ}$angle were conducted. The simulation and experiment test result showed that THIV values were below 44 km/h criterion, PHD values were below the 20G. The development non-redirective crash cushion is expected to be used for the fixed object such as bridge piers for assuring occupant safety.

• 소성∙가공
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• 제23권6호
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• pp.363-368
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• 2014

Electromagnetic forming(EMF) is one of the high-speed forming methods, and has been used to deform metal sheets. The advantages of electromagnetic forming are reduced wrinkling due to non-contact characteristic and fine formability because of the high speed impact. In the current study, we suggest the application of electromagnetic forming to emboss pattern shapes using electromagnetic forces with only one forming coil and one punch. The high impact of the sheet at speeds of 100~300m/s produces significant coining pressure. In the current paper, electromagnetic forming was applied to Al 1100-O sheets; with thickness of 1.27mm and an area of $40mm{\times}40mm$. Using a single spiral coil, totally different types of patterns were created. Four different patterns were successfully produced on the aluminum sheet. The length and depth of the patterns were measured by three-dimensional scanning. Comparisons to the die shape showed good agreement. The test results confirm that emboss pattern forming by EMF using a single die can be used to replace the costly conventional method.

• 산경연구논집
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• 제11권10호
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• pp.17-25
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• 2020

Purpose: The purpose of this study is to narrow the target down to college students representing single-person households to identify the main attributes of their choice of Home Meal Replacement(HMR) and to look at the impact on satisfaction and repurchase intentions. Research design, data and methodology: An online survey was conducted for consumers who purchased HMR products at least once and a total of 264 questionnaires were used for demonstration analysis. The collected data have verified for validity and reliability between measurement variables through exploratory factor analysis and reliability analysis. Results: As a result, curiosity, economy, safety, and brand, which are HMR selection attributes that university students' value, have a significant impact on satisfaction, and satisfaction has a significant impact on the intention of repurchase, a variable of behavior. In addition, the adjustment effect of health value pursuit was significant only in safety attributes. Conclusions: This study divided the target group to examine what the HMR selection attributes of single-person college students are, the main consumer of HMR, and how selective attributes affect satisfaction and willingness to repurchase. In the process, we wanted to find out if there was a moderating effect on the health-oriented values in the dietary lifestyle.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.728-731
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• 1995

Miniaturzed specimen technology permits mechanical bechanical behavior to be determined using a minimum volume of material. because it is almost impossible to sample the conventional specimen for the fracture toughness test without damage to the rotor. In addition, it is different to collect a large amount of actual turbine rotor steels. Hence seven kinds of specimen with different degradation levels were prepared by isothermal aging heat treatment at 630 .deg. C. Test material was 1Cr-1Mo-0.25V steel which was widely used for turbine rotor material. The relation between fracture toughness and DBTT was investigated The characteristics of minaturized impact speciments technique was discussed. Finally, the estimating method of fracture toughness using a single impact specimen was introduced.