• 한국초전도ㆍ저온공학회논문지
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• 제17권3호
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• pp.37-40
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• 2015

Recently, the electrical insulation design for electrical apparatuses is important to cope with the tendency of high voltage. The degradation characteristics of a superconducting coil due to an electrical breakdown should be considered to design a high voltage superconducting coil. In this paper, the degradation characteristics of 2G high temperature superconducting (HTS) wires are studied with respect to electrical breakdown tests. To analyze the dependency of the degradation characteristics of 2G HTS wires, the electrical breakdown tests are performed with AC(alternating current) and DC(direct current) voltage. All tests are performed by applying various magnitudes of AC and DC breakdown voltages. To verify the degradation characteristics of 2G HTS wires, the tests are performed with various 2G HTS wires with respect to stabilizer materials. The degradation characteristics of 2G HTS wires, such as Ic(critical current) and index number are measured by performing electrical breakdown tests. It is found that the characteristics such as Ic and index number can be degraded by an electrical breakdown. Moreover, it is concluded that the degradation characteristics of 2G HTS wires are affected by the stabilizer material and applied voltages. The cross-sectional view of 2G HTS wires is observed by using a scanning electron microscope (SEM). As results, it is found that the degradation characteristics of 2G HTS wires are concerned with hardness and electrical conductivity of stabilizer layers.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.798-799
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• 2016

기존의 시약장의 경우 시약들을 성상 별로 분류하지 않고 관리하게 되면 위험 상황이 발생할 수 있는 문제점이 있다. 또한 위험 상황 발생 시 외부에서 시약장을 제어할 수 있는 기능이 미비한 실정이다. 본 논문에서는 시약들을 관리하기 위해 성상 별로 분류하고 모바일 디바이스에서 시약장을 관리할 수 있는 시스템을 설계한다. 성상 분류를 통해 제 1류에서 제 6류까지 각 시약들을 분류에 맞게 관리하고 모바일 디바이스에서는 센서 제어, 시약 및 센서 데이터 모니터링, 위험 상황 발생 시 알람 메시지를 전송한다. 이로 인해 성상 분류를 통하여 연구실 내 사고를 줄이고 위험 상황 발생 시 외부에서도 신속한 대처가 가능할 것으로 사료된다.

• 항공우주시스템공학회지
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• 제13권4호
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• pp.37-42
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• 2019

본 논문에서는 장치의 유연성과 소형화를 위해 EHD 잉크젯 프린팅 기술을 이용하여 은 나노 잉크의 굽힘 특성을 확인하였다. EHD 기술을 위한 최적조건을 도출하였고 은 나노 회로의 굽힘 특성을 파악하였다. EHD 프린팅을 위해서는 재료 특성, 밀도, 유량, 전압, 토출 높이 등 각 파라미터 별 최적점을 찾아내는 것이 필수적이므로 작동 높이와 인가 전압에 따른 각각의 최적점을 도출하였다. 또한, 제작한 굽힘 장치를 통해 각 곡률 반경 별 저항을 측정하여 굽힘 특성을 알아보았고, 곡률이 증가함에 따라, 저항변화율이 급격히 증가하는 것을 확인하였다.

• 한국정보시스템학회지:정보시스템연구
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• 제31권2호
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• pp.63-88
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• 2022

Purpose The purpose of this study is to empirically analyze the factors affecting the intention to use cloud computing in the smart work environment. This study is meaningful in that it examines the characteristics of smart work and the fit of cloud computing characteristics, and it is a study that reveals the factors affecting the intention to use cloud computing by applying the integrated model of TTF and TAM. Design/methodology/approach In order to understand the factors affecting the intention to use cloud computing in the smart work environment, a research model that integrates TTF and TAM with the hypothesis was proposed. In order to verify the research hypothesis, this study conducted a survey on individuals with experience in smart work and cloud computing. And with the data 280 collected in the survey, path analysis was performed using the PLS structural equation. Findings As a result, it was found that task characteristics and technology characteristics had a positive (+) effect on task-skill fit, and task-skill fit had a positive (+) effect on perceived ease of use and usefulness. Also, task-skill fit, perceived ease of use, and perceived usefulness were found to have a positive (+) effect on intention to use.

• Geomechanics and Engineering
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• 제28권2호
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• pp.171-180
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• 2022

Time-dependent stress-strain behaviour significantly influences the compressibility characteristics of the clayey soil. In this paper, a series of oedometer tests were conducted in two loading patterns and investigated the time-dependent compressibility characteristics of Indian Montmorillonite Clay, also known as black cotton soil (BC) soil, during loading-unloading stages. The experimental data are analyzed using a new non-linear function of the Elasto-Visco-Plastic Model considering Swelling behaviour (EVPS model). From the experimental result, it is found that BC soil exhibits significant time-dependent behaviour during creep compared to the swelling stage. Pore water entrance restriction due to consolidated overburden pressure and decrease in cation hydrations are responsible factors. Apart from it, particle sliding is also evident during creep. The time-dependent parameters like strain limit, creep coefficient and C_αe/C_c are observed to be significant during the loading stage than the swelling stage. The relationship between creep coefficients and applied stresses is found to be nonlinear. The creep coefficient increases significantly up to 630 kPa-760 kPa (during reloading), and beyond it, the creep coefficient decreases continuously. Several parameters like loading duration, the magnitude of applied stress, loading history, and loading path have also influenced secondary compressibility characteristics. The time-dependent compressibility characteristics of BC soil are presented and discussed in detail.

• 한국정밀공학회지
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• 제20권7호
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• pp.128-137
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• 2003

Continuously variable damper can yield diverse damping forces for a single damping velocity. It is widely used in the semi-active suspension system since, with right control logics, it can enhance ride comfort compared to the passive damper while not degrading driving safety. A key to the successful design of the continuously variable damper is the knowledge of its complex and nonlinear characteristics. In this paper, research has been done for analyzing characteristics of the continuously variable damper. Various damper components have been investigated and their effects upon the force-velocity characteristics of the damper have been examined. The effects of the damper characteristics change upon ride comfort and driving safety have also been investigated by numerical simulations.

• 전기학회논문지P
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• 제65권1호
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• pp.57-65
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• 2016

This paper was analyzed the characteristics of piezoelectric inkjet print head using finite element method(FEM). It showed the bending node driving of piezoelectric and relation theory principle consider piezoelectric material characteristics and ink characteristics. From such result we were had the piezoelectric head design and manufacture. It got a this head characteristics through experiment, we confirmed that proper voltage control is possible to through ink drop control experiment of piezoelectric print head. This paper was obtained the suitable ink jetting characteristics that manufacture the control circuit and piezoelectric inkjet print head. This practice product was applied to improvement of PCB electric circuit pattern by etching resist ink that PCB manufactured to complex process over traditional 6 stages can be simpled to 1 stage by inkjet printing technology.

• Asia pacific journal of information systems
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• 제3권2호
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• pp.117-144
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• 1993

MIS researches involve, in particular, the problems of developing appropriate IS for given MIS environments and lay emphasis on identifying prominant IS characteristics pertaining to the system in issue. This study deals with the IS characteristics for the management task of "planning". It investigates empirically the impacts of IS characteristics, under a set of proposed hypotheses, with particular respect to users' information satisfaction and performance in carrying out the task of planning. Futhermore, it examines whether the IS characteristics have different effects depending on the planning modes on the part of IS users. Based on a group of hypotheses accepted, the IS characteristics for planning decision making are not only proposed according to planning modes: preactive, reactive and proactive, but also classified into six subsystem categories: input, process, ouput, storage, interface and communication. Finally, the implications of the findings are discussed.

• Tribology and Lubricants
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• 제18권5호
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• pp.339-344
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• 2002

Whenever moving surfaces of machine driving elements interact in air and lubricating oil, oxidization film on the surfaces are generated. It is effect to prevent friction and wear on contact area. Since the electronic current progress the oxidization of metal, if the electronic flow be regulated, the thickness of oxidization film can be regulated and friction characteristics can be improved. But the electronic current can deteriorate friction characteristics, so various characteristics must be investigated on transforming of electronic current. Therefor, using the Norton equation in this study, short current were transformed between frictional materials using ball on disk type tester. It was studied on effect of electronic current for friction characteristics.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.841-848
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• 2008

This paper examined dynamic characteristics of high speed trains using a time varying frequency transform. Fourier transform based methods are frequently used for the calculation of the dynamic characteristics of trains in the frequency domain, but they cannot represent the time-varying characteristics. Therefore it is necessary to examine their characteristics using a time-varying frequency transform. For the examination, the non-stationary vibration of wheelset, bogie, and carbody are measured using accelerometers and stored in a data aquisition system. They are processed with localization of the data by modulating with a window function, and Fourier transform is taken to each localized data, called the short-time Fourier transform. From the processed results, time varying auto-spectral density, cross-spectral density, frequency response, and coherence functions have been calculated. From the analysis, it is confirmed that the time varying frequency transform is a useful method for analyzing the dynamic characteristics of high speed trains.