• 동력기계공학회지
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• 제17권5호
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• pp.44-51
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• 2013

This paper proposes and analyzes recycling of optical phonons emitted by nonradiative decay, which is a major thermal management concern for high-power light emitting diodes (LED), by introducing an integrated, heterogeneous barrier cooling layer. The cooling is proportional to the number of phonons absorbed per electron overcoming the potential barrier, while the multi-phonon absorption rate is inversely proportional to this number. We address the theoretical treatment of photon-electron-phonon interaction/transport kinetics for optimal number of phonons (i.e., barrier height). We consider a GaN/InGaN LED with a metal/AlGaAs/GaAs/metal potential barrier and discuss the energy conversion rates. We find that significant amount of heat can be recycled by the barrier transition cooling layer.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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• pp.169-174
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• 1998

An 1200-day time-dependent fuel-management for the transition from 37-element fuel to CANFLEX-NU fuel in a CANDU 6 reactor has been simulated to show the compatibility of the CANFLEX-NU fuel with the reactor operation. The simulation calculation were carried out with the RFSP code, provided by cell averaged hel properties obtained from the POWDERPUFS-V code. The refueling scheme for both fuels was an eight bundle shift art a time. The simulation results show that the maximum channel and bundle powers were maintained below the licence limit of the CANDU 6. This indicates that the CANFLEX-NU fuel bundle is compatible with the CANDU 6 reactor operation during the transition period.

• 한국물환경학회지
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• 제30권4호
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• pp.429-440
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• 2014

This study was conducted to investigate the main cause of water quality deterioration during the spring season in the transition zone between the South Han River and the river-reservoir Paldang. A water quality model modified from QUAL2E (U.S.EPA) was used, and the model showed that eutrophication and algal production in the low flow season affected about 60% of the organic pollution at the downstream of the South Han River. This result means that phosphorus control is prior to external organic material management to ameliorate the deterioration of water quality in the water body.

• 산업공학
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• 제13권4호
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• pp.694-702
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• 2000

For the graceful transition from the analog to digital TV systems, a systematic frequency assignment scheme must be incorporated into the transition planning procedure. In this study, we have studied the frequency assignment methodology for the efficient management of the limited spectrum resources. By applying the graph-theoretic approach, this study developed a new solution method for additional frequency assignment problem whose objective is to assign available frequencies for newly generated requirements (digital TV stations) with minimum reassignment of the preassigned frequencies to LPTV stations while meeting the interference-related constraints. The proposed algorithm can be effectively applied not only to the current digital TV introduction phase but also to the development phase with some further development. This study can be utilized as the basis for the future study on frequency assignments that aims at graceful transition from analog TV to digital TV.

• Industrial Engineering and Management Systems
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• 제12권2호
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• pp.143-150
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• 2013

The number of airline passengers in China has rapidly increased, so understanding the relationship between brand equity of airlines in China and ticket purchase intention of Chinese passengers is important for airline business success in China. Using the structural equation modeling, this study explores the relationships among determinants of brand equity as well as the relationships between brand equity, transition cost, and purchase intention. The major findings are: brand equity of airlines directly influences purchase intention; transition cost directly influences brand equity; and transition cost indirectly influences purchase intention in China. In addition, the results show that marketing strategies using the airline brand can be more effective for certain customer groups, including high income customers, married customers, government servants, and businessmen.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.854-861
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• 2005

The functional behavior of a portable consumer electronic (PCE) product is nearly all expressed with human-machine interaction (HMI) tasks. Although physical prototyping and computer aided design (CAD) software can show the appearance of the product, they cannot properly reflect its functional behavior. In this paper, we propose a virtual prototyping (VP) system that incorporates virtual reality and HMI functional simulation in order to enables users to capture not only the realistic look of a PCE product but also its functional behavior. We obtain geometric part models of the product and their assembly and kinematics information with the help of CAD and reverse engineering tools, and visualize them with various display tools. We adopt state transition methodology to capture the HMI functional behavior of the product into a state transition chart, which is later used to construct a finite state machine (FSM) for the functional simulation of the product. The FSM plays an important role to control the transition between states of the product. The proposed VP system receives input events such as mouse clicks on buttons and switches of the virtual prototype model, and it reacts to the events based on the FSM by activating associated activities. The VP system provides the realistic visualization of the product and the vivid simulation of its functional behavior. It can easily allow users to perform functional evaluation and usability testing. Moreover, it can greatly reduce communication errors occurring in a typical product development process. A case study about VP of an MP3 player is given to show the usefulness of the proposed VP system.

• 과학기술학연구
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• 제8권1호
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• pp.1-28
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• 2008

이 글에서는 새롭게 등장하고 있는 사회적 목표를 지향하는 혁신정책의 특성들을 살펴보고 그것이 우리의 혁신정책에 주는 함의를 살펴보았다. 우선 이 정책들은 지속가능성과 같은 목표를 제시하고 그것에 경제성장보다 앞서는 우선권을 부여하고 있다. 또 이 정책들은 개별적인 기술개발이나 국지적인 문제해결을 넘어 사회 기술시스템 전체의 전환(system transition)을 염두에 두고 있다. 그리고 시스템 전환을 위해, 새로운 내용을 갖는 기술과 사회제도를 실험하여 기술적 지식을 확충하고 정당성을 향상시키는 '전략적 니치 관리' 방식을 채택하고 있다. 장기적이고 근본적인 변화 방향과 구체적이고 국지적인 정책과 사업들을 학습 과정을 통해 연계시키고 있는 것이다. 이와 함께 정책들의 기획 및 집행과정에서 공공적 참여자의 역할을 확대하고 있다. 이런 정책이 우리에게 주는 함의는 2007년에 발표된 "기술기반 삶의 질 향상 종합대책"을 중심으로 논의하였다. 이 대책은 경제성장 중심 혁신정책의 틀을 넘어서는 새로운 정책이었지만 기존 정책들의 관성으로 인해 몇 가지 한계가 있음을 지적하였다. 특히 과거 산업화 과정에서 형성된 타겟팅적 경향 때문에 장기적 관점에서 시스템 전환을 고려하는 관점이 도입되는 데 어려움이 있다는 것을 논의하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.155-155
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• 2022

Low head, ogee spillways is popularly used to defense against floods as well as to provide water for irrigation. Spillway is also used to assess compliance with water quality regulations by controlling amount of discharge to the downstream of a channel. For the purpose of water resource management and/or environmental aspects as explained above, the flow discharge through spillways need to be correctly rated as a function of geometry and hydraulic variables. Typically, four flow conditions are encountered during the operation of spillway: (a) uncontrolled free flow (UF); (b) uncontrolled submerged flow (US); controlled free flow (CF); and controlled submerged flow (CS), and each condition has a unique rating equation. However, one of the tricky part of the spillway operation is finding correct flow type over the spillway because structures can operate under both submerged and free flow conditions, and the types are continuously changing over time depending on the amount of discharge, head water and tail water elevation. Quite obviously, if the wrong rating curve relationship is applied because of misjudgment of the flow type due to a transition, a serious error can occur. Thus, an hydraulic model study of one of spillway structure located in South Florida was conducted for the purpose of developing transition relationships. In this presentation, US to UF transition is highlighted.

• 임상간호연구
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• 제25권3호
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• pp.237-250
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• 2019

Purpose: The aim of this study was to investigate the satisfaction of newly graduated nurses with educational programs and their experiences in role transition. Methods: Data were collected from November 1 to December 15, 2018 and 483 new graduate nurses working at 15 tertiary hospitals and 10 general hospitals participated. For data collection, self-report questionnaires including the Casey-Fink Graduate Nurse Experience Survey tool and satisfaction with education were used. Data were analyzed using descriptive statistics, t-test, and one-way analysis of variance. Results: Satisfaction with education ranged from 3.09 to 3.27, and satisfaction with preceptors was 3.45(maximum 4). The skill that new nurses ranked as most difficult during the first 3 months was charting/documentation, and throughout a whole year, the top 4 difficult skills were cardiopulmonary resuscitation/emergency response, ventilator care, end-of-life care, and prioritization/time management. In comfort/confidence, new graduates felt most comfortable with support and least comfortable with patient safety. More than 50 percent of new graduates experienced stress during role transition, and the most frequently experienced stressors were related to job performance and personal life. Levels of satisfaction with education and comfort/confidence differed according to the hospital type and number of preceptors for new nurses. Conclusion: In order to facilitate the transition of new graduate nurses to professional nurse, an extended period of education, systematic and standardized transition programs, and continuous support during the first year of practice are required.

• 디지털융복합연구
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• 제17권9호
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• pp.221-229
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• 2019

본 연구는 간호대학생의 간호역량 및 감성지능과 간호사 역할 이행의 관계를 파악하기 위해 실시하였다. 연구대상은 충남 소재 4년제 대학 간호학과에 재학 중인 3,4 학년 학생 134명이다. 자료수집은 자가보고형 설문지를 이용하여 2018년 11월 1일에서 12월 10일까지 실시하였으며, 수집된 자료는 SPSS 20.0 program을 이용하여 분석하였다. 연구결과 간호대학생의 간호역량(r=.79, p<.001)과 감성지능(r=.59, p<.001)이 높을수록 간호사 역할 이행 정도가 높게 나타났다 간호대학생의 간호사 역할 이행 영향 요인은 간호역량(${\beta}=.66$, p<001)과 감성지능(${\beta}=.22$, p=.001) 순이었으며, 설명력은 67.8%이었다. 따라서 간호대학생의 간호사 역할 이행 증가를 위해 간호역량 및 감성지능 증가를 위한 중재 프로그램을 제공하는 것이 필요하며 제공된 프로그램에 대한 효과 평가를 통해 효율적인 프로그램이 제공될 수 있도록 하는 것이 필요하다고 할 것이다.