• 한국항공우주학회지
• /
• 제50권10호
• /
• pp.729-737
• /
• 2022

하반기에 발사 예정인 차세대소형위성2호(NEXTSat-2)에 탑재된 고상-액상 상변화물질 열제어장치(Phase Change Material Thermal Control Unit, PCMTCU)의 비행모델에 대한 위성 차원 열진공시험 결과로부터 융해-응고에 따른 작동과정을 분석하였다. 시험결과 PCM의 상변화는 발열부품의 온도 안정화에 기여함을 확인하였다. 시험에서 계측된 온도변화를 이용하여 타당한 정도의 정확도를 갖도록 PCMTCU의 열해석모델에 대한 보정을 수행하였다. 보정된 열해석모델로써 임무궤도의 정상 작동에 따른 PCMTCU의 주기적 온도변화를 예측하였으며, PCM의 액상분율로써 정량적 기여도를 평가하였다. 향후 임무궤도에서의 비행자료를 수신하여 PCMTCU의 우주 환경 검증을 완료할 예정이다.

• 지질공학
• /
• 제24권3호
• /
• pp.333-341
• /
• 2014

The construction of roads, tunnels, and bridges results in changes to the local terrain that may influence the ground safety factor, which represents the stability of geotechnical structures. In this study, we assessed construction sites that had collapsed as a result of terrain change, and then simulated variation in the ground safety factor with respect to terrain change caused by road construction. We assumed steep slopes to simulate changes in terrain in a mountainous area and assumed that earthworks took place for road construction by cutting a platform into the slope and altering the slope angle of the terrain both above and below the road. We calculated values of the ground safety factor through a stability analysis of the slope both above and below the road, and examined the variation in the safety factor of the above- and below-road slopes with respect to changes in road width. We found that if the slope angle was the same above and below the road, then the change in the ground safety factor during/after road construction occurred in the slope below the road, and if the slope angle above the road differed from that below, then the change occurred in both the above- and below-road slopes. Furthermore, the ground safety factor was essentially constant for road widths exceeding 2-6 m, depending on both above- and below-road slope angle. The findings of this study can be used to guide the management of construction sites and to assess changes in ground stability during road construction work, particularly in the early stages of earthworks, when the road width is narrow.

• Applied Biological Chemistry
• /
• 제49권2호
• /
• pp.158-162
• /
• 2006

두부의 저장 중 신선도를 판정 할 수 있는 신선도표시계를 제작하여 두부의 표면에 부착하여 품질변화를 측정하였다. 부패시점을 판정하기 위하여 pH, VBN, TBARS, 총균수 및 관능검사를 수행하였다. 두부의 저장 중 품질변화를 측정한 결과 신선도표시계의 반응 시점과 같은 저장 8일째에 두부는 부패초기수준에 도달하여 pH는 5.6, 총균수는 7.63 log CFU/g의 값을 나타내었다. 또한 VBN, TBARS 값도 상승하였고, 관능검사 결과도 저장 8일 이후에는 이취 및 표면에 점질물 생성 및 조직의 저하 등 가식이 불가능 하였다. 따라서 본 연구에서 사용된 신선도표시계는 두부의 저장 중 신선도를 실시간으로 나타내줌으로써 두부의 유통기한 확립 측면에서 매우 유용한 도구가 될 것으로 판단된다.

• 한국융합학회논문지
• /
• 제8권3호
• /
• pp.1-13
• /
• 2017

본 연구의 목적은 테크노 스트레스 유발요인의 인구통계학적 차이를 살펴보기 위해 수행되었다. 그동안 테크노 스트레스에 영향을 미치는 다양한 요인에 대한 실증연구가 수행되었으나, 근본적 영향을 미친다고 알려져 있는 인구통계학적 요인들에서 어떠한 차이가 있는지에 대한 연구는 수행되지 않았다. 따라서 본 연구는 테크노스트레스 유발요인이 그동안 학자들이 주장해온 인구통계학적인 요인 중에서 성별, 연령, 교육수준, 컴퓨터 사용시간, 직위, 컴퓨터 지식 등에서 각각 어떠한 차이를 나타내는지 실증 분석을 분석하였다. 각각의 인구통계학적 요인을 모두 2개의 요인으로 구분한 후 독립표본 t-검정을 수행하여 차이를 검정하였다. 분석에 사용된 테크노 스트레스 유발요인은 업무과부화, 사생활 침해, 기술복잡성, 기술변화속도 등 5가지이다. 분석결과, 성별과 직위는 기술변화속도에서 유의한 차이를 나타냈다. 교육수준에서는 업무과부화가 차이가 존재하는 것으로 나타났다. 연령에서는 업무 과부화, 사생활침해, 기술복잡성, 기술변화속도에서 차이가 존재하는 것으로 나타났다. 컴퓨터에 대한 활용 지식에서는 기술복잡성, 직무불안정성, 기술변화속도에서 차이가 존재하였다. 마지막으로 컴퓨터 사용시간에서는 유의한 차이가 존재하지 않았다.

• 한국콘텐츠학회논문지
• /
• 제11권7호
• /
• pp.497-507
• /
• 2011

본 논문은 건축자재들을 컴포넌트와 패턴으로 조립하여 패턴 단위로 건축설계가 효율적으로 이루어질 수 있도록 하는 스틸하우스 설계 인터페이스를 개발한다. 또한 이 기술을 이용하여 건축의 공정에 설계, 분석, 변경정보, 조립 등의 건축설계를 시뮬레이션을 통하여 건축의 손쉬운 변경과 비용을 효과적으로 절감하기 위한 기술을 지원하는 조립 건축설계 시스템 개발을 목적으로 한다. 특히 설계자와 사용자도 패턴을 이용하여 쉽게 건축물을 변경시킬 수 있으며 변경에 따라 필요한 자재들의 패턴 정보와 변경된 건축물의 설계도가 자동 생성된다. 또한 개인의 숙련도나 지식 가시화를 통해 발생할 수 있는 지식검색 역시 구현 목표로 한다.

• Nuclear Engineering and Technology
• /
• 제33권3호
• /
• pp.270-282
• /
• 2001

A simple measure of uncertainty importance based on normalized metric distance to quantify the entire change of cumulative distribution functions (CDFs) has been developed for use in probability safety assessments (PSAs). The metric distance measure developed in this study reflects the relative impact of distributional changes of inputs on the change of an output distribution, white most of the existing uncertainty importance measures reflect the magnitude of relative contribution of input uncertainties to the output uncertainty. Normalization is made to make the metric distance measure a dimensionless quantity. The present measure has been evaluated analytically for various analytical distributions to examine its characteristics. To illustrate the applicability and strength of the present measure, two examples are provided. The first example is an application of the present measure to a typical problem of a system fault tree analysis and the second one is for a hypothetical non-linear model. Comparisons of the present result with those obtained by existing uncertainty importance measures show that the metric distance measure is a useful tool to express the measure of uncertainty importance in terms of the relative impact of distributional changes of inputs on the change of an output distribution.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.493-496
• /
• 2003

Transmittance and resistivity is investigated according to bending of ITO (indium tin oxide)film with four other multi-barrier film. Transmission data of ITO film with four ITO films showed there was about large 90% transmission above 550 nm wavelength at three multi-barrier structures. But, both -side hard coated structure showed relatively low 75% transmission above 550 nm wavelength. Also, resistivity change of four other multi-barrier film showed there was the lowest change at oneside hard coated structure. Subsequently, with result of resistivity change according to position, it was known the resistivity change of the center increased rapidly than that of the edge.

• 반도체디스플레이기술학회지
• /
• 제21권2호
• /
• pp.74-84
• /
• 2022

As the semiconductor industry develops, the difficulty of newly required process technology becomes difficult, and the importance of production yield and product reliability increases. As an effort to minimize yield loss in the manufacturing process, interests in the process defect process for facility diagnosis and defect identification are continuously increasing. This research observed the plasma condition changes in the multi oxide/nitride layer deposition (MOLD) process, which is one of the 3D-NAND manufacturing processes through optical emission spectroscopy (OES) and monitored the result of whether the change in plasma characteristics generated in repeated deposition of oxide film and nitride film could directly affect the film. Based on these results, it was confirmed that if a change over a certain period occurs, a change in the plasma characteristics was detected. The change may affect the quality of oxide film, such as the film thickness as well as the interfacial surface roughness when the oxide and nitride thin film deposited by plasma enhenced chemical vapor deposition (PECVD) method.

• 한국가시화정보학회지
• /
• 제22권2호
• /
• pp.104-114
• /
• 2024

To effectively control heat generation resulting from advancements in fast discharging technology for electric vehicle batteries, hybrid Battery Thermal Management Systems (BTMS) are gaining attention. In this study, a BTMS combining Phase Change Material (PCM) with Oscillating Heat Pipe (OHP) was designed. During the phase change process of the PCM, the maximum battery temperature increased slowly. Additionally, due to the excellent heat transfer capability of the OHP, the PCM/OHP BTMS delayed the time when the maximum battery temperature exceeded 50 ℃ by 810 s compared to the PCM/copper fin BTMS, resulting in the maximum battery temperature that was 41.29 ℃ lower at 3600 s. Furthermore, in the section where the latent heat of the PCM had the greatest impact, the slope of the battery temperature difference was 0.0017 lower than that of the PCM/copper fin BTMS. Therefore, the PCM/OHP BTMS demonstrates its potential as a viable hybrid BTMS.

• 산경연구논집
• /
• 제11권4호
• /
• pp.7-18
• /
• 2020

Purpose: This research investigates the impact of technology adoption on organisation productivity. The framework has three independent variables viz. technological change, information technology (IT) infrastructure, and IT knowledge management and one dependent variable as organisational productivity. Research design, data and methodology: An explanatory research design with a quantitative research method was employed, and data was collected using a self-administered questionnaire using online as well as an offline survey. The sample consisted of 300 IT managers and senior-level executives (production as well as service team) in leading IT companies in Malaysia selected using snowball sampling. Normality and reliability assessment was performed in the first stage utilising SPSS 22, and Confirmatory Factory Analysis (CFA) was performed with maximum likelihood estimation to assess the internal consistency, convergent validity, and discriminant validity. Finally, Structural Equation Model (SEM) and path analysis are conducted using AMOS 22. Results: The research findings demonstrated that technological change and IT infrastructure positively and significantly impact the organisation's productivity while IT knowledge management has significant but negative impact on organizational productivity of IT companies in Malaysia. Conclusion: The research concludes that all three factors plays important role in deciding organizational producvity. Recommendations, implications, limitations and future research avenues are discussed.