• Smart Structures and Systems
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• 제12권5호
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• pp.579-594
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• 2013

A new enthalpy - based procedure for the homogenization of the electromechanical material parameters of composite piezoelectric modules with integrated electrodes is presented. It is based on a finite element (FE) modeling of the latter's representative volume element (RVE). In contrast to most previously published homogenization approaches that are based on averaged quantities, the presented method uses a direct evaluation of the electromechanical enthalpy. Hence, for the linear orthotropic piezoelectric composite behavior full set of elastic, piezoelectric, and dielectric material parameters, 17 load cases (LC) are used where each load case leads directly to one material parameter. This gives the possibility to elaborate a very strict and easy to program processing. In conjunction with the 17 LC, the enthalpy - based homogenization is particularly suitable for laminated composite piezoelectric modules with integrated electrodes. In this case, the electric load has to be given at the electrodes rather than at the RVE FE model boundaries. The proposed procedure is validated through its comparison to literature available results on a classical 1-3 piezoelectric micro fiber (longitudinally polarized) reinforced composite and a $d_{15}$ shear piezoelectric macro-fiber (transversely polarized) composite module.

• Current Photovoltaic Research
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• 제7권3호
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• pp.71-75
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• 2019

Solar energy is one of the renewable energy sources. It can respond to expanding energy demand. A solar cell module is designed to have a durability that can be developed over a long period of 25 years to be installed outdoors and perform like a stable power supply. We need Standard Test Condition (STC)-based power output data before and after testing to measure the power output of existing modules. The modules are shown to reduce power output by comparing data before and after outdoor experiments regardless of whether they are indoor or outdoor. It is easy to compare the power output quantities through the module simulator in the indoor. However, it takes a lot of testing time and costs to compare the power output on outdoor in the case of a high number of modules and distance from the module simulator. It can save time and costs if we can check the power output using the data in outdoor. We have used the long-term outdoor test to find the elements out that corresponds to the reductions in power output quantities. We have conducted research that matched the actual and the tests.

• 방사성폐기물학회지
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• 제4권3호
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• pp.265-273
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• 2006

해체 작업은 최적의 해체시나리오에 따라 경제적이면서 안전하게 수행되어야 하기 때문에 제염해체의 계획단계에서 시나리오의 다양한 관점에서의 평가는 매우 중요하다. 따라서 사전에 해체 시나리오에 대한 평가자료를 산출하기 위한 평가모듈개발이 필요하였다. 본 논문에서는 해체 시나리오의 전체적인 과정을 컴퓨터 가상공간에서 표현하여 해체과정을 이해하고 문제점을 파악하기 위해 디지털 목업 시스템을 구축하였다. 그리고 해체일정과 예상비용을 산출하기 위해 해체작업시간 및 예상비용 산출식을 도출하였다. 그리고 대상물의 방사화 정도를 쉽게 파악하기 위하여 방사화 가시화 모듈을 개발하였다. 마지막으로 전체적인 결과와 다른 여러 중요요소를 기초로 하여 해체 시나리오를 평가하는 방법론에 대해 기술하였다.

• 대한인간공학회지
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• 제29권2호
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• pp.217-224
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• 2010

Research has been conducted to examine the effects of mechanical and sound characteristics of fabrics on affective quality. The present study developed the Affective Quality Evaluation and Estimation System for Textiles (AQEEST) with distinguished features that can be effectively used in the affective research of fabric frictional sound. The AQEEST consists of three subsystems (affective quality evaluation, affective quality estimation, and audible distance estimation subsystems) and each subsystem consists of three to four modules (e.g., evaluation condition setup, evaluation experimentation, and textile database management modules) depending on its functional requirements. The affective quality evaluation subsystem was designed to help administer an experiment in a systematic manner and present acoustic and visual stimuli simultaneously in various gait conditions (walking, jogging, and running) to mimic a more realistic situation of textile frictional sound production. Next, the affective quality estimation subsystem was designed to estimate the sound characteristics, affective qualities, overall psychological satisfaction, and reference cluster of a textile using its mechanical and/or sound characteristic information. Lastly, the audible distance estimation subsystem was designed to estimate the just noticeable sound pressure levels and audible distances of a textile for various gait conditions using its mechanical characteristic information. The AQEEST can be upgraded by accommodating more affective quality study results for various textiles.

• 한국산학기술학회논문지
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• 제22권6호
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• pp.27-35
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• 2021

일반적으로, 태양광모듈은 20년 이상의 장기간 동안 사용할 수 있다고 알려져 있지만, 설치된 주변 환경요인(염분, 온도, 습도, 자외선, 음영 등)에 따라 다양한 열화현상이 발생하여, 전기적 성능과 수명이 크게 감소할 수 있어 태양광 모듈에 대한 정확한 열화특성 분석이 요구되고 있다. 그러나, 태양광모듈의 출력을 STC조건으로 보정하여 초기 사양과 비교분석하는 기존의 열화특성 분석방법은 데이터 보정 시 필연적으로 발생하는 데이터 오류로 인하여 객관성이 결여될 수 있다. 따라서, 본 논문에서는 태양광전원 모듈부와 모니터링부로 구성된 열화진단 시험장치를 구축하여 모듈별 출력 데이터를 측정 및 수집하고, 태양광모듈의 출력 변동성과 통신 에러 및 지연에 따른 영향을 최소화하기 위하여, MATLAB을 이용한 열화특성 분석 모델링을 통하여 실측 데이터를 평활화한다. 또한, 이를 바탕으로 태양광모듈의 열화 상태를 계절별 실측 출력특성에 따라 분석한 결과, 전체 구형모듈의 평균 열화율은 총 25.73%이고, 연평균 1.55%씩 열화됨을 진단할 수 있어, 본 논문에서 구축한 열화진단 시험장치의 유용성을 확인하였다.

• 한국산학기술학회논문지
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• 제18권2호
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• pp.478-483
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• 2017

본 논문에서는 소형 전자기기와 같은 발열부 온도 제어를 위해 압전 소자와 열전 소자를 이용하여 국소부 냉각 성능을 실험적으로 조사해 보았다. 실험은 열전 소자를 이용하여 실험 영역내에 냉각부를 형성하고, 압전 소자에 80Hz와 110Hz 의 인가주파수를 각각 적용하여, 압전 소자를 작동시켰을 때와 작동시키지 않았을 때 열전 소자에 의해 형성된 시험부의 냉각 영역에서 온도 분포를 측정하였다. 또한, 냉각 영역의 온도측정 결과를 토대로 압전 소자를 적용하였을 때와 적용하지 않았을 때 냉각 영역의 성능 계수를 계산하고, 가시화 장치를 구성한 후 시험부내에 냉각 영역의 열유동 현상도 확인해 보았다. 실험결과, 온도분포 측정 실험 결과와 성능 계수 계산 결과로 부터 압전 소자를 작동하지 않은 경우보다 압전 소자를 작동한 경우에서 냉각 성능이 개선되는 것을 확인할 수 있었다.. 또한, 가시화 결과를 토대로 열전 소자에 의해 형성된 냉각 영역에 압전 소자를 작동시켰을 경우에 냉각 영역의 국소부에 압전 소자에 의한 상하 진동의 강제 대류 현상이 발생하면서 냉각영역 전체에 고르게 분포하는 유동을 형성하고 냉각 성능이 개선되는 원인을 확인할 수 있었다.

• Current Photovoltaic Research
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• 제10권2호
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• pp.56-61
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• 2022

Recently, the expansion of the domestic solar market due to the promotion of eco-friendly and alternative energy-related policies is promising, and it is expected to lead the high-efficiency/high-power module market based on M10 or larger cells to reduce LCOE, 540-560W, M12 based on M10 cells Compared to the existing technology with an output of 650-700W based on cells, it is necessary to secure competitiveness through the development of modules with 600W based on M10 cells and 750W based on M12 cells. For the development of high efficiency/high-power n-type bifacial, it is necessary to secure a lightweight technology and structure due to the increase in weight of the glass to glass module according to the large area of the module. Since the mechanical strength characteristics according to the large area and high weight of the module are very important, design values such as a frame of a new structure that can withstand the mechanical load of the Mechanical Load Test and the location of the mounting hole are required. In this study, a structural analysis design model was introduced to secure mechanical reliability according to the enlargement of the module area, and the design model was verified through the mechanical load test of the actual product. It can be used as a design model to secure the mechanical reliability required for PV modules by variables such as module area, frame shape, and the location and quantity of mounting holes of the structural analysis model verified. A relationship of output drop can be obtained.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.98.5-98
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• 2002

1. Introduction 2. System Overview 3. Tracking and Auto Zooming algorithm 3.2 Automatic ROI Setting 3.3 Escaping of the local distracters 4. Pan/Tilt Control System, Performance Evaluation 5. Conclusion

• 한국동물학회:학술대회논문집
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.220.2-220
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• 2003

No Abstract, See Full Text

• International Journal of Internet, Broadcasting and Communication
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• 제12권1호
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• pp.7-13
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• 2020

We describes V2X technology, a connectivity-based recognition technology that is attracting attention as a key technology for implementing autonomous driving technology, and autonomous communication modules that implement ADAS technology, a sensor-based recognition technology. It also explains the trends in V2X technology standardization centered on IEEE 802.11p, which is a WAVE technology standard based on Wi-Fi/DSRC. Finally, we will discuss the market growth trend of V2X communication modules in the United States, the leading V2X technology module, and the development of technology development trends of major domestic and international companies that are leading the global technology market related to V2X communication modules. V2X and ADAS technologies will be the biggest influence on automotive purchasing decisions. In recent years, V2I mandates have been promoted beyond V2V, mainly in developed countries such as the United States. The related industry needs to focus on the development of information transmission network technology that can support high frequency high efficiency(transmission rate) and sophisticated positioning accuracy beyond conventional vehicle communication.