• 제목/요약/키워드: Open cycle

검색결과 401건 처리시간 0.024초

스마트 폰과 이미지 상관법을 이용한 무선 원격 계측 알고리즘 개발 (Development of a Wireless Telemetry Measurement Algorithm Using Smart Phones and Digital Image Correlation)

  • 최인영;강영준;홍경민;김성종;이해규
    • 한국생산제조학회지
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    • 제24권4호
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    • pp.434-440
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    • 2015
  • A smart phone is a multimedia device that is a necessity for modern people. It includes a wireless networking system to share information and pictures. However, numerous smart phones are discarded every year, since they have a very fast technology development cycle. This paper presents the development of a telemetry algorithm to measure displacement and strain with a discarded smart phone and digital image correlation methods. To implement the measurement algorithm, the LabVIEW 2010 program development platform was used. In order to verify reliability, an open hole tension test was conducted using a smart phone and a universal test machine. In addition, the measurement results from the smart phone were compared with FEM analysis results.

근대 건축의 가치를 반영한 리노베이션과 보존에 관한 연구 - 국내 1960-70년대 모더니즘 건축의 리노베이션에 관한 연구 - (Renovation and Conservation based on the Significance of Modern Architecture - A Study on Renovation of Korean Modern Architecture of 1960-70s -)

  • 최상기
    • 한국실내디자인학회논문집
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    • 제23권1호
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    • pp.34-42
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    • 2014
  • The early post-war modern architecture introduced to Korea in the 60's and 70's have reached its 50 year cycle to emerge as candidates for the registered heritage. However, conservation is a complicated topic when applied to modern architecture due to its social and political status among general public, and is often a sacrificial target for demolition or insensitive alteration. This research tries to identify significant values extracted from the intrinsic characteristics of modern architecture, that can be applied to conducting successful renovation projects on modern architecture. The conservational values of modern architecture to be maintained are identified in this paper as: flexible open space, material and structural system, and extension of interior-exterior relation. These values are examined through the filter of comparative analysis on domestic and international conservation standards, along with cross-examination on recently renovated local works performed on the modern architecture of the period. This research aims to bring focus on conducting respectful conservation and renovation to modern architecture by identifying the significant values that is intrinsic to the modern architecture and is worth preserving.

An Open Circuit Fault Diagnostic Technique in IGBTs for AC to DC Converters Applied in Microgrid Applications

  • Khomfoi, Surin;Sae-Kok, Warachart;Ngamroo, Issarachai
    • Journal of Power Electronics
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    • 제11권6호
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    • pp.801-810
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    • 2011
  • An open circuit fault diagnostic method in IGBTs for the ac to dc converters used in microgrid applications is developed in this paper. An ac to dc converter is a key technology for microgrids in order to interface both distributed generation (DG) and renewable energy resources (RES). Also, highly reliable ac to dc converters are necessary to keep converters in continuous operation as long as possible during power switch fault conditions. Therefore, the proposed fault diagnostic method is developed to reduce the fault detection time and to avoid any other fault alarms because continuous operation is desired. The proposed diagnostic method is a combination of the absolute normalized dc current technique and the false alarm suppression algorithm to overcome the long fault detection time and fault alarm problems. The simulation and experimental results show that the developed fault diagnostic method can perform fault detection within about one cycle. The results illustrate that the reliability of an ac to dc converter interfaced with a microgrid can be improved by using the proposed fault diagnostic method.

다단연소사이클 액체 로켓엔진의 압력제어에 대한 연구 (Pressure Control of Staged Combustion Liquid Rocket Engine)

  • 황창환;이광진;우성필;임지혁;전준수;이정호;유병일;한영민
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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    • pp.88-93
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    • 2017
  • 나로우주센터에 구축/개발된 3단 엔진 연소시험설비에서 다단연소사이클 액체 로켓엔진의 시험을 수행하였다. 수류시험과 점화시험, 연소시험이 이루어졌으며 예연소기의 연소압력 제어를 위한 TTR의 개도를 $143^{\circ}$에서 $185^{\circ}$ 까지 변화시키며 시험을 수행하였다. 시험 결과 엔진의 주요성능과 TTR 개도에 의한 수력학적 변화를 확인하였지만 연소압력의 제어성 확인을 위한 결과는 얻지 못하였다. 향후 본 논문의 연구에서 도출된 개선점을 보완한 예연소기 압력제어 연구가 이루어질 것이다.

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비대칭 6상 영구자석 동기 전동기의 스위치 개방에 따른 특성 분석 및 고장허용운전 (Fault Tolerance Operation and Characteristics Analysis of Asymmetric Six-phase Permanent Magnet Synchronous Motor According to Switch Open)

  • 전소영;황선환;박종원
    • 한국산업융합학회 논문집
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    • 제25권6_2호
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    • pp.1003-1008
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    • 2022
  • This paper proposes a method related to fault tolerance operation and characteristic analysis of asymmetric 6-phase permanent magnet synchronous motor. In general, motor drive systems with multi-phase structures can be continuously operated despite a reduction of power and speed by using a phase changeover or control techniques according to the failures. As a result, it is widely used in industrial fields such as aviation and defense, which require high efficiency and high reliability. In this paper, the second order ripple of the electrical fundamental freuqnecy occurs in the dq-axis currents of the synchronous coordinate system through mathematical analysis according to the switch open of the dual 3-phase inverter. Therefore, the fault tolerant operation method is presented by applying the fault detection method with a constant cycle for continuous operations. The effectiveness of the proposed fault tolerance operation method is verified through the several experiments.

Modelling of the fire impact on CONSTOR RBMK-1500 cask thermal behavior in the open interim storage site

  • Robertas Poskas;Kestutis Rackaitis;Povilas Poskas;Hussam Jouhara
    • Nuclear Engineering and Technology
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    • 제55권7호
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    • pp.2604-2612
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    • 2023
  • Spent nuclear fuel and long-lived radioactive waste must be carefully handled before disposing them off to a geological repository. After the pre-storage period in water pools, spent nuclear fuel is stored in casks, which are widely used for interim storage. Interim storage in casks is very important part in the whole cycle of nuclear energy generation. This paper presents the results of the numerical study that was performed to evaluate the thermal behavior of a metal-concrete CONSTOR RBMK-1500 cask loaded with spent nuclear fuel and placed in an open type interim storage facility which is under fire conditions (steady-state, fire, post-fire). The modelling was performed using the ANSYS Fluent code. Also, a local sensitivity analysis of thermal parameters on temperature variation was performed. The analysis demonstrated that the maximum increase in the fuel load temperatures is about 10 ℃ and 8 ℃ for 30 min 800 ℃ and 60 min 600 ℃ fires respectively. Therefore, during the fire and the post-fire periods, the fuel load temperatures did not exceed the 300 ℃ limiting temperature set for an RBMK SNF cladding for long-term storage. This ensures that fire accident does not cause overheating of fuel rods in a cask.

유기랭킨사이클용 소형 스크롤 팽창기 제작 및 성능 특성 연구 (Fabrication and Study on the Performance Characteristics of a Scroll Expander for Organic Rankine Cycle)

  • 백승동;성태홍;이민석;김경천
    • 한국가스학회지
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    • 제20권5호
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    • pp.50-56
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    • 2016
  • 본 연구에서는 개방형 무급유식 스크롤 압축기를 개조하여 유기랭킨사이클(ORC)용 소형의 스크롤 팽창기를 설계 및 제작하였다. 팽창기 케이스는 직육면체 형태로 총 체적은 $0.0394m^3$이며, 성능특성 연구를 위해 작동유체로 R245fa를 사용하는 ORC 사이클을 구축하고, 다양한 팽창기 입구압력 및 회전속도 조건에서 성능시험을 수행하였다. 성능시험에서 획득한 열역학적 물성값을 스크롤 팽창기의 semi-empirical 시뮬레이션 모델에 적용해 파라미터를 계산하고, 열역학적 분석을 통해 계산한 실험값과 시뮬레이션값의 비교를 수행하였다.

인간 배아 줄기세포와 암 세포에서의 C6orf62의 발현 패턴 (Expression of C6orf62 in Human Embryonic Stem Cells and Cancer Cells)

  • 유한나;류중기;최성준;김진경
    • Reproductive and Developmental Biology
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    • 제34권3호
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    • pp.229-233
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    • 2010
  • Pluripotency and self-renewal capacity of human embryonic stem cells (hESCs) are retained by hESCs related genes as OCT4, SOX2 and NANOG. These genes are shown high expression level in diverse cancer cells and have potential role in the carcinogenesis. On the contrary to this, several genes which are up-regulated in the differentiated hESCs are involved to suppress the carcinogenesis or proliferation of cells. We discovered several genes in immortalized lung fibroblast (WI-38 VA13) by suppression subtractive hybridization. Among them, we focused chromosome 6 open reading frame 62 (C6orf62) which is uncharacterized, mapped to 6p22.3 and generated to Hepatitis B virus X-transactivated proteins (HBVx-transactivated proteins, XTP). Aim of this study was to characterize C6orf62 through analyzing of expression pattern in various cell lines. Expression of C6orf62 was significantly upregulated in diverse normal cell lines than cancer cell lines. And C6orf62 was up-regulated in differentiated hESCs (endothelial cells, neural cells) compared to those of undifferentiated hESCs. Also, C6orf62 in WI-38 cells was highly up-regulated during G1/S transition of the cell cycle. Taken together, C6orf62 is shown expression pattern similar to differentiated hESCs-associated genes which down-regulated in cancer cells. Therefore, we assume that C6orf62 may participate to suppress the proliferation and to induce differentiation through regulating the cell cycle.

소형 유기랭킨사이클 시스템 개발 및 작동특성에 관한 연구 (Development of Small-scale Organic Rankine Cycle System and Study on its Operating Characteristics)

  • 윤은구;김현동;윤상열;김경천
    • 대한기계학회논문집B
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    • 제37권10호
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    • pp.919-926
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    • 2013
  • 본 연구에서는 소형 저온 유기랭킨사이클 시스템의 작동특성을 파악하기 위하여 R-245fa를 작동유체로 사용한 소형 ORC 발전 시스템을 설계 및 제작하였고, 다양한 저온의 열원온도에 대한 실험적 연구를 수행하였다. 저온 열원을 모사하기 위하여 최고 $150^{\circ}C$의 물을 공급할 수 있는 110 kW급의 전기저항 히터를 제작하였으며, 컨트롤러를 통해서 다양한 열원 온도 및 유량조건에 대한 실험이 가능하도록 구성하였다. 또한, 상용 공기용 스크롤 압축기를 이용하여 팽창기로 개조하고 동력계 및 동기식 모터와 직접 연결하였다. 로드뱅크 및 PI 제어방식을 사용하여 팽창기의 회전속도에 따른 동일 열원온도 조건에 대한 실험을 각각 수행하였으며, 소형 ORC 시스템의 성능에 영향을 미치는 다양한 인자들에 대하여 분석하고 논의하였다.

가족주기에 따른 부부간 커뮤니케이션 변화에 관한 연구 (The Changes on Marital Communication over the family Life Cycle)

  • 이기숙
    • 가정과삶의질연구
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    • 제6권1호
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    • pp.167-187
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    • 1988
  • The purpose of this study is to explore whether wives communicate differently over the family life cycle(FLC), and whether their communication contents and frequencies are differently over the FLC. Marital communication scales are composed of six subfactors such as The selectivity of channel (SC), Channel direction (CD), communication style(CS), Comprehension of nonverbal communication (CNC), Communication contents and frequencies(CCF) and Olson's marital communication (LCQ). The number of the subjects are 582, who are living in Pusan in 1987 and they divided into six stages family life cycle; The newly married (FLC 1). The family with preschoolers(FLC 2), The family with schoolages (FLC3), The family with teenages(FLC4), The family with launching children(FLC 5) and The postparenthood (FLC 6). This study is surveyed by Frequencies and Mean score from six subfactors and tested by chi-square test and ANOVA. the results are as follows; 1) There are a few significant differences in CS and CNC by FLC. The wives from FLC 1 and FLC 2 use the most open communication style and them form FLC5 use the most closed style. There are revealed that comprehension of nonverbal communication is the highest of FLC2, but on FLC 1 it is the lowest. 2) There are significant difference in CCF. Children, Wive's life, Husband's life, Affection and sex and Empathy show significant differences over the over the FLC. Regardless of FLC, there are conclueded that Children, Wive's and husband's life and economy management are the most frequence communicative contents. These results suggest that there needs to be further investigation on Olson's marital communication scale for comparing another country with ours and on the training and programs for couple's skillful communication ability.

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