• Title/Summary/Keyword: Open Cycle

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

  • Choi, In Young;Kang, Young June;Hong, Kyung Min;Kim, Seong Jong;Lee, Hae Gyu
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.4
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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.

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

  • Choe, Sanki
    • Korean Institute of Interior Design Journal
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    • v.23 no.1
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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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    • v.11 no.6
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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.

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

  • Hwang, Changhwan;Lee, Kwangjin;Woo, Seongphil;Im, Ji-Hyuk;Jeon, Junsu;Lee, Jungho;Yoo, Byungil;Han, Yeoungmin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.88-93
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    • 2017
  • For the control of pre-burner combustion pressure, the open angle of TTR(Throttle for Thrust Regulation) valve was varied from $143^{\circ}$ to $185^{\circ}$ while testing of cold flow, ignition, combustion. The major performance variables of rocket engine and hydraulic performance of TTR valve regarding the open angle was verified. However the controllability of pre-burner combustion pressure was not verified due to the limitations of test. The comprehensive research will be done after supplementing these problems.

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

  • Jun, So-Young;Hwang, Seon-Hwan;Park, Jong-Won
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.6_2
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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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    • v.55 no.7
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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.

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

  • Baek, Seungdong;Sung, Taehong;Lee, Minseok;Kim, Kyung Chun
    • Journal of the Korean Institute of Gas
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    • v.20 no.5
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    • pp.50-56
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    • 2016
  • In this work, the open-drive oil free air compressor is modified to activate an organic Rankine cycle system as an expanding machine. The shape of the modified scroll expander case is a rectangular parallelepiped and the size of the case is $0.0394m^3$. The scroll expander is operated in an ORC using R245fa as working fluid with various working conditions for the performance test. The test data points are used to calculate the parameters of the scroll expander semi-empirical simulation model. The simulation results are compared with the experimental results to validate the simulation model.

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

  • Yoo, Han-Na;Yoo, Jung-Ki;Choi, Seoung-Jun;Kim, Jin-Kyeoung
    • Reproductive and Developmental Biology
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    • v.34 no.3
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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.

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

  • Yun, Eunkoo;Kim, Hyun Dong;Yoon, Sang Youl;Kim, Kyung Chun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.10
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    • pp.919-926
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    • 2013
  • Experiments were conducted to determine the operating characteristics of a small-scale ORC (organic Rankine cycle) system for various low-temperature heat sources. A small-scale ORC power generation system adopting R-245fa as a working fluid was designed and manufactured. Hot water was used as the heat source, and the temperature was controlled using 110-kW electric resistance heaters that provided temperatures of up to $150^{\circ}C$. An open-drive oil-free scroll expander directly connected to a synchronous generator was installed in the ORC unit. Experiments were conducted by varying the rotational speed of the expander under the same heat source temperature conditions. The factors that influence the performance of the small-scale ORC system were analyzed and discussed.

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

  • 이기숙
    • Journal of Families and Better Life
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    • v.6 no.1
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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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