• Title/Summary/Keyword: 조우식

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A study on the Correlation Hazard Analysis for Signaling System Safety (안전성 확보를 위한 위험원 분석 기법간 상관관계에 대한 연구)

  • Han, Chan-Hee;Lee, Young-Soo;Ahn, Jin;Jo, Woo-Sic
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.638-645
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    • 2007
  • Computers are increasingly being introduced into safety and reliability critical systems. The safe and reliable operation of these systems cannot be taken for granted. Malfunctions of these systems can have potentially catastrophic consequences and they have already been involved in serious accidents. Software fault prevention, fault tolerance, fault removal and fault forecasting are the techniques to be used, implemented and verified for embedded software in critical systems as the contributors to safety and reliability of the software. To use them when developing a software product, a relationship must be established between them and the development processes, the methods and techniques to be used to develop software, as well as with the different product architectures. Railroad signaling system software is a safety-critical embedded software with realtime and high reliability requirements. The primary purpose of the safety management is to prevent the loss of lives or physical damages arising from potential hazards in the railroad signaling system. This study provides a systematic approach to analysis of potential hazards for their management during the system life cycle to assure the identification and definition of the most appropriate hazards.

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Changes of Fatty Acid Composition by Various Developmental Stage and Fruit Body Section in Pleurotus ostreatus (느타리버섯 자실체의 부위 및 생육시기별 지방산 조성의 변화)

  • Rew, Young-Hyun;Lee, Sook-Hee;Jo, Woo-Sik;Yoon, Jae-Tak
    • The Korean Journal of Mycology
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    • v.28 no.2
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    • pp.109-111
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    • 2000
  • Composition of fatty acids (FAs) in Pleurotus ostreatus were analyzed by gas chromatography and compositional changes according to cultivar, fruitbody section and developmental stage (days after primordia formation) were investigated. Major FAs in oyster mushroom were linoleic acid, oleic acid and palmitic acid. Unsaturated FAs were higher in pileus portion than upper- or lower-stipe portion. Oleic acid content was increased with developmental days but linoleic acid content was highest at $3{\sim}4$ days after primordia formation and then decreased after that. And ratio of unsaturated FAs/saturated FAs was decreased with basidiocarp maturation.

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Antioxidant and antitumor activities of ethanol extracts from the fruiting body of Phellinus gilvus grown in oak and artificial sawdust (참나무 원목 및 톱밥에서 재배된 마른진흙버섯 자실체의 에탄올 추출물에 대한 항산화 및 항암활성)

  • Hwang, Mi-hyun;Kim, Young-hoan;Kim, Kil-soo;Kim, Tae-wan;Jo, Woo-sik;Choi, Sung-guk;Kim, Jong-choon;Park, Seung-chun
    • Korean Journal of Veterinary Research
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    • v.45 no.2
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    • pp.151-154
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    • 2005
  • The purpose of this study is to examine the elemental compositions, antioxidant and antitumor activity of water, 20%, 40%, 60%, and 80% ethanol extracts obtained from the fruiting body of Phellinus gilvus. In electron donating ability test, the strong activities more than 70% were observed in $80{\mu}g/ml$ of 20%, 40%, 60% and 80% ethanol extracts from the fruiting body of P. gilvus grown in oak and sawdust. The antitumor activity was evaluated by sulforhodamine B (SRB) in terms of cell survival level. The tumor cells (sarcoma 180) were treated with various ethanol extracts (water, 20, 40, 60 and 80%). The results showed that all extracts inhibited proliferation showing a dose-dependent manner against tumor cells.

A New Soft-switched Half-bridge Converter with Low-voltage Rated Switch for 800V Battery EV LDC (800V 배터리 전기자동차 LDC용 낮은 스위치 전압정격을 갖는 새로운 소프트 스위칭 하프브리지 컨버터)

  • Kim, Byeongwoo;Kim, Kangsan;Cho, Woosik;Naradhipa, Adhistira M.;Kim, Kyuyeong;Choi, Sewan
    • Proceedings of the KIPE Conference
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    • 2018.07a
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    • pp.96-98
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    • 2018
  • 본 논문에서는 800V 배터리 전기자동차 LDC용 낮은 스위치 전압정격을 갖는 새로운 소프트 스위칭 하프브리지 컨버터를 제안한다. 제안하는 컨버터는 입력이 직렬구조로써 입력전압의 절반으로 낮은 스위치의 전압정격을 갖기 때문에 600V의 Si-MOSFET를 사용할 수 있어 도통손실을 줄일 수 있으며 부분공진 동작으로 스위칭 손실 저감 효과를 갖고, 넓은 입력전압 및 부하영역에서 소프트 스위칭을 성취하여 높은 효율을 달성할 수 있으며 변압기의 직렬연결로 된 커패시터로 인해 자화 전류의 오프셋이 없다. 제안하는 소프트 스위칭 컨버터의 동작원리를 제시하고 시작품을 통해 본 논문의 타당성을 검증하였다.

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Development of Cheap Substrate for Fruiting of Pleurotus ostreatus using Paper Sludge (제지 부산물을 이용한 느타리버섯(Pleurotus ostreatus) 자실체 형성용 염가배지개발)

  • Jo, Woo-Sik;Yun, Yeong-Seok;Park, Sun-Do;Choi, Boo-Sull
    • The Korean Journal of Mycology
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    • v.23 no.3 s.74
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    • pp.197-201
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    • 1995
  • For 2 years $(1993{\sim}1994)$, study on development of cheap medium for Pleurotus ostreatus revealed that paper sludge contain more CaO and similar T-C, T-N, $P_2O_5$, MgO but less $K_2O$ than any other medium material in chemical property. Mixed treatment (rice straw + paper sludge 10, 30, 50%, cotton waste + paper sludge 10, 30, 50%, cotton waste + rice hull 20 + paper sludge 10, 30, 50, 70%) is similar or fast a little in mycelial growth and is similar or fast $1{\sim}2$ day in period of primordia formation than cotton waste medium, and in the yield to each medium type also increased but excepted in rice hull 20% + paper sludge 70%, especially mixed medium at 7:3 ratio of cotton waste and paper sludge is best treatment because it is increased to 21%. In economical analysis, mixed medium at 7:3 ratio of cotton waste and paper sludge is increased to 50% compared to cotton waste medium in relative income.

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Experimental Study on Local Mass Transfer Characteristics of Flat Plate Using Tripping Wire (트리핑 와이어를 사용한 평판에서의 국소물질전달 특성에 관한 실험적 연구)

  • Yoo, Seong-Yeon;Cho, Woong-Sun;Jo, Woo-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.3
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    • pp.285-292
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    • 2013
  • The purpose of this research is to investigate how the boundary layer separation caused by a tripping wire installed in front of the flat plate affects the transition from laminar to turbulent flow, and consequently mass transfer. A naphthalene sublimation technique is used to measure the local mass transfer coefficients on the flat plate, and two boundary conditions for the developed and developing flow are considered to evaluate the effects of the flow boundary. The local mass transfer data for a flat plate with a tripping wire are compared with the data for a flat plate without a tripping wire. The variation trends of the local heat transfer coefficients for the plates with and without the tripping wire are similar to each other in the case of the developing flow, but are quite different for the developed flow. The average Sherwood number for the flat plate with a tripping wire is much higher than that without a tripping wire because of the boundary layer separation.

The difference of occurring pattern of Hericium erinaceus by pinheading induction methods (노루궁뎅이버섯(Hericium erinaceus) 봉지재배시 발이유도 처리방법에 따른 자실체 발생양상)

  • Kang, Min-Gu;Jo, Woo-Sik;Kim, Woo-Hyun;Choi, Seong-Yong;Park, So-Deuk
    • Journal of Mushroom
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    • v.13 no.1
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    • pp.11-15
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    • 2015
  • In recent years, Hericium erinaceus became famous for comsumer because it contains some materials to assist in human health. This study was carried out to find the difference of occurring pattern of H. erinaceus by pinheading induction methods. Harvest period of T1, T2 treatments were longer than T3~T6. All treatments fresh weights were not significantly different, but T3, T6 treatments's dry weight in 2nd flush were lower than others. T5 treatment's 2nd flush's regeneration rate was the highest than others and looks best quality. Therefore, it is suggested that pinheading induction method would be changed not T1, T2 treatment which were used some farm as Pluerotus ostreatus cultivation, but to scratch surface method which is T5 treatment for cultivation of high quality H. erinaceus.

Development of Fruitbody in the Artificial Oak Sawdust Cultures of Phellinus gilvus Mushroom (마른진흙버섯(Phellinus gilvus)의 톱밥재배 기술에 관한 연구)

  • Jo, Woo-Sik;Rew, Young-Hyun;Kim, Chang-Bae;Choi, Sung-Guk
    • The Korean Journal of Mycology
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    • v.30 no.2
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    • pp.109-112
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    • 2002
  • Present experiments were conducted to determine the possibility of artificial culture with oak sawdust block of Phellinus gilvus Mushrooms, Mycelial growth in sawdust block (oak 90 + rice bran 10, V/N) after 25 days. It took 12 days to make fruitbody from burying of sawdust block to pinhead formation. The fruitbodies produced the total fresh weight 577 g (dried weight 97 g) in a block.

Occurrence of Bluish Green Mold of Pleurotus eryngii by Penicillium corylophilum (Penicillium corylophilum에 의한 큰느타리버섯(Pleurotus eryngii) 푸른곰팡이병의 발생)

  • Jo, Woo-Sik;Rew, Young-Hyun;Kim, Sung-Han;Yun, Jae-Tak;Choi, Boo-Sull
    • The Korean Journal of Mycology
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    • v.27 no.6 s.93
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    • pp.412-414
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    • 1999
  • Bluish green mold of Pleurotus eryngii caused by Penicillium was observed in Seungju on Feburary 4, 1999. The causal fungus was identified as Penicillium corylophilum based on its cultural and morphplogical characteristics. Conidiophores one-stage branched, terminating in a whorl of $2{\sim}4$ metulae. Metulae mostly $10{\sim}18{\times}2.5{\sim}3.0\;{\mu}m$. Phialides flask-shaped, $9{\sim}13{\times}2.2{\sim}2.8\;{\mu}m$. Conidia subglobose, $2.5{\sim}3.2{\times}2.5{\sim}3.0\;{\mu}m$. Colonies on Czapek agar mostly attaining a diameter of 21 mm within 7 days at $25^{\circ}C$. Colour blue-green soon becoming grey-green. Pathogenicity test by wound inoculation revealed that Penicillium corylophilum caused the same symptoms as observed in the field at $6{\sim}7$ days after inoculation.

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Comparison of Mineral Contents and Antioxidant Activities of Domestic and Chinese Wolfiporia extensa for Origin Identification (국내산과 중국산 복령의 원산지 구별을 위한 성분 분석 및 항산화 활성)

  • Park, Na-Hye;Jo, Woo-Sik;Park, Seung-Chun
    • Journal of Mushroom
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    • v.14 no.4
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    • pp.232-236
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    • 2016
  • This study aimed to discriminate the geographical origins of domestic and chinese Wolfiporia extensa. They were subjected to oxygen (45.32 to 48.07%), carbon (38.09 to 40.12%), hydrogen (6.05 to 6.78%), and nitrogen (0.16 to 0.23%). Antioxidant activity was examined by DPPH free radical scavenging activity. According to the results of the experiment, no significant differences were found between domestic ($IC_{50}$, 7.25 mg/ml) and Chinese ($IC_{50}$, 8.35 mg/ml) W. extensa. However, as determined by the inorganic mineral contents were significantly different between domestic and Chinese W. extensa. The amount of potassium in domestic and Chinese W. extensa was and $33.14{\pm}17.27%$, $47.60{\pm}8.78%$, respectively. The results of this study suggested that the analysis of inorganic components by ED-XRF should be useful for origin identification of W. extensa.