• Title/Summary/Keyword: Po Kim

Search Result 1,718, Processing Time 0.061 seconds

Inhibitory Effect of Chlorine Dioxide on Phenoloxidase Activation of the Indianmeal Moth, Plodia interpunctella (화랑곡나방(Plodia interpunctella)의 페놀옥시데이즈 활성화에 대한 이산화염소의 억제 효과)

  • Kim, Minhyun;Kwon, Hyeok;Kim, Wook;Kim, Yonggyun
    • The Korean Journal of Pesticide Science
    • /
    • v.20 no.2
    • /
    • pp.138-144
    • /
    • 2016
  • Phenoloxidase (PO) is an oxidizing enzyme and plays crucial roles in insect immunity and cuticle sclerotization. High oxidizing activity of chlorine dioxide gives effective control activities against microbes and insect pests. These allowed us to assess any inhibitory activity of chlorine dioxide against PO with respect to insect immunity. PO activities of the Indeanmeal moth, Plodia interpunctella, was detected in both hemocytes and plasma. Upon bacterial challenge, PO activity was significantly increased especially in plasma. However, the immune challenge coupled with chlorine dioxide treatment did not enhance PO activity. When different chlorine dioxide concentrations were incubated with activated PO by immune challenge, they did not inhibit the activated PO. These results indicate that chlorine dioxide suppresses PO activity by inhibiting PO activation.

The Tense-Lax Question and Intraoral Air Pressure in English Stops

  • Kim, Dae-Won
    • Speech Sciences
    • /
    • v.9 no.4
    • /
    • pp.113-130
    • /
    • 2002
  • Measurements were made of pressure rise time (PoRT), voice cessation time, flattened peak intraoral air pressure (Po), pressure static time (PoST), pressure-fall time and the duration of oral closure as four English speakers uttered isolated nonsense $V_{1}CV_{2}$ words containing /b/ and /p/ ($V_{1}=V_{2}$ and the V was /$\alpha$/), with stress on either $V_{1}orV_{2}$ alternately. The hypothesis tested was: The tense stop consonant. will be characterized either by a higher Po or a longer PoST, and/or by both against lax. Findings: (1) PoRT was significantly greater in /b/ than /p/, (2) the voiceless stop /p/ produced generally greater mean Po, averaged across five tokens, than its voiced counterpart /b/, but statistically insignificant, and (3) altogether, across stress, tokens and subjects, the difference in the calculated pressure static time (PoSTc), i.e., PoST + PoRT, between /p/ and /b/ was highly significant (p $\leq$ 0.003). Although further investigations remain to be taken, the results strongly supported the linguistic hypothesis of tense-lax distinction, with /b/ being lax and /p/ tense. Airflow resistance at the glottis and supraglottal air volume are assumed to be responsible for much of difference in PoRT between /p/ and /b/. The PoSTc reflecting, although indirectly, the respiratory efforts during the oral closure of a stop, was a convincing phonetic parameter of the consonantal tenseness based on respiratory efforts. The effects of stress on Po and PoSTc were inconsistent, and the shorter PoRT than consonantal constriction interval was always accompanied by Po and PoST.

  • PDF

신규 참여자의 형평성 향상을 위한 블록체인에서의 새로운 증명 방식 연구: Proof-of-Probability

  • Kim, Sungmin;Kim, Kyeong Seon;Kim, Joongheon
    • Review of KIISC
    • /
    • v.28 no.3
    • /
    • pp.18-25
    • /
    • 2018
  • 최근 블록체인 기술을 응용한 가상화폐에 대한 관심이 높아지면서 자본금이 많지 않은 사람들도 블록체인 네트워크에 참여하기 시작했다. 가장 유명한 가상화폐인 비트코인이 채택한 PoW 방식은 고성능 하드웨어의 과열된 열풍을 불어왔고 PoS 방식은 기존 지분이 많은 참여자들이 많이 존재하여 소수의 자본금을 가진 신규 참여자들이 네트워크에 새로 참여하기 어려운 환경이다. 따라서 본 논문에서는 기존 블록체인 증명방식인 PoW, PoS 방식보다 네트워크 참여를 위한 자본금이 적고 신규로 참여하더라도 리스크가 적은 PoP(Proof-of-Probability) 방식을 소개한다. PoP 방식은 블록을 생성할 시 실제 암호화된 해쉬와 수많은 가짜 해쉬를 각 노드들이 정렬하여 진짜 해쉬를 복호화하여 찾은 노드가 블록을 생성하는 방식이다. 또한 1개의 해쉬를 복호화하여 검증받을 때 1분의 대기시간을 두어 과열된 컴퓨팅파워 경쟁을 제한한다. 지분(Stake)이 많을수록 블록을 생성할 확률은 높아지지만 이는 PoS 방식처럼 절대적이지 않다. 이 방식을 이용한다면 지분을 많이 가진 유효성 검증자(Validators)에 의한 집중화를 피하며 블록체인 네트워크에 참여하려는 진입장벽도 낮출 수 있을 것 이다.

Conceptual Design of 2MW Wind Turbine Generator with Low-speed Gearbox (저속 기어형 2MW급 풍력발전기 개념설계)

  • Sohn, Young-Uk;Kim, Young-Chan;Kim, Young-Whan;Lee, Eung-Chae;Park, In-Soo;Chung, Chin-Wha;Han, Kyung-Suep;Chun, Chung-Whan
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2006.06a
    • /
    • pp.319-322
    • /
    • 2006
  • Under the national project for the development of 2MW wind energy convert system, we are under development of the prototype of 2MW wind turbine with low speed gearbox. This system adopts low speed gear box with planetary and spur gear and is pitch regulated variable speed type with the synchronous permanent magnet generator. The compromised size of generator in diameter and width are adopted to meet the structural design requirements. In this paper, the concept study for the type, the aerodynamic design for the blade and the details of load calculation will be presented. The detailed characteristics of the system will also be introduced.

  • PDF

Performance and Emission Studies in a DI Diesel Engine Fuelled with Diesel-Pyrolysis Oil Emulsion (디젤-열분해유 유상액을 사용하는 직접분사식 디젤 엔진의 엔진성능 및 배기특성에 관한 연구)

  • Lee, Seokhwan;Kim, Hoseung;Kim, Taeyoung;Woo, Sejong;Kang, Kernyong
    • Journal of ILASS-Korea
    • /
    • v.19 no.2
    • /
    • pp.55-63
    • /
    • 2014
  • Pyrolysis oil (PO), also known as Bio crude oil (BCO), has the potential to displace significant amounts of fuels that are currently derived from petroleum sources. PO has been regarded as an alternative fuel for petroleum fuels to be used in diesel engine. However, the use of PO in a diesel engine requires modifications due to low energy density, high water contents, low acidity, and high viscosity of the PO. One of the easiest way to adopt PO to diesel engine without modifications is emulsification of PO with the fuels that has higher cetane number. However, PO that has high amount of polar chemicals is immiscible with non polar hydrocarbons of diesel. Thus, to stabilize a homogeneous phase of diesel-PO blends, a proper surfactant should be used. In this study, a DI diesel engine operated with diesel and diesel-PO emulsions was experimentally investigated. Performance and gaseous & particle emission characteristics of a diesel engine fuelled by diesel-PO emulsions were examined. Results showed that stable engine operation was possible with the emulsions and engine output power was comparable to diesel operation.

A Study on Key Management Technology for DRM (DRM에서 키 관리 기술에 관한 연구)

  • Yang, Seong-Hoon;Han, Dea-Yul;Kim, Seong-Hoon;Park, Ik-Su;Lee, Kyoung-Hyo;Jung, Seok-Won;Seo, Jae-Hyun;Kim, Jong-Hwa;Oh, Byeong-Kyun
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2005.05a
    • /
    • pp.1177-1180
    • /
    • 2005
  • DRM에서 키 관리 기술은 중앙 집중 키 관리 방식, Enveloping 방식 등이 있다. 본 논문에서는 암호화 키를 콘텐츠에 함께 동봉하는 키 관리 방식을 기반으로 새로운 DRM 키 관리 기술을 제안한다. 제안하는 키 관리 기술은 사용자 인증에서 사용된 인증정보를 콘텐츠 암호화 키로 사용함으로 콘텐츠 암호화 키를 암호화하여 전송할 필요가 없는 장점이 있다.

  • PDF

Relationships between pH, $NO_3{^-}$ and $PO{_4}^{3-}$ and phytoplankton distribution in the upper stream of Dorim-cheon (도림천 상류의 pH, $NO_3{^-}$, $PO{_4}^{3-}$와 식물성 플랑크톤 분포와의 관계)

  • Kim, Jae Geun;Kim, Taehyeon;Yoo, Jimin;Lee, Juyeon
    • Journal of Wetlands Research
    • /
    • v.14 no.2
    • /
    • pp.255-263
    • /
    • 2012
  • The stream has various environments and they are serving as main habitats of aquatic organisms. The distribution of phytoplankton is affected by water environment, especially pH, nitrogen and phosphorus. To reveal the relationship between phytoplankton distribution and water environment, we measured pH, $NO_3{^-}$ and $PO{_4}^{3-}$ concentration, and abundance of phytoplankton at 10 sites in the upper stream of Dorim-cheon. pH value ranged 5.05 to 7.56. $NO_3{^-}$ and $PO{_4}^{3-}$ concentrations ranged 0.4 ~ 4.9ppm and 0.02 ~ 0.99ppm, respectively. A point source of $NO_3{^-}$ was Seoul National University but concentration was not high and dropped to normal range at 400m downstream. $NO_3{^-}/PO{_4}^{3-}$ ratio ranged 28 to 152 except site 4 (0.4) where was affected by $PO{_4}^{3-}$ point source. Water pH, $NO_3{^-}$ and $PO{_4}^{3-}$ concentrations increased with downstream and were related to the input of irrigation water from Han-river between site 5 and 6. Bacillariophyceae alge dominated this stream. Phytoplankton density increased abruptly at downstream of site 5. In general, phytoplankton density did not increase until the $NO_3{^-}$ concentration of 3.5ppm and $PO{_4}^{3-}$ concentration of 0.07ppm. Phytoplankton density was low at sites where $NO_3{^-}/PO{_4}^{3-}$ ratio was larger than 50.

Design of 2MW Permanent Magnet Synchronous Generator (2MW 풍력발전기용 영구자석형 동기발전기 설계)

  • Suh, Hyung-Suck;Han, Hong-Sik;Jung, Young-Gyu;Lee, Hong-Gi;Lee, Wol-Woo;Kim, Dong-Eon;Chung, Chin-Wha;Chun, Chung-Hwan;Han, Kyung-Seop
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.1230-1231
    • /
    • 2007
  • 2MW 풍력발전기용으로 사용할 영구자석형 동기발전기 물리설계 과정을 설명하다. 기어비가 72.28인 3단 기어를 사용하여 영구자석 pole을 회전자 표면에서 3 mm 깊이로 삽입시켜 안정된 구조를 취했다. 토크, 인덕턴스, 유기전압, 손실, 온도분포 등을 계산하기 위해 전자기해석과 열해석 등을 통해 영구자석, 회전자, 고정자 등의 구조를 정하고와 크기를 최적화시켰다.

  • PDF