http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
촉매물질을 이용한 수처리 기법의 결정화 화울링의 저감에 관한 연구
김선도(Sun Do Kim),박복춘(Bock Choon Pak),백병준(Byung Joon Baek),김철생(Cheol Sang Kim) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4
The present experimental study aimed to investigate the feasibility of physical water treatment (PWT) devices using catalytic materials to mitigation of crystalization fouling. Two PWT devices having different shape and material were used. The results from microscopic observation and SEM photographs demonstrate that the crystal structure of CaCO₃ is Argonite type without water treatment while Calcite type with water treatment, which clearly shows the feasibility of PWT techinque using catalytic materials to mitigate crystalization fouling. For 500 ppm solution, the fouling resistance decreased up to about 23% due to physical water treatment using catalytic materials. The results also reveal that if two more techniques are used simultaneously the additional effects could be expected.
이동네트워크에서 멀티캐스트 세션지연을 개선하기 위한 핸드오프 프로토콜
권상도,김경준,김철원,Kwon, Sang-Do,Kim, Kyung-Jun,Kim, Cheol-Won 한국정보통신학회 2010 한국정보통신학회논문지 Vol.14 No.6
무선 네트워크에서 멀티캐스트 세션 프로토콜은 호스트의 이동에 의해 발생하는 멀티 캐스트 프로토콜의 세션지연을 줄이며, MSDR의 핸드오프 스킴을 제안한다. MSDR 프로토콜은 세션 재설정에 의한 지연을 최소화 하면서, 이동 호스트의 멀티 캐스트 서비스를 지원하기 위해 IETF의 모바일 IP와 DFA의 유니 캐스트 라우팅 기능을 이용하며, 이동 호스트가 기본 셋을 통과할 때 지속적으로 패킷을 수신할 수 있다. 제안하는 프로토콜의 성능 평가를 위해 시뮬레이션을 수행했으며, 시뮬레이션 결과는 제안하는 MSDR 프로토콜은 시그널 비용 측면에서 개선된 멀티캐스트 전송 성능을 나타낸다. A multicast session protocol in wireless networks reduces the session delay of multicast delivery caused by moving of mobile host. A hand-off scheme, called MSDR (multicast session delay reduction), in mobile networks is proposed. MSDR protocol that minimizes the delay of a session re-establishment uses the basic unicast routing function of the IETF mobile IP and the DFA (designated foreign agent) to provide multicast services for mobile hosts. Proposed MSDR protocol allows the mobile hosts to continuously receive packets when they move across the basic sets during hand-off. Discrete-event simulation carried out for performance evaluation of MSDR protocol, and simulation results indicated that our scheme can offer a better performance of multicast session delay reduction in terms of signalling cost than that of IETF.
구속효과를 구려한 가스배관 결함의 2차원적 파괴거동 해석에 관한 연구
심도준,장영균,최재붕,김영진,김철만,Sim, Do-Jun,Jang, Yeong-Gyun,Choe, Jae-Bung,Kim, Yeong-Jin,Kim, Cheol-Man 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.1
EFP(Fitness For Purpose) type defect assessment methodologies based on ECA(Engineering Critical Analysis) have been established and are in use for the structural integrity evaluation of gas pipelines. ECA usually includes the fracture mechanics analysis, and it is assumed that the J-integral uniquely characterizes the crack-tip stress-strain field. However, it has been proven that the J-integral alone can not be sufficient to characterize the crack-tip field under low levels of constraint with a single parameter. Since pipeline structures are made of ductile material, locally loaded in tension, cracks may experience low level of constraint, and therefore, J-dominance will be lost. For this reason, the level of constraint must be quantified to establish a precise assessment procedure for pipeline defects. The objective of this paper is to investigate the fracture behavior of a crack in gas pipeline(KS D 3507) by quantifying the level of constraint. For this purpose, tensile tests and CTOD tests were performed at room temperature(24$\^{C}$) and low temperature(-40$\^{C}$) to obtain the material properties. J-Q analyses were performed for SENB and SENT specimens based on 2-D finite element analyses, in order to investigate the in-plane constraint effects on pipeline defects. For precise assessment of cracks, especially shallow cracks, in KS D 3507 pipeline, constraint effect must be considered.
한국 남해안 다도해·한려해상국립공원 도서의 해조상 및 군집구조 변화
오지철(Ji Chul Oh),김호연(Ho Yeon Kim),조현근(Hyun-Geun Cho),김철도(Cheol Do Kim),안중관(Jung Kwan Ahn) 국립공원연구원 2015 국립공원연구지 Vol.6 No.3
We investigated species composition and variation of benthic marine algae between 2014 at southern coast island, Korea. Coarsely branched form seaweeds were dominant functional group comprising 47.73% in species number, whereas filamentous form (18.64%), sheet form (11.82%), thick leathery form (9.55%), crustose form (6.82%), jointed calcareous form comprised 5.45%. C/P, R/P and (C+R)/P values were 0.33, 0.96 and 2.57, respectively. Such fast growing ESG II (ecological state group) was 22.65% and slow growing perennial algae, ESG I was only 77.35%. 본 연구는 14년 남해 연안 도서에서 조하대 해조류 종구성과 변화를 파악하기 위해 수행하였다. 연구기간 출현한 해조류는 총 220종(녹조 20종, 갈조 60종, 홍조 140종)이 출현하였다. 해조류의 기능형은 성긴분기형(47.73%), 사상형(18.64%), 엽상형(11.82%), 다육질형(9.55%), 각상형(6.82%), 유절산호말형(5.45%)으로 구분되었다. 해조상의 지역적 특성을 나타내는 C/P값은 0.33을 보였고, R/P값은 0.96, (R+C)/P값은 2.57로서 혼합형 해조상을 보였다. 또한, 환경상태와 밀접한 관련을 보이는 ESG II의 비율은 약 22.65%를 보여 해조상을 통해 파악된 국립공원 내 도서지역 환경상태는 양호한 편이다.
안중관(Jung-Kwan Ahn),정장방(Jang Bang Jeong),김철도(Cheol Do Kim) 국립공원연구원 2015 국립공원연구지 Vol.6 No.4
다도해해상국립공원 내 해초류 분포 및 개체군 특성을 조사하였다. 거머리말(Zostera marina)은 다물도, 흑산도 배낭기미, 도초도 시목, 관매도, 소안도, 거문도에서 분포하였고, 애기거머리말(Z. japonica)은 하조도 동구섬과 세목 그리고 외래 유입종으로 알려진 해호말(Halophila nipponica)은 거문도에 분포하였다. 거머리말 밀도는 거문도(333 ± 177 shoots/m2)에서 가장 높았으며, 흑산도 배낭기미(215 ± 29 shoots/m2)에서 낮았고, 하조도의 애기거머리말은평균 밀도 1,425 shoots/m2, 거문도의 해호말의 평균 밀도는 576 shoots/m2로 나타났다. 거머리말의 형태학적 특징은 조사정점에 따라 서로 상이하게 나타났다. This study was distribution characteristics of seagrasses at Dadohaehaesang National Park. Zostera marina was distributed in Damuldo, Beanangkimi, Simol, Gwanmado, Soando and Geomundo. Z. japonica was distributed in Hajodo (Donggusum and Seomok). Halophila nipponica was distributed in Geomundo. The most average density of Zostera marina were found at Geomundo (333 ± 177 shoots/m2), Soando (320 ± 86 shoots/m2), while the fewest were found at Beanangkimi (215 ± 29 shoots/m2). The most average biomass was 570 g DW/m2 at Gwanmaedo, fewest at Simok (167 g DW/m2). Morphological characteristics of Zostera marina were different depending on the region. The average density of Z. japonica was 1,425 shoots/m2 at Hajodo. The average density of Halophila nipponica was 576 shoots/m2 at Geomundo.
오지철 ( Ji Chul Oh ),최한길 ( Han Gil Choi ),김철도 ( Cheol Do Kim ),안중관 ( Jung Kwan Ahn ) 한국수산과학회(구 한국수산학회) 2016 한국수산과학회지 Vol.49 No.3
Seasonal variability in the algal community structure of intertidal zones was examined at six study sites in Marine National Parks, on the western and southern coasts of Korea from March to November 2015. A total of 193 species of algae, comprising 27 green, 40 brown and 126 red algae, were identified. Algal biomass averaged 101.50 g dry wt./㎡ with a maximal at Tonggae (168.12 g dry wt./㎡) and minimum at Haseom (54.49 g dry wt./㎡). The dominant seaweeds by biomass were Sargassum thunbergii at five sites (Tonggae, Haseom, Namdongri, Ando amd Sinjeonri), and S. fusiforme at Soando. Community indices measured as follows: dominance index (DI), 0.31-0.69; richness index (R), 7.30-11.43; evenness index (J`), 0.33-0.49; and diversity index (H`), 1.15-1.86. As evaluated using community indices and environmental states, the EEI (Ecological Evaluation Index) of the Marine National Park was "normal". The present results indicate that seaweed community structures and indices could be used to evaluate the environmental status of coastal ecosystems.
[단보] 해상·해안국립공원의 해양생물 다양성 현황과 확보방안
이창래(Chang-rae Lee),이상규(Sang-kyu Lee),서승직(Seung Jik Suh),김철도(Cheol Do Kim) 국립공원연구원 2015 국립공원연구지 Vol.6 No.3
지구상에 분포하는 생물종수는 약 175만종으로 알려져 있지만, 해양생물에 대한 분류학적 연구가 계속 진행된다면 생물종은 약 500만에서 3,000만종이 이를 것으로 예상하고 있다. 우리나라 주변 해역에 분포하는 해양생물의 총 종수는 약 9,534종으로 추정되며, 이중 해상·해안국립공원에서 확인된 해양생물 종수는 2,437종으로 이는 우리나라 전체 해양생물중 약 26%에 해당되었다. 국립생물자원관 등 유관기관과의 공동연구들 통해 공원 내 해양생물다양성은 크게 증가할 것으로 예상된다. Species richness of distribution on the earth is known as about 175 million species, but if the classification research of marine life studies consistently, Number of species was expected about five million to 30 million species. The total number of species of marine life to be distributed around sea of Korea are estimated to be about 9,534 species, and the number of marine species in Haesang·Haean National Park has been identified 2,437. Through joint research with related agencies such as the National institute of biological resources, marine biodiversity in the park is expected to increase significantly.