• 대한기계학회논문집B
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• 제37권2호
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• pp.171-179
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• 2013

선박의 주 추진용 디젤엔진으로부터 배출되는 배기가스의 열을 회수하는 폐열회수 발전시스템에 대하여, 상대적으로 고온에 상부의 3 변 사이클과 상대적으로 저온부에 하부의 유기 랭킨 사이클이 적용되는 복합 사이클에 대한 열역학적 특성을 조사하였다. 그 결과, 상부와 하부 사이클 사이에 경계온도의 증가에 따라, 총 파괴된 엑서지율(${\sum}\dot{E}_d$) 및 엑서지 손실율($\dot{E}_{out2}$)이 각각 감소되었기 때문에, 시스템의 에너지 및 엑서지 효율이 모두 최대화되었다. 그리고 상부의 체적 팽창비가 크게 감소되었다. 그 경우에 대하여, 부가적인 추진동력으로써 활용되는 폐열회수 발전시스템이 적용된 선박용 디젤엔진의 경우에, 추진 효율은 엔진부하 변동에 따라 기본 엔진에 대비하여 평균적으로 9.17 %가 향상되었다. 이에 대하여, 디젤엔진의 연료 소비율과 이산화탄소 배출률은 각각 평균 8.4 및 8.37 %가 저감되었다.

• Ocean and Polar Research
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• 제29권3호
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• pp.245-262
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• 2007

On 25 December 2000, China and Vietnam signed the Agreement on the Delimitation of the Territorial Seas, EEZs and Continental Shelves in the Tonkin Gulf. Three and a half years after signature, in June 2004, China and Vietnam both ratified a maritime boundary agreement for the Tonkin Gulf (Beibu Gulf) and the agreement entered into force. A potentially complicating factor in the negotiation process was likely to have been the status of the Sino-French Agreement of 1887. In the end, the agreement reached indicated that even if the status of the Sino-French Agreement of 1887 was part of the negotiations, both sides eventually agreed that it would not have an impact on the delimitation of maritime zones in the Gulf of Tonkin. Another crucial issue was the impact of the islands, in particular, the Vietnamese controlled Bach Long Vi Island and Con Co Island. Especially, Bach Long Vi Island was entitled to a half suite of maritime zones (3n.m. EEZ) and would impact the tracing of a line of equidistance in the Gulf of Tonkin. Minor as the point might be, Con Co Island also would have an impact for it would play a fixing terminal point for the boundary. Article 7 of the agreement is about minerals and hydrocarbons of cross-boundary deposit, and if any single geophysical structure of oil and gas or other mineral deposits should straddle the demarcation line, an agreement is to be reached on the development of the structure or deposit and on the most effective manner to equally share the profits resulting from the development.

• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.682-688
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• 2017

Fresh japanese anise (Illicium anisatum L.) tree leaves were collected and ground after drying. The essential oils of the leaves were analyzed by gas chromatography-mass spectrometry (GC-MS) using headspace (HS) and solid phase-microextra (SPME) methods. Volatile components of the leaves were identified 21 and 65 components in HS and SPME, respectively. The main components of the essential oils obtained by HS method were eucalyptol (36.7%), (+)-sabinene (15.61%), ${\delta}$-3-carene (6.87%), ${\alpha}$-pinene (6.07%), ${\gamma}$-terpinen (5.72%), ${\alpha}$-limonene (5.26%), ${\beta}$-myrcene (4.13%), ${\alpha}$-terpinene (4.04%) and ${\beta}$-pinene (3.73%). The other components were less than 3.5%. SPME method also showed that eucalyptol (17.88%) was main. The other were 5-allyl-1-methoxy-2 (13.29%), caryophyllene (6.09%), (+)-sabinene (5.60%), ${\alpha}$-ocimene (4.89%) and ${\beta}$-myrcene (3.73%), and the rest were less amounts than 3.5%. This work indicated that many more volatile components were isolated, comparing to the previous literature data and that SPME method was much more effective than HS method in the analysis of the volatile components.

• Safety and Health at Work
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• 제6권1호
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• pp.30-34
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• 2015

Background: The purpose of this study was to examine the cohesions status of the coordination within response teams in the emergency response team (ERT) in a refinery. Methods: For this study, cohesion indicators of social network analysis (SNA; density, degree centrality, reciprocity, and transitivity) were utilized to examine the coordination of the response teams as a whole network. The ERT of this research, which was a case study, included seven teams consisting of 152 members. The required data were collected through structured interviews and were analyzed using the UCINET 6.0 Social Network Analysis Program. Results: The results reported a relatively low number of triple connections, poor coordination with key members, and a high level of mutual relations in the network with low density, all implying that there were low cohesions of coordination in the ERT. Conclusion: The results showed that SNA provided a quantitative and logical approach for the examination of the coordination status among response teams and it also provided a main opportunity for managers and planners to have a clear understanding of the presented status. The research concluded that fundamental efforts were needed to improve the presented situations.

• 복식문화연구
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• 제18권2호
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• pp.371-381
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• 2010

The pine needles can be used for four seasons in normal living and it can be taken friendly everywhere as it is distributed over 50% in Korea. The pine needles consist of vitamins, protein, minerals, essential oil and enzyme related to antimicrobial activity. It has effect like high blood pressure, neuralgia and hanged over by terpene, glucokinin, rutin, apigenic acid and tannin. Also the extract of them can be used for dyeing of fabrics. However, the extract components and effects of them are not well known yet. Therefore, the purpose of this study was to investigate the volatile components of the pine needles extract and functionality. The pine needles extract was dyed into various fabrics(nylon, silk, wool and soybean) and mordanted with Al, Cu, Cr, Fe and Sn. The extracted aroma compounds were compared by gas chromatography-mass spectrometry. The major volatile compounds of pine needles verified by using SPME were alpha-pinene, beta-pinene, beta-phellandrene, caryophyllene, ethanon, benzen. A total of 15 compounds were identified by using the SPME fibers. In the UV-visible spectra, the maximum absorption of wavelength of the pine needles ethanol extract appeared at 460, 630nm for chlorophyll component and at 237, 281nm for tannin component with the pine needles distilled water extract. Most of sample showed high antibacterial effect in none mordant but wool fabric showed high antibacterial effect in mordants. The result of UV block test showed a superior ability of blocking ultraviolet ray infiltration in all sample.

• 한국CDE학회논문집
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• 제19권4호
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• pp.390-401
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• 2014

ISO 15926 is an international standard for integration of lifecycle data for process plants including oil and gas facilities. From the viewpoint of information modeling, ISO 15926 Parts 2 provides the general data model that is designed to be used in conjunction with reference data. Reference data are standard instances that represent classes, objects, properties, and templates common to a number of users, process plants, or both. ISO 15926 Parts 4 and 7 provide the initial set of classes, objects, properties and the initial set of templates, respectively. User-defined reference data specific to companies or organizations are defined by inheriting from the initial reference data and the initial set of templates. In order to support the extension of reference data and templates, an editor that provides creation, deletion and modification functions of user-defined reference data is needed. In this study, an editor for reference data based on ISO 15926 was developed. Sample reference data were encoded in OWL (web ontology language) according to the specification of ISO 15926 Part 8. iRINGTools and dot15926Editor were benchmarked for the design of GUI (graphical user interface). Reference data search, creation, modification, and deletion functions were implemented with XML (extensible markup language) DOM (document object model), and SPARQL (SPARQL protocol and RDF query language).

• 한국환경과학회지
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• 제14권6호
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• pp.543-553
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• 2005

In recent days, photochemical smog due to the rapid industry development and vehicle increasement has become a critical pollutant in the metropolitan area and the number of ozone alarm signal has increased every year. This research was performed to evaluate VOCs emission source characteristics and concentration of VOCs in Daegu. The site average concentration was observed in the following order: industrial area > commercial area > residential area. Most of the VOCs species except toluene showed variations with higher concentration during nighttime, and lower concentration during the daytime. The major VOCs of stationary emission source were BTEX(benzene, toluene, ethylbenzene. xylene) and methylene chloride, trichloroethene and styrene. Also, those of automobile exhaust were toluene and benzene. Also, the major VOCs concentration emited by the vehicle fuel was observed in the following order: gasoline > light oil > liquefied petroleum gas (L.P.G). Correlation coefficients values were estimated between major VOCs such as toluene, ethylbenzene, m,p-xylene, o-xylene. Results showed that correlation coefficient values were significant magnitude above 0.76. Also, there showed highly significant correlations among ethyl benzene, m,p-xylene, and o-xylene concentration(Pearson correlation coefficients, r=0.868-0.982). Calculated correlation coefficients among commercial area,industrial area and residential area were 0.934-0.981, they showed high correlation. There showed highly correlation between stationary emission source and industrial area, compared with commercial area and residential area. Also, calculated correlation coefficients among commercial area, industrial area, residential area and automobile exhaust were 0.732, 0.725, 0.777, respectively.

• Structural Engineering and Mechanics
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• 제51권5호
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• pp.755-771
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• 2014

Environmental changes, especially global climate change, are creating new challenges to the development of the Arctic regions, which have substantial energy resources. And attention to offshore structures has increased with oil and gas development. The structural impact response of an explosion-resistant profiled blast walls normally changes when it operates in low temperatures. The main objectives of this study are to investigate the structural response of blast walls in low temperature and suggest useful guidelines for understanding the characteristics of the structural impact response of blast walls subjected to hydrocarbon explosions in Arctic conditions. The target temperatures were based on the average summer temperature ($-20^{\circ}C$), the average winter temperature ($-40^{\circ}C$) and the coldest temperature recorded (approximately $-68^{\circ}C$) in the Arctic. The nonlinear finite element analysis was performed to design an explosion-resistant profiled blast wall for use in Arctic conditions based on the behaviour of material properties at low temperatures established by performing a tensile test. The conclusions and implications of the findings are discussed.

• 비파괴검사학회지
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• 제23권3호
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• pp.263-269
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• 2003

누설자속 (magnetic flux leakage: MFL) 신호는 매설된 송유관이나 가스관에 생성된 부식결함의 검사에 이용된다. 배관의 외 내부 면의 단일 원형 홈 (pit) 깊이와 부피응력 (bulk stress)이 축 (x) 방향, 원주 (y) 방향 및 방사상 (z) 방향의 누설자속에 미치는 영향을 3차원 유한요소법을 이용하여 계산하였다. 자기이방성 물질을 이용하여 부피인장응력 (bulk tensile stress)과 수직 응력에 의한 MFL 신호변화를 계산하였다. 배관의 축 및 방사상 방향의 MFL 신호는 배관 외 내부 면의 결함 길이가 깊어질수록, 부피인장응력이 커질수록 MFL 신호는 증가하였다 그러나 원주 방향의 MFL 신호는 결함 깊이와 부피인장응력에 영향을 거의 받지 않았다.

• Computers and Concrete
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• 제21권6호
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• pp.717-726
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• 2018

Concrete pipelines are the most efficient and safe means for gas and oil transportation over a long distance. The use of nano materials and nono-engineering can be considered for enhancing concrete pipelines properties. the tests show that $SiO_2$ nanoparticles can improve the mechanical behavior of concrete. Moreover, severe hazard for pipelines is seismic ground motion. Over the years, scientists have attempted to understand pipe behavior against earthquake most frequently via numerical modeling and simulation. Therefore, in this paper, the dynamic response of underwater nanocomposite submerged pipeline conveying fluid is studied. The structure is subjected to the dynamic loads caused by earthquake and the governing equations of the system are derived using mathematical model via Classic shell theory and Hamilton's principle. Navier-Stokes equation is employed to calculate the force due to the fluid in the pipe. As well, the effect of external fluid is modeled with an external force. Mori-Tanaka approach is used to estimate the equivalent material properties of the nanocomposite. 1978 Tabas earthquake in Iran is considered for modelling seismic load. The dynamic displacement of the structure is extracted using differential quadrature method (DQM) and Newmark method. The effects of different parameters such as $SiO_2$ nanoparticles volume percent, boundary conditions, thickness to radius ratios, length to radius ratios, internal and external fluid pressure and earthquake intensity are discussed on the seismic response of the structure. From results obtained in this paper, it can be found that the dynamic response of the pipe is increased in the presence of internal and external fluid. Furthermore, the use of $SiO_2$ nanoparticles in concrete pipeline reduces the displacement of the structure during an earthquake.