• 한국해양공학회지
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• 제21권5호
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• pp.18-24
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• 2007

The environmental value of coastal vegetation has been widely recognized. Coastal vegetation such as reed forests and seaweed performs several useful functions, including maintaining water quality, supporting fish (and, thus, fisheries), protecting beaches and land from wave attack, stabilizing sea beds and providing scenic value. However, studies on the physical and numerical process of wave propagation, sediment transport and bathymetric change are few and far between compared to those on the hydrodynamic roles of coastal vegetation. In general, vegetation flourishing along the coastal areas attenuates the incident waves through momentum exchange between stagnated water mass in the vegetated area and rapid mass in the un-vegetated area. This study develops a numerical model for describing the wave attenuation and sediment transport in a wave channel in a vegetation area. By comparing these results, the effects of vegetation properties, wave properties and model parameters are clarified.

• Advances in environmental research
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• 제3권1호
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• pp.45-69
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• 2014

The groundwater has been a major source of water supply throughout the ages. Around 50% of the rural as well as urban population in the developing countries like India depends on groundwater for drinking. The groundwater is also an important source in the agriculture and industrial sector. In many parts of the world, groundwater resources are under increasing threat from growing demands, wasteful use and contamination. A good planning and management practices are needed to face this challenge. A key to the management of groundwater is the ability to model the movement of fluids and contaminants in the subsurface environment. It is obvious that the contaminant source activities cannot be completely eliminated and perhaps our water bodies will continue to serve as receptors of vast quantities of waste. In such a scenario, the goal of water quality protection efforts must necessarily be the control and management of these sources to ensure that released pollutants will be sufficiently attenuated within the region of interest and the quality of water at points of withdrawal is not impaired. In order to understand the behaviour of contaminant transport through different types of media, several researchers are carrying out experimental investigations through laboratory and field studies. Many of them are working on the analytical and numerical studies to simulate the movement of contaminants in soil and groundwater of the contaminant transport. With the advent of high power computers especially, a numerical modelling has gained popularity and is indeed of particular relevance in this regard. This paper provides the state of the art of contaminant transport and reviews the allied research works carried out through experimental investigation or using the analytical solution and numerical method. The review involves the investigation in respect of both, saturated and unsaturated, porous media.

• 한국수정란이식학회지
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• 제12권3호
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• pp.307-313
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• 1997

Experiments were conducted to assess the effect of quality and viability of bovine blastocysts derived from in-vitro culture(IVC) of in vitro matured and fertilized(IVM-IVF) oocytes during their transport 2 hours. Follicular oocytes were collected form ovaries obtained at a slaughterhouse and were cultured for 24 hours in TCM-199. The IVM oocytes were fertilized in vitro with caudal epididymis spermatozoa. Fertilized oocytes were cultured for 7 to 9 days, and embryos that developed to the blastocyst stage were used for the experiment. The blastocysts, packed in straws with storage medium that consisted TCM-199 with HEPES equilibratd in air and supplemented with 10% FCS were transported at 39~(2.0 h). The quality of blastocysts was assessed and ranked as A(excel-lent), B(Good), fair or poor after transportation. The percentages of A and B grade blastocysts after transport duration for < 1 hours(97.7%) were similar to the result from transport duration for 1~2 hours (92.9%) and 2~3 hours(89.6%), but significantly(P<0.05) higher than transpot duration for 3~4 hours(76.3%). The percentages of A and B grade blastocysts after transport duration for two hours from developed blastocyst at 7day(100%) and 8day(85.0%) were higher 9day(96.6%) and >9day (40.0%). And early to expanded blastocyst produced in vitro were transferred to recipient cow by additional embryos at 7 and 8th day after AI. Three of them were pregnant to term and produced four twin calves, and two calves was premature birth. The gestation lengths of male to female and female to female twin were 282 and 281 days, respectively. And birth weight of twin calves were male to female(22.Skg) and female to female twin(20.3Okg), respectively.

• 한국수자원학회논문집
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• 제31권1호
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• pp.85-93
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• 1998

본 연구는 도시하천인 한강 하류부에 2차원 유한요소모형을 적용하여 하천의 수리학적 특성에 따른 오염물질의 거동특성을 모의하고 예측하기 위한 것으로서 흐름상태를 분석할 수 있는 RMA-2V 모형과 동적 수질예측이 가능한 RMA-4모형을 이용하였다. 2차원 유한요소모형을 사용하여 수질의 거동특성을 모의하여 본 결과 유량 및 유속의 변화는 오염물질의 이송확산에 큰 영향을 미치는 것으로 나타났으며, 탄천 및 중랑천은 대상구역내의 수질오염에 큰 영향을 미치는 것으로 나타났다. 불시의 오염사고가 발생했을 때 오염물질이 하류부로 이동함에 따라 최대 COD 값은 감소하고,오염물질이 영향을 미치는 지속기간은 커지는 것을 알 수 있었고, 전체적으로 좌·우안의 오염물질의 농도차가 크게 나타났으며, 이로써 한강과 같은 대하천의 경우 실시간 예측시 2차원 해석이 필요한 것으로 나타났다.

• 한국대기환경학회지
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• 제26권6호
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• pp.666-682
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• 2010

The forecasting system for Today's and Tomorrow's PM10 was developed based on the statistical model and the forecasting was performed at 9 AM to predict Today's 24 hour average PM10 concentration and at 5 PM to predict Tomorrow's 24 hour average PM10. The Today's forecasting model was operated based on measured air quality and meteorological data while Tomorrow's model was run by monitored data as well as the meteorological data calculated from the weather forecasting model such as MM5 (Mesoscale Meteorological Model version 5). The observed air quality data at ambient air quality monitoring stations as well as measured and forecasted meteorological data were reviewed to find the relationship with target PM10 concentrations by the regression analysis. The PM concentration, wind speed, precipitation rate, mixing height and dew-point deficit temperature were major variables to determine the level of PM10 and the wind direction at 500 hpa height was also a good indicator to identify the influence of long-range transport from other countries. The neural network, regression model, and decision tree method were used as the forecasting models to predict the class of a comprehensive air quality index and the final forecasting index was determined by the most frequent index among the three model's predicted indexes. The accuracy, false alarm rate, and probability of detection in Tomorrow's model were 72.4%, 0.0%, and 42.9% while those in Today's model were 80.8%, 12.5%, and 77.8%, respectively. The statistical model had the limitation to predict the rapid changing PM10 concentration by long-range transport from the outside of Korea and in this case the chemical transport model would be an alternative method.

• Journal of Animal Science and Technology
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• 제45권5호
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• pp.857-864
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• 2003

여름철 수송시간이 돼지의 혈액성상 및 돈육품질에 미치는 영향을 구명하고자, 생체중 110kg 내외의 비육돈 120두를 공시하여 실험하였다. 수송시간은 농가에서 도축장까지 20분과 2시간으로 하였고 계류는 약 1시간 30분 실시하였다. 돼지 혈액은 도축장 하차직후 채취하였다. 관행적인 방법으로 도축 후 도체특성을 조사하였다. 도축 1시간 후 pH$_1$과 도체의 피부손상을 측정한 후, 도체를 냉각시키고 사후 24시간에 최종 pH$_{u}$ 및 돈육품질을 조사하였다. 20분과 2시간 수송사이 도체중, 등지방두께 및 도체등급은 차이를 나타내지 않았다. 돼지의 심리적 스트레스 수준을 측정하는 Cortisol과 물리적 스트레스 수준은 측정하는 LDH는 2시간 수송이 20분 수송에 비해 유의하게(P〈0.05) 높게 나타났다. 돈육의 이화학적 특성 중 pH$_{u}$는 20분 수송이 높은 경향을 나타냈고, 가열 감량, 육즙 감량 및 경도는 차이를 나타내지 않았다. CIE L$^{*}$, a$^{*}$ b$^{*}$와 주관적인 육색인 NPPC에도 수송시간에 의해 영향을 받지 않았고 또한 도체의 피부손상도 차이가 인정되지 않았다. 이상의 결과, 돈육품질은 현저한 차이를 보이지 않았지만 2시간 수송한 돼지가 스트레스를 많이 받는 것으로 나타났다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.412-416
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• 2001

Among water quality models, WASP5 was applied to Boryeong freshwater lake, as a part of Water Quality Management System. The WASP modeling system is a generalized modeling framework for contaminant fate and transport in surface waters. The simulated result was compaired with actual measurement. So, before and after making freshwater lake were compaired. After this research, the lake may have eutrophication and water quality would be worse after making the lake as freshwater lake. Therefore, to make the freshwater lake better, more appropriate plan is necessary.

• Journal of the Optical Society of Korea
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• 제19권4호
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• pp.340-345
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• 2015

The Internet traffic is forecasted to grow at a compound annual rate of 21 % from 2013 to 2018, according to surveys carried out by Cisco [1]. Network resources are significantly over-provisioned in today's networks, and it is quite common to see link utilization in the 30-40% range [2]. Additionally, the multi-media services have widely divergent bandwidth and Quality of Experience (QoE) requirements. Unfortunately, the huge transmission capacity will increase the power consumption of network equipment [3]. Applications Coordinated with Transport, Internet Protocol and Optical Networks (ACTION) [4] has been proposed to realize a multi-QoE, application-centric, and highly energy-efficient network that leverages flexible elastic optical network technologies [5-7]. This paper provides key network technologies for realizing the ACTION, which are a virtual optical slice core network and a Time Division Multiplexing (TDM)-based deterministic active optical access network.

• 한국컴퓨터정보학회논문지
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• 제25권3호
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• pp.169-176
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• 2020

본 연구는 이송 중 심장정지 환자에게 가슴압박의 질을 높일 수 있는 방법을 제안하였다. 병원 전 단계에서 심장정지 환자에게 심폐소생술을 제공 할 때 구급차에 고정되어 있는 3점식 벨트를 사용하여 가슴압박의 질을 높일 수 있다. 119구급대원이 가슴압박 방법과 더불어 3점식 고정벨트를 착용한 경우 가슴압박의 질이 더 높아졌다. 또한 구급대원의 위험에 노출될 가능성도 적어졌다. 따라서 이송 중 구급차 안에서 3점식 고정벨트를 착용한 경우 119 구급대원은 안전을 확보할 수 있게 되고 심장정지 환자에게는 고품질의 가슴압박을 제공 할 수 있다.

• 한국컴퓨터정보학회논문지
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• 제18권5호
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• pp.133-145
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• 2013

본 연구의 목적은 교통정보 데이터의 품질특성을 분석하여 신뢰성 있는 교통정보 평가기준을 마련하고, 교통정보 데이터의 평가 프레임 워크와 같은 평가절차를 제공함으로써 효율적인 교통정보센터 운영관리에 기여하고자 한다. 이러한 목적을 달성하기 위하여 체계공학 분야에서 활용되고 있는 교통정보 품질관리를 위한 온톨로지 기법을 통하여 데이터 특성을 분석하고 데이터베이스화 하였다. 본 연구의 지능형 교통체계에서 시스템적인 데이터베이스는 다양한 분야의 부체계 개발 및 구성품 요소설계의 지표 자료로 활용될 것으로 기대한다