• 한국건설순환자원학회논문집
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• 제10권3호
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• pp.300-306
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• 2022

본 연구에서는 제주도 해안가의 대기중 염분 분포 특성을 파악하였다. 이를 위해 제주도를 동, 서, 남, 북부지역의 4개 지역으로 구분하여 대기중 염분량을 조사하고, 지역별, 계절별 특징을 분석하였다. 아열대 기후이면서 섬으로 형성된 제주도는 대기중 염분량 분포에 있어서 지역별 편차가 크며 가장 높은 지역인 동부와 가장 낮은 지역인 남부 지역은 6배 이상 차이가 났다. 계절별 특징으로는 동부와 서부는 태풍의 영향으로 각 각 여름/가을철과 여름철이 높고, 북부는 북서풍의 영향으로 겨울철이 높으며, 남부는 여름철이 높았다. 한편 국내 동, 서, 남해안의 대기중 염분량과 비교하여 제주도는 높은 경향이 있다.

• 한국환경과학회지
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• 제18권10호
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• pp.1089-1101
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• 2009

In this paper, changes in the intensity (e.g., central pressure and maximum sustained wind speed) of Tropical Cyclone (TC) in summer in the regions located at $30^{\circ}N$ in East Asia from 1988 to 1991 were found. The intensity of TC from 1991 to 2007 was much higher than that of TC from 1965 to 1988. The reason for this was that the frequency of TCs passing China from 1991 to 2007 was much lower than that of TCs from 1965-1988 because a northeasterly wind caused by high-pressure circulation in East Asia got severer along the East Asian coast. Instead, TCs moved from the eastern region of the Tropical West Pacific to Korea and Japan mainly after passing the East China Sea due to the low-pressure circulation strengthened in the subtropical waters of East Asia. In addition, low Vertical Wind Shear (VWS) was created along the mid-latitude regions of East Asia and the main path of TCs from 1991 to 2007. Most of the regions in the Northwestern Pacific showed higher Sea Surface Temperature (SST) from 1991 to 2007, and had a good environment where TCs were able to maintain a higher intensity on the mid-latitude. In particular, a low sensible heat flux occurred due to high snow depth in East Asia in the spring of 1991 to 2007. Accordingly, the lower layer of East Asia showed high-pressure circulation, and the sea surrounding East Asia showed low-pressure circulation. Thus, the typical west-high, east-low pattern of winter atmospheric pressure was shown. The possibility of snowfall in East Asia in spring to be used as a factor for predicting the summer intensity of TC in the mid-latitude regions of East Asia was insinuated. The characteristics of TC in a low-latitude region were the same in Korea. The latest intensity of TCs got higher, and the landing location of TCs gradually changed from the west coast to the south coast.

• 신재생에너지
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• 제8권2호
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• pp.6-13
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• 2012

Due to global warming, the need to secure an alternative resource has become more important nationally. Having very strong current on the west coast with up to 10 m tidal range, there are many suitable site for the application of TCP (Tidal Current Power) in Korea. On the south west regions between many islands that create strong current in the narrow channels. The rotor is one of the essential components which can convert tidal current energy into rotational energy to generate electricity. The design optimization of rotor is very important to maximize the power production. The performance of rotor can be determined by various parameters including number of blades, shape, sectional size, diameters and etc. This paper introduces the multi-layer vertical axis tidal current power system which can be applied to offshore jetties and piers effectively. Various cases of VAT turbine were designed. Specifically, the number of blades and turbine shape are changed in several cases. Also, performance analysis was carried out by CFD.

• 한국해양공학회지
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• 제23권1호
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• pp.109-113
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• 2009

Several tidal current power plants are being planned and constructed in Korea utilizing the strong tidal currents along the west and south coasts. A tidal current reaches 9.7 m on the west coast; there are few potential regions for tidal current power generation. The construction of a dam to store water can prevent the circulation of water, causing a great environmental impact on the coast and estuary. The tidal barrage could produce a large amount of power, but it should be carefully considered. The purpose of developing renewable energies is to minimize the environmental impact and to maximize the utilization of clean energy. To produce a great quantity of power, tidal current farms require the placement of numerous units in the ocean. The power generation is very dependent on the size of the rotor and the incoming flow velocity. Also, the interactions between devices contribute greatly to the production of power. The efficiency of a power farm is estimated to determine the production rate. This paper introduces 3 D interaction problems between rotating rotors, considering the axial, transverse, and diagonal distances between horizontal axis tidal current devices.

• 한국지역지리학회지
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• 제1권1호
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• pp.45-60
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• 1995

한국의 온대저기압성 강수에 대하여 10년간(1981년$\sim$1990년) 60개 지점의 저기압성 강수와 관련된 43개 강수자료를 이용하여 지역구분을 시도하였다. 먼저 인자분석(因子分析)을 통하여 요인별 고유치를 분석하여 인자점수(因子點數)의 지역분포를 고찰한 후, 군집분석의 Ward법을 적용하여 강수지역을 구분하고 구분지역별로 강수특성을 고찰하였다. 온대저기압성 강수와 관련된 43개 변수를 이용한 인자분석(因子分析)에서 고유치(固有値)가 1.0이상의 요인은 7개이며, 전변동량(全變動量)의 86%를 설명한다. 제1요인은 중서부지역의 강수특성을 설명해주며 기여율이 40.9%로 가장 높게 나타났다. 군집(群集)분석의 Ward법에 의한 한궁의 온대저기압성 강수지역은 (1) 경기 영서북부지역 (2) 영동 울릉도지역 (3) 호서 영서남부지역 (4) 호남 북서제주지역 (5) 남동제주지역 (6) 영남북부지역 (7) 영남남부지역 등 7개의 대지역과, 22개 중지역으로 구분되었다. 더불어 강수지역의 경계선 설정에는 저기압의 이동경로와 유일기류의 방향, 산맥의 주향(走向) 등이 많은 영향을 주고 있음을 알 수 있었다.

• 한국환경생태학회지
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• 제21권1호
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• pp.74-81
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• 2007

본 연구는 한국 갯기름나물의 지형적 분포와 해식애 군집구조의 기초자료로 제공하기 위하여 해안과 지형별 종조성 및 생육양상을 조사한 바 이의 결과를 요약하면 다음과 같다. 갯기름나물과 동반 출현하는 식물은 57과 130속에 속한 170 분류군이었으며, 과별로는 국화과가 30 분류군으로 가장 많았다. 출현빈도가 가장 높은 식물은 해국(54.1%)이었고, 해안별로는 동해안과 서해안에서 해국, 남해안에서 억새의 출현빈도가 가장 높았다. 해안별 공통종은 서해안과 남해안간이 35.6%(47 분류군)로서 가장 높았고 다음으로 동해안과 서해안(30.4%), 동해안과 남해안(26.4%)순이었다. 갯기름나물이 출현하는 해안지형은 경사도 $17.4^{\circ}$의 해식애 암석해안, 평탄면, 암괴원, 수평절리, 수직절리, 요철지형이었고 지형 별 분포지역은 암석해안이 61 지역으로 가장 많았다. 군도에 따른 갯기름나물의 생육양상은 군도계급 3이 83지역(54.6%)으로서 가장 많았다.

• 한국지반환경공학회 논문집
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• 제13권4호
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• pp.77-91
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• 2012

최근 우리나라는 국토의 고도 이용과 지역 간의 균형발전을 도모하기 위한 목적으로 택지 및 단지, 도로, 항만 및 공항 등의 건설이 증가하고 있는 추세이다. 현재도 많은 공사들이 연약한 지반에서 실시되고 있다. 이로 인해 건설현장에서 지반의 장기침하, 파괴, 부등침하, 국지적인 구조물 손상 등의 공학적인 문제들이 지속적으로 보고되고 있다. 특히, 연약지반이 비교적 두껍게 발달한 서 남해안 지역과 내륙지역의 연약지반 위에 축조되는 각종 구조물, 도로 등의 경우 필연적으로 하중에 의한 지반의 장기침하가 발생하게 된다. 따라서, 본 연구에서는 기존의 장기침하량 예측기법들인 쌍곡선법, 호시노법, $\sqrt{S}$법, 아사오카법 등의 지역별 적정 분석기법을 검토하는 한편, 일반화된 산정식의 도출을 통한 새로운 예측기법에 대한 연구를 수행하여 토질특성 및 시공조건에 대한 상관관계를 분석하고 장기적인 침하특성과의 연관계수를 도출하였다. 수식의 검증을 위해 16개 지역의 계측자료와 수치해석 결과를 비교 및 분석을 실시하였다.

• Water Engineering Research
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• 제7권1호
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• pp.1-8
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• 2006

Recently, the population growth and agricultural development are rapidly undergoing in the South-West Texas. The junction of three river basins such as Lavaca river basin, Colorado-Lavaca Coastal basin and Lavaca-Guadalupe Coastal basin, are interesting for non-point and point source pollutant modeling: Especially, the 2 basins are an intensively agricultural region (Colorado-Lavaca Coastal/Lavaca-Guadalupe Coastal basins) and several cities are rapidly extended. In case of the Lavaca river basin, there are many range land. Several habitat types wide-spread over three relatively larger basins and five wastewater discharge regions are located in there. There are different hazardous substances which have been released. Total nutrient loads are composed of land surface load and river load as Non-point source and discharge from wastewater facilities as point source. In 3 basins region, where point and non-point sources of poll Jtion may be a big concern, because increasing fertilizers and pesticides use and population cause. This project objective seeks to how to assess and control the accumulation of non-point and point source and discuss the main impacts of agriculture and environmental concern as non-point source with water quality related to pesticides, fertilizer, and nutrients and as point source with wasterwater discharge from cities. The GIS technique has been developed to aid in the point and non-point source analysis of impacts to natural resource within watershed. This project shows the losses in $kg/km^2/year$ of BOD (Biological Oxygen Demand), TN (Total Nitrogen) and TP (Total Phosphorus) in the runoff from the surface of 3 basins. In the next paper, sediment contamination will show how to evaluate in Estuarine habitats of these downstream.

• Food Science and Biotechnology
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• 제18권2호
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• pp.367-373
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• 2009

Regional variation in the fatty acid content of shellfish was investigated on 5 species of Korean shellfish including murex shell, ark shell, jack-knife clam, orient hard clam, and little neck clam that were originated from 2 geographically different regions in Korea (Region 1: South coast, $34-35^{\circ}N$, $127-129^{\circ}E$; Region 2: West coast, $36-38^{\circ}N$, $126-127^{\circ}E$). Significant regional difference in total fatty acids content was observed in murex shell and little neck clam (p<0.01), but not in the other species of shellfish. The contents of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids including n-3 and n-6 fatty acids were appreciably higher in murex shell from Region 2 and in little neck clam from Region 1 than the shellfish originated from their counterpart areas (p<0.05). Nevertheless, relative percentages of the fatty acids remained constant within same species regardless of geographic regions or species. Considering the facts of that the fish/shellfish are unique sources of n-3 fatty acids and a little neck clam is the most-consumed shellfish in Korea, n-3 fatty acids intake might vary with the habitat of the shellfish that Koreans consume.

• 유통과학연구
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• 제21권4호
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• pp.121-129
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• 2023

Purpose: Market basket analysis is one of the most frequently used methods in the retail industry today as a technique to discover the product association. It is empirically analyzed how these product associations differ regionally in the case of the United States. Research design, data, and methodology: Based on the purchasing data of consumer panels collected from 49 US states, the association rules for each state was extracted with the corresponding lift values indicating product association. The difference in lift values in 49 states by the association rule was compared and tested for 49 states and for 4 census regions (Northeast, Midwest, South, West). Results: The association rules of 3/4 of the same association rules show positive associations or negative associations depending on the lift values of the states. There were significant differences in the lift values for 49 states, and for 4 census regions. These significant differences in the lift values were found to be related to the distance between states and whether states belong to the same census region. Conclusions: Retail product associations shown by market basket analysis may vary depending on regional distance or regional heterogeneity. It is necessary to pay attention to these points in multi-store environment.