• Journal of Information Technology Applications and Management
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• 제10권4호
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• pp.149-157
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• 2003

In this paper, we propose a ceil model based on the wraparound method to simulate the hierarchical CDMA cellular system in an effective and efficient manner. The model uses the minimal number of cells by considering only one tier but compensates the interference by other cells in the higher tiers sufficiently. Various numerical tests demonstrate that the proposed model can be used to simulate the complex and large-sized hierarchical cellular system effectively. Especially, the interference compensation can reduce the required simulation time to 1/100 for 10 tiers cellular system.

• 한국토양비료학회지
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• 제19권3호
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• pp.187-194
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• 1986

호남지방(湖南地方)에 분포(分布)되어 있는 공덕(孔德), 봉남(鳳南) 및 김제통(金堤統)이 갖는 이탄(泥炭)과 흑이(黑泥)의 이화학적특성(理化學的特性), 섬유소함량(纖維素含量) 및 부식화도(腐植化度)와 이탄(泥炭)과의 상관관계(相關關係), 합리적(合理的) 토양관리(土壤管理)를 위(爲)한 이들 토양(土壤)의 지지력(支持力)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 이탄(泥炭)의 부식화도(腐植化度)는 23 정도(程度)인데 반(反)하여 흑이(黑泥)는 45~71로서 흑이(黑泥)의 부식화도(腐植化度)가 더욱 진전(進展)되었으며, 봉남통(鳳南統)의 흑이(黑泥)에 비(比)해 흑이(黑泥)의 위치(位置)가 표상(表上)에 가까운 김제통(金堤統)의 부식화도(腐植化度)가 컸었다. 2. 부식화도(腐植化度)가 높은 유기물층(有機物層)일수록 pH가 높고 K, $P_2O_5$, B+S 및 가비중(假比重)이 높으며, OM, T-C, T-N, Na, $SiO_2$, 및 섬유소함량(纖維素含量)은 감소(減少)되었다. 3. 이탄(泥炭)과 흑이(黑泥)의 특성중(特性中) 섬유소함량(纖維素含量)과 이화학적특성(理化學的特性)과의 상관관계(相關關係)에 있어서 pH, T-N, $P_2O_5$ 및 Ash, 가비중(假比重)은 유의성(有意性)있는 부(負)의 상관(相關), OM, CEC, T-C, PAC, C/N, C/P 등(等)은 유의성(有意性)있는 정(正)의 상관관계(相關關係)를 보였으며, 부식화도(腐植化度)와 이들 성분(成分)과의 관계(關係)는 섬유소함량(纖維素含量)과 반대(反對)의 상관관계(相關關係)를 보였다. 4. 토양(土壤)의 토층별(土層別) Cone 지지력(支持力)은 유기질토층(有機質土層)이 두껍고 배수(排水)가 불량(不良)한 공덕통(孔德統)에서 전토층(全土層)의 Cone지지력(支持力)이 낮았으며, 유기질토층(有機質土層)이 얇아서 무기질토양(無機質土壤)과 유사(類似)한 김제통(金堤統)에서 가장 높았다.

• Journal of Communications and Networks
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• 제12권2호
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• pp.122-129
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• 2010

Energy conservation is one of the most important issues for evaluating the performance of wireless sensor network (WSN) applications. Generally speaking, hierarchical clustering protocols such as LEACH, LEACH-C, EEEAC, and BCDCP are more efficient in energy conservation than flat routing protocols. However, these typical protocols still have drawbacks of unequal and high energy depletion in cluster heads (CHs) due to the different transmission distance from each CH to the base station (BS). In order to minimize the energy consumption and increase the network lifetime, we propose a new hierarchical routing protocol, distance aware intelligent clustering protocol (DAIC), with the key concept of dividing the network into tiers and selecting the high energy CHs at the nearest distance from the BS. We have observed that a considerable amount of energy can be conserved by selecting CHs at the nearest distance from the BS. Also, the number of CHs is computed dynamically to avoid the selection of unnecessarily large number of CHs in the network. Our simulation results showed that the proposed DAIC outperforms LEACH and LEACH-C by 63.28% and 36.27% in energy conservation respectively. The distance aware CH selection method adopted in the proposed DAIC protocol can also be adapted to other hierarchical clustering protocols for the higher energy efficiency.

• 한국대기환경학회지
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• 제28권3호
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• pp.233-248
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• 2012

The national emission from energy sector accounted for 84.7% of all domestic emissions in 2007. Of the energy-use emissions, the emission from mobile source as one of key categories accounted for 19.4% and further the road transport emission occupied the most dominant portion in the category. The road transport emissions can be estimated on the basis of either the fuel consumed (Tier 1) or the distance travelled by the vehicle types and road types (higher Tiers). The latter approach must be suitable for simultaneously estimating $CO_2$, $CH_4$, and $N_2O$ emissions in local administrative districts. The objective of this study was to estimate 31 municipal GHG emissions from road transportation in Gyeonggi Province, Korea. In 2008, the municipalities were consisted of 2,014 towns expressed as Dong and Ri, the smallest administrative district unit. Since mobile sources are moving across other city and province borders, the emission estimated by fuel sold is in fact impossible to ensure consistency between neighbouring cities and provinces. On the other hand, the emission estimated by distance travelled is also impossible to acquire key activity data such as traffic volume, vehicle type and model, and road type in small towns. To solve the problem, we applied a hierarchical cluster analysis to separate town-by-town road patterns (clusters) based on a priori activity information including traffic volume, population, area, and branch road length obtained from small 151 towns. After identifying 10 road patterns, a rule building expert system was developed by visual basic application (VBA) to assort various unknown road patterns into one of 10 known patterns. The expert system was self-verified with original reference information and then objects in each homogeneous pattern were used to regress traffic volume based on the variables of population, area, and branch road length. The program was then applied to assign all the unknown towns into a known pattern and to automatically estimate traffic volumes by regression equations for each town. Further VKT (vehicle kilometer travelled) for each vehicle type in each town was calculated to be mapped by GIS (geological information system) and road transport emission on the corresponding road section was estimated by multiplying emission factors for each vehicle type. Finally all emissions from local branch roads in Gyeonggi Province could be estimated by summing up emissions from 1,902 towns where road information was registered. As a result of the study, the GHG average emission rate by the branch road transport was 6,101 kilotons of $CO_2$ equivalent per year (kt-$CO_2$ Eq/yr) and the total emissions from both main and branch roads was 24,152 kt-$CO_2$ Eq/yr in Gyeonggi Province. The ratio of branch roads emission to the total was 0.28 in 2008.

• 농촌계획
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• 제26권1호
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• pp.23-38
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• 2020

This study is aimed at the deduction of the important priority factors by setting the comprehensive rate in each of the economy, sociability and environmental areas for the sustainable development of fishing villages. As the research methods, review of domestic and overseas literature and Delphi questionnaire survey on experts, and hierarchical structure analysis were executed. Accordingly, this study is aimed at providing the basic data at the time of establishing plans by assessing the level of importance and priorities for each item through the deduction of the elements necessary for the fishing village plan. Key results of the study are as follows. First, as the results of review of domestic and overseas literature related to sustainability indices of fishing villages, a total of 50 items in the areas of economy, sociability and environment were deduced. Second, validity for each area was confirmed through Delphi questionnaire survey on experts. Third, as the results of factor analysis conducted on the basis of the hierarchical structure analysis for detailed items for each sector, 3 factors in the economic area, 2 factors in the social area and 3 factors in environment area were deduced. Fourth, as the results of the relative importance of the higher tiers, economic sector (0.528) displayed results that are more than 2 times higher than the social (0.261) and environmental (0.212) sectors. Establishment of foundation for independent competition (0.105), balanced development of small fishing village (0.086) and population engaged in economic activities in comparison to the fishing village population (0.077) were analyzed as the most important detailed items. Based on these results, experts pointed out that the economic sector is most important for the sustainable development of fishing village and, in detail, priority must be placed on the balanced development on the basis if the extent of independence of the fishing villages, and emphasized activation of residents engaged in economic activities in fishing villages in order to support them. That is, in order to increase the level of independence of the fishing villages, it was determined that there is a dire needs for expansion of diversified specialized businesses and infrastructural facilities through agreement by the residents capable of economic activities, and means of activating fishing villages through securing of budget at the local autonomous government level to provide support for the residents.

• Asian-Australasian Journal of Animal Sciences
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• 제16권10호
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• pp.1501-1509
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• 2003

The simultaneous addition of xylanase (5,600 EXU/kg) and phytase (500 FTU/kg) feed enzymes to wheat-based broiler diets was investigated. Starter, grower and finisher diets, with three tiers of nutrient specifications, were fed to 1,440 broiler chicks kept on deep litter from 1-42 days post-hatch, without and with xylanase plus phytase, to determine the effects of diet type and enzyme supplementation on growth performance. The nutrient specifications of type A diets were standard; energy density and protein/amino acid levels were reduced on a least-cost basis to formulate type B diets and further reduced to type C diets. Phosphorus (P) and calcium (Ca) levels were adjusted in supplemented diets. From 1-42 days post-hatch, diet type significantly influenced growth performance. Birds on type C diets had lower growth rates (2,429 vs. 2,631 g/bird; p<0.001), higher feed intakes (4,753 vs. 4,534 g/bird; p<0.005) and less efficient feed conversion (1.96 vs. 1.72; p<0.001) than birds offered type A diets. Enzyme supplementation increased growth rates by 3.2% (2,580 vs. 2,501 g/bird; p<0.005) and improved feed efficiency by 2.7% (1.80 vs. 1.85; p<0.05) over the entire feeding period. There were no interactions between diet type and enzyme supplementation. At 21 days, 5 out of 30 birds per pen were transferred to cages to ascertain treatment effect on apparent metabolisable energy (AME) and nitrogen (N) retention. Xylanase plus phytase enhanced AME (13.48 to 13.91 MJ/kg DM; p<0.001) and N retention (56.3 to 59.7%; p<0.005). Carcass and breast weights of the caged birds were determined following commercial processing. Diet type significantly influenced breast weight, carcass weight and yield. Birds offered Type A diets, in comparison to Type C diets, supported heavier breast (467 vs. 424 g; p<0.001) and carcass weights (1,868 vs. 1,699 g; p<0.001) with superior carcass yields (71.8 vs. 70.6%; p<0.005). Enzyme addition increased carcass weight by 3.9% (1,752 vs. 1,821 g; p<0.005) and breast weight by 5.8% (431 vs. 456 g; p<0.01) without influencing yields. Feed ingredient costs per kg live weight gain and per kg carcass weight indicated that enzyme addition was economically feasible, where supplementation of Type A diets generated the most effective results. Importantly, soluble and total non-starch polysaccharide and phytate contents of the wheat used were typical by local standards. This study confirms the potential of supplementing wheat-based broiler diets with xylanase plus phytase but further investigations are required to define the most appropriate inclusion rates and dietary nutrient specifications in this context.

• 한국산림과학회지
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• 제81권3호
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• pp.263-272
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• 1992

산지급류하천(山地急流河川)에서는 토석(土石) 등의 이동에 의해 하상퇴적지(河床堆積地)를 형성하게 되며, 현재의 하상면(河床面)은 유역(流域)의 토석이동특성(土石移動特性)을 반영하고 있다. 특히 하상퇴적지(河床堆積地)에 조성되어 있는 천연생(天然生) 동령임분(同齡林分)의 연륜(年輪)은 퇴적지(堆積地) 형성후의 경과년수(經過年數)를 나타낸다. 본 연구에서는 강원도내(江原道內)의 두 개의 산지급류하천(山地急流河川)을 대상으로 하천미지형(河川微地形)과 식물지표(植物指標)에 의해 하상퇴적지(河床堆積地)의 연대학적(年代學的) 해석(解析)을 시도하여 다음과 같은 결과를 얻었다. 1. 산지급류하천(山地急流河川)에 분포하는 하상퇴적지(河床堆積地)의 횡단형상(橫斷形狀)은 계단형상(階段形狀)을 나타내고 있으며, 그 하상면(河床面)에는 상이한 동령임분(同齡林分)이 조성되어 있다. 2. 일반적으로 하상퇴적지(河床堆積地)의 퇴적고(堆積高)에 비례하여 침입하여 있는 수림(樹林)의 연륜수(年輪數)도 증가하였으며, 이는 토사이동(土砂移動)의 규모(規模) 및 빈도(頻度)를 추정하는데에 사용된다. 3. 하상퇴적지(河床堆積地)의 경과년수(經過年數)를 수목(樹木)의 연륜(年輪)에 의해 추정할 수 있으므로 하상퇴적지(河床堆積地)의 시(時) 공간적(空間的) 정보(情報)를 얻는데 식물지표(植物指標)가 유효하게 사용될 수 있다. 4. 퇴적토석량(堆積土石量)은 하상퇴적지(河床堆積地)의 연장(延長), 평균퇴적폭(平均堆積幅), 평균퇴적고(平均堆積高)에 좌우되며, 평균퇴적폭(平均堆積幅), 평균퇴적고(平均堆積高)는 연대(年代)에 비례하여 증가하였다.

• 생물환경조절학회지
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• 제8권1호
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• pp.49-55
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• 1999

플라스틱온실의 생산비용 절감을 위하여 2단 재배를 시도할 때, 그 생육환경의 적정성을 검토하고자 주요 생육환경 요소인 온도, 습도, 광, 양액온도, 공기속도를 비교하였다. 특히 2단 베드의 구성과 광환경과의 관계로부터 광환경 적정화 방법을 제시하고자 하였다. 그 연구 결과를 요약하면 다음과 같다. 상.하 베드 주요 생육환경의 측정결과를 보면, 상단베드의 최고온도는 38.3$^{\circ}C$, 하단베드의 최고온도는 35.5$^{\circ}C$로 나타났다. 양액 온도는 상.하단 모두 20~$25^{\circ}C$ 범위였으며 하단의 온도가 1$^{\circ}C$ 정도 낮은 것을 알 수 있다. 상대습도는 상 하단 모두 야간에는 95% 정도로 높게 나타났으며 주간에는 상단 60~70% 범위, 하단 65~80% 범위로 하단이 10%정도 높게 측정되었다. PPFD는 상.하 베드 모두 200$\mu$mol.m$^{-2}$ .s$^{-1}$ 정도의 값을 보였고 하단의 경우는 100$\mu$mol.m$^{-2}$ .s$^{-1}$ 이하의 값을 보였다. 상.하 베드 일사량을 보면 상단은 200W.m$^{-2}$ 정도이고 하단은 85 W.m$^{-2}$ 이하가 측정되었다. 공기속도는 상.하 베드에서 주간에는 0.1~0.2m.s$^{-1}$ 정도가 측정되었고, 야간에는 0.05m.s$^{-1}$이하로서 거의 정지 상태였다. 온실방위별 하단베드의 광입사 면적을 이론적으로 해석해 보면, 동서동의 경우는 평균 49.9%이고 남북동의 경우는 평균 43%였다. 광입사 면적을 증대하기 위하여 베드를 재구성하면 동서동은 74.3%, 남북동은 60.8% 정도로 각각 25% 및 17.7% 정도의 광입사 면적의 증대효과를 가져왔다.

• 한국패류학회지
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• 제28권2호
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• pp.91-99
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• 2012

일본재첩 (Corbicula japonica) 은 백합목 재첩과에 속하는 담수 및 기수역에 분포하는 소형 이매패류로서 사니질의 얕은 수심에서 서식한다. 섬진강 일본재첩의 어획량은 우리나라 재첩 총 생산량의 약 30%를 차지하며, 경남지역 생산량의 대부분을 차지한다. 섬진강 일본재첩에 대한 정확한 어획 및 자원량에 관한 연구가 미미하여 과학적인 자원평가 및 관리방안 도출이 매우 열악한 실정이다. 본 연구는 섬진강 일본재첩에 대한 이용가능한 정보 및 자료가 부족한 상황에서 과학적이고 체계적인 자원관리방안을 도출하기 위하여 잠재어획가능량 산정의 5단계 체계를 구축하였다. 섬진강 일본재첩의 잠재어획 가능량은 보다 높은 정보수준을 요구하는 1-2단계에서 산정하였다. 이에 섬진강 일본재첩의 잠재어획가능량은 상업어획조사에 의한 1단계 정보수준에서는 77.66 톤, 직접자원조사에 의한 2단계 정보수준에서는 129.82 톤으로 추정되었다.