• Journal of Electrical Engineering and Technology
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• 제3권3호
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• pp.363-372
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• 2008

In this paper, knowledge-based approach using Support Vector Machines (SVMs) are used for estimating the coordinated zonal settings of a distance relay. The approach depends on the detailed simulation studies of apparent impedance loci as seen by distance relay during disturbance, considering various operating conditions including fault resistance. In a distance relay, the impedance loci given at the relay location is obtained from extensive transient stability studies. SVMs are used as a pattern classifier for obtaining distance relay co-ordination. The scheme utilizes the apparent impedance values observed during a fault as inputs. An improved performance with the use of SVMs, keeping the reach when faced with different fault conditions as well as system power flow changes, are illustrated with an equivalent 265 bus system of a practical Indian Western Grid.

• 한국응용곤충학회지
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• 제22권2호
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• pp.147-159
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• 1983

In general, herbicides have been classified according to selectivity, mobility. time of application, methods of application, mode of action and chemical property and structure. However, there was no generally accepted classification system for practical use in the field. The primary processes affected by the majority of herbicides are the growth process through cell elongation and/or cell division, the photosynthetic process specifically the light reaction, the oxidative phosphorylation and the integrity of the membrane systems. The usual approach in the study of the mechanism by which herbicides kill or inhibit the growth of plants is to initially determine the morphological phototoxicity systems, The mechanism by which a herbicide kills a plant or suppresses its development is actually the resultant effect of primary and secondary(or side) effects. In most instances, the death of the plant is due to the secondary effects. To induce the desired response, a herbicide must be able to gain entry into the plants and once inside, to be transported within the plant to its site(s) of activity in concentrations great enough. Obstacles to the entry and movement of herbicides in plants are generally classified by leaf and soil obstacles, translocation obstacles and biochemical obstacles, and these obstacles are also strongly influenced by plant species and by environmental factors such as light, temperature, rainfall and relative humidity. And hence, in most instances, results obtained from laboratory or greenhous vary from those of field experiment. Author attempted to classify herbicides from the field experiment using the two-dimensional ordination analysis to obtain practical information for selecting effective herbicides or to choose effective herbicide combinations for increasing herbicidal efficacy or reducing the chemical cost. Based on this two-dimensional diagram, desired herbicides or combinations were selected and further investigated for the interaction effects whether these combinations are synergistic, additive or antagonistic. From the results, it was concluded that these new approach could possibly be give more comprehensive informations about effective use of herbicide than any other systems.

• The Korean Journal of Ecology
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• 제10권2호
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• pp.63-80
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• 1987

Detrended correspondence analysis(DCA) and two way indicator species analysis(TWINSPAN) were applied to Pinus densiflora stands nearby Seoul area in order to classify them into several groups based on herbaceous species and environmental relationships. The eighteen Pinus densiflora stands were perferenially selected, In each stand, 30 to 60 quadrats, (20X20)cm, were randomly estabilished. In each quadrat, all stems for herbaceous plants were recorded by species and their covers were measured. In addition environmental factors such as soil depth, thickness of litter layer, soil compressibility, tree density, basal area, elevation, slope and exposure were detemined for each stand. Four to twelve soil cores were collected and physical and KDICical properties were determined. This survey was conducted form 15, July, 1985 to 22, September, 1985. Analysis of the vegetation and environmental data were performed with DECORANA and TWINSPAN. Stand ordination (DECORANA) and classification (TWINSPAN) based on herbaceous species suggest that the stands can be classified into five groups in terms of herbaceous species composition and environmental relationships. Type I, Type II, Type III, Type IV and Type V were classified to SUBMESIC-CLO-SED-CANOPY (Artemisia keiskeana, Carex nanella), MESIC-CLOSED CANOPY (Spodiopogon sibiricus, Miscanthus sinensis, Carex nanella, Pteridum aquilinum, Melampyrum rosium), SUBMESIC-OPEN CANOPY (Carex nanella, Spodiopogon sibiricus, Miscanthus sinensis), XERIC-CLOSED CANOPY (Carex nanella, Spodiopogon sibiricus, Carex nanella), and XERIC-OPEN CANOPY (Arundinella hirts, Spodiopogon sibiricus, Carex nanella), respectively. These results were consitent with environmental trends on stan ordination. Application of the ordination and classifiaction to Pinus densiflora stands were effective as a approach on obtaining perliminary ecological information.

• Journal of Ecology and Environment
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• 제34권4호
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• pp.347-355
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• 2011

Effects of forest thinning on community level properties have not been understood yet in Korea. We investigated regeneration patterns and trajectories after a disturbance by applying a chronosequence approach. Light availability, litter and woody debris cover, and species composition were determined for twenty 50 m line-transect samples representing a disturbance duration gradient (within 11 years). Environmental factors such as light availability and coverage of woody debris and litter changed abruptly after thinning and then returned to the pre-disturbance state. Although species richness was gained at shrub and ground layer in a limited way in both forests, cover of various functional types revealed diversity in their responses. Notably, Alnus firma stands exhibited a larger increment of cover in woody plants. Ordination analysis revealed different regeneration trajectories between natural and planted stands. Based on ordination analysis, rehabilitated stands showed movement to alternative states compared with natural ones, reflecting lower resilience to perturbation (i.e., lower stability). Our results suggest that community resilience to artificial thinning depends on properties of the dominant species. But to get more explanatory ecological information, longer-term static observations are required.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.340-343
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• 2001

In an electrical network, electrical power are transmitted by a various of protection, isolation and control electric circuit devices. This thesis deals with the protection function between circuit-breakers. The protective coordination concerns the behaviour of two devices placed in series in an electrical network, with a short-circuit downstream circuit-breaker. It has two basic principles: First, discrimination which is an increasing requirement of low voltage electrical distribution systems. Second, which is less well known: cascading, which consists of installing a device, whose breaking capacity is less than the three-phase short-circuit current at its terminals and helped by main circuit-breaker. The important advantage of cascading is to be able to install at a branch circuit-breaker of a lesser performance without endangering the safety of the installation for more economical usage. To determine and guarantee co-ordination between two circuit breakers, it is necessary to carry out a theoretical approach, first, and then confirm the results by means of standard tests. This is illustrated in appendix A of IEC 947-2.

• 한국작물학회지
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• 제34권1호
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• pp.74-80
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• 1989

우리나라에 재배되고 있는 주요 수도품종들의 생육형질들의 차이점을 양적으로 나타내고 또한 이들 품종들의 위치를 도면상에 나타내어 실용적인 면에서 품종을 쉽게 선정 또는 분류할 수 있게 하기 위해 Two-dimensional ordination 분석법을 도입하여 검토 분석하였던 결과를 요약하면 다음과 같다. 1. 공시된 27개 품종중에서 장성벼가 다른 품종들과의 종합적인 생육형질의 유사성계수가 가장 적었으며, 다음으로는 칠성벼, 가야벼, 기호벼, 한강찰벼, 상풍벼 순이었고, 반대로 종합성육형질의 유사성계수가 가장 높은 품종은 대청벼와 영산벼였고 다음은 낙동벼, 신선찰벼, 광명벼, 영덕벼, 팔공벼, 동진벼의 순이었다. 2. 품종집단별로 유사성계수가 가장 적은 품종집단은 가야벼와 상풍벼, 기호벼 또는 서남벼집단, 삼강벼, 기호벼집단, 칠성벼와 장성벼, 상풍벼, 추정벼, 기호벼 또는 서남벼집단, 장성벼와 광명벼, 상풍벼, 기호벼, 대창벼 또는 화성벼집단으로 45∼50％ 범위의 유사성계수를 보였다. 한편 유사성계수가 가장 큰 품종집단은 동진벼와 신선찰벼, 대청벼, 섬진벼 또는 영산벼집단, 상풍벼와 기호변집단, 영덕벼와 영산벼 또는 팔공벼집단, 광명벼와 영덕벼집단, 락동벼와 광명벼, 영덕벼, 대청벼, 화성벼 또는 영산벼집단, 신선찰벼와 대청벼 또는 영산벼집단, 섬진벼와 대청벼 또는 영산벼집단. 대청벼와 영산벼집단으로서 유사성계수가 85％ 이상을 나타내었다. 3. Two-dimensional ordination 분석법에 의한 품종분포는 대부분의 품종이 현행 분류방법인 통일형과 자포니카형으로 구분되었으나, 통일형품질인 중원벼는 오히려 자포니카형 품종군에, 그리고 자포니카형 품종인 섬진벼는 오히려 통일형 품종군에 위치하였고, 신선찰벼와 대청벼는 통일형과 자포니카형 품종군의 중앙부에 위치하였다. 4. Two-dimensional ordination 분석법에 의한 품종분류는 품종배치다양화를 위한 실용적인 선정방법이 될 뿐만 아니라 목적하는 바, 형질을 갖는 품종선정에도 좋은 정보를 제공하여 주었다.

• 농촌지도와개발
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• 제21권2호
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• pp.211-254
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• 2014

말라위 농촌지도사업은 최근 농업개발에서의 부족한 기여와 소농의 요구에 부응하지 못한 측면에서 많은 비판을 받고 있다. 그럼에도 불구하고 농촌지도사업은 농촌생활과 농촌빈곤 문제 개선을 위해서 중시되고 있다. 말라위 농촌지도사업은 공공부문과 민간부문에서 많은 도전을 받고 있다. 이러한 도전에 분명하고 적극적인 대응은 모든 농가들에게 편익을 제공하고 정부정책 목적을 달성하기 위한 농촌지도사업의 미래의 모습을 만드는 데 있어서 매우 중요하다. 말라위 농촌지도사업의 당면과제는 민주주의, 시장자유화, 분권화, 에이즈, 공공자원부족, 공공부문개혁, 협력 등이다. 이를 달성하기 위하여 말라위 농촌지도사업은 복합적인 지도사업수요를 제공해야 하고, 식량문제와 빈곤문제해결을 위하여 협력을 촉진해야 한다. 또한 지도사업은 모델빌리지접근법(Model-village approaches)을 기초한 지역농촌지도사업 시스템을 통하여 모든 농가들이 접근할 수 있고 질높은 지도사업 서비스를 추진해야 할 것이다.

• The Korean Journal of Ecology
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• 제12권2호
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• pp.83-108
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• 1989

To discern general tendency in relatively pure even-aged pine stands, to group the stands and to perceive neighbourhood effects a total of 39 sites of pine stand was surveyed from nearby Seoul (12 sites), Chunsung, Kangwon (13 sites) and Sosan, Chungnam (14 sites), for herb and shrub species 32, 19; 37, 19 and 41, 14 in the respective areas from September 1987 to July 1988. In terms of detrended correspondence analysis (DECORANA), the stands were subjected to ordinate with 16 physical variables and the vegetational variables. The resource ratio (N:P, N:K, P:K) as physical variables also was tried out in the DECORANA as well as independent variable (N.P.K). The outcome did not show any meaningful difference. It is suggested that there seems to be no apparent interaction among the elements in the study. Three vertical vegetation componeent, that is, tree layer, shrub layer, herb layer were subjccted to DECORANA independently, pairwisely and as a whole (a total 7 combinations). Of those analysis herb layer trial alone seems to indicate relatively clearer differences among the physical variables. In the stands nearby Seoul first axis indicated soil field capacity and exchangeable cations (K, Ca and Na) and second axis did not show any tendency. For the Chunsung stands first axis also revealed soil field capcity and amount of arganic matter and second axis showed amount of exchangeable cation (K, Ca and Na), In the Seosan 1st axis indicated pH and exchangeable cations (K, Ca and Na). For the 39 sites 4 clusters in terms of herb layer might be defined: Peucedanum terebinthaceum-Cymbopogon tortilis-Polygala japonica-Festuca ovina (1); Atractylodes japonica-Patrina scabiosaefolia (2); Potentilla fragarioides-Atractylodes (3); and Cymbopogon tortilis (4). In the neighbourhood effects study in terms of the basal area distribution, Thiessen polygon area and Gini coefficient for the Pinus thunbergii stands of Seosan the Thiessen polygon area approach seems to indicate earlier (30 years old) neighbourhood effect than the others (45 years).

• 한국환경생태학회지
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• 제33권4호
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• pp.447-452
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• 2019

본 연구는 전국에 분포하고 있는 주요 산채류의 자생지를 대상으로 TWINSPAN에 의해 식생 구조를 파악하고 Ordination DCCA에 의한 군락구조와 환경요인의 상관관계를 분석하여 산채류 재배지 환경조성에 필요한 생태학적 기초자료를 제공하기 위하여 2016~2017년에 수행되었다. 전국 주요 산채류 자생지 91개 조사구에서 각각 초본층에 중요치가 높게 나타난 100분류군을 대상으로 TWINSPAN을 실시한 결과, 고려엉겅퀴군락과 수리취군락, 곰취군락과 원추리군락, 넓은잔대군락, 도라지군락과 참취군락, 두릅나무군락과 고사리군락, 참나물군락과 고비군락으로 구분되었다. TWINSPAN에 의해 분류된 11개 군락과 11개의 환경 요인으로 DCCA ordination 결과, 해발고가 가장 높은 상관관계를 보였고, 고려엉겅퀴군락, 수리취군락 및 곰취군락은 해발고는 높고 경사는 완만하며, 양료에 의한 입지환경이 유사한 지역에 분포하는 것으로 나타났다. 두릅나무군락 및 고비군락은 해발고, pH, O.M, T-N, $Ca^{2+}$ 및 C.E.C가 낮은 입지환경에 분포하였다. 원추리군락은 해발고는 낮고 경사는 중간정도이며, 주로 북동, 북서사면에 pH는 낮고 $P_2O_5$는 약간 높은 입지에 분포하였고, 넓은 잔대군락은 해발고는 약간 높고 경사는 낮은 남동, 남서사면에서 pH는 높고 $P_2O_5$는 낮은 입지에 분포하여 원추리군락과 넓은잔대군락은 입지 환경이 상반되는 경향을 보였다. 도라지군락은 해발고는 낮고, 남서사면에 경사가 완만하며, pH, O.M, T-N, $P_2O_5$, $Ca^{2+}$ 및 C.E.C가 낮은 반면 $Mg^{2+}$는 높은 입지환경에 분포하였다. 고사리군락은 해발고가 낮은 남서사면에 주로 분포하고 O.M, T-N, C.E.C. $P_2O_5$, $Ca^{2+}$ 및 $K^+$가 낮은 곳에 분포하는 것으로 나타났다. 참취군락 및 참나물군락은 본 조사에서 많은 군락을 차지하고 있었으며, 다양한 입지 환경에 분포 하는 것으로 나타났다.

• 국제초고층학회논문집
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• 제1권1호
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• pp.53-59
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• 2012

With the rise in CPU power and the generalization and popularity of computers, engineering practice also changed from hand calculations to 3D computer models, from elastic linear analysis to 3D nonlinear static analysis and 3D nonlinear transient dynamic analysis. Thanks to holistic design approach and current trends in freeform and contemporary architecture, BIM concept is no longer a dream but also a reality. BIM is not just providing a media for better co-ordination but also to shorten the round-the-clock time in updating models to match with other professional disciplines. With the parametric modeling tools, structural information is also linked with BIM system and quickly produces analysis and design results from checking to fabrication. This paper presents a new framework which not just linked the BIM system by means of parametric mean but also create and produce connection FE model and fabrication drawings etc. This framework will facilitate structural engineers to produce well co-ordinate, optimized and safe structures.