• 한국국방경영분석학회지
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• 제8권1호
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• pp.53-70
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• 1982

This thesis develops a more realistic and applicable new set covering model that is adjusted and supplied by the existing set covering models, and induces an algorithm for solving the new set covering model, and applies the new model and the algorithm to an actual set covering problems. The new set covering model introduces a probabilistic covering aistance ($0{\eqslantless}p{\eqslantless}1$)or time($0{\eqslantless}p{\eqslantless}1$) instead of a deterministic covering distance(0 or 1) or time (0 or 1) of the existing set covering model. The existing set covering model has not considered the merit of the overcover of customers. But this new set covering model leads a concept of this overcover to a concept of the parallel system reliability. The algorithm has been programmed on the UNIVAC 9030 for solving large-scale covering problems. An application of the new set covering model is presented in order to determine the locations of the air surveillance radars as a set covering problem for a case-study.

• Journal of applied mathematics & informatics
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• 제28권1_2호
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• pp.1-11
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• 2010

The conditional covering problem is an important variation of well studied set covering problem. In the set covering problem, the problem is to find a minimum cardinality vertex set which will cover all the given demand points. The conditional covering problem asks to find a minimum cardinality vertex set that will cover not only the given demand points but also one another. This problem is NP-complete for general graphs. In this paper, we present an efficient algorithm to solve the conditional covering problem on interval graphs with n vertices which runs in O(n)time.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.1041-1044
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• 1996

The plastic-film-covered hill planter is a new-type seeding machine, including tow types which are mounted by 11kw and 40 kw tractors. It is made up of fertilizing , plastic-film covering perforating film and hole seeding, soil sealing apparatus, and can work at 5-7kw/h. The plastic-film covering and seeding of cotton, corn and soybean can all use this machine. The plastic-film-covered hill planter is mainly composed of plastic film covering unit, drum-type hill-drop unit and furrow coverer, some other types are also equipped with fertilizer drill unit. It can do combined work of covering plastic film , sowing , plastic film perforating , soil covering at one time, and it is suitable to the covering plastic film as well as planting of the grandulated crops, such as cotton , corn, soybean and so on.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.226-226
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• 2017

This study was to evaluate methods to high quality food ramie rice cake, thereby increasing farm income. This study investigated the effects of different covering material on stable winter survival management with edible leaf in Ramie(Boehmeria nivea L.). The method of winter survival with covering material were conducted under three condition compose to Non covering, Rice straw cutting covered with 500kg.10a-1, Rice husks covered with 1,000kg.10a-1(covered 4~5 cm thickness in the soil surface). Method of application were standard application(N-P-K-Compost applied at 27-9-27-600kg.10a-1. Compost and fused phosphate applied at 100% of basal fertilizer in March 25. 20% of top dressing were four times application in March 25 - October 5. Planting year were March 15, 2011. Plants were spaced 60 cm apart in rows 25 cm apart with open cultivation. According to non covering < Rice husks covered with 1,000kg.10a-1 < Rice straw cutting covered with 500kg.10a-1 cultivation this order, aerial part as a result were plenty amount of growth. Sprout time and winter survival rates was uncovering control plot compared to 2 - 5 days quickly, 45-57% highly by rice husks and rice straw covering. Green leaf yields is untreated control plot (12,44 kg.10a-1) compared to rice husks covering 7% higher, and rice straw covering increased to 18% of the most.

• 한국컴퓨터정보학회논문지
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• 제20권9호
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• pp.21-29
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• 2015

The set partitioning problem is a well-known NP-hard combinatorial optimization problem, and it is formulated as an integer programming model. This paper proposes an Integer Programming-based Local Search for solving the set partitioning problem. The key point is to solve the set partitioning problem as the set covering problem. First, an initial solution is generated by a simple heuristic for the set covering problem, and then the solution is set as the current solution. Next, the following process is repeated. The original set covering problem is reduced based on the current solution, and the reduced problem is solved by Integer Programming which includes a specific element in the objective function to derive the solution for the set partitioning problem. Experimental results on a set of OR-Library instances show that the proposed algorithm outperforms pure integer programming as well as the existing heuristic algorithms both in solution quality and time.

• 한국건축시공학회지
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• 제3권4호
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• pp.129-134
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• 2003

The purpose of this study is to evaluate efficiency by the Life Cycle Cost(LCC) analysis of floor covering materials for remodeling. This study has been performed as a case study. The LCC analysis is a technique which takes account into both initial-future costs and benefits of an investment over some period of time. LCC is important in commercial decision making because it provides improved assessment of the living-term cost effectiveness of construction projects as well as alternative economic methods that focus on initial costs. For LCC analysis and comparison, the present value technique is used. The results of this study are summarized as follows; (1) A LCC analysis model of floor covering materials is suggested through a case study (2) As a result of LCC case study, the type of sheet is analysed more economical than that of tile in floor covering materials.

• 생물환경조절학회지
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• 제11권4호
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• pp.175-180
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• 2002

본 시험은 봄철 노지재배시 막덮기 피복자재가 녹색꽃양배추의 생육 및 수량에 미치는 영향을 구명코자 수행하였다. 막덮기와 유공필름처리에서 무처리에 비하여 3~4$^{\circ}C$의 기온상승 및 2~3$^{\circ}C$지온 상승효과를 보였으며 상대습도에 있어서도 높게 유지되었다. 막덮기와 유공필름처리에서 생체중, 근중 등 생육이 크게 향상되었다. 이상화뢰의 발생은 막덮기 피복처리에서 가장 적었다. 출뢰일은 38~40일로 처리간 큰 차이가 없었으나, 화뢰중은 막덮기 피복과 유공필름처리에서 400g이상으로 무처리에 비하여 2배 이상 증가되었다. 첫 수확일은 막덮기 처리에서 무처리에 비하여 2주 이상 빨라 조기수확이 가능하였다 상품수량에서도 막덮기와 유공필름처리에서 1,600kg/10a이상으로 많았으며 다음이 P.E. 무처리순으로 무처리에서 857kg으로 가장 적었다. 250g 이상의 화뢰중 비율도 막덮기 처리에서 고르게 분포되었다. 이처럼 봄철 막덮기 자재를 이용한 녹색꽃양배추 재배시 조기수확과 증수는 물론 품질향상을 기할 수 있었다

• Structural Engineering and Mechanics
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• 제54권5호
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• pp.955-971
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• 2015

In this paper, the influence of the polled direction of piezoelectric materials on the stress distribution is studied under time-harmonic dynamical load (time-harmonic Lamb's problem). The system considered in this study consists of piezoelectric covering layer and piezoelectric half-plane, and the harmonic dynamical load acts on the free face of the covering layer. The investigations are carried out by utilizing the exact equations of motion and relations of the linear theory of electro-elasticity. The plane-strain state is considered. It is assumed that the perfect contact conditions between the covering layer and half-plane are satisfied. The boundary value problems under consideration are solved by employing Fourier exponential transformation techniques with respect to coordinates directed along the interface line. Numerical results on the influence of the polled direction of the piezoelectric materials such as PZT-5A, PZT-5H, PZT-4 and PZT-7A on the normal stresses, shear stresses and electric potential acting on the interface plane are presented and discussed. As a result of the analyses, it is established that the polled directions of the piezoelectric materials play an important role on the values of the studied stresses and electric potential.

• 한국실내디자인학회논문집
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• 제23권3호
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• pp.29-38
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• 2014

This paper is to analysis covering and exposing elements through surface in the spirit of the time through the meaning of relationship between structure and symbol(ornament) in the theory of dressing of Gottfrid Semper. In other words, The purpose is to illuminate how complementary tectonic between structure and symbolic of an architecture surface is expressed in accordance with the biased required conditions relating with the paradigm of the era. The advancement of the new method of tectonic and the new aesthetic taste have a deep relation with the reconsidering the dichotomy classification discussing a dominant position between structure and symbol(ornament). Expression of surface representing the era comes across the combined interpretation of technology, structure, and the non-physical culture's art of the community and the era.

• 한국ITS학회 논문지
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• 제12권1호
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• pp.43-50
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• 2013

본 연구는 사고처리 지연으로 인한 피해를 최소화할 수 있는 고속도로 순찰대의 최적입지를 결정하는 것을 목적으로 한다. 이를 위하여 우리는 최단거리를 기준으로 서비스 관할구간을 할당하는 maximum covering 문제와 사고 빈도 가중 p-center 문제를 각각 구성하고, 두 문제를 해결하기 위하여 라그랑지안 완화 알고리즘과 Daskin의 휴리스틱 알고리즘을 적용한다. 제안된 모형들의 결과는 한국 고속도로의 사고자료를 기반으로 최대사고가중거리, 평균사고가중거리, 평균처리거리 등의 사고처리 서비스 수준 지표를 이용하여 현재의 순찰대 입지와 비교된다. 비교 결과를 통해 제안된 모형들은 10km 평균 접근거리와 약 10분의 평균 접근시간을 개선할 수 있음이 확인된다. 또한 현재의 입지를 고정시키고 서비스 관할구간만을 변경할 경우에도 서비스 수준이 개선될 수 있다. 본 연구에서 제시된 모형과 결과는 고속도로 사고처리 서비스 수준을 개선하는 데에 활용될 수 있으며, 또한 다양한 유형의 긴급시설 입지 결정이나 시간대별 사고자료에 기초한 유동적 관할구역 설정 등의 이론적 기반을 제공할 수 있을 것으로 사료된다.