• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.335-341
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• 2000

In this study, the multiobjective linear programming (MOLP) formulation was built to solve for the optimal forest management planning considering carbon sequestration and timber production simultaneously. The formulation was applied to a case study problem to investigate the trends of the optimal forest harvest schedules as the function of preference of forest management for carbon sequestration and timber production. The study site was Mt. Kari area in Hongchun. The formulation includes several site-specific constraints for non-declining yields, upper and lower bounds of cut volume and area for timber, ending inventory conditions, etc.. According to the changes of weight combinations for timber production and carbon sequestration, the joint production possibilities curve was proposed as the option for management choice.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1507-1511
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• 2005

지금까지 우리나라에서는 60년대 이후 5차례의 수자원계획이 수립되었으나, 그동안 시민단체 등을 중심으로 장래 물 수요 추정과 물 부족량 등에 대해 꾸준한 문제제기가 있어왔다. 이러한 문제제기는 물 수요량 및 물 부족량 산출과정에 대한 불신으로부터 나타난 결과라고 볼 수 있다. 따라서 이러한 문제들은 수자원 계획 수립과정에서 대중과 이해관계자들의 참여를 보장함으로써 해결될 수 있으며, 이를 위해서는 이러한 과정을 지원할 수 있는 적절한 계획 수립 도구가 선택되어야 한다. K-WEAP은 장기적인 수자원 계획에 적합한 모형으로 수자원 수급 네트워크를 기반으로 선형계획법(Linear Programming)을 이용하여 하도 물 수지를 수행하며, 통합적이고 종합적인 계획 수립 구조와 뛰어난 시나리오 분석 기능을 제공한다. 또한 용수수요와 공급관련 정보들을 관리할 수 있는 데이터베이스로서의 역할을 수행할 수 있어 계획 수립 과정에서 이용된 자료에 대한 공유가 가능하다는 장점이 있는 모형이다. 본 연구에서는 이와 같은 특성을 갖는 수자원 계획 수립도구인 K-WEAP 모형이 국가 수자원 계획을 수립하는 과정에서 어떻게 적용되고 있는 지를 알아보고, 우리나라 4대강 권역에 대한 물 수지 네트워크를 K-WEAP을 이용하여 구축하였으며, 과거 수자원 계획 수립에서 이용된 방법들과의 비교 검토를 수행하였다.

• Environmental and Resource Economics Review
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• v.15 no.3
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• pp.405-423
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• 2006

This paper develops theoretical model between economic growth and pollution as follows: First, emissions are generated from final good production process and technology accumulation. Second, pollution is directly connected with increase in final good production or in consumption, Third, no pollution abatement activity would be undertaken. Fourth, reproducible factors associated with labor and capital input are used in production function. We also test the existence of nonlinear Dynamics between economic growth and pollution using an exponential smooth transition autoregressive model(ESTAR). We find the presence of nonlinear dynamics between economic growth and pollution with a time series data for Seoul. This result shows indirectly that an inverted U relationship between air pollution and economic growth exists.

• The Korean Journal of Applied Statistics
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• v.35 no.2
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• pp.229-250
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• 2022

Since the publication of Markowitz's (1952) mean-variance portfolio model, research on portfolio optimization has been conducted in many fields. The existing mean-variance portfolio model forms a nonlinear convex problem. Applying Dantzig's linear programming method, it was converted to a linear form, which can effectively reduce the algorithm computation time. In this paper, we proposed a Dantzig perturbation portfolio model that can reduce management costs and transaction costs by constructing a portfolio with stable and small (sparse) assets. The average return and risk were adjusted according to the purpose by applying a perturbation method in which a certain part is invested in the existing benchmark and the rest is invested in the assets proposed as a portfolio optimization model. For a covariance estimation, we proposed a Gaussian kernel weight covariance that considers time-dependent weights by reflecting time-series data characteristics. The performance of the proposed model was evaluated by comparing it with the benchmark portfolio with 5 real data sets. Empirical results show that the proposed portfolios provide higher expected returns or lower risks than the benchmark. Further, sparse and stable asset selection was obtained in the proposed portfolios.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.3
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• pp.71-79
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• 1993

Dynamic production planning problems are to determine the optimal production times and production quantities of product for discrete finite periods. In previous many researches, the solutions for these problems have been developed through the algorithms using dynamic programming. The purpose of this research is to suggest the new algorithm using linear programming. This research is to determine optimal production quantities of product in each period to satisfy dynamic for discrete finite periods, minimizing the total of production cost and inventory holding cost. Cost functions are concave, and no backlogging for product is allowed. The new algorithm for capacity constrained problem is developed.

• Korea journal of population studies
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• v.32 no.2
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• pp.59-85
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• 2009

본 연구는 최근 인구학에서 공간적 접근을 시도하는 논의들이 활발해지는 경향과 함께 지역 적합적 저출산 대응정책의 필요성의 대두라는 정책적 수요에 부합하고자 자녀출산계획에 있어 지역의 공간적 효과가 미치는 효과를 분석하였다. 또한, 기혼여성의 연령, 출산한 자녀의 수가 자녀를 출산할 계획을 가질 확률에 대한 비선형적 효과를 실증적으로 분석하였다. 다층모형과 같이 최근 지역연구에서 이용되고 있는 실증분석방법들의 한계점을 살펴보고, 그 대안으로 Geo-Additive Model을 적용하였다. 동 방법론은 한 모형 내에서 공간의 구조적 효과와 비구조적 효과, 연속형 변인의 비선형효과 등을 동시에 추정할 수 있다. 이를 위한 분석자료로 통계청의 2005년도 인구주택총조사의 마이크로데이터 중 2% B형 자료를 이용하였다. 분석결과 기혼여성이 자녀를 출산할 계획을 가질 확률에 기혼여성의 연령과 출산한 자녀의 수는 비선형적 효과를 주었으며, 특히 각 개인들은 현재의 출산 상태에서 자녀 한명을 추가로 출산하는 것이 동일한 부담으로 작용하지 않음을 알 수 있었다. 이를 통해 기혼여성들의 첫출산 시점이 결혼연령에 따라 차이가 있고 결혼코호트에 따라 다르더라도 첫출산 자체가 여전히 보편적인 현상이라는 가정을 받아들인다면, 출산율 제고를 위한 정책의 대상은 첫째아를 이미 출산한 여성들이 되어야 할 것으로 보인다. 또한, 자녀를 출산할 계획을 가질 확률에 지역의 구조적 공간효과가 유의미한 영향을 주는 것으로 분석되었다. 지역별 합계출산율의 공간 자기상관분석 결과와 비교해 본 결과 출산계획의 구조적 공간효과가 양의 효과를 미치는 지역에서는 실제 출산행위인 합계출산율도 높지만, 구조적 공간효과가 부적인 효과를 가지고 있는 지역에서는 합계출산율도 낮게 나타남을 알 수 있었다. 따라서 각 지방자치단체에서는 지자체들의 정책수요나 자원 및 재정의 부담능력 등 지역별 차이를 고려하지 않은 일률적인 정책의 추진을 지양하고, 지역 특수성을 고려하여 지역에 적합한 출산정책을 추진해야 할 것이다.

• Water for future
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• v.23 no.1
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• pp.109-118
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• 1990

In this study, the effectiveness of existing streamflow data collection networks in the Han and the Nakdong River Basin is evaluated for various gaging plans of 5, 10, 15 and 20years planning horizons by the nonlinear integer programming method, and also a technique for adjustment and planning of the existing network is provided for the purpose of increasing the efficiency of the network in terms of ecomony. The objective function is minimization of the average sampling mean square error of regional regression model with regression parameters estimated by generalized least squares method.

• Journal of the Korean Data and Information Science Society
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• v.25 no.4
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• pp.697-703
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• 2014

Deal-or-No-Deal game is a famous TV show program of NBC, USA, which is composed of 10 stages at most. At each stage from the first and the ninth, a banker suggests a deal price to participants. In this paper, we intend to reveal the banker's deal price model using a constrained linear model and quadratic program. As results, we provide a linear model in relation to the deal price at each stage and then show using simulation data that the deal price is equal to the nearest integer of the value to be obtained by the provided linear model.

• Information Systems Review
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• v.5 no.2
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• pp.203-217
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• 2003

Constraint Programming and Optimization have developed in different fields to solve common problems in real world. In particular, constraint propagation and linear Programming are their own fundamental and complementary techniques with the potential for integration to benefit each other. This intersection has evoked the efforts to combine both for a solution method to combinatorial optimization problems. Attempts to combine them have mainly focused on incorporating either technique into the framework of the other with traditional models left intact. This paper argues that integrating both techniques into an old modeling fame loses advantages from another and the integration should be molded in a new framework to be able to exploit advantages from both. The paper propose a declarative modeling framework in which the structure of the constraints indicates how constraint programming and optimization solvers can interact to solve problems.

• ETRI Journal
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• v.6 no.3
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• pp.3-8
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• 1984

Telecommunication equipment is very obsolescent product from commercial point of view and its industry is large scale as well as its inter-industrial linkage effect is enormous. Therefore investment in it should be carefully carried out. However decision making on this problem is very difficult because the environment of investment is too much complex with multiple objectives. Goal-programmed Investment Model in Telecommunication Equipment is discussed in this study to solve the above problem. The effectiveness and workability of this model is verified by Telephone Exchange Case through computer program.