• Management Science and Financial Engineering
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• 제19권2호
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• pp.19-29
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• 2013

Refuse collection network design, one of major decision problems in reverse logistics, is the problem of locating collection points and allocating refuses at demand points to the opened collection points. As an extension of the previous models, we consider capacity and maximum allowable distance constraints at each collection point. In particular, the maximum allowable distance constraint is additionally considered to avoid the impractical solutions in which collection points are located too closely. Also, the additional distance constraint represents the physical distance limit between collection and demand points. The objective is to minimize the sum of fixed costs to open collection points and variable costs to transport refuses from demand to collection points. After formulating the problem as an integer programming model, we suggest an optimal branch and bound algorithm that generates all feasible solutions by a simultaneous location and allocation method and curtails the dominated ones using the lower bounds developed using the relaxation technique. Also, due to the limited applications of the optimal algorithm, we suggest two heuristics. To test the performances of the algorithms, computational experiments were done on a number of test instances, and the results are reported.

• 유통과학연구
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• 제14권2호
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• pp.13-22
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• 2016

Purpose - We examine the marginal value of cash in Korean retail firms, largely unexamined in literature. The marginal value of cash plays pivotal role in cash management policy; especially, a significantly low marginal cash value indicates substantial manager-shareholder conflicts. Research design, data, and methodology - We estimate marginal cash values by adopting the approach of Faulkender & Wang (2006). The sample of retail firms traded in Korean Stock Exchange from 1991 to 2013 is analyzed. Results - We estimate the marginal value of cash for the retail firms as 0.75, implying significant manager-shareholder conflicts. We find a lower marginal value of cash for financially constrained retail firms, contradicting existing theories. The marginal value of cash increases substantially after 2000s, suggesting severe agency conflicts in 1990s as a key reason behind our findings. Conclusions - Our findings support the substantial resource diversion problem in Korean firms and the agency theory of cash management policy. Our results argue against the widely accepted view focusing on implications of financial constraints, which highlights a need of new cash management theory.

• 한국사회복지학
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• 제41권
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• pp.68-92
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• 2000

The purpose of this study is to analyze the determinants of social welfare expenditure in local government. The period of 1995 through 1998 data in Seoul, 6 other metropolitan areas, and 9 provinces (Do) were selected and pooled as unit of analysis and total 8 independent variables were selected based on the theoretical background and previous studies. The pooled cross-sectional time-series regression using SPSS program was adapted for the analysis. Among selected independent variables, the rate of economic expenditure to the local government expenditure, the rate of financial self-reliance, and the increase rate of social welfare expenditure to the previous year has been played a significant role in the rate of social welfare expenditure to the total expenditure. Both the rate of economic expenditure and rate of financial self-reliance have had a negative impacts on the rate of social welfare expenditure and the increase rate of social welfare expenditure have affected the rate of social welfare expenditure positively. Therefore, the variables based on the economic constraint theory as well as incrementalism perspective gives greater explanatory power of the social welfare expenditure than the variables on the political choice theory in Korean local government.

• 한국유통학회지:유통연구
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• 제2권2호
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• pp.107-134
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• 1997

The purpose of this study was to identify perception level of QR and the usage level of QR technologes and to examine the relationships between the firm characteristics and the usage level of QR technologes and QR adoption in domestic fashon industry. Using the usage levels of QR technologes and QR adoption as the dependent variables, the selected firm characteristics, as independent variables, were firm size, perception level of QR benefits, and product characteristics. The findings from the empirical analysis of this study can be summarized as follows : Firm size and perception level of QR benefits were significantly associated with the usage level of QR technologies and adoption. Product characteristics were partly associated with QR adoption. The four elements were partly associated with QR adoption. Most of the QR adopters were using the QR technologies, and will tend to have four elements. From the results of this study, the researcher expects the information from this study to contributes to the body of knowlege about the identification, adoption and utilization of component technologies for QR management systems and draws several counterproposal as follows : The advancement of domestic fashion industry is possible through the systematic adoption of QR by the collaboration of the government & the industry. Most nonadopter had financial problems as a constraint to QR adoption. Financial supports are needed from trade associations and government. The fashion industry may promote the type of smart QR. The type of smart QR means usage level of QR technologies which reflect the firm characteristics and the actual industry state in domestic fashion industry. The fashion industry may establish information technology network (i. e., EDI, POS, EOS) between relative industry such as fiber, apparel manufacturers, retailers. The related industry should make a partnership.

• 국제지역연구
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• 제21권2호
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• pp.143-169
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• 2017

본 논문에서는 1981년부터 2015년까지 거래소에 상장된 비-금융기업을 대상으로 자본구조의 관성이 어떻게 산업 간에 차이가 존재하며 이러한 차이가 상품시장 경쟁에 의해 설명될 수 있는지를 실증검증 한다. 본 논문의 실증분석 결과는 '보다 경쟁적 산업에 속하는 기업일수록 자본구조의사결정에 보다 더 관성적으로 하는 경향이 있다'는 것이다. 이러한 결과는 부채의 규율효과에 의해 설명되며, 상품시장경쟁에 대한 대체재로서 기여한다고 할 수 있다. 상품시장 경쟁이 낮을 때, 경영자는 자본구조의사결정과 관련하여 보다 능동적으로 의사결정을 하며 특히 잉여현금 흐름문제를 제약하기 위하여 부채를 사용한다는 것이다. 더욱이 거래비용이 얼마나 설명력이 있는지를 조사하며 자본구조관성에 대한 일반적인 설명이 되는지 파악한다. 본 논문의 결과는 기업의 자본구조에 관성현상이 존재하지만 미국 기업들만큼은 강하지 않았다. 둘째, 이러한 관성효과는 상품시장경쟁과의 관계를 통하여 강하게 나타나지만, OLS 추정모형에서 관성효과가 사라지는 현상이 나타났다. 이러한 결과는 거래비용이 자본구조의 관성을 설명하는 데 중요한 역할을 하지 않는다는 증거로 해석될 수 있다.

• Management Science and Financial Engineering
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• 제4권2호
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• pp.15-42
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• 1998

A joint problem of order delivery, setup reduction, and cost-sharing in a two-echelon inventory system in which a vendor supplies multiple products to a group of buyers is studied here. The basic premise is that buyers have independently implemented setup reduction programs to acquire benefits from small order sizes. Doing so, however, causes the buyers' individually optimal order cycles to be differ from that of the vendor. In conjunction with this, two models are considered. In the first model, a multi-buyers single product situation is considered in which the vendor implements a joint supply cycle policy. However, buyers, as the dominant party, insist after implementing the individually optimal setup reduction that the vendor accept their individually optimal order schedules. In the second model. a multi-products, single buyer situation is considered in which the buyer implements a joint order policy. Here, the vendor, as the dominant party, refuses to cooperate fully with the buyer's individually reduced joint order schedule, and designs his own individually optimal setup reduction mix for each product under a given budget constraint. This led to a study of an integrated Setup Reduction/Break-even Pricing Policy for each situation to eliminate mismatches in individually optimal cycle times.

• Communications for Statistical Applications and Methods
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• 제15권1호
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• pp.117-124
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• 2008

The liquidity risk is defined as an additional risk in the market due to the timing and size of a trade. A recent work by Cetin et ai. (2003) proposes a rigorous mathematical model incorporating this liquidity risk into the arbitrage pricing theory. A practical problem arising in a real market application is an estimation problem of a liquidity cost. In this paper, we propose to estimate the liquidity cost function in the context of Cetin et al. (2003) using the constrained least square (LS) method, and illustrate it by analyzing the Kellogg company data.

• Management Science and Financial Engineering
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• 제12권1호
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• pp.113-125
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• 2006

Bilevel programming problem is a two-stage optimization problem where the constraint region of the first level problem is implicitly determined by another optimization problem. In this paper we consider the bilevel quadratic/linear fractional programming problem in which the objective function of the first level is quasiconcave, the objective function of the second level is linear fractional and the feasible region is a convex polyhedron. Considering the relationship between feasible solutions to the problem and bases of the coefficient submatrix associated to variables of the second level, an enumerative algorithm is proposed which finds a global optimum to the problem.

• Industrial Engineering and Management Systems
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• 제6권1호
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• pp.83-93
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• 2007

This paper gives an attempt to build a decision support tool linked with a simulation software called ARENA for evaluating and comparing the performance of the push and pull material driven strategies operating in the flow shop environment with a bottleneck resource as the shop's constraint. To be fair for such evaluation, the comparison must be made fairly under the optimal setting of both systems' operating parameters. In this study, an optimal-seeking heuristic algorithm, Genetic Algorithm (GA), is employed to suggest a systems' best design based on the economic consideration, which is the profit generated from the system. Results from the study have revealed interesting outcomes, letting us know the strength and weakness of the push and pull mechanisms as well as the effect of each operating parameter to the overall system's financial performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권8호
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• pp.3243-3256
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• 2020

Recent years have shown a great interest of public in buying and selling of crypto/digital currency. With hundreds of digital currencies in financial market, bitcoin remains the most widely used, adapted, and accepted currency around the world. However, the critics of bitcoin still consider it a threat to modern day power usage. This paper discusses the important pitfalls, pros, and cons related to bitcoin's energy consumption. The paper begins by highlighting the flexibilities cryptocurrency can bring to online money transfers compared to traditional 'fiat' architecture. Then, the focus of the paper entirely remains on listing various facts related to bitcoin's energy utilization including a brief description of several emerging approaches for energy optimization. This paper is concluded by revealing key current challenges associated to bitcoin's energy usage.