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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Operations Research and Management Science Society
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Journal DOI :
The Korean Operations and Management Science Society
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Volume & Issues
Volume 38, Issue 4 - Dec 2013
Volume 38, Issue 3 - Sep 2013
Volume 38, Issue 2 - Jun 2013
Volume 38, Issue 1 - Mar 2013
Selecting the target year
Evolution and Development Process of Customer Value Research Using Network Analysis In Marketing : Focusing on SSCI Rank 20 Journals Using Author Co-Citation Analysis
Yoo, Kyungok ; Kim, Hyang Mi ; Kim, Jae Wook ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 1~24
DOI : 10.7737/JKORMS.2013.38.2.001
The research about customer value has developed over the past years in the marketing field. On the other hand, the stream of the idea has not fully been structured yet. It is the purpose of this research to present the process of development together with the intellectual structure in the field of customer value researches using "Author Co-citation Analysis" (ACA). For the purpose of the research, authors chosen were ranked in order of frequency according to their citations which were used for network analysis. Further, it was of advantage in finding the development process for this research from 1996 to 2011. The trend were set into three time-line groups/trends (1996~2000, 2001~2005, and 2006~2011) that were respectively analyzed. In conclusion, the research represents the intellectual structure of customer value in each period. The research having been tried, influenced a variable field in other marketing researches. While still, many researches limit their focus on a "one-way customer value, used by companies in the past and some in the present, many researches now have a wider perspective about the value and relationship of their customer and their company, together with the society at large.
Project Time-Cost Tradeoff Problem with Milestones under an Uncertain Processing Time
Choi, Byung-Cheon ; Chung, Jibok ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 25~42
DOI : 10.7737/JKORMS.2013.38.2.025
We consider a project time-cost tradeoff problem with two milestones, where one of the jobs has an uncertain processing time. Unless each milestone is completed on time, some penalty cost may be imposed. However, the penalty costs can be avoided by compressing the processing times of some jobs, which requires additional resources or costs. The objective is to minimize the expected total costs subject to the constraint on the expected project completion time. We show that the problem can be solved in polynomial time if the precedence graph of a project is a chain.
Production and Remanufacturing Planning under Uncertain Supply of Recovery Cores and a Disassemble-to-order Environment
Kang, Changmuk ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 43~63
DOI : 10.7737/JKORMS.2013.38.2.043
Remanufacturing is a process of recovering end-of-life products into serviceable parts for producing new products. Due to the limited supply of recovery cores to remanufacture, a remanufacturing firm also needs to produce or procure new parts for fulfilling the demand. This paper is targeted for solving the problem of determining the optimal amount of newly produced and remanufacturing parts, which is called production and remanufacturing planning (PRP) problem, under uncertain supply of recovery cores. The new production mitigates the risk of insufficient core supply while it takes more costs than the remanufacturing. The PRP model in this paper also considers disassemble-to-order (DTO) environment, in which multiple kinds of parts are remanufactured from multiple products on order of the parts. Whereas existing studies presents only heuristic solutions for DTO remanufacturing, this paper provides an exact solution for this problem and analytical sensitivity of the involved cost parameters, adopting multi-dimensional newsvendor modeling and stochastic linear programming techniques. The result shows that production and remanufacturing plans for multiple products are mutually dependent, and a change of cost parameters involved in only one part is propagated to all other parts.
Applying Bootstrap to Time Series Data Having Trend
Park, Jinsoo ; Kim, Yun Bae ; Song, Kiburm ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 65~73
DOI : 10.7737/JKORMS.2013.38.2.065
In the simulation output analysis, bootstrap method is an applicable resampling technique to insufficient data which are not significant statistically. The moving block bootstrap, the stationary bootstrap, and the threshold bootstrap are typical bootstrap methods to be used for autocorrelated time series data. They are nonparametric methods for stationary time series data, which correctly describe the original data. In the simulation output analysis, however, we may not use them because of the non-stationarity in the data set caused by the trend such as increasing or decreasing. In these cases, we can get rid of the trend by differencing the data, which guarantees the stationarity. We can get the bootstrapped data from the differenced stationary data. Taking a reverse transform to the bootstrapped data, finally, we get the pseudo-samples for the original data. In this paper, we introduce the applicability of bootstrap methods to the time series data having trend, and then verify it through the statistical analyses.
Developing an Investment Framework based on Markowitz's Portfolio Selection Model Integrated with EWMA : Case Study in Korea under Global Financial Crisis
Park, Kyungchan ; Jung, Jongbin ; Kim, Seongmoon ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 75~93
DOI : 10.7737/JKORMS.2013.38.2.075
In applying Markowitz's portfolio selection model to the stock market, we developed a comprehensive investment decision-making framework including key inputs for portfolio theory (i.e., individual stocks' expected rate of return and covariance) and minimum required expected return. For estimating the key inputs of our decision-making framework, we utilized an exponentially weighted moving average (EWMA) which places more emphasis on recent data than the conventional simple moving average (SMA). We empirically analyzed the investment results of the decision-making framework with the same 15 stocks in Samsung Group Funds found in the Korean stock market between 2007 and 2011. This five-year investment horizon is marked by global financial crises including the U.S. subprime mortgage crisis, the collapse of Lehman Brothers, and the European sovereign-debt crisis. We measure portfolio performance in terms of rate of return, standard deviation of returns, and Sharpe ratio. Results are compared with the following benchmarks : 1) KOSPI, 2) Samsung Group Funds, 3) Talmudic portfolio based on the na
ve 1/N rule, and 4) Markowitz's model with SMA. We performed sensitivity analyses on all the input parameters that are necessary for designing an investment decision-making framework : smoothing constant for EWMA, minimum required expected return for the portfolio, and portfolio rebalancing period. In conclusion, appropriate use of the comprehensive investment decision-making framework based on the Markowitz's model integrated with EWMA proves to achieve outstanding performance compared to the benchmarks.
Improving a Risk-Averse Price-Fluctuating Inventory Model by Reallocating Initial Inventories
Park, Chan-Kyoo ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 95~115
DOI : 10.7737/JKORMS.2013.38.2.095
In traditional inventory models, purchase prices of raw materials are assumed to be fixed and have no effect on the optimal choice of inventory policies. However, when purchase prices fluctuate continuously over time, inventory costs are heavily affected by purchasing prices. Risk-averse inventory model decides order quantity and ordering time by considering not just purchase prices but also the risk from the discrepancy between estimated prices and realized prices. In this paper, we propose a myopic inventory policy which incorporates price risk into deciding ordering time and quantities. While the existing risk-averse model has no mechanism to reallocate inventories already purchased for a specific future period, the revised one reallocates initial inventories of each period to other future periods so that it can avoid purchasing raw materials at high prices. Experimental results demonstrate that the revised model outperforms the existing one in respect of total cost and variability.
Factors Influencing the Use Intention of Social Commerce : Focusing on the Moderating Effects of Gender
Kang, Hyunmo ; Kim, Ji-Hern ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 117~139
DOI : 10.7737/JKORMS.2013.38.2.117
Due to the recent development of SNS(Social Network Service) which is represented by Twitter and Facebook, social commerce market which combines on-line shopping mall and SNS is expanding. With increasing speed of its market, this study is to focus on detecting the crucial variables promoting the use intention, which results in the sustainable competitive advantage in social commerce market. This research empirically analyzed the use intention of social commerce. Also, this study explores the moderating effects of gender in explaining intention to use social commerce. A technology acceptance model is applied for pinpointing the antecedents of intention to use social commerce and for revealing cross-gender differences. The results from a survey of 452 participants reveal that the effects of perceived risk, perceived usefulness, ease for use and subjective norm on intentions to use social commerce differ across gender. Findings imply that the risk-free quality and portrayal of in-group or out-group situations of social commerce need to be communicated to female consumers, along with the social norms of using social commerce. When targeting male consumers, the technological features illustrating the usefulness of social commerce should be focused. This study will provide diverse implications companies providing social commerce services.
An Algorithm for Resource-Unconstrained Earliness-Tardiness Problem with Partial Precedences
Ha, Byung-Hyun ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 141~157
DOI : 10.7737/JKORMS.2013.38.2.141
In this paper, we consider the minimization of the total weighted earliness-tardiness penalty of jobs, regarding the partial precedences between jobs. We present an optimal scheduling algorithm in O(n(n+m log m)) where n is the number of jobs and m is the number of partial precedences. In the algorithm, the optimal schedule is constructed iteratively by considering each group of contiguous jobs as a block that is represented by a tree.
Servitization Investment Decisions and a Dynamic Stability Analysis Based on a Two-Sided Market Model
Ju, Hientaek ; Rhim, Hosun ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 159~178
DOI : 10.7737/JKORMS.2013.38.2.159
We present a model, combining servitization decision and a conventional two-sided market approaches, to understand expected outcomes and current market situations. We suppose an individual manufacturer participates in multiple platforms and decides whether to initiate servitization by considering latent profitability and risk. The analytical results from the model show that increasing competition within servitized companies lead to a servitization equilibrium, wherein the ratio of servitized companies in a market is stable, due to a gradual decline in relative benefits compared to non-servitized companies. This holds even in the case that the number of customer is increasing along the diffusion of servitization, under some restricted conditions.
How is the Compensation Structure of Family Firms Different from that of Non-Family Firms? : Evidence from Korea
Yoo, Jungmin ; Yoon, Dae-Hee ;
Journal of the Korean Operations Research and Management Science Society, volume 38, issue 2, 2013, Pages 179~196
DOI : 10.7737/JKORMS.2013.38.2.179
This paper examines the difference in compensation structure between family firms and non-family firms in Korea. A manager's compensation is an important means of motivating a manager to make decisions for shareholders by mitigating conflicts of interest between them. However, the role of a manager's compensation can be weakened in family firms for the following reasons. First, a family member manager has fewer conflicts of interest, compared to a non-family member manager. Second, a family member manager has an intrinsic incentive to increase a firm's value (i.e., family wealth). Finally, a family member manager can monitor non-family member managers more effectively. For the reasons, the agency problem will be less severe in family firms and subsequently the role of compensation will be reduced. The empirical results show that pay-performance sensitivity is smaller in family firms than in non-family firms. The main result is robust to variations such as changes in family ownership, the definition of a family firm, and control variables. Furthermore, this paper compares the pay-performance sensitivity of Chaebol family firms with that of other firms. The result shows that the sensitivity is higher for Chaebol family firms, compared to that in other family firms and non-family firms.