• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.2
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• pp.75-93
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• 2013

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$\ddot{i}$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.

• Journal of The Korean Association For Science Education
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• v.29 no.2
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• pp.253-266
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• 2009

This study was focused on analyzing students' informal reasoning patterns and their considerations in decision-making on socioscientific issues. This study involved 20 undergraduate students (10 biology majors and 10 non-biology majors) and showed how the two groups responded on socioscientific issues. Semi-structured interviews were conducted twice respectively based on six scenarios of gene therapy and human cloning. The result showed 93% of the total number of participants' decisions were made by rationalistic reasoning, whereas emotional reasoning was 49%, and intuitive reasoning was 27%. Students usually used two or three informal reasoning patterns together. Most of the students took more consideration on social factors. Some perceived ethical and moral implications of the issues, but they did not consider them seriously. They made their decisions depending on their own values, etc. 65% of the participants got their information on socioscientific issues from the mass media. Biology majors hardly used intuitive reasoning compared to non-biology majors. The Biology major group took into deep considerations on socioscientific issues while the non-biology major group seemed to interpret the given scenarios simply. This implied that the content knowledge was a significant factor of their decision-making. Therefore, it is necessary to develop proper science courses for non-major students to improve their decision-making on socioscientific issues. So, when we develop educational materials or programs, we should consider students' reasoning patterns, their considerations in decision-making, and their content knowledge. And because the mass media has the potential to play a key role for an effective education, we need to make a plan to make a practical application.

• Journal of Family Resource Management and Policy Review
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• v.15 no.4
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• pp.169-188
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• 2011

The primary focus of this study was on the issues associated with family and economic decision-making, in particular for the elderlyhood which might have to (or could be) share the family resources. This study regarded willingness to consider applying for Reverse Mortgage as an economic decision-making. The data was collected by interviewing 320 persons (over age 55) living in metropolitan areas in 2008. We selected 227 cases to find the influence of family, having both spouse and adult-children. We have used a theory of Planned Behavior by Fishbein to analysis three research questions. The results are as follows : first, the results partially explain willingness to consider applying for reverse mortgage using Fishbein's theory. Second, several results indicated that economic decision-makings within the family are influenced by several factors relating to other family member's view. They means that some of Subjective Norm variables, of Attitude Behavior ones, and of Perceived Behavior Control ones. Third, the result shows men and women respond differently to consider to applying for that policy. Men are conscious of the other people, i.e., friends, relatives except close family members, and, on the other hand, women are mindful of close family members, i.e., adult children. Forth, the group who have lower income showed higher intentions to consider that policy, when they have adult-children. Fifth, according to age group, pre-elderly group are influenced by consent of adult-children, a level of education, and on the other hand, elderly group are influenced by the other people, i.e., friends, relatives, a level of education, and so on. These results meaned that these distinct characteristics should be considered to establish Income Security policy for the pre-elderly and the elderly.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.3
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• pp.89-95
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• 2014

The purpose of this study was to examine the impact of a career exploration education to job-seeking anxiety, career maturity and Career decision-making in an effort to prove the effectiveness of career exploration education. The subjects in this study were 65 high school student who were users of B high school in the city of Gwang-Ju. An experimental group and a control group were organized with 65 high school student' each, and a career exploration education was conducted in nine sessions, once a week. The major findings of the study were as follows: The experimental group who participated in the career exploration education felt less job-seeking anxiety, improvement in career maturity and Career decision-making. Second, the experimental group who participated in the career exploration education showed. Third, the experimental group who participated in the career exploration education showed improvement in.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.1
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• pp.42-50
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• 2006

The multi-criteria group decision making (MCGDM) problem is to determine the best compromise solution in a set of competing alternatives that are evaluated under conflicting criteria by decision maker (DM)s. In this paper, we propose a mixed-integer programming (MIP) model to solve MCGDM. The existing method based on minimizing a distance measure such as Median Approach can not guarantee the best compromise solution because the element of median point vector is defined with respect to each criteria separately. However, by considering all criteria simultaneously, we generate median point that is better for locating the best compromise solution. We also utilize the concept of spatial dispersion index (SDI) to produce a threshold value, which is used as a guideline to choose either the Utopian Approach or the Median Approach. And we suggest using CBITP (Convex hull of individual maxima Based Interactive Tchebycheff Procedure) to provide DMs with various Pareto-optimal solutions so that DMs have broad range of selection.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.380-383
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• 2003

In this paper, we propose a fuzzy group decision making method for multiple decision maker-multiple objective programming problems to obtain the agreeable solution. In the proposed method, considering the vague nature of human subjective judgement it is assumed that each of multiple decision makers has a fuzzy goal for each of his/her own objective functions. After eliciting the membership functions from the decision makers for their fuzzy goals, total M-Pareto optimal solution concept is defined in membership spaces in order to deal with multiple decision maker-multiple objective programming problems. For generating a candidate of the agreeable solution which is total M-Pareto optimal, the extended weighted minimax problem is formulated and solved for some weighting vector which is specified by the decision makers in their subjective manner, Given the total M-Pareto optimal solution, each of the derision makers must either be satisfied with the current values of the membership functions, or update his/her weighting vector, However, in general, it seems to be very difficult to find the agreeable solution with which all of the decision makers are satisfied perfectly because of the conflicts between their membership functions. In the proposed method, each of the decision makers is requested to estimate the degree of satisfaction for the candidate of the agreeable solution. Using the estimated values or satisfaction of each of the decision makers, the core concept is desnfied, which is a set of undominated candidates. The interactive algorithm is developed to obtain the agreeable solution which satisfies core conditions.

• Journal of Intelligence and Information Systems
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• v.12 no.3
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• pp.15-32
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• 2006

The increasing complexity of the socio-economic environments makes it less and less possible for single decision-maker to consider all relevant aspects of problem. Therefore, many organizations employ groups in decision making. In this paper, we present a multiperson decision making method using fuzzy logic with linguistic quantifier when each of group members specifies imprecise judgments possibly both on performance evaluations of alternatives with respect to the multiple criteria and on the criteria. Inexact or vague preferences have appeared in the decision making literatures with a view to relaxing the burdens of preference specifications imposed to the decision-makers and thus taking into account the vagueness of human judgments. Allowing for the types of imprecise judgments in the model, however, makes more difficult a clear selection of alternative(s) that a group wants to make. So, further interactions with the decision-makers may proceed to the extent to compensate for the initial comforts of preference specifications. These interactions may not however guarantee the selection of the best alternative to implement. To circumvent this deadlock situation, we present a procedure for obtaining a satisfying solution by the use of linguistic quantifier guided aggregation which implies fuzzy majority. This is an approach to combine a prescriptive decision method via a mathematical programming and a well-established approximate solution method to aggregate multiple objects.

• Journal of the Korean Operations Research and Management Science Society
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• v.27 no.4
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• pp.111-126
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• 2002

This paper presents an interactive decision procedure to aggregate each group member's preferences when each group member articulates his or her preference information incompletely. An index, an indicative for the preference strength between alternatives, is derived to aid each decision maker to articulate preference information about alternatives. We develop a mathematical programming model that can establish dominance relations when the preference information about values of alternatives, attribute weights, and group member's importance weights are provided incompletely. Also, the preference relation between alternatives is to be considered in the model. Based on the preference strength measure and mathematical model, we develop an interactive group decision support procedure.

• 대한공업교육학회지
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• v.41 no.1
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• pp.108-127
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• 2016

We confront incessant choices in life. A person or a group stands at a crossroad continuously and make decisions under limited conditions in each time in order to achieve a goal. These series of processions are referred to as decision making and dominates our actions. Based on this view, the decision making is crucial and it secures its own position in school education as well as in real life. The purpose of this study is to develop decision making skills instructional model that can be applied to improve decision making skills in technological subjects. The components of decision making skills in technological education was problem recognition, problem identification, alternative production, alternative assessment, optimum selection, optimum evaluate. An instructional models for improvement of decision making skills in technology education and examination was designed according to the components of decision making skills in technological education. Depending on the components of decision making skills developed a teaching material to experience each step. And in the teaching material was to verify the improved decision-making skill. Accordingly, a decision making instruction model in technology is expected to contribute to enhance students' decision making skills.

• Journal of Korean Academy of Nursing Administration
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• v.7 no.2
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• pp.253-263
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• 2001

Purpose : To determine the change of effects of nursing ethics education on the nurses' ethical decision making with the time relapse of one month, three months and six months. Method : Thirteen participated in free discussion group, and fourteen participated in expert-guided discussion group for five weeks. Two weeks before the education, DIT and JAND were assessed, and JAND was assessed again on month, three months and six months after the five weeks' education program. Results : 1) Average realistic scores of JAND did not showed significant differences as times went by. However, scores were highest at three months after the education in general. 2) In both of free discussion and expert-guided discussion group, JAND score increased after the education, and highest at three months in general. 3) Low level moral development group showed highest scores at one month after the education, and declined at three month. However, in middle and high level of moral development groups, scores were higher at three months than at one month after the education. Scores were declined again at six months after the education. Conclusion : Effects of moral education program were highest at three months after the education, and were lessened as times went by. Especially for the low moral development group, effect was not continued more than one month. Therefore, more persistent, periodic education program was required until the ability of ethical decision making is settled down.