• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.99-108
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• 2006

Since mold industries are regarded as belonging to three types of bad business, capable young people are reluctant to work in this field. The industries are hard to employ skilled workers who have much experience and knowledge On the mold manufacturing. Thus, effective CAM systems are required for unskilled workers to create process plans and NC data for the manufacturing, and process plans play important roles in the downstream manufacturing processes, such as NC machining, polishing, and final assembly. This study proposes a decision support system that facilitates unskilled workers to easily select high quality NC-data, as well as to increase productivity. The proposed system is assumed to follow a CAM operation scenario that consists of next three steps: 1) identifying several process plans and enumerating feasible unit machining operations (UMOs) from material and part surface information, 2) creating all feasible NC-data based on UMOs using a commercial CAM system, 3) selecting the best NC data among the feasible NC data using four screening criteria, such as machining accuracy, machining allowance, cutting load, and processing time. A case study on the machining of a camera core mold is provided to demonstrate the proposed system.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.70-76
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• 2007

The main purpose of this study was to realize Mountain Search and Rescue System based on Ubiquitous Sensor Network for applying search and rescue operations in the mountains. The on-site survey was conducted in order to test the possibility of data reception rate and sensor network stability, ten nodes was installed on the trail at 100m intervals Unson waterfall to Kwanumbong in Kyeryongsan national park. The results showed that the data reception rate was over 90.0% at least. To test sensor network stability, nodes were randomly turned off one by on. The result was 100% functionality.

• Journal of Distribution Science
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• v.14 no.12
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• pp.31-41
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• 2016

Purpose - This study investigates whether corporate social responsibility(hereafter CSR) management activities affect companies' performance. Depending on the CSR management activities and companies' type (national and multinational), we examined whether there is any difference in their CSR activities on Corporate Performance. Research design, data, and methodology - Data were collected from 230 surveys with a sample group consisting of employees in multinational corporations located in Seoul and Gyeonggi and 224 copies were used from 3 May 2016 to 17 May 2016. The data was analyzed by SPSS 21.0. Results - The empirical results show that CSR management activities positively influence on financial and non-financial corporate achievement and CSR may be interpreted as a strategic method to improve corporate value. But the impacts of CSR activities on performance were different between domestic and multinational corporations. The reason that the legal responsibility was overruled as a factor for financial and non-financial achievement in domestic company may be that CSR management activity is perceived as an indulgence to hide or beautify negative behavior regarding corporate illegal behavior, thus it does not deliver value. Conclusions - CSR activities can be delivered differently between domestic and multinational corporations, and further study should be done why there are differences between corporations.

• Korean Management Science Review
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• v.32 no.3
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• pp.71-89
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• 2015

This research empirically investigated the influence factors on the activation of environmental innovations (EI) in Korean manufacturing firms. In this study, external factors (compulsory demand, government regulation, normative pressure and imitative pressure) and internal factors (environmental resources, top management support, integration of environmental tasks, capabilities of environmental personnel, and environmental strategy/environmental management systems) were totally considered. The results of a multiple regression analysis showed that influence factors such as top management support, environmental resources and integration of environmental tasks have a significant and positive impact on levels of EI. However, the effects of external factors were not statistically significant. We also examined whether capabilities of environmental personnel as well as environmental resources, which are directly related with degrees of EI, have a moderating impact on relationships between other internal factors and levels of EI. With a subgroup analysis, the moderating role of abilities of environmental personnel were empirically confirmed. Through a multiple regression analysis, the direct effects of external factors on the adoption or construction of internal factors were demonstrated. The effects of government regulation, normative pressure and imitative pressure on internal factors were significant and positive. It was also found that external factors have indirect effects on EI through internal factors. Finally, the results of multiple regression analyses indicated that EI positively influences the achievement of environmental competitive benefits, and environmental competitive advantages can improve the organizational performance of a firm.

• Korean Management Science Review
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• v.32 no.3
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• pp.13-28
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• 2015

Using the most recent dataset of Korea and U.S. household finance, this study analyzed demand and adequacy of private pensions for pre-retirees. For this purpose, 2013 Korean Retirement and Income Study (KReIS) of national pension research institute in Korea and 2013 SCF (Survey of Consumer Finances) of FRB in U.S. were used. For comprehensive comparisons of the two countries, this study classified the private pension into sub-categories such as personal pension, corporate pension, and retirement benefits, and used three different criteria including ownership, accumulated present value of each pension, and income replacement ratio of each pension. After controlling for other factors, educational level of householder and household income were critical determinants of size and adequacy of private pension in both countries. Different from Korean households, householders' gender, marital status, and health status had an important effect on the private pension size and adequacy in the U.S. In addition, home ownership significantly increased only private pension adequacy in Korea, and also increased ownership rate, size, and adequacy of private pension in the U.S. Results of this study provide useful implications for future pension system and policy in Korea.

• Management Science and Financial Engineering
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• v.22 no.1
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• pp.5-12
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• 2016

We consider a time-cost tradeoff problem with multiple milestones under a chain precedence graph. In the problem, some penalty occurs unless a milestone is completed before its appointed date. This can be avoided through compressing the processing time of the jobs with additional costs. We describe the compression cost as the convex or the concave function. The objective is to minimize the sum of the total penalty cost and the total compression cost. It has been known that the problems with the concave and the convex cost functions for the compression are NP-hard and polynomially solvable, respectively. Thus, we consider the special cases such that the cost functions or maximal compression amounts of each job are identical. When the cost functions are convex, we show that the problem with the identical costs functions can be solved in strongly polynomial time. When the cost functions are concave, we show that the problem remains NP-hard even if the cost functions are identical, and develop the strongly polynomial approach for the case with the identical maximal compression amounts.

• Korean Management Science Review
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• v.34 no.2
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• pp.15-33
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• 2017

This paper considers a Bayesian Network analysis for understanding the heterogeneous cross-category effects of different promotion activities and developing an efficient overall promotion strategy for a large retail store. More specifically we differentiate price reduction promotion and floor promotion and study their heterogeneous effect on consumer purchase behavior under a market basket setting. We then utilize Bayesian networks in identifying complex association structure in market basket dataset by analyzing the effects of different promotional activities and also include the effects of time, family income and size. We find from our Bayesian network analysis that the dominant cross-category promotion effect of price promotion is the indirect effect whereas the dominant cross-category promotion effect of floor promotion is the direct effect. Also, among the demographic variables we find that family size of the household is linked with more product categories compared to income and see that there are differences in the extent of the effects by product category. Finally, we also show the existence of products acting as a network hub and how they can be utilized by retailers faced with a limited marketing budget and suggest a more efficient promotion strategy.

• Management Science and Financial Engineering
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• v.11 no.1
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• pp.1-24
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• 2005

The results of a study of the coordination effect in stocking and promotional markdown policies for a supply chain consisting of a retailer and a discount outlet (DCO) are reported here. We assume that the product is sold in two consecutive periods: the Normal Sales Period (NSP) and the subsequent Promotional Markdown Sales Period (PSP). We first study an integrated supply chain in which managers in the two periods design a common system so as to jointly decide the stocking quantities, markdown time schedule, and markdown price to maximize mutual profit. Next, we consider a decentralized supply chain. An uncoordinated contract is designed in which decisions are decentralized to optimize the individual party's objective function. Here, three sources of system inefficiencies cause the decentralized system to earn a lower expected system profit than that in the integrated supply chain. The three sources are as follows: in the decentralized system the retailer tends to (1) stock less, and (2) keep a longer sales period, and the DCO tends to (3) stock fewer leftovers inventories and charge a higher markdown price. Finally, a numerical experiment is provided to compare the coordinated model with the uncoordinated model to explore factors that make coordination an effective approach.

• Korean Management Science Review
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• v.33 no.2
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• pp.29-47
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• 2016

Trust is formed from the day-to-day and persistent interaction relationship. The trust demands more and more at the age of uncertainty. Human beings are using media interaction. The area of communication with media is extended to virtual space. The purpose of this study is to qualitatively explain trust building process in virtual team by media using. In the pursuit of this purpose, we executed in-depth interview with the person who have experience communicating by media with a man of a complete stranger. They experienced the trust building process. Interview data were analyzed by a Structured Coding Techniques. The derived seven categories were reconstructed in consideration of the cause-and-effect relationship and the flow of events. We have discovered a new trust model that was the result from communication by a media using. The model presented is very useful to Individuals who need a new trust building relationship with stranger or virtual team member.

• Korean Management Science Review
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• v.26 no.1
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• pp.37-51
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• 2009

Korean IT industry has been given much weight in national R&D management. A negative side of this fact is that Korean economy is likely to become vulnerable to a condition of the export business in certain items of IT industry which has a serious influence on the national economy. A customized investment strategy through the analysis of technology competitiveness and R&D status in each technology of IT field is required in order to rectify the structural vulnerability and pursue a continuous growth. In this research, a strategic direction to set up an efficient investment strategy is presented. In this process, it draws a portfolio analysis with two axes of technology level and technology life cycle. It also derives a priority order of the national investment considering the degree of technological impact, marketability, and adequacy of public support from AHP (Analytic Hierarchy Process) method by a survey of IT experts. A portfolio analysis in the prior stage helps the respondents in AHP become more familiar with the alternatives' characteristics so that their decision making process more corresponds with national R&D strategies.