• Journal of Korea Society of Industrial Information Systems
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• v.29 no.5
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• pp.125-137
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• 2024

This study aims to analyze the relationship between environmental management practices and environmental operational performance, and empirically verify the moderating effect of cost structure uncertainty in this relationship. To test the hypotheses proposed in this study, a moderation analysis using hierarchical regression was conducted. Results reveal an inverted U-shaped relationship between environmental practices and operational performance, moderated by cost structure uncertainty. While environmental practices initially lead to operational performance improvements, benefits diminish beyond a certain threshold. Higher cost uncertainty lowers the optimal level of environmental practices. These findings provide important implications for corporate environmental strategy formulation. Rather than indiscriminately expanding environmental practices, firms should identify optimal levels and adopt strategic approaches considering cost uncertainty.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.1-9
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• 2021

The purpose of this study is to examine the effects of economic uncertainty on MNC investment in Malaysia from 2009 to 2019 by employing an ARDL method. The results revealed that Economic Policy Uncertainty (EPU) has a positive association with the capital expenditures of Nestle, British American Tobacco, and Public Bank in the long run. In a similar period, the Gross Domestic Product (GDP) is positively significant with the capital expenditures of British America Tobacco and Heineken. However, inflation is negatively related to the capital expenditures of British America Tobacco and Heineken. Additionally, the exchange rate has a significant and negative relationship with the capital expenditures of Nestle and Petronas, while the ECT value is negative and significant in the short run, hence confirming that co-integration exists. In view of this, it is imperative that the government plays a prerogative role to support MNC operations, as MNCs foster the developing countries' economic development through facilitating full employment. This study sets to enhance the personal knowledge of those with a strong interest in the Malaysian financial market. As long as MNCs believe that the Malaysian market has the potential to grow, they will continue to invest for the benefit of the country.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.4
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• pp.91-99
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• 2009

Because of both precise measurement and efficient quality control, coordinate measuring machines(CMMs) have been widely used in the industry. The purpose of this paper is to present a method to estimate the CMM measurement uncertainty using design of experiments. A factorial design is applied to carry out the performance test proposed by ISO 10360 and to investigate CMM measurement errors associated to orientation and length of the length bar. In order to assess the measurement uncertainty for the performance test, an analysis of the uncertainty components that make up the uncertainty budget has been carried out. The procedure for evaluating the uncertainty of it follows GUM ("Guide to the expression of uncertainty in measurement"). The results show that the proposed method is suitable to investigate CMM performance and determine the contribution of machine variables to measurement uncertainty.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.149-153
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• 2011

This study was conducted to examine the uncertainty analysis of the stem density and biomass expansion factor for Pinus rigida in Korea. A total of 57 representative sample trees were harvested. The age class in Pinus rigida forests was divided into two, which were stands with less than 20 years and more than 21 years. The influence of stand ages on biomass expansion factor showed that it was statistically significant (p=0.0001), but it was not significant on stem density (p=0.8070). The results of this study based on the uncertainty evaluation method which were suggested by IPCC guide line indicated that stem density of the stand with less than 20 years were 30.92%, while were 25.12% the stands with more than 21years. The uncertainty in biomass expansion factor of less than 20 years and more than 21 years were 60.32% and 22.42%, respectively. The uncertainty of less than 20 years was higher compared to those stands with more than 21 years. In the case of old stand, it showed the lowest uncertainty results but younger stands showed the highest uncertainty results. This study could be applied to our country's emission factor by using stem density and biomass expansion factors which were less than 20 years and more than 21 years for Pinus rigida in Korea.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1158-1164
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• 2007

Recently, the demand on the practical application of life-cycle cost effectiveness for design and rehabilitation of civil infrastructure is rapidly growing unprecedentedly in civil engineering practice. Accordingly, it is expected that the life-cycle cost in the 21st century will become a new paradigm for all engineering decision problems in practice. However, in spite of impressive progress in the researches on the LCC, so far, most researches in Koreahave only focused on roadway bridges, which are not applicable to railway bridges. Thus, this paper presents the formulation models and methods for uncertainty-based LCCA for railroad bridges consideringboth objective statistical data available in the agency database of railroad bridges management and subjective data obtained form interviews with experts of the railway agency, which are used to anew uncertainty-based expected maintenance/repair costs including lifetime indirect costs. For reliable assessment of the life-cycle maintenance/repair costs, statistical analysis considering maintenance history data and survey data including the subjective judgments of railway experts on maintenance/management of railroad bridges, are performed to categorize critical maintenance items and associated expected costs and uncertainty-based deterioration models are developed. Finally, the formulation for simulation-based LCC analysis of railway bridges with uncertainty-based deterioration models are applied to the design-decision problem, which is to select an optimal bridge type having minimum Life-Cycle cost among various railway bridges types such as steel plate girder bridge, and prestressed concrete girder bridge in the basic design phase.

• Management Science and Financial Engineering
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• v.20 no.2
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• pp.27-31
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• 2014

This paper studies the assortment optimization problem in online retailing by using a multinomial logit model in order to take consumer choice behavior into account. We focus on two unique features of online purchase behavior: first, there exists increased amount of uncertainty (e.g., size and color of merchandize) in online shopping as customers cannot experience merchandize directly. This uncertainty is captured by the scale parameter of a Gumbel distribution; second, online shopping entails unique shopping-related disutility (e.g., waiting time for delivery and security concerns) compared to offline shopping. This disutility is controlled by the changes in the observed part of utility function in our model. The impact of changes in uncertainty and disutility on the expected profit does not exhibit obvious structure: the expected profit may increase or decrease depending on the assortment. However, by analyzing the structure of the optimal assortment based on convexity property of the profit function, we show that the cardinality of the optimal assortment decreases and the maximum expected profit increases as uncertainty or disutility decreases. Therefore, our study suggests that it is important for managers of online retailing to reduce uncertainty and disutility involved in online purchase process.

• The Korean Journal of Health Service Management
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• v.9 no.4
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• pp.105-117
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• 2015

Objectives : The aim of this study was to investigate the relationship among uncertainty, self-care agency and physiological index in acute myocardial infarction (AMI) patients who underwent primary percutaneous coronary intervention. Methods : A total of 196 patients who were admitted C National University Hospital from Oct 2014 to Jun 2015 participated in the study. Data were collected with a questionnaire, and the blood pressure, HgA1C, and lipid profile levels of the patients were acquired. Results : The mean age was 69.2 (${\pm}13.0$) years, and 74 % of the patients were men. The mean score for uncertainty in illness was 48.7 (${\pm}8.8$). The mean score for self-care agency was 73.3 (${\pm}13.4$). Self-care agency showed a negative correlation with uncertainty (r=-.579, p<.001), age (r=-.732, p<.001), systolic blood pressure (r=-.265, p=.001) and HgA1C (r=-.293, p<.001). Conclusions : The results of this study can be used to develop a nursing program that prevents AMI and to improve the clinical prognosis of AMI patients.

• Korean Journal of Construction Engineering and Management
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• v.8 no.5
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• pp.191-200
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• 2007

This paper introduces a tool for predicting potential cost overrun during project execution and for quantifying the uncertainty on the expected project cost, which is occasionally changed by the unknown effects resulted from project's complications and unforeseen environments. The model proposed in this stuff is useful in diagnosing cost performance as a project progresses and in monitoring the changes of the uncertainty as indicators for a warning signal. This model is intended for the use by project managers who forecast the change of the uncertainty and its magnitude. The paper presents a mathematical approach for modifying the costs of incomplete work packages and project cost, and quantifying reduced uncertainties at a consistent confidence level as actual cost information of an ongoing project is obtained. Furthermore, this approach addresses the effects of actual informed data of completed work packages on the re-estimates of incomplete work packages and describes the impacts on the variation of the uncertainty for the expected project cost incorporating Multivariate Probabilistic Analysis (MPA) and Bayes' Theorem. For the illustration purpose, the Introduced model has employed an example construction project. The results are analyzed to demonstrate the use of the model and illustrate its capabilities.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.929-933
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• 2010

According to the IPCC guideline (2006), uncertainty assessment is very important in terms of the greenhouse gas inventory. Therefore, the purpose of this study is to estimate the basic wood density (BWD) and its uncertainty for Pinus densiflora in Korea. In this study, Pinus densiflora forests were divided into two ecotypes which were Gangwon and Jungbu regions. A total of 33 representative sampling plots was selected to collect sample trees after considering the tree ages and DBH distributions. The BWD showed statistically no difference between age classes based on IPCC's classification. While, it showed statistically difference(pvalue=0.0017) between eco-types. The BWD and uncertainty was 0.396(g/$cm^3$) and 12.9(%) for Pinus densiflora in Gangwon, while it was 0.470(g/$cm^3$) and 3.8(%) for Pinus densiflora in Jungbu. The values of the BWD uncertainty for Pinus densiflora were more precised than the values given by the IPCC guideline.

• The Journal of Information Systems
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• v.15 no.1
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• pp.191-213
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• 2006

The purpose of this research is to identify the structure among determining factors focusing on knowledge transfer and analyze and prove the causal relation on knowledge transfer in Korean companies and public corporations. The results from the analysis of data collected in this study are as follows. First, forum among organization related factors has the positive relation with uncertainty in a significant level. Second, the higher the knowledge presentation and the ease of use are among information systems related factors, the lower the ambiguity and uncertainty are. Third, among process related factors, unification has the negative relation with ambiguity and uncertainty in a significant level. Fourth, a better manpower employment contributes to a worse ambiguity and uncertainty. Fifth, ambiguity has a negative relation with knowledge transfer. In conclusion, the factors that lower the ambiguity and facilitate knowledge transfer include information systems, unification, and manpower employment. These factors, however, influence on uncertainty, which turns out to be nothing to do with knowledge transfer.