• Journal of Environmental Science International
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• v.11 no.7
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• pp.679-686
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• 2002

Turbulence greatly influence on atmospheric flow field. In the atmosphere, turbulence is represented as turbulent diffusion coefficients. To estimate turbulent diffusion coefficients in previous studies, it has been used constants or 2-level method which divides surface layer and Ekman layer. In this study, it was introduced Smagorinsky method which estimates turbulent diffusion coefficient not to divide the layer but to continue in vertical direction. We simulated 3-D flow model and TKE equation applied turbulent diffusion coefficients using two methods, respectively. Then we showed the values of TKE and the condition of each term to TKE. The results of Smagorinsky method were reasonable. But the results of 2-level method were not reasonable. Therefor, it had better use Smagorinsky method to estimate turbulent diffusion coefficients. We are expected that if it is developed better TKE equation and model with study of computational method in several turbulent diffusion coefficients for reasonably turbulent diffusion, we will able to predict precise wind field and movements of air pollutants.

• IE interfaces
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• v.14 no.2
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• pp.182-189
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• 2001

Recently the number of wireless internet service user is increasing rapidly but there are some areas in which service level has not reached the expected level yet. In this paper, we apply ACSI model to measure the current level of customer satisfaction. As a result of ML estimation, we observe that satisfaction increases as the level of perceived quality increases. However, this model does not provide flexibility of adjusting data characteristics that wireless internet service has, and it is not easy to find direct controllable feedback for better service. We propose a structural equation model that can overcome these problems and obtain that information transmission quality and proper fare policy can significantly improve the satisfaction level of wireless Internet users.

• Journal of Korean Institute of Industrial Engineers
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• v.11 no.1
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• pp.41-49
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• 1985

This paper studies the two supplier inventory system in which order-level inventory policy with constant leadtimes is adopted. An optimal ordering policy to achieve the expected minimum total inventory cost is found by utilizing the concepts of the equivalence relation. Sensitivity analysis of the system parameters, the replenishment cost and the unit price, is done through a numerical example.

• Journal of Applied Reliability
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• v.1 no.1
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• pp.65-78
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• 2001

Recently, Six Sigma to increase market share , decrease costs, and grow profit margin has been adopted by some leading companies in the world. Six Sigma is expected as the optimal movement to raise the quality level remarkably and to make enterprise culture and organization based on customer and market orientation. In this paper, we study on the idea of Six Sigma, the Internal and external success case, the reliability tools using in the Six Sigma, and the difference between the existing quality movement and Six Sigma. Also, we discuss the role of reliability In Six Sigma..

• Journal of the military operations research society of Korea
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• v.7 no.2
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• pp.100-113
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• 1981

A replacement policy for a finite time span is proposed for the cumulative process where an item can fail only when the total amount of deterioration exceeds a prespecified failure level. The optimal deterioration limit level is determined to minimize the total cost expected per unit for a given time span. An illustrative example in case of periodically inspected reformer tubes in ammonia plant is also presented.

• The Journal of Society for e-Business Studies
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• v.25 no.3
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• pp.109-130
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• 2020

Recently, the importance of research and development for technological innovation is increasing. The rapid development of research and development has a number of positive effects, but at the same time there are also negative effects that accelerate crimes of information and technology leakage. In this study, a research security level measurement model was developed that can safely protect the R&D environment conducted at the organizational level in order to prepare for the increasingly serious R&D result leakage accident. First, by analyzing and synthesizing security policies related to domestic and overseas R&D, 10 research security level evaluation items (Research Security Promotion System, Research Facility and Equipment Security, Electronic Information Security, Major Research Information Security Management, Research Note Security Management, Patent/Intellectual Property Security Management, Technology Commercialization Security Management, Internal Researcher Security Management, Authorized Third Party Researcher Security Management, External Researcher Security Management) were derived through expert interviews. Next, the research security level evaluation model was designed so that the derived research security level evaluation items can be applied to the organization's research and development environment from a multidimensional perspective. Finally, the validity of the model was verified, and the level of research security was evaluated by applying a pilot target to the organizations that actually conduct R&D. The research security level evaluation model developed in this study is expected to be useful for appropriately measuring the security level of organizations and projects that are actually conducting R&D. It is believed that it will be helpful in establishing a research security system and preparing security management measures. In addition, it is expected that stable and effective results of R&D investments can be achieved by safely carrying out R&D at the project level as well as improving the security of the organization performing R&D.

• Knowledge Management Research
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• v.13 no.5
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• pp.91-111
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• 2012

The purpose of this study is to investigate the effect of person-organization fit(PO fit) and person-job fit(PJ fit) on positive psychological capital at both team-level and individual-level. Present study intends to confirm the effectiveness through theoretical considerations and empirical analysis of positive organizational behaviors. This is expected to strengthen the basis of positive organizational behavior studies and provide the foundation to integrate positive organizational behavior to the actual organization. In order to test the hypotheses, the data were collected from multiple domestic organizations and composed 47 team-level and 244 individual-level data. For the analysis, hierarchical linear modelling(HLM) were conducted. The results of this study are as follows. PO fit and PJ fit had significant relationships with positive psychological capital at both team-level and individual-level. Also, in the relationship between the attitudes and behaviors of the members and positive psychological capital, the positive psychological capital was found to have significant effect on affective commitment and organizational citizen behaviors. The implications of this study according to the results as follows. Positive relationships of psychological capital with the antecedents and consequences variables, it is necessary for the management to magnify the strength of members in the actual operation at the organization level. Such the management of positive psychological capital can be suggested as a new approach method for achievement of the organization's goals and visions.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.169-178
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• 2020

This paper presents a study investigating the relationship between stress level and reworks for construction professionals. As employees' work-life balance (WLB) becomes more important nowadays, controlling the level of stress in the workplace becomes more important as occupational stress has negative impacts on WLB. Reworks can be one severe occupational stressor as people suffer from stress when they need to redo their works. This study hypothesizes that there is a positive correlation between reworks and level of stress, meaning that people tend to show high level of stress when they need to redo their works. The hypothesis will be tested by checking the stress level when engineers redo their works because of changes or errors. An electroencephalography (EEG) sensor will be used to measure the stress level of engineers when they redo their works. For more accurate measure of stress, the stress level will also be measured by the galvanic skin response (GSR). This experiment is expected to prove that rework process is a severe stressor for construction professionals, which will contribute to lower productivity and poorer WLB. The finding will emphasize the importance of managing reworks in the construction industry, which will eventually help construction managers to control the level of employees' stress successfully.

• Environmental and Resource Economics Review
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• v.23 no.1
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• pp.21-42
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• 2014

In this study, we are estimating the economic effects of the rising sea level due to the climate change in the Korean Eastern and Southern coastal areas. Using disaggregated regional data, we also estimate the optimal rate of coastal protection. We use FUND (The Climate Framework for Uncertainty, Negotiation and Distribution) in order to obtain estimates of the expected inundation ratios by geographical district. Our estimates suggest that in Busan the ratio of inundated land to total territory will likely constitute 3.19% by 2100, while the number in Gangwon-do province is estimated to be lower at only 0.1%. We estimate the associated economic damage to differ by geographical district with the economically active regions such as e.g. Busan and Ulsan cities, or the Gyeongsang-nam-do province, likely to sustain relatively more damage. In Busan and Ulsan where the coastal line is relatively short and the size of expected economic damage is rather high, we estimate the optimal rate of coastal protection to be at the level of 98% and 92%, respectively. In the Kyeongsang-nam-do area that is also likely to suffer a substantial economic damage due to the inundation, we suggest the optimal ratio of coastal protection to be set at the level of 78%~79%. In contrast, in the Kangwon-do province where the expected economic damage is estimated to be low, the optimal rate of coastal protection is estimated to be around 43%, depending on the scenario.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.194-195
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• 1982

Recommendaton: These are the highlights of the findings of the Timber Consumption Survey carried out by the Project in 1966, and covering consumption for the period from 1961 to 1965. The survey was oriented towards consumption for structural, commercial and industrial purposes and existing estimates for local (village-level) consumption as fuel and the like were adopted. A full report on the survey was submitted to the Bureau of Forestry in 1966. Long-term Trends: After allowance for anticipated population increase, this ten year's increase in industrial wood consumption represents a gain of about 30% in per capita consumption (from 0.0913 cu.m. per capita to 0.118 cu.m. per capita). This is only about half the expected general economic growth of about 75% (7% per annum). It is therefore likely (a) that the 1975 estimate is conservative, (b) that the consumption demand beyond 1975 may be expected to build up at a greatly increased rate. Estimated income elasticity coefficients are high, and with expected ir,creases in prosperity and population, the consumption is expected to rise to 10 million cu. meters by the year 2,000. Consumption Pattern: The breakdown of industrial consumption (1965) is given in Table 4-2, showing sawnwood consumption as the most important in 1965. The upward trend in all sectors over the 1961-65 period is expected to continue. The general consumption pattern is expected to change through 1975 with a sharp increase in the relative importance of pulp products (to 30% of total consumption) offset by declining relative importance of sawlogs. The following recommendations follow from the study: (i) Industrial forests. - A programme of establishment of consolidated industrial forests should be initiated as a matter of urgency. (ii) Fuelwood forests - Properly sited, protected and managed fuelwood forest, worked on a 20-year rotation, should be established as a nation wide basis. (iii) Hardwood utilization - Detailed investigations are required into the use of indigenous hardwoods for the pulp, particle board and hardboard industries. (iv) Mining timber - Preservation treatment of all mining timber should be enforced by law. (v) Sawmills - Licencing restrictions should be enforced to reduce the number of small, inefficient sawmills. b. Extension work should be undertaken bv government to improve sawmilling practices.