• The Transactions of The Korean Institute of Electrical Engineers
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• 제57권4호
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• pp.560-566
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• 2008

Today, as the power trades between generation companies and power customer are liberalized, the uncertainty level of operated power system is rapidly increased. Therefore, transmission operators as decision makers for transmission expansion are required to establish a deliberate investment plan for effective operations of transmission facilities considering forecasted conditions of power system. This paper proposes the methodology for the optimal solution of transmission expansion in deregulated power system. The paper obtains the expected value of transmission congestion cost for various scenarios by using occurrence probability. In addition, the paper assumes that increasing rates of loads are the probability distribution and indicates the location of expanded transmission line, the time for transmission expansion with the minimum cost for the future by performing the Montecarlo simulation. To minimize the investment risk as the variance of the congestion cost, Mean-Variance Markowitz portfolio theory is applied to the optimization model by the penalty factor of the variance. By the case study, the optimal solution for transmission expansion plan considering the feature of market participants is obtained.

• Proceedings of the KSRS Conference
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• 대한원격탐사학회 2000년도 춘계 학술대회 논문집 통권 3호 Proceedings of the 2000 KSRS Spring Meeting
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• pp.9-9
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• 2000

For the planning of future land use for economic activities, an essential component is the identification of the vulnerable areas for natural hazard and environmental impacts from the activities. Also, exploration for mineral and energy resources is carried out by a step by step approach. At each step, a selection of the target area for the next exploration strategy is made based on all the data harnessed from the previous steps. The uncertainty of the selected target area containing undiscovered resources is a critical factor for estimating the exploration risk. We have developed not only spatial prediction models based on adapted artificial intelligence techniques to predict target and vulnerable areas but also validation techniques to estimate the uncertainties associated with the predictions. The prediction models will assist the scientists and decision-makers to make two critical decisions: (i) of the selections of the target or vulnerable areas, and (ii) of estimating the risks associated with the selections.

• Educational Technology International
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• 제21권1호
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• pp.69-95
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• 2020

The purpose of this research is to analyze the predictive powers of the five technostress creators - techno-overload, techno-invasion, techno-complexity, techno-insecurity, and techno-uncertainty - in job satisfaction and teacher efficacy of primary school teachers in Korea when they incorporated mobile technology into teaching. A questionnaire was designed to measure the level of teacher's stress from technology, job satisfaction and teacher efficacy. Data were collected from 164 teachers. Multiple regression analysis was conducted to explain which area of technostress led to varying degrees of job satisfaction and teacher efficacy. The results showed that techno-complexity alone predicted both job satisfaction and teacher efficacy. The reason why techno-complexity was the only predictor is that teachers would have first needed to understand how to incorporate mobile technology into teaching, before feeling overloaded, invaded, insecure, or uncertain about it, meaning techno-complexity precedes other constructs. Therefore, the only stress factor that affected them was how to understand the complexity of mobile technology. This calls for adequate training and support from schools and governments in order for the teachers to fully incorporate technology into teaching.

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3260-3271
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• 2022

Experience shows that the solution to waste management in any national programme is lengthy and burdened with uncertainties. There are several uncertainties that contribute to the costs associated with spent fuel management. In this work, we have analysed the impact of the current nuclear data on the isotopic composition of the spent fuel and consequently their influence on the main spent fuel observables such as decay heat, activity, neutron multiplication factor, and neutron and photon source terms. Nuclear libraries based on the most general nuclear data ENDF/B-VII.0, ENDF/B-VII.1, ENDF/B-VIII.0 and JEFF-3.3 are considered. A typical NPP Krško fuel assembly is analysed using the Monte Carlo code Serpent 2. The analysis considers burnup of up to 60 GWd/tU and cooling times of up to 100 years. The comparison of results showed significant differences, which should be taken into account when selecting the library and evaluating the uncertainty in determining the characteristics of the spent fuel.

• International conference on construction engineering and project management
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1176-1182
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• 2009

Due to recession in real estate market, interest of risk analysis is increasing. Feasibility study in the first stage takes a great role in a project. There are not objectified tools which are able to cope with uncertainty of project, and feasibility study based on selected method of determinism does not include liquidity of weight risk. Also, shortage of consideration for subjective and atypical external factors causes inappropriate results. Therefore, this study proposes feasibility study model focused on risk factor influences in construction cost and sales cost. Considering effective level of cost based on objective risk factors and probable weight of risk by this model, real workers are able to bring correct and scientific decisions better than former method based on selective analysis of real estate development.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.77-78
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• 2002

A regression formula including the inlet film thickness as the parameter for the starvation factor in EHL condition is obtained by numerical analysis with Elord‘s cavitation algorithm. In addition, an apparatus for starved film thickness measurement by use of the white light interferometry is developed in order to verify the proposed regression formula. From observation results by this apparatus, the proposed regression formula can predict the reduction of central film thickness caused by starvation in a ball-plate contact with an uncertainty up to 10%

• International conference on construction engineering and project management
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.183-187
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• 2015

The Risk Management (RM) is applied for managing uncertainty of project. In this circumstance, the competences of RM have a direct effect on the performance of its application. Especially, as the RM, one of the project management areas, is a peopleoriented management field, the individual behavioral competences are significant for a risk manager. Therefore, this paper describes the development of individual behavioral competences for construction project risk manager. For this, the research classifies the individual behavioral competences of RM. And, the Exploratory Factor Analysis (EFA) are applied to verify a validity of the competences. Likewise, a reliability analysis using Cronbach's alpha values is performed to test internal consistency. Based on the results, the authors carry out the Focus Group Interview (FGI) on expert panels of construction RM to confirm the hierarchical model of the individual behavioral competences. It is concluded that the proposed hierarchical model of individual behavioral competences helps construction companies to diagnose the competences of their project risk manager for progressing.

• International Journal of Computer Science & Network Security
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• 제24권6호
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• pp.17-22
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• 2024

Software cost and schedule estimation is usually based on the estimated size of the software. Advanced estimation techniques also make use of the diverse factors viz, nature of the project, staff skills available, time constraints, performance constraints, technology required and so on. Usually, estimation is based on an estimation model prepared with the help of experienced project managers. Estimation of software cost is predominantly a crucial activity as it incurs huge economic and strategic investment. However accurate estimation still remains a challenge as the algorithmic models used for Software Project planning and Estimation doesn't address the true dynamic nature of Software Development. This paper presents an efficient approach using the contemporary Constructive Cost Model (COCOMO) augmented with the desirable feature of fuzzy logic to address the uncertainty and flexibility associated with the cost drivers (Effort Multiplier Factor). The approach has been validated and interpreted by project experts and shows convincing results as compared to simple algorithmic models.

• Journal of Korean Society for Atmospheric Environment
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• 제26권3호
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• pp.276-285
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• 2010

Recently the Korean government has tried to cut down the $PM_{10}$ concentration by the Special Law for Air Quality Improvement. But the concentrations of $PM_{10}$ have exceeded the air quality standard at most monitoring stations. Primary $PM_{10}$ emitted from various sources and emission data have large uncertainty. The biomass burning is one of the major sources of $PM_{10}$ emission. The biomass burning is composed of wood stove usage, meat cooking and agricultural combustion etc.. Activity data and emission factors for the biomass burning are limited, and it is hard to calculate the air pollution emissions from these sources. In this study, we tried to estimate the air pollution emission from residential wood stove usage. The number of total wood stoves is estimated by the survey of wood stove manufacturer. And air pollution emission factors for the wood stove are investigated using the flue gas measurement by U.S. EPA particulate test method (Method 5G). As the results, the $PM_{10}$ and CO emission factors of wood stove are estimated as 7.7 g/kg-wood and 78.8 g/kg-wood respectively. The annual $PM_{10}$ and CO emissions from wood stove are calculated as 1,200~3,600 ton/year and 12,600~36,400 ton/year in Korea. It is confirmed that wood stove is the one of major sources of biomass burning, and the survey for activity data and the measurement for emission factors are needed for reducing the uncertainty of these emission data.

• Journal of Korean Biological Nursing Science
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• 제13권1호
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• pp.16-22
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• 2011

Purpose: Hand washing has received renewed emphasis in recent years as Swine flu epidemic threaten health of public. This study aimed to describe measures used to prevent new types of influenza (NTI); describe hand washing frequency; and analyze the relationship of hand washing to locus of control, uncertainty, and state anxiety. Methods: One hundred thirty three adults participate in the questionnaire survey in which participants indicated measures they used to prevent NTI, frequency of handwashing for the prevention of NTI. They also responded to questions related to locus of control, uncertainty and state anxiety. Data were analyzed using descriptive statistics, Pearson correlation and multiple regression. Results: A majority (66.9%) of the participants indicated that handwashing was an important measure to prevent NTI. Importance of hand-washing was related the highest among the measures they used and it was significantly related to participants who had high score in internal locus of control. Other significant factor to the hand-washing behavior was state anxiety, which explained 6.9% of the frequency. Conclusion: According to the results of this study, majority of participants indicated that handwashing was one of the most important measures to prevent NTI. Nurses need to continue educating public the importance of handwashing and pay attention to personal characteristics such as internal locus of control and anxiety to promote hand-washing.