• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.1
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• pp.1-18
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• 2012

The present study provides some extensions over a recent work in Won (2011) which investigates properties of the static newsvendor problem under a schedule involving progressive multiple discounts under the assumption that demand is given exogenously. Khouja (1995, 1996) formulated the extended versions over the classical newsvendor model with various discount policies including all-units discount and/or multiple discounts and found that the extended newsvendor models with discount schedules yield higher optimal expected profits than the classical newsvendor model with no-discounts. In this study, we establish a robust conjecture as a stronger statement than Khouja's findings with regard to the general relationship among the expected profits of newsvendor models in the sense that the conjecture holds for every order quantity as well as the optimal order quantity. The conjecture encourages the newsvendor facing quantity discounts to safely implement her own discounts policy to customer or accept quantity discounts offered by the supplier even if the optimal order quantity cannot be ordered due to additional restrictions such as budget or warehouse capacity constraints because the newsvendor models with quantity discounts always yield higher expected profit than the classic newsvendor model without quantity discounts regardless of the order quantity. Results from wide experiments with various probability distributions of demand strongly support our conjecture.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.4
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• pp.403-411
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• 2010

Recently, emission tests for heavy-duty vehicles have been conducted by heavy-duty engine dynamometer. But, it contains weaknesses that present inconveniences to install and uninstall engines and limitations to reflect on practical characteristics for vehicle driving. On the other hand, chassis dynamometer test is able to differentiate characteristics of real driving patterns due to the reason that vehicles can be examined by utilizing chassis dynamometer. This study aimed at comparing the characteristic of emitting regulatory substances of urban buses on Heavy-duty chassis dynamometer. The characteristic was analyzed based on vehicle speed by using both domestic and overseas developed heavy-duty vehicle test modes. As a result, this work attempted to investigate possibilities to take advantage of Heavy-duty vehicle test modes as a method to manage emissions from heavy-duty vehicles.

• Journal of Korean Society for Quality Management
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• v.41 no.2
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• pp.221-232
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• 2013

Purpose: This paper examines risk factors which affect project success, and proposes a method utilizing the average potential satisfaction index(API) to evaluate how much the satisfaction level of the personnel involved in the project can change by reducing the risk. Methods: The current study derives 11 risk factors affecting project success from literature review and conducts survey of 253 subjects who have project work experience. A modified Kano's questionnaire using 5-point Likert-scale is applied to investigate the amount of satisfaction or dissatisfaction when the risk factors are reducted or not, respectively. Results: The respondents consider that the risk factors which include the three elements of project management(schedule, quality, cost) is more important than other risk factors related to the project environment, and technology and profitability. Conclusion: The average potential satisfaction index proposed in this study can measure the perception on the risk factors of the personnel involved in the project, since it has a strong correlation with the perceived importance by the respondents in this study.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4311-4330
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• 2015

Cloud computing has become a new paradigm by enabling on-demand provisioning of applications, platforms or computing resources for clients. Workflow scheduling has always been treated as one of the most challenging problems in clouds. Commercial clouds have been widely used in scientific research, such as biology, astronomy and weather forecasting. Certainly, it is very important for a cloud service provider to pursue the profits for the commercial essence of clouds. This is also significantly important for the case of providing services to workflow tasks. In this paper, we address the issues of workflow scheduling in commercial clouds. This work takes the communication into account, which has always been ignored. And then, a topology-based workflow-scheduling algorithm named Resource Auction Algorithm (REAL) is proposed in the objective of getting more profits. The algorithm gives a good performance on searching for the optimum schedule for a sample workflow. Also, we find that there exists a certain resource amount, which gets the most profits to help us get more enthusiasm for further developing the research. Experimental results demonstrate that the analysis of the strategies for most profits is reasonable, and REAL gives a good performance on efficiently getting an optimized scheme with low computing complexity.

• Journal of Internet Computing and Services
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• v.7 no.6
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• pp.21-40
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• 2006

As the knowledge-based society hot been constructed, the size of work process that has to be done grows big and the amount of the information that has to be analyzed increases. In the paper business process can be accurately executed by the rule agent to manage precise rules and definitions to be needed by execution of process for management of business process. And individuals con accurately measure and manage personal schedules to execute process through supporting the agent of schedule management. The model is designed and implemented for organization to improve process of control, flexibleness, agility, reliability, and reuse through business process automation and removing process overlapping and for personal to improve measuring personal process capacity and distinguishing process weak points.

• KIEAE Journal
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• v.8 no.1
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• pp.87-92
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• 2008

Sheathing work used for excavation in a crowded downtown is generally a temporary strut method using H-piles and sheathing wall includes lagging, CIP, SCW or slurry wall. A temporary strut serving the support for sheathing wall acts to resist the earth pressure, but it shall be removed when installing the underground structure members. A traditional temporary strut might cause the stress imbalance of the sheathing wall when it is demolished, resulting in time extension and the risk of collapse. A traditional temporary strut method thus needs to be improved for schedule and cost reduction, risk mitigation and for preparation for potential civic complaint. A permanent strut method doesn't require installing and demolishing the temporary structure that will lead to reducing the time and cost and the structural risk during the demolition process. And given the girder, the part of the underground structure, serves the role of strut, it can secure the wider interval compared to the traditional method, which enables to secure the wider space for the convenience of excavation as well as enhance the constructability and efficient site management. The thesis was intended to study the composite girder designed to use the strut as permanent structure so as to reduce the excavation and floor height.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.826-839
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• 2014

Fire is a continuous threat to FPSO topside modules as large amounts of oil and gas are passing through the modules. As a conventional measure to mitigate structural failure under fire, passive fire protection (PFP) coatings are widely used on main structural members. However, an excessive use of PFP coatings can cause considerable cost for material purchase, installation, inspection and maintenance. Long installation time can be a risk since the work should be done nearly at the last fabrication stage. Thus, the minimal use of PFP can be beneficial to the reduction of construction cost and the avoidance of schedule delay. This paper presents a few case studies on how different applications of PFP have influence on collapse time of a FPSO module structure. A series of heat analysis and thermal elasto-plastic FE analysis are performed for different PFP coatings and the resultant collapse time and the amount of PFP coatings are compared with each other.

• International Journal of Human Ecology
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• v.17 no.1
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• pp.39-51
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• 2016

This pilot study examined programs for early childhood education and care in three Chinese cities. The samples for this study were one university-based kindergarten, one private kindergarten (rural area), and one public kindergarten (urban area). Six types of instruments were used to assess early childhood education and care services regarding quality matters. Most questions asked were open-ended; consequently, the interview answers by kindergarten directors or teachers (as well as observations made by the researcher) formed the basis for collecting the data. Quality components for each program were determined by a comparison method. The comparison allowed the researcher to understand the range of quality education and care available as well as the variability of existing kindergarten programs in China. The findings of the investigation revealed important information on; (a) demographic information (fees, class hours, total weeks of class, vacation, number of children and staff, class size, and teacher-child ratio) (b) teacher characteristics, (c) health practices, (d) safety practices, (e) work environment, (f) physical settings, (g) play materials, (h) parent involvement, (i) nutrition, (j) daily schedule. Implications within the Chinese context for quality practices and issues to further develop and strengthen early childhood education and care systems are discussed.

• Journal of Korean Academy of Nursing Administration
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• v.15 no.1
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• pp.16-25
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• 2009

Purpose: This study was to identify the factors influencing turnover intention of nurses in small and medium-sized hospitals. Method: The participants in this descriptive survey on causal relations were 192 nurses who were working at small and medium-sized hospitals in Daegu city. The data were collected by self-reporting questionnaires and analysed by the SPSS Win 14.0 program using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients and stepwise multiple regression. Result: The mean for job characteristics scores were 2.90, the job satisfaction scores were 3.00, the organizational commitment scores were 3.00, job stress scores were 2.42, the turnover intentions scores were 3.08. Turnover intention according to general features were shown as following; age, marital status, clinical career, work schedule type, frequency of night duty. The relationship between turnover intention and job stress had positive correlation. But the relationship between turnover and other factors that job satisfaction, organizational commitment had negative correlation. The causal factors of turnover intention were organizational commitment, job satisfaction, job stress, and job characteristics, frequency of night duty. $R^=.39$. The organizational commitment were the highest significant predictors of turnover intention. Conclusions: The findings of study suggest that broad intention program should be provided to prevent problems of turnover.

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.66-72
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• 1961

A small size Fischer-Tropsch Catalyst testing apparatus, designed for an operating pressure of 150 psig, was test fabricated from ordinary schedule 40 iron pipes. The operability of the apparatus was tested by charging the reactor tube with the Lurgi Fischer-Tropsch iron Catalyst and passing through it the water gas obtained by gasifying the Korean anthracite using steam and oxygen. With the kind of catalyst charged, the apparatus was proven to daily produce about 50c.c. of synthetic greasy product, water and water soluble compounds, by running at a temperature of $250^{\circ}C$ and at a space velocity of 180 volume of gas per volume of catalyst/hr. About 20 consecutive days of operation is claimed to be sufficient for gathering an enough amount of synthetic products for such ordinary tests as distillation analysis, density measurement, iodine value determination etc. This trial fabrication of apparatus may be the first case of its kind in Korea in that the work has been conducted out in much a pilot plant scheme rather than a routine laboratory way which depends on small glass ware apparatus.