• Journal of Digital Convergence
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• v.12 no.2
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• pp.243-248
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• 2014

The demand for messenger service goes on growing rapidly with widespread use of smartphones. Generally, the smartphone messenger provides group communication functions in which users can make the group and communicate with each other. In the mobile meeting, the attendees can participate in the meeting with use of smartphone messengers wherever they are. To make the mobile meeting put to practical use, the mobility and privacy should be ensured to attendees. To satisfy the mobility requirement, the user which is not belong to the group members should not be able to participate in the meeting. To ensure the privacy requirement, the attendees should have not to repudiate the meeting results. In this study, the mobile meeting authentication scheme is proposed which provides mobility and privacy. The proposed scheme consists of meeting group creation, group key generation, group signature and verification protocols. All attendees should have to participate in the signature verification because it is based on the challenge-response type protocol. Thus, it's not possible to collude with malicious attendees to change the meeting results.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.179-190
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• 2020

As the business environment is rapidly changing with globalization and complexity of information flows, the uncertainty is also very increased for project environment. Although many studies have been conducted to find out the critical factors for project success, there still exist different views to define project success. Furthermore, implementing success formula for one project does not necessarily guarantee a success for another project since there are other elements that impede the success of project. In this regards, it is imperative to examine what are the barriers to project success. This study aims to examine the barriers that impede the success of project. Past literature was thoroughly reviewed to collect and develop a preliminary list of elements that affected project performance negatively. Experts were interviewed to refine the list and the final list of the measurement items were developed. A survey questionnaire was developed with the final list of measurement items, and a survey was conducted on the practitioners with project experience. After the survey, an exploratory factor analysis was conducted on the final list to extract the component dimensions which in turn formed the group of project barriers. The exploratory factor analysis provided ten factors, which are difficulty of process management, failure of project feasibility analysis, cost overruns and lack of cost benefits, unclarity project plan, strategic consistency error, stakeholder conflict, inaccuracy of requirement definition, disturbance of communication, technical environment change, negative attitude of top management.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.509-509
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• 2022

Rice has always been the anchor of food security in the Philippines and the government is adamant about sustaining rice production by ensuring reliable irrigation water availability. Among the numerous irrigation schemes, the importance of the Pulangui River Irrigation System (PRIS) is undeniable, as it is the largest and primary irrigation source for rice production areas which are considered the food basket in Northern Mindanao. However, the ageing irrigation structures, unlined canals, long-standing water delivery systems, and climate change are compromising the performance of PRIS; and every year, during the dry and wet season, the maximum rice irrigable area is not achieved. From the field-scale water management perspective, untimely irrigation application, an unregulated roster of turn for irrigation among farmers, and the traditional practice of flooding the rice fields are the main causes of substantial water losses in conveyance, distribution, and farm application of irrigation water. Hence, proper irrigation scheduling is crucial to cultivate the maximum irrigable area by ensuring equity among the farmers and to increase the water use efficiency and yield. In this study, the FAO single crop coefficient approach was adopted to estimate rice water requirements, which were subsequently used to suggest appropriate irrigation schedules based on the recommended field-scale rice cultivation practices. The study results would improve the irrigation system management in the study area by facilitating in regulating the canal water flows and releases according to suggested irrigation schedules that could lead to increased benefited area, yield, and water efficiency without straining the available water resources.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.2
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• pp.157-166
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• 2007

Moderns have desire likely to be further good-looking concomitant with a qulitative advancement of the life. Orthognathic surgery for the correction of dentofacial deformities is a common elective procedure. It's possible to occur many complication during the operations and especially, an excessive bleeding of those may be fatal and so a tranfusion is performing for the prevention and management of that. The most notable of these for reduction of blood loss is the utilization of induced hypotensive anesthetic technique to reduce the mean arterial pressure between 55 and 60 mmHb. Another method for dealing with blood loss following orthognathic surgery is the transfusion of blood obtained as an autologous tranfusion or from banked blood. Some of the disadvantage of banked blood are overcome with the use of predeposited autologous transfusion. But currently, surgeons try so that even autologous transfusion may not transfuse the patients. We made a comparative study of hematologic change and transfusion requirement based on a series of 200 patients who had an orthognathic surgical procedure at Chonbuk National University during the period 2001-2005. This study is to make a comparative analysis of an post-operative hematologic (Hemoglobin, Hematocrit, Red blood cell) change and duration of the procedure under induced hypotensive anesthesia in healthy orthognathic patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.382-390
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• 2018

This study developed a model to evaluate the quality management system of a medical device manufacturing company, and applied it to medical device manufacturers to understand the impact on business performance in response to international regulations and industry's change. This study prepared preliminary items, defined four (4) major factors (Plan-Do-Check-Act) that consist of the evaluation layers and items per category according to prior research review and expert interview, and calculated the weight and importance using AHP. The study results showed that responsibility & authority and quality objective in Planning Category, product-related requirement and R&D in Doing Category, Measuring and monitoring in Check Category, and review of meeting Regulatory and regulation in Action Category are relatively more important factors. The evaluation model developed based on the calculated weight and importance to business performance was applied to medical device manufacturers to investigate and analyze the implementation level of QMS and its impact on business performance according to each category. Most medical device manufacturers to be studied showed a reasonable level of QMS and effective business performance. Almost all the evaluation layers and items in the four (4) factors had a significant influence on business performance. Although the medical device quality management system is aimed mainly at license acquisition, it is important that management environment factors not related directly to licensing and authorization are important to business performance, and it is effective when these factors are integrated and operated within and outside the manufacturer.

• Korean Journal of Construction Engineering and Management
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• v.16 no.3
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• pp.101-112
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• 2015

In the 1950s, the concept of configuration management (CM) was started by the US Department of Defense (DOD). Later, it has begun to be applied in aerospace, software, engineering, construction, and nuclear power industry. However, configuration management (CM) in the Korean nuclear industry was firstly utilized in 2006 only for selected parts of facilities, while the US nuclear industry has applied CM for the facilities' entire systems since 1990s. Furthermore, configuration management (CM) is in its conceptual stage in the Korean nuclear industry because of ambiguous CM concepts, lacks of CM professional manpower, non-computerization, and inadequacy of CM procedures and processes. In order to address this issues, seven industries (including defense, aerospace, software, engineering, architecture, civil engineering, nuclear power) that utilize the concept of configuration management (CM) were compared and analyzed based on the CM purpose, technique, and life-cycle perspectives. By an extensive literature review and expert interviews, this paper developed a framework of configuration management (CM) for the nuclear industry. And also, a list of functions based on life-cycle stages and CM techniques are developed for clarifying CM framework in order to promote practical applications.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1764-1776
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• 2017

To achieve economic stability, distribution Company as an economic institution should be managed by various processes. In this way, knowledge of different processes is the first step. Furthermore, expectations, outputs, requirement data, and sub-processes should be extracted and determined. Accordingly, to assign the performance responsibility of each process, the decision-making points must be introduced and, the deviation or change in set-points should be investigated into processes. Also, the performance of processes could be monitored by introducing of the sub-indictors. In this study, a practical method is presented for monitoring of reliability and power loss indices from viewpoint components' supply chain into the distribution network. At first, the visibility model of the supply chain is illustrated by focus group and the sub-indicators are extracted for each process of this chain. Then, validation and verification of the sub-indicators are accomplished by the Delphi method and, an information dashboard is presented by confirmed the sub-indicators and statistics methods. Finally, the proposed method is investigated by real data in a typical network and the results are analyzed.

• The Journal of Sustainable Design and Educational Environment Research
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• v.10 no.2
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• pp.61-72
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• 2011

The purpose of this study is to carry out the research of the satisfaction level of consumers (students and teachers) and managerial characteristics for model classes of the subject classroom system and to draw the effective plan of the system. The conclusions are as follows First, the biggest advantage of the system is to fulfill the educational goal according to an individual level and ability of each student while the biggest disadvantage is the inconvenience of students to change their classrooms for each specific class. Second, it is necessary to rearrange the classrooms according to the applied subjects from the aspect of curriculum management since the time frame is not convenient for recess. English and mathematics are required preferentially as applied subjects, however Korean (as a national language) and science are needed to be taught with level-differentiated classes, too. The ideal size of classes is most likely 20-25 students according to the result of research. Lastly, the space of environment is another requirement to secure smooth flow of students' movements and extra space for technical devices used for information research. The above analysis indicates the necessity of supplementation in space planning for further implementation of subject classroom system in secondary school.

• Industrial Engineering and Management Systems
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• v.13 no.2
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• pp.148-153
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• 2014

Sustainable development has always been the top agenda of many governments. Especially, the concept of 'Ecological Civilisation (EC)' is gaining substantial attention from China's new leaders. However, regional government officers may manipulate or change top level policy in order to suit their own interests or if they are unable to meet the varied pressures of achieving the set measures. Thus, policy makers can unwittingly cause a negative or positive impact on the firms or regional development through the implementation of EC regulations and the requirement to measure, monitor and report performance measurement (PM) information. This can potentially have significant consequences for the firms, the industry sector, and China as a whole. The aim of this research is to explore and evaluate previous work focusing on the relationship and links between regulation and PM. This research will make a significant knowledge contribution to the emerging and yet important area in EC related research. A good understanding of the linkages between PM and EC will assist policy makers to better formulate suitable regulatory control mechanisms at the field level. Moreover, they may take the PM and EC linkages into consideration when setting policy frameworks by minimizing the negative effects and take advantages of the positive consequences.

• Nuclear Engineering and Technology
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• v.39 no.4
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• pp.257-272
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• 2007

Supercritical water-cooled reactors (SCWRs) are recognized as a Generation IV reactor concept. The Super LWR is a pressure-vessel type thermal spectrum SCWR with downward-flow water rods and is currently under study at the University of Tokyo. This paper reviews Super LWR safety. The fundamental requirement for the Super LWR, which has a once-through coolant cycle, is the core coolant flow rate rather than the coolant inventory. Key safety characteristics of the Super LWR inhere in the design features and have been identified through a series of safety analyses. Although loss-of-flow is the most important abnormality, fuel rod heat-up is mitigated by the "heat sink" and "water source" effects of the water rods. Response of the reactor power against pressurization events is mild due to a small change in the average coolant density and flow stagnation of the once-through coolant cycle. These mild responses against transients and also reactivity feedbacks provide good inherent safety against anticipated-transient-without-scram (ATWS) events without alternative actions. Initiation of an automatic depressurization system provides effective heat removal from the fuel rods. An "in-vessel accumulator" effect of the reactor vessel top dome enhances the fuel rod cooling. This effect enlarges the safety margin for large LOCA.