• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.8-13
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• 2007

During the last years, there has been an increased interest in the new energy such as photovoltaic(PV) system from the viewpoint of environmental pollution. In this regard, this paper estimates the power quality of grid-connected PV system. As the maximum power operating point(MPOP) of photovoltaic(PV) power systems alters with changing atmospheric conditions, the efficiency of maximum power point tracking(MPPT) is important in PV power systems. Moreover, grid-connected PV system occurs some problems such as voltage inequality and harmonics. Therefore, this paper presents the results of a grid-connected PV system modeling that contains incremental conductance MPPT controller by PSCAD/EMTDC simulator and investigates the influence that can occur in the grid-connected PV system from aspect of power quality, i.e. voltage drop, total harmonic distortion(TDD) and total demand distortion(TDD). For the case study, the measured data of the PV way in Cheongwadae, Seoul, Korea is used.

• The Journal of Sustainable Design and Educational Environment Research
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• v.9 no.1
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• pp.41-51
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• 2010

It is high level of management activity for the fixed property of building to operating spaces for education in university campus. Therefore, this study is focused on definition of the factors for analyzing the actual conditions of space operation and application of them to C university campus in Gyeongbuk in the aspect of infrastructure of university and efficiency of space operation. These analytical factors are the rate of lecture and experimentation room, the rate of theoretical and experimental subject in curriculum and unit area for infrastructure and the rate of use, turnover rate and occupation rate per lecture for space operation. If the analytical factors of space operation are systemized as program module for space operation, the space management system of university campus will be characterized on the foundation of university information system. And it will be able to support the decision making about space management. It needs to integrate various type of information and data of university to increase the efficiency of decision making.

• Journal of Korean Elementary Science Education
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• v.22 no.1
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• pp.121-129
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• 2003

The enhancement of inquiry skills has been emphasized as a important objective of science education for a long time. Of these, the observation is not only a simple and basic skill, but also a very important skill, in aspect of gathering informations about the nature of all things around us, through interaction between the sense organs of body and objectives. The purpose of this study is to investigate the results of observations about the grasshopper(Oxya chinesis), made by the elementary student from the 3rd to the 6th grade, and to make use of them as the basic materials for the observative teaming and the evaluation of the observation ability. Through this study, the collected items of observation are as follows For grasshopper, a total of observation items is 95, 70 using the sight sense, 13 using the tactile sense,7 using the olfactory sense. 3 using the palate sense and 2 using the auditory sense. In this study, the findings of elementary student's observation are as follows. 1. On the whole, most of students have observed mainly by the sight and the tactile sense, when observing the grasshopper. 2. It is showed a tendency that the observation ability of student is increased with the higher grade in elementary school. 3. As the grade ascends. the observations with operating are increased, also the quantitative expression and interpretation about them are increased. 4. In the case of same grade, there is no significant difference between students' gender, though girls' ability of the observation showed somewhat higher than boys' 5. Occasionally, the interpretations on the observative facts made by student, are inaccurate. Basis on the above results, we suggested some directions for the improvement of the observative learning program in science classroom of elementary school. First, the teacher have to serve as a guide and encouragement in the observative learning class, to be accomplished the various observation, which all the sensory organ can be used by student than the sight sense. Second, to get elevated the ability of observation, it is necessary that some experimental tools(magnifying lens, stereoscope, auxiliary implements etc.) are utilized. Third, the teacher have to make often endeavors showing an example of operation, to be activated the atmosphere of operative observation.

• Journal of Korea Water Resources Association
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• v.47 no.10
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• pp.891-906
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• 2014

This study suggests the hedging rule of MIP (Mixed Integer Programing) in counting the risk evaluation criteria of the objective function and constraints in order to provide the optimum operating rule in reservoir system as constraining water shortage as much as possible which may happen in the downstream control point of water supply in the aspect of water system management. The proposed model is applied to the Han-river reservoir system for two testing periods (Case I: Jan. 1993~Dec. 1997, Case II: Jan. 1999~Dec. 2003). The model based on the hedging rule with trigger volume, estimated in this study shows that in Case I, the monthly minimum discharge was $310.6{\times}10^6m^3$ in the single operation, $56.3{\times}10^6m^3$ in the joint operation, and $317.5{\times}10^6m^3$ in the hedging rule and also, in Case II, the monthly minimum discharge was found to be $204.2{\times}10^6m^3$ in the single operation, $111.2{\times}10^6m^3$ in the joint operation, and $243.7{\times}10^6m^3$ in the hedging rule. In conclusion, the hedging rule, proposed in this study can decrease vulnerability while guarantees reliability and resiliency.

• The Journal of Fisheries Business Administration
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• v.36 no.3 s.69
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• pp.1-24
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• 2005

Korean fishery wage system has been evolved with the different titles. However, Since the law of fishing crew was enacted in 1984, the fishery wage system has been established as a rate system, which is a legal term. The present rate system in practice shows various contents and modalities, depending on fisheries and regions, but the fisheries of large trawl cooperative employ a rate system of fixed plus rate wage. However, such change did not transform basically the properties of pure rate scheme. As well known, fishing vessel owners face an awful lot of difficulty in managing and controlling effectively the production process because fishing activities are carried out in the seas remote from the land. Thus, it tend to be inevitable for vessel owners to employ a rate system to induce fishermen's positive motivation for promoting productivity and saving operating costs. However, the rate system has worked out as a driving force, which induce an increase in production more strongly under the expansion of vessel numbers and power and the keener competition of fishing activities. Even though the control mechanism of fishing instruments are well established, fishermen become naturally to have an incentive to increase their fishing effort for maximizing production since they are able to raise their shares by maximizing the quantity harvested. Thus, as far as the rate system exists, fisheries administration may have much difficulty in realizing its fishery management goals only through vessel reduction and fishing gear regulations. Also, under the rate system fishery management authority may be in face of a serious dilemma between the spontaneous rate system and vessel reduction policy. If the realistic aspect of the rate system is recognized and resource restoration and profit promotion are main policy goals, it is necessary to develop effective ways to control vessel owners' and fishermen's production-maximizing motives at an appropriate level. From this point of view, it seems reasonable to introduce TAC system by species or by fisheries into the existing fishery system. The research results suggest that if the fisheries administration could understand clearly the spontaneous fisheries wage system, it would know the norm of TAC and the basic reasons for illegal fishing activities and thus it would be able to develop and implement more realistic resource management policies.

• Quality Improvement in Health Care
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• v.11 no.1
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• pp.16-30
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• 2004

Background: Although the number of cancer patients increase, the resources for cancer management are not increased. If the outpatient chemotherapy administration room is operated, the shift of patients from inpatient 10 outpatient is occurred. So the capacities for chemotherapy increased and the shifted rooms were occupied with new non-chemotherapy patients. The income of the hospital increased. The purpose of this study was to assess usefulness and cost-effectiveness of the outpatient-chemotherapy adminstration model. Method: There are six beds, two chairs and two nurses and one personnel in the outpatient chemotherapy room. The satisfaction study by patients/family and doctors and the cost analysis over 12 months, by comparing costs of chemotherapy administration at outpatient chemotherapy room with inpatient at ward and inpatient-nonchemotherapy at ward were done. Results: The 97.1 percent of patients/family and the 94.4 percent of doctor who involved chemotherapy were satisfied with outpatient chemotherapy administration. The 91.7% of doctors said there were no differences in treatment outcome between outpatient and inpatient chemotherapy administration. The average number of patients in outpatient chemotherapy room increased from 10.7 to 15.4 but in inpatient from 19.4 to 18.3. The average number of inpatient chemotherapy were not changed related to increase of the average number of outpatient chemotherapy. The profit between outpatient chemotherapy and inpatient chemotherapy administration was 45,344,710 won and the profit between outpatient chemotherapy and non chemotherapy treatment was -185,294,614 won. Conclusion: The outpatient chemotherapy administration model is good for patients/family, doctors and hospital partially. But the hypothesis described above was not correct. The process of cancer patients treatment were from diagnosis and treatment to first administration of chemotherapy. So the shift from inpatient to outpatient was not occurred. In economic aspect, the profit between outpatient chemotherapy and non chemotherapy treatment was in the red. As the level of health care fees was so low, the hospitals hesitate operating the room of outpatient chemotherapy. It is necessary to raise the level of health case fees for outpatient chemotherapy administration.

• Journal of the Korean Society of Safety
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• v.28 no.1
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• pp.117-124
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• 2013

Emergency operating procedures(EOPs) of nuclear power plants should be described considering the cognitive capability and limitation of operators and provide appropriate information in the aspect of human factors. Procedures which doesn't consider cognitive characteristics of operators can become causes of human errors. In previous researches, in order to reduce these problems related to the description of EOP, an improvement suggestion for EOP writer's guide has been proposed, which is reflected human factors aspects that should be considered when describing EOPs. The proposed items, however, have a necessity to be validated because it was listed from various documents such as standards and guidelines without any special validation process. For that reason, in this study, a validation process were performed to show that procedures, which are described in compliance with the requirement items proposed in the improved EOP writer's guide, have positive effects in the aspects of human errors and performance comparing with previous procedures. Experiments were performed to compare the performances of two tasks which are described in compliance with each writer's guide of before and after the improvement During each task was performed in experiments, changes of physiological responses such as EEG and ECG were measured to evaluate the cognitive workload and the stress of operators in each task. And also, as the performance, frequencies of errors and cognition speeds of each task were evaluated. In the results of the experiment, the portions of the ${\beta}$ wave decreased in the tasks overall after the improvement. In the case of ECG, change rates of the mean of R-R interval were decreased in the tasks after improvement. In the results of the performance, the cognition and the response time of the tasks after the improvement were predominant with statistical significancies. Error times in the tasks after improvement were decreased or same to the tasks before improvement. Conclusively, it was validated that the procedures were described in compliance with the improved EOP writer's guide had effects on the reduction of human errors and improvement of performance.

• Proceedings of the Technology Innovation Conference
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• 1998.06a
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• pp.116-127
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• 1998

The Necessity of Cyber University. Within the rapidly changing environment of global economics, the environment of higher education in the universities, also, has been, encountering various changes. Popularization on higher education related to 1lifetime education system, putting emphasis on the productivity of education services and the acquisition of competitiveness through the market of open education, the breakdown of the ivory tower and the Multiversitization of universities, importance of obtaining information in the universities, and cooperation between domestic and oversea universities, industry and educational system must be acquired. Therefore, in order to adequately cope wi th these kinds of rapid changes in the education environment, operating Cyber University by utilizing various information technologies and its fixations such as Internet, E-mail, CD-ROMs, Interact ive Video Networks (Video Conferencing, Video on Demand), TV, Cable etc., which has no time or location limitation, is needed. Using informal ion and telecommunication technologies, especially the Internet is expected to Or ing about many changes in the social, economics and educational area. Among the many changes scholars have predicted, the development and fixations of Distant Learning or Cyber University was the most dominant factor. In the case of U. S. A., Cyber University has already been established and in under operation by the Federate Governments of 13 states. Any other universities (around 500 universities has been opened until1 now), with the help of the government and private citizens have been able to partly operate the Cyber University and is planning on enlarging step-by-step in the future. It could be seen not only as U. S. A. trying to elevate its higher education through their leading information technologies, but also could be seen as their objective in putting efforts on subordinating the culture of the education worldwide. UTRA University in U. S. A., for example, is already exporting its class lectures to China, and Indonesia regions. Influenced by the Cyber University current in the U.S., the Universities in Korea is willing .to arrange various forms of Cyber Universities. In line with this, at JUNAM National University, internet based Cyber University, which has set about its work on July of 1997, is in the state of operating about 100 Cyber Universities. Also, in the case of Hanam University, the Distant Learning classes are at its final stage of being established; this is a link in the rapid speed project of setting an example by the Korean Government. In addition, the department of education has selected 5 universities, including Seoul Cyber Design University for experimentation and is in the stage of strategic operation. Over 100 universities in Korea are speeding up its preparation for operating Cyber University. This form of Distant Learning goes beyond the walls of universities and is in the trend of being diffused in business areas or in various training programs of financial organizations and more. Here, in the hope that this material would some what be of help to other Universities which are preparing for Cyber University, I would 1ike to introduce some general concepts of the components forming Cyber University and Open Education System which has been established by JUNAM University. System of Cyber University could be seen as a general solution offered by tile computer technologies for the management on the students, Lectures On Demand, real hour based and satellite classes, media product ion lab for the production of the multimedia Contents, electronic library, the Groupware enabling exchange of information between students and professors. Arranging general concepts of components in the aspect of Cyber University and Open Education, it would be expressed in the form of the establishment of Cyber University and the service of Open Education as can be seen in the diagram below.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.1
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• pp.13-20
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• 2009

Background In contrast to defects of the mandible and mouth floor region, in the defect of maxilla, the availability of firmly attached oral and nasal mucosal linings is needed. In addition to it, in consider of operation field, operating convenience, and esthetics, reconstruction using prelaminated flap is strongly recommended. Therefore we consider the prelaminated flap through the cases that is reconstructed using prelaminated forearm flap and prelaminated scapular flap. Patients and Methods From 2001 to 2008, in OMFS SNUDH, there were 6 cases that had reconstruction using prelaminated forearm free flap and other 3 cases that had reconstruction using prelaminated scapular flap of maxilla. The average age of patients that were reconstructed using prelaminated forearm free flap was 47.5 years, the average prelaminated period (after $1^{st}$ operation ${\sim}$ until $2^{nd}$ operation) was 51.8 days and the average follow-up period after $2^{nd}$ operation was 35.3 months. As well, the average age of patients that were reconstructed using prelaminated scapular free flap was 37 years, the average prelaminated period (after $1^{st}$ operation ${\sim}$ until $2^{nd}$ operation) was 57 days and the average follow-up period after $2^{nd}$ operation was 42.3 months. Results Except 1 case that were reconstructed using prelaminated scapular flap, we could get firmly attached oral and nasal stable skin(mucosal like) lining, more adequate thickness flap than any other flap and improved esthetic and functional results in the other 8 cases that were reconstructed using prelaminated flap. The complications of the prelaminated forearm flap cases were inconvenient swallowing, sputum, limitation of mouth opening and difficult mastication. It came from flap shrinkage of the flap in some aspect, as well as other combined operations such as mass resection or RND. The difficult point of the reconstruction of prelaminated scapular flap was the possibility of vascular damage at preparation of flap in $2^{nd}$ surgery. The damage could cause the failure of the prelaminated scapular flap. And the skin-lining of the prelaminated flap had limitations, so it is needed to study about the cultured oral epithelium-lining flap instead of the skin-lining flap. Conclusion We considered about advantages, complications and notable things of prelaminated flap through maxillary reconstruction cases using prelaminated forearm flap and prelaminated scapular flap so far. Furthermore, we should go on studying for functional reconstruction of prelaminated fasciomucosal flap using cultured oral epithelium.

• Journal of Korean Institute of Fire Investigation
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• v.6 no.1
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• pp.49-66
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• 2005

The purpose of this study is to present reference data to be considered in designing fur the fire safety of atrium buildings. This study deals with the characteristics of atrium buildings in the fire safety aspect, analysis of fire examples and foreign fire codes of atrium space. And con-crete factors to be consigning fur the fire facilities of atrium buildings are presented. Recently many atrium spaces have been built in Korea. They provide new experience of space with resident and pedestrians. However, because of the lack of knowledge in design principle and disaster prevention, large loss of lives is expected in an emergency situation. cion. Therefore safety ensuring from the case is urgently needed. The following is the summary on the standard of effective fire facilities for the atrium. 1. The smoke control. inside atrium must use the machine ventilation in the atrium. 2. It is desirable to divide the section between atrium and nearby living room by anti-smoke screen in order to prevent damage by smoke when fire break out. 3. It is desirable to instill an excellent fire detector like infrared light detector as a replacement of old one. 4. It is desirable to transfer from closed operating sprinkler to fire-cycle sprinkler equipment or ablative sprinkler when the height is lower than 20m.