• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.12
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• pp.1777-1783
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• 2021

The use of drones is gradually increasing for the efficient maintenance of large-scale renewable energy power generation complexes. For a long time, photovoltaic panels have been photographed with drones to manage panel loss and contamination. Various approaches using artificial intelligence are being tried for efficient maintenance of large-scale photovoltaic complexes. Recently, semantic segmentation-based application techniques have been developed to solve the image classification problem. In this paper, we propose a classification model using semantic segmentation to determine the presence or absence of failures such as arcs, disconnections, and cracks in solar panel images obtained using a drone equipped with a thermal imaging camera. In addition, an efficient classification model was implemented by tuning several factors such as data size and type and loss function customization in U-Net, which shows robust classification performance even with a small dataset.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.1
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• pp.91-103
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• 2006

Given a bill of materials (BOM) tree T labeled by the breadth first search (BFS) order from node 0 to node n and a general network ${\Im}=(V,A)$, where V={1,2,...,m} is the set of production facilities and A is the set of arcs representing transportation links between any of two facilities, we assume that each node of T stands for not only a component. but also a production stage which is a possible stocking point and operates under a periodic review base-stock policy, We also assume that the random demand which can be achieved by a suitable service level only occurs at the root node 0 of T and has a normal distribution $N({\mu},{\sigma}^2)$. Then our integrated model of facility location problems and safety stock optimization problem (FLP&SSOP) is to identify both the facility locations at which partitioned subtrees of T are produced and the optimal assignment of safety stocks so that the sum of production cost, inventory holding cost, and transportation cost is minimized while meeting the pre-specified service level for the final product. In this paper, we first formulate (FLP&SSOP) as a nonlinear integer programming model and show that it can be reformulated as a 0-1 linear integer programming model with an exponential number of decision variables. We then show that the linear programming relaxation of the reformulated model has an integrality property which guarantees that it can be optimally solved by a column generation method.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.4
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• pp.405-419
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• 2007

A series of tracer experiments for the evaluation of atmospheric dispersion was performed over the urban area of Seoul using two inert, non-deposition perfluorocarbon (PMCH and m-PDCH) gases during three years campaign on 2002, 2003 and 2005. 30 sampling sites for collecting these tracers were located along two arcs of 2.5 and 5 kilometers downwind from the release point. About ten measurements which each lasted for 2 hours or 4 hours were made over the two consecutive days during each campaign. CALPUFF and MM5 meteorological model were applied to evaluate the urban dispersion in detail. Size of Modeling domain was $27\;km{\times}23\;km$ and the fine nest in the modeling domain had a grid size of 0.5 km. The results showed that CALPUFF dispersion model had a tendency to estimate tracer concentrations about $2{\sim}5$ times less than those of ambient samples under many conditions. These consistent inaccuracy in urban dispersion was attributed to inherent inaccuracy and lack of details in terrain data at urban area.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.117-125
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• 2012

Although many studies have been conducted to extract buildings from airborne lidar data, most of them assume that all the boundaries of a building are straight line segments. This makes it difficult to model building boundaries containing curved segments correctly. This paper aims to model buildings containing curved segments as combination of straight lines and arcs. First, two sets of boundary points are extracted by adaptive convex hull algorithm and local convex hull algorithm with a larger radius. Then, arc segments are determined by average spacing of boundary points and intersection ratio of perpendicular lines. Finally, building boundary is modeled through regularization of least squares line or circle fitting. The experimental results showed that the proposed method can model the curved building boundaries as arc segments correctly by completeness of 69% and correctness of 100%. The approach will be utilized effectively to create automatically digital map that meets the conditions of the Korean digital mapping.

• The Journal of Korean Academic Society of Nursing Education
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• v.21 no.2
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• pp.266-275
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• 2015

Purpose: The aim of this study was to evaluate the effect of student question-centered lessons for bi-directional faculty-student communication. Methods: This study performed one-group pretest-posttest design; participants were university students majoring in health science (nursing 58, physical therapy 45) in city C. Data was collected and the program was conducted from March 3 to June 14, 2014. Measurements employed were the ARCS model of motivational design, self-assertiveness, learning satisfaction, and interpersonal relationship. Data was analyzed through frequency statistics, descriptive statistics, and repeated measurement of one-way analysis of variance with the SPSS 19.0 program. Results: In this student question-centered lesson participants exhibited significant enhanced satisfaction in terms of learning motivation, learning satisfaction, self-assertiveness, behavioral assertiveness, general assertiveness, and sensibility regarding interpersonal relationships. Conclusion: The results suggest that student question-centered lessons are applicable to a variety of subjects. Also, for comparative purposes, a faculty-centered lesson will be undertaken.

• The Journal of Korean Academic Society of Nursing Education
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• v.17 no.3
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• pp.478-486
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• 2011

Purpose: The purpose of this study was to develop a guidebook for teachers about coping behavior education in emergency situations for elementary school students. Method: Dick and Carey's teaching model (1996) and Keller's ARCS theory (1985) was applied to develop this guidebook. Results: The contents consist of subjects, reference materials for teachers, a case study, and worksheets for students. The contents of the 5 units are as follows: 1)Identifying a dangerous situation around the school area and in school, 2)Coping tips in dangerous situations that can occur at school, 3)Prevention and coping method of sexual violence, 4)Coping method for natural disasters, and 5)First aid in emergency situations. The presented case study was a real case scenario and the worksheets contained various activities initiated by students. Conclusions: This guidebook can be an effective tool in coping education classes for emergency situations at elementary schools. The goal of the guideline book is reach as many elementary schools as possible.

• Child Health Nursing Research
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• v.15 no.2
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• pp.145-154
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• 2009

Purpose: The purpose of this study was to develop a guide book on safety education for teachers to use in education classes for elementary school students. Methods: Dick & Carey's teaching model and Keller's ARCS theory were used in the development of this guide book. Results: This guide book was developed for lower grade (1st$\sim$3rd) and higher grade (4th$\sim$6th) elementary school students. The content consisted of subjects, worksheets, content for teachers, statistical data, case studies, and a safety letter to the parents. The 10 subjects were as follows: "Importance of injury prevention", "Safety at home", "Accident prevention at school", "Violence prevention", "Vehicles safety", "Water safety", "Prevention of Fires & Burns", "Safety of Toys & home supplies", "Safety in Sports & Recreation activity", "Prevention of injury caused by animals". Statistical data was presented by graphs and case studies were presented of cases of real occurrences of accidents. Worksheets contain various activities for students. Safety letters were composed for each student's parents. Conclusion: This guide book presents effective material for safety education classes in elementary school and the authors hope it will be widely used in elementary schools.

• Journal of the Korea Society of Computer and Information
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• v.1 no.1
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• pp.147-158
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• 1996

This paper proposed a concurrency control structure based on specialized data flow graphs that was analysed a run-time concurrency control activity to be integrated with the task scheduler Data were viewed as flowing on the arcs from one node to another in a stream of discrete to tokens. The network that Is based upon the Entity-Relationship model, can be viewed a fixed problems used query tokens as a data flow graph. The performance was measured used in the various expriments compared the overall performance of the different concurrency control methods, DBFG (DataBase Flow graphs) scheduling had the knowledge to obtain better performance than 2PL in a distributed environment.

• Child Health Nursing Research
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• v.13 no.4
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• pp.495-505
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• 2007

Purpose: The purpose of this paper was to develop a CD program of applied logotherapy to improve the quality of life of adolescents with terminal cancer. Method: Keller's ARCS theory and a model for developing internet learning materials(Kang) was applied to develop this program comprised four distinct phases: planning, designing, development, and execution stages. Results: This program was entitled 'Finding treasures in my life' and consisted of 5 sessions and its educational contents were made up as follows: "Treasure One" is 'learning three natures of the human mind', "Treasure Two" is 'learning creative value as first method to find meaning of life', "Treasure Three" is 'learning experiential value as second method to find meaning of life', "Treasure Four" is 'learning attitudinal value as third method to find meaning of life', and "Treasure Five" is 'Becoming the master of my life'. The sub-menu was made up of 'Beginning', 'What is it?', 'Travelling'. 'Laughing Song', 'End'. Conclusions: This CD program applied logotherapy with flash animation technique as an emotional and spiritual nursing intervention program for easier and more scientific application in pediatric oncology and hospice area.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2515-2518
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• 2008

The vacuum interrupter (VI) is widely used in medium-voltage switching circuits due to its abilities and advantages as an environmental friendly circuit breaker. An understanding of the vacuum arc flow phenomena is very important for improving the performance of vacuum interrupter. In order to closely examine the vacuum arc phenomena, it is necessary to predict the magnetohydrodynamic (MHD) characteristics by the multidisciplinary numerical modeling, which is coupled with the electromagnetic and the thermal flow fields, simultaneously. In this study, we have investigated arc plasma constriction phenomena and an effect of AMF on the arc plasma with the high-current vacuum arcs for the cup-type AMF electrode by using a commercial finite element analysis (FEA) package, ANSYS. The simulation results applied with various AMFs and constant Joule heat generation show that strong axial magnetic field (AMF) permits the arc to be maintained in a diffused mode to a high-current vacuum arc. However, further studies are required on the two-way coupling method and radiation model for arc plasma in order to accomplish the advanced analysis method.