• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.9
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• pp.1546-1554
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• 2003

Efficient layout in a fixed work volume reduces build time when multiple parts are built at once in stereolithography systems. An efficient algorithm is developed for 3D layout planning. And it reduces build time and increases efficiency of SLA system. Genetic algorithm is implemented to locate as many parts as possible in the fixed work volume. A 3D collision detection algorithm, k-DOPs Tree, is implemented for the fast evaluation of a layout plan.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.73-82
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• 2012

Currently, R&D investment of government is increased dramatically. However, the budget of the government is different depending on the size of ministry and priorities, and then it is difficult to obtain consensus on the budget. They did not establish decision support systems to evaluate and execute R&D budget. In this paper, we analyze factors affecting research funds by linear regression and decision tree analysis in order to increase investment efficiency in national research project. Moreover, we suggested strategies that budget is estimated reasonably.

• Journal of Korean Society of Rural Planning
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• v.7 no.2 s.14
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• pp.33-40
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• 2001

The purpose of this paper is on identifying spatial structure of Palwang and Taechon village and dealing with restoration direction of village spatial structure and village groves. The results are as follows. It was identified that the standing stone for penis form is not standing stone for praying son but complementing that for enforcing enclosed function of enclosing village groves. It was considered that village entrance and entrance road, village grove of Taechon village must be restored for being identified as standing stone of penis form of spatial structure of village. It was considered that the above is essential to connect with ecotourism of Sunchang-gun region. It was identified that Palwang village grove is very good in conservation state, but Taechon village grove has been destructed mostly by various development. It was identified that Palwang village grove is high in species diversity and in scare value as mixed forest, landscape value. The dominent tree of Palwang village was Pinus densiflora and that of Taechon was Salix glandulosa. Salix glandulosa was used pavilion tree, main tree in both village. It was identified that Carpinus tschonoskii is showing the most rapid growth in tree height and Salix glandulosa is showing the most rapid growth in tree breadth diameter of all kind of tree. It was considered that Pinus densiflora was planted first of all and deciduous trees were complemented later. It was considered that simple forest of Pinus densiflora has been changed into mixed forest by artificial affect in the long term. It was considered that Salix glandulosa in Palwang village grove must be indicated as legal protection tree according to present criteria of protection tree selection in Korea. And it is considered desirable that standing stone of penis form and village grove in Palwang village must be indicated unitedly as cultural conservation element.

• The Journal of Korea Robotics Society
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• v.5 no.4
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• pp.332-338
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• 2010

This paper presents a study of path-planning method for AGV(automated guided vehicle) based on path-tracking. It is important to find an optimized path among the AGV techniques. This is due to the fact that the AGV is conditioned to follow the predetermined path. Consequently, the path-planning method is implemented directly affects the whole AGV operation in terms of its performance efficiency. In many existing methods are used optimization algorithms to find optimized path. However, such methods are often prone with problems in handling the issue of inefficiency that exists in system's operation due to inherent undue time delay created by heavy load of complex computation. To solve such problems, we offer path-planning method using modified binary tree. For the purpose of our experiment, we initially designed a AGV that is equiped with laser navigation, two encoders, a gyro sensor that is meant to be operated within actual environment with given set of constrictions and layout for the AGV testing. The result of our study reflects the fact that within such environments, the proposed method showed improvement in its efficiency in finding optimized path.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.601-602
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• 2006

The primary role of MRP(Material Requirement Planning) is to make a production plan so that we have an exact quantity of right materials on needed time at right place. But the ignorance on capacity constraints makes some problems whenever production schedule is established. To increase the performance of MRP system, a novel approach which is based on new input data structure is suggested. The new input data structure includes all the information about Material BOM, Routing and resource data so that we can easily examine the usage of resources and generate higher performance production plans.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.200-214
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• 2014

Technology planning is becoming increasingly important with the rapid development and decline of technology. Technology roadmapping is a tool used to select whether the specific technique of technology planning should pursue which technology and in which time. This technology is important to secure the uncertain future since it will provide a method that is able to share the goals and strategies between organizations. Therefore, technology tree in the planning stage of the problem would be a very useful tool. In this study, both domestic and international technology tree application cases were analyzed to be able to derive a plan for ensuring that the research performed and the requirements are met for the future development and implementation of a convergence portal system. The six major systems that aim at water hazard information platform are basic information providing system, analysis information providing system, water disaster theme providing system, national disaster information system, water disaster augmented reality system and open information platform system. General standardized core technologies corresponding to the needed functions in each target system are derived through brainstorming, and classified according to the technology field to derive the technology tree.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.5
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• pp.29-36
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• 2002

In the maintenance and retrofit planning of a bridge system, the optimal strategy for inspection and repair are suggested by minimizing the expected total life-cycle cost, which includes the initial cost, the costs of inspection, repair, and failure. Degradation of seismic performance is modeled by using a damage function. And failure probability is computed according to the degree of damage detection by random vibration theory and the event tree analysis. As an example to illustrate the proposed approach, a 10-span continuous bridge structure is used. The numerical results show that the optimum number of the inspection and the repair are increased, as the seismic intensity is increased and the soil condition of a site becomes more flexible.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.699-711
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• 2014

This study was carried out to analyze water suspension in the water supply system through fault tree analysis. And quantitative factors was evaluated to minimize water suspension. Consequently the aim of this study is to build optimal planning by analyzing scenarios for water suspension. Accordingly the fault tree model makes it possible to estimate risks for water suspension, current risks is $92.23m^3/day$. The result of scenario analysis by pipe replacement, risks for water suspension was reduced $7.02m^3/day$ when replacing WD4 pipe. As a result of scenario analysis by water district connections, the amount of risk reduction is maximized when it is connecting to network pipe of D Zone. Therefore, connecting to network pipe for D Zone would be optimal to reduce risk for water suspension.

• Korean Journal of Childcare and Education
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• v.18 no.5
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• pp.79-99
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• 2022

Objective: This study was conducted to examine the significant factors affecting media device addiction using the data mining technique for large-scale data from the Panel Study on Korean Children Survey (PSKC). The PSKC data of this study were gathered from the elementary school students in their 10th survey (1,286 3rd grade students). Methods: The SPSS 21.0 program was used for data mining decision tree analysis, and the results are as follows. Results: First, the most important predictor of media device addiction was planning-organization which was among the sub-factors of executive function. Second, as a result of the decision tree analysis, the children with the highest probability of addiction to media devices were ones that had difficulties in planning and organizing, had mothers with a permissive parenting attitude felt difficulties in controlling behavior, and were alone at home for more than two hours a day without any adult supervision. Conclusion/Implications: The results of this study can help guide the direction of future research related to children's addiction to media devices by exploring and analyzing factors that significantly affect children's addiction to media devices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1392-1398
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• 2008

This paper presents a Petri Net (PN) based disassembly sequence planning model with precedence operations. All feasible disassembly sequences are generated by a disassembly tree and a disassembly sequence is determined using the disassembly precedence and disassembly value matrix, The precedence of disassembly operations is determined through a disassembly tree and the value of disassembly is induced by economic analysis in the end-of-life phase. To solve the disassembly sequence planning model with precedence operations, a heuristic algorithm based on PNs is developed. The developed algorithm generates and searches a partial reachability graph to arrive at an optimal or near-optimal disassembly sequence based on the firing sequence of transitions of the PN model. A refrigerator is shown as an example to demonstrate the effectiveness of proposed model.