• Journal of Korean Institute of Industrial Engineers
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• v.41 no.5
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• pp.511-520
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• 2015

Inventory, cost, and the level of service are three interrelated key metrics that most supply chain organizations are striving to optimize. One way to achieve this goal is to create a simulation model to conduct sensitivity analysis and optimization on several different supply chain policies that can be implemented in actual operation. In this paper, a case of Xerox global supply chain modeling and analysis to assess several "what if" scenarios for the consumable policy safety stock is presented. The simulation model, combined with analytical cost model and optimization module, is used to optimize the policy safety stock level to achieve the lowest total value chain cost. It was shown quantitatively that the policy safety stock can be reduced, but it is offset by the inbound premium transportation cost to expedite supplies in shortage, and the outbound premium transportation cost to send supplies to customers via express shipment, requiring fine balance.

• Journal of Information Processing Systems
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• v.19 no.1
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• pp.130-138
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• 2023

The traffic flow in an urban area is affected by the date, weather, and regional traffic flow. The existing methods are weak to model the dynamic road network features, which results in inadequate long-term prediction performance. To solve the problems regarding insufficient capacity for dynamic modeling of road network structures and insufficient mining of dynamic spatio-temporal features. In this study, we propose a novel traffic flow prediction framework called shared spatio-temporal attention convolution optimization network (SSTACON). The shared spatio-temporal attention convolution layer shares a spatio-temporal attention structure, that is designed to extract dynamic spatio-temporal features from historical traffic conditions. Subsequently, the graph optimization module is used to model the dynamic road network structure. The experimental evaluation conducted on two datasets shows that the proposed method outperforms state-of-the-art methods at all time intervals.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.3
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• pp.119-124
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• 2017

Machining optimization using typical computer-aided manufacturing (CAM) software mainly depends on tool paths, and it is impossible to predict the behavior of material or cutting force. In this paper, cutting force analysis simulation is performed on the Unibody Case of a mobile phone with the aim of optimizing cutting-force-based machining using the Third Wave Systems' AdventEdge Production Module. Machining time after optimization was shortened by 42% for roughing compared to pre-optimization, and actual machining time was reduced by 36.8%. For finishing, machining time was reduced by 92%, and actual machining time was reduced around 90%. A surface roughness analysis found that the post-optimization surface roughness was $1.16{\mu}m$ Ra, compared to a pre-optimization value of $1.75{\mu}m$ Ra.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.4
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• pp.274-285
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• 2011

The supercavitating vehicle is an underwater vehicle that is surrounded almost completely by a supercavity to reduce hydrodynamic drag substantially. Since the cruise speed of the vehicle is much higher than that of conventional submarines, the drag force is huge and a buckling may occur. The buckling phenomenon is analyzed in this study through static and dynamic approaches. Critical buckling load and pressure as well as buckling mode shapes are calculated using static buckling analysis and a stability map is obtained from dynamic buckling analysis. When the finite element method (FEM) is used for the buckling analysis, the solver requires a linear static solver and an eigenvalue solver. In this study, these two solvers are integrated and a consolidated buckling analysis module is constructed. Furthermore, Particle Swarm Optimization (PSO) algorithm is combined in the buckling analysis module to perform a design optimization computation of a simplified supercavitating vehicle. The simplified configuration includes cylindrical shell structure with three stiffeners. The target for the design optimization process is to minimize total weight while maintaining the given structure buckling-free.

• Smart Media Journal
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• v.7 no.2
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• pp.40-46
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• 2018

The conventional CCTV surveillance system for preventing accidents and incidents misses 95% of the data after 22 minutes where one person monitors multiple CCTV. To address this issue, researchers have studied the computer-based intelligent video surveillance system for notifying people of the abnormal situation. However, because the system is involved in the problems of power consumption and costs, the intelligent video surveillance system based on embedded modules has been studied. This paper implements the intelligent video surveillance system based on embedded modules for detecting intruders, detecting fires and detecting loitering, falling. Moreover, the algorithm and the embedded module optimization method are applied to implement real-time processing. The intelligent video surveillance system based on embedded modules is implemented in Raspberry Pi. The algorithm processing time is 0.95 seconds on Raspberry Pi before optimization, and 0.47 seconds on Raspberry Pi after optimization, reduced processing time by 50.52%. Therefore, this suggests real processing possibility of the intelligent video surveillance system based on the embedded modules is possible.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.734-745
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• 2021

In order to achieve a good and competitive FPSO design, the building cost and the motion performances are the two most critical and conflicting KPIs to be considered. In this study, the author's previous work (Lee, et al., 2021) on the optimization of an FPSO's hull dimensions with 1800 MBBLs storage capacity at Brazil field was extended using a multi-objective parametric optimization with the hull steel weight and the operability which are closely related to the building cost and the operational cost during the lifetime, respectively. For the purpose of more realistic and practical FPSO design, the constraints related to crew comfort and the safe helicopter take-off and landing operation were newly added. Also, the green water on deck was calculated accurately to check the suitability of the designed freeboard height using a newly developed real-time calculation module for the relative wave elevations. With aids of this updated optimization formulation, we presented multiple optimal FPSO dimensions expressed as a Pareto set which aids FPSO designers to conveniently select the practical and competitive dimensions. The excellence of the developed approach was verified by comparing the optimization results with those of FPSOs dimensioned for operation at West Africa and Brazil field.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.789-796
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• 2012

To find the module sequence that makes correction rate optimal is the goal of this paper. The Hill-climbing algorithm was used in the experiment to analyze the performance of Korean Spelling Corrector. Given the wrong eojul set, We found the module sequence that shows correction rate of 96.41%. Because of the quite high correction rate, Hill-climbing is a practical method for our Spelling Corrector.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.347-348
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• 2006

This paper performed the basic study for developing the Photodynamic Therapy Equipment for medical treatment. The equipment have been manufactured by using the High Bright Light Emitting Diode and TLC5941 integrated circuit. As a result, 630nm Light Emitting Diode Module was made for the optimization of irradiation condition. And we confirmed the current change according to increase of the level of Light Emitting Diode Module.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.183-185
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• 2009

In this thesis, output voltage, current and power of solar module were classified by irradiation and module temperature from data of overall operating characteristics collected for one year in order to manage efficient photovoltaic generation system and deliver maximum power. In addition, from these data, correlations between irradiation, module temperature of photovoltaic cell and amount of power given by photovoltaic cell was quantitatively examined to deduce optimization of the design and construction of photovoltaic generation system. The results of this thesis can be summarized as follows. As I-Y characteristics according to a temperature range of 10$\sim$50[], the area of I-V characteristics were increased with an increase in temperature. Since this area corresponds to the power, output power is thought to have increased with temperature.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.186-188
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• 2009

In this thesis, output voltage, current and power of solar module were classified by irradiation and module temperature from data of overall operating characteristics collected for one year in order to manage efficient photovoltaic generation system and deliver maximum power. In addition, from these data, correlations between irradiation, module temperature of photovoltaic cell and amount of power given by photovoltaic cell was quantitatively examined to deduce optimization of the design and construction of photovoltaic generation system. The results of this thesis can be summarized as follows. As output power characteristics according to a temperature range of 10$\sim$50[], output power was increased with an increase in temperature. Since output power increases with temperature increase, the result corresponds well to the related equation on temperature and output power.