• Proceedings of the Korea Society for Simulation Conference
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.468-476
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• 2001

The ROK TRANSCOM is trying to establish a concrete wartime sealift operation plan. But there are many problems to be solved for setting up the plan. The most serious problem is to procure war materiel to be shipped in U.S.A and next one is to determine the number of sealift assets and to allocate them. The process of sealift operation can be described as follows. Before the order of vessel mobilization, all vessels appointed for activation would be scattered in worldwide in the state of Beaded or unloaded. After the order of vessel mobilization, vessels would go to SPGE(seaport of embarkation) to load war materiel. Some loaded ships should offload the commercial cargo to the near port as soon as they are activated, before they would go to SPOE. All vessels would load procured materiel in SPOE and then go to SPOD(seaport of debarkation). They would offload war materiel in SPOD and then go back to SPOE to load war materiel again. We will simulate this process using ARENA(1), evaluate the sealift capability of ROK and find omit problems of the sealift plan. This model ultimately evaluates the sealift capability and provides planners with critical information far establishing and correcting the plan. This study can also provide military planners with a flexible and accessible decision support tool to provide advance planning under a variety of conditions on the sealift capability. The military planner is expected to make use of this model as a standard for establishing effective and concrete sealift operation in the near future. We can conclude how procurement capability significantly affects the result of sealift operation through this model. We could decide the appropriate levee of sealift asset such as the number of vessels and the number of available berth. So we could allocate effectively the resources for completing the sealift operation within the TGT(Target) time.

• Journal of Food Hygiene and Safety
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• 제27권2호
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• pp.109-116
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• 2012

The study indicated that antimicrobial activity about gram positive and gram negative bacteria of ginger-oleoresin(GO) extract with the condition of ethanol and supercritical fluid extractions. As the concentration of extraction increases, the clear zone of GO ethanol extract also increased dependently. This led the antimicrobial activity of gram positive bacteria to take bigger place than gram negative bacteria especially in Listeria monocytogenes. There was a high antimicrobial activity in E-III treatment where the ratio of the ginger powder extract to ethanol extraction was 1:6. It was quite effective to treat the antimicrobial activity of GO ethanol extract under $80^{\circ}C$ and there was not big difference in the intervals which were the extraction time - 1 to 7 hours. The antimicrobial activity of supercritical fluid extract seemed to take the biggest place in Listeria monocytogenes. From the supercritical fluid extract, it was shown the strong ability of antimicrobial activity in the condition with 100 bar $35^{\circ}C$, 250 bar $35^{\circ}C$ and 250 bar $65^{\circ}C$. Furthermore, according to the case of solvent extract, there was not any significant difference in the antimicrobial activity with condition of extraction. However, there was significant antimicrobial activity in E-III treatment of 100 bar and 500 bar of extraction pressure, and $35^{\circ}C$ and $65^{\circ}C$ of extraction temperature.

• Journal of Convergence for Information Technology
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• 제9권3호
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• pp.128-133
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• 2019

The purpose of this study is to verify whether the data measured by the researcher and the smart shoe sensor data are the same or similar by performing the 6 - minute walking test and time up and go test after putting smart shoes on a normal person. Ten normal adult males participated. After wearing smart shoes, they performed a 6-minute walk test and a time up and go test. The results of this experiment show that the accuracy of the current sensor is high. The difference in the distance of the 6-minute walking test is that the difference is because the turning point, which is not calculated in the actual 30-m track, measures the distance. From this point of view, it can be seen that smart shoes measure more accurate distance and it is expected that various tests will be possible through smart sensors.

• Journal of the Korea Society for Simulation
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• 제13권4호
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• pp.1-16
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• 2004

The modelling and simulation of the activation process for the heart system is meaningful to understand special excitatory and conductive system in the heart and to study cardiac functions because the heart activation conducts through this system. This thesis proposes two dimensional cellular automaton(CA) model for the activation process of the myocardium and conducted simulation by means of discrete time and discrete event algorithm. In the model, cells are classified into anatomically similar characteristic parts of the heart and each of cells has a set of cells with preassigned properties. Each cell in this model has state variables to represent the state of the cell and has some state transition rules to change values of state variables executed by state transition function. The state transition rule is simple as follows. First, the myocardium cell at rest stay in passive state. Second, if any one of neighborhood cell in the myocardium cell is active state then the state is change from passive to active state. Third, if cell's state is an active then automatically go to the refractory state after activation phase. Four, if cell's state is refractory then automatically go to the passive state after refractory phase. These state transition is processed repeatedly in all cells through the termination of simulation.

• Journal of Korea Multimedia Society
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• 제9권1호
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• pp.101-108
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• 2006

Developing a network game that is serviced on the internet requires a lot of work, time and manpower. Therefore, it is important to design a game in such a way so that existing design codes could be used. The database for the multi-player network game is accessed from many clients. To manage the resource effectively, it is required to design the APIs to be minimized the database access and to be dealt with the related data efficiently. For this, it is needed to apply the object-oriented design for the related software modules. In the paper, we propose the design patterns of GoF to implement the APIs thatis needed to deal with the database resource. The database design through the analysis of some game's GUI has the advantage to create the optimized schema set more quickly, because it minimize the review step and the modification step of the database design generally. In addition, we apply to the design patterns of GoF for the APIs design of the server-side database. These reduce the times of the program call between the game server and the database server. These also make easily the maintenance for the already developed APIs, and it makes easily the addition of new APIs.

• Journal of Power Electronics
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• 제12권5호
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• pp.715-722
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• 2012

New discrete time domain models for the peak current controlled (PCC) power LED drivers in continuous conduction mode include for the first time the effects of the time delay in the pulse-width-modulator. Realistic amounts of time delay are found to have significant effects on the average output LED current and on the critical inductor value at the boundary between the two conduction modes. Especially, the time delay can provide an accurate LED current for the PCC buck converter with a wide input voltage. The models can also predict the critical inductor value at the mode boundary as functions of the input voltage and the time delay. The overshoot of the peak inductor current due to the time delay results in the increase of the average output current and the reduction of the critical inductor value at the mode boundary in all converters. Experimental results are presented for the PCC buck LED driver with constant-frequency controller.

• Physical Therapy Rehabilitation Science
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• 제9권3호
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• pp.178-183
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• 2020

Objective: This study conducted in order to investigate the correlations between fall experience, balance, mobility, and confidence. We examined the difference between fall experience, and Berg Balance Scale (BBS), Timed-Up-and-Go test (TUG), Tinetti balance assessment (Tinetti balance [TiB], Tinetti gait [TiG]), and Activities-specific Balance Confidence (ABC) scale scores to see how fall experience, balance, mobility, and confidence of the persons with stroke affects their balance. Design: Cross-sectional study. Methods: Forty-one subjects participated in this study. The BBS includes 14 items, consisting of a 5-point scale from 0 to 4, totaling up to 56 points. The Timed Up and Go-Alone (TUGA) was used to measure the average time to take a 3 m round-trip by getting up and down from a 46-cm high chair with an armrest on a flat floor. The Timed-Up-and-Go-Cognitive (TUGC) was performed by counting backwards and the Timed Up and Go-Manual (TUGM) is performed by holding a cup full of water. The total score for the TiB is 16 points, and the TiG is 12 points, making a total of 28 points. There are 16 items total for the ABC scale. Results: According to the fall experience, BBS, the TUGA and TUGC values were significantly higher in the inexperienced group compared to the experienced group (p<0.05). The number of falls was significantly correlated with BBS, TUGA, TUGC, TUGM, TiB, TiG, TiB+TiG (p<0.05). Conclusions: This study supports that falls experience is strongly related to balance, mobility, and confidence. Optimal balance training programs for fall prevention is still insufficient and must be developed.

• Korean Management Science Review
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• 제18권1호
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• pp.29-39
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• 2001

Traditionally, companies have been concerned with making an investment decision either to go now or never to go forever. However, owing to the development of the theory of options pricing in a financial investment field and its introduction to the appraisal of real investments in these days, we are now partially allowed to derive the value of a managerial flexibility of real investment projects. In this paper, we derived a general mathematical model to price the option value of real investment projects assuming that they have only one-period of time under which uncertainty exists. This mathematical model was developed based on the opportunity cost concept. We will show a simple numerical example to illustrate how the mathematical model works comparing it with the existing models.

• Polymer(Korea)
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• 제37권2호
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• pp.162-166
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• 2013

Graphene-coated polymer particles have attracted research interests due to their emerging applications derived from their controlled structure and morphology. To control the properties of graphene oxide (GO)-polystyrene (PS) composite particles, the adsorption time and instantaneous adsorption conditions were investigated by varying their mixing method. Polystyrene particles prepared by emulsion polymerization were modified to have positive surface charge by adsorption of polyethylene imine (PEI) on the surface of PS particles. GO prepared by the chemical exfoliation method had negative surface charge from the oxygenated groups. The adsorption of the negatively charged GOs onto the positively charged PS particles was successfully completed, and it was found that a longer adsorption time and a greater difference in the instantaneous relative concentration led PS-GO particles to have more homogeneously coated surfaces without aggregation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.6-11
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• 1994

For a safety supervision, watching a restricted area so that no one go there is very important. This has been mostly accomplished by people. They keep an eye on many monitors at onece for a long time. It, however, is too simple and boring to concentrate it for a long time. So it's worth while to construct a watching system by image processing. And the system we made is now actually working at a certain hydroelectric power plant and some other restricted areas in Japan.