• Journal of the Korea Society for Simulation
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• v.18 no.4
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• pp.81-94
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• 2009

Research of reusability and variability design for embedded system development is insufficient. An embedded system should be designed to support new devices. If extensibility of embedded system is not considered, it is difficult to reconstruct. Currently, the development productivity and reusability of embedded system are very poor, and this will be cased about problems of increasing maintenance and development cost, and decreasing system quality such as software crisis. In this paper, we present framework of embedded system that address those problems of embedded system. We suggest a plug-in technique, based on reusability framework, which can support various devices dynamically. Also, we propose a dynamic Meta model which is base on plug-in technique.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.2724-2731
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• 2014

As the future national defense plan of government focus on advanced weapon system, military maintenance facility becomes more important. However, military maintenance facility has been managed by director's experience and simple mathematical calculation until now. Thus, the optimization for the management of military maintenance facility is suggested by more scientistic and logical methods in this study. The study follows the procedure below. First, simulation is designed according to the analysis of military maintenance facility. Second, independent variable and dependent variable are defined for optimization. Independent Variable includes the number of maintenance machine, transportation machine, worker in the details of military maintenance facility operation, and dependent variable involves total maintenance time affected by independent variable. Third, warmup analysis is performed to get warmup period, based on the simulation model. Fourth, the optimal combination is computed with evolution strategy, meta-heuristic, to enhance military maintenance management. By the optimal combination, the management of military maintenance facility can gain the biggest effect against the limited cost. In the future, the multipurpose study, to analyze the military maintenance facility covering various weapon system equipments, will be performed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.704-710
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• 2017

Our research team is developing a 6-DOF manipulator that is adequate for the narrow workspace of press forming processes. This paper addresses the task sequence optimization methods for the manipulator to minimize the task-finishing time. First, a kinematic model of the manipulator is presented, and the anticipated times for moving among the task locations are computed. Then, a mathematical model of the task sequence optimization problem is presented, followed by a comparison of three meta-heuristic methods to solve the optimization problem: an ant colony system, simulated annealing, and a genetic algorithm. The simulation shows that the genetic algorithm is robust to the parameter settings and has the best performance in both minimizing the task-finishing time and the computing time compared to the other methods. Finally, the algorithms were implemented and validated through a simulation using Mathworks' Matlab and Coppelia Robotics' V-REP (virtual robot experimentation platform).

• International conference on construction engineering and project management
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• 2015.10a
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• pp.540-543
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• 2015

Solar energy is one of the most important alternative energy sources which have been shown to meet high levels of heating and cooling demands in buildings. However, the efficiencies to satisfy these demands using solar energy significantly vary based on the characteristics of individual building. Therefore, this paper is focused on developing the methodology which can help to design optimal solar system for heating and cooling to be in cooperated within the existing buildings according to their load profiles. This research has established the Solar Heating and Cooling (SHC) system which is composed of collectors, absorption chiller, boiler and heat storage tank. Each component of SHC system is analyzed and made by means of Modelica Language and Pistache tool is verified the results. Sequential approximate optimization (SAO) and meta-models determined to 15 design parameters to optimize SHC system. Finally, total coefficient of performance (COP) of the entire SHC system is improved approximately 7.3% points compared to total COP of the base model of the SHC system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.856-864
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• 2019

The weapon-target assignment (WTA) problem is a matter of effectively allocating weapons to a number of threats. The WTA in a rapidly changing dynamic environment of engagement must take into account both of properties of the threat and the weapon and the effect of the previous decision. We propose a method of applying the Greedy Randomized Adaptive Search Procedure (GRASP) algorithm, a kind of meta-heuristic method, to derive optimal solution for a dynamic WTA problem. Firstly, we define a dynamic WTA problem and formulate a mathematical model for applying the algorithm. For the purpose of the assignment strategy, the objective function is defined and time-varying constraints are considered. The dynamic WTA problem is then solved by applying the GRASP algorithm. The optimal solution characteristics of the formalized dynamic WTA problem are analyzed through the simulation, and the algorithm performance is verified via the Monte-Carlo simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1652-1657
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• 2015

Recently the improvement in vehicle performance trend to increase in accordance with the weight of this part. Outer tie rod is small when compared to the other vehicle part by weight, but there is a need to reduce the weight of the outer tie rod in order to improve fuel efficiency of the vehicle. Therefore, from previous studies, a model of outer die rod is proposed using Design of Experiments and Meta model satisfying the buckling performance. Outer tie rod are manufactured through forging process, in this study, we compare the size of the forming load in accordance with the change in the moving speed through the die forging analysis of the outer tie rod on the basis of the actual molding process.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.2
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• pp.23-29
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• 2012

Existing pedestrian and evacuation models generally seek to find locally optimal solutions for the shortest or the least time paths to exits from individual locations considering pedestrian's characteristics (eg. speed, direction, sex, age, weight and size). These models are not designed to produce globally optimal solutions that reduce the total evacuation time of the entire pedestrians in a building when all of them evacuate at the same time. In this study, we suggest a globally optimal model for indoor pedestrian evacuation to minimize the total evacuation time of occupants in a building considering different distributions of them. We used the genetic algorithm, one of meta-heuristic techniques because minimizing the total evacuation time can not be easily solved by polynomial expressions. We found near-optimal evacuation path and time by expressing varying pedestrians distributions using chromosomes and repeatedly filtering solutions. In order to express and experiment our suggested algorithm, we used CA(cellular automata)-based simulator and applied to different indoor distributions and presented the results.

• The Journal of Advanced Prosthodontics
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• v.8 no.1
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• pp.53-61
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• 2016

PURPOSE. This study conducted an analysis of cost-effectiveness of the implant and conventional fixed dental prosthesis (CFDP) from a single treatment perspective. MATERIALS AND METHODS. The Markov model for cost-effectiveness analysis of the implant and CFDP was carried out over maximum 50 years. The probabilistic sensitivity analysis was performed by the 10,000 Monte-Carlo simulations, and cost-effectiveness acceptability curves (CEAC) were also presented. The results from meta-analysis studies were used to determine the survival rates and complication rates of the implant and CFDP. Data regarding the cost of each treatment method were collected from University Dental Hospital and Statistics Korea for 2013. Using the results of the patient satisfaction survey study, quality-adjusted prosthesis year (QAPY) of the implant and CFDP strategy was evaluated with annual discount rate. RESULTS. When only the direct cost was considered, implants were more cost-effective when the willingness to pay (WTP) was more than 10,000 won at $10^{th}$ year after the treatment, and more cost-effective regardless of the WTP from $20^{th}$ year after the prosthodontic treatment. When the indirect cost was added to the direct cost, implants were more cost-effective only when the WTP was more than 75,000 won at the $10^{th}$ year after the prosthodontic treatment, more than 35,000 won at the $20^{th}$ year after prosthodontic treatment. CONCLUSION. The CFDP was more cost-effective unless the WTP was more than 75,000 won at the $10^{th}$ year after prosthodontic treatment. But the cost-effectivenss tendency changed from CFDP to implant as time passed.

• Quality Improvement in Health Care
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• v.30 no.1
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• pp.132-152
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• 2024

Purpose: This study aimed to identify and evaluate interprofessional education (IPE) interventions for healthcare professional students in East Asian countries. Methods: The reporting of this study followed the Preferred Reporting Items of Systematic Reviews and Meta-Analysis guidelines. A literature search was conducted using seven electronic databases: PubMed, EMBASE, CINAHL, Scopus, Web of Science, ERIC, and ProQuest Dissertations & Theses Global. Joanna Briggs Institute Critical Appraisal Checklists were also used to appraise the quality of the included studies. The outcomes of IPE interventions were classified based on a modified Kirkpatrick model. Results: This review included 30 studies predominantly conducted in Singapore, South Korea, and Taiwan. The prevalent research design was a one-group pre-posttest design, and most IPE interventions occurred as single events. Approximately 70% of the studies involved students from two healthcare professions, mainly nursing and medicine. Simulations, group discussions, and lectures have emerged as the most common teaching methodologies, with almost half of the studies leveraging a combination of these techniques. The IPE content primarily focused on interprofessional teamwork, communication, and clinical patient care situations; these included the management of septic shock. The effectiveness of the IPE interventions was mainly evaluated through self-reported measures, indicating improvements in attitudes, perceptions, knowledge, and skills, aligning with Level 2 of the modified Kirkpatrick model. Nonetheless, the reviewed studies did not assess changes in the participants' behavior and patient results. Conclusion: IPE interventions promise to enhance interprofessional collaboration and communication skills among health professional students. Future studies should implement rigorous designs to assess the effectiveness of IPE interventions. Moreover, when designing IPE interventions, researchers and educators should consider the role of cultural characteristics in East Asian countries.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.107-118
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• 2022

The social need for stable hydrogen storage technologies that respond to the increasing demand for hydrogen energy is increasing. Among them, underground hydrogen storage is recognized as the most economical and reasonable storage method because of its vast hydrogen storage capacity. In Korea, low-depth hydrogen storage using artificial protective structures is being considered. Further, establishing corresponding safety standards and ground stability evaluation is becoming essential. This study evaluated the hydro-mechanical behavior of the ground during a hydrogen gas leak from a low-depth underground hydrogen storage facility through the HM coupled analysis model. The predictive reliability of the simulation model was verified through benchmark experiments. A parameter study was performed using a metamodel to analyze the sensitivity of factors affecting the surface uplift caused by the upward infiltration of high-pressure hydrogen gas. Accordingly, it was confirmed that the elastic modulus of the ground was the largest. The simulation results are considered to be valuable primary data for evaluating the complex analysis of hydrogen gas explosions as well as hydrogen gas leaks in the future.