• Journal of the Korea Society for Simulation
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• v.19 no.4
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• pp.291-299
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• 2010

As recent advances in science, technology and performance requirements of the weapons system are getting highly diversified and complex, the performance requirements also get stringent and strict. Moreover, the weapons system should be intimately connected with other systems such as watchdog system, command and control system, C4I system, etc. However, a tremendous amount of time, cost and risk being spent to acquire new weapons system, and not being diminished compared to the rapid pace of its development speed. Defense Modeling and Simulation(M&S) comes into the spotlight as an alternative to overcoming these difficulties as well as constraints. In this paper, we propose the development process of virtual test framework based on the synthetic environment as a tool to analyze the effectiveness of the weapons system of underwater engagement model. To prove the proposed concept, we develop the test-bed of virtual test using Delta3D simulation engine, which is open source S/W. We also design the High Level Architecture and Real-time Infrastructure(HLA/RTI) based Federation for the interoperation with heterogeneous simulators. The significance of the study entails (1)the rapid and easy development of simulation tools that are customized for the Korean Theater of War; (2)the federation of environmental entities and the moving equations of the combat entities to manifest a realistic simulation.

• Land and Housing Review
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• v.14 no.3
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• pp.17-36
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• 2023

This research aims to investigate the socio-demographic, financial, and housing statuses of young married couples in Chonsei housing and to analyze the determinants of their residential environment quality and housing expenditure in four districts - Seoul and Gyeonggi-Incheon Area(GIA) of the Seoul Metropolitan Area(SMA), and metropolises and non-metropolises of non-SMA. From the 2020 Korean Housing Survey(KHS), this cross-sectional analysis examined a sample of 691 households, and the findings revealed that most were headed by college-educated, salaried male workers aged 31 years old. While childless dual-earner couples were common in Seoul, single-income families of three were prevalent in non-SMA. The financial status of the couples in Seoul was a lot better than in the other three areas, particularly much higher in Chonsei deposit and total asset value. Further, many lived in a three-bedroom apartment unit sized 60m² and bigger, using a Chonsei loan. Regardless of areas, almost all the households spent a very low portion of their living expenses and income on housing costs. However, dual-earner families positively increased borrowing capacity, which improves the household's financial position that is likely to lead to equity increment in a volatile asset market in the long run. The statistical results indicated that residential environment assessment was influenced by neighborhood quality and housing expenditure was affected by housing size in Seoul, urban amenities in GIA and householder's gender in non-metropolises. Thus, this research proposes that strong measures be considered to mitigate housing inequality embedded in geographical and socio-economic disparities.

• The Korean Journal of Franchise Management
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• v.5 no.1
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• pp.109-141
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• 2014

Recently, the interests of consumers in firms that implement the social commitment activities have been consistently growing. Consumers' evaluation about the level of corporate social responsibility(CSR) can affect the overall image for product or service of corporation. This recent changes make a marketer to have to consider direct and indirect effects of CSR efforts on the market performance. This phenomena is also found in the franchise industry. The importance of CSR is more critical rather than other industries since each franchisor should care franchisees as well as end users. Franchisors' execution of CSR could increase satisfaction of end user through consonance of activities provided by franchisees. However most franchisor stay in focusing on the traditional CSR activities. Therefore, this study aims to enhance the understanding the CSR in franchise and provide the phase model of CSR development for general firms including franchise. After diagnosis the firms with the proposed model, the study found many franchisors have huge gap between current CSR activities and higher level of CSR policies that franchisor have to make facing. This study call franchisors to reduce this gap by implementing new CSR efforts. If they answer for this calling, franchise industry could leap for making the best practice of creating shared value with other stakeholders.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5A
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• pp.861-872
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• 2006

The element free Galerkin method is extended by the local partition of unity method to model the cohesive cracks in two dimensional continuum. The shape function of a particle whose domain of influence is completely cut by a crack is enriched by the step enrichment function. If the domain of influence contains a crack tip inside, it is enriched by a branch enrichment function which does not have the LEFM stress singularity. The discrete equations are obtained directly from the standard Galerkin method since the enrichment is only for the displacement field, which satisfies the local partition of unity. Because only particles whose domains of influence are influenced by a crack are enriched, the system matrix is still sparse so that the increase of the computational cost is minimized. The condition for crack growth in dynamic problems is obtained from the material instability; when the acoustic tensor loses the positive definiteness, a cohesive crack is inserted to the point so as to change the continuum to a discontiuum. The crack speed is naturally obtained from the criterion. It is found that this method is more accurate and converges faster than the classical meshless methods which are based on the visibility concept. In this paper, several well-known static and dynamic problems were solved to verify the method.

• 한국노년학
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• v.31 no.2
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• pp.259-276
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• 2011

If frail elderly could use home care services adequately, quality of their life might improve and their costs of service would be decreased. The purpose of this study is to examine the factors on institutionalization of elderly using home care services in Korean long-term care insurance system. This study used the data of '2009 satisfaction survey of Korean long-term care system'. The survey proceeded using sampling data by region, level of long-term care need, and insurance type among beneficiaries from August 2009 to September 2010. The onset dates of institutionalization of 1,230 participants were ascertained from long-term care insurance claim data. This study calculated hazard ratio through Cox Proportional Hazard Model. The results showed that if elderly using home care services suffer a fracture, the hazard ratio of institutionalization is higher significantly. Although not significant, if older persons have more items of damaged cognitive functions, the hazard ratio of institutionalization is higher. The results have policy implications to supplement of home care service system and postpone institutionalization of elderly.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.4
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• pp.253-260
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• 2023

The germanium-68/gallium-68 (⁶⁸Ge/⁶⁸Ga) generator has high spatial utilization and requires little maintenance, making it economical and easy to produce. Thus, the frequency of use of ⁶⁸Ga radiopharmaceuticals is rapidly increasing worldwide. Therefore, this study attempted to develop an automated synthesizer for the routine clinical application of ⁶⁸Ga radiopharmaceuticals. The automated synthesizer was based on a fixed tubing system and the structure was designed after adjusting the position of the parts to reflect the synthesis method. Using various components that can be supplied in Korea, the automated synthesizer was manufactured at a much lower price cost than that of a commercialized automated synthesizer sold by companies. ⁶⁸Ga-DOTA-[Tyr3]-octreotide (⁶⁸Ga-DOTATOC) was synthesized to evaluate the performance of the automated synthesizer. ⁶⁸Ga-DOTATOC could be synthesized with about 65% of non-decay corrected yield, and the synthesized ⁶⁸Ga-DOTATOC met all quality control standards. We have synthesized ⁶⁸Ga-DOTATOC more than 100 times, and only faced a few problems caused by mechanical errors. In this study, we successfully developed a simple automated synthesizer for ⁶⁸Ga radiopharmaceuticals with high reproducibility. As various ⁶⁸Ga radiopharmaceuticals have recently been developed, it is expected that the automated synthesizer developed in this study will be useful for routine clinical use.

• Journal of the Korean Applied Science and Technology
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• v.40 no.4
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• pp.710-723
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• 2023

The purpose of this study is to investigate the effect on the revisit intention and recommendation intention on the golf course selection attribute factors of Chinese golf course users using IPA. In order to carry out this study, a survey was conducted on 388 Chinese golfers, data processing and IPA analysis were conducted, and the following conclusions were obtained. First, the importance of the selection attribute was the highest in employee etiquette, and the price of restaurants and food and beverage was the highest in satisfaction. Second, as a result of the IPA matrix analysis, there were 8 selection attributes for continuous maintenance, 14 for concentration improvement, 5 for low priority, and 3 for excessive effort avoidance. Third, cost, accessibility, course facilities, auxiliary facilities, caddy expertise, and satisfaction with user management were found to affect both revisit and recommendation intentions. Since this study was limited to Chinese golfers, there may be differences in comparing the results with previous studies conducted in other countries on golf culture. Therefore, studies considering cultural diversity should be conducted in the future.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.142-156
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• 2024

The transition to electric vehicles is a crucial step toward achieving carbon neutrality in the transportation sector. Adequate charging infrastructure at residential locations is essential. In South Korea, the predominant form of housing is multifamily dwellings, necessitating the provision of public charging stations for numerous residents. Although the government mandates the availability of charging facilities and designated parking areas for electric vehicles, it bases the supply of charging stations solely on the number of parking spaces. Slow chargers, mainly 3.5kW charging outlets and 7kW slow chargers, are commonly used. While the former is advantageous for installation and use, its slower charging speed necessitates the coexistence of both types of chargers. This study presents an optimization model that allocates chargers capable of meeting charging demands based on daily driving distances. Furthermore, using the metaheuristic algorithm Tabu Search, this model satisfies the optimization requirements and minimizes the costs associated with charger supply and usage. To conduct a case study, data from personal travel surveys were used to estimate the driving distances, and a hypothetical charging scenario and environment were set up to determine the optimal supply of 22 units of 3.5kW charging outlets for the charging demands of 100 BEVs.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.2
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• pp.82-90
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• 2024

It often happens that a removable partial denture needs to be repaired due to tissue changes in the remaining alveolar ridge, fracture of the denture, or fracture of the abutment tooth. There are several advantages to retrofitting a customized surveyed crown under the existing RPD. Retrofitting a crown to the RPD decreases the economic burden to the patient and avoids the need for several appointments to fabricate a new RPD. It is difficult for artificial teeth used to repair dentures due to fractured natural teeth to have a shape similar to that of natural teeth, and to repair aesthetic artificial teeth, it is necessary to manufacture customized artificial teeth similar to the shape of each patient's teeth. Recently, CAD/CAM technology has been used to fabricate customized prosthetics on existing RPD to achieve high retention and fitness accuracy, and by manufacturing customized artificial teeth, more aesthetic and harmonious artificial tooth repair is possible. This is a case in which a denture was repaired using a digital method to fabricate a customized prosthesis on an existing partial denture and customized artificial teeth that mirrored the adjacent dentition, saving time and cost, simplifying the process, and achieving aesthetically and functionally satisfactory results.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.3
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• pp.212-221
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• 2011

Wastewater treatment plants (WWTPs) are required to meet the reinforced discharge standards which are differentiated as 0.2, 0.3 and 0.5 mg-TP/L for the district I, II and III, respectively. Although most of WWTPs are operating advanced biological phosphorus removal system, the supplementary phosphorus treatment facility using chemical addition should be required almost at all WWTPs. Therefore, water quality data from several exemplary full-scale plants operating phosphorus treatment process were analyzed to evaluate the reliability of removal performance. Additionally, a series of jar tests were conducted to find optimal coagulants dose for phosphorus removal by chemical precipitation and to describe characteristics of the reaction and sludge production. Chemical costs and the increasing sludge volume in physicochemical phosphorus removal process were estimated based on the results of jar tests. The minimum coagulant (aluminium sulfate and poly aluminium chloride) doses to keep TP concentration below 0.5 and 0.2 mg/L were around 25 and 30 mg/L (as $Al_2O_3$), respectively, in the mixed liquor of activated sludge. In the tertiary treatment facility, relatively lower coagulant doses of 1/12~1/3 the minimum doses for activated sludge were required to achieve the same TP concentrations of 0.2~0.5 mg/L. Increase in suspended solids concentration due to chemical precipitates in mixed liquor was estimated at 10~11%, compared to the concentration without chemical addition. When coagulant was added into mixed liquor, chemical (aluminium sulfate) cost was estimated to be 4~10 times higher than in secondary effluent coagulation/separation process. Sludge production to be wasted was also 4~10 times higher than secondary effluent coagulation/separation process.