• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.25-37
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• 2024

The objective of this study was to create intelligent rail robots that are optimized for facility management and implement digital twin systems for smart road tunnel management. An autonomous surveillance system is formed by combining the sensing platform consisting of railing robots, fixed cameras and environmental detection sensors with the digital twin data platform technology for tunnel monitoring and early fire suppression. In order to develop mobile rail robots for fire extinguishing, we also designed and manufactured robots for extinguishing & monitoring and fire extinguishing devices, and then we examined the optimization of all parts. Our next step was to build a digital twin for road tunnel management by developing continuous image display system and implementing 3D modeling. After constructing prototypes, we attempted simulations by configuring abnormal symptom scenarios, such as vehicles fires. This study's proposal proposes high-accuracy risk prediction services that will enable intelligent management of risks in the tunnel with early response at each stage, using the data collected from the intelligent rail robots and digital twin systems.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.9-18
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• 2009

This paper proposes a Ubiquitous Henhouse Monitoring System (UHMS) that can not only monitor henhouse's conditions and raising environments, but also control the henhouse remotely by using sensor network technology. The system consists of three layers. The physical layer connects sensors with facilities. The middleware layer processes and manages data collected from the physical layer. And the application layer provides the user with the user requested services. The system provides a real-time monitoring service, a facility controlling service, an expert service, a consumer safety service, and a mobile message service via interacting with components of each layer. Finally, a henhouse model is defined and the relevant system components and the application GUIs are implemented.

• Journal of the Korean Operations Research and Management Science Society
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• v.4 no.1
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• pp.51-67
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• 1979

This paper considers the problem of determining an optimal dynamic operating policy for a two-stage tandem queueing service system in which the service facilities (or stages) can be operated at more than one service rate. At each period of the system's operation, the system manager must specify which of the available service rates is to be employed at each stage. The cost structure includes an operating cost for running each stage and a service facility profit earned when a service completion occurs at Stage 2. We assume that the system has a finite waiting capacity in front of each station and each customer requires two services which must be done in sequence, that is, customers must pass through Stage 1 and Stage 2 in that order. Processing must be in the order of arrival at each station. The objective is to minimize the total discounted expected cost in a two-stage tandem queueing service system, which we formulate as a Discrete-Time Markov Decision Process. We present analytical and numerical results that specify the form of the optimal dynamic operating policy for a two-stage tandem queueing service system.

• Korean Management Science Review
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• v.19 no.1
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• pp.29-38
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• 2002

Due to the rapid increase In the Internet traffic volume, ISPs are faced with the definite need of the expansion of server capacity. In order to Provide prompt services for customers and still prevent excessive facility cost, it is critical to determine the optimum level of internet server capacity. The purpose of this Paper is to provide a simple but effective strategy on the expansion of servers capacity according to the increase in internet traffic. We model an internet server as an M/G/m/m queueing system and derive an efficient method to compute the loss probability which, In turn, Is used as a basis to determine proper server capacity. The Process of estimating the traffic parameter values at each server based on log data analysis is also given. All the procedures are numerically demonstrated through the process of analyzing actual log data collected from a game company.

• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.530-537
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• 2022

Tug services are essential services to ensure port safety. However, due to the relatively low barrier to entry into the tug service market, the number of service companies has increased, which has led to growing concerns about excessive competition among companies and poor service quality. To solve these problems, it is necessary to prepare a service quality evaluation system, but full-fledged implementation remains far away. The purpose of this study is to develop a tug service quality evaluation model that can be practically applied. To this end, an evaluation model consisting of two major categories, eight middle categories, and 25 detailed evaluation indicators was developed through a literature review, case studies, and expert interviews. AHP analysis is also conducted to derive the relative importance of the evaluation items. As a result of the analysis, it was found that the weight of user satisfaction was higher than that of management evaluation. In addition, the weights for each detailed indicator of management evaluation were in descending order of facility management, company management, and financial soundness, and it was analyzed that the management of facilities directly used for services was important. User satisfaction is in descending order of safety, punctuality, service satisfaction convenience, and transparency. These results show that securing safety is a top priority, and that the inherent quality of services such as safety and punctuality is more urgent than those of the convenience and transparency of the process in terms of providing preliminary services.

• Journal of Advanced Technology Convergence
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• v.1 no.1
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• pp.1-6
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• 2022

Since 2015, the government has been making efforts to distribute Korean smart farms. However, the supply is limited to large-scale facility vegetable farms due to the limitations of technology and current cultivation research data. In addition, the efficiency and reliability compared to the introduction cost are low due to the simple application of IT technology that does not consider the crop growth and cultivation environment. Therefore, in this paper, data analysis services was performed based on public and external data. To this end, a data-based target smart farm system was designed that is suitable for the situation of farms growing in facilities. To this end, a farm risk information notification service was developed. In addition, light environment maps were provided for proper fertilization. Finally, a disease prediction model for each cultivation crop was designed using temperature and humidity information of facility farms. Through this, it was possible to implement a smart farm data service by linking and utilizing existing smart farm sensor data. In addition, economic efficiency and data reliability can be secured for data utilization.

• Health Policy and Management
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• v.32 no.3
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• pp.317-322
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• 2022

Background: Limited access to medical services causes problems in patients' health and life. Also, hospital closures cause concentration towards general hospitals, which leads to worsening National Health Insurance finance. Therefore, hospital closure is an important topic to be analyzed. Methods: This paper analyzed the factors that affect hospital closures using survival analysis with the data of 970 hospitals opened between 2010 and 2019 in Korea. The number of medical personnel, hospital rooms, sickbeds, and medical departments were used as explanatory variables. Results: The number of medical personnel and hospital rooms increased the survival probability while the number of sickbeds and medical departments decrease the survival probability. Conclusion: The results suggest that hospitals have economies of scale and diseconomies of scope in management.

• Korea Journal of Hospital Management
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• v.8 no.4
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• pp.59-75
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• 2003

This study was conducted to investigate the degree of utilization of outsourcing in large hospitals in Korea. We also investigated the outcome and the level of satisfaction for adopting outsourcing in these hospitals. Types of work areas that were currently operated by outsourcing and were planned to adopt outsourcing in the future were identified. A total of 83 hospitals were eligible for this study, which had more than 500 beds, and were identified from the 2003 National Hospital List published by the Korean Hospital Association. A self-administered Questionnaire survey was conducted between April 25th and May 20th in 2003 with a personnel being charged of arrangement of outsourcing in each hospital. Among the 58 hospitals responding the survey(response rate=69.9%), 49 hospitals(84.5%) utilized outsourcing in at least one work field in their organizations. The largest proportion of the hospitals(85.7%) using outsourcing responded that the biggest outcome after introducing outsourcing were cost reduction(49.0%), followed by improved efficiency in operating the organization or human resources(34.7%) and the improved quality of the work(6.1%). The degree of satisfaction for outsourcing among the hospital managers(3.43) was significantly higher than that among the employees(3.l4) on a S-point Likert-type scale(p<0.05). Among the 7 work areas, the hospitals used outsourcing most frequently in facility management(housekeeping, building maintenance, hospital security and parking management), followed by non-medical profit business(funeral, convenient store, and cafeteria), logistics(provision of patient meal, in-house delivery, and purchasing), and information and computing system(hospital information system, maintenance of personal computers and printers). The work areas that the hospitals planned to adopt or expand the outsourcing in the future most frequently were facility management, non-medical profit business, logistics, and information and computing systems. In conclusion, outsourcing was highly diffused in large Korean hospitals, particularly in the work field of facility management and non-medical profit business. The satisfaction for outsourcing was not high yet in Korean hospitals.

• Journal of Internet Computing and Services
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• v.19 no.1
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• pp.87-95
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• 2018

Due to global warming and increased energy costs around the world, interests of energy saving and efficiency have been increased. In particular, forging factories need methods to save energy and increase productivity because of needing amounts of energy uses. To solve the problem, we propose a system, which includes collection, monitoring, and analysis process, to monitor energy uses each facility in realtime based on the IoT devices. This system insists of worksheets management, facility/energy management, realtime monitoring, history search, data analysis through connecting with existed ERP/MES Systems in manufacturing factories. The energy monitoring process is to present used energy collected from IoT devices connected with installed gasmeter and wattmeter each facility. This system provide the change of energy uses, usage fee, energy conversion, and green gas information in realtime on Web and mobile devices. This system will be enhanced with energy saving technology by analyzing constructed big data of energy uses. We can also propose a method to increase productivity by integrating this system with functions of digitalized worksheets and optimized models for production process.

• Journal of The Korea Institute of Healthcare Architecture
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• v.12 no.2
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• pp.41-50
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• 2006

Introduction of new longterm care policy for elderly in Korea would change many aspects of elderly care service facilities. Especially elderly home care services like adult daycare centers will expand drastically after beginning of longterm care insurance. The purpose of this study is to estimate demand of adult daycare centers by comparing with the U.S and Japanese cases. Korean government is expecting that adult daycare centers will expand ten times within 4 years. This estimate is exceeding the facility demand estimate of the U.S. and Japan. The results of population study and expecting growth rate of adult daycare centers in Seoul indicate that more than 300 centers, 4 times of the number of existing centers, are in need based on Seoul elderly population in 2004. To supply these numbers of facilities in short period, more in depth study should be followed. Existing adult daycare facilities' in Seoul were analyzed by their building and management types. Interior spaces of adult daycare centers in Korea are similar to the U.S. and Japan in space arrangements but much smaller in size. In depth study of space programming as well as overall demand survey of adult daycare centers is urgently in need for more realistic expansion of adult daycare centers.