• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.2
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• pp.110-115
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• 2006

In pure P2P environment, it is possible to provide service by using a little real-time information without using accumulated information. But in case of using only a little information that was locally collected, quality of recommendation service can be fallen-off. Therefore, it is necessary to study a method to improve qualify of recommendation service by using users' context information. But because a great volume of users' context information can be recognized in a moment, there can be a scalability problem and there are limitations in supporting differentiated services according to fields and items. In this paper, we solved the scalability problem by clustering context information per each service field and classifying it per each user, using SOM. In addition, we could recommend proper services for users by quantifying the context information of the users belonging to the similar classification to the service requester among classified data and then using collaborative filtering.

• The Journal of Information Systems
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• v.14 no.1
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• pp.125-147
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• 2005

This research focused on the comparison of corporate business mokels to explain different financial performances on the eBusiness domain. Especially, because customers have the more buying [ower tha other business areas, customer value and the service quality were prepared for independent variables and operational margin which can be obtained by publicize report was used for a dependent variable in stead of the other variables dependent on human perception as well. As a result, this research found that the customer value measured by service quality concept impact on the financial performance of eBusiness corporation positively. To find out more delicate results, structural equation was used for statistical method using 324 survey samples on 10 corporations. Though data using for statistical analysis were divided into individual and corporate level and have the time gap between research time and financial performance publicized period, the value of this research is that the customer value and service quality concepts with very objective financial information were input for constructing a research model.

• Journal of Communications and Networks
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• v.14 no.6
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• pp.597-605
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• 2012

With the smart grid coming near, wide-area supervisory control and data acquisition (SCADA) becomes more and more important. However, traditional SCADA systems are not suitable for the openness and distribution requirements of smart grid. Distributed SCADA services should be openly composable and secure. Event-driven methodology makes service collaborations more real-time and flexible because of the space, time and control decoupling of event producer and consumer, which gives us an appropriate foundation. Our SCADA services are constructed and integrated based on distributed events in this paper. Unfortunately, an event-driven SCADA service does not know who consumes its events, and consumers do not know who produces the events either. In this environment, a SCADA service cannot directly control access because of anonymous and multicast interactions. In this paper, a distributed security framework is proposed to protect not only service operations but also data contents in smart grid environments. Finally, a security implementation scheme is given for SCADA services.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.1
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• pp.33-40
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• 2007

A multi-server queueing system with finite buffer is considered. The input flow is the BMAP (Batch Markovian Arrival Process). The service time has the PH (Phase) type distribution. Customers from the BMAP enter the system according to the discipline of partial admission. Besides ordinary (positive) customers, the Markovian flow (MAP) of negative customers arrives to the system. A negative customer can delete an ordinary customer in service if the state of its PH-service process belongs to some given set. In opposite case the ordinary customer is considered to be protected of the effect of negative customers. The stationary distribution and the main performance measures of the considered queueing system are calculated.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.103-111
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• 2017

Purpose: Accelerated degradation tests can speed time to market and reduce the test time and costs associated with long term reliability tests to verify the required service life of a product or material. This paper proposes a service life prediction method for components or materials using an accelerated degradation tests based on the relationships between temperature and the rate of failure-causing chemical reaction. Methods: The relationship between performance degradation and the rate of a failure-causing chemical reaction is assumed and least square estimation is used to estimate model parameters from the degradation model. Results: Methods of obtaining acceleration factors and predicting service life using the degradation model are presented and a numerical example is provided. Conclusion: Service life prediction of a component or material is possible at an early stage of the degradation test by using the proposed method.

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.230-237
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• 2022

The Community Social Service Investment project started as a state subsidy project in 2007 and has grown very rapidly in quantitative terms in a short period of time. It is a bottom-up project that discovers the welfare needs of people and plans and provides services suitable for them. The purpose of this study is to analyze using big data to determine the social response to local community service investment projects. For this, data was collected and analyzed by crawling with a specific keyword of community service investment project on Google and Naver sites. As for the analysis contents, monthly search volume, related keywords, monthly search volume, search rate by age, and gender search rate were conducted. As a result, 10 items were found as related keywords in Google, and 3 items were found in Naver. The overall results of Google and Naver sites were slightly different, but they increased and decreased at almost the same time. Therefore, it can be seen that the community service investment project continues to attract users' interest.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.374-380
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• 2017

In this study, we analyzed the situation of the 119 emergency medical service zone of H town, countryside of Y city from January 1st, 2015 to December 31st, 2016 and then, on the basis of this analysis, we investigated the present condition of the patient-transportation service of the 119 emergency medical service to provide the basic data in order for patients to use the emergency medical service more efficiently. We analyzed the data with SPSS 21.0 using frequency analysis and, after positioning the virtual 119 emergency medical service, we analyzed the data of the transportation time and transportation distance by using GIS. The results of this study show that the use of the 119 emergency medical service for people over 65 years old represents approximately 57% of the total number of patients transported, The average distance and time of the real moving reaction are 6.41 km and 11.86 min, respectively. The distance and time from the pick-up location to the hospital are 18.24 km and 21.52 min, respectively. Given the present position of the 119 emergency medical service, the results of this analysis using GPS show that the (average) distance and time from the 119 emergency medical service to Jang * Ri town are 9.12 km and 12 min, and the (average) total distance and time to arrive at the hospital after the emergency medical service picks up the patient are 36.83 km and 62 min, respectively. In the case of the virtual emergency medical service, the total distance and time required to arrive at the hospital after the emergency medical service picks up the patient are 27.71km and 50min, respectively. The results of this study showed that the present position of the 119 emergency service does not provide the optimum distance and time from the patient's location to the hospital. Therefore, we consider that the repositioning of the 119 emergency medical center is necessary, in order to reduce the time required for the emergency medical service to move to the patient's location and then bring the patient to the hospital.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8820-8829
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• 2015

While medical services are recognized to be crucial in a process of disease treatment, the research has been done with the service space and waiting time in a medical institution. This paper's objective is to evaluate the waiting areas of lobby, outpatient clinic, operating room in a general hospital and to draw factors of architecture design for further improvement, identifying strengths and weaknesses to be analyzed in terms of medical service. Research method is to define concepts of waiting time through literature review and advanced researches, analyze characteristics of architectural plan through drawing analysis and site survey. This research will contribute to the improvements of the planning methods which will reduce the waiting time and increase the quality of medical service.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.3
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• pp.226-235
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• 2006

Telematics is expected to be one of the fastest growing businesses in information technology area. It may create a new emerging market in industry related to automotive, telecommunications, and information services. Especially vehicle navigation service is considered as a killer application among telematics service applications. The current vehicle navigation service typically recommends a single path that is based on the traveling time or distance from the origin to the destination. The system provides two options for users to choose either via highway or via any road. Since the traffics and road conditions of big cities are very complicated and dynamic, the demand of multi-path guidance system is increasing in telematics market. The multi-path guidance system should allow drivers to choose a path based on their individual preferences such as traveling time, distance, or route familiarity. Using the Lawler's algorithm, it is possible to find multiple paths; however, due to the lengthy computational time, it is not suitable for the real-time services. This study suggests a computationally feasible and efficient heuristic multiple paths finding algorithm that is reliable for the real-time vehicle navigation services.

• Steel and Composite Structures
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• v.36 no.5
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• pp.521-531
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• 2020

The behavior variation of concrete dam is investigated, based on a new method for analyzing the data model of concrete dam in service process for the limitation of wavelet transform for solving concrete dam service process model. The study takes into account the time and position of behavior change during the process of concrete dam service. There is no dependence on the effect quantity for overcoming the shortcomings of the traditional identification method. The panel data model is firstly proposed for analyzing the behavior change of composite concrete dam. The change-point theory is used to identify whether the behavior of concrete dams changes during service. The phase space reconstruction technique is used to reconstruct the phase plane of the trend effect component. The time dimension method is used to solve the construction of multi-transformation model of composite panel data. An existing 76.3-m-high dam is used to investigate some key issues on the behavior change. Emphasis is placed on conversion time and location for three time periods consistent with the practical analysis report for evaluating the validity of the analysis method of the behavior variation of concrete dams presented in this paper.