• Journal of Information Technology Applications and Management
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• v.14 no.4
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• pp.221-233
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• 2007

Which factors should influence consumer consideration to subscribe to Voice over Internet Protocol (VoIP)? Policy issues, managerial concerns, and demographic variables are possible factors. This paper discusses policy and managerial issues regarding VoIP adoption. A model that explains VoIP adoption is proposed and tested. This study analyzes a survey of 750 prospective VoIP users in Korea. The testing is accompanied by logistic regression and discriminant analysis. The results show that trust in VoIP, relative comparison of Quality to fixed service, numbering plan, satisfactions of call Quality and customer services on both fixed and mobile services have impacts on the adoption of VoIP. Implications for VoIP providers and policy makers are presented.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.10
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• pp.1128-1135
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• 2010

The relay based cellular system has been introduced to provide the service to satisfy the user requirement. The main reasons of using relay station are to expand a service coverage and to increase a system throughput with satisfying the service requirement level. This paper proposes a new resource allocation algorithm which supports the users' throughput fairness and service coverage in the Fixed Relay Based Cellular system with OFDMA. The performance of proposed algorithm is compared with the performances of proportional fairness(PF) algorithm. The simulation result shows that the proposed algorithm increases the number of active users in the service coverage while paying small amount of throughput loss.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1350-1354
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• 2014

Although there were many activities to provide FMC (Fixed Mobile Convergence) service by several foreign countries such as United States, FMC service could not make a good success for a number of reasons for example, customers indifference and lack of needs. On the other hand, recently FMC is showing its good progress at B2B market in foreign government such as in Germany and US satisfying e-government and BYOD (Bring Your Own Device) needs. This paper studies FMC service of foreign countries and as a result makes a analysis presenting issues for Korean e-government service. Also, we make several suggestions to energize FMC service success.

• IE interfaces
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• v.17 no.4
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• pp.459-465
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• 2004

The purpose of this paper is to examine whether there are relationships of substitutability or complementarity between the call demand of fixed telecommunication and mobile telecommunication services. In order to clarify the relationships, we suggest a model of call demand of fixed telecommunication service which incorporates the variables representing the diffusion of mobile telecommunications subscription and estimate it with relevant time series data. Finally it is shown that there is complementary relationship between the call demand of fixed telecommunication and mobile paging services, and it is also found that there is substitutable relationship between the long distance call demand of fixed telecommunication and mobile phone services.

• Journal of Information Technology Applications and Management
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• v.9 no.4
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• pp.151-164
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• 2002

This paper predicts how mobile Internet portal services will go ahead and what contents will be needed at the portal site. Mobile Internet interface needs to be concise and compressed because of the size of terminals Thus mobile internal service wants integrated portal service We study the service strategy for mobile internet portal Service according to the product life cycle Many Korean people who have used 'wired and fixed' Internet services and mobile phones want the mobile Internet portal to provide many attractive functions and high quality of service Thus we consider the current Korean mobile Internet service as the maturity phase of its life cycle The maturity phase needs the strategy of diversifying and focusing on, thus we recommend the hub portal model for Korean mobile Internet service, In this paper, we survey contents of mobile Internet portal service as a case study. With the result of the analysis, we present the promising contents as follows: video conference service, financial service, stock trading service, traffic information service, location map service, emergency rescue service, and so on.

• Journal of Information Technology Services
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• v.6 no.3
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• pp.87-110
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• 2007

Recently, researches on IT Service Management (ITSM) for improving information system operation service and information system outsourcing cost estimation model are proliferating. This study suggests a new cost model of IT operation service and optimizing method based upon the characteristics of operation service as a long-term and continuous business service for both user's and service provider's point of view. This study explains the cost optimization model of IT operation service by improving service request management process, such as adequate reception and control, proper valuation, process management using project management methodology, effective organization and time management of service personnel. Especially in this study, service ability improvement effect and fixed operation cost reduction effect are defined to prove the proposed new cost model.

• Journal of Advanced Navigation Technology
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• v.15 no.1
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• pp.11-17
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• 2011

In this paper, we consider the frequency sharing feasibility of Fixed Satellite Service (FSS) with Microwave Landing System (MLS) allocated in the C-band. On the basis of characteristics of MLS and FSS suggested by ITU and safety standards of MLS by ICAO, three interference scenarios are built and numerical simulations are carried out for investigating the frequency sharing between the two systems. From the simulation results, we calculate the separation distance between MLS and FSS ground antennas, required for frequency sharing by employing standard protection limits regulating the interference to noise ratio (I/N) of the receiver.

• Journal of Internet Computing and Services
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• v.9 no.3
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• pp.119-128
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• 2008

To use commercial software, most software users purchase the software. Some software users, who do not use the software frequently, regard purchasing the software as undue expense. Software rental service can be an effective substitute. To support the software rental service, charging scheme is necessary. Two categories of charging scheme can be considered. One is charging a fixed amount of fee for a fixed period of time and the other is charging a fee based on the actual usage time. In this paper, the software pay-per-use approach based on the amount of time that the software user has used is proposed. The proposed approach gives the capability to calculate the usage time.

• Journal of Preventive Medicine and Public Health
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• v.52 no.4
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• pp.234-241
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• 2019

Objectives: To identify simultaneous behavioral changes in alcohol consumption, smoking, and weight using a fixed-effect model and to characterize their associations with disease status. Methods: This study included 7 000 529 individuals who participated in the national biennial health-screening program every 2 years from 2009 to 2016 and were aged 40 or more. We reconstructed the data into an individual-level panel dataset with 4 waves. We used a fixed-effect model for smoking, heavy alcohol drinking, and overweight. The independent variables were sex, age, lifestyle factors, insurance contribution, employment status, and disease status. Results: Becoming a high-risk drinker and losing weight were associated with initiation or resumption of smoking. Initiation or resumption of smoking and weight gain were associated with non-high-risk drinkers becoming high-risk drinkers. Smoking cessation and becoming a high-risk drinker were associated with normal-weight participants becoming overweight. Participants with newly acquired diabetes mellitus, ischemic heart disease, stroke, and cancer tended to stop smoking, discontinue high-risk drinking, and return to a normal weight. Conclusions: These results obtained using a large-scale population-based database documented interactions among lifestyle factors over time.

• The Korean Journal of Health Service Management
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• v.11 no.3
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• pp.51-64
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• 2017

Objectives : This study examined the effect of private health insurance on medical care utilization by subscription type. Methods : The data used were the six waves of the Korea Health Panel (2009-2014), and 16,187 persons were the subjects of the analysis. We performed a panel regression with a fixed effects model. Results : Indemnity private health insurance was positively related to the number of physician visits, number of admissions, and total length of stays. However, fixed-benefit private health insurance was not related to medical care utilization. Conclusions : The result of this study, which shows the difference by subscription type in the effect of private health insurance on medical care utilization, suggests that continuous monitoring of indemnity private health insurance is needed in the future.