• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.4
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• pp.69-76
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• 2011

In this paper, we present the analytic model to quantify the system capacity with delay Quality of Service (QoS) constraints, and analyze the effect of user-multiplexing on the delay QoS performance in multiuser low-power wireless communication systems. For this purpose, we define the degree of multiplexing as the number of scheduled users to be served in a frame, and investigate the effect of degree of multiplexing (DoM) on the trade-off of throughput and delay QoS constraints. Through this analysis, we characterize the optimal DoM maximizing the energy efficiency in low-power communication environments. Finally, through the simulation results, we verify that our approach with its optimal DoM yields substantial capacity gain.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.3
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• pp.317-324
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• 2016

WiMedia provides the data rate of up to 1Gbps, but the transmission range is restricted to approximately 10 meters. When constructing a multi-hop WiMedia network to extend its coverage, conventional hop-based routing may not guarantee satisfactorily the required QoS. We propose two QoS routing techniques for the WiMedia-based wireless mesh network. The proopsed QoS routing reflects the characteristics of TDMA-based WiMedia MAC and develops QoS extensions separately for on-demand routing and table-driven routing. Through simulations, we identify that the QoS routing shows better performance than the hop-based routing. It also turns out that the QoS on-demand routing and the QoS table-driven routing show conflicting performance results depending on the transmission power.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.11
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• pp.1135-1140
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• 2016

The main challenge in designing wearable WBANs is to guarantee the balance of QoS demands in the network with the low power constraints of limited battery powered nodes. Low power devices implanted in or attached to the body should be designed to meet minimum energy requirements due to their limited battery life and be small in size to be easily wearable. In this paper, we propose a method for optimizing channel allocation method that is compatible with the IEEE 802.15.6 standard, enables the maximum amount of power charge at idle, guarantees the QoS of a WBAN, and provides the reliable date transmission between nodes and hubs in the network. Our extensive simulations will show that the method we propose not only maximizes the QoS in packet transmission but also improves the level of energy efficiency.

• Korea Journal of Hospital Management
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• v.19 no.2
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• pp.73-88
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• 2014

Objective: This research investigates how to increase the quality of medical service and supply high quality of medical service to patients. By using Kano Model theory we examines what medical service attributes the hospital would be conducted preferentially for patient's satisfaction and provides informations of management strategies for hospitals. Method: To study patients' perception of medical service quality, first we performed pilot test to derive 30 medical service attributes. With 30 medical service attributes, we conducted survey of 300 subjects who have experienced medical services in 6 months. To examine patients' conception of medical services, a modified Kano's questionnaire using 5 scale is applied. Finally we calculated SI(Satisfaction index) and DI(Dissatisfaction index) and PCSI(Potential Customer Satisfaction Improvement) index with Kano's Model analysis results. Key Findings: We found that the quality of medical service categorized in 15 one-dimensional elements, 9 must-be elements and 6 indifferent elements. Moreover the attribute of gives prompt services and have patient's best interest at heart scored the highest SI, whereas the attributes of accurate and precise medical service, exact records, enough explanation and polite attitudes are the highest score of DI. And also good explanation of the bill scored the highest PCSI. In this study findings indicate that while medical service providers try to increase patients' satisfaction by improving hospital's environments, patients' perception of trust and good interpersonal relationships with medical service providers have strong and positive impact on patients' satisfaction.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.8
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• pp.725-729
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• 2016

The regular inspection of vehicles that are in service in domestic country, i.e., vehicle safety and emission gas inspection have been forced by the korea transportation safety authority and a private servicing enterprise according to the vehicle administration law (1995). In the safety inspection process, which is developed by a compatible inspection system and method, every effort is made to increase the reliability of vehicle safety and the service quality, and to protecting national health. In this study, the reliability of the braking force inspection method in the current regular vehicle inspection was studied statistically by comparing the dynamic braking force inspection method with the static braking force inspection method. Further, the problems and characteristics of the current braking force inspection methods were analyzed. Form the results for the dynamic braking force inspection equipment (H), a mean correction factor (y=18.61+2.18x) was obtained for the axle braking force ratio according to vehicle entering velocity.

• Journal of Korea Multimedia Society
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• v.9 no.3
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• pp.323-332
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• 2006

Fair packet scheduling algorithms supporting quality-of-services of real-time multimedia applications can be classified into the following two schemes in terms of the reference time used in calculating the timestamp of arriving packet; the Finish-Time (FT) and Start-Time (ST) schemes. The FT scheme, used in most schedulers, that has the property of an inversely rate-proportional latency is suitable to support various delay bounds because it can adjust the latency of a flow with raising the flow's reserved rate. However, the scheme may incur some bandwidth loss due to excess rate reservation. Meanwhile, although the ST scheme does not suffer from the bandwidth loss, it is hard to support multiple delay bounds because of its latency property relying on the number of flows. This paper is devoted to propose a ST scheme based scheduler to effectively support multiple delay bounds and analyze its performance comparing to the FT scheme based scheduler. The comparison results show that the proposed scheduler gives better utilization by up to 50%.

• International Commerce and Information Review
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• v.10 no.4
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• pp.125-151
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• 2008

Website service quality is widely accepted as one of the key determinants of online business success. Several studies identified key factors that determine the website service quality factors appropriate for online business environments. A convention and visitors bureau (CVB) website is a service portal that delivers information online about a destination so users can develop an overall image of the location. CVBs struggle to deliver positive destination images because the competition among destinations to host conventions is intense. In spite of the important role of CVBs and the beneficial spillover effect of CVBs, there are few studies available reporting on the unique service qualities of a CVB website. The primary purpose of this study was to examine the determining factors that are appropriate for CVB websites from the meeting planners' perspective. The research questions arc: What are the determining factors of service quality of a CVB website? Do the determining factors of CVB website service quality positively influence meeting planners' satisfaction? The new conceptual framework was developed from a variety of destination marketing and Internet marketing concepts: e-servicescape management, web community network, Internet service encounter management, and online system quality. Empirical results indicate that three of the four factors, that is, e-servicescape, web community network, and online system quality are important determinants in evaluating CVB website service quality. The findings also show that three determinants have significant and positive influence on meeting planners' satisfaction. The findings from this study will provide meaningful advice for CVB website quality management. To enhance the CVB website service quality and satisfaction level of meeting planners, these three determinants' should be considered of the utmost strategic importance and priority.

• Knowledge Management Research
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• v.21 no.2
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• pp.137-157
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• 2020

The medical tourism industry, a convergence of medical services and tourism, has been getting more and more popularity as a new value-added industry in the 21st century. Accordingly, the number of professional workers within this industry has been increasing, and the role of educational institutions to cultivate well-equipped human resources has also become critical. However, compared to practically activated medical tourism-related education programs, studies investigating the effectiveness of these education programs are relatively rare. Therefore, this study attempts to examine the effect of five dimensions of medical tourism education service quality (i.e., tangibles, reliability, responsiveness, assurance, and empathy) on learners' education satisfaction and transfer of education training. In addition, the moderating roles of national relations as well as organizational characteristics (i.e., transfer climate and support of supervisors and colleagues) in the relationship between education satisfaction and transfer of education training are further verified. The results of the structural equation model (SEM) using 151 samples from respondents with experience in completing medical tourism education programs reveal that tangibles, reliability, and assurance are found to have a significant impact on education satisfaction, which in turn leads to a high level of transfer of education training. Moreover, it is found that national relations and support of supervisors and colleagues play a moderating role. This study would provide guidelines for improving the efficiency of educational institutions, creating outcomes for learners' affiliated firms (e.g., hospitals), and promoting medical tourism at the national level from the perspective of medical tourism education.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1853-1858
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• 2015

The existence communications of vessel focused on voice, FAX, ISDN, etc. using satellite on the existent most communications on the ships, and recently, the ships need high quality smart communication service environments. In the results of experiments using the existent system, it could access on board, but in the closed room of vessel, was impossible to access e-mail and smart apps except voice communication. In the present paper, we implemented a novel communication system that can access voice, text, e-mail, file, vessel monitoring apps, etc. It consists of a convergent communication terminal combined with satellite and communication for Smartphone, and smart communication environment on the closed room. As the results, we can access a variety of smart communication in anywhere on board.

• Journal of Broadcast Engineering
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• v.16 no.3
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• pp.490-500
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• 2011

The channels of domestic FM broadcast are needed to provide various kinds of new broadcasting services. However, available channels are limited and saturated. The channel interval of FM broadcast is changed from 200 kHz to 100 kHz to maximize utilization efficiency of scarce broadcast spectrum at all over the world. Also, there are many researches such as IBOC(In Band On Channel) and DRM+(Digital Radio Mondial+) that is to allocate the digital signal beside analog bandwidth. But output power is decrease to avoid interference between adjacent radio stations. In this paper, we analyzes the problems of the protection ratio which is decided in 1986 and we propose method to improve about 7~10dB significantly the protection ratio according to the recent DSP(Digital Signal Processing) techniques without loss of both transmission power and broadcast quality. In addition, we examined the possibility of securing two times available channels by reducing minimum frequency interval from 800 kHz to 400 kHz or 600 kHz in the equal site.