• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.295-302
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• 2011

In this paper we consider technological requirements to broadcast digital television signals using single frequency networks(SFN) in the Advanced Television Systems Committee(ATSC) transmission systems and propose Interference Cancellation Digital On Channel Regenerative Repeater(IC-DOCR) thar overcomes the limitation of EDOCR(Equalization Digital On Channel Repeater) proposed by ETRI. The proposed IC-DOCR maintains the benefits of EDOCR that have good output signal quality removing multi-path, additive white Gaussian noise(AWGN). In additional, since the Interference Cancellation algorithm using the 8-VSB symbol demodulation of received signal removes the Interference of feedback signal, IC-DOCR improve the weakness of EDOCR that have low isolation between receive and transmit antenna so that can overcome the limitation of output signal power. we did analysis and verification of the proposed system performance using computational simulation.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.51-59
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• 2015

In this study, we derived key factors required for the activation of the domestic e-book market and evaluated its importance. Specifically, we derived key evaluation items of C-P-N-D ecosystem perspective through literature review. In addition, we analyzed the implications by evaluating the importance depending on AHP after derived items were modified and classified together with the publisher working group. As the results of analysis, experts considered price(0.785), quality(0.149) and service(0.066) as the important items among three items derived as the primary upper class. A total of 23 factors were derived as the secondary lower class. The importance depending on C-P-N-D areas is as follows: contents(0.43), platform(0.35), device(0.11) and network(0.05). Among the entire sub-factors, three items such as 'distribution of profits with platform', 'profitability of product costs of contents' and 'appropriate rental price of contents and streaming service' showed significantly higher importance than that of other 20 items.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.339-348
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• 2014

This study searches an improvement scheme of auditing on international financial environment since enforcing IFRS in order to secure transparency and reliability in corporate accounting and credibility in external audit from 2011 K-IFRS. As improvement schemes for the issue of the audit on K-GAAP are: First, the guarantee of the auditor's qualities of duties and talents about the lack of accountability and awareness and independence of auditor are needed. Secondly, the free acceptance or certified public accountant is adopted. Third, the non-Executive Director shall be granted. Fourth, the external auditor CPA and Auditor's remuneration should be increased. Fifth, the auditor's shares shall be limited. Sixth, the external audit to supervise and the ratio of supervision should increase. Finally, the foreign corporation for the time being limited to increase our competitiveness.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.183-191
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• 2014

SNS uses the Internet as its base. It is created in order to achieve communication between the users. Up until now, most previous research were focused on the users of SNS. But, there are still a great deal of people who do not use or discontinuously use SNS. This is because users have natural resistance against SNS when using the service. In this study, time shortage perception, awareness of SNS, self-efficacy, suitability, information quality of SNS, subjective norm and privacy concern are considered as influence factors by previous research. An empirical study for Chinese students and internet users was conducted to identify how these factors influence perceived risk and perceived usefulness, and how this influence to user's resistance. This study can explain the reason why users don't use SNS and resist SNS use.

• Journal of Internet Computing and Services
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• v.14 no.4
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• pp.13-24
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• 2013

IEEE 802.15.4 network and WiFi network are installed to overlap each other and configured to use adjacent frequency bands in which case the communication service required by applications can not be guaranteed because of randomly increased frame transmission delay and frequent frame transmission failures at nodes in IEEE 802.15.4 network. In this paper, transmission delay model at IEEE 802.15.4 nodes and an experimental system to evaluate the interference from WiFi traffic are described, then elements for the evaluation of interference are measured with the analysis of their characteristics. A sequential method of using medium access layer and physical layer elements of IEEE 802.15.4 protocols is proposed to decide interference from WiFi network. With the proposed method, if an evaluation function having frame transmission failures and transmission delay as variables returns a value greater than a threshold, intensive measurements of wireless channel power are carried out subsequently and the final decision of interference is made by the calculated average channel power. Experimental results of the method show that the decision time is reduced with increased frequency of decision in comparison to an other similar method.

• Korean journal of food and cookery science
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• v.32 no.1
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• pp.96-106
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• 2016

The purpose of this study was to evaluate the service quality attributes of Korean restaurants by North American and Chinese residents in Korea based on the Kano model. This survey was performed from September to December 2010. The subjects consisted of 135 North Americans and 165 Chinese in Seoul. The service quality attributes of Korean restaurants were composed of twenty three items in the categories of 'food quality', 'employee's service quality', 'sanitation quality', 'facility quality', and 'convenience quality'. For North Americans, there were five 'attractive quality' items, eleven 'one-dimensional quality' items and six 'indifferent quality' items, and one item had the same frequency on both 'attractive quality' and 'one-dimensional quality'. For the Chinese, there were twelve 'attractive quality' items, and ten 'one-dimensional quality' items, and one item had the same frequency on 'attractive quality' and 'one-dimensional quality'. According to the customer satisfaction coefficient developed by Timko, 'taste of the 'food (0.80)' for North Americans and 'freshness of the ingredients (0.94)' for Chinese were highest scores in the 'Better coefficient'. On the other hand, within the 'Worse coefficient', 'sanitation of the food' had the lowest score for both North Americans (-0.89) and Chinese (-0.90).

• Physical Therapy Korea
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• v.17 no.2
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• pp.75-83
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• 2010

This study purposed to analyze difference in the perception of service quality between physical therapy patients and physical therapists and to provide basic materials for maintaining high service quality that meets patients' expectation in each service area. For this study, we conducted a questionnaire survey with physical therapy patients and physical therapists in Jeju from the 6 to 30 of January, 2010. In the survey, we received 133 questionnaires from patients and 125 from physical therapists, and used them in analysis. The instrument used in this study to measure service quality was prepared by the researcher through adapting and supplementing the SERVQUAL model developed by Parasuraman et al (1991). For our physical therapy environment, and it consisted of a total of 23 questions in five areas, namely, tangibility, reliability, responsiveness, assurance, and empathy. Patients' perception of service quality was high in order of reliability, assurance, empathy, responsiveness, and tangibility. In four areas with exception of reliability, quality perceived by patients was lower than that perceived by physical therapists, and particularly in responsiveness(t=2.82, p=.00) and empathy(t=2.02, p=.04), the difference between patients and physical therapists was statistically significant. In order to reduce the difference in the perception of service quality between patients and physical therapists, it is considered necessary to enhance physical therapists' perception of service quality and to prepare measures for improving service equality so that services would be provided through respectful communication with maintaining the dignity of patients, rather than focusing on disease.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.151-158
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• 2010

In line with the requirement of appropriate protocol support for such mission-critical wireless sensor network (WSN) applications as patient monitoring, we investigate the framework for designing medium access control (MAC) schemes. The data traffic in medical systems comes with inherent traffic heterogeneity as well as strict requirement of reliability according to the varied extents of devise-wise criticality in separate cases. This implies that the quality-of-Service (QoS) issues are very distinctly delicate requiring specialized consideration. Besides, there are features in such systems that can be exploited during the design of a MAC scheme. In a monitoring or routine surveillance application, there are degrees of regularity or predictability in traffic as coordinated from a node of central control. The coordinator thus takes on the role of marshaling the resources in a neighborhood of nodes deployed mostly for upstream traffic; in a collision-free scheme, it schedules the time slots for each superframe based on the QoS specifications. In this preliminary study, we identify the key artifacts of such a MAC scheme. We also present basic performance issues like the impact of superframe length on delay incurred, energy efficiency achieved in the network operation as obtained in a typical simulation setup based on this framework.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.219-236
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• 2014

In this paper, we propose a novel Proxy Mobile IPv6 network bandwidth-efficient handoff scheme. MN are classified into slow and fast one. At first MN should be registered in the microcell for bandwidth efficient handoff scheme. microcell is overlapped to handle the overflow session request which is nested. Overflow session request in macrocell requests to go back from the boundary of the microcell to new microcell. If idle session traffic is in a cell, it is requested by the target microcell. Analysis model was developed, an existing session of the session blocking probability and forcing termination probability of the session request have improved considerably. If the total traffic load of the system is not very large, the proposed scheme has the best bandwidth efficiency and provides better quality of service (QoS) to MN without costs of a lot of processing on the system.

• Journal of the Korean Data and Information Science Society
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• v.24 no.3
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• pp.411-425
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• 2013

The importance and necessity of the credit loan are increasing over time. Also, it is a natural consequence that the increase of the risk for borrower increases the risk of non-performing loan. Thus, we need to predict accurately in order to prevent the loss of a credit loan company. Our final goal is to build reliable and accurate prediction model, so we proceed the following steps: At first, we can get an appropriate sample by using several resampling methods. Second, we can consider variety models and tools to fit our resampling data. Finally, in order to find the best model for our real data, various models were compared and assessed.