• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.618-630
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• 2011

Mobile RFID system, that consists of the existing RFID reader mounted on the mobile devices such as smartphones, is able to provide the users a variety of services and convenience. Although the users can get the information about a certain product anytime anywhere, there is high probability that their privacy may be violated because their belongings with RFID tags can be scanned by other mobile readers at any time. Several RFID authentication schemes have been proposed to deal with these privacy issues. However, since the existing solutions require heavy computation on the tag side, most of them is not applicable to the general low-cost passive tags which do not have any processing unit. In this paper, we propose the efficient authentication scheme for mobile RFID system applicable to the passive tags as well as the active ones by the best use of computing capability of mobile devices. The proposed scheme satisfies the import security issues such as tag protection, untraceability, anti-traffic analysis. We also implement the proposed scheme on top of real smartphone for feasibility and show the experimental results from it.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.121-126
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• 2018

IEEE 802.1 TSN TG is developing standards for end-to-end delay bounds and zero packet loss based on Ethernet technology. We focus on packet forwarding techniques. TSN packet forwarding techniques can be classified into Synchronous and Asynchronous framework. Synchronous approach allocates fixed time period for a class, yet is complex for large networks. Asynchronous approach provides delay guarantee by regulator-scheduler pair, yet is unnecessarily complex, too. We propose network components for TSN Asynchronous architecture, which remove the complexity of maintaining flow state for regulation decisions. Despite such a simplicity, the proposed architecture satisfies the TSN's delay requirements provided the limited high priority traffic's maximum packet length.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.478-485
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• 2019

This is an exploratory study to examine factors affecting South Korean companies' intentions to use big data technology and services based on whether the companies use public data or not. This study, using R, conducted chi-squared tests and logistic regression analysis. As a result of the logistic regression analysis, cost reduction had a positive effect on the big data-use intentions in companies that use public data, whereas with companies that do not use public data, customer satisfaction had a positive impact, and support for decision-making had a negative impact on the intention to use big data. Recently, the South Korean government has focused on improving the utilization of public data and big data. However, as a result of this study, the use of public data and big data in South Korea is still insufficient. Yet, considering that the data utilized for this study was created in 2017, additional study using public data and big data is also required.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.6
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• pp.7-20
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• 2017

The advancement of cloud and big data and the considerable growth of traffic have increased the complexity and problems in the management inefficiency of existing networks. The software-defined networking (SDN) environment has been developed to solve this problem. SDN enables us to control network equipment through programming by separating the transmission and control functions of the equipment. Accordingly, several studies have been conducted to improve the performance of SDN controllers, such as the method of connecting existing legacy equipment with SDN, the packet management method for efficient data communication, and the method of distributing controller load in a centralized architecture. However, there is insufficient research on the control of SDN in terms of the quality of network-using applications. To support the establishment and change of the routing paths that meet the required network service quality, we require a mechanism to identify network requirements based on a contract for application network service quality and to collect information about the current network status and identify the violations of network service quality. This study proposes a method of identifying the quality violations of network paths through ontology to ensure the network service quality of applications and provide efficient services in an SDN environment.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.10
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• pp.299-308
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• 2023

As the spectrum shortage problem has accelerated by the emergence of various services, New Radio-Unlicensed (NR-U) has appeared, allowing users who communicated in licensed bands to communicate in unlicensed bands. However, NR-U network users reduce the performance of Wi-Fi network users who communicate in the same unlicensed band. In this paper, we aim to simultaneously maximize the fairness and throughput of the unlicensed band, where the NR-U network users and the WiFi network users coexist. First, we propose an optimal power allocation scheme based on Monte Carlo Policy Gradient of reinforcement learning to maximize the sum of rates of NR-U networks utilizing rate-splitting multiple access in unlicensed bands. Then, we propose a channel occupancy time division algorithm based on sequential Raiffa bargaining solution of game theory that can simultaneously maximize system throughput and fairness for the coexistence of NR-U and WiFi networks in the same unlicensed band. Simulation results show that the rate splitting multiple access shows better performance than the conventional multiple access technology by comparing the sum-rate when the result value is finally converged under the same transmission power. In addition, we compare the data transfer amount and fairness of NR-U network users, WiFi network users, and total system, and prove that the channel occupancy time division algorithm based on sequential Raiffa bargaining solution of this paper satisfies throughput and fairness at the same time than other algorithms.

• Journal of Broadcast Engineering
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• v.22 no.2
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• pp.214-233
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• 2017

For people with physical or sensory limitations, broadcasting is the main means of information acquisition and leisure. Recently, changes in the media environment, such as convergence of broadcasting and communication, digital mobile conversion of broadcasting, and active media usage behavior of users, make broadcasting accessibility of the disabled difficult, and as a result, the information gap between the disabled and the non-disabled is increasing. A notice on broadcasting rights for the disabled was enacted in consequence of the amendment of the Broadcasting Law in July 2011 and the web accessibility guideline became more effective with the amendment of the National Informatization Act in 2013 so that legal basis for the right of media access for the disabled was established. However, media services for them are still lacking quantitatively and qualitatively. In this study, we describe the present status of the audio description service for the visually impaired, and analyze the results of the questionnaire survey on the usage status, satisfaction and improvement requirements of the audio description service for 100 visually impaired people.

• Journal of Internet Computing and Services
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• v.11 no.2
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• pp.143-153
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• 2010

When providing high quality panoramic video across the Internet, mobile communications, and broadcasting areas, it requires a suitable video codec that satisfies both high-compression efficiency and random access functionality. The users must have high-compression efficiency in order to enable video streaming of high-volume panoramic data. Random access allows the user to move the viewpoint and direction freely. In this paper, we propose the parallel processing scheme under cell units in order to improve the performance of streaming service for large screen panoramic video in 10Mbps bandwidths based on H.264/AVC with high compression rate. This improved algorithm divides a screen composed of cells less than $256{\times}256$ in size, encodes it, and decodes it with the cells in the present view. At this point, encoding/decoding is parallel processed by the present cell units. Also, since the cells only included in the present view are packed and transmitted, the possible processing of not extricating blocks is proven by experiment.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.6
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• pp.11-18
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• 2009

In this paper, a hierarchical link allocation algorithm between mobile stations (MSs) and the corresponding base station (BS) by an optimal utilization of relay stations (RSs) is proposed to improve throughput of RS systems. In the proposed hierarchical algorithm, each RS operates cognitive radio functions to sense the degree of satisfaction in the quality of services (QoSs) and then selects the candidate set of MSs to have links with the RS. Such information is reported to the BS, where an auction process is performed to get an optimal allocation of communication links between the MSs and the BS. To maximize system throughput, the proposed auction algorithm is conducted upon bidding prices of communication links, considering both the co-channel interference (CCI) information shared among adjacent cells and the QoS enhancement information for each MS collected from RSs. The BS then switches the communication links of the auction winner MSs through the corresponding RS. The computer simulation shows that the proposed algorithm enhances the user QoS more than the conventional algorithm, especially for RS systems with more users requiring higher QoS. The proposed algorithm has also been proved to have more robust performance than the conventional one when the traffic load is higher and the CCI becomes stronger.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.227-245
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• 2023

As offline company and online·mobile startups meet in an untact shopping environment, competition among companies in untact shopping is increasing. In this situation, companies need their own clear strategy to create customer value. In particular, it is very important to focus on 'customer experience' to establish such a strategy in an untact shopping environment. Customer experience refers to all processes in which consumers meet and experience a company or brand at a touch point. In this processes consumers decide whether to continue to use the company and brand. In this situation, it is thought that it will be meaningful for research to examine the customer experience of untact shopping. Therefore, this study aimed to examine the customer experience of untact shopping, which is used by all generations after COVID-19, through experience quality, and to examine the impact on the expectation-confirmation Model of untact shopping. The results of this study are as follows. First, as a result of examining whether interaction quality, information quality, and outcome quality affect expectation-confirmation it was found that all qualities except interaction quality affect expectation matching. Second, as a result of examining whether interaction quality, information quality, and outcome quality affect perceived usefulness, it was found that all qualities except interaction quality had an effect. Next, as a result of applying the expectation confirmation model to the untact shopping environment and examining whether the expectation confirmation has an effect on use satisfaction, it was found that there was a positive effect. As a result of examining whether perceived usefulness affects use satisfaction, it was found to have a positive effect. As a result of examining whether perceived usefulness affects expectation confirmation, it was found that there is a positive effect. Finally, as a result of examining whether perceived usefulness affects the intention to continue using untact shopping, it was found to be positive. Next, as a result of examining the effect of use satisfaction on trust, it was found that there was a positive effect. Finally, as a result of investigating whether trust has an effect on the intention to continue using, it was found that there is a positive effect. Looking at the important results especially, information quality was found to have the greatest influence.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1741-1749
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• 2015

The purpose of this study was to investigate parents' perception and satisfaction of school food materials and supplier performance in Mokpo. To achieve these research objectives, a questionnaire was distributed to parents at 66 schools, and a total of 589 were used in the final analysis. The results of this study were as follows. First, satisfaction of school foodservice, showed the following scores: overall was 3.75, quality of food materials was 3.84, reliability of food suppliers was 3.80, education was 3.53, and information was 3.50. Second, 38.5% of parents participated in receiving school materials. Exactly 80.6% of parents showed intentions to participate. The most difficult thing for receiving materials was comparing quality of food materials (46.3%). Third, the most important factor cited for school food supplier was quality (62.3%) and sanitation and safety (24.1%). Forth, most parents were positive about the possibility of replacing foods used at school with environment friendly products. Local foods were cited for use in school foodservice (92.2%). The reasons were good quality (39.9%) and contribution to the local community (28.5%). In conclusion, parent's perception of school foodservice should increase to improve food material quality of school foodservice. Institutions for certifying are needed to offer high quality food materials at school foodservice and improved communication and education tool between the school and parents.