• Korean journal of food and cookery science
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• v.26 no.1
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• pp.72-78
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• 2010

This study aimed to obtain basic data toward fostering understanding and interest in local foods, to the overall end of enhancing development and popularization of such foods. It also gives direction toward promotion of local food by researching attitudes toward local foods and viewpoints on requirements for improvement of such, among university students living in the Daegu-Kyungbuk area. The results of analyzing perceptional scores for native local foods in Kyungbuk by characteristics t showed statistically significant differences according to sex and duration of residence in Kyungbuk. Obstacles to the promotion of local foods include lack of marketing, lack of specialized restaurants, lack of knowledge, lack of menus, lack of generalization, and high price. The results of analyzing viewpoints on requirements for improved perception of local foods, there were statistically significant differences in active advertisement and marketing, diversity of local foods, and duration of dwelling.

• Journal of Communications and Networks
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• v.12 no.4
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• pp.346-357
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• 2010

Opportunistic scheduling provides the capability of resource management in wireless networks by taking advantage of multiuser diversity and by allowing delay variation in delivering data packets. It generally aims to maximize system throughput or guarantee fairness and quality of service (QoS) requirements. In this paper, we develop an extended proportional fair (PF) scheduling policy that can statistically guarantee three kinds of QoS. The scheduling policy is derived by solving the optimization problems in an ideal system according to QoS constraints. We prove that the practical version of the scheduling policy is optimal in opportunistic scheduling systems. As each scheduling policy has some parameters, we also consider practical parameter adaptation algorithms that require low implementation complexity and show their convergences mathematically. Through simulations, we confirm that our proposed schedulers show good fairness performance in addition to guaranteeing each user's QoS requirements.

• Journal of the military operations research society of Korea
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• v.17 no.1
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• pp.43-60
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• 1991

Consider N queues without arrivals and with m identical servers. All jobs are independent and service requirements of jobs in a queue are i.i.d. random variables. At any time only one server may be assigned to a queue and switching between queues are allowed. A unit cost is imposed per job per unit time. The objective is to minimized the expected total cost. An flow approximation model is considered and an upperbound for the percentage error of best nonswitching policies to an optimal policy is found. It is shown that the best nonswitching policy is not worse than $11\%$ of an optimal policy For the stochastic model, we consider the case in which the service requirements of all jobs are i.i.d. with an exponential distribution. A longest first policy is shown to be optimal and a worst case analysis shows that the nonswitching policy which starts with the longest queues is not worse than $11\%$ of the optimal policy.

• ETRI Journal
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• v.18 no.4
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• pp.229-244
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• 1997

Realization of the economical, reliable, and efficient ATM interface block becomes an important key to development of the ATM switching system when we consider new issues raised recently. In this paper, we summarize requirements for the ATM interface block and present the UNI (User Network Interface)/NNI (Network Node Interface) architecture to meet these requirements. We also evaluate the performance of the multiplexer adopting the various multiplexing schemes and service disciplines. For ATM UNI/NNI interface technologies, we have developed a new policing device using the priority encoding scheme. It can reduce the decision time for policing significantly. We have also designed a new spacer that can space out the clumped cell stream almost perfectly. This algorithm guarantees more than 99 % conformance to the negotiated peak cell rate. Finally, we propose the interface architecture for accommodation of the ABR (Available Bit Rate) transfer capability. The proposed structure that performs virtual source and virtual destination functions as well as a switch algorithm can efficiently accommodate the ABR service.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2034-2039
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• 2010

As a mass transportation system, a railway contains potential risks that may result in a high death rate and property losses. Accordingly, Railroad Safety Technology R&D Corps. is adopting the plan of the construction of Railway Safety Test Facilities as a part of the Railway Total Safety Project to enhance the railway safety, and carrying out researches on effective project management methods with Systems Engineering techniques. When a system or a service is realized, such as the Railway Total Safety Project, it needs to be verified by requirements and the process of verification is to check whether customers/stakeholders requirements have been properly transformed into a system or a service. Recently, building the standardized verification system up could be the solution to reduce possible system-failed risks. To support that, we propose the more effectual verification method of constructing the Railway Safety Test Facilities applying the systems engineering tool to the research.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.2
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• pp.153-162
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• 2006

Customer satisfaction is an ever-growing concern of management throughout the world. To find the way to increase customer satisfaction, we must understand customer requirements. Kano distinguishes between three types of product requirements (must-be, one-dimensional, attractive requirement) which influence customer satisfaction in different ways when met. In this paper, potential customer satisfaction improvement (PCSI) index was developed using Kano model and CS coefficient. Timko has developed customer satisfaction (CS) coefficient based on Kano model. The PCSI index represents how much a service feature can increase the degree of customer satisfaction when the service feature is fully fulfilled. In order to explain the meaning of PCSI index, a case syudy of a Family Restaurant is done. It is also discussed how to use the index strategically.

• Journal of Korea Port Economic Association
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• v.22 no.2
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• pp.19-33
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• 2006

The efficiency and effectiveness of freight transportation within and across Northeast Asia playa key role to achieve competitive advantages against other competing hubs in this area. However, the majority of local freight has been carried by ground transportation and the share of costal shipping has been decreasing for its transportational complexity and poor cargo works. In this paper, we discuss the prerequisites of efficient cargo linkage system from the perspectives of road, rail, ocean, and the service providers. Specifically, we identify that the balanced capacity of road/rail transportation system with costal freight system is a crucial component for facilitating coastal shipping. Other requirements such as the efficient on-dock container yard (ODCY), dedicated ports and ships, and the service provider of door-to-door transportation for short sea shipping are highlighted in order to secure the serviceability and availability of streamlined costal shipping. Further, we elaborate these requirements to facilitate costal cargo shipping in Korea.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1566-1573
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• 2008

Generally, a system or service is verified by requirements if it has met them in transforming customer requirements into a system or service. But as the national research and development projects to develope safety systems or standards or process in railway system domain, it can be quite limiting that the product or systems verification process presented the international or industrial standards to be applied. This paper has analyzed and made up for the general verification process and presented the effective and efficient verification process about safety system, safety standard, process, and safety documents and the methods to manage the outcomes of verification process.

• Electronics and Telecommunications Trends
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• v.36 no.4
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• pp.1-12
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• 2021

The competition to lead the next generation of mobile technologies, 6G, is underway while the deployment of 5G has not been implemented worldwide. ITU-R plans to develop technical requirements and standards after completing the 6G Vision by 2023. It can be considered too early to have a concrete view of the 6G core network architecture from this timeline. However, major stakeholders have started making their presence felt by publishing their views. From updated analysis on the technology and service trends proposed, we present a list of research directions on 6G core network from several perspectives: distribution of network functions to nearer edge locations; future fixed-mobile convergence, including low earth orbit satellites; highly-precise QoS guarantee; supporting an extremely wide variety of service requirements; AI-native automation and intelligence; and aligning with the evolution of radio access network.

• Smart Media Journal
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• v.11 no.5
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• pp.82-90
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• 2022

Along with the growing popularity of 5G technology, providing flexible and personalized network services suitable for requirements of customers has also become a lucrative venture and business key for network service providers. Therefore, dynamic network provisioning is needed to help network service providers. Moreover, increasing user demand for network services meets specific requirements of users, including location, usage duration, and QoS. In this paper, a routing algorithm, which makes routing decisions using Reinforcement Learning (RL) based on the information about link stability, is proposed and called Link Stability aware Reinforcement Learning (LSRL) routing. To evaluate this algorithm, several mininet-based experiments with various network settings were conducted. As a result, it was observed that the proposed method accepts more requests through the evaluation than the past link annotated shorted path algorithm and it was demonstrated that the proposed approach is an appealing solution for dynamic network provisioning routing.