• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.238-256
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• 2016

Modern web services have been broadly deployed on the Internet. Most of these services use multi-tier architecture for flexible scaling and software reusability. However, managing the performance of multi-tier web services under dynamic and unpredictable workload, and different resource demands in each tier is a critical problem for a service provider. When offering quality of service assurance with least resource usage costs, web service providers should adopt self-adaptive resource provisioning in each tier. Recently, a number of rule- and model-based approaches have been designed for dynamic resource management in virtualized data centers. This survey investigates the challenges of resource provisioning and provides a competing assessment on the existing approaches. After the evaluation of their benefits and drawbacks, the new research direction to improve the efficiency of resource management and recommendations are introduced.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.187-189
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• 2000

Nowadays, efforts are in progress for the standardization of CORBAbased telecommunication network management framework. To implement a network management system based on the framework completely, CORBA ORB and some of CORBA service should be installed in the element. And then, there must be the naming tree, which correspond to the containment relationships between components in the network element. If we use conventional OMG naming service to form the naming tree, all MOs, a software fragmenthat corresponds to each component in a system, should be instantiated. However, the network element is usually a kind of limited resource system, which cannot provide sufficient resources for applications run on it. Hence, instantiatingall MOs can cause problems for that kind of system, This paper presents Smart Naming Service architecture as a solution to the problem.

• Journal of the Korea Safety Management & Science
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• v.9 no.6
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• pp.105-112
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• 2007

The era of express train in Korea has come since April in 2004. The KTX(Korea Train Express) which has introduced the technology of TGV of France is regraded as good as the ICE of Germany or Shinkansen of Japanese in its hardware aspects. However there are still many things to be improved in its software aspects such as the quality of services, since the new express railway system is in the early beginning stage. To improve the quality of services, we should first measure and analyze the current level of the service quality. Using SERVQUAL model, the service level of KTX is measured and analyzed in this paper. Issues on how to improve the service quality are discussed based on the measurement and analysis.

• Journal of the Korea Society of Computer and Information
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• v.24 no.2
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• pp.149-155
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• 2019

The purpose of this paper is to design a survey of passenger satisfaction by using the Likert five-scale for the passengers of Incheon International Airport and Beijing Capital International Airport in China, and to combine the actual service situation of the airports in the two countries, using SPSS statistical software. Analyze and process statistics. Using the questionnaire survey method and exploratory factor analysis method, the airport service quality is analyzed to analyze the impact model of customer satisfaction. We will sort out the customer satisfaction with the two airports, compare and analyze the gaps in airport services between the two countries, and identify problems to formulate optimization and improvement plans.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.173-182
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• 2020

The purpose of this paper is to study the influence of new service methods of "artificial intelligence (AI) + medical cosmetology", a new service means, on customers' purchase intentions. To AI medical beauty APP sales as an empirical study. This paper designed Likert seven scale to investigate, using SPSS 24.0 statistical analysis software and AMOS24.0 structural equation software to analyze the survey data. The analysis method uses reliability analysis, validity analysis, and construct equation model analysis. Through empirical research, the following results can be found, 1. The system quality of AI medical beauty app will have a positive impact on perceived usefulness and perceived ease of use. 2. The information quality of AI medical beauty app will have a positive impact on perceived ease of use and perceived usefulness. 3. The service quality of AI medical beauty app will have a positive impact on perceived ease of use and perceived usefulness 4. Consumers' perceived ease of use has a positive impact on perceived usefulness and purchase intention. 5. The usefulness of consumers' notification has a positive effect on purchase intention.

• Journal of KIISE:Software and Applications
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• v.34 no.9
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• pp.848-856
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• 2007

The curriculum for teacher ICT in-service training has several problems in terms of running and managing training content. The majority part of the program consist of teaming software application manual. Additionally, the program is not organized and some contents overlap. Furthermore teachers are not obliged to participate in training. Especially, it needs to be revised because it is many difference between revised ICT curriculum and 'ICT skill standard for teacher(ISST)'. This study investigates the current curriculum for teacher ICT in-service training, analyzes problems in running and managing training content, and suggests need for revising the curriculum for teacher ICT in-service training.

• Journal of KIISE:Software and Applications
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• v.35 no.3
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• pp.137-148
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• 2008

Services system which has been emerging as a new way of application development utilizes services as fundamental units for developing a system. Services system can offer services within web environment as well as the ubiquitous environment where mobile devices are connected to wired or wireless network. In order to provide the functionality that meets users' requirements, the most appropriate service should be selected among candidate services by taking requests and context information into account. Therefore, it is important that the service system should provide services to users by dynamically adapting to users' requirements and context information. Since different users request same functionality with different context information, one service can be differently offered to users so that variability can happen to the service systems. Most researches on context-aware systems have a tendency to solve dynamic adaptation by using more or less ad hoc manner In this paper, we consider various types of services which are performed according to context information as variability and propose adaptable architecture by applying concepts of product line architecture in order to deal with variabilities systematically.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1914-1924
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• 2016

In this paper, considering virtualized Evolved Packet Core(vEPC) network for 5G mobile network, we propose architecture for supporting Service Function Chaining(SFC) in 5G mobile network. Using SFC in 5G network, dynamic path configuration and providing network services based on subscriber and traffic information. SFC technology provides logical ordered set of network functions and delivers packet through providing logical path over the physical network. Based on the perspective of 5G core network in distributed manner, we design hierarchical SFC architecture to manage SFC for global path including vEPC and SGi-LAN network, and internal path between virtualized network functions in each cloud. In this paper, we define architecture and call flow for establishing data path using SFC. Finally, we design testbed architecture for real implementation based on open source software.

• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.14-23
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• 2014

This paper proposed controlling methods for SDN(Software Defined Network) based multiple radio access technology as the solutions of following two issues which were mainly occurred by explosive increasing of video traffic. The first one is a requirement for traffic off-loading caused by 3rd-party video service providers from the mobile network operator's viewpoint. The other one is a provision of high-speed video contents transmission services with low price. Furthermore, the performance evaluation was also conducted on the real test-bed which is composed of OpenStack cloud and SDN technology such as OpenFlow and Open vSwitch. A virtual machine running on the OpenStack provide a video service and the terminal which is able to use multiple radio access technology supports two 2.4GHz WLANs(Wireless Local Area Network) and three 5GHz WLANs, concurrently. Finally, we can get 820Mbps of the maximum transmission speed by using that five WLAN links for the single service at the same time.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1153-1160
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• 2021

This paper proposes a routing algorithm that determines the optimal path using deep reinforcement learning in software-defined networks. The deep reinforcement learning model for learning is based on DQN, the inputs are the current network state, source, and destination nodes, and the output returns a list of routes from source to destination. The routing task is defined as a discrete control problem, and the quality of service parameters for routing consider delay, bandwidth, and loss rate. The routing agent classifies the appropriate service class according to the user's quality of service profile, and converts the service class that can be provided for each link from the current network state collected from the SDN. Based on this converted information, it learns to select a route that satisfies the required service level from the source to the destination. The simulation results indicated that if the proposed algorithm proceeds with a certain episode, the correct path is selected and the learning is successfully performed.