• Journal of KIISE:Software and Applications
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• v.34 no.5
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• pp.407-418
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• 2007

Service science is a new application area that implements services in an interdisciplinary area of management, economics, and engineering. Service systems provide functionalities of traditional software systems, moreover the functionalities are more intellectual in that they require dynamic context awareness, analysis, and decision making based on the recognized and analyzed contexts. However, conventional software development approaches do not sufficiently provide methods to model the service requirements and to design service-intensive systems. Therefore, there is a great demand on effective methodologies for developing service systems. In this paper, we compare traditional software systems with service-intensive systems in order to identify characteristics of the service systems. And, we propose a step-wise process to model service systems, in terms of architecture, components, and workflows. Then, we show a case study on an emergency handling system which is a type of living assistant systems. We believe that the proposed approach can be used in developing high-quality service systems effectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4287-4306
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• 2016

Network resilience provides an effective way to overcome the problem of network failure and is crucial to Internet protocol (IP) network management. As one of the main challenges in network resilience, recovering from link failure is important to maintain the constancy of packets being transmitted. However, existing failure recovery approaches do not handle the traffic engineering problem (e.g., tuning the routing-protocol parameters to optimize the rerouting traffic flow), which may cause serious congestions. Moreover, as the lack of QoS (quality of service) restrictions may lead to invalid rerouting traffic, the QoS requirements (e.g., bandwidth and delay) should also be taken into account when recovering the failed links. In this paper, we first develop a probabilistically correlated failure model that can accurately reflect the correlation between link failures, with which we can choose reliable backup paths (BPs). Then we construct a mathematical model for the failure recovery problem, which takes maximum rerouting traffic as the optimizing objective and the QoS requirements as the constraints. Moreover, we propose a heuristic algorithm for link failure recovery, which adopts the improved k shortest path algorithm to splice the single BP and supplies more protection resources for the links with higher priority. We also prove the correctness of the proposed algorithm. Moreover, the time and space complexity are also analyzed. Simulation results under NS2 show that the proposed algorithm improves the link failure recovery rate and increases the QoS satisfaction rate significantly.

• Korean Journal of Construction Engineering and Management
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• v.10 no.2
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• pp.55-64
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• 2009

In many developed countries, social infrastructure asset management has become an important issue for the effective operation and management, performance improvement, and providing better quality services. This paper describes infrastructure asset management practices in Korea and in the developed countries. Learning lessons from those countries and improve the asset management practices in Korea is the main theme of this paper. Considering the definition and basic structure of infrastructure asset management, authors have analyzed main concerns regarding infrastructure management, techniques, organizations (systems), and processes. The requirements and considerations are presented to overcome the limitations of current maintenance system. This paper will assist adopting infrastructure asset management in Korea and provide guide for the infrastructure maintenance.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.06a
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• pp.34-39
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• 2000

Today's size of production operations in the packaging paper sector I sconstantly increasing , featuring integral processing systems, high-speed paper machines, and the increased marketing of lower basis weight products. The risk factors involved in these large investments lie more than ever in the available furnish potential and ongoing requirements for further closure of water loops and lower operating costs. A comparison is drawn between recovered paper furnish mixtures used in European mills with regard to fibre properties, strength potential and contaminant content, Both the furnish situation and development trends in modern fluting and testliner machines are instigating concept changes in stock preparation, the approach flow as well as in process water and rejects technology. Developments are currently focussed for example on more efficient debris separation using fine slotted screening, optimized refining , more systematic process water management with loop separation and integral water clarification as well as more efficient removal of microstickies, fillers and fines through appropriate combination of rejects handling and water clarification processes. Product quality differentiation depends decisively on strength characteristics as a function of refining , fines removal , paper machine technology, and sizing . Maximum availability of today's high speed paper machines and , as a result, cost effective production can be ensured by optimum balancing of all subsystems with in the overall concept and by reliable control of problems with contaminants and deposits.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.66-77
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• 2021

Companies widely use survey to identify customer requirements, but the survey has some problems. First of all, the response is passive due to pre-designed questionnaire by companies which are the surveyor. Second, the surveyor needs to have good preliminary knowledge to improve the quality of the survey. On the other hand, text mining is an excellent way to compensate for the limitations of surveys. Recently, the importance of online review is steadily grown, and the enormous amount of text data has increased as Internet usage higher. Also, a technique to extract high-quality information from text data called Text Mining is improving. However, previous studies tend to focus on improving the accuracy of individual analytics techniques. This study proposes the methodology by combining several text mining techniques and has mainly three contributions. Firstly, able to extract information from text data without a preliminary design of the surveyor. Secondly, no need for prior knowledge to extract information. Lastly, this method provides quantitative sentiment score that can be used in decision-making.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.219-224
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• 2021

The convergence of various industries has removed the boundaries of software application fields and reduced the restrictions on convergence fields. Software requirements are diversified and they want to reconfigure software requirements in a fast cycle. Since various changes in requirements have to be accepted technically, research on methodologies and standards to increase the efficiency of software productivity and methods for standardizing and producing software are needed. In this study, we studied how the reusability and complexity of the software asset reconfiguration system appeared according to the developer's characteristics and environment to utilize the assets optimized in previous studies. At this time, we measured how the change in complexity according to the usability and asset composition method that appears according to the developer's characteristics appears, but there is a limit to the collected data, so it is necessary to secure the quality of the measured value through continuous data collection. In addition, an intelligent system application plan is needed to supplement the problem of context classification in the use stage of complex assets.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2219-2225
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• 2016

Mobile communication systems should be able to support multimedia traffics with limited transmit power due to the frequency reuse for maximizing the channel accommodation. Real-time data is very sensitive to delay, and they need to be transmitted instantly. On the other hand, non-real time data is less sensitive to delay, and their packet loss can be handled more flexibly. Therefore an adaptive resource management scheme is essentially required which enables to keep the minimal power allocated in the base station while guaranteeing the user requirements for QoE within a permissible range. Power-saving techniques are required in order to support multimedia services in the mobile networks because the power consumption increases greatly with the transmission rate increase. This paper proposes a novel scheme which enables to keep the allocated power minimal while guaranteeing the user requirements for QoE within a permissible range.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.1
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• pp.66-71
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• 2012

In this paper, using the bargaining game theory, we propose a bandwidth management scheme that allocates bandwidth in an efficient and proportionally fair manner between the service classes with different service requirements. Since the traffic input rates of the classes are asymmetric in most of the time, the proposed scheme allocates bandwidth in proportion to the traffic input rates to increase the bandwidth utilization while protecting the quality of service of a class against the excessive traffic input of the other classes. In addition, the proposed method considers the weights of classes so that the bandwidth is allocated differentially among the classes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.9
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• pp.2573-2589
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• 2023

As 5G mobile systems carry multiple services and applications, numerous user, and application types with varying quality of service requirements inside a single physical network infrastructure are the primary problem in constructing 5G networks. Radio Access Network (RAN) slicing is introduced as a way to solve these challenges. This research focuses on optimizing RAN slices within a singular physical cell for vehicle-to-everything (V2X) and enhanced mobile broadband (eMBB) UEs, highlighting the importance of adept resource management and allocation for the evolving landscape of 5G services. We put forth two unique strategies: one being offline network slicing, also referred to as standard network slicing, and the other being Online reinforcement learning (RL) network slicing. Both strategies aim to maximize network efficiency by gathering network model characteristics and augmenting radio resources for eMBB and V2X UEs. When compared to traditional network slicing, RL network slicing shows greater performance in the allocation and utilization of UE resources. These steps are taken to adapt to fluctuating traffic loads using RL strategies, with the ultimate objective of bolstering the efficiency of generic 5G services.

• Journal of the Korea Safety Management & Science
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• v.18 no.1
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• pp.99-109
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• 2016

The types and characteristics of services that airport service systems provide have recently been diversified and specialized to meet various needs of users and their travelling activities. A service for the mobility handicapped is one of the newly demanded services. However, current services for them, which are provided by most of the Korean airports, are not sufficient to satisfy their needs. Additionally, there exist a lot of constraints in the use of those services, which makes it difficult for the mobility handicapped to use them effectively. Another problem is that a lot of the mobility handicapped do not even know that airports now offer services specialized for them. Considering that Korean airports have been recognized as a top-level service provider for about decades, it can be claimed that such an inferior quality of services for the mobility handicapped should be urgently improved. With this issue in mind, this study aims to propose an approach to improving the quality of airport services for the mobility handicapped. Firstly, we examined the actual conditions of the services for the mobility handicapped and identified the limitations of the current services, based on the results of literature review and questionnaire survey against the mobility handicapped and stakeholders of the services currently provided. Then we established a set of design improvement requirements and suggested several ways to improve the services for the mobility handicapped. Finally, we pointed out several issues to be resolved to design better specialized services for the mobility handicapped.