• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.398-407
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• 2010

Due to increase of user requirement for various traffics and the advance of network technology, each distinct network has converge into FMC(Fixed Mobile Convergence) networks. However, we need to research the performance analysis of VoIP(Voice over Internet Protocol) in the FMC network to provide QoE for the voice user of FMC network. Therefore, this paper introduces the scenario which is the situation of voice quality degradation when a user uses VoIP to communicate with other users in the FMC network. Especially, this paper presents scenario in terms of the component of the network and finds the improvement point of voice quality. In the simulation results, three improvement points of voice quality are found as following: voice quality degradation by packet loss in the physical layer of the HSDPA network, by utilizing GGSN without QoS parameter mapping mechanism which is gateway between 3GPP and IP backbone, and by using non-QoS AP in the WLAN network.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.77-82
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• 2007

A novel DDoS (Distributed Denial-of-Service) defense technique, Exaustiveness-Based Detection, is proposed in this work. It dispenses with the network congestion and the unfairness between users of the Defense-by-Offense technique by incorporating a kind of simple Detect-and-Block scheme (user identification), still improving the effectiveness of the defense in comparison to the original Defense-by-Offense technique. It uses SYN cookies to identify users in the granularity of ip address and to prevent ip address spoofing by the attacker. There can be, however, some probability of false negative (denying service to good clients), if the attacker wisely adapt to the new technique by saving some portion of its bandwidth resource and later mimicking good clients. Quantitative analysis the requirement for the good clients to be safe from the false negative is provided and a procedure to design the server capacity is explained.

• Transactions of the KSME C: Technology and Education
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• v.1 no.2
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• pp.199-204
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• 2013

In this paper, a new system requirement management tool and its application on the Urban Transit Maglev Project were introduced. In most R&D projects on complexity system such as transportation system, Systems Engineering(SE) activities are included on each project, and SE teams are using commercial computer-based tools to perform the SE activities. Even though SE tools help to manage huge data and documents on engineering efficiently, but well-designed functions of SE tools which support SE activities are not sufficiently used on the whole process of system engineering. In order to computer-based SE tools are to be effectively used on project management, most engineers who takes engineering and coordination roles, at least sub-project managers should be familiar to the tool and could be easily use it, but usability of commercial SE tools are very difficult for normal engineers with no experience on SE activities and SE tools. To overcome this difficulty, we developed a new system requirement management tool considering each user's scenario on using engineering tools. The developed tool could not cover whole SE processes, but designed to perform requirement engineering such as system requirements(SRs) management, specification management, traceability management, SRs' verification activity management and so on. All the entities on SR database are inter-connected by pre-recognized traceabilities, so even non-specialists on SE can easily browse the database and find entities concern, and linked information such as interacted entities, legal or engineering constraints, coordination documents, status of development and verification and so on. Also functions for SR verification tools, TPM(Technical Performance Measure) tools, DB searching tools with traceability, and report generation tools are included on the system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.615-620
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• 2016

Improved quality of life has increased in a population with a high BMI (Body Mass Index). Accordingly, the development of a system for prevention of obesity management is required. Because a requirement for the prevention of obesity management system. This system has been developed to solve this problem and it is done by measuring the user information of the individual's body. The purpose of this paper is to understand the changes in your own BMI over the course of usage of this application and store the BMI in the database. This BMI data is expressed as a graph to the user and based on the BMI graph, the user is suggested to the type of exercise required by his body. The most appropriate exercise equipment's are shown to the user based on the BMI and also recommendations based on the historical data of other users with similar BMI. This system also recommends chronic diseases depending on blood sugar, blood pressure.

• The Journal of Korean Association of Computer Education
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• v.14 no.2
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• pp.75-82
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• 2011

Cloud computing is a computing paradigm that provides user's services anywhere, anytime in a virtualized form composed of large computing resources based on internet or intranet. In Cloud computing environments, reliability of system is impact factor because many applications handle large data. In this paper, we propose an adaptive scheduling technique based on reliability with fault tolerance that manages resource variable and resolves problems(change of user's requirement, failure occurrence) in Cloud computing environment. Futhermore, we verified the performance of the proposed scheduling through experiments in CloudSim Simulation.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.1 s.9
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• pp.41-55
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• 1997

An improved model of 'use' or 'region' districting(or regional zoning) scheme has been proposed. GIS based prototype model of managing the semi-agricultural region is implemented in a PC based platform focusing the Yongin, Kyonggi-Do area. Throughout the process of users' requirement analysis, database design, and user interface design, it has been shown that the integrated system may shed light on the prospective usage by the city or county government officials regardless of the short functionalities and user interface. This study aims first at identifying the needs in the area of districting at local level and at suggesting a basic framework of database design and system implementation in regard to region districting. The ARC/INFO, ArcView/Avenue based PC-based decision supports system presented herein is hoped to be supplemented with the inclusion of time factor in its database to cover and reflect the temporal variations associated with the plans.

• The KIPS Transactions:PartD
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• v.16D no.3
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• pp.361-370
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• 2009

Recently, the most mobile application software developers are being faced by short developing time (fast time-to-market), various requirements and requirement changes. In order to overcome the environment, developer should support user friendly GUI and assure the quality from the early developing process using GUI test method. This paper proposes a test method and tool for mobile software GUI, which reduces test time and supports comfortable test environment by user oriented UI design. We implemented a tool based on test scenarios based image flow for high testing accuracy and test case reusability. And the results show the characteristics of the method compared to the existing tools.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1605-1608
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• 2003

Today, E-Business develop because, Internet diffuse rapidly. Variety function and excellence performance needs for changeable user's requirement. So, EJB comes Component's addition and modify. For Component adds Function, Existing System modifies all of the source code. In EJB Component System, but, modifies simple source code. But, Today's System don't have cleary way that assembly component and design system. This Paper used design pattern for maintain of the component. this paper describes EJB Design Pattern using Abstract Factory Pattern. And EJB Component that used Pattern, decribes advantage and disavantage.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.159-162
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• 2002

A software, called touch-one, is developed about the determination of short-circuit values and protective co-ordination in power system. The used solution algorithm reviewed intensively, and the protective co-ordination determination technique presented by using the circuit-breaker's current-limitation characteristic. The protective coordination concerns the behaviour of two devices placed in series in an electrical network, with a short-circuit downstream circuit-breaker. It has two basic principles: First, discrimination which is an increasing requirement of low voltage electrical distribution systems. Second, which is less well known: cascading, which consists of installing a device, whose breaking capacity is less than the three-phase short-circuit current at its terminals and helped by main circuit-breaker. With this software, we can construct a electric-power system which is reliable and economic according to user's purpose.

• IEMEK Journal of Embedded Systems and Applications
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• v.4 no.2
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• pp.50-54
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• 2009

In this paper, we address a novel system-level power management technique which is specifically targeted for an ARM 11 MPCore system. Our proposed solution is a DPM technique which includes process monitoring, real time power analysis, and policy application to reduce the power consumption while meeting the performance requirement. One of the main contributions of this paper is that we systematically infer QoS requirements of processes without getting any additional information from the application. When multiple processes are running under various user level policies, priorities of the policy application are determined in such a way that the overall system performance is maintained while power consumption is effectively managed. Experimental results show that our DPM technique is very effective in reducing power consumption without violating system's QoS requirements.