• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.103-110
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• 2010

This paper addressed the implementation of the systematic performance analysis of Quality of Service (QoS) by using OPNET simulator in the interworking architecture of IEEE 802.16e (mobile WiMAX) and IEEE 802.11e (WLAN) wireless network. Four simulation cases were provided in OPNET simulator and a voice traffic was simulated with various performance metrics, such as Mean Opinion Score (MOS), end-to-end delay and packet transmission ratio. Based on the simulation results, the MOS value presented better in WiMAX to WiMAX case compared to others in both static and mobility case. Meanwhile, end-to-end delay was not greatly affected by mobility in four cases. However, mobility was affected much in MOS value and packet transmission ratio in WLAN to WLAN case than in others.

• Korean Journal of Construction Engineering and Management
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• v.7 no.5
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• pp.94-104
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• 2006

The changed Korean government law associated with the public apartment housing supply, so called the $^{\circ}{\AE}$Apartment Sales Price $Cap^{\circ}{\phi}$, requires new system for estimating construction cost in order to set appropriate price. A model apartment project was carefully designed and its construction cost were analyzed in many different ways. Based on the analyses outcomes, 1,028,000 Won/m2 (excluding cost for underground parking lot) is the most appropriate Price Cap for a smaller than $85{\beta}{\geq}$ apartment unit. Further, it was revealed that the price have to be adjusted reflecting such factors as underground size; structural system; external complex quality; and consumer preferences. Findings from this study will enable the Korean government to realize faster and better application of the related laws. The methodology for obtaining appropriate apartment construction cost will also benefit for future researchers.

• Journal of Digital Contents Society
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• v.19 no.1
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• pp.67-73
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• 2018

Researchers have increased their interest in effectively managing the disaster that appear in large scale and complex form. There are two types of disaster information, which are unstructured text data and structured data. Unstructured text data usually refers to text documents that have been referenced by disaster management personnel such as disaster manuals and related regulations, while structured data refers to various disaster information build in the disaster related organization system. This paper proposes a methodology of constructing a disaster information sharing system that enables joint use of disaster related organizations through the establishment of a mutual linkage system by utilizing both unstructured and structured form of disaster information. Especially, Based on the linkage information between structured earthquake information in earthquake related system and earthquake manuals and countermeasures against earthquake disaster, we propose a service that provides the necessary information for earthquake management. It is expected that the task manager will perform effective earthquake state management by acquiring the integrated structured and unstructured earthquake information of the ministries and related organizations.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.49-56
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• 2015

Korea government has established clear cost estimation standard based on a survey of e-learning contents development cost and presented 'e-Learning Contents Development Cost Estimation Guidelines' that reflect the characteristics of the e-learning industry. However, if there is no institutional support, this guideline and system fails to achieve the purposes and objectives. And it is likely to be facing a dead document. Therefore, the policy foundation is required. This study suggested the following policy; stepwise activation of cost estimation standard, enact announcement and periodically adjustment of cost estimation standard, installation and operation of cost estimation standard operational committee, conjunction with the e-learning industry survey, cultural diffusion of co-owned copyright, systematic monitoring of the e-learning contents development process, research on activating policy of cost estimation standard, conjunction with the standard contract for enhancing policy effectiveness.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.441-450
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• 2011

Recent construction projects consist of large and complex facilities, which project management information system (PMIS) is used for managing construction cost and schedule. The ministry of land, transport and maritime affairs (MLTM) is using a continuous acquisition and life-cycle support (CALS) system for managing the public construction projects. This study attempts to survey some problems of the CALS system in practical application, and then suggests the new functions to improve practical application of the CALS system. All functions in each menu were analyzed in the practical application aspect. All projects ordered from MLTM should use the CALS system as a PMIS, but the practical application is limited in partial functions and special working group. And the utilization of system is focused on simple tasks and report process. One of main reason is that the system is using numerical data rather than graphical data. This study suggests new functions and a visualized management method that can improve the practical applicability using a 4D object in each current functions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.729-732
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• 2010

The present study has been motivated by the development of a reliable numerical methodology for simulation of kerosene/LOx coaxial swirl injectors. To deal with thermodynamic non-ideality and anomalies of transport properties pronounced at supercritical pressures, a set of subroutine libraries has been constructed based on the cubic equations of state, and applied to an existing flamelet analysis code. For computational efficiency, two-dimensional axisymmetric RANS formulation with swirl was adopted and validated successfully against an isothermal coaxial swirling jet. For the actual problem with high pressure combustion, however, numerical results show that the RANS models yield excessive production of turbulence probably due to high density gradient magnitude in the vicinity of mixing layer of swirling film flow, and imply strongly further improvement of the turbulence models.

• Journal of the Korea Society for Simulation
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• v.21 no.1
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• pp.89-96
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• 2012

Recent modeling and simulation technologies are being used in various fields, especially in the field of military simulation-based acquisition (Simulation Based Acquisition) is recognized as an essential policy. In test and evaluation phase of the SBA process, to build a simulation-based T&E(test and evaluation) environment is needed when T&E cannot be carried by real weapon system. To improve efficiency and reliability for T&E, interoperability, reusability and reliability for T&E equipments and systems are important. In this study, we propose applying simulation framework for efficienct test and applying VV&A process for reliable evaluation. We describes the characteristics of the development process, the actual test cases and the results of evaluation. Finally utilization plan and the future direction of research is described.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.25-37
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• 2014

Recently, our local governments are conducting the introduction of tram system because it is recognized as an effective public transit that can solve a traffic jam in downtown, decreasing public transit share and environmental issues in world wide cities. We developed the Active Priority Control Strategy to efficiently operate a tram in our existing traffic signal system. This study organized the tram system for operating the Active Priority Signal Control, developed the algorithm that calculates a tram-stop dwell time in order to pass the downstream intersection without a stop. The dwell time is determined by arrival time at tram-stop, downstream signal time, and the location of a opposite tram, it can be reduced by choosing the optimal one among Signal Priority Controls. Using the VISSIM and VISVAP model, we conducted a simulation test for the city of Chang-won that it is expected to install a tram system. It showed that a developed signal control strategy is effective to prevent a tram's stop in intersections, to reduce a tram's travel time.

• Survey Research
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• v.11 no.1
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• pp.107-121
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• 2010

The purpose of this paper is to design and implement a Computer Assisted Personal Interviewing (CAPI) system for Panel Survey of Employment for the Disabled (PSED) using Blaise software developed by Statistics Netherlands which is a powerful and flexible system used for computer-assisted survey processing. CAPI system for PSED is consisted of three parts, which are survey management program, electronic questionnaire program, and postprocessing program. These programs are constructed with modular approach and are integrated into CAPI system. The developed software is highlighted in its reusability which results in the improved efficiency and reduced cost of software maintenance. CAPI system for PSED proved its effectiveness in carrying out the survey by guaranteeing correctness of survey data, improved timeliness of survey, easy reforming the questionnaires, easy control on the interviewers, and rapid data processing in spite of the complexity of PSED.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.75-87
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• 2011

Tactical Data Links are standardized radio communication data links for military armed forces and used to transmit and receive data. Because they are the core elements of achieving information superiority in a NCW environment, various kinds of TDL are used by the Korean armed forces. Operating various types of TDL is very helpful in getting more information; however, at the same time, it is hard to integrate and make them co-operate with other TDLs or C4ISR systems. In this paper, we propose a XML based messaging system to make various types of TDL interoperable in a NCW environment. For the messaging system between TDL and C4ISR systems, we define XML message processing interfaces and suggest binary XML for serialization to save transmission loads over constrained military communication bandwidth. Our experiment results show that the TDL message can be transformed into generalized XML data that is interoperable with other TDLs and binary XML serialization, and it saves parsing and transmission time.