• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11C
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• pp.940-948
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• 2008

This paper presents a low-power, low-complexity design and implementation results of a high speed multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) wireless LAN (WLAN) baseband processor. The proposed processor is composed of the physical layer convergence procedure (PLCP) processor and physical medium dependent (PMD) processor, which have been optimized to have low-power and reduced-complexity architecture. It was designed in a hardware description language (HDL) and synthesized to gate-level circuits using 0.18um CMOS standard cell library. As a result, the proposed TX-PLCP processor reduced the power consumption by as much as 81% over the bit-level operation architecture. Also, the proposed MIMO symbol detector reduced the hardware complexity by 18% over the conventional SQRD-based architecture with division circuits and square root operations.

• Journal of Ship and Ocean Technology
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• v.12 no.1
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• pp.16-27
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• 2008

The interaction between advancing ships and the waves generated by them plays important roles in wave resistances and ship motions. Wave breaking phenomena near the ship bow at different speeds are investigated both numerically and experimentally. Numerical simulations of free surface profiles near the fore bodies of ships are performed and visualized to grasp the general trend or the mechanism of wave breaking phenomena from moderate waves rather than concentrating on local chaotic irregularities as ship speeds increase. Navier-Stokes equations are differentiated based on the finite difference method. The Marker and Cell (MAC) Method and Marker-Density Method are employed, and they are compared for the description of free surface conditions associated with the governing equations. Extra effort has been directed toward the realization of extremely complex free surface conditions at wave breaking. For this purpose, the air-water interface is treated with marker density, which is used for two layer flows of fluids with different properties. Adaptation schemes and refinement of the numerical grid system are also used at local complex flows to improve the accuracy of the solutions. In addition to numerical simulations, various model tests are performed in a ship model towing tank. The results are compared with numerical calculations for verification and for realizing better, more efficient research performance. It is expected that the present research results regarding wave breaking and the geometry of the fore body of ship will facilitate better hull form design productivity at the preliminary ship design stage, especially in the case of small and fast ship design. Also, the obtained knowledge on the impact due to the interaction of breaking waves and an advancing hull surface is expected to be applicable to investigation of the ship bow slamming problem as a specific application.

• Journal of the Korea Society for Simulation
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• v.20 no.3
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• pp.101-109
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• 2011

M&S in the field of national defense is a battle system has been highly spotlighted for obtaining weapon systems, analyzing and experimentation of battle effects to reduce costs, time, and risks. It is classified as Campaign, Mission, Engagement, and Engineering levels by detail of description. In engagements, many situations on the battle field which are really unpredictable are required to be considered on the view of diverse tactics. Thus, engagement simulation is in demand to use for forecasting real-world battle situations by inserting various components which consists of real engaging situations into virtual local battle field. While developing the engagement simulation, adopting the concept of agent-based simulation gives it benefits which are improved autonomy, composability, and reusability of entities. It means reducing the time, cost and effort to develop the simulations. This paper concentrates on the framework of multi-agent based engagement simulation using Cougaar Architecture.

• Journal of Information Technology and Architecture
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• v.9 no.3
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• pp.275-285
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• 2012

DIFs (Data Interchange Formats) are needed to enhance interoperability of physically distributed organizations in SBA (Simulation Based Acquisition) process. DIFs play a role as a template of DPDs (Distributed Product Descriptions) and provide capability to use information directly without data format interchange process by allowing access to DPDs, which include various information and M&S (Modeling & Simulation) resources. This characteristic is essential for interoperability in ICE (Integrated Collaborative Environment) based SBA. This paper proposes a framework for the DIF and outputs from each phase of acquisition process for configuration data related to design and manufacturing in SBA process - Conceptual Data Model, Logical Data Model, Physical Data Model and Physical DIF based on XML. Finally, we propose the DIF model architecture and demonstrate the implementation of DIF example based on it.

• Journal of Intelligence and Information Systems
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• v.11 no.2
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• pp.105-121
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• 2005

To realize a ubiquitous logistics management system using the smart object of Electronic Product Code(EPC) enabled RFID tag, the design and management of RFID Information Service is very important. RFID Information Service searches, transfers and responds to the other's PML request, but Physical Markup Language (PML) data management between trading system elements has issues of standardization of PML data description and processing, and problems of data traffic and communication time overload because of the innate distributed characteristics. As a complementary study, this research analyzes the usage patterns and data types of PML. On that analysis we provide a design of the distributed RFID Information Service architecture of PML data management that is using DB middleware. Standalone and Integrated type of RFID IS were proposed.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.224-230
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• 2019

In this paper, a new multiple servers conference service system using media control channel/distributed conference manipulation architecture has been presented. This conference service system can handle loads effectively from many conference participants. In this suggested architecture, media control channels are established between conference server, and distributed conference manipulation messages for distributing system loads are exchanged through this channels. These messages are transported between servers using media control channel created after stable transport sessions, and can be used to process server loads according to participants effectively. So this method can be used to implement large scale conference service system. For these purposes, formats of distributed conference manipulation messages which transmitted through media control channels are designed. and messages exchange procedures between conference servers are also presented. The performance of the proposed conference service system has been analysed by experiments, and the results show that the performances are improved according to participants.

• Journal of Environmental Impact Assessment
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• v.6 no.2
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• pp.165-180
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• 1997

Mitigation measures in EIS are the important factors in the effectiveness of EIS. This paper analyzed the content of mitigation measures described in the 30 EISs selected, using 7 analysis items in order to discover the degree of effectiveness of mitigation measures. 30 EISs used in this study were selected through variance maximization strategy, and the 7 analysis items were; 1) thoroughness of mitigation content, 2) quantification of mitigation content, 3) explicit description of mitigation effect, 4) likelihood of mitigation effect, 5) impacted area of mitigation effect, 6) time frame of mitigation effect, and 7) environmental impact of mitigation measures. The results showed that the effectiveness of mitigation measures in the analyzed EISs was relatively low both in the appropriateness and in the specificity. It was suggested that in order to improve the appropriateness of EIS as a decision making tool, the effect of mitigation measures, as well as the mitigation measures themselves, should be studied and described more thoroughly and specifically.

• Convergence Security Journal
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• v.4 no.3
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• pp.27-35
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• 2004

A current trend in telecommunication is the convergence of wireless communication and computer network technologies, and the emergence of wireless application protocol(WAP) devices is an example. Computer system managers are often requested to solve urgent system problems. Many times, they cannot access a computer to perform remote system management tasks. Aiming at solving this problem, this paper presents a novel tool for system management that uses a WAP interface, and focuses on the description of the architecture and the associated application modules.

• Journal of the Korea Institute of Building Construction
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• v.12 no.1
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• pp.98-107
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• 2012

Reinforcing bars (rebar) comprise an integral part of a concrete structure, and play a major role in the safety and durability of the building. However, the actual placement or installation of rebar is not planned and controlled by the detailer. Recently, 4D simulations, using 3D model and scheduling software, have been used to improve the efficiency of the construction phrase. However, 4D simulators have not been introduced at the detailed level of work, such as rebar placement. Therefore, this paper suggests a BIM-based simulator for rebar placement to determine the sequence with which rebar is placed into the form. The system using Autodesk Revit API automatically generates rebar placement plans for a building structure, and labels the placement sequence of each individual bar or set of bars with ascending numbers. The placement sequence is then visualized using Autodesk Revit Structure 2012. This paper provides a short description of a field assessment and limits.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.509-512
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• 2005

The aim of this work is to design a real-time reusable image enhancement architecture for video signals, based on a spatial processing of the video sequence. The VHDL hardware description language has been used in order to make possible a top-down design methodology. By adding proposed algorithms to the LPR(License Plate Recognition) system, the system is implemented with reliability and safety on a rainy day. Spartan-2E XC2s300E is used as implementation platforms for real-time system.