• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.102-107
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• 2009

Window system is an essential component for lighting, ventilation and thermal environment in buildings. Moreover, as balcony extension in apartment houses become legalized, the performance requirements of window systems in balcony space are getting complicated. However, at this moment, five properties of the windows are used to represent the performance aspects of the system, including wind resistance, air tightness, water tightness, sound insulation, thermal resistance. And such single properties are not capable to express the performance of a space with the window systems in terms of performance concept. A performance analysis with wholistic approach is required to see the effect of the window system in built environment. Thus, performance-based approach should be established, which will be able to evaluate the goal/function and comfort of occupants/owners. As the first step to develop the performance indicator for the window systme for balcony space, this study conducts a survey to find the required performance aspects. A complete set of performance-based indicators will be developed with verification methods in the later stage of research.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.5
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• pp.1881-1903
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• 2015

With the fast-developing of mobile terminals, positioning techniques based on fingerprinting method draws attention from many researchers even world famous companies. To conquer some shortcomings of the existing fingerprinting systems and further improve its performance, we propose a radio map building and updating technique, which is able to customize the spatial and temporal dependency of radio maps. The method includes indoor propagation and penetration modeling and the analysis of human traffic. Based on the combination of Ray-Tracing Algorithm, Finite-Different Time-Domain and Rough Set Theory, the approach of indoor propagation modeling accurately represents the spatial dependency of the radio map. In terms of temporal dependency, we specifically study the factor of moving people in the interest area. With measurement and statistics, the factor of human traffic is introduced as the temporal updating component. We improve our existing indoor positioning system with the proposed building and updating method, and compare the localization accuracy. The results show that the enhanced system can conquer the influence caused by moving people, and maintain the confidence probability stable during week, which enhance the actual availability and robustness of fingerprinting-based indoor positioning system.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.46-54
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• 2011

There have been research and developments for effective and efficient logistics and progress management in a construction project. Among them, RFID+4D has been developed for the supply chain management of long-lead item materials such as steel component, precast concrete component and curtain wall by integrating RFID with 4D CAD. And the feasibility of RFID+4D has been verified and validated and the benefits in terms of time and cost were shown in several case studies. However, the previous development of RFID+4D has not been adapted widely because of additional modeling cost, non-real time data update, additional labor for data update, and so forth. Therefore, this research has proposed a framework and process for solving these problems. And the web based simulation system has been developed and verified based on the proposed framework. The proposed framework and process can improve the existing RFID+4D system in a construction project by saving its operation cost and utilizing project information more efficiently and effectively. Also it is expected that the proposed framework could be applied to a method transferring design RIM data to construction BIM data.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.7-13
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• 2011

RAMS is the procedure to maximize the reliability and availability of systems with managing operation rate, the frequency of failure in the system and repair method. Recently, all system life-cycle focusing on RAMS process has been rapidly developing in the field of railway vehicles, for example, applying th reliability management techniques for procurement and disposal of EMU. In particular, global economic recession require to reasonable measures for the EMU maintenance costs under the circumstances therefore, an alternative solution based on RCM(Reliability Centered Maintenance) which is the optimal maintenance method is interested. In this study, the state of being critical of each component and a primary factors was analyzed to improve VVVF inverter of the line 7 EMU by applying FMECA process. Furthermore, this paper showed the impact of connecting between the main and sub system. Based on these data, critical components according to malfunction ratings were classified by screening measures and improvements for each components was summarized.

• Ocean Systems Engineering
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• v.2 no.2
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• pp.83-97
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• 2012

In the present work, design procedure and computer simulation of an AUV are documented briefly. The design procedure containing the design of propulsion system and CFD simulation of hydrodynamics behavior of the hull leads to achieve an optimum mechanical performance of AUV system. After designing, a comprehensive one dimensional model including motor, propeller, and AUV hull behavior simulates the whole dynamics of AUV system. In this design, to select the optimum AUV hull, several noses and tails are examined by CFD tools and the brushless motor is selected based on the first order model of DC electrical motor. By calculating thrust and velocity in functional point, OpenProp as a tool to select the optimum propeller is applied and the characteristics of appropriate propeller are determined. Finally, a computer program is developed to simulate the interaction between different components of AUV. The simulation leads to determine the initial acceleration, final velocity, and angular velocity of electrical motor and propeller. Results show the final AUV performance point is in the maximum efficiency regions of DC electrical motor and propeller.

• The Journal of Korean Association of Computer Education
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• v.6 no.3
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• pp.65-73
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• 2003

Most web-based learning is furnishing single side and consistent training resource to learner. Research was gone to apply item analysis method or to introduce web-based learning system using studying pattern. But, we need complicated algorithm or parameter setting etc, for apply these method. Therefore, in this research, we design and implement an item selection system in consideration of learner's incorrectness rate and problem frequency selection rate about question of item selection attribute. Also, as that embody business logic about item selection by EJB, efficient system development is available and we improved maintenance and reusability.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.153-158
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• 1997

This paper describes a formal safety analysis technique which is demonstrated by performing empirical formal safety analysis with the case study of beamline hutch door Interlock system that is developed by using PLC(Programmable Logic Controller) systems at the Pohang Accelerator Laboratory. In order to perform formal safety analysis, we have built the Z formal specifications representation from user requirement written in ambiguous natural language and target PLC ladder logic, respectively. We have also studied the effective method to express typical PLC timer component by using specific Z formal notation which is supported by temporal history. We present a formal proof technique specifying and verifying that the hazardous states are not introduced into ladder logic in the PLC-based safety critical system.

• Genomics & Informatics
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• v.5 no.4
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• pp.194-195
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• 2007

We have constructed the Rice Genome Information Service System (RGISS), which is an information service system of the Oryza sativa L. ssp. japonica (rice) genome, using the released version of rice Build 3.0 pseudomolecules based on the Ensembl architecture. The nonredundant library, composed of 3,360 clones of BACs, PACs, and fosmids, was used to construct supercontigs. RGISS contains 50,717 annotated genes from GenBank, 56,161 predicted genes from FgeneSH, and information on 9,587 markers, which includes STS, SSR, and EST-based RFLP. The 20,180 ESTs sequenced by the Korea National Institute of Agricultural Biotechnology (NIAB) were aligned and mapped into 168,792 exons. By gene ontology analysis, the classified protein numbers in the rice genome were 6158, 4531, and 12,364 proteins, which were mapped to molecular function, cellular component, and biological process, respectively.

• International Journal of Safety
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• v.3 no.1
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• pp.38-46
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• 2004

This paper introduces the software life-cycle V&V (verification and validation) tasks for the KNICS (Korea nuclear instrumentation and control system) project. The objectives of the V&V tasks are mainly to develop a programmable logic controller (PLC) for safety critical instrumentation and control (I&C) systems, and then to apply the PLC to developing the prototype of an engineered safety features-component control system (ESF-CCS) in nuclear power plants. As preparative works for the software V&V, various kinds of software plans and V&V task procedures have been developed according to the software life-cycle management. A number of software V&V tools have been adopted or developed to efficiently support the V&V tasks. The V&V techniques employed in this work include a checklist-based review and inspection, a requirement traceability analysis, formal verification, and life-cycle based software testing.

• The KSFM Journal of Fluid Machinery
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• v.8 no.5 s.32
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• pp.13-21
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• 2005

This study aims to analyze operating performance of a micro gas turbine with the aid of detailed measurements of various system parameters. In addition to embedded measurements, parameters such as exhaust temperatures, engine inlet temperatures and fuel flow rates are measured. Variations in measured data and estimated performance parameters are analyzed. Those data are processed to calculate losses along the power transmission line and the net gas turbine performance (power and efficiency based on the gas turbine shaft end) is isolated from the overall system performance. A method to estimate characteristic parameters such as component efficiencies, based on the comparison between measured and predicted performance data, is suggested and exemplified for the full load condition.