• Korean Journal of Construction Engineering and Management
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• v.10 no.1
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• pp.3-15
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• 2009

As building construction projects have been more higher and bigger in scale, the needs for cost reduction, productivity improvement, and reducing of work terms have rapidly increased in recent years. There has been, accordingly, a great emphasis on the necessity of logistics and progress management by well-organized system developed based on the appliance of different management theories. Although highly developed IT technology has contributed to the efficiency and effectiveness in information research and project management, RFID has been merely applied to a single progress or a few types of materials in current management studies, not to the overall process of the projects. This research proposes a consistent and systemized approach for decision making in adopting RFID technology in a construction project to support construction logistics and progress management. With a decision making model that consists of process model and template developed in this research, risks in cost, time, and error in building RFID-based construction logistics and progress management could be minimized.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.101-109
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• 2009

The people around industrial complexes and polluted areas suffer from the many occurrences of odors, and frequently issue a request for solving the odors to their local government in charge of those areas. Recently local governments whose regions have a number of such areas have a great interest in monitoring odor occurrences and gathering air on demand. This paper proposes a system in which a user can perform real-time monitoring the values of odor and atmospheric sensors, and the management of odor sensing devices using the Internet browser. Compared to previous systems, the system has an advantage of providing the functions for controlling and managing a number of devices irregardless of the location of the user. Also, the system is built around a blackboard-based multi-process architecture, enabling the easy incorporation of a new software model to be found useful. To our experiment, users showed great satisfactions in terms of the easiness of use. Our system has been installed and operated in an area of a local government in which odors are likely to occur.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.612-615
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• 2004

Today, the curtain wall is used in many construction projects because of excellent economical efficiency and constructability. The life-cycle process of curtain wall construction consists of the architectural design, curtain wall design, manufacturing, const겨ction, and maintenance phase which has become one of the most important objects that have to be managed. Since the general management method focused on each separated phase, it has accompanied many problems such as increases of the cost and duration, and loss of productivity. To solve these problems, it is necessa교 to have a new management method based on supply chain management. Thus this research analysed the processes of stick system, semi-unit system, unit system, and panel system classified by the type of the curtain wall, and suggested proper methods of application of SCM concept to each type of curtain wall construction.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.462-467
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• 2004

Design-build, which is defined as single source responsibility for design and construction, has been widely used in large public works since governmental formulation of measure for encouraging use of design-build in 1996. However, civic groups and small and medium sized enterprises are highlighting over-competition and unbalanced market shares of conglomerate in domestic design-bid market and insisting on decrease in the use of design-build and absorption into the lowest-price bidding. This study collected information about cost, schedule, quality, new technology adoption from 51 civil design-build projects and measured their performance.

• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.65-77
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• 2010

Our nation's housing construction is given much weight over 32% in 2007 and especially apartment is taking over 67%. If we put into construction environment consideration, we are having a trouble with price cap policy and the realestate recession due to the global economic crisis. So in order to get competitive power and supply of cheap apartment, the necessity of cost saving is increasing. This research collected the past constructed apartment project's cost saving examples which were influencing on the construction cost, quality and time. We analyzed collected cost saving datum and assorted these in compliance with classification system. By analysis of correlation among datum with exclusion and integration, we make a propose cost saving Checklist that will be a base data to give a chance to use in working level and other research.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.7
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• pp.20-28
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• 2002

In this paper, the aerodynamic performance prediction of a 30kW counter-rotating (C/R) wind turbine system has been made by using the momentum theory as well as the two-dimensional quasi-steady strip theory with special care on the wake and the post-stall effects. In order to take into account the wake effects in the performance analysis, the wind tunnel test data obtained for a scaled blade are used. Both the axial and rotational inductions behind the auxiliary rotors are determined through the wake model. In addition, the optimum chord and twist distributions along the blades are obtained from the Glauert's optimum actuator disk model considering the Prandtl's tip loss effect. The performance results of the counter-rotating wind turbine system are compared with those of the conventional single rotor system and demonstrated the effectiveness of the counter-rotating wind turbine system.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.1
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• pp.72-86
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• 2006

A technical review of current ramjet propulsion is presented. In addition to summarize the current status of ramjet technology, new key techniques like Boosting technique easily adapting total impulse of booster, flame stabilization technique with minimized ramjet combuster length, variable nozzle-inner-surface technique realizing wide flight-envelop, and thermal protection technique for long operating time are identified. Actually various Ramjet propulsion technology has been matured and expanding to both military and combined cycle application. Yet many opportunities remain to be challenged by future generations of explorers to utilize s typical ramjet propulsion system for multi-purpose(multi-platform and multi-target) missiles, for example, American JSSCM and Russian Yakhont missiles, improving both reliability of techniques and downsizing development cost of new propulsion system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.432-437
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• 2010

A new device injecting secondary fuel behind flameholder was invented and tested in order to reduce low frequency combustion instability of combustor using V-gutter flameholder. Specially designed combustion device could make large combustion instability up to 180 dB successfully, and newly invented device made a success to reduce 110~120Hz low frequency pressure pulsation up to 84%. It was found that the fuel flow rate of secondary fuel supplying behind flameholder was the only parameter which dominates reduction of instability. It is considered that stabilized flame with sufficient secondary fuel can lead to break the connection between combustion system and acoustic system due to independence of flame from fluctuation of main fuel resulted from synchronization with acoustic wave.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.2
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• pp.42-53
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• 2009

Gas turbine engine simulation program has been developed. In compressor and turbine, 2-D NS implicit code is used with k-$\omega$ SST turbulent model. In combustor, 0-D lumped method chemical equilibrium code is adopted under the limitations, the products are only 10 species of molecular and air-fuel is perfectly mixed state with 100% combustion efficiency at constant pressure. Fluid properties are shared on interfaces between engine components. The outlet conditions of compressor have been used as the inlet condition of combustor. The inlet condition of turbine comes from the compressor The back pressure in compressor outlet is transferred by the inlet pressure of turbine. Unsteady phenomena at rotor-stator in compressor and turbine is covered by mixing-plane method. The state of engine can be determined only by given inlet condition of compressor, outlet condition of turbine, equivalence ratio and rotating speed.

• Journal of Korean Society for Quality Management
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• v.50 no.4
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• pp.811-830
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• 2022

Purpose: In this paper, we will discuss 1) prioritizing databases to be integrated; 2) which data elements should be emphasized in federated database integration; and 3) the degree of efficiency in the integration. This paper aims to lay the groundwork for building data governance by presenting guidelines for database integration using metrics to identify and evaluate the capabilities of the UK's air quality databases. Methods: This paper intends to perform relative efficiency analysis using Data Envelope Analysis among the multi-criteria decision-making methods. In federated database integration, it is important to identify databases with high integration efficiency when prioritizing databases to be integrated. Results: The outcome of this paper aims not to present performance indicators for the implementation and evaluation of data governance, but rather to discuss what criteria should be used when performing 'federated integration'. Using Data Envelope Analysis in the process of implementing intelligent data governance, authors will establish and present practical strategies to discover databases with high integration efficiency. Conclusion: Through this study, it was possible to establish internal guidelines from an integrated point of view of data governance. The flexiblity of the federated database integration under the practice of the data governance, makes it possible to integrate databases quickly, easily, and effectively. By utilizing the guidelines presented in this study, authors anticipate that the process of integrating multiple databases, including the air quality databases, will evolve into the intelligent data governance based on the federated database integration when establishing the data governance practice in the railway industry.