• International conference on construction engineering and project management
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• 2009.05a
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• pp.1100-1106
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• 2009

General contractors' overhead costs are increasing relative to direct costs. However, it is difficult to apply the traditional activity-based costing directly to the construction site overhead costing because the resource consumption rate per each activity is varied depending on the attributes of activities. The research develops a methodology of hybrid cost allocation system when resources are assigned to cost objects unlike the traditional activity-based costing. The study also develops a database program and demonstrates how it can be applied to the construction projects using a case study.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.841-844
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• 2005

Computer vision technology can be used to interpret the images captured by web cameras installed on construction sites to automatically quantify the results. This information can be used for quality control, productivity measurement and to direct construction. Steel frame construction is particularly well suited for automatic monitoring as all structural members can be viewed from a small number of camera locations, and three-dimensional computer models of steel structures are frequently available in a standard electronic format. A system is being developed that interprets the 3-D model and directs a camera to look for individual members as regular intervals to determine when each is in place and report the results. Results from a simple lab-scale system are presented along with preliminary full-scale development.

• Structural Engineering and Mechanics
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• v.12 no.6
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• pp.633-656
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• 2001

In this paper, modal control with direct output feedback is formulated in a systematic manner for easy implementation. Its application to the seismic protection of structural systems is verified by a shaking table test, which involves a full-scale building model and an active bracing system as the control device. Two modal control cases, namely, one full-state feedback and one direct output feedback control were tested and compared. The experimental result shows that in mitigating the seismic response of building structures, modal control with direct output feedback can be as effective and efficient as that with full-state feedback control. For practical concerns, the control performance of the proposed method in the presence of sensor noise and stiffness modeling error was also investigated. The numerical result shows that although the control force may be increased, the maximum floor displacements of the controlled structure are very insensitive to sensor noise and modeling error.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.155-156
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• 2021

Most of the construction works in domestic are not direct undertaking work, but by a contract method including subcontracting. Therefore, a general contractor for each project jointly carry out construction work with a specialty contractor for each engineering type. However, in terms of contract, this method is not a joint venture contract, but a subcontract. Accordingly, this system can cause various problems between the prime contractor and the subcontractor. Therefore, this study aims to extract and present the actual obstacle factors in terms of specialty contract company performing specialty construction work for construction project. The presented contents are expected to present the standard for the cooperation system that the prime contractor and the subcontractor can win-win.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2129_2131
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• 2009

Since Jan. 2004, the Ministry of Construction and Transportation has partly introduced estimation system of historical cost data in order to reflect result cost of construction market to cost estimation for public construction. It is expected that the purpose of the introduction would be evaluated considering the long-term development of domestic construction industry. In article 3, paragraph 4 of the planning criteria of estimated cost of financial regulation related to government contract rule, the profit estimated by historical cost data indicates sales profit and it is calculated by multiplying the sum of direct cost, indirect cost and general overhead by rate of profit. Finally, it is said that rate of profit cannot exceeds 10%. However, there are a lot of constructions for electronic equipment in the electronic construction and the proportion of government furnished material is very high, not like engineering works or constructions. Therefore, as the proportion of material cost over direct cost is relatively lower, if current rate of profit (10%) is applied, there would be a wide difference of cost in the items of profit under the estimation system of historical cost data. This paper was conducted to examine estimation methods of the items of profit under the estimation system of historical cost data and suggest reasonable applications.

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.155-159
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• 2007

Since Jan. 2004, the Ministry of Construction and Transportation has partly introduced estimation system of historical cost data in order to reflect result cost of construction market to cost estimation for public construction. It is expected that the purpose of the introduction would be evaluated considering the long-term development of domestic construction industry. In article 3, paragraph 4 of the planning criteria of estimated cost of financial regulation related to government contract rule, the profit estimated by historical cost data indicates sales profit and it is calculated by multiplying the sum of direct cost, indirect cost and general overhead by rate of profit. Finally, it is said that rate of profit cannot exceeds 10%. However, there are a lot of constructions for electronic equipment in the electronic construction and the proportion of government furnished material is very high, not like engineering works or constructions. Therefore, as the proportion of material cost over direct cost is relatively lower if current rate of exceeds (10%) is applied, there would be a wide difference of cost in the items of profit under the estimation system of historical cost data. This paper was conducted to examine estimation methods of the items of profit under the estimation system of historical cost data and suggest reasonable applications.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.653-657
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• 2007

Since the direct normal insolation is a main factor for designing any solar thermal power system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1990 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research's new data will be extensively used by solar thermal concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean 5.41kWh/$m^2$/day of the direct normal insolation was evaluated for clear day all over 16 areas in Korea. 2) Clear day's direct normal insolation of spring and summer were 5.54kWh/$m^2$/day and 5.86kWh/$m^2$/day, and for fall and winter their values were 5.32kWh/$m^2$/day and 4.92kWh/$m^2$/day respectively. So, spring and summer were higher, and fall and winter were lower than the yearly mean value.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.3
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• pp.273-279
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• 2004

This research is concerned with the development of an Internet-based robot system, which is insensitive to the unpredictable internet time delay. For this purpose, a simple mobile robot system that moves in response to the user s direct control on the internet has been developed. The time delay in data transmission is an important problem for the construction of this kind of system. Therefore, the PPS (Position Prediction Simulator) is suggested and implemented to compensate for the time delay problem of the internet. The simulation and experimental results show that the distance error can be reduced using the developed PPS.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.810-815
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• 2003

This research is concerned with the development of an Internet-based robot system, which is insensitive to the unpredictable Internet time delay. For that purpose, a simple mobile robot system that moves in response to the user' direct control on the Internet has been built. The time delay in data transmission is a big problem for the construction of this kind of system. Therefore, the PPS (Position Prediction Simulator) is suggested and implemented to compensate for the time delay problem of the Internet. The simulation and experimental result show that the distance error can be reduced using the developed PPS.

• Transactions of The Korea Fluid Power Systems Society
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• v.1 no.3
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• pp.14-19
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• 2004

The Direct Drive Valve used in this study contains a pressure-feedback-loop in itself, then it can eliminate nonlinearity such as the square-root-term in flow rate calculation and the change of bulk modulus of hydraulic oil. In this study, assuming that the dynamic characteristic of the DDV is modelled as a first order lag system, an parameter identification method using the input data and the output data is applied to obtain DDV's mathematical model. Then, a state feedback controller was designed to implement the force control of hydraulic system, and the control performance was evaluated.