• Structural Engineering and Mechanics
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• v.19 no.1
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• pp.107-121
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• 2005

The suboptimal control rule is introduced in structural control implementation as an alternative over the optimal control because the optimal control may require large amount of processing time when applied to complex structural control problems. It is well known that any time delay in structural control implementation will cause un-synchronized application of the control forces, which not only reduce the effectiveness of an active control system, but also cause instability of the control system. The effect of time delay on the displacement and acceleration responses of building structures is studied when the suboptimal control rule is adopted. Two examples are given to show the effectiveness of the suboptimal control rule. It is shown through the examples that the present method is easy in implementation and high in efficiency and it can significantly reduce the time delay in structural control implementation without significant loss of performance.

• Nuclear Engineering and Technology
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• v.42 no.4
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• pp.460-467
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• 2010

In this study, the parameters of the feedwater control system (FWCS) of the OPR1000 type nuclear power plant (NPP) are optimized by response surface methodology (RSM) in order to acquire better level control performance from the FWCS. The objective of the optimization is to minimize the steam generator (SG) water level deviation from the reference level during transients. The objective functions for this optimization are relationships between the SG level deviation and the parameters of the FWCS. However, in this case of FWCS parameter optimization, the objective functions are not available in the form of analytic equations and the responses (the SG level at plant transients) to inputs (FWCS parameters) can be evaluated by computer simulations only. Classical optimization methods cannot be used because the objective function value cannot be calculated directely. Therefore, the simulation optimization methodology is used and the RSM is adopted as the simulation optimization algorithm. Objective functions are evaluated with several typical transients in NPPs using a system simulation computer code that has been utilized for the system performance analysis of actual NPPs. The results show that the optimized parameters have better SG level control performance. The degree of the SG level deviation from the reference level during transients is minimized and consequently the control performance of the FWCS is remarkably improved.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.540-549
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• 2024

Despite the acknowledged benefits by incorporating daylighting in the lighting system of office buildings to enhance energy efficiency and ensure occupants' well-being, a significant gap in understanding the integration of daylighting control system (DCS) with Building Information Modeling (BIM) exists, which can lead to improved energy efficiency and enhanced building design, specifically regarding the impact of daylight on occupant comfort. Previous studies have highlighted the potential of BIM to revolutionize both architectural design and building performance. However, an untapped potential of BIM in facilitating daylighting control in office areas is yet to be explored. The significance of this study lies in prioritizing occupants' well-being and enhancing building performance. This research identifies the feasibility of BIM-enabled DCS through a literature review from three perspectives: BIM-enabled DCS and daylight strategies, BIM-assisted façade system improvement, and user-centric daylight utilization within BIM platforms. As for results, a sensor network diagram illustrating network structure, data flow, and connections between devices of BIM enabled daylight control system for office buildings are established. Additionally, a BIM assisted daylight control strategy diagram is presented to outline user-centric control facilitated by BIM platform. In terms of contribution to the body of knowledge, this research will provide a comprehensive synthesis of existing literature in this domain. Additionally, this research could provide architects, DCS designers, and sustainable building professionals with potential advancements and inspirations to promote energy-efficient and user-centric building design in the future.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.731-736
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• 2001

In this thesis, the study on controlling of cracks of concrete box culvert in early ages is presented. The optimum construction method and economical analysis were proposed also through the experiment of the material and field test. As a result of the experiment of the material, using fly ash, CSA expansive agent and BELITE cement(type IV) showed good result in the control of cracks induced by heat of hydration and shrinkage. As a result of construction test analysis, the maintenance time of form system did not show a big difference in controlling of cracks. Control of distribution of reinforcement, spacing of expansion joint and use of BELITE cement showed big differences in the control of cracks in early ages. As a result of economical analysis, control of construction variables before construction can make it possible to reduce the repair expense.

• Journal of the Korea Safety Management & Science
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• v.7 no.1
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• pp.11-23
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• 2005

It is difficult to put it into practice in that it requires bearing too much burden to draw out the planning itself in a case of large construction work. Consequently in this paper we select evaluation criteria by construction progress, classify into several categories, and regard potential danger which often occurs, as a evaluation criterion. Further step is to allow workers or collaborated companies to express their expert opinions or experiences and to encourage quality and process control and autonomous safety control by applying PSM(Process Safety Management) method using AHP(Analytic Hierarchy Process) and to development of PSIM(Process Safety Information Management) evaluation method in the construction. The reason why PSIM method should be quantitative and substantial progress is because it contributes Korean constructing companies to enhancing their safety control ability and to taking an equal stance just like developed countries, thereby strengthening their competitive edges.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.605-616
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• 2020

The construction quality control of hull blocks is of great significance for shipbuilding. The total station device is predominantly employed in traditional applications, but suffers from long measurement time, high labor intensity and scarcity of data points. In this paper, the Terrestrial Laser Scanning (TLS) device is utilized to obtain an efficient and accurate comprehensive construction information of hull blocks. To address the registration problem which is the most important issue in comparing the measurement point cloud and the design model, an automatic registration approach is presented. Furthermore, to compare the data acquired by TLS device and sparse point sets obtained by total station device, a method for key point extraction is introduced. Experimental results indicate that the proposed approach is fast and accurate, and that applying TLS to control the construction quality of hull blocks is reliable and feasible.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.595-598
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• 2024

This study was conducted to establish a hydrogen pipe network integrated control platform architecture for integrated management of full cycle information and data using digital twin technology, which is widely used in general industry and construction industry. To this end, we present a hardware configuration diagram for platform operators and service delivery methods, and an architecture(functional configuration diagram) for the development of a hydrogen pipe network integrated control platform. The results of this study conducted through the above process are summarized as follows. First, to establish the platform basic structure, the platform hardware configuration diagrams for WEB server, WAS server, DB server, BIM file conversion server, storage, and backup were presented. Second, the architecture(functional configuration diagram) for the hydrogen pipe network platform, platform utilization interface, external system, hydrogen pipe network standard system, and BIM-based hydrogen pipe network digital twin construction was presented to secure consistent data and manage information standards for each construction stage.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.105-109
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• 2010

Nowadays, the construction of high-rise building is rapidly increasing. There are many cost-increasing factors to the management in the high-rise building construction. For large and complex projects like the high-rise building construction, the more systematic methods and tools are needed for cost control. It is important to identify major cost control items and to manage them for effective cost management in the high-rise building construction. This study proposes a method of identifying major cost-increasing factors in the high-rise building construction based on the Delphi method.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.190-195
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• 2009

With the growth of information and communication technologies adoption in construction projects, it could be anticipated that more property owners and construction firms will attempt to use electronic gears and gadgets for site monitoring or surveillance purposes. As the construction workers may be the major group of project team members being monitored, from managerial perspectives and for ethical reasons, it is essential to investigate their degree of acceptance on site monitoring systems. Indeed studies on office workplace monitoring suggest that a monitoring system could shape or control the behaviors of employees. With adequate refinements, their research models could be applicable in the construction industry. This paper presents a model for analyzing the antecedences that affect workers' acceptance level on electronic monitoring, and investigating if there is any behavioral change.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1017-1021
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• 2005

There is a need for effective tracking and control of material loading and delivery time especially during the finishing-work phases to eliminate the need for lay-down space on the site. Hence, it is essential to monitor the relevant information regarding material procurement in construction sites, and it is also the key factor for successful site control and the adoption of the Just-in-Time concept for high-rise building construction. The purpose of this study is to test RFID's readability in order to develop a finishing material monitoring system through the application of RFID technology.