• Journal of Ocean Engineering and Technology
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• v.24 no.4
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• pp.66-71
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• 2010

Numerical prediction of propeller performance plays an important role in a marine propeller design process. Program developers are consistently trying to improve diminish predicted errors, and program users need to keep up with the latest ones with minimum expenditure of time and money. We have developed an internet based design system in which clients can design propellers with remote access. In this paper, optimized Internet based Propeller Design and Analysis System (iProDAS) for transferences of the massive data is presented, and a sample design using iProDAS is examined.

• Steel and Composite Structures
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• v.42 no.1
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• pp.59-74
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• 2022

This study introduces a general reliability-based, performance-based design framework to design frames regarding their uncertainties and user-defined design goals. The Iterative-R method extracted from the main framework can designate a proper R (i.e., response modification factor) satisfying the design goal regarding target reliability index and pre-defined probability of collapse. The proposed methodology is based on FEMA P-695 and can be used for all systems that FEMA P-695 applies. To exemplify the method, multiple three-dimensional, four-story steel special moment-resisting frames are considered. Closed-form relationships are fitted between frames' responses and the modeling parameters. Those fits are used to construct limit state functions to apply reliability analysis methods for design safety assessment and the selection of proper R. The frameworks' unique feature is to consider arbitrarily defined probability density functions of frames' modeling parameters with an insignificant analysis burden. This characteristic enables the alteration in those parameters' distributions to meet the design goal. Furthermore, with sensitivity analysis, the most impactful parameters are identifiable for possible improvements to meet the design goal. In the studied examples, it is revealed that a proper R for frames with different levels of uncertainties could be significantly different from suggested values in design codes, alarming the importance of considering the stochastic behavior of elements' nonlinear behavior.

• Journal of the Korea Safety Management & Science
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• v.23 no.1
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• pp.57-64
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• 2021

Recently, advanced countries assessment the risk of fire to prevent large-scale damage to high-rise buildings, In addition, performance-Based design, which is a fire risk assessment, is being conducted in Korea to prevent massive damage to high-rise buildings. However, unlike advanced countries, fire risk assessment in Korea is subject to fire risk assessment only for objects subject to consent from fire-fighting facilities such as building permits, When building engineers and fire-fighting engineers assessment the risk of fire, It has always been discussed because the results vary depending on which part of the evaluation is focused between economic feasibility and safety. Therefore, in this study, we would like to propose a fire risk assessment process suitable for domestic conditions by comparing the process of performance-based design, which is a domestic fire risk assessment, and the process of Iso/TC 16732 which is an overseas fire risk assessment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.96-97
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• 2021

In the Building Act, performance-based fire safety design is being promoted for institutionalization. The behavior of the structure against fire conditions can be predicted by using the advanced numerical analysis method based on the FEM (Finite Element Method) to predict the entire structural behavior including the behavior of the structure, but there is a limit to expressing the fire properties of the space and predicting the fire properties It is difficult to determine the variables to be transmitted to the FEM (Finite Element Method) model from the fire simulation results using FDS (Fire Dynamics Simulator). Accordingly, the purpose of this study is to introduce the code user's manual for FDS and FEM unidirectional coupling analysis.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.10
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• pp.687-698
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• 2011

In this study, it was analyzed by a numerical analysis that plan/design considerations for ensuring the spectator safety of large arena audiences in a fire emergency evacuation plan. The latest issue, the 'performance-based design', fire and evacuation plan is important. But nowadays 'Specification-based design' is in common. In evacuation simulation, congestion of exit and aisle is ignored because only evacuation time of large-space is mainly analyzed. In smoke flow,'smoke filling effect' tends to be overrated. From now on, when design a field house, it is needed not 'smoke filling effect' and 'large-space evacuation' analysis, but analyzing 'whole building evacuation time' for ensuring fire evacuation safety of spectator.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.332-337
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• 2013

Various project delivery methods have been utilized by owners over the years to maximize project performance. The design-build delivery method is being increasingly used due to the advantages it can offer to an engineering construction industry. Numerous studies have advocated the use of design/build over the traditional design/bid/build delivery approach. This study represents comprehensive analysis of 40 projects from the construction industry and shows that design/build method may not provide all the benefits to project performance. This study found timesaving was a definitive advantage of design/build project delivery, but the positive effects of cost changes was not convincing. Based on the results of the study, the project management expertise and experience of the contractor may have a greater impact on project performance outcomes than focusing on project delivery strategy only.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.27-38
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• 2019

Sensors collect information for Internet of Things (IoT)-based services. However, indoor construction sites have a poor communication environment and many interfering elements that make it difficult to collect sensor information. In this study, a network was constructed between a Bluetooth Low Energy (BLE)-based IoT device based on a serverless IoT framework and a router. This experimental environment was applied to large- and small-scale indoor construction sites. Experiments were performed to test the communication performance of BLE-based IoT devices and routers at indoor construction sites. An analysis of the received signal strength indication (RSSI) graph patterns collected from the communication between the BLE-based IoT devices and routers for different testbed site situation revealed areas with good communication performance and poor communication performance due to interfering factors. The results confirmed that structural components of the building as well as the materials, equipment, and temporary facilities used in indoor construction interfere with the communication performance. Construction project managers will require improved technical knowledge of IoT, such as optimizing the router placement and matching communication between the router and workers, to improve the communication performance for large-scale indoor construction.

• Journal of the Korean Society of Systems Engineering
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• v.10 no.2
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• pp.59-69
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• 2014

In the bidding stage of turn-key based plant construction contracts, owners provide design and performance basis for contractors instead of giving design drawing. To win the bid for a plant construction, the contractors should be obliged to satisfy and ensure owners'requirements such as design and performance basis in a plant construction project, In other words, owners imposes technical risk of the design to the contractors by specifying responsibility for the analysis and verification of the plant construction. Thus, it is very important that contracters make accurate and realistic basic design plan in a short period of time. To deal with such a situation, we propose a systems engineering approach for the analysis and management of the technical risk. Specifically, we first: 1) Analyzes technical risk related with the plant design information for the bidders, followed by 2) Developing stakeholder requirements for the basic engineering design, and 3) System requirements for dealing with technical risk. Also, in this paper, we proposed converting method from MOE(Measure of Effectiveness) to MOP(Measure of Performance) in the risk analysis. To show the effectiveness of the proposed method, we carried out a case study.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.317-324
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• 2006

Performance-based design concept is needed to evaluate the seismic capacity of building. In this study, the method estimating the performance point of the spatial structures based on capacity spectrum method (CSM) is proposed. And for efficient evaluation for the performance point of the spatial structures, the algorithm to convert spatial structural system to ESDOF system is simulated Its efficiency is confirmed by comparing with time history analysis of full model. And dynamic behaviors of spatial structures are examined by using this method. At last, evaluation of structural performance according to variation of stiffness after plastic deformation on the substructures is carried out.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.477-478
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• 2010