• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.10a
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• pp.24-31
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• 1997

Recently, in Korea, demand for establishment of systematic risk assessment techniques for construction projects has increased, especially after the large construction failures occurred during construction such as New Haengju Bridge construction projects, subway construction projects, gas explosion accidents etc. Most of existing risk analysis modeling techniques such as Event Tree Analysis and Fault Tree Analysis may not be available for realistic risk assessment of construction projects because it is very complex and difficult to estimate occurrence frequency and failure probability precisely due to a lack of data related to the various risks inherent in construction projects like natural disasters, financial and economic risks, political risks, environmental risks as well as design and construction-related risks. Therefor the main objective of this paper is to suggest systematic probabilistic risk assessment model and demonstrate an approach for probabilistic risk assessment using advanced Event Tree Analysis introducing Fuzzy set theory concepts. It may be stated that the Fuzzy Event Tree AnaIysis may be very usefu1 for the systematic and rational risk assessment for real constructions problems because the approach is able to effectively deal with all the related construction risks in terms of the linguistic variables that incorporate systematically expert's experiences and subjective judgement.

• Structural Engineering and Mechanics
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• v.83 no.1
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• pp.123-134
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• 2022

The stability of cable-stayed bridges is an important factor considered during design. In recent years, the novel spatial diamond-shaped bridge pylon has shown its advantages in various aspects, including the static response and the stability performance with the development of cable-stayed bridge towards long-span and heavy-load. Based on the energy approach, this paper presents a practical calculation method of the completed state stability of a cable-stayed bridge with two spatial diamond-shaped pylons. In the analysis, the possible transverse buckling of the girder, the top pylon column, and the mid pylon columns are considered simultaneously. The total potential energy of the spatial diamond-shaped pylon cable-stayed bridge is calculated. And based on the principle of stationary potential energy, the transverse buckling coefficients and corresponding buckling modes are obtained. Furthermore, an example is calculated using the design parameters of the Changtai Yangtze River Bridge, a 1176 m cable-stayed bridge under construction in China, to verify the effectiveness and accuracy of the proposed method in practical engineering. The critical loads and the buckling modes derived by the proposed method are in good agreement with the results of the finite element method. Finally, cable-stayed bridges varying pylon and girder stiffness ratios and pylon geometric dimensions are calculated to discuss the applicability and advantages of the proposed method. And a further discussion on the degrees of the polynomial functions when assuming buckling modes are presented.

• Journal of the Korean Institute of Rural Architecture
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• v.16 no.1
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• pp.27-34
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• 2014

This study is to understand fallible point on the step of design, construction and management, and suggest an improvement measure for the convenience of elderly through the field survey. The field survey on convenience facilities for the disabled of Senior Welfare Center in Chung-Buk Area was performed on approach to main entrance, parking lot, main entrance area, entrance door, passage, stair, elevator and toilet. It was discussed that barrier free design should be considered of main user's group and use pattern. Consequently, important points requiring circumspection at the step of design and construction was suggested.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.448-451
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• 2008

This study is under doing to suggest application manual using assembling reference plane design & standard finish material basis upon material classification code as a tool of a linkage between building design and construction standarization in order to enlarge the applicability of house building material that is produced by the module plant. We can say the goal of building standardization intend not only the improvement of construction productibility but also guarantee of subsequent performance through automatization basis upon informationalization of building design. For a etabilishing of this condition, it is neccessary to link the standardization's result of material--design--construction field. According to this neccessity, we are going to suggest information factor that can make relative business manager easily approach to the standardization practical task.

• Structural Engineering and Mechanics
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• v.23 no.6
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• pp.675-689
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• 2006

In structural analysis of tall buildings the traditional primary loading analysis approach that assumes all the loads are simultaneously applied to the fully built structure has been shown to be unsuitable by many researches. The construction sequential analysis that reflects the fact of the level-by-level construction of tall buildings can provide more reliable results and has been used more and more. However, too much computational cost has prevented the construction sequential analysis from its application in CAD/CAE software for building structures, since such an approach needs to deal with systematic changing of resultant stiffness matrices following level-by-level construction. This paper firstly analyzes the characteristics of assembling and triangular factorization of the stiffness matrix in the finite element model of the construction sequential analysis, then presents a fast construction sequential analysis strategy and a corresponding step-by-step active column solver by means of improving the existing skyline solver. The new strategy avoids considerably repeated calculation by only working on the latest appended and modified part of resultant stiffness matrices in each construction level. Without any simplification, the strategy guarantees accuracy while efficiency is greatly enhanced. The numerical tests show that the proposed strategy can be implemented with high efficiency in practical engineering design.

• Structural Engineering and Mechanics
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• v.49 no.1
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• pp.65-80
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• 2014

This paper reports on the development of a minimum cost design model and its application for obtaining economic designs for reinforced High Strength Concrete (HSC) T-sections in bending under ultimate limit state conditions. Cost objective functions, behavior constraint including material nonlinearities of steel and HSC, conditions on strain compatibility in steel and concrete and geometric design variable constraints are derived and implemented within the Conjugate Gradient optimization algorithm. Particular attention is paid to problem formulation, solution behavior and economic considerations. A typical example problem is considered to illustrate the applicability of the minimum cost design model and solution methodology. Results are confronted to design solutions derived from conventional design office methods to evaluate the performance of the cost model and its sensitivity to a wide range of unit cost ratios of construction materials and various classes of HSC described in Eurocode2. It is shown, among others that optimal solutions achieved using the present approach can lead to substantial savings in the amount of construction materials to be used. In addition, the proposed approach is practically simple, reliable and computationally effective compared to standard design procedures used in current engineering practice.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1463-1467
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• 2009

Construction projects are vulnerable to diverse internal and external factors, requiring systematic and consistent performance management along the entire life cycle of a project. In particular, urban renewal projects have a range of performance measures, including policy reconciliation and permits, project development, project financing, design, construction, and occupancy and maintenance. This requires a program-level megaproject approach, which integrates each stage of a project as well as variety of stakeholders' interests in pursuing a project from different perspectives. However, previous research on performance management has focused especially on the limited scopes of factors, including cost, quality, and schedule at the project level or on financial factors at the firm level. Given the lack of current approaches, this study suggests an integrated and systematic performance management scheme to control urban renewal megaprojects at the broadened perspectives of the program level. To this end, this study adopts the balanced scorecard approach and elicits key performance indices associated with various project configurations. Finally, an algorithm is presented for quantitatively assessing the level of performances along whole life cycle of urban renewal megaprojects.

• Structural Engineering and Mechanics
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• v.16 no.3
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• pp.275-294
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• 2003

In this study, 24 high-strength concrete dapped-end beams were tested to study the effects of the amount of main dapped-end reinforcement, the nominal shear span-to-depth ratio, and the concrete strength on the shear strength of dapped-end beams. Test results indicate that the shear strength of dapped ends increases with the increase in the amount of main dapped-end reinforcement and the concrete strength. The shear strength of dapped-end beam increases with the decrease of nominal shear span-to-depth ratio. A simplified method for determining the shear strength of reinforced concrete dapped ends is also proposed in this paper. The shear strengths predicted by the proposed method and the approach of PCI Design Handbook are compared with test results. The comparison shows that the proposed method can more accurately predict the shear strength of reinforced concrete dapped-end beams than the approach of PCI Design Handbook.

• International Journal of High-Rise Buildings
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• v.13 no.1
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• pp.97-102
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• 2024

In this paper, we would like to share our ongoing research on global population and demographic shifts and the corresponding need for diverse responses. As population growth varies worldwide, the pressing issue is the current global housing shortage. The USA alone lacks 4 million homes, underlining the urgency for new construction and renewal of existing. Our focus is primarily on new building processes, which must also incorporate elements of renewal for future sustainability. Our research addresses several key questions: How will roles for construction professionals change? What should be the primary goal of the design process? What types of technologies are currently available, and which aspects of the process can be enhanced with AI? A significant part of our study is exploring sustainable building methods that reduce embodied carbon and increase speed of construction. Our goal is to extend the transition from smart homes to cities, analyzing the evolution towards smart communities and cities. A critical aspect of our research is the 'kit of parts concept, involving prefabrication and modular construction. This approach is essential for both rebuilding and new projects, potentially lowering costs in manufacturing and design for long term. Lastly, we present a detailed comparison of the construction industry with manufacturing.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.437-443
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• 2013

Recently, sustainable building design, a growing field within architectural design, has been emerged in the construction industry as the practice of designing, constructing, and operating facilities in such a manner that their environmental impact, which has become a great concern of construction professionals, can be minimized. A number of different green rating systems have been developed to help assess that a building project is designed and built using strategies intended to minimize or eliminate its impact on the environment. In the United States, the widely accepted national standards for sustainable building design are known as the LEED (Leadership in Energy and Environmental Design) Green Building Rating System. The assessment of sustainability using the LEED green rating system is a challenging and time-consuming work due to its complicated process. In effect, the LEED green rating system awards points for satisfying specified green building criteria into five major categories: sustainable sites, water efficiency, energy and atmosphere, materials and resources, and indoor environmental quality; and sustainability of a project is rated by accumulating scores (100 points maximum) from these five major categories. The sustainability rating process could be accelerated and facilitated by using computer technology such as BIM (Building Information Modeling), an innovative new approach to building design, engineering, and construction management that has been widely used in the construction industry. BIM is defined as a model-based technology linked with a database of project information, which can be accessed, manipulated, and retrieved for construction estimating, scheduling, project management, as well as sustainability rating. This paper will present a framework representing the building knowledge contained in the LEED green building criteria. The proposed building knowledge framework will be implemented into a BIM platform (e.g. Autodesk Revit Architecture) in which sustainability rating of a building design can be automatically performed. The development of the automated sustainability rating system and the results of its implementation will be discussed.