• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.154-159
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• 2003

In this paper, the design improvement for high speed train carbody, which made by aluminium alloy, was described. The design improvements was achieved in fields of economical efficiency, extrusion, welding, assembling, etc. This paper also describes the result of carbody test. The purpose of the test is to evaluate an safety under the load and operation condition. This strength test based on KTX and reference code is UIC 566 and JIS E 7105. The test results shows that aluminium carbody structural have enough strength for all part.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.518-522
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• 2015

Green Construction is the construction activities that conserved energy, land, water and material to reduce the negative effect to the environment while assuring essential demand on quality and safety during project construction. This paper critically examine the contribution of awareness and understanding, green construction practices and green construction innovation with the green construction benefits. A measurement model based on the theoretical framework and exploratory factor analysis was developed and tested using structural equation modelling technique. This study employs a survey research methodology involving a total of 346 respondents among construction contractors, developers, clients and consultants in the construction industry. The findings indicate that the awareness and understanding, green construction practices and green construction innovation are significant predictors of the green construction benefits. From the practical perspective, the findings should alert the construction participants on the need of awareness and understanding, green construction practices and green construction innovation towards the green construction benefits. In addition, the findings can be used as diagnostic tool for continuous improvements in the Malaysian construction industry.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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• pp.433-440
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• 1998

For many decades, railroad technology was used to set up tracks with jointed rails and lengths in accordance with rolling and handling technology. The joints lead to drawbacks in the track and in controlling rising maintenance costs. So, railroad engineers became interested in eliminating joints to increase loads, speeds and improvements in rolling, welding, and fastening technology. Continuous welded rail(CWR) track has many advantages over the conventional jointed-rail track. In the case of the elimination of rail joints, it may cause the track to be suddenly and laterally buckled by thermal forces and vehicle load. Thermal forces are caused by an increase in the temperature of railway track. For many years, many analytical and experimental investigations have been conducted to improve the safety of CWR track by various research center in many country. In this paper, CWR track model and CWRB program is developed for buckling analysis using finite element method(FEM). The finite element discretization is used for a rail element with a total of 14 degrees of freedom. The stiffness of the fasteners, tie, and ballast bed is included by a set of spring elements. The investigation on the buckling modes and temperature of CWR track is presented in this paper

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.134-141
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• 2007

It is crucial that the WRMSD is realized as a critical job-related diseases for the construction workers. It is caused by the characteristics of repetitive work, uncomfortable work methods and continuous unsuitable physical posture. The objective of this research is to evaluate the workload for the carpenters and structural steel workers. Investigation on the posture and behavior for the workers as well as personal sensitivity to the workload is conducted. The laboratory tests with graduate students are conducted to estimate inconvenience in terms of personal sensitivity to the workload. The results of this research will be used to perform the further researches on ergonomic and technological approaches to improvements of the hand-intensive tasks in the construction industry.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.140-144
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• 2023

In recent years, there are so many serious crashes involving coaches, especially the frontal collision occupies 40% of the front of the vehicle, Frontal collisions account for 100% of the front of the vehicle affecting the driver and side-impact collisions that injure the person in the vehicle. Therefore, the research into improving and optimizing the structure is necessary for risk of injury for passengers in frontal accidents. In this paper, we have designed a Shock absorber that can absorb collision energy. Research using HYPERMESH software. to build the finite element model and calculate the meshing to suit the mesh size of 5mm. apply LS-DYNA software to calculate structural strength. In the study, for a vehicle to collide with a hard obstacle occupying 100% of the head of the vehicle. Then, the experimental design method, Minitab is used for find the structural parameters in the design. Improvement results showed that the acceleration of the impact on passengers and the driver is decreased by 55,17%. The mass of texture improvements is reduced by 11%, according to the requirements of European Standards ECE R94.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.643-652
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• 2007

This study identifies visible/invisible factors and analyzes facilities, structure, and visible perceptive contents in the aspects of operation and efficiency with a focus on the interfaces between interior design of the subway and users. More specifically, it diagnoses the requirements and empirically presents improvements. In addition, this study aims to diagnose the interfaces between trains and users by reinterpreting and evaluating factors from the perspectives of users, and to elicit the universal interface and an objective form of conceptual, structural, and formative relations in regard to the conditions required to the design. As the interior design in the subway trains is for the public reflecting the value, consciousness, and behaviors of users, it should be approached through the application of the concept of universal design that considers the potential needs and psychological satisfaction of users. In arranging the indoor of the vehicles, the conditions for the facilities should be specified through the interdisciplinary approach from professional fields including ergonomics and psychology, the path of flow should be induced through the use of space and the analysis of passengers' behaviors, an integrated planning should be re-established, and continuous evaluations of basic guidelines, manuals, and requirements should be made.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.261-272
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• 2013

LRT(Light Rail Transit), which has many merits compared with Heavy Rail Transit, is an effective public transport. Therefore, many local governments are pushing ahead with LRT. Busan had already adopted LRT(AGT)s like Busan Subway Line 4(Bansong Route) and Busan Gimhae Light Rail Transit(BGLRT) domestically for the first time. This study analyzes user satisfaction about the services of adopted LRTs and set right priorities of remeding their shortcomings from the user's perspective. In this paper, we surveyed safety consciousness and services satisfaction of LRT(BGLRT) users, and made two User Satisfaction Models of each LRT(BGLRT and Bansong Route) using Structural Equation Model. With established User Satisfaction Models(BGLRT Model and Bansong Route Model), we compared BGLRT and Bansong Route. Finally we found the measures and priorities for the improvements of LRT's services in the aspect of LRT users.

• Steel and Composite Structures
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• v.39 no.1
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• pp.81-93
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• 2021

Splitting tensile strength (STS) is an important mechanical parameter of concrete. This study offers novel methodologies for the early prediction of this parameter. Artificial neural network (ANN), which is a leading predictive method, is synthesized with two metaheuristic algorithms, namely atom search optimization (ASO) and equilibrium optimizer (EO) to achieve an optimal tuning of the weights and biases. The models are applied to data collected from the published literature. The sensitivity of the ASO and EO to the population size is first investigated, and then, proper configurations of the ASO-NN and EO-NN are compared to the conventional ANN. Evaluating the prediction results revealed the excellent efficiency of EO in optimizing the ANN. Accuracy improvements attained by this algorithm were 13.26 and 11.41% in terms of root mean square error and mean absolute error, respectively. Moreover, it raised the correlation from 0.89958 to 0.92722. This is while the results of the conventional ANN were slightly better than ASO-NN. The EO was also a faster optimizer than ASO. Based on these findings, the combination of the ANN and EO can be an efficient non-destructive tool for predicting the STS.

• Steel and Composite Structures
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• v.24 no.2
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• pp.227-237
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• 2017

This paper presents optimization of a long-span portal steel frame under dynamic wind loads using a surrogate-assisted evolutionary algorithm. Long-span portal steel frames are often used in low-rise industrial and commercial buildings. The structure needs be able to resist the wind loads, and at the same time it should be as light as possible in order to be cost-effective. In this work, numerical model of a portal steel frame is constructed using structural analysis program (SAP2000), with the web-heights at five locations of I-sections of the columns and rafters as the decision variables. In order to evaluate the performance of a given design under dynamic wind loading, the equivalent static wind load (ESWL) is obtained from a database of wind pressures measured in wind tunnel tests. A modified formulation of the problem compared to the one available in the literature is also presented, considering additional design constraints for practicality. Evolutionary algorithms (EA) are often used to solve such non-linear, black-box problems, but when each design evaluation is computationally expensive (e.g., in this case a SAP2000 simulation), the time taken for optimization using EAs becomes untenable. To overcome this challenge, we employ a surrogate-assisted evolutionary algorithm (SAEA) to expedite the convergence towards the optimum design. The presented SAEA uses multiple spatially distributed surrogate models to approximate the simulations more accurately in lieu of commonly used single global surrogate models. Through rigorous numerical experiments, improvements in results and time savings obtained using SAEA over EA are demonstrated.

• Journal of the Korean Society for Marine Environment & Energy
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• v.1 no.2
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• pp.82-95
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• 1998

In this paper, two series of numerical simulations are performed using LS/DYNA3D: The first series of numerical simulations are collision events between a 310,000 DWT double hull VLCC (struck ship) and two 35,000 and 105,000 DWT tankers (striking ships). Collisions are assumed to occur at the middle of the VLCC with the striking ships moving at right angle to the YLCC centerline. The second ones, grounding accidents of two 40,000 DWT Conventional and Advanced Double Hull lanker bottom structures, CONV/PD328 and ADH/PD328 models. The overall objective of this study is to understand the structural failure and energy absorbing mechanisms during collision and grounding events for double hull tanker side and bottom structures, which lead to the initiation of inner shell rupture and cause the kinetic energy dissipation to bring the ship to a stop. These numerical simulations will contribute to the estimation of damage extents of collision and grounding accidents and the future improvements in lanker safety at the design stage.