• Journal of the Korea Society for Simulation
• /
• v.9 no.4
• /
• pp.25-40
• /
• 2000

The cost of simulation modeling, the expertise required, and the pains of starting a new each time are impediments to more wide spread adoption of simulation technology. In addition, one of the most critical problems in the field of computer simulation today is the lack of published models and physical objects within the World Wide Web (WWW) allowing such distribution. From the viewpoint of WWW as distributed model repositories, it can be assumed that very many simulation models exist on the web. This paper is based on the premise that WWW is a distributed repository. Design Pattern, web-oriented technology like Java and CORBA, which are especially to cope with distributed objects, are introduced and discussed in detail for integration of simulation model. In this paper an architecture of model integration is proposed, which presents the whole procedure of model integration and how the Internet technologies are connected in. The central focus of this research is on the technical realization of integrating simulation models as distributed objects

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.890-896
• /
• 2009

In past projects, the main goal has been to enhance efficiency by reducing cost and time. However, considering the current condition of safety management in many construction companies, it can be confirmed that safety management has not been a top priority for a long time. Current safety management, which is based on safety standards and rules, is very ineffective and only emphasizes management after an incident. As well, although fewer accidents occur compared to the past, because construction projects are increasingly large in scale and complex, these accidents tend to be more serious and involve greater monetary loss. Furthermore, as the severity of these accidents increases, so does the possibility of fatalities. Therefore, improving safety management is essential. This study proposes an effective program for safety management, focusing on the processes to connect studies and systems, and the basic techniques required for program development. To realize this program, technical tools are suggested, including systems such as BIM (Building Information Modeling); additionally, the coordination of other systems such as an RTLS, a server, and an alarm system is proposed.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.2
• /
• pp.264-268
• /
• 2016

Recently, various energy efficiency optimization activities are ongoing globally by integrating conventional grids with ICT (Information and Communication Technology). In this sense, various smart grid projects, which power suppliers and consumers exchange useful informations bilaterally in real time, have been being carried out. The electric vehicle diffusion program is one of the projects and it has been spotlighted because it could resolve green gas problem, fuel economy and tightening environmental regulations. In this paper, the economics of V2G system which consists of electric vehicles and the charging infrastructure is evaluated comparing electric vehicles for V2G with common electric vehicles. Additional benefits of V2G are analyzed in the viewpoint of load leveling, frequency regulation and operation reserve. To find this benefit, electricity sales is modeled mathematically considering depth of discharge, maximum capacity reduction, etc. Benefit and cost analysis methods with the modeling are proposed to decide whether the introduction of V2G systems. Additionally, the methods will contribute to derive the future production and the unit cost of electric vehicle and battery and to get the technical and economic analysis.

• Steel and Composite Structures
• /
• v.18 no.1
• /
• pp.51-69
• /
• 2015

In recent years, the use of fiber reinforced polymer composites has increased because of their unique features. They have been used widely in the aircraft and space industries, medical and sporting goods and automotive industries. Thanks to their beneficial and various advantages over traditional materials such as high strength, high rigidity, low weight, corrosion resistance, low maintenance cost, aesthetic appearance and easy demountable or moveable construction. In this paper, it is aimed to determine and compare the geometrically nonlinear static and dynamic analysis results of footbridges using steel and glass fiber reinforced polymer composite (GFRP) materials. For this purpose, Halgavor suspension footbridge is selected as numerical examples. The analyses are performed using three identical footbridges, first constructed from steel, second built only with GFRP material and third made of steel- GFRP material, under static and dynamic loadings using finite element method. In the finite element modeling and analyses, SAP2000 program is used. Geometric nonlinearities are taken into consideration in the analysis using P-Delta criterion. The numerical results have indicated that the responses of the three bridges are different and that the response values obtained for the GFRP composite bridge are quite less compared to the steel bridge. It is understood that GFRP material is more useful than the steel for the footbridges.

• Transactions of Materials Processing
• /
• v.32 no.3
• /
• pp.122-128
• /
• 2023

As electric vehicles (EV) have increasingly replaced the conventional vehicles with internal combustion engines (ICE), most of automotive makers are actively devoting to the technology development of EV parts. Accordingly, the manufacturing process for power source has been also shifting from engine/transmission to EV motor/reducer system. However, lack of experience in developing the EV motor still remains as a technical challenge. In this paper, we employed the forming simulation based on finite element modeling to solve this problem. In particular, in order to increase the accuracy of the forming simulation, we introduced the elastic-plastic constitutive model parameters for polymer-copper hybrid wire by investigating the individual strain-stress curves, and elastic modulus of polymer and copper. Then, the reliability of modeling procedure was confirmed by comparing the simulated results with experiments. Finally, the identified mechanical properties and finite element modeling were applied to a hairpin forming process, which involves multiple deformation paths such as bending, pressing, widening, and twisting. The proposed numerical approach can replace common experience or experiment based trials by reducing production time and cost in the future.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.6
• /
• pp.809-820
• /
• 2023

In contemporary society, there is a notable rise in single-person households, coupled with an increased demand for residential spaces, necessitating the exploration of suitable housing solutions. Modular architecture is gaining prominence as a method to deliver cost-effective and sustainable living spaces efficiently. This study introduces a method for optimizing the design and construction processes of modular building units through Building Information Modeling(BIM) technology. It involves an analysis of factors that enhance living quality and meet the housing needs of single-person households. Utilizing BIM, a resource-efficient and cost-efficient modular apartment unit has been developed. BIM facilitates the visualization and integration of architectural components, thereby reducing design errors and enhancing productivity. This research evaluates both the benefits and constraints of modular architecture. Modular constructions, when combined with BIM, emerge as a potent solution for housing challenges, enriching the quality and variety of residential options. Nevertheless, considerations such as technical prerequisites and financial implications are also discussed. The study showcases the potential and merits of utilizing BIM for designing apartment units tailored to single-person households, offering a viable approach to ameliorate their living conditions.

• Environmental and Resource Economics Review
• /
• v.30 no.1
• /
• pp.107-128
• /
• 2021

It has been recognized that implementing the marginal price mechanism to CBP is not acceptable due to the lack of revenue of the marginal generators. This study shows that it is not the problem of marginal price mechanism but the structural problems originated by the suspension of restructuring, the technical limits of RSC program and inaccuracy of the generation cost estimation method. This study explains the method to calculate the cost function in operating modes of the CC generators and proposes the modeling for the CC generators in RSC program. To implementing the cost function in operating modes could give an opportunity to change the price setting mechanism from average to marginal cost. The price setting mechanism based on the marginal cost will be one of the main points to provide the right price signals and to introduce a real-time and A/S markets to prepare the energy transition era.

• Computers and Concrete
• /
• v.14 no.1
• /
• pp.73-90
• /
• 2014

The traditional destructive tests in damage detection require high cost, long consuming time, repairing of damaged members, etc. In addition to these, powerful equipments with advanced technology have motivated development of global vibration based damage detection methods. These methods base on observation of the changes in the structural dynamic properties and updating finite element models. The existence, location, severity and effect on the structural behavior of the damages can be identified by using these methods. The main idea in these methods is to minimize the differences between analytical and experimental natural frequencies. In this study, an application of damage detection using model updating method was presented on a one storey reinforced concrete (RC) building model. The model was designed to be 1/2 scale of a real building. The measurements on the model were performed by using ten uni-axial seismic accelerometers which were placed to the floor level. The presented damage identification procedure mainly consists of five steps: initial finite element modeling, testing of the undamaged model, finite element model calibration, testing of the damaged model, and damage detection with model updating. The elasticity modulus was selected as variable parameter for model calibration, while the inertia moment of section was selected for model updating. The first three modes were taken into consideration. The possible damaged members were estimated by considering the change ratio in the inertia moment. It was concluded that the finite element model calibration was required for structures to later evaluations such as damage, fatigue, etc. The presented model updating based procedure was very effective and useful for RC structures in the damage identification.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.15 no.2 s.95
• /
• pp.148-155
• /
• 2005

As functional requirement of massive digital information storage devices are on a trend for the higher data transfer rate and lower cost, many different technical efforts are being tested and implemented in the industry. FDB(fluid dynamic bearing) is one of the major breakthroughs in rotor design in terms of TMR(track misregistration) budget. Although FDB analysis based on Reynolds' equation is well established and popularly being used for FDB design especially for the estimation of bearing stiffness, there are obvious limitations in the approach due to the inherent assumptions. A generalized analysis tool employing the full Navier-Stokes equation and the energy balance is to be beneficial for detailed FDB design. In this publication, an efficient geometry modeling method is presented that provides fully integrated inputs for general FVM/FDM(finite volume method/ finite difference method) codes. By virtue of the flexibility of the presented method, many different detailed FDB design and analysis are carried over with ease.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.30 no.3
• /
• pp.223-230
• /
• 2017

BIM(building information modeling) has been actively applied to construction industries and to maximize its application through the life cycle of structure, various relevant technologies have been proposed. In particular, 4D sequencing management and 5D cost-related management were introduced as an improved version of the design review and interface control by 3D information design. On the other hand, the virtual construction using virtual construction equipment can sophisticatedly handle capacity, dynamic movement, collision boundaries of actual construction machines but it still stays at a low level in a technical sense. In this study, simulation systems based on BIM involving virtual construction equipment have been developed; then it is applied to the actual construction project to evaluate the safety and efficiency of construction equipments. It was confirmed that the simulation systems can be utilized to construct virtual construction site by using an effective 3D library of construction equipment and can plays a key role to secure construction safety and economic feasibility. Specifically, the simulation system are very useful for decision making by construction managers to select the optimum equipment and construction method with a better understanding for safety and cost-saving.