• Nuclear Engineering and Technology
• /
• v.55 no.5
• /
• pp.1791-1801
• /
• 2023

The multi-physics coupled methodologies that have been widely used to analyze the complex process occurring in nuclear reactors have also been used to the R&D of numerical reactors. The advancement in the field of computer technology has helped in the development of these methodologies. Herein, we report the integration of ADPRES code and RELAP5 code into the SALOME-ICoCo framework to form a multi-physics coupling platform. The platform exploits the supervisor architecture, serial mode, mesh one-to-one correspondence and explicit coupling methods during analysis, and the uncertainty analysis tool URANIE was used. The correctness of the platform was verified through the NEACRP-L-335 benchmark. The results obtained were in accordance with the reference values. The platform could be used to accurately determine the power peak. In addition, design margins could be gained post uncertainty analysis. The initial power, inlet coolant temperature and the mass flow of assembly property significantly influence reactor safety during the rod ejections accident (REA).

• International Journal of Aeronautical and Space Sciences
• /
• v.14 no.4
• /
• pp.297-309
• /
• 2013

Design optimization is a mathematical process to find an optimal solution through the use of formal optimization algorithms. Design plays a vital role in the engineering field; therefore, using design tools in education and research is becoming more and more important. Recently, numerical design optimization in fluid mechanics, which uses computational fluid dynamics (CFD), has numerous applications in the engineering field, because of the rapid development of high-performance computing resources. However, it is difficult to find design optimization software and contents for educational purposes in aerospace engineering. In the present study, we have developed an aerodynamic design framework specifically for an airfoil, based on the EDucation-research Integration through Simulation On the Net (EDISON) portal. The airfoil design framework is composed of three subparts: a geometry kernel, CFD flow analysis, and an optimization algorithm. Through a seamless interface among the subparts, an iterative design process is conducted. In addition, the CFD flow analysis and the design framework are provided through a web-based portal system, while the computation is taken care of by a supercomputing facility. In addition to the software development, educational contents are developed for lectures associated with design optimization in aerospace and mechanical engineering education programs. The software and content developed in this study is expected to be used as a tool for e-learning material, for education and research in universities.

• Journal of the Korean Society for Railway
• /
• v.10 no.2 s.39
• /
• pp.137-145
• /
• 2007

In traditional financial theory, the discount cash flow model(DCF or NPV) operates as the basic framework for most analyses. In doing valuation analysis, the conventional view is that the net present value(NPV) of a project is the measure of the present value of expected net cash flows. Thus, investing in a positive(negative) NPV project will increase(decrease) firm value. Recently, this framework has come under some fire for failing to consider the options of the managerial flexibilities. Real option valuation(ROV) considers the managerial flexibility to make ongoing decisions regarding the implementation of investment projects and the deployment of real assets. The appeal of the framework is natural given the high degree of uncertainty that firms face in their technology investment decisions. This paper suggests an algorithm for estimating volatility of logarithmic cash flow returns of real assets based on the Black-Sholes option pricing model, the binomial option pricing model, and the Monte Carlo simulation. This paper uses those models to obtain point estimates of real option value with the G7- HSR350X(high-speed train).

• Computers and Concrete
• /
• v.32 no.4
• /
• pp.399-410
• /
• 2023

This study proposes a novel use of backpropagated Levenberg-Marquardt neural networks based on computational intelligence heuristics to comprehend the examination of hybrid nanoparticles on the flow of dusty liquid via stretched cylinder. A two-phase model is employed in the present work to describe the fluid flow. The use of desulphated nanoparticles of silver and molybdenum suspended in water as base fluid. The mathematical model represented in terms of partial differential equations, Implementing similarity transformationsis model is converted to ordinary differential equations for the analysis . By adjusting the particle mass concentration and curvature parameter, a unique technique is utilized to generate a dataset for the proposed Levenberg-Marquardt neural networks in various nanoparticle circumstances on the flow of dusty liquid via stretched cylinder. The intelligent solver Levenberg-Marquardt neural networks is trained, tested and verified to identify the nanoparticles on the flow of dusty liquid solution for various situations. The Levenberg-Marquardt neural networks approach is applied for the solution of the hybrid nanoparticles on the flow of dusty liquid via stretched cylinder model. It is validated by comparison with the standard solution, regression analysis, histograms, and absolute error analysis. Strong agreement between proposed results and reference solutions as well as accuracy provide an evidence of the framework's validity.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.325-325
• /
• 2018

The main purpose of this study is to suggest the more reliable flow direction methods within the framework of DEM by investigating the existing methodologies. To this end SFD(single flow direction method), MFD(multiple flow direction method) and IFD(Infinite flow direction method) are applied to determination of flow direction for water particles in Jeonjeokbigyo basin, and then assessed with respect to the variation of flow accumulation. As the main results the different patterns of flow accumulation are found out from each application of flow direction methods. As the flow dispersion increases on DEM contributing areas to outlet grow in sequence of SFD, IFD, MFD but contribution of individual pixels into outlet decreases. Especially MFD and IFD tend to make additional hydrologic abstraction from rainfall excess due to the flow dispersion within flow paths on DEM. Based on parameter estimation for power law distribution by maximum likelihood flow accumulation can be thought of as scale invariance factor. Combination of several flow direction methods could give rise to the more realistic water flow on DEM through separate treatment of flow direction methods for dispersion and aggregation effects of water flow within different topographies.

• Journal of Korea Water Resources Association
• /
• v.40 no.12
• /
• pp.995-1005
• /
• 2007

This study presents a framework for optimum scale determination for small hydropower development in a river basin. The framework includes the construction of hydrology and topography data, the simulation of hydropower operation, the economic analysis, and the determination of optimum scale of the small hydropower. The optimum scale of design flow and facility are determined by Net Present Value among economic analysis indices. The investment cost is estimated by the cost function derived from the construction cost of existing small hydropower plants. The benefit from power generation is estimated by the price announced by government. The presented framework is applied to the two potential sites in Cho River basin for the dam and run-of-river type of plants. Finally, the sensitivity analysis for a design flow and scale of the plant is performed for the each site. The usage of the framework presented in the study is highly expected for the estimation of potential hydropower resources or the decision support tool for a proprietor by estimating the optimum scale and economical feasibility in advance.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.39 no.4
• /
• pp.325-333
• /
• 2015

This study was devoted to elucidating the change in the flow characteristics of a laminar flow past a circular cylinder by modifying the cylinder shape with O-grooves. A numerical analysis was performed in a two-dimensional framework. The cylinder was represented using an immersed boundary method and marker particles on a Cartesian grid system. The number and locations of the O-grooves were the key parameters. An analysis of the flow pattern and flow-induced forces was performed at Re = 40 and 50. In addition, we calculated the critical Reynolds number depending on the number of O-grooves and their locations.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.212-221
• /
• 2009

In this thesis, for analysis of efficient semantics flow frameworks with creative designing of interaction, we propose three elements: coincidence with intuition and common sense, self-leading activeness, and diversity of control parameters. Through analysis of my interactive art works, it is shown that the three proposed qualitative measures for interactive flow analysis are very useful evaluation measures for efficient semantics flows of interactive art works. In the experiments for this analysis, we measured the duration of each action-response feedback, the enjoyment duration of each entire art work, and the number of different types of interactions. The proposed qualitative measures can be used to design models for new interactive art works, as well as for the evaluating framework for existing art works.

• Journal of Distribution Science
• /
• v.20 no.2
• /
• pp.1-9
• /
• 2022

Purpose: The online distribution channel has attracted the attention of retailers by potential impact on consumers' purchase intention. The objectives of this study are to provide an insight into how to encourage consumers' impulse buying behavior on commercial website as well as attempts to reveal factors that influence consumers' impulsive buying behavior in the online shopping environment. Research design, data and methodology: The research framework is based on the stimulus-organism-response (S-O-R) framework. The Meta-analysis method carried out the research, gathering data from 37 published studies. Results: The research findings suggest that intrinsic motivations such as perceived ease of use, perceived enjoyment, and online flow experience play a significant role in boosting consumers' hedonic value when buying and online. In addition, these findings help online retailers use appropriate marketing stimuli such as offering pricing incentives, promotion tactics, and improved communication effectiveness. Also, obtaining a better grasp of how to build a website to improve the consumer experience generally helps consumers feel the urge to buy impulsively and act without hesitation. Conclusions: This research confirms a direct positive relationship between marketing stimuli and hedonic shopping value, which may support an applied theoretical framework for future research and provide managerial implications for retailers in online distribution channels.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1114-1117
• /
• 2004

Application of information technology for the construction area has been processed actively with the development of information technology. In this study, a framework of the Construction Specification IETM(Interactive Electronic Technical Manual) was suggested through the analysis of the Department of Defense(DoD)'s standards and the trend of techniques related to the IETM. As the Framework, the DFD(Data Flow Diagram) of the construction specification IETM's organizing and using procedure was suggested. And a Model of construction specification IETM was organized on the basis of DFD. Finally, a scenario was constructed by the pilot system which is based on the model. The application of the construction specification IETM would make efficient and effect task implementations possible. By that, in addition to the reduction of the cost and time, the quality enhancement from information missing protect effectiveness could be expected.