• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.483-488
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• 1998

A pressure drop model for the PWR grids with and without mixing device is proposed at single phase based on the fluid mechanistic approach. Total pressure loss is expressed in additive way for form and frictional losses. The general friction factor correlations and form drag coefficients available in the open literatures are used to the model. As the results, the model shows better predictions than the existing ones for the non-mixing grids, and reasonable agreements with the available experimental data for mixing grids. Therefore it is concluded that the proposed model for pressure drop can provide sufficiently good approximation for grid optimization and design calculation in advanced grid development.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.1
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• pp.71-79
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• 2006

In Korea, most landslides occurred during the rainy season and had a shallow failure plane parallel to the slope. For these types of rainfall-induced failures, the most important factor triggering slope unstability is decrease in the matric suction of unsaturated soils with increasing saturation depth by rainfall infiltration. The saturation depth was readily estimated using modified Green-Ampt model proposed by Chu et al. (Chu Model) at present. But Chu Model involves some problems for application, because water-redistribution phenomena were not effected. So the modified Chu Model (MCGAM) which reflect water redistribution phono mens was developed. The results showed that the MCGAM had a better agreement with measured volumetric water contents than existing Chu Model.

• Environmental Engineering Research
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• v.11 no.4
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• pp.201-207
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• 2006

A simple empirical model with good quantitative prediction of inter-particle and intra-particle distance in a cake layer with respect to ionic strength was developed. The model is an inverse length scale with functions of interaction energy and hydrodynamic factor and it explains that the inter-particle and intra-particle distance in a cake is directly related to the effective size of particles. Particle compressibility with respect to ionic strength was also predicted by the model. The model corroborated very well with experimental results of polystyrene microsphere latex particles microfiltation in a dead end operation. From the results of the model, specific cake resistance could be controlled by the same variables affecting the height of particle energy barrier described by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.69
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• pp.107-119
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• 2001

In this paper, we propose a model of improvement of quality system level using system FMEA. The system FMEA is developed to a system analysis technique using the concepts of conventional FMEA. This is know what is important factor to manage the ISO 9000 Quality System. Therefore, it is used the system FMEA as the main method of the proposed model. The important factors of this model are internal quality audits, corrective and preventive action, customer claim review management review. This model is considered to be guideline for improvement of quality system level. We show the efficiency of the proposed model by means of a case study.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3004-3006
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• 2000

In this paper, we propose an optimal design method of Fuzzy-Neural Networks model with parallel structure for complex and nonlinear systems. The proposed model is consists of a multiple number of FNN connected in parallel. The proposed FNNs with parallel structure is based on Yamakawa's FNN and it uses simplified inference as fuzzy inference method and Error Back Propagation Algorithm as learning rules. We use a HCM clustering and GAs to identify the structure and the parameters of the proposed model. Also, a performance index with a weighting factor is presented to achieve a sound balance between approximation and generalization abilities of the model. To evaluate the performance of the proposed model. we use the time series data for gas furnace and the numerical data of nonlinear function.

• Journal of Construction Engineering and Project Management
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• v.7 no.3
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• pp.39-55
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• 2017

Preeminent performance of construction industry are unattainable with poor productivity resulting in time and cost over runs. Enhancement in productivity cannot be achieved without identifying and analyzing factors that adversely affect productivity. The objective therefore is to propose a productivity analysis model to quantify the probability of effect of factors influencing productivity by using fuzzy logic incorporated with relative importance index method, for various types of construction projects. To achieve this objective, a questionnaire survey was carried out targeting respondents of Indian construction industry, from four distinct projects, namely, residential, commercial, infrastructure and industrial projects. Based on questionnaire administered, the relative importance and ranks of factors demonstrated using relative importance index method. Probability assessment model to analyze productivity was then developed by using Fuzzy Logic Toolbox of MATLAB. The applicability of the proposed model was tested in seven construction projects and the probability of impact of factors on productivity evaluated. The results of application of model in the construction firms infers that the most contributing factor groups for most of the projects were discerned to be manpower, motivation and time group.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.864-869
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• 2004

In this paper, a blackbox approach is carried out to model the nonlinear dynamic bushing model. One-axis durability test is performed to describe the mechanical behavior of typical vehicle elastomeric components. The results of the tests are used to develop an empirical bushing model with an artificial neural network. The back propagation algorithm is used to obtain the weighting factor of the neural network. Since the output for a dynamic system depends on the histories of inputs and outputs, Narendra's algorithm of 'NARMAX' form is employed in the neural network bushing module. A numerical example is carried out to verify the developed bushing model.

• The Journal of Information Systems
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• v.19 no.2
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• pp.73-95
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• 2010

This study shows the scientific and systematic Evaluation Model using factor analysis and AHP methods for the success of defense Information System R&D projects. The evaluation model was divided into 7 evaluation factors such as Developing support, Developing infrastructure, Developing management and test & evaluation, Support factors for strength, Understanding & developing strategy, Developing technology & organization, and Developing performance. And those were composed of totally 24 low level Evaluation index. The Developed Evaluation Model in the paper could be contributed more to objectively and transparently company selection of defense Information System R&D and other defense R&D Projects in the future.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1234-1237
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• 1993

This paper discusses the hull form generation from fuzzy model constructed with actual ship data using fuzzy concept. SAC, which is the most important factor in the hull form generation, is expressed by a fuzzy model describing the relationships among design parameters, which have a great influence on SAC, through model identification process with the actual ship data and design parameters. Then, we can infer the SAC of an aimed ship through the process of fuzzy inference and decide the offset of a front view by making the fuzzy model between SAC and offset as well. In conclusion, this paper makes a step forward from the geometrical definition, which has been used for hull form generation so far, to direct mathematical formulae about the relationship between design parameters and offset. So, if the design parameters are given, we can generate the hull form taking such properties into account.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.73-78
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• 2003

In order to improve the safety performance oi construction projects, effective and corporative safety management program between head office and job site must be implemented. And its performance must be measured and analyzed for the identification of the problems in the safety management area. This study proposes a previous evaluation model of safety performance for the large construction firm in order to enhance their safety level. The fundamental data for proposed model is based on the past research(Son 2002), which is structured of evaluation criteria. weighted factor. statistical evaluation formula. The model would help the firm management in identifying the weak areas of safety performance in terms of the degree performing certain safety tasks. It is expected that the model could contribute to achieving the "zero accident" level.ot; level.