• Nuclear Engineering and Technology
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• v.28 no.3
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• pp.331-338
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• 1996

In the thermal-hydraulic design, the effect of fuel rod bow is quantified tv the rod bow DNBR penalty which is a key design parameter to assure the coolability of fuel assembly in the pressurized water reactor. In this work, a computer program for the evaluation of the rod bow DNBR penalty based on Westinghouse methodology is developed and its application procedure is proposed. The computer simulation is based on the Monte-Carlo method. The qualification of developed computer program is performed by a comparison of calculational result with that given by Westinghouse's document. A new application procedure is built using batch mean and batch standard deviation. The normality of sample population generated by the batch calculation is confirmed by means of a chi-square test for goodness of fit. On the view point of statistics it is effected that the more reliable design value may be produced by the new application procedure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.637-638
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• 2006

V-belt pulleys play a key role in driving cooling pump, oil pump, air-conditioner and so on by using an engine power. Precision deep drawing is one of the main processes for manufacturing the pulleys. Operation variables of the deep drawing equipment, called the setup parameter, must be re-determined whenever the specifications of pulley to be produced are changed. The defect rates during a setup of equipment and the working hours needed for the setup are almost dependent on workers' know-how. This study designs the program for easily determining setup conditions in pulley manufacturing process.

• Journal of Aerospace System Engineering
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• v.7 no.2
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• pp.8-14
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• 2013

When launch vehicles are manufactured, one of the key points is a design of lightweight structure for reducing costs. Isogrid structure was designed to solve this topic, and many researches were carried out about buckling load because compression load is mainly applied to them. Recently, many studies are also being carried out about FEM model geometry of isogrid structure. The reason is that isogrid structure depends on size of ribs so it is difficult to modify about small changes in rib pattern. In this study, 1/8 model of cylindrical isogrid structure model was developed to analyze buckling behavior. Through parameter study, buckling analysis were performed to analyze buckling load and buckling mode depending on size of ribs.

• Structural Engineering and Mechanics
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• v.82 no.1
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• pp.1-16
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• 2022

This work elaborately investigates the influences of the guideway geometry parameters and track irregularity on the dynamic performances of the suspended monorail vehicle-guideway system (SMVGS). Firstly, a spatial dynamic analysis model of the SMVGS is established by adopting ANSYS parameter design language. Then, the dynamic interaction between a vehicle with maximum design load and guideway is investigated by numerical simulation and field tests, revealing the vehicle-guideway dynamic features. Subsequently, the influences of the guideway geometry parameters and track irregularity on the dynamic performances of the SMVGS are analyzed and discussed in detail, and the reasonable ranges of several key geometry parameters of the guideway are also obtained. Results show that the vehicle-guideway dynamic responses change nonlinearly with an increase of the guideway span, and especially the guideway dynamic performances can be effectively improved by reducing the guideway span; based on a comprehensive consideration of all performance indices of the SMVGS, the deflection-span ratio of the suspended monorail guideway is finally recommended to be 1/1054~1/868. The train load could cause a large bending deformation of the pier, which would intensify the car-body lateral displacement and decrease the vehicle riding comfort; to well limit the bending deformation of the pier, its cross-section dimension is suggested to be more than 0.8 m×0.8 m. The addition of the track irregularity amplitude has small influences on the displacements and stress of the guideway; however, it would significantly increase the vehicle-guideway vibrations and rate of load reduction of the driving tyre.

• Journal of Computational Design and Engineering
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• v.3 no.4
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• pp.349-362
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• 2016

The numerical solutions of unsteady hydromagnetic natural convection Couette flow of a viscous, incompressible and electrically conducting fluid between the two vertical parallel plates in the presence of thermal radiation, thermal diffusion and diffusion thermo are obtained here. The fundamental dimensionless governing coupled linear partial differential equations for impulsive movement and uniformly accelerated movement of the plate were solved by an efficient Finite Element Method. Computations were performed for a wide range of the governing flow parameters, viz., Thermal diffusion (Soret) and Diffusion thermo (Dufour) parameters, Magnetic field parameter, Prandtl number, Thermal radiation and Schmidt number. The effects of these flow parameters on the velocity (u), temperature (${\theta}$) and Concentration (${\phi}$) are shown graphically. Also the effects of these pertinent parameters on the skin-friction, the rate of heat and mass transfer are obtained and discussed numerically through tabular forms. These are in good agreement with earlier reported studies. Analysis indicates that the fluid velocity is an increasing function of Grashof numbers for heat and mass transfer, Soret and Dufour numbers whereas the Magnetic parameter, Thermal radiation parameter, Prandtl number and Schmidt number lead to reduction of the velocity profiles. Also, it is noticed that the rate of heat transfer coefficient and temperature profiles increase with decrease in the thermal radiation parameter and Prandtl number, whereas the reverse effect is observed with increase of Dufour number. Further, the concentration profiles increase with increase in the Soret number whereas reverse effect is seen by increasing the values of the Schmidt number.

• Structural Engineering and Mechanics
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• v.62 no.2
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• pp.209-224
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• 2017

Elevated water tanks are considered as important structures due to its post-earthquake requirements. Elevated water tank on reinforced concrete frame staging is widely used in India. Different response reduction factors depending on ductility of frame members are used in seismic design of frame staging. The study on appropriateness of response reduction factor for reinforced concrete tank staging is sparse in literature. In the present paper a systematic study on estimation of key components of response reduction factors is presented. By considering the various combinations of tank capacity, height of staging, seismic design level and design response reduction factors, forty-eight analytical models are developed and designed using relevant Indian codes. The minimum specified design cross section of column as per Indian code is found to be sufficient to accommodate the design steel. The strength factor and ductility factor are estimated using results of nonlinear static pushover analysis. It was observed that for seismic design category 'high' the strength factor has lesser contribution than ductility factor, whereas, opposite trend is observed for seismic design category 'low'. Further, the effects of staging height and tank capacity on strength and ductility factors for two different seismic design categories are studied. For both seismic design categories, the response reduction factors obtained from the nonlinear static analysis is higher than the code specified response reduction factors. The minimum dimension restriction of column is observed as key parameter in achieving the desired performance of the elevated water tank on frame staging.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.911-917
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• 2017

There are generally three folds when developing neural network classifiers. They are as follows: 1) discriminant function; 2) lots of parameters in the design of classifier; and 3) high dimensional training data. Along with this viewpoint, we propose space search optimized polynomial neural network classifier (PNNC) with the aid of data preprocessing technique and simultaneous tuning strategy, which is a balance optimization strategy used in the design of PNNC when running space search optimization. Unlike the conventional probabilistic neural network classifier, the proposed neural network classifier adopts two type of polynomials for developing discriminant functions. The overall optimization of PNNC is realized with the aid of so-called structure optimization and parameter optimization with the use of simultaneous tuning strategy. Space search optimization algorithm is considered as a optimize vehicle to help the implement both structure and parameter optimization in the construction of PNNC. Furthermore, principal component analysis and linear discriminate analysis are selected as the data preprocessing techniques for PNNC. Experimental results show that the proposed neural network classifier obtains better performance in comparison with some other well-known classifiers in terms of accuracy classification rate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.38-51
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• 2000

The study on the mechanical behavior of a spot-welded specimen is largely divided into the quasi-static overload failure analysis and the fatigue failure prediction. The main issue in an overload analysis is to examine the critical loads, thereby providing a generalized overload failure criterion. As the welding spot forms a singular geometry of an external crack type, fatigue failure of spot-welded specimens can be evaluated by means of a fracture parameter. In this study, we first present the limit loads of 4 representative types of single spot-welded specimens in terms of the base metal yield strength and specimen geometries. Recasting the load vs. fatigue life relationships experimentally, obtained here, we then predict the fatigue life of spot-weld specimens with a single parameter denoted the equivalent stress intensity factor. This crack driving parameter is demonstrated to successfully describe the effects of specimen geometry and loading type in a comprehensive manner. The suggested fatigue life formula for a single spot weld can play a key, role in the design and assessment of spot-welded panel structures, in that the fatigue strength of multi-spots is eventually determined by the fatigue strength of each single spot.

• Journal of Pharmaceutical Investigation
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• v.22 no.3
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• pp.65-76
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• 1992

The superoxide dismutase (SOD)-mimetic activities of copper complexes of a series of salicylic acid (SA) analogs were tested and compared to the activity of bovine erythrocyte SOD using ferricytochrome c reduction assay. Stability constants of copper complexes were measured potentiometrically using SCOGS2 program. In the presence of 10 g/l albumin, all the copper complexes lost their SOD mimetic activities. Multiple regression analysis was employed for the statistical comparisons between the SOD mimetic activity and their physicochemical properties. Correlation exists for the SOD mimetic activity and steric parameter $(E_s)$ and/or electronic parameter $({\Sigma}{\sigma})$ in xanthine/xanthine oxidase (XOD) system, demonstrating that E, plays a key role in SOD activity whereas ${\Sigma}{\sigma}$ influences it to a lesser extent. The protective effect of copper complexes against membrane damage was measured by counting D-glucose released frm $EG_s$. D-glucose and XOD were entrapped within $EG_s$ and acetaldehyde was used as a substrate for XOD. In this membrane model system using $EG_s$, hydrophobic parameter $({\Sigma}{\pi})$ is of most importance, producing parabolic equation while $E_s$, and ${\Sigma}{\sigma}$ appear to playa minor role in protection against D-glucose release. In summary, to design an efficient SOD mimetic, stability, steric factor, lipophilicity and redox potential should be considered.

• Journal of the Korean Society of Systems Engineering
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• v.8 no.1
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• pp.63-75
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• 2012

For the definition of development project, this paper proposes an integrated design model for the project 3P's(Products, Process, and People) architecture solutions balancing the originating requirements as well as the design targets of product, process, and IPDT. The model is suggested to develop the integrated design method with trade-off analysis and alternatives evaluation of products, processes, and IPDT using QFD.