• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.17 no.6
• /
• pp.587-595
• /
• 2005

The heat and flow characteristics in a parallel-flow heat exchanger were examined numerically to obtain its optimal design variables. A desirability function approach was introduced to optimize its performance with respect to the design parameters over the design domain. By varying the importance of heat transfer and pressure drop which are out put variables, the optimal values of the design parameters are examined. As a result, the us-age of the desirability function is very effective for the optimization of the design variables in a heat exchanger since the changes of optimal values are physically appropriate by varying the importance of each output variable.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.1
• /
• pp.121-126
• /
• 2014

The accurate determination of induction motor efficiency depends on the estimation of the five losses of stator and rotor copper loss, iron loss, mechanical loss and stray load loss. As the mechanical and stray load losses are not calculated by electro-magnetic analysis, the values of these two losses are very important in induction motor design. In this paper, the values of mechanical loss and stray load loss are proposed through investigating testing data from commercial products of three phase induction motors under 37kW. If the values of this paper are applied to motor design, the accuracy of design and analysis can be improved. The losses of motors are obtained by using load and no-load test results following IEC 60034-2-1 standard.

• Proceeding of EDISON Challenge
• /
• 2016.03a
• /
• pp.469-472
• /
• 2016

Jansen Mechanism has been a constant popularity by researchers studying legged robots because of many benefits. This paper proposed the design process of optimized legged robots using Jansen Mechanism and m.Sketch(Jansen Mechanism simulation software). First, driving part of legged robots is designed in compliance with the design regulations of a competitive exhibition. Second, setting the length of link and position of joint is conducted in keeping with the constraints. Third, Ground Length (GL) and Ground Angle Coefficient(GAC) values are extracted by m.Sketch simulation. Finally, by repeating the previous procedures, comparing the GL and GAC values, find the optimum input values. This.

• Journal of Aerospace System Engineering
• /
• v.11 no.4
• /
• pp.1-7
• /
• 2017

The development of effective design allowable values for unmanned composite aircraft is an issue of paramount concern for the industry. The application of conventional manned aircraft structural certification methods to unmanned aircraft such as prototype and technology demonstrators, can lead to excessively long development time and costs. In this paper, the determining method of composite structure design allowable values for light composite unmanned aircraft is presented to reduce to the structural weight. This paper seeks to show the applicability of composite B-basis material values as a design allowable of light composite unmanned aircraft structures. A review of different civil and UAV targets failure probability is given. From the results, the researchers can know that the requirements of light composite unmanned aircraft design allowable should be alleviated, compared to manned composite aircrafts.

• International Journal of Highway Engineering
• /
• v.17 no.6
• /
• pp.33-36
• /
• 2015

PURPOSES : It is desirable for buses to be parallel to the face of the bus shelter at a bus stop. In this way, passengers can safely use the buses without moving into the vehicle area. The study was a review of the current bus bay geometric guidelines, to determine whether they lead buses to stop parallel to the face of the bus shelter by analyzing vehicle trajectory. METHODS : A commercial software program for vehicle trajectory analysis was used under our assumptions about bus dimensions and geometric values. The final position of the bus was analyzed for multiple trajectory simulations, reflecting various geometric alternatives. RESULTS : Within the scope of the study, we concluded that the current design guidelines need to be revised by the design values suggested by the study. CONCLUSIONS : The results of the study suggested alternative design values for bus bay geometry, based on the assumption that buses should be parallel to the face of the bus shelter in order to prevent passengers from moving into the vehicle area.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.50 no.6
• /
• pp.377-384
• /
• 2022

In the design of composite aircraft structures, it is very important to set material allowables and design values, which take into account certification. And when determining the material allowable and design value of composite structures, the static strength, damage tolerance requirements, and environmental effects should be considered. The building block approach has been applied to the civil and military aviation industry for a long time and provides the principal certification methodology. This current certification methodology is based on extensive testing including coupon, element, sub-component, and full scale test. In this paper, some examples of composite allowable tests have been presented and the fundamental background and application methods of the building block approach have been presented.

• Korean Institute of Interior Design Journal
• /
• v.21 no.3
• /
• pp.76-86
• /
• 2012

21st century has different characters from 20th century which was an era of machine and rationality based on the industrial revolution. With the advent of the digital revolution, it became an era of pluralism, culture, and emotion. The digital technology made it possible to connect the whole world together in real time and brought about the entirely new notion of time and space. It also dramatically altered the world view. Now we have a different set of social and cultural values from the past. This paper researched the influences of these social and cultural changes on public designs. The leading trends of public designs were analyzed and the successful cases were studied. The main research methodologies were the document review and the instrumental case study. The major social & cultural paradigms of a present era were classified as 'pluralism', 'digital & information revolution', 'human-centered value (against machine-centered value of 20th century)', and 'organic world view'. Each of the classified paradigms was analyzed more to find out the influences on the various trends of public designs. 'Pluralism' has influence on 'experiential public design', 'community art', and 'public design of local values'. 'Digital & information revolution' has influence on 'content-centered public design', 'smart public design', 'immaterial public design', and 'performance in public design'. 'Human-centered value' has influence on 'universal design approach in public design', and 'emotional public design'. 'Organic world view' has influence on 'sustainable public design', and 'ecological public design'.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.9
• /
• pp.1-8
• /
• 2020

In this study, the optimal design of the multi-cavity mold layout and packing pressure for the automobile TCU connector cover is determined based on the injection molding analysis and the desirability function method for multi-characteristic optimization. The design characteristics to be optimized are the warpage and sink marks of the product, the scrap of the feed system, and the clamping force. The optimal design is determined by performing injection molding analysis and desirability analysis for design alternatives defined by a complete combination of five mold layouts and six-level packing pressure. The optimal design shows that the desirability values for individual characteristics are quite high and balanced, and the resulting values of individual characteristics are satisfactorily low.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.572-577
• /
• 2007

The paper presents design optimization of an automobile body for dynamic stiffness improvement. The thicknesses of plates making-up the monocoque body of an automobile were employed as design variables for optimization and the objective was to increase the first torsional and bending natural frequencies. By allotting one design variable to each plate of the body, compared to previous works based on element-wise design variables, design space of optimization was reduced to a large extent and numerical instabilities such as checkerboard pattern was efficiently evaded. The method resulted to a considerable amount of increase in the automobile body's torsional and bending natural frequencies. Considering manufacturability of the optimized result, the converged values of plate thicknesses were approximated to commercially-available values by appropriately reflecting their design sensitivities.

• Journal of information and communication convergence engineering
• /
• v.13 no.3
• /
• pp.152-158
• /
• 2015

We consider the problem of designing independently operating local quantizers at nodes in distributed estimation systems, where many spatially distributed sensor nodes measure a parameter of interest, quantize these measurements, and send the quantized data to a fusion node, which conducts the parameter estimation. Motivated by the discussion that the estimation accuracy can be improved by using the quantized data with a high probability of occurrence, we propose an iterative algorithm with a simple design rule that produces quantizers by searching boundary values with an increased likelihood. We prove that this design rule generates a considerably reduced interval for finding the next boundary values, yielding a low design complexity. We demonstrate through extensive simulations that the proposed algorithm achieves a significant performance gain with respect to traditional quantizer designs. A comparison with the recently published novel algorithms further illustrates the benefit of the proposed technique in terms of performance and design complexity.