• Journal of Bio-Environment Control
• /
• v.4 no.1
• /
• pp.1-8
• /
• 1995

One of the most destructive forces around greenhouses is wind. Wind loads can be obtained by multiplying velocity pressure by dimensionless wind force coefficient. Generally, wind force coefficients can be determined by wind tunnel experiments. The wind force coefficient distribution on a single - span arched greenhouse was estimated using experimental data and compared with reported values from various countries. The results obtained are as follows : 1. The coefficients obtained from this study agree with the values proposed by G. L. Nelson except about 0.5 of difference in the middle region of roof section. This discrepancy is mainly attributed to the dissimilarity of experimental conditions (or wind tunnel test such as Reynolds number, type of terrain, surface roughness of model, location of the lapping and measuring methods. 2. Considering that the wind force coefficients are varied along the height of a wall at wind direction perpendicular to wall, structural analysis using subdivided wind force coefficient distribution is more resonable for wall. 3. It is recommendable that wind force coefficient distribution on a roof should take more subdivision than the existing four equal divisions for more accurate structural design. 4. Structural design using wind forces close to real values is more advantageous in safety and expense.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.8 no.3
• /
• pp.17-25
• /
• 2006

We performed the objective sensibility evaluation on knitted fabrics by the following procedures: setting acrylic fabrics with knitted fabrics as basis, knitted five kinds of blended spun yarns and four kinds of twisted filament yams made by different twisting methods(the amount and direction of twist) then, measuring mechanical properties in the use Kawabata Evaluation System, obtaining hand values and total hand values. The results are as follows: First, A(F)/W acrylic/wool spun knits obtain high scores in bending, compressing, shear properties, MMD, and thickness among five kinds of acrylic-blended knit fabrics. A(S)/W acrylic/wool blended knit represented prominent values at compressing properties and thickness and so wool-blended yams demonstrated superior characters comparing other blended yarns. To contrast, acrylic/rayon blended knits showed low scores in bending properties, shear properties and thickness, so that it affects to total hand values. On the one hand, among the four kinds of acrylic filament knitted fabrics, they do not exhibit any notable dynamic differences such as tensile properties of knitted fabrics by the twist number and direction of filament yarns, bending, shear, compressing properties, weight and thickness except surface properties. Second, fabrics showed the most high score at FUKURAMI (fullness and softness) among the hand values. A(S)/W acrylic/wool blended knits obtaining the lowest values at SAHRI (crispness) outrank at total hand values, so that it was the predominant knitted fabric in objective sensibility evaluation. In total hand values, five kinds of acrylic blended knits got a higher score than four kinds of acrylic filament knits, and the amount and direction of twist did not influence on total hand values among the four kinds of acrylic filaments.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.6 no.3
• /
• pp.67-81
• /
• 2004

This research demonstrates clothing consumption values, fashion preferences of career women from the early 1920s to late 1930s. And having thorough understanding of values and preferences, allows us to establish marketing strategies for clothing companies. The main purpose of this study is (1) to formalize consumer group based upon the clothing consumption values, (2) to find for characteristics of consumer depending on classification of consumption value in clothing, (3) to understand the preferences of career women about fashion trends. Analyzing data was performed 292 copies, resulting factor analysis, Cluster analysis, X-test, Anova, Tukey test, t-test, frequency analysis, and reliability analysis. This paper showed 7 distinctive characteristics of career women about clothing consumption value. These characteristics can be listed as 1) value of brand image, 2) value of self-expression, 3) functional values, 4) epistemic values, 5) coordination values, 6) social values 7) psychological values. Importantly, brand image value became most significant aspects among 7 factors. Analyzing consumers based upon stated 7 factors, it was found that they are segregated into 4 groups; Self-expressive Group, Psychological Stability Group, Functional Group, Social Group. Secondly, for fashion trend preferences, self-expressive group, psychological stability group, and functional group favored Romantic Feminine Style respectively. Social Group showed preference in Nu-Basic'. The reason for such trend dealt with fabric materials and colors. Finally examining population statistics, younger generations showed more preferences in Nu-Basic', and consumers from ages of 26 to 28, 32 to 34 showed preferences in Romantic Feminine' regardless of their household income, clothing related expenditures, jobs, and education level. On the other hand, 'Modem Classic' was popular among college graduates and 'Paradise' was somewhat less popular among all ages except from ages of 32 to 34, consumers consumption 300,000Won to 400,000Won on clothing related expenditures. And 'Energy' seemed to attract more highly educated females, who had more than masters in degrees with over 300,000 to 400,000Won for clothing related expenditures.

• Journal of Engineering Education Research
• /
• v.6 no.1
• /
• pp.15-21
• /
• 2003

This paper reports the results of course restructuring employing design projects in an introductory mechanics of materials course at Pennsylvania State University. Unlike traditional lecture courses, students were encouraged to learn the rudiments of mechanical design and how materials standards, economics, manufacturing, environmental, legal (liability) and societal (safety) concerns relate to design. Through conducting collaborative design projects, the instructors helped students to acquire more advanced skills such as team-based decision making, integration and establishment of criteria, use of modern design theory, consideration of alternative solutions, and application of realistic constraints. In order to examine the impact of new course changes on students' learning, a survey was conducted in 1998 Fall semester. According to the results of survey analyses, students reported high values on this introductory mechanics of materials course. However, they did not give high values on the design projects. Rather, they preferred lecture sessions. Additionally, it was also found that students who earned higher grades from a prerequisite course(statics) showed lower values on the design projects. Implications for engineering educators and suggestions for future research studies were discussed.

• Proceedings of the IEEK Conference
• /
• 2000.11a
• /
• pp.157-160
• /
• 2000

In order to design a low complexity and high performance SOVA decoder for Turbo Codes, we need to analyze the decoding performance with respect to several important design parameters and find out optimal values for them. Thus, we use a scaling factor of soft output and a update depth as the parameters and analyze their effect on the BER performance of the SOVA decoder. finally, we shows the optimal values of them for maximum decoding performance of SOVA decoder for 3GPP complied Turbo codes.

• Korean Journal of Optics and Photonics
• /
• v.4 no.4
• /
• pp.381-389
• /
• 1993

A software to calculate diffraction OTF from lens design data was developed and its accuracy was verified. To verify the accuracy, MTF of a standard lens system for OTF measurement were calculated. The results were compared with calculated values by another commercial software and measured values. We found that they have good agreements with one another.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.8 no.6
• /
• pp.602-614
• /
• 2016

It is necessary to develop an efficient optimization technique to perform optimum designs which have given design spaces, discrete design values and several design goals. As optimization techniques, direct search method and stochastic search method are widely used in designing of ship structures. The merit of the direct search method is to search the optimum points rapidly by considering the search direction, step size and convergence limit. And the merit of the stochastic search method is to obtain the global optimum points well by spreading points randomly entire the design spaces. In this paper, Pareto Strategy (PS) multi-objective function method is developed by considering the search direction based on Pareto optimal points, the step size, the convergence limit and the random number generation. The success points between just before and current Pareto optimal points are considered. PS method can also apply to the single objective function problems, and can consider the discrete design variables such as plate thickness, longitudinal space, web height and web space. The optimum design results are compared with existing Random Search (RS) multi-objective function method and Evolutionary Strategy (ES) multi-objective function method by performing the optimum designs of double bottom structure and double hull tanker which have discrete design values. Its superiority and effectiveness are shown by comparing the optimum results with those of RS method and ES method.

• Archives of design research
• /
• v.14 no.2
• /
• pp.107-116
• /
• 2001

Nowadays, The market environment is not static, but dynamic, it therefore requires global competition for the competitive advantage of product design in global market across boundaries. So if companies do not thoroughly understand core values, needs of consumers, and do not properly meet them, they cannot get the competitive advantage in global market for consumers. Therefore, the goal of this research is to develop a new design process for global markets through developing the on-line research analysis program and data-base. For this study, the researchers established a research framework associated with values, benefits and design attributes and developed a Global Design Process program through empirical researches. This research program is a upgraded system adapted to the digital period drastically.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.10
• /
• pp.1621-1626
• /
• 2001

The structural optimization have been carried out in the continuous design space or in the discrete design space. Methods fur discrete variables such as genetic algorithms , are extremely expensive in computational cost. In this research, an iterative optimization algorithm using orthogonal arrays is developed for design in discrete space. An orthogonal array is selected on a discrete des inn space and levels are selected from candidate values. Matrix experiments with the orthogonal array are conducted. New results of matrix experiments are obtained with penalty functions leer constraints. A new design is determined from analysis of means(ANOM). An orthogonal array is defined around the new values and matrix experiments are conducted. The final optimum design is found from iterative process. The suggested algorithm has been applied to various problems such as truss and frame type structures. The results are compared with those from a genetic algorithm and discussed.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.2
• /
• pp.309-319
• /
• 2016

This paper presents a new recognition and classification method for power quality (PQ) disturbances on the basis of pattern linguistic values. This method solves the difficulty of recognizing disturbances rapidly and accurately by using fuzzy logic. This method uses classification disturbance patterns to define the linguistic values of fuzzy input variables and used the input variables of corresponding disturbance pattern to set membership functions. This method also sets the fuzzy rules by analyzing the distribution regularities of the input variable values. One characteristic of this method is that the linguistic values of fuzzy input variables and the setting of membership functions are not only related to the input variables but also to the character of classification disturbance and the classification results. Furthermore, the number of fuzzy rules is equal to the number of disturbance patterns. By using this method for disturbance classification, the membership function and design of fuzzy rules are directly related to the objective of classification, thus effectively reducing the complexity of the design process and yielding accurate classification results. The classification results of the simulation and measured data verify the feasibility and effectiveness of this method.