• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.10
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• pp.1467-1477
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• 2002

This study was investigated physical properties of stretch fabrics by KES-FB system to show suitable basic data to making skirts of excellent capacity and develop more organized basic skirt pattern by fitness evaluation. 1. The results of T. H. V.(Total Hand Value) were as followa: In the kind of blending fiber, cotton/spandex was more excellent than nylon/spandex and polyester/spandex, in the direction of stretch, one-way(weft inserted polyurethan yarn) polyester/spandex and cotton/spandex were higher than two-way(warp and wet inserted polyurethan yarn) polyester/spandes and cotton/spandex, two-way nylon/spandex was higher than one-way nylon/spandex. 2. The results of calculating the variance between sample stretch fabrics and Japanese s/s women's suit fabrics after standardizing were as follows: Stretch fabrics has 2 range of tensile, bending, shearing, compression, surface, thickness and weight as compared with Jpanese s/s women's suit fabrics. In the tensile property, one-way stretch fabrics were almost the same with Japanese s/s women's suit fabrics, only two-way polyester/spandex had+1～+2 range. In the bending, shear property, there was no difference between sample fabrics and Japanese s/s women's suit fabrics 3. In the total fitness of the skirt, nylon/spandex is the best in the fabrics and one-way stretch fabric is better than two-way strethch fabric.

• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.11-19
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• 2015

Objective : The purpose of this study was to analyze the correlation between physical factors (X-factor, X-factor stretch) and club factors (club speed, ball speed, club path, smash factor, vertical launch angle, spin rate, flight time, total length) during impact and it affect on the total distance of the ball during a golf driver swing. Background : There were not enough studies that analyzed the correlation between physical factors(X-factor, X-factor stretch) and club factors(club speed, ball speed, club path, smash factor, launch angle, spin rate, flight time, total length) during a purpose swing to increase total distance. Method : For this study, 9 right handed professional male golfers (KPGA) were chosen. The test subject group used their own drivers and each took a total of 10 swings. These swings consisted of 5 purpose swings to increase total distance and 5 normal swings. Results : The purpose swing to increase total distance showed larger physical factors(X-factor, X-factor stretch) compared to a normal swing however the results were not statistically significant. Total distance increased during a purpose swing as a result of ball and club speed. Conclusion : The results showed that club factors, ball speed and club speed contributed the most in affecting the total distance of the ball during a purpose swing.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.6
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• pp.642-647
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• 2014

In this paper, a hybrid genetic algorithm (HGA) approach is proposed for an n-job, m-machine flow shop scheduling problem with limited capacity buffers with blocking in which the objective is to minimize the total stretch. The stretch of a job is the ratio of the amount of time the job spent before its completion to its processing time. HGA adopts the idea of seed selection and development in order to improve the exploitation and exploration power of genetic algorithms (GAs). Extensive computational experiments have been conducted to compare the performance of HGA with that of GA.

• Management Science and Financial Engineering
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• v.20 no.2
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• pp.33-37
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• 2014

A flow shop scheduling problem involves scheduling jobs on multiple machines in series in order to optimize a given criterion. The flow time of a job is the amount of time the job spent before its completion and the stretch of the job is the ratio of its flow time to its processing time. In this paper, a hybrid genetic algorithm (HGA) approach is proposed for minimizing the total stretch in flow shop scheduling. HGA adopts the idea of seed selection and development in order to reduce the chance of premature convergence that may cause the loss of search power. The performance of HGA is compared with that of genetic algorithms (GAs).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.187-192
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• 2014

Lot-streaming is the process of splitting a job (lot) into sublots to allow the overlapping of operations between successive machines in a multi-stage production system. A new genetic algorithm (NGA) is proposed for an n-job, m-machine, lot-streaming flow shop scheduling problem with equal-size sublots in which the objective is to minimize the total stretch. The stretch of a job is the ratio of the amount of time the job spent before its completion to its processing time. NGA replaces the selection and mating operators of genetic algorithms (GAs) by marriage and pregnancy operators and incorporates the idea of inter-chromosomal dominance and individuals' similarities. Extensive computational experiments for medium to large-scale lot-streaming flow-shop scheduling problems have been conducted to compare the performance of NGA with that of GA.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.273-284
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• 2007

The spatial and temporal zooplankton dynamics were examined along ca. 100-km section of the middle to lower Seomjin River (without estuary dam in river mouth) and Youngsan River (with estuary dam in river mouth) systems during study periods (2004. Nov.${\sim}$2006. Aug.) based on a monthly sampling intervals. The spatial variation of zooplankton biomass at both river ecosystems was distinct. There was considerable longitudinal variation in total zooplankton abundance in Youngsan R. stretch. The increase in total zooplankton abundance were observed along the longitudinal stretch toward the estuary dam. In contrast, there were not statistically significant longitudinal differences in total zooplankton abundance in Seomjin R. stretch. In Youngsan R. stretch, average abundance of total zooplankton (average ranges: $199{\sim}817$ Ind. $L^{-1}$ at 3 sampling sites, n=20) were nearly $4{\sim}60$ fold higher than that of Seomjin R. stretch (average ranges: $12{\sim}43$ Ind. $L^{-1}$ at 4 sampling sites, n=20). Relative abundance of rotifers (over 80% of total zooplankton abundance) at the whole sampling sites in Youngsan R. stretch were Much higher than that of the Seomjin R. stretch. The most abundant rotifers were Polyarthra spp., Brachionus spp., Colurella spp., and Keratella spp. at the both river ecosystems. In Seomjin R. stretch, copepods carbon biomass sharply increased toward in river mouth (over 40% of total zooplankton carbon biomass). Average ranges of total zooplankton filtering rates for phytoplankton at both river ecosystems varied from 21.2 to 92.9 mL $L^{-1}\;D^{-1}$ in Youngsan R. stretch and from 2.1 to 2.6 mL $L^{-1}\;D^{-1}$ in Seomjin R. stretch. Considering the zooplankton filtering rates, zooplankton as grazers of phytoplankton in Youngsan R. stretch seemed to play the more important role in planktonic food web than that of the Seomjin R. stretch.

• Archives of Orthopedic and Sports Physical Therapy
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• v.14 no.2
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• pp.91-97
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• 2018

Purpose: The purpose of this study was to observe the effects of sport massage and McKenzie stretch exercise on forward head posture. To understand the effect, this study measured and analyzed body alignment of the neck. Methods: In this study, a total of 14 subjects with forward head posture were analyzed. Subjects were divided into two groups: group 1 (n=7) received a McKenzie stretch exercise and group 2 (n=7) received a McKenzie stretch exercise and a sport massage. The McKenzie stretch exercise was performed three times a week, for four weeks, while the sport massage was performed once a week. The body alignment of the neck (CVA, CRA) was measured using a goniometer. Results: The improvements in neck body alignments (CVA, CRA) after the McKenzie stretch exercise and sport massage were both significant (group 1: p<0.05; group 2: p<0.05), whereas the between-group comparison found no significant differences. Conclusions: In conclusion, our study confirmed that the McKenzie stretch exercise and sport massage had a significant positive effect on the body alignment of the neck. However, a study that included a greater number of subjects and a long-term treatment period is needed to generalize these results.

• The Journal of Society for e-Business Studies
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• v.20 no.1
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• pp.79-88
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• 2015

Many servers, such as web and database servers, receive a continual stream of requests. The servers should schedule these requests to provide the best services to users. In this paper, a hybrid genetic algorithm is proposed for scheduling divisible requests without interruption in which the objective is to minimize the total stretch. The stretch of a request is the ratio of the amount of time the request spent in the system to its response time. The hybrid genetic algorithm adopts the idea of seed selection and development in order to improve the exploitation and exploration power of genetic algorithms. Extensive computational experiments have been conducted to compare the performance of the hybrid genetic algorithm with that of genetic algorithms.

• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.139-148
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• 2015

For design research of teenagers' posture correcting shirt, postures of teenagers were analyzed and became the base of inventing suitable patterns. The subjects of this study were 198 of both female and male middle school students from the city of Seoul. Students' postures in classroom and length change of body surface were observed and analyzed; based on this, total of 5 postures was selected, and length changes of body surface were applied. The patterns in this study were designed with stretch material to help antagonism by muscle movements. Each fabric that was used in this study had 110% of stretch, 120~140% of stretch, and 150~170% of stretch. Both of one-way-fabric and duplex-fabric were used in this study, depending on application site.

• Bulletin of the Korean Chemical Society
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• v.15 no.3
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• pp.228-236
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• 1994

The effect of the vibration mode coupling induced by the vibration-rotation interaction on total energy was investigated for the states with zero total angular momentum(J=0) in a quasilinear symmetric triatomic molecule of $AB_2$ type using a model potential function with a slight potential barrier to linearity. It is found that the coupling energy becomes larger for the levels of bend and asymmetric stretch modes and smaller for symmetric stretch mode as the excitation of the vibrational modes occurs. The results for the real molecule of $CH_2^+$, which is quasilinear, generally agree with the results for the model potential function in that common mode selective dependence of coupling energy is exhibited in both cases. The differences between the results for the model and real potential function in H-C-H system are analyzed and explained in terms of heavy mixing of the symmetric stretch and bend mode in excited vibrational states of the real molecule of $CH_2^+$. It is shown that the vibrational mode coupling in the potential energy function is primarily responsible for the broken nodal structure and chaotic behavior in highly excited levels of $CH_2^+$ for J= 0.