• Korean Journal of Applied Biomechanics
• /
• v.17 no.2
• /
• pp.145-156
• /
• 2007

The purposes of this study were to investigate kinematic parameters of racket head and upper extremities during squash back hand stroke and to provide quantitative data to the players. Five Korean elite male players were used as subjects in this study. To find out the swing motion of the players, the land-markers were attached to the segments of upper limb and 3-D motion analysis was performed. Orientation angles were also computed for angular movement of each segment. The results were as follows. 1) the average time of the back hand swing (downswing + follow-through) was 0.39s (0.24 s + 0.15 s). 2) for each event, the average racket velocity at impact was 11.17m/s and the velocity at the end of swing was 8.03m/s, which was the fastest swing speed after impact. Also, for each phase, 5.10m/s was found in down swing but 7.68m/s was found in follow-through. Racket swing speed was fastest after the impact but the swing speed was reduced in the follow-through phase. 3) in records of average of joints angle, shoulder angle was defined as the relative angle to the body. 1.04rad was found at end of back swing, 1.75rad at impact and it changes to 2.35 rad at the end of swing. Elbow angle was defined as the relative angle of forearm to upper arm. 1.73rad was found at top of backswing, 2.79rad at impact, and the angle was changed to 2.55rad at end of swing. Wrist angle was defined as the relative angle of hand to forearm. 2.48rad was found at top of backswing, 2.86rad at impact, and the angle changes to 1.96rad at end of swing. As a result, if the ball is to fly in the fastest speed, the body has to move in the order of trunk, shoulder, elbow and wrist (from proximal segment to distal segment). Thus, the flexibility of the wrist can be very important factor to increase ball speed as the last action of strong impact. In conclusion, the movement in order of the shoulder, elbow and the wrist decided the racket head speed and the standard deviations were increased as the motion was transferred from proximal to the distal segment due to the personal difference of swing arc. In particular, the use of wrist (snap) may change the output dramatically. Therefore, it was concluded that the flexible wrist movement in squash was very important factor to determine the direction and spin of the ball.

• Journal of the Korea Convergence Society
• /
• v.9 no.4
• /
• pp.285-301
• /
• 2018

The purpose of this study was to investigate the relationship between health-related physical fitness factors and cognitive function and isolation on 308 elderly over 65 years old in Seoul and Gyeonggi do. The measuring instrument were as follows demographic characteristics(age, education level, drink, spouse, participation on in exercise) and health-related physical fitness(grip strength, leg strength, flexibility, balance), cognitive function (MMSE-K, digit span test) and emotional/social aspects of loneliness and isolation was measured. As a results, first, depending on the degree of demographic characteristics of elderly had significant difference. Second, health-related physical fitness and cognitive function are positive correlated, negative correlation between cognitive function and isolation. Third, health-related physical fitness of the elderly had a significant effect on cognitive function. Fourth, health-related fitness of the elderly had a significant effect on isolation. Fifth, the cognitive function of the elderly had a significant effect on isolation. In conclusion, this study will provide basic data for future aged man welfare studies and contribute to extended studies.

• Polymer(Korea)
• /
• v.30 no.4
• /
• pp.338-349
• /
• 2006

Fully or nearly fully(8-cholesteryloxycarbonyl)heptanoated polysaccharide derivatives were synthesized by reacting cellulose, amylose, chitosan, chitin, alginic acid, pullulan or amylopectin with (8-cholesteryloxycarbonyl)heptanoyl chloride (CH8C), and their thermotropic liquid crystalline behaviors were investigated. Like in the case of CH8C, all the polysaccharide derivatives formed monotropic cholesteric phases with left-handed helicoidal structures whose optical pitches $({\lambda_m}'s)$ decrease with increasing temperature. Amylopectin derivative also formed a monotropic cholesteric phase with lefthanded helicoidal structures but, in contrast with the other derivatives, did not display reflection colors over the full cholesteric range, suggesting that the helicoidal twisting power of the cholesteryl group highly depends on the branched structure in amylopectin. The thermal stability and degree of order in the mesophase, the magnitude of ${\lambda}_m$ at the same temperature, and the temperature dependence of the ${\lambda}_m$ observed for polysaccharide derivatives were entirely different from those reported for the polymers in which the cholesteryl groups are attached to flexible or semiflexible backbones through flexible spacers. The results were discussed in terms of the difference in the chemical structures of the main and side chains and flexibility of the main chain.

• Polymer(Korea)
• /
• v.31 no.1
• /
• pp.58-67
• /
• 2007

Fully cholesteryloxycarbonated and (8-cholesteryloxycarbonyl) heptanoated disaccharide derivatives were synthesized by reacting cellobiose, maltose, and lactose with cholesteryl chloroformate or 8- cholesteryloxycarbonylheptanoyl chloride, and their thermotropic liquid crystalline properties were investigated. All the cholesteryloxycarbonated derivatives (CH1DSs) formed enantiotropic cholesteric phases, whereas all the (8-cholesteryloxycarbonyl) heptanoated derivatives (CH8DSs) exhibited monotropic cholesteric phases with left-handed helicoidal structures whose optical pitches (${\lambda}m's$) decrease with increasing temperature. All the CH1DSs, contrast with the CH8DSs, did not display reflection colors over the full cholesteric range, suggesting that the helicoidal twisting power of the cholesteryl group highly depends on the length of the spacer joining the cholesteryl group to the disaccharide chain. The thermal stability and degree of order in the mesophase and the temperature dependence of the ${\lambda}m$ observed for EH8DSs were entirely different from those reported for the cholesterol-bearing dimers and triplet and the (8-cholesteryloxycarbonyl) heptanoated polysaccharide derivatives. The results were discussed in terms of the difference in the number of the mesogenic units per mole of repeating unit and the flexibility of the main chain.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.6 no.1
• /
• pp.15-26
• /
• 2000

Purpose : This study was done to examine the actual effect of the scapular position in these flexibility tests. The purpose of this study was to examine the differences between the measurement of SRT(Sit-and-Reach Test) without intentional abduction of the scapular (pre-test) and with intentional abduction of the scapular (post-test). The hypothesis is: 1. There is no differences in the SRT result of the pre-test and the post-test. 2. There is no differences in the HJA(Hip Joint Angle) result of the pre-test and the post-test. 3. There is no differences in the Spine Motion Test(SMT) result of the pre-test and the post-test. Method : The total 60 people (30 men, 30 women) were participated in this study. In the pre-test, the subjects were asked to sit on the examination table and try the SRT motion; and then the HJA, SRT and the SMT numerical values were taken. In the post-test. the subjects were instructed to intentionally bring the scapula outward from the midline; and the HJA, SRT and the SMT numerical values were taken. Result : In the pre-test. the SRT result averaged 34.17cm. and in the post-test. the SRT result averaged 36.68cm. The difference was about 2.81cm which showed a significant mean statistically (p<0.01). The measurement increased by 8.22%. The HJA was $85.9^{\circ}$ in pre-test, and it was $85.5^{\circ}$ in post-test. giving the $0.4^{\circ}$ differences. Therefore, it didn't have a statistical mean (p>0.05). The SMT value was 69.56cm in the pre-test. and it was 69.28cm in the post-test, about 0.28cm decreased. Therefore, it didn't have a statistical mean (p>0.05). SRT values and HJA values were correlated (p<0.01). SMT values and SRT values (p<0.01), and SMT values and HJA values(p<0.05) were each in counter correlation. Conclusion : The result of the SRT without intentional scapular abduction (34.17cm) and with intentional scapular abduction (36.68cm) showed a significant increase about 8.22% (p<0.01). In SRT, the effect of the intentional scapular abduction on SMT showed no significant means, the pretest value being 69.56cm and the post-test value being 69.28cm (p>0.05).

• Journal of Fashion Business
• /
• v.11 no.5
• /
• pp.35-50
• /
• 2007

The purpose of this study was to investigate the result of a market research on men's jacket in their age of 25 to 35, who wear fitted jackets most, and to examine the comparative analysis of pattern and the wearing evaluation between classic jacket and fitted jacket. The results are as follows; Firstly, according to the results of a market research, 32.0% of the target owned fitted jackets, and 28.7% expressed their desire to buy only fitted jackets. This means their concern and preference for fitted jacket with which they could show up young, fresh and slim look are as high as those for classic jacket. Secondly, classic jacket showed the higher value than fitted jacket in such items as chest girth, waist girth, hip girth, sleeve's hem girth, jacket length, shoulder length, side seam length, and across shoulder point length. On the other hand, fitted jacket showed the higher value than classic jacket in back armhole length, front length, collar point length and sleeve's vent length. Thirdly, classic jacket was larger than fitted jacket in 1/2 chest girth(1.0cm), 1/2 waist girth(2.0cm), 1/2 hip girth(1.0cm), back width(0.5cm), front width(0.5cm) and side width(1.0cm). However, fitted jacket was higher than classic jacket in the armhole depth(0.5). Fourthly, the results of appearance evaluation revealed that there was a significant difference in 6 items. In other words, classic jacket was evaluated more appropriate than fitted jacket in such items as back width, back length, back neck depth, chest girth, waist girth and hip girth. And the fitted jacket had a higher value than the classic jacket in shoulder angle item. Fifthly, In the functional evaluation, fitted jacket was evaluated more uncomfortable than classic jacket. And this means that fitted jacket doesn't have a proper ease amount in each part and it has a high armhole depth compared to classic jacket. Therefore, for more comfortable patternmaking of fitted jackets, it would be required a pattern design which reflect men's own shoulder lines and women designers' flexibility that will satisfy both appearance and function.

• Journal of Korean Library and Information Science Society
• /
• v.8
• /
• pp.127-154
• /
• 1981

Today's complicated society with a rapid change needs more objective and accurate data for the better managerical decisions and the prospect for the future other than the intuition or subjective experience by men themselves. These data can't be extracted without the analysis of actual data by a n.0, pplying any of mathematical techniques. One of these mathematical techniques, called bibliometrics has been newly developed in the field of library and information science to extract the objective data for the better services through the library operations. The Beadford's Law, one important law in bibliometrics has provided rather scientific and objective basis on the more valid building of library collection within the constraints of budget. The purpose of the study is to investigate the theory of the Bradford's Law, to clarify the possible areas of its a n.0, pplication, and to discern some problems in doing so. The results of the study can be summarized as follows; (1) There is certain difference between the graphical formulation and verbal formulation of Bradford's Law. But this law is very useful for the field of library and information science, owing to the flexibility of the a n.0, pplication of the law in the field. (2) The minimal nucleus can consist of a single periodical only if j, the number of relevant papers in the most productive journals is greater than Z/2. On the other hand, if j is less than or equal to Z/2, then the minimal nucleus will consist of 2 or more periodicals. (3) It is possible to design the most compact selection of scientific periodicals covering any specified percentage P among the total periodicals by using the formulation, log n=Plog N+(1-P)logs, or Nlog N/s=P center dot N log N/s. (4) If there is need to provide all the articles needed by users the given budget, the library can purchase the proper number of journals, by using the formulation, f center dot AN=An+PN (log N/s-logn/s). (5) In the building of the library collection based on the decreasing ratio of use, the library can subscribe to the proper number of journals according to the satisfactory degree of the need, by using the formulation, f=Nu+uNlogN/S-uNlogn/s / nNlogN/s = 1+logN/m /logN/s (6) If the order of valuable journals is decided according to the frequency of being cited, the order can't always represent the value. (7) The evaluation criteria for the journals with high value, but less cited should be made a further study.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.5
• /
• pp.47-58
• /
• 2017

This study examined the effects of elderly people's frail prevention program performed in a senior center located in J-si. The most interesting were the effects on the subjective health status, depression, physical fitness, and quality of life for the senior center participation of the elderly. The nonequivalent control group pre-post-test design was employed. A total of 43 people living in J-si were assigned to either the experimental group (n=22) or control group (n=21). The experimental group was provided with the 8-weeks frail elderly prevention program from September 1 to October 16 in 2015. The data were analyzed with SPSS/WIN 21.0 using descriptive statistics, $x^2-test$, Fisher's exact test, and t-test. The results indicated a significant difference between the experimental group and control group with respect to the scores of the subjective health status (t=-0.35, p=.024), depression (t=2.76, p=.035), physical fitness, including right grip strength (t=-3.10, p=.004) and flexibility of the waist (t=-2.13, p=.039), and the quality of life (t=4.36, p<.001). In conclusion, an elderly people's frail prevention program has a significant effect on the change in subjective health status, depression physical fitness, quality of life, and self-care behavior for senior center participation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.26 no.6
• /
• pp.628-635
• /
• 2000

The purpose of this study was to evaluate the result after 2-phase surgical-orthodontic treatment without preoperative orthodontic treatment for the skeletal Cl III malocclusion patient and to obtain an adequate protocol on the bases of this result. This retrospective study of ten patients who underwent 2-phase treatment were done to evaluate 1) the surgical stability and relapse pattern 2) the facial esthetics 3) the TMJ problem 4) the total time of the treatment. Results were followed : 1) The horizontal relapse of the mandible was 26.8% and didn't show significant differences compared to the conventional 3-phase treatment. But, it was considered that this amount of relapse was the sum of true relapse and autoratation of mandible due to decreased vertical dimension during orthodontic treatment. 2) It was estimated that there's no difference on the ratio of anterior facial height between the subjects and the normal patients. On the horizontal analysis, the mandible of the subjects was located more anteriorly than that of the normal patients. This result showed that there was a need for the accurate preoperative esthetic evaluation and the additional methods for reducing the relapse due to the occlusal interference. 3) Wide variation was noted on the TMJ symptoms of the subjects, however, it was estimated that there's no significant differencees of symptoms compared to that of the conventional 3-phase treatment on literatures. 4) The average of the overall period of treatment was 20.8 months and we obtained reduction of the treatment time compaired to 3-phase treatment on many literatures. Most of the results of this study were similar to the findings of the 3-phase treatment(preoperative orthodontic-orthognathic surgery-postoperative orthodontic), but total time of the treatment was shorter in patients with 2-phase treatment than in those with the conventional 3-phase treatment. With 2-phase treatment, we experienced many advantages compared to the conventional method considering that it was favarable conditions for the teeth, it had the flexibility for the treatment, and it could be the adequate treatment approach for the stomatognathic system. Although this retrospective pilot study had some limitations, due to small samples, the authors would hope that it could serve as a guide for the future researches, and the clinical applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.56-56
• /
• 2010

Single-walled carbon nanotubes (SWCNTs) have attracted much attention as a promising material for transparent conducting films (TCFs), due to their superior electrical conductivity, high mechanical strength, and complete flexibility as well as their one-dimensional morphological features of extremely high length-to-diameter ratios. This study investigated three kinds of SWCNTs with different purities: as-produced SWCNTs (AP-SWCNTs), thermally purified SWCNTs (TH-SWCNTs), thermally and acid purified SWCNTs (TA-SWCNTs). The purity of each SWCNT sample was assessed by considering absorption peaks in the semiconducting ($S_{22}$) and metallic ($M_{11}$) tubes with UV-Vis NIR spectroscopy and a metal content with thermogravimetric analysis (TGA). The purity increased as proceeding the purification stages from the AP-SWCNTs through the thermal purification to the acid purification. The samples containing different contents of SWCNTs were dispersed in water using sodium dodecyl benzensulfate (SDBS). Aqueous suspensions of different purities of SWCNTs were prepared to have similar absorbances in UV-Vis absorption measurements so that one can make the TCFs possess similar optical transmittances irrespective of the SWCNT purity. Transparent conductive SWCNT networks were formed by spraying an SWCNT suspension onto a poly(ethyleneterephthalate) (PET) substrate. As expected, the TCFs fabricated with AP-SWCNTs showed very high sheet resistances. Interestingly, the TH-SWCNTs gave lower sheet resistances to the TFCs than the TA-SWCNTs although the latter was of higher purity in the SWCNT content than the former. The TA-SWCNTs would be shortened in length and be more bundled by the acid purification, relative to the TH-SWCNTs. For both purified (TH, TA) samples, the subsequent nitric acid ($HNO_3$) treatment greatly lowered the sheet resistances of the TCFs, but almost eliminated the difference of sheet resistances between them. This seems to be because the electrical conductivity increased not only due to further removal of surfactants but also due to p-type doping upon the acid treatment. The doping effect was likely to overwhelm the effect of surfactant removal. Although the nitric acid treatment resulted in the similar. electrical properties to the two samples, the TCFs of TH-SWCNTs showed much lower sheet resistances than those of the TA-SWCNTs prior to the acid treatment.