• Composites Research
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• v.12 no.6
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• pp.74-82
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• 1999

The static and fatigue characteristics of polyurethane foam cored sandwich structures are investigated. Three types of the specimens with the glass fabric faces and the polyurethane foam core are used; non-stitched. stitched, and stiffened sandwich specimen. Especially additional structural reinforcements with the twisted polyester and glass fiber for thickness direction are made to stitched sandwich structure panel to minimize the delamination of structure which is stitched the upper and lower faces through the core and the resin is impregnated Into stitched fiber with the characteristics of low viscosity of resin at resin flow temperature and cured together with during the curing process. Bending strength of stitched specimen which is 50 mm $50{\times}50{\;}mm$ pitched is improved by 50 % as com-pared with non-stitched specimen and stiffened specimen is improved 10 times more than non-stitched structure. After fatigue testing of $10^6$cycles by 20% of ultimate load under monotonic load, the bending fatigue strength of non-stitched specimen is decreased by 27% of monotonic bending strength, 39% for stitched structure and 20% for stiffened specimen. To verify the aging effect of polyurethane form core, Ultrasonic C-scanning equipment is used to detect the damage of skin laminate alone after fatigue test. From results of UT C-scan images, there is no defect that can be damaged occurred during fatigue test. It is concluded that the decrease of bending strength for foam cored sandwich specimen is caused by the decrease of stiffness due to the aging of polyurethane foam core during fatigue cycles.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.358-365
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• 2006

To study simultaneous water and solute transport kinetics during soaking in concentrated solution, the influence of the concentration and molecular weight of the solute(polyethylene glycol(PEG) and NaCl) in the soaking solution and the temperature on the water loss and solute gain rates were observed by using a model vegetable tissue(potato). When potato slices$(4cm{\times}4cm{\times}0.1cm)$ soaked in 60% PEG solutions, the water loss rate of the early phase decreased with increasing of the molecular weight of PEG from 200 to 6,000, while the final water loss increased with increasing the molecular weight of PEG and it reached to 80%. The cell wall of potato tissue was permeable to NaCl and PEGs of which average molecular weight is smaller than 400 but it was not permeable to PEG 600 and larger molecules. PEG which has average molecular weight below 600 induced plasmolysis and those above 600 induced cytorrhysis. The water loss rate of potato sample soaked in smaller molecular weight PEG solution was faster than those soaked in higher molecular weight PEG solution before cytorrhysis happened. The water loss rate was reversed after cytorrhysis happened. The volume change of potato within the first 60 minutes was larger in low molecular PEG solution but the final ratio of decreasing volume was larger in high molecular PEG solutions. In PEG 200 solution, the potato tissue was slightly shrinked without shape change. However, in PEG 4,000 solution, volume of potato was reduced significantly and potato tissue was twisted.

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.89-94
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• 2000

In order to induce the mutants of Gentiana axillariflora Leveille, nodes were cultured on Schenk and Hilderbrandt (SH) medium containing TDZ 2 mg/L, BAP 2mg/L, GA3 0.5 mg/L and 0.1 mg/L NAA and each mutagen of ethylmethanesulfate (EMS), colchicine, N-methyl-N-nitrosourea (MNU), and sodium azide (NaN$_3$) through filtration. Comparision of morphological characteristics and survival rate in each mutant plants differed depending on mutagen sources and their concentrations. When EMS were treated on nodes, the regenerated plants was thin and albino, regenerated shoots appeared 'erectoides type' and get twisted. The case of colchicine were treated on nodes, the survival rate was from 84% to 97% at ail concentration after 30days but the rate of survival was decreased about 50% at 200 $\mu$M after 60days. The treatment of NaN$_3$200 $\mu$M was not survived. The survival rate was extremely decreased in MNU treatment at 500$\mu$M, according to concentrations two types of leaf characteristic were obtained. Type I of leaf characteristic was modified from oblanceolate to oboid at leaf shape and type II of leaf characteristic was modified from light green to dark violet at leaf color. RAPD analysis was carried out to check the genetic modification of regenerated plants by mutagen treatments. Three polymorphic DNA fragments out of thirty-seven obtained by RAPDs were observed in regenerated plants using 5 decamer primers.

• The Research Journal of the Costume Culture
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• v.12 no.5
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• pp.859-879
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• 2004

As a result of research, the characteristics of the general costumes from the king Young-Cho period to the king Jung-Cho period in Genre Paintings of Mung-Hyun Oho, Yong Yun, In-Sang Lee, Hee-Eon Kang follows. First, the typical man wore his hair in a topknot(sangtu), and put on 'Bung-gu-ji', 'Lip', or a scarf on his head. The length of the 'Jeogori'(Korean traditional jacket) was long enough to cover the waist. Dress for work had side slits, and had half length sleeve Jeogori, and short pants looked like 'Jam-bang-i'. They went barefoot and wore 'Jipsin'(Korean traditional straw shoes). Dress for outdoor was 'Po' that knot at front of chest by band. 'Baji'(slacks) were with knot below knee, worn 'Hang-jun'(ankle band) and the width of slacks was suitable. They were 'Beoseon'(Korean traditional socks) and shoes. Second those in the upperc1ass and those in the military put on 'Mang-geon', 'Gat', 'Sa-bang-gan', 'Tang-geon', 'Bok-geon' on their head on a topknot. Most of them wore 'So-chang-i', 'Jung-chi-mag' or 'Do-po'. The length of Jeogori covered the waist or the hip and were tied with 'Go-rum'(ribbon). Baji was tied with Hang-jun and 'Dae-nim'. The waist of the slacks were tied with a dark colored waist-band and folded down their waist of slacks. They wore white color Beoseon and 'Hye' or dark color leather shoes. They wore 'Sup'(assistant of arm) for bow. It showed the lifestyle of the 18C with fan, 'Be-ru', 'Mug', 'Yun-jug', teacup, pot, etc. Third, child's hair was short or knotted to the back of the head. The length of Jeogori reached waist line, Git of Jeogori was 'Dunggurai-Kit'(shape of round) and other style Jeogori, which reached the hip line, had side-slit. Baji was tied with Dae-nim, and the width of the slacks is suitable. They hang 'Yum-nang'(Pocket). Final, most women worked outdoors wearing their hair in a high twisted style, or covered it with scarf. They wore Jeogori and 'Chima'(Korean traditional skirts), Bagi. They folded up the sleeves of the Jeogori. And they folded the 'Jambang-i-styled' pants to just above the knees, fastening at the waist. When they wore skirts, they also wore underpants under the skirt that went down to the knees. Most of them went barefoot and wore straw shoes, Jipsin. Through genre paintings, we can understand the ways and forms of our ancestor's clothing. And with our understanding, interest, and passion, we can be familiar with Hanbok in our daily life by succeeding and creating its peculiar style. And then we can promote the globalization of Hanbok.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.697-704
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• 2017

High-Performance Fiber-Reinforced Cement Composites (HPFRCC) has outstanding durability, and has attracted interest because of its ductility and development of strength, which allows a reduction of the self-weight of a structural member by substantially decreasing the cross section. Therefore, the present study aimed to improve the economic efficiency of HPFRCC by examining experimentally the flexural performance considering various characteristics of the steel fiber. To find an efficient fiber reinforcement method, the flexural performance was evaluated for different shapes, aspect ratios, and volume ratios of the steel fiber. Straight, hooked, and twisted fiber configurations were considered by adopting a fiber length longer than the usual 13 mm. The test results showed that HPFRCC reinforced by 19.5 nun-long straight fibers with a volume fraction of 1.5% shows better flexural performance than that reinforced by 13 mm-long straight fibers with a volume fraction of 2.0%. Consequently, HPFRCC with enhanced economic efficiency can be produced by adopting a reduced amount of steel fiber.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.1
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• pp.36-44
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• 2020

This study analyzed the Planting Prototype of Haengdan(杏壇)is the One of the traditional planting techniques and the value of natural monument plant and derived the value of the ginkgo tree in Sejong-ri as a natural monument. The results are as follows; First, ginkgo trees have high environmental adaptability, practicality and visual value. There were also many ginkgo trees that were deeply related to Confucian and Buddhist ideas. Ginkgo trees accounted for the largest portion of the number of old tree designated as natural monuments in recognition of their value. Second, after analyzing the historical and cultural values of ginkgo trees, ginkgo trees became the place of gardens and buildings by symbolizing Confucius(孔子)' Confucian ideas. In Buddhism, it was related to the creation of temples or the achievements of ancient monks. The people had a symbol of the prosperity of their offspring and the succession of the family. Third, in 1024 gongdobo, the grandson of Confucius, rebuilt the shrine, installed the platform in the central position and planted ginkgo trees. It originated from what he called "the "haengdan(杏壇)." The tree was then recorded as "heungheang(紅杏)" which was written by Wang Jae-jin's poetry during the Ming Dynasty. Thus it was misused as apricot tree. The cause of this is due to the same kanji reading. or it can be seen as influence on the taoism. But Korea has been sticking to the use of the first ginkgo trees. Forth, biologically, the Sejong-ri ginkgo tree is characterized by the composition of a pair of male trees. The landscape is contrasted with the twisted male tree and vertical female trees. In addition, in terms of authenticity and integrity, the relationship between Admiral Im, Nan-Su(林蘭秀) of the Goryeo Dynasty and the ginkgo tree is found in various literature.

• Korean Journal of Applied Biomechanics
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• v.16 no.1
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• pp.55-63
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• 2006

The purpose of this study is to prove the kinematical characteristics of Deff motion, the high bar performance, in terms of flying phases so that we can provide basic sources for improving gymnastic performance. To do this, we selected and analyzed the performance of two athletes who did Deff motion in the high bar competition of male artistic gymnastic in the 22nd Universiade 2003 Daegu. We drew the conclusions from the kinematical factors that were came out through analyzing three-dimensional cinematography of the athletes' movements, by using a high speed video camera. To make a successful performance, a performer releases the bar at a height of a high bar vertically and at a height of 82cm horizontally, and the flying performance should be made without moving forward, as maintaining the proper balance, in order to rise over 118cm high during the flying phase. When the performer is releasing the bar, an increase of the vertical speed in the center of the body and extension of a knee joint and a hip joint contribute to increasing a flying height. And when the moving body is twisted, leaning to left side is caused by the winding movement of a knee joint, which causes an unstable bar grasp. To grasp the bar stably, just before releasing the performer should gain propulsive force from twisting rotation through increasing the speed of shoulder rotation. And before the peak point, the performer should make sure of a body rotation distance over $164^{\circ}$ so that he or she can do an aerial rotary performance smoothly. When grasping the high bar, the center of the body should be above the bar and the angle of shoulder rotation should be maintained close to $540^{\circ}$ simultaneously. he high point performance(S1) has more speed on an ascending phase and less speed on a descending phase than the low point performance (S2). At the peak point, both the rotation angle of the body and that of the shoulder in high point performance are big as well. In conclusion, it is shown that a performer can make a jump toward the high bar easily with the body straight because the performer can hold the upper part of the body erect early in a descending phase.

• The Journal of the Korea Contents Association
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• v.12 no.6
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• pp.151-159
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• 2012

The purpose of this thesis is to figure out the mechanism that how can be shown the aesthetic distances of novel in the film. At discussion of the view point, novel can be told by two factors which are 'who is teller' and 'who is watcher' but in the film, novel's narration is divided into visual point and auditive point. And I will consider the phenomenon on the part of this difference. Next, I will argue about difference between novel and film from the Park Jongwon's aesthetic distances which interpreted Lee Munyeol's work. This thesis is going to observe that how the film adapted three types of view point and how that related the subject of the original novel. For this thesis, I tried to track 'the distances' between figure and identity, and reader and author. Also I did approach that how can be accepted the problem of 'aesthetic distance according to identity' based on this novel in the film and novel's text by reader. This study make a proposal or analysis to the differences between novels and films in terms of narrative point of view. Although it is shown by dividing into each chapter in novel and on connectivity in film, this paper finds out that both film and novel are shown the subject of reader's difference of the view point about 'author and director's identity'.

• Journal of Acupuncture Research
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• v.18 no.5
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• pp.60-69
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• 2001

Objective : Recent studies Suggested that there is a strong correlation between acupuncture stimulation and its related cortical activation. Anther study showed that either positive or negative BOLD effects could be observed depending on anatomical structure in acupuncture. Material and Methods : 1) Subjects and paradigms : Two separate stimulation paradigms were performed on five healthy (aged 22-23 yrs) in this study. First, the paradigm of acupuncture stimulation was that the acupuncture needle was inserted in acupoints KI6(照海), which is located in lateral side of the foot and then continuously twisted(補瀉를 除外한 捻轉法) for 70 seconds for 10 cycles of activation. During rest period (70 seconds), the needle was completed removed from acupoint. Total 60 cycles were performed and 10 images were obtained per cycle. Second, non-acupoint was randomly selected and the same paradigm was performed as acupoint stimulation. The stimulation protocol comprised 10 cycles of alternating activation and rest (10 images per cycle). Total 60 cycles were performed and each cycle take about 1.5 sec for motor task. Subjects take an at least 15 minutes break before starting anther paradigm. Conclusion : In this study, I investigated a new acupoint KI6(照海) which was known as motor - related acupoint and obtained an evidence that the stimulation of KI6(照海) resulted in negative BOLD response to stimulation.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.2
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• pp.172-179
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• 2015

The developmental mechanism of root formation is a complex process. Hereditary and environmental factors may affect the morphology of the developing root. A total of 12 cases was presented with permanent first molars with abberant root morphology. Clinically, these teeth appeared as a normal crown. However, radiographically, the root was slender, twisted and characterized by irregular lengths. In addition, root trunk length was shorter and pulp chamber was obliterated. In these cases, periapical radiolucency and loss of lamina dura were often observed. In 6 cases, an abnormal root of the primary second molars were also present, as well as root malformation of permanent first molars. In 3 cases, permanent central incisors also had a dysmorphic crown. These cases almost all had medical history, such as premature birth, brain infection or congenital heart disease in infants. The present paper describes cases of permanent first molars with an abnormal root that are rarely reported in literature. This case may intensify the variation in the permanent first molar and is intended to reinforce the clinician's awareness of rare morphology of the roots.