• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.197-199
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• 2004

In this paper, we studied a accuracy for CT using elastic epoxy. According to industry development, the quality where also the electric material is various is demanded. Insulation material is widely used because epoxy is superior to electrical and mechanical property. Until now, the possibility where the crack will occur is high because epoxy used to electrical products had high hardness. If thermal expansion is different of two material, contraction of epoxy heavily transformed turns ratio of CT. Elastic epoxy absorbed in expansion and contraction of substance material by temperature. So we could design more exacted CT. We had elastic test of elastic epoxy and made CT using elastic epoxy. At the result, We obtained turns ratio of within 4% superior to existing CT.

• Korea-Australia Rheology Journal
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• 제21권4호
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• pp.225-233
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• 2009

In various attempts to relate the behaviour of highly-elastic liquids in complex flows to their rheometrical behaviour, obvious candidates for study have been the variation of shear viscosity with shear rate, the two normal stress differences $N_1$ and $N_2$, especially $N_1$, and the extensional viscosity $\eta_E$. In this paper, we shall be mainly interested in 'constant-viscosity' Boger fluids, and, accordingly, we shall limit attention to $N_1$ and $\eta_E$. We shall concentrate on two important flows - axisymmetric contraction flow and "splashing" (particularly that which arises when a liquid drop falls onto the tree surface of the same liquid). Modern numerical techniques are employed to provide the theoretical predictions. It is shown that the two obvious manifestations of viscoelastic rheometrical behaviour can sometimes be opposing influences in determining flow characteristics. Specifically, in an axisymmetric contraction flow, high $\eta_E$ can retard the flow, whereas high $N_1$ can have the opposite effect. In the splashing experiment, high $\eta_E$ can certainly reduce the height of the so-called Worthington jet, thus confirming some early suggestions, but, again, other rheometrical influences can also have a role to play and the overall picture may not be as clear as it was once envisaged.

• 대한인간공학회지
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• 제34권4호
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• pp.313-326
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• 2015

Objective: The objective of this research is to quantitatively analyze muscle activities of arm and shoulder, according to direction in various types of one-handed manual material handling, based on surface electromyography. Background: Workers in industrial sites frequently carry out one-handed manual material handling using arm and shoulder muscles. Therefore, chronic load and accumulated fatigue occur to arm and shoulder muscles, which becomes a main cause of upper arm and shoulder musculoskeletal disorders. The shoulder muscles have widely range of motion, and complex interactions take place among various muscles including rotator cuff muscles. In this regard, research on interactions among should muscles, according to such various dynamic motions, is required. Method: Ten male subjects in their 20s participated in this research. This research considered upward, downward, leftward, rightward, forward and backward directions and fourteen muscles around arm and shoulder (biceps brachii and trapezius, etc.) as independent variables. The mean muscle activity was set as the dependent variable. This research extracted $4^{th}{\sim}7^{th}$ repetition signals according to ten times of repetitive muscle contraction, and analyzed the muscle activity concerned using the envelope detection technique. Results: The mean muscle activity of upward direction was analyzed highly statistically significant. The reason is that the effect of gravity works to arm and shoulder muscles. Also, it is conjectured that deformation of coracoacromial ligament was caused, and its contact pressure increased, due mainly to the shoulder flexion, and therefore load was analyzed high. Muscle activity was analyzed significantly low, according to concentric ballistic motion used in the concentric contraction phase by storing elastic energy in the eccentric contraction phase with a motion to bring the weight to the front of subject's body as to downward, leftward and backward directions. Because, elbow joint's flexion-extension motions mainly occurred, biceps brachii was analyzed high muscle activity as the prime mover. Conclusion: The information on the quantitative load of muscles can be applied to ergonomic work design for one-handed manual material handling to minimize muscle load. Application: This research has effectively identified muscle activity according to dynamic contraction by applying an envelope detection technique. The results can be used for ergonomic work design to minimize muscle load during the one-handed manual material handling, according to each direction. The research results are expected to be used for musculoskeletal disorder prevention and physiotherapy in the rehabilitation medical field, based on the muscle load of arm and shoulder in various directions.

• 한국초전도ㆍ저온공학회논문지
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• 제19권2호
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• pp.53-57
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• 2017

In superconducting power devices including power cables in which high temperature superconducting (HTS) tapes are utilized, a reliable electrical insulation should be achieved for its maximum performance. For an efficient design of HTS superconducting devices, a comparative evaluation of the mechanical and thermal propperties for various insulation materials at cryogenic temperatures is required. Especially, in the process of the property evaluation of the sheet-shaped insulation materials, anisotropy according to the machining direction should be considered because the mechanical and thermal properties are significantly influenced by the sample orientation. In this study, the cryogenic thermal and mechanical properties of various insulation material sheets such as PPLP, Cryoflex, Teflon, and Kapton were determined considering sample orientation. All samples tested at cryogenic temperature showed significantly higher tensile strength as compared with that of room temperature. The ultimate tensile strength at both temperature conditions significantly depended upon the sample orientation. The thermal properties of the insulation materials exhibited a slight difference among samples depending on the orientation: for the PPLP and Cryoflex, the CD orientation showed larger thermal contraction up to 77 K as compared to the MD one. MD samples in PPLP and Cryoflex showed a lower CTE and thermal contraction which made it more promising as an insulation material due to its comparable CTE with HTS CC tapes.

• The Journal of Korean Physical Therapy
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• 제11권1호
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• pp.149-156
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• 1999

Resistive therapeutic exercise prescription goal is to improve functional performance and capabilities through the development of increased muscular strengh endurance or power. Resistance can be applied to either dynamic or static muscle contractions. Resistive therapeutic exorcise can be carried nut concentrically, eccentrically, isometrically, isokinetically. Neurodevelopmental treatment has not resistive therapeutic exercise concept. But proprioceptive neuromuscular facilitate techniques have resistive therapeutic exercise concept with pattens and techniques. It is aid muscle contraction, motor control and increase strength. Manual muscle testing will help the therapist establish a qualitative and quantitative baseline level of strength. Manual resistance maybe applied a against controlled lengthening contraction re static contraction of a muscle. A repetition maximum is not easy to calculate and is not the most accurate method available today to measure strength before of after a resistive therapeutic exercise program. Oddvar Holten Diagram is essy to calculate and is the most accurate method available today to measure strength before of after a resistive therapeutic exercise program. Plyometric training emphasize the development of muscular power and coordination. Quick bursts of force in functional movement patterns are often necessary of a patient is to return to high-demand occupational, recreational or sports related activities.

• 한국의류학회지
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• 제20권5호
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• pp.930-942
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• 1996

This study was done to provide the characteristics of body surface changes at armhole area. Experiments were carried out at upper arm and upper body inchuding 67 items, 74 segments by the stanard posture and arm movements. The subjects were 15 females of twenty aged. The major conclusions of this study are; 1. On the circumference items of upper arm, armhole circumference was decreased by all arm movement, especially high contracted on front armhole line. The most contracted segments of armhole circumference were from the shonlder point to front and back interscye breadth point. Axillary circumference was increased 5 cm to the utmost, so the function of sleeve pattern would be decided by axillary circumference. 2. The lengths of upper arm were decreased near center line, sleeve cap length was contracted 3∼4 cm. Posterior armpit point area was increased both length and breadth. According to the rates of expansion and contraction, the diagram of expansion and contraction of upper arm was suggested. 3. On upper body, back side chest breadth was increased exceedingly and shoulder length was decreased most. It was apparent that surface changes of upper body were greatly larger as far away from center front and center back line. The rates of expansion and contraction of upper body were also represented as a diagram of surface changes.

• The Journal of Korean Physical Therapy
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• 제16권3호
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• pp.205-216
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• 2004

The purpose of this study is to find application of combination of insotonic(CI) in clinical approach. This is a literature study with books and clinical experience. CI was developed after Margaret Knott that is very useful in clinically. CI has two lever system. It has class II lever system for eccentric contraction and class III lever system for concentric contraction. Therefore it make two different contraction that is not only magnitude of motion and speed increase of motion but also biomechanical advantage. Application of CI has much variety by patient position and treatment position. Especially, it is very effectable on mat activities and training for mid stance period. CI apply in supine position on treatment table, mat or high mat activities, bridging activities, all fourth activities and sit on chair activities. CI apply serially with different techniques. These are rhythmic initiation, dynamic reversal, approximation, rhythmic stabilization and replication.

• KIEAE Journal
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• 제6권2호
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• pp.51-57
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• 2006

With people's awareness of environment-friendly buildings recently increasing, there is a need to develop environment-friendly construction materials to reduce indoorair pollution levels. Thus, efforts to develop loess finishing materials that can replace the finishing materials currently being used (e.g., gypsum boards and chemical products) are underway. An analysis of the characteristics of domestic loess products,however, revealed that the cracks on loess products can be lessened and their strength can be improved by adding chemical ingredients to them. Thus, this research sought to use 100% natural materials and to develop loess finishing materials. In the experiments that were conducted in this study, appropriate mixture ratios of loess and sand/silica sand were found, and cracks and contraction ratio changes in samples were analyzed by differentiating the ratios of natural ingredients, such as lime, fine jute threads, gypsum, and jute cuttings. Loess'particle size distribution was found to have a high correlation with loess decoration, and it was discovered that the mixture of lime and fine chute threads could improve the contraction ratio. Through this study, which made use of natural ingredients, environment-friendly construction materials that can exercise the original function of loess were developed.

• 대한물리의학회지
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• 제14권3호
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• pp.47-53
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• 2019

PURPOSE: This study measured the external pressure on abdomen during maximal inspiration. The study determined the correlation between the diaphragmatic contraction pressure and the lung capacities to verify whether or not the measured pressure values can represent diaphragmatic contractility. METHODS: The study included 32 healthy subjects (16 males and 16 females). The researchers fabricated their own diaphragmatic pressure belt (DiP Belt) to measure DCP. DiP Belt device was fixed on the front of the abdomen and the diaphragmatic contractility was measured during maximal inspiration. The lung capacities were measured using a portable digital spirometer device (Pony Fx, COSMED, Italy). A digital spirometer is a device that is used to test the flow of air entering and exiting the lungs. RESULTS: DCP showed significant positive correlations with vital capacity (VC), inspiratory reserve volume (IRV) and inspiratory capacity (IC). Among values of lung capacities, IC showed especially strong positive correlations with the DCP (r =.714, p<.010). For the males, DCP showed significant positive correlations with IRV and IC, and DCP showed significant negative correlation with the expiratory reserve volume (ERV). For the females, DCP showed significant positive correlation with tidal volume (VT), but any significant correlation was not found with any of the other values of lung capacities. CONCLUSION: DCP showed high correlations with IRV and IC associated with inspiratory capacity. Therefore, The DiP Belt can be looked upon as a simple device that is very useful for measuring diaphragmatic contractility.

• The Korean Journal of Physiology
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• 제26권2호
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• pp.123-128
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• 1992

The present study was undertaken to examine if endogenous nitric oxide is partly responsible for the high calcium induced vasorelaxation in vitro. Isolated porcine coronary arterial rings were suspended in the tissue chamber and their changes in isometric tension were recorded. KCI little affected the vascular tension in the calcium free media, but subsequent addition of cumulative doses of $CaCl_3$ from 1 to 40 mM caused a contraction followed by complete relaxation. The maximum tension was noted at the calcium concentration in the media of 5 mM, and then the tension progressively declined at 10-40 mM. The relaxation was slightly attenuated in the endothelium-denuded preparation. The relaxation was converted into a contraction by the addition of methylene blue. The relaxation response was not affected in the presence of indomethacin, but was significantly attenuated by $N^w-nitro-L-arginine$ methyl ester pretreatment. These results suggest that the calcium induced vasorelaxation is in part attributable to the release of endogenous nitric oxide.