• KSBB Journal
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• 제9권5호
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• pp.518-524
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• 1994

Cytodex III 마립담체를 이용하여 무혈청배지에서 인간선장 세포를 배양하였다. 무혈청애지에서 미립담체 표변에 세포들은 정상적으로 부착하고 확 산하면셔 세포들은 담체에서 담체로 이동하여 생육 하였다. 미립담체에 접착 수율은 1%의 혈청 을 포 함된 배지에서는 약 93%인 반면에 무혈청배지에 서는 85% 정도로 나타났다. 접착된 세포의 90% 이상이 유가식 및 연속배양에서 탐체의 표변에 접 착한 후 6시간 후에 확산하며 생육하였다. 유가식 배양에셔 서1포농도와 최대 scu-P A 농도는 각각 $9.1{\times}10^5$ cells/m!와 1790 IU/ml이였고 연속배양에 셔는 각각 $2.5{\times}10^6$ cells/m]와 1820 IU/ml로 나타났다. 또한 저혈청배지에셔는 scu-P A가 tc-P A로의 전환율이 10% 정도로 높은데 비교하여 무혈 청배지에서는 전환율이 4.8%로 낮은 것으로 나타났 다. 이처럼 무혈청배지는 저혈청배지에셔보다 낮은 tc-P A로의 전환율을 유지할 수 있는 이점이 었다.

• 한국농공학회논문집
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• 제62권4호
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• pp.63-73
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• 2020

The area of paddy fields for upland crop cultivation is gradually increasing. In this context, we developed a chain type mole drainer that can be attached to a tractor to prevent the wet injury of crops. To conduct a field test, we formed underdrains at 2 m intervals in a paddy field wherein soybeans are cultivated, and we investigated the status of the soil moisture, groundwater level, and soybean growth during the cultivation period. The soil moisture content decreased by 22.3~26.8% in the test plot and by 5.9~6.9% in the control plot during a period of 57~88 hour after a rainfall of 41.5~157.0 mm. The effect of underdrainage was clear as the hourly groundwater level decreased approximately 2.8 times faster in the test plot compared with the control plot. Moreover, the soybean yield was greater by 78.6 kg/10a in the test plot than in the control plot. Therefore, for soybean cultivation in paddy fields, the use of the developed mole drainer is expected to help in improving the drainage and increasing the soybean yield.

• Macromolecular Research
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• 제8권4호
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• pp.179-185
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• 2000

Generally vascular grafts with a relatively large inner diameter (> 5 mm) have been successfully employed for replacement in the human body. However, the use of small diameter grafts is limited, because these grafts rapidly occlude due to the thrombosis. The ideal blood-contacting surface of a prosthesis would be an endothelial cell (EC) lining, because the confluent monolayer of healthy ECs that culture natural blood vessels represents the ideal nonthrombogenic surface. For vascular graft application, the stable EC adhesion on surface under How conditions is very important. In this study, the adhesive strength of ECs attached on polymer surfaces coated with collagen type IV (Col IV), fibronectin (Fn), laminin (Ln), and treated with corona was investigated onto polyurethane (PU) films. The EC-attached PU surfaces were mounted on parallel-plate flow chambers in a How system prepared for cell adhesiveness test. Three different shear stresses (100, 150, and 200 dyne/㎠) were applied to the How chambers and each shear stress was maintained for 120 min to investigate the effect of shear stress and surface treatment condition on the EC adhesion strength. It was observed that the EC adhesion strength on the surface-modified PU films was in the order of Ln≡Fn > Col IV > corona 》 control. More than 70% of the adhered cells were remained on surface-modified PU surface after applying the shear stress,200 dyne/㎠ for 2 hrs, whereas the cells were completely detached on the control PU surface within 10 min after applying the same shear stress. It seems that the type of adsorbed proteins and hydrophilicitv onto the PU surfaces play very important roles for cell adhesion strength.

• PNF and Movement
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• 제19권2호
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• pp.279-285
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• 2021

Purpose: This study aimed to develop new digital navicular drop test (ND-NDT) equipment and to determine its validity and reliability. Methods: A total of 24 healthy male and female adults, who fully understood the purpose of the study and gave consent to participate in the study, were selected as participants. The NDT and ND-NDT were conducted in the dominant foot of the participants in a random order. For the NDT, the position of the navicular bone was marked with a pen first; then, the height of the navicular bone from the ground was measured in both sitting and standing positions. For the ND-NDT, after the sticker-type reflection markers were attached to the position of the navicular bone, the height of the navicular bone from the ground was measured in both sitting and standing positions. To assess the validity of the diagnostic tests, the same examiner measured the height of the medial longitudinal arch (MLA) three times in both the sitting and standing positions. To assess the inter-rater reliability of the ND-NDT, three examiners, in a random order, attached the sticker-type reflection markers to the position of the navicular bone and then measured the height of the MLA in both positions. Results: In the sitting position, the Pearson correlation coefficient (r) between the two diagnostic tests was very high (r = 0.97) and statistically significant. In the standing position, the Pearson correlation coefficient (r) between the two tests was 0.95, which was also statistically significant. The ICC_2,1 values in the sitting and standing positions were 0.93 and 0.95, respectively, indicating significantly high inter-rater reliability. Conclusion: The ND-NDT equipment showed very high diagnostic validity, as well as excellent inter-rater reliability, indicating the clinical usefulness of the equipment as a diagnostic system for confirming pes planus.

• 한국주조공학회지
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• 제14권6호
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• pp.530-540
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• 1994

Aluminium-silicon alloy(JIS AC8A) matrix composites reinforced with SiC particles were fabricated by spray-cast forming process, and the microstructure of powders and preforms produced were studied by using an optical and scanning electron microscopy. SiC particles were co-sprayed by mixed phase injection method during the spray casting process. Most of the composite powders formed by this mixed phase injection method exhibit morphology of particle-embedded type, and some exhibits the morphology of particle attached type due to additional attachment of the SiC particles on the surface of the powders in flight. The preforms deposited were resulted in dispersed type microstructure. The pre-solidified droplets and the deposited preform of SiC-reinforced aluminium alloy exhibit finer equiaxed grain size than that of unreinforced aluminium alloy. Eutectic silicons of granular type are crystallized at the corner of the aluminum grains in the preforms deposited, and some SiC particles seem to act as nucleation sites for primary/eutectic silicon during solidification. Such primary/eutectic silicons seem to retard grain growth during the continued spray casting process. It is envisaged from the microstructural observations for the deposited preform that the resultant distribution of SiC injected particles in the Al-Si microsturcture is affected by the amount of liquid phase in the top part of the preform and by the solidification rate of the preform deposited.

• 한국의류학회지
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• 제31권2호
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• pp.258-268
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• 2007

The purpose of this research is to develop functional midsole that can restrain the heightening of plantar pressure in forefoot pressure so as to develop high-heeled shoes that can lessen foot ailments among women. The pumps shoes used for the research were of the same pumps type last. The variant was heel height, 3cm, 6cm, and 9cm, and the shoes were made in both normal midsole and functional midsole. The variant was applied to investigate the changes of foot pressure on forefoot and hindfoot according to heel height.'Heel Cup' was chosen for modification of functional midsolepumps type. to enlarge contact area in hindfoot, and 'Heel Posting Pad' was attached under sustentaculum tali to suppress the weight moving to forefoot pressure. If such functional parts are developed and used, it is possible to lessen the amount of Pmax or Impulse imposed by high-heeled pumps type on forefoot pressure. This can greatly lessen foot ailments, largely caused by high-heeled shoes, among women.

• 설비공학논문집
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• 제24권1호
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• pp.16-22
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• 2012

Experimental investigations were carried out to examine the heat and mass transfer characteristics of LiCl aqueous solution for a plate heat exchanger type dehumidifier. Cooling dehumidification was adopted vertical type heat exchanger. Also non woven fabric is attached surface of the heat exchanger for spreadability of LiCl aqueous solution. Mass flow-rate of LiCl aqueous solution and concentration were selected as experimental conditions. Also, In this study, the effects of relative humidity of process air and velocity were investigated experimentally. As a result of heat transfer coefficient and mass transfer coefficient of were increased film reynolds number increased. heat transfer coefficient and mass transfer coefficient of LiCl aqueous solution were 0.14~0.24 kW/$m2^{\circ}C$ and $1.3{\times}10-63{\sim}6.2{\times}10-6$ m/s respectively.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 추계학술대회 논문집
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• pp.323-328
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• 2003

A basic design on a flexible riser in a floating type development system for upwelling deep ocean water is presented. In the numerical study, an implicit finite difference algorithm is employed for three-dimensional riser equations. Fluid and geometric non-linearity and bending stiffness are considered and solved by Newton-Raphson iteration. To keep the depth of end point of a flexible and light riser is very important for upwelling deep ocean water in a floating type development system. Weight attached at the end point of the riser in order to keep its intake depth is designed under the strong surface current and the configuration of the riser is predicted. The results of this study can be contributed to the design of the development system in floating type for upwelling deep ocean water.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1564-1570
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• 2007

There are normally two types of the energy absorbers used in the crashworthiness of trains. The first is a structure type, which mainly used in not only the primary structures of the train but also the crash energy absorbers at the accident. The second is a module type, which just absorbs the crash energy independent of the primary structures and attached to the structures of the train. The expansion and inversion tube are widely used as the module type crash energy absorbers, especially in the train. The tubes should not be buckled under the load acting on the end of the tube in longitudinal direction during absorbing the crash energy. The buckling stability of the tubes is affected by the boundary conditions, thickness and length of tube. In this study, the effects of the length and thickness of the tubes on the buckling load are studied by using the ABAQUS, a commercial finite element analysis program, and then presents the guideline to design the tube. The analysis processes to compute the buckling load consist of a linear buckling analysis and a nonlinear post-buckling analysis. The buckling modes are evaluated by the linear buckling analysis, as using these modes, the buckling loads are computed by the nonlinear post-buckling analysis.

• 한국정밀공학회지
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• 제30권11호
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• pp.1187-1192
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• 2013

In the case of 4 wheel drive (4-WD) type car, power switching occurs to 4-WD by operating lever or switch that operates power switching device attached in transfer case which can operate motor by electric signal. So if the RPM of motor is high, power switching will not exactly occur and can cause damage to gear in transfer case according to circumstances. So in this study, we applied 2 level of planet gear type motor spindle of motor drive part of a power train. And conducted decelerating to increase torque to switch power safe and accurately. Also, we researched efficiency of gear by designing reduction gear ratio and gear type and by calculating contact stress and bending strength. Based on researched content, we made drive head of power switching device and a reduction module which uses type that uses motor spindle as sun gear and ring gear as cover.