• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.199-200
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• 2021

In the study, creep and dry shrinkage characteristics were evaluated to determine the material properties necessary for structural analysis such as column shortening and differential drying shrinkage. All the experiments were conducted in an constant temperature and humidity room. The mechanical properties as well as the specific creep and ultimate dry shrinkage values were derived. In addition the characteristics of the physical value of the high-strength fiber reinforced concrete were considered.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.516-526
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• 2004

Polymerization shrinkage of photoinitiation type composite resin cause several clinical problems. The purpose of this study was to evaluate the shrinkage strain stress, linear polymerization shrinkage, compressive strength and microhardness of recently developed composite resins. The composite resins were divided into four groups according to the contents of matrix and filler type. Group I : $Denfil^{TM}$(Vericom, Korea) with conventional matrix, Group II : $Charmfil^{(R)}$(Dentkist, Korea) with microfiller and nanofller mixture, Group III : $Filtek^{TM}$ Z250(3M-ESPE, USA) TEGDMA replaced by UDMA and Bis-EMA(6) in the matrix, and Group IV : $Filtek^{TM}$ Supreme(3M-ESPE, USA) using pure nanofiller. Preparation of acrylic molds were followed by filling and curing with light gun. Strain gauges were attached to each sample and the leads were connected to a strainmeter. With strainmeter shrinkage strain stress and linear polymerization shrinkage was measured for 10 minutes. The data detected at 1 minute and 10 minutes were analysed statistically with ONE-way ANOVA test. To evaluate the mechanical properties of tested materials, compressive hardness test and microhardness test were also rendered. The results can be summarized as follows : 1. Filling materials in acrylic molds showed initial temporary expansion in the early phase of polymerization. This was followed by contraction with the rapid increase in strain stress during the first 1 minute and gradually decreased during post-gel shrinkage phase. After 1 minute, there's no statistical differences of strain stress between groups. The highest strain stress was found in group IV and followed by group III, I, II at 10 minutes-measurement(p>.05). In regression analysis of strain stress, group III showed minimal inclination and followed by group II, I, IV during 1 minute. 2. In linear polymerization shrinkage test, the composite resins in every group showed initial increase of shrinkage velocity during the first 1 minute, followed by gradually decrease of shrinkage velocity. After 1 minute, group IV and group III showed statistical difference(p<.05). After 10 minutes, there were statistical differences between group IV and group I, III(p<.05) and between group II and group III(p<.05). In regression analysis of linear polymerization shrinkage, group II showed minimal inclination and followed by group IV, III, I during 1 minute. 3. In compressive strength test, group III showed the highest strength and followed by group II, IV, I. There were statistical differences between group III and group IV, I(p<.05). 4. In microhardness test, upper surfaces showed higher value than lower surfaces in every group(p<.05).

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.287-291
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• 2018

The CNTFET, which is attracting attention as a next-generation semiconductor device, can obtain ballistic or near-ballistic transport at a lower voltage than that of conventional MOSFETs by depositing CNTs between the source and drain of the device. In order to increase the performance of the CNTFET, a large number of CNTs must be deposited at a high density in the CNTFET. Thus, various manufacturing processes to increase the density of the CNTs have been developed. Recently, the Directional Shrinking Transfer Method was developed and showed that the current density of the CNTFET device could be increased up to 150 uA/um. So, this method enhances the possibility of implementing a CNTFET-based integrated circuit. In this paper, we will discuss how to evaluate the performance of the CNTFET device compared to a MOSFET at the circuit level when the CNTFET is fabricated by the Directional Shrinkage Transfer Method.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.709-712
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• 2008

RC super tall buildings are planned and constructed recently in domestic area. Concrete is characterized by time dependant material such as creep and shrinkage. For this properties of concrete, differential shortening is one of the main issues on super tall buildings construction. This study includes material research, which is performing as a pre design stage to solve differential shortening on Lotte Super Tower Jamsil core structure(50, 60, & 70 MPa). The major part of this study is composed with comparison and analysis between experimental data and predicted data on total shrinkage and total compliance which were used on design stage. Four models, ACI209R Model, Ba${\check{z}}$ant-Baweja B3 Model, CEB MC99 Model, & GL2000 Model, were employed to predict them. It also tries to seek a proper model for high strength and high performance concrete in the case of no concrete test.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.188-194
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• 2002

버섯의 감압건조시험을 할 수 있는 요인시험장치를 제작하여 시험한 결과를 요약하면 다음과 같다. 가. 댐퍼조절방식 감압건조장치로 건조시험한 결과, 표고버섯은 건조온도 5$0^{\circ}C$에서는 나타나 건조실 압력에 따른 건감률의 변화는 크게 나타나지 않았으나, 건조온도 6$0^{\circ}C$에서 건조실 내부압력이 990hPa일 때 4.57%/hr로 1,013hPa에 비해 높게 나타났으며, 색차면에서는 온도 5$0^{\circ}C$일 때 건조실 내부 압력이 낮아질수록 변화가 적은 것으로 나타났고, 수축률은 압력별로 거의 변화가 없었으나, 건조온도 6$0^{\circ}C$, 압력 990hPa에서 다른 조건에 비해 양호한 것으로 판단되었으나 건조실 내부에 공기분배가 일정하지 않고, 건조실 내부압력 강하성능이 떨어지는 문제점이 발생하여 솔레노이드를 이용한 압력조절방식으로 보완 제작하여 건조시험을 실시하였다. 나. 솔레노이드방식 감압건조장치로 건조시험 한 결과, 표고버섯은 열풍온도 5$0^{\circ}C$, 건조실 내부압력 940-980hPa에서 건감률 2.69%w.b./hr, 갓의 복원률 90.1%로 가장 높았고, 색차 및 수축률이 가장 낮은 것으로 나타났으며, 건조실 내부압력을 900-940hPa로 고정하고 열풍온도를 40, 50, 6$0^{\circ}C$로 표고버섯을 시험한 결과 건감률은 6$0^{\circ}C$일 때 가장 높았으나, 색차, 수축률, 복원률을 고려할 경우 열풍온도 5$0^{\circ}C$가 가장 적합한 것으로 판단된다. 다 솔레노이드방식 감압건조장치로 건조한 표고버섯으로 품위에 대한 유의성 검증결과, 표고버섯의 경우 온도별로는 색택과 복원률, 건조실 내부 압력별로는 수축률, 복원률에서 유의차가 있는 것으로 나타났다. 라. 본 연구에서 구명된 감압건조특성을 기초로 하여 배치식 감압건조기를 설계 제작에 활용하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1213-1220
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• 2013

The purpose of this study was to identify the effect of the Smart Care ubiquitous healthcare service on hypertension management. Fifty one patients with inadequately controlled blood pressure (Systolic Blood Pressure ${\geq}$ 140 mmHg despite prescribed antihypertensive medication) from 4 local clinics participated in this study. Remote biometric monitoring and healthcare consultation via videophone was provided to the participants during 24 week - Smart Care service. The average number of blood pressure monitoring and the average day of remote consult using Smart Care Service system was 121 and 14.8 per participant. As a result of analyzing change in blood pressure during 24 weeks, there was a significant difference in blood pressure between baseline and 24 weeks. Systolic blood pressures of 86.3% participants were dropped within a normal range at 24 week. Smart Care u-health service could be effective in reducing blood pressure.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.2
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• pp.169-174
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• 2011

Acoustic emission (AE) signals were detected and analyzed in real time during the polymerization shrinkage of composite resin restoration in an artificial dental ring with a class I cavity. Most AE hit events were observed in the initial curing period of the 1st region with high contraction rate. The range of the $2^{nd}$ region for the stainless steel specimen was shorter than that for the PMMA specimen but longer than that for the human dentin specimen. AE hit events showed a blast-type signal having an amplitude in the range of 25.45 dB and a frequency band of 100.200 kHz or 240.300 kHz. These values of amplitude and frequency indicated the fracture of resin or of the adhesive layer.

• YAKHAK HOEJI
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• v.22 no.3
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• pp.163-174
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• 1978

Plantaginis seed has been applied in Chinese medicine a as well as in folk remedy. It was advocated that Plantaginis S Semeη exerts good therapeutic effects as anti-inflammatory, antitussive, obstipant and diuretic agent in some cases of alimentary, respiratory a and renal disorders. This study was carried out in order to r re-evaluate the pharmacological action, especially the hypotensive a action of Plantaginis Semen and to elucidate the mechanism of its a action, making use of Plantaginis Semen methanol extract (PME), because its basic pharmacological action, i. e., hypotensive action is n not clear. 1) PME, when administered into intravenous route, elicited the h hypotensive response dependent on the dose of PME given to the rabbit anesthetized with urethane. 2) This hypotensive response of P PME was inhibited by atropine and potentiated by physostigmine, but not influ$\varepsilon$need by vagotomization. 3) Depressor effect of PME was blocked by chlorisondamine, phentolamine, and bethanicline, while not altered by cyproheptadine, diphenhydramine and propran¬olol. 4) The secondary pressor response after blocking the depressor e effect of PME by chlorisondamine was produced, but this pressor response was deminished by atropine. 5) PME augmented the pressor e effect of norepinephrine and angiotensin, on the other hand, reduced b blood pressure elevated by carotid occlusion reflex. 6) These observa¬t tions suggest that PME may induce the hypotensive response via dual mechanisms of parasympathomimetic and sympatholytic action, that the positions of this action are cholinergic peripheral site and sympathetic ganglia respectively, and that PME may possess the pressor activity caused by stimulation of "atropine-sensitive site" which seems to existsin the sympathetic ganglia.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.310-320
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• 2003

To study the nutritional and health status of the elderly in Songnam, the anthropometic measurments, fat composition of body(FAT), blood pressure(BP) and blood test for analyzing biochemical indies of the elderly in seongnam were carried out in 338 free-living elderly (161 men, 177 women) aged from 58 to 92. Anthropometric measurements and blood pressure were assessed, and body fat was analyzed by BI(Bioelectrical Impedence) method. Biochemical measurements including blood glucose(BG), GPT, serum total cholesterol(TC) and albumin(AL) were analyzed. Average heights of the subjects were lower than the standards established in the Korean Recommended Dietary Allowances, and average weights were similar to the standards. FAT were significantly higher in women(36.4%) than men(27.7%), and both groups showed higher values than the reference. Mean systolic BP levels of men and women were 153.3mmHg and 153.7mmHg, and diastolic BP levels were 87.5mmHg and 86.0mmHg, respectively, and there were no significant differences between the sex. Mean BG levels of men and women were 115.9mg/㎗ and 123.7mg/㎗, respectively, and there were no significant differences between the sex and among the age groups. Mean GPT levels of men and women were 19.4unit and 18.1unit, respectively, and women older than 75 years showed significanly low levels of GPT compared to other women's age groups. Mean TC levels of men and women were 186.0mg/㎗ and 206.6mg/㎗, respectively, and significantly higher TC levels were shown in women than men. Mean AL levels of men and women were 4.8g/㎗ and 4.8g/㎗, respectively, and men aged 50 ∼ 64 years showed significant high AL levels compared to other age groups of men. It was suggested that nutrition education program was a good way to improve health status of the elderly.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.130-134
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• 2010

The effects of design parameters of supersonic ejector system under the assumption of constant pressure mixing were performed. Design parameters were mass flow rate ratio, area ratio between primary and secondary flow, and primary Mach number. 1-D theoretical performance of ejector in terms of pressure ratio and contraction ratio with and without loss mechanism such as diffuser efficiency and friction were considered.