• Title/Summary/Keyword: TAV

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Nondestructive Evaluation of Semi-Insulating GaAs Wafer Surface Properties Using SAW (SAW를 이용한 반절연 GaAs웨이퍼 표면 성질의 비파괴 측정)

  • Park, Nam-Chun;Park, Sun-Kyu;Lee, Kuhn-Il
    • The Journal of the Acoustical Society of Korea
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    • v.10 no.3
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    • pp.19-30
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    • 1991
  • The surface properties such as energy gap, exciton, shallow trap level, deep trap level, type inversion with annealing and metastable state of $EL_2$ level of SI GaAs wafers and the conductivity distribution of 2 inch Cr doped GaAs wafer were investigated using nondestructive TAV(transverse acoustoelectric voltage) technique. The TAV is generated when SAW and semiconductor interact. We also have tried newly SAW oscillator technique to investigate the surface properties of semiconductor wafers and we have shown the validity of this technique.

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A Study on the Implementation of RFID for Korean Defense (RFID 군 적용방안 연구)

  • Lee, Jea-Youl;Kim, Seong-Won;Choi, Sang-Young
    • Journal of the military operations research society of Korea
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    • v.31 no.1
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    • pp.58-72
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    • 2005
  • RFID(Radio Frequency Identification) is one of key technologies in ubiquitous computing. RFID system comprises tag, reader, and computer application. The tag is a small electronic chip, which is attached to a thing such as item, pallet, container. The reader has an tiny antenna obtaining the identification information of the things by radio frequency, and provides the information to the computer application for a business. In this paper we have proposed the military application of RFID and its implementation policy for the Korean armed forces. We believe that The principle application area would be logistics TAV(total asset visibility) and resource management, and the implementation should be achieved step by step considering the advancement of RFID technology and government policy.

Clinical Implication of Aortic Wall Biopsy in Aortic Valve Disease with Bicuspid Valve Pathology

  • Kim, Yong Han;Kim, Ji Seong;Choi, Jae-Woong;Chang, Hyoung Woo;Na, Kwon Joong;Kim, Jun Sung;Kim, Kyung-Hwan
    • Journal of Chest Surgery
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    • v.49 no.6
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    • pp.443-450
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    • 2016
  • Background: Although unique aortic pathology related to bicuspid aortic valve (BAV) has been previously reported, clinical implications of BAV to aortopathy risk have yet to be investigated. We looked for potential differences in matrix protein expressions in the aortic wall in BAV patients. Methods: Aorta specimens were obtained from 31 patients: BAV group (n=27), tricuspid aortic valve (TAV) group (n=4). The BAV group was categorized into three subgroups: left coronary sinus-right coronary sinus (R+L group; n=13, 42%), right coronary sinus-non-coronary sinus (R+N group; n=8, 26%), and anteroposterior (AP group; n=6, 19%). We analyzed the expression of endothelial nitric oxide synthase (eNOS), matrix metalloproteinase (MMP)-9, and tissue inhibitor of matrix metalloproteinase (TIMP)-2. Results: Based on the mean value of the control group, BAV group showed decreased expression of eNOS in 72.7% of patients, increased MMP-9 in 82.3%, and decreased TIMP in 79.2%. There was a higher tendency for aortopathy in the BAV group: eNOS $(BAV:TAV)=53%{\pm}7%:57%{\pm}11%$, MMP-9 $(BAV:TAV)=48%{\pm}10%:38%{\pm}1%$. The AP group showed lower expression of eNOS than the fusion (R+L, R+N) group did; $48%{\pm}5%$ vs. $55%{\pm}7%$ (p=0.081). Conclusion: Not all patients with BAV had expression of aortopathy; however, for patients who had a suspicious form of bicuspid valve, aortic wall biopsy could be valuable to signify the presence of aortopathy.

Degradation Properties of a Bi-layered Cross-linked Collagen Membrane for Localized Bone Regeneration: In Vitro and In Vivo Study

  • Park, Jin-Young;Lee, Jae-Hong;Cha, Jae-Kook;Lee, Jung-Seok;Jung, Ui-Won;Choi, Seong-Ho
    • Journal of Korean Dental Science
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    • v.14 no.1
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    • pp.12-25
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    • 2021
  • Purpose: (i) To evaluate the biologic properties of a bi-layered 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride-cross-linked collagen membrane (CCM) in vitro. (ii) To assess the efficacy of CCM for localized bone regeneration in vivo. Materials and Methods: Biodegradation of CCM compared to a native collagen membrane (NCM) was assessed in vitro. In vivo, twelve male New Zealand White rabbits were used. Four calvarial, circular defects (diameter 8 mm) were created in each animal. The sites were randomly allocated to i) CCM+biphasic calcium phosphate (BCP) (CCM-BCP group), ii) CCM alone (CCM), iii) BCP alone (BCP) and, iv) negative control (control). Animals were sacrificed at 2 (n=6) and 8 weeks (n=6). Outcome measures included: micro-computed tomography (μCT) analysis (total augmented volume [TAV], new bone volume) and histomorphometry (total augmented area [TAA], newly formed bone, remaining membrane thickness [RMT]). Result: CCM was more resistant to degradation than NCM. μCT analysis showed CCM-BCP (196.43±25.30 mm3) and BCP (206.23±39.13 mm3) groups had significantly (P<0.01) larger TAV than the control (149.72±12.28 mm3) after 8 weeks. Histomorphometrically, CCM-BCP group (17.75±5.97 mm2) had significantly (P<0.01) greater TAA compared to the CCM group (7.74±2.25 mm2) and the control (8.13±1.81 mm2) after 8 weeks. After 8 weeks, RMT was reduced by 67%. Conclusion: CCM can be a favorable choice of barrier membrane when performing guided bone regeneration (GBR) in localized bone defects. CCM has better resistance to degradation than the natural collagen membrane, in vitro. In vivo, CCM provides an advantageous integration of prolonged barrier function and biocompatibility for GBR.

Assessment of pharyngeal airway in Korean adolescents according to skeletal pattern, sex, and cervical vertebral maturation: A cross-sectional CBCT study

  • Elagib, Tassneem;Kyung, Hee-Moon;Hung, Bui Quang;Hong, Mihee
    • The korean journal of orthodontics
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    • v.52 no.5
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    • pp.345-353
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    • 2022
  • Objective: To investigate airway volumes using cone-beam computed tomography (CBCT) by skeletal patterns, sex, and cervical vertebral maturation (CVM) stages in Korean adolescents. Methods: The sample consisted of pretreatment CBCT and cephalograms of 95 adolescents (aged 12-19) obtained out of 1,611 patients examined for orthodontic treatment from 2018 to 2020 in Kyungpook National University Dental Hospital. The samples were classified into two sex groups; three skeletal pattern groups, four chronological age groups and four CVM stages. Nasopharyngeal volumes (NPV), oropharyngeal volumes (OPV), total pharyngeal airway volume (TAV) and minimum cross-sectional area (MCA) measurements were taken from the CBCT. Multiple linear regression analyses to find out which one of the independent variables are good predictors for airway variables. Significant factors were analyzed by two-way multivariate analysis of variance (MANOVA) then multiple comparisons were analyzed using a t-test, and Fisher least significant difference. Results: Age, sex, CVM, and Sella-Nasion-B point have significant influence on airway variable. Males and females showed similar patterns of change in chronological age groups 1-3; however, males had larger NPV, OPV, and MCA at CVM in group 4. According to CVM stages, males had larger OPV, TAV, and MCA at CVM stage 6 (p-value: 0.019, 0.021, 0.015, respectively) and no sex differences at CVM stages 3, 4, and 5. Conclusions: Skeletal patterns have an effect on airway volume. Sex differences were found in CVM 6.

Molecular characterization of Cucumber mosaic virus isolates isolated in Korea

  • Park, Jang-Kyung
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.4-8
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    • 2003
  • Cucumber mosaic virus (CMV) belongs to genus Cucumovirus. The Cucumovirus group contains three distinct members: CMV, Tomato aspermy virus (TAV), and Peanut stunt virus (PSV). The type member, CMV is the most widespread and most studied. CMV is isometric particles about 30 nm in diameter. The genome of CMV is divided into three RNAs. In addition, RNA extracted from virus particles contains a fourth RNA that is a subgenomic RNA generated from RNA3. RNA1 and RNA2 are each encapsidated in separate particles, whereas RNAs3 and 4 are coencapsidated in a third particle. Hence, inoculation by three particles, transmitted either mechanically or by the aphid vector, is required to infect plants.(중략)

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A Study on the Prediction of Clothing formability of Men's Shirts from Mechanical Properties (직물의 역학적 특성으로부터 셔츠의 의복형성성 예측에 관한 연구)

  • 권오경;권헌선;장수정
    • Journal of the Korean Home Economics Association
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    • v.39 no.11
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    • pp.223-232
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    • 2001
  • This study, by explaining the relationship between mechanical properties and clothing formability, aims to propose functional data for tailoring performance of fabrics of good tailorability. The KES-FB system was used to measure factors of mechanical properties and also the technique of stepwise-block-regression method was applied to investigate relationship between functional properties and mechanical properties of men's shirks. As results of vasual inspection of men's shirts, it showed that good fabrics had higher value in the LT, bending properties, shear properties and RC than poor fabrics in Total Appearance Value(TAV). And finally, A formula was obtained for calculating the VIA of men's shirts from functional properties which were calculated from the mechanical properties.

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A Biomechanical Analysis of 540o Dwihuryeochagi of Taekwondo (태권도 540도 뒤후려차기 동작의 운동역학적 분석)

  • Kang, Dong-Kwon;Kang, Suh-Jung;Yu, Yeon-Joo
    • Korean Journal of Applied Biomechanics
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    • v.23 no.1
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    • pp.19-24
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    • 2013
  • The aim of the study was a quantitative analysis of elite athlete's $540^{\circ}$ Dwihuryeochagi and effects of ground movements to the jumping height and kicking velocity. Eleven elite players(Taekwondo demonstration team) participated in this study. In order to get the kinetic and kinematic variables, ten Vicon cameras and a force plate were used. Foot segment velocity(FSV), vertical ground reaction force(GRF), impulse, ground time(GT) in phase 1, trunk angular velocity(TAV), vertical center of gravity(COG), flight time(FT) in phase 2 and kicking leg segment velocity(KSV) in phase 3 were measured and analyzed. Results indicated that there were similar patterns of variables among phases between subjects. Non-significant correlation(r=.145) between flight time(FT) and impulse was found. Also non-significant correlation(r=.119) between center of gravity(COG) and impulse was found. In conclusions, there were similar strategies in phase 1, phase 2, and phase 3 between subjects.

Tangible Tele-Meeting in Tangible Space Initiative

  • Lee, Joong-Jae;Lee, Hyun-Jin;Jeong, Mun-Ho;Jeong, SeongWon;You, Bum-Jae
    • Journal of Electrical Engineering and Technology
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    • v.9 no.2
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    • pp.762-770
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    • 2014
  • Tangible Space Initiative (TSI) is a new framework that can provide a more natural and intuitive Human Computer Interface for users. This is composed of three cooperative components: a Tangible Interface, Responsive Cyber Space, and Tangible Agent. In this paper we present a Tangible Tele-Meeting system in TSI, which allows people to communicate with each other without any spatial limitation. In addition, we introduce a method for registering a Tangible Avatar with a Tangible Agent. The suggested method is based on relative pose estimation between the user and the Tangible Agent. Experimental results show that the user can experience an interaction environment that is more natural and intelligent than that provided by conventional tele-meeting systems.

Garment Appearance and Formability of Perspiration Absorption and Fast Dry/breathable Fabrics for Sports Wear (스포츠 웨어용 흡한속건 및 투습방수 소재의 의류외관 특성과 형성성능)

  • Kim, Hyun Ah
    • Fashion & Textile Research Journal
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    • v.21 no.5
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    • pp.597-605
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    • 2019
  • This paper examined the garment formability and appearance of perspiration absorption, fast dry, and breathable fabrics. The mechanical properties and seam pucker properties of these fabrics were measured and regression analysis was conducted between fabric structural parameters and their mechanical and seam pucker properties. The superior total appearance value (TAV) of fast dry knitted fabrics for sports-wear was achieved in fabrics with high extensibility and bending rigidity; consequently, it increased with increasing stitch density and tightness factor. The formability of the fast dry knitted fabric also improved with an increasing stitch density and tightness factor. The seam pucker was influenced by bending rigidity and a good seam pucker was exhibited in the fast dry knitted fabrics with low stitch density and tightness factor. However, the formability (F) of the breathable fabric improved by increasing extensibility and bending rigidity that decreased with an increasing cover factor and the thickness of the breathable fabric. In addition, seam pucker deteriorated with an increasing cover factor and the thickness of the breathable fabric, which was similar to the results of the formability predicted in fabric mechanical properties. A superior seam pucker was achieved in fabrics with high extensibility and low bending rigidity.