• Title/Summary/Keyword: 반전법

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The electrical conduction and DC breakdown properties of $(Sr.Pb)TiO_3$-based ceramic ($(Sr.Pb)TiO_3$계 세라믹의 전기전도 및 DC절연파괴 특성)

  • 김충혁;정일형;이준웅
    • Electrical & Electronic Materials
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    • v.5 no.4
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    • pp.421-429
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    • 1992
  • 본 연구에서는 (Sr.Pb)TiO$_{3}$계 세라믹을 고압용 세라믹 캐패시터로 응용하기 위하여 일반적인 세라믹 소성법으로 제작하였으며 Bi$_{2}$O$_{3}$. 3TiO$_{2}$의 첨가량에 따른 전기전도 및 DC 절연파괴 특성을 조사하였다. 전도전류는 측정온도의 상승과 Bi$_{2}$O$_{3}$.3TiO$_{2}$의 첨가량이 증가함에 따라 상승하였다. 실온에서 전도전류는 전계에 따라 3영역으로 나누어졌다. 전계 15[kV/cm]이하의 영역에서는 오음의 법칙이 성립하는 이온전도가 나타났으며 전계 15[kV/cm]~40[kV/cm]인 영역에서는 전계에 강요된 강유전성 분극의 반전게에 기인하여 전류의 포화현상이 나타났다. 전계 40[kV/cm] 이상의 영역에서는 공간전하제한전류에 관련된 차일드법칙이 성립하였다. DC 절연파괴 강도는 측정온도의 상승과 Bi$_{2}$O$_{3}$.3TiO$_{2}$의 첨가량이 증가함에 따라 감소하였다. 온도 100[.deg.C] 이하에서는 전자적파괴가 일어났으며 100[.deg.C] 이상에서는 주울열과 유전손실에 의한 열적파괴가 나타났다.

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Effect on Balance Ability of Knee Osteoarthritis by Lower Extremity Patterns with dynamic reverse in Proprioceptive Neuromuscular Facilitation (PNF 하지 패턴 중 동적반전(dynamic reverse) 기법이 퇴행성 슬관절염 환자의 균형능력에 미치는 영향)

  • Jung, Hyun-Sung;Jeon, Ho-Young;Bae, Sung-Soo
    • PNF and Movement
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    • v.4 no.1
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    • pp.27-36
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    • 2006
  • Purpose : The main purpose of this study was to investigate the effect on Balance Ability of Knee Osteoarthritis(OA) by Lower Extremity Patterns with dynamic reverse in Proprioceptive Neuromuscular Facilitation(PNF). Methods : The subjects were consisted of 30 women patients with knee OA. All subjects were randomly assigned to PNF group. Each group had a treatment for 30 minutes per day and three times a week during 8 weeks period. Was used to measure recovery or worse of patient's condition, muscle assessment questionnaire(MAQ) was used to measure patient' s muscular strength, Endurance, coordination/balance, KWOMAC was used to pain, stiffness, and physical function, and BPM was used to measure path, anterior-posterior. Results : This study results in following conclusons. 1. MAQ score was significantly decreased in PNF group(p<.05). 2. KWOMAC score was significantly decreased in PNF group(p<.05). 3. BPM were score was significantly decreased in PNF group(p>.05). Conclusion : From this result the PNF treatment retrogression characteristic will be effective in treatment of patient, with the arthritis and widely may be applied at a therapist.

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Variation of SiC/C FGM Layers (SiC/C 경사기능재료 증착층의 변화)

  • Kim, Yu-Taek;Jeong, Sun-Deuk;Lee, Seong-Cheol;Park, Jin-Ho
    • Korean Journal of Materials Research
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    • v.8 no.6
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    • pp.477-483
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    • 1998
  • $SiC_{4}$$C_{3}$$H_{ 8}$$H_{2}$$C_{3}$$H_{8}$ $H_{2}$, $CH_{3}$$SiCI_{3}$$CH_{4}$$H_{2}$계를 사용하여 흑연기판 위에 SiC와 SiC/C FGM을 CVD법에 의해 코팅하였다. $SiCI_{4}$$C_{3}$$H_{8}$ $H_{2}$ 계에서 SiC 증착 시 바람직한 수소의 비는 10-30사이였고 결정 배향성은 입력가스의 탄소비에 따라 여러번의 대 반전이 일어났다. 성장조건을 {111} 배향성을 갖도록 조절하는 것이 FGM층간 접착상태를 증진시킬 수 있는 방법으로 판단되었다. $CH_{3}$$SiCI_{3}$C$_{3}$$H_{8}$ $H_{2}$ 계에서는 SiC와 C의 비율을 조절하기가 $SiCI_{4}$$C_{3}$$H_{8} $H_{2}$계를 사용했을 때 보다 용이하였고, FGM 단면 관찰에서 층간의 뚜렷한 경계를 발견할 수 없을 정도로 우수한 층간 접착상태를 보였다.

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The effect of a balance on deep abdominal muscles in an acute hemiplegic patient through stabilizing reversal, chopping and lifting (안정적 반전, 내려치기 그리고 들어올리기를 통한 하부체간 심층근육 강화운동이 초기 편마비 환자의 균형에 미치는 영향 - 증례 보고 -)

  • Jeon, Yoon-Seon;Lee, seung-hoon;Goo, Bong-Oh
    • PNF and Movement
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    • v.7 no.4
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    • pp.37-43
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    • 2009
  • Purpose : The purpose of this study was to evaluate the effect of core stability training at deep abdominal muscle for balance control of hemiplegic patient. Method : The subject of this study was a 47-year-old man with right hemiplegia. He was treated five times a week for three weeks with core stability training at deep abdominal muscles. Evaluation tool was used Functional reach test(FRT), timed up and go test(TUG) and one leg standing for stroke patients. Result : The FRT distance increase, TUG time decrease, one leg standing time increase core stability training at deep abdominal muscles for right hemiplegia improved was the ability for maintain balance. Posture and control of trunk stability are changing posture, and so which showed significant improve of total balance control. Conclusion : The result of this study showed that core stability training at deep abdominal muscles is an effective treatment for balance control. Therefore, it could be considered as a treatment method in the rehabilitation of stroke patient with poor postural control and imbalance, although further studies are needed.

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Orthoscopic real image reconstruction in integral imaging by modifying coordinate of elemental image (집적영상에서 요소영상의 좌표변환을 이용한 정치실영상 구현)

  • Jang, Jae-young;Cho, Myungjin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.7
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    • pp.1646-1652
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    • 2015
  • In this paper, we propose a depth conversion method for orthoscopic real image reconstruction in integral imaging. Pseudoscopic image has been regarded a problem in conventional integral imaging. the depth of reconstructed image is depending on a coordinate of an elemental image. The conversion from pseudoscopic to orthoscopic may be possible by analysing the geometrical relation between pickup and reconstruction system of elemental image. The feasibility of the proposed method has been confirmed through preliminary experiments as well as ray optical analysis.

Electrical properties of the PLZT thin film capacitors by the sol-gel method (Sol-gel법을 이용한 PLZT박막 커패시터의 전기적 특성)

  • 박준열;정장호;이성갑;이영희
    • Electrical & Electronic Materials
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    • v.9 no.7
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    • pp.668-673
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    • 1996
  • In this paper, (P $b_{1-x}$ L $a_{x}$)(Z $r_{0.52}$ $Ti_{0.48}$) $O_{3}$ (X=0-13[at%]) thin film were prepared by the Sol-Gel method, Multiple PLZT thin films were spin-coated on the Pt/Ti/ $SiO_{2}$Si substrate. The electrical properties of the films were investigated for varying the annealing temperature. In the PLZT(11/52/48) specimens, the dielectric ocnstant of 1236 and the polarization reversal time of 460[nm] were obtained and the breakdown of the film did not occur up to 1*10$^{10}$ cycles at the voltage of 7[V] by the bipolar acceleration. The remanent polarization and coercive field decreased with increasing the content of La in the range of 0-13[at%] and thin film of the PLZT(11/52/48) showed the value of 2.56[.mu.C/c $m^{2}$] and 21.1[kV/cm], respectively.ly.y.

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Effect of Trunk Stability Exercises with Stabilizing Reversal and Rhythmic Stabilization of PNF for Muscle Strength and Balance Ability in Stroke Patients (PNF의 안정적 반전과 율동적 안정화 기법을 이용한 체간 안정화 훈련이 뇌졸중 환자의 체간 근력과 균형 능력에 미치는 영향)

  • Kang, Tae-Woo;Ham, Kyu-Ha
    • PNF and Movement
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    • v.12 no.2
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    • pp.63-69
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    • 2014
  • Purpose: The purpose of this study was to investigate the effect that trunk stability exercises with stabilizing reversal and rhythmic stabilization of PNF have on trunk strength and balance ability in stroke patients. Methods: This study included 20 stroke patients who performed trunk stability exercises combined with stabilizing reversal and rhythmic stabilization of PNF. The exercise program consisted of 30-minute sessions per week for six weeks. Trunk strength (BTE, Primus RS) and balance ability (Berg Balance Scale) were evaluated before and after training. All data were analyzed using SPSS 18.0 software. Results: Significant differences were observed the both groups for truck strength and balance ability. The results of the study were as follows: trunk strength was significantly increased in both groups (p<.05) and it was also found to be significant between groups after the intervention (p<.05). Balance ability was significantly increased in both groups (p<.05) and it was also found to be significant between the groups after intervention (p<.05). Conclusion: Trunk stability exercises with stabilizing reversal and rhythmic stabilization of PNF are effective for improving trunk strength and balance ability in stroke patients. For stroke patients, trunk stability exercises with PNF are very useful and effective and they areeffectiveinclinicalpractice.

An analysis on developing process and problem of vocational education in China curriculum - based on vocational school- (중국 직업교육의 현황과 문제 - 직업 고등학교를 중심으로-)

  • Li, Zhangpei;Lee, Kwangwoo
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.8 no.6
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    • pp.475-483
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    • 2018
  • The purpose of this study to understand the vocational education of China and to analyze the developing process of vocational education in China. Recently, the major countries of the world of modern society has its government leaders is how much to foster creativity and the rise and fall depending on whether they really value is determined claims. There are 1327 Tertiary Vocational Colleges, with 10 million students in 2015. Together with 14million secondary vocational education students, China owns the largest scale of vocational education in the world. China has not fully established a modern market. Under the economy, the enterprise was the administrative adjunct of the state, and the enterprise was the social and political production function, and the political ethics prevailed that ethics. Literature review and historial approach were utilized as the methodology for this study. The system of vocational education in China is composed of elementary, secondary, and higher stage. The vocational education in China has been developed flexibly along with the social change while keeping the main philosophy of Chinese socialism. The main factors to bring about the change of vocational education in China is, political and philosophical, economical change.

Modelling of Principal Stress Rotation in Ko Consolidated Clay (Ko-압밀점토지반속 주응력회전 현상의 모형화)

  • Hong, Won-Pyo;Kim, Tae-Hyeong;Lee, Jae-Ho
    • Geotechnical Engineering
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    • v.13 no.1
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    • pp.35-46
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    • 1997
  • The isotropic single-hardening constitutive model has been applied to predict the behavior of soils during reorientation of principal stresses in the field. The predicted response by the model agrees well with the measured behavior for a series of torsion shear tests performed on hollow cylinder specimens of Ko consoildated clay along various stress -paths. This indicates that the soil behavior during reorientation of principal stresses can be predicted by using the model with application of simple informations given by isotropic compression tests and conventional consolidated-undxained triaxial compression tests. Isotropic elasto-plastic soil behavior has been served during primary loading from both the torsion shear tests and the predictions by the model. However, the directions of maj or principal strain increment given by the model have not coincided with the directions for tests during stress reversal, such as unloading and reloading, within isotropic yield surface for Ko consolidated stress. This indicates that kinematic hardening model instead of isotropic hardening model should be developed to predict the soil behavior during stress reversal. The experimental strain increment vectors in the work-space have been compared with the directions expected for associated and nonassociated flow rules.

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Synthesis of Borosilicate Zeotypes by Steam-assisted Conversion Method (수증기 쪼임법에 의한 제올라이트형 보로실리케이트 제조방법)

  • Mansour, R.;Lafjah, M.;Djafri, F.;Bengueddach, A.
    • Journal of the Korean Chemical Society
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    • v.51 no.2
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    • pp.178-185
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    • 2007
  • Intermediate pentasil borosilicate zeolite-like materials have been crystallized by a novel method named steam-assisted conversion, which involves vapor-phase transport of water. Indeed, amorphous powders obtained by drying Na2O.SiO2.B2O3.TBA2O gels of various compositions using different boron sources are transformed into crystalline borosilicate zeolite belonging to pentasil family structure by contact with vapors of water under hydrothermal conditions. Using a variant of this method, a new material which has an intermediate structure of MFI/MEL in the ratio 90:10 was crystallized. The results show that steam and sufficiently high pH in the reacting hydrous solid are necessary for the crystallization to proceed. Characterization of the products shows some specific structural aspects which may have its unique catalytic properties. X-ray diffraction patterns of these microporous crystalline borosilicates are subjected to investigation, then, it is shown that the product structure has good crystallinity and is interpreted in terms of regular stacking of pentasil layers correlated by inversion centers (MFI structure) but interrupted by faults consisting of mirror-related layers (MEL structure). The products are also characterized by nitrogen adsorption at 77 K that shows higher microporous volume (0.160 cc/g) than that of pure MFI phase (0.119 cc/g). The obtained materials revealed high surface area (~600 m2/g). The infrared spectrum reveals the presence of an absorption band at 900.75 cm-1 indicating the incorporation of boron in tetrahedral sites in the silicate matrix of the crystalline phase.