• Title/Summary/Keyword: Property Variation

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A Study on the Quasi-Sliding Mode Condition in Discrete Time Variable Structure Systems (아산시간 가변구조 시스템에서 준 슬라이딩 모드 조건에 관한 연구)

  • 이강웅;최계근
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.8
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    • pp.899-905
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    • 1988
  • In this paper, we suggest a new quasi-sliding mode condition with a wighting factor which guarantees all the states to reach switching planes and improves the convergence of the state trajectories. The result of computer simulation shows that by the suitable selection of a weighting factor, all the state trajectories reach switching planes and enter the sliding mode having the property of the insensitivity to parameter variation and disturbances.

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Stochastic Response Analysis of Transmission Tower Subjected to Young's Modulus Variation (송전철탑의 탄성계수의 변이에 따른 확률적 응답변이도)

  • 동원영;정영수
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.207-215
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    • 1993
  • With the aid of finite element method, this paper deals with the problem of structural response variability of transmission tower subjected to the spatial variability of material properties, Young's modulus herein. The spatial variability of material property are modeled as two-dimensional stochastic field which has an isotropic auto-correlation function. Response variability has been computed based on two numerical techniques, such as the Neumann expansion method in conjunction with the Monte Carlo simulation method. The results by these numerical methods are compared with those by the deterministic approach.

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Study on the Driving property of planar gate light source (전계방출 광원용 플라나 게이트의 구동 특성 연구)

  • Kim, Kwang-Bok;Yang, Dong-Wook;Kim, Tae-Hyeon;Kim, Dae-Jun
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.05a
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    • pp.148-150
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    • 2008
  • In this paper, we report the improved driving methode using planar-gate for field emission light source. Due to the cold cathode in field emission device, it has advantage for driving system in terms of high speed pulse driving with narrow duty ratio. This paper shows that our driving method offers the stable and reliable driving system without rapid electric field variation for field emission light source.

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An Experimental Study on the Property Transformation for High-Heated Inorganic Insulation (고온수열된 무기질단열재의 물성변화에 관한 실험적 연구)

  • 김봉주;김태용;오창희
    • Fire Science and Engineering
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    • v.5 no.1
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    • pp.29-36
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    • 1991
  • The purpose of this study is to understand the variations of the properties of matters according to the heated temperature of inorganic insulation. As a result, form the variation of heat conductivity and maintaining from of insulation, the range of reusable heated temperature of inorganic insulation is as follows. Glass wool : $400^{\circ}C$, Rock wool : $600^{\circ}C$, Perlite : $800^{\circ}C$.

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Characterization of Ag Pastes with solid contents variation (Solid Contents 에 따른 Ag Paste 의 특성 변화)

  • 조현민;유명재;이우성;양형국;박종철
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.11a
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    • pp.169-172
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    • 2002
  • Silver pastes for inner conductor in the Low Temperature Co-fired Ceramics (LTCC) are composed of silver powder, binder, solvent and additives. The composition of the chemicals have influence on rheology, printability, shrinkage rate, etc. In this study, commercial Ag pastes and Ag pastes made in KETI were investigated to find the relationship between characteristics of Ag paste and solid contents. Ag pastes with 68~90 wt% Solid Contents were tested. Substrate/paste matching property and conductivity of the conductor lines showed large dependence on solid contents of Ag paste.

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Regional Variation of the Intellectual Property Rights between Local Governments (지식재산권 실적의 지역별 변화)

  • Kim, Jaehee;Kim, Yongsik
    • Proceedings of the Korea Contents Association Conference
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    • 2018.05a
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    • pp.227-228
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    • 2018
  • 앞으로의 정보화시대에는 생산능력 자체 보다 이와 관련한 지적재산을 얼마나 많이 확보하고 있느냐가 중요하다. 이에 본 연구에서는 각 지자체가 확보하는 지적재산권의 현황을 분석하고, 지역별 차이에 대해 분석해 보았다. 그리고 이를 통해 지적재산 분야에서의 지역 균형 발전을 위한 시사점을 도출하고자 하였다.

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Preparation of Fe2O3 Coated on Mica for Infrared Reflectance Red Pigment and Thermal Property of Its Isolation-Heat Paint (Fe2O3가 코팅된 판상 mica의 적외선 반사용 적색안료 제조 및 차열도료의 열특성)

  • Lee, Hyun Jin;Kim, Dae Sung;Lee, Seung-Ho;Lim, Hyung Mi;Choi, Byung-Ki;Kang, Kwang-Jung;Jeong, Jae Il;Cho, Kum-Sung
    • Korean Journal of Materials Research
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    • v.25 no.2
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    • pp.61-67
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    • 2015
  • $Fe_2O_3$ coated plate mica($Fe_2O_3$/mica) for infrared reflectance red pigment was prepared under hydrothermal treatment. $Fe_2O_3$ was perfectly coated on mica via the difference of surface charge between $Fe_2O_3$ and mica particles at pH 3. $Fe_2O_3$/mica was then calcined at $800^{\circ}C$ to stabilize the coated layer on mica. The infrared(IR) reflectance pigments were characterized by X-ray diffraction, FE-SEM, zeta potential, and a UV-Vis-NIR spectrophotometer. In particular, the CIE color coordinate and IR reflectance properties of $Fe_2O_3$/mica pigments were investigated in relation to the thickness variation of the $Fe_2O_3$ layer coated on mica of various lateral sizes. The isolation-heat red paints containing the pigments were prepared and optimized with a thinner, settling agent, and dispersant. Then, the films were made. The thermal property of isolation-heat on these films was observed through the relationship of the IR reflectance value, which was based on the variation of the $Fe_2O_3$ layer's thickness coated on mica and mica's lateral size as IR reflectance pigment. With an increase in IR reflectance on these films, the thermal property of isolation-heat was effectively enhanced.

Study on the Conditioning of Brown Rice (I) -Property variation and predicted model of brown rice after Conditioning- (현미 조질에 관한 연구 (I) -조질 후 현미의 물성 변화와 예측모델-)

  • 한충수;연광석;강태환;전홍영;고학균
    • Journal of Biosystems Engineering
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    • v.26 no.1
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    • pp.39-46
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    • 2001
  • This research conducted to investigate the variation of the moisture content, crack ratio, and hardness of the whole and cracked brown rice after conditioning at the initial moisture content of 13, 14, and 15% with time lapse. The conditioning was conducted by increasing the moisture content of the sample to 0.4 and 0.8%. For basic information and conditioning characteristics for the development of a conditioning machine for the brown rice, predicted models of above three properties were developed using a nonlinear regression analysis of SAS with Gauss-Newton, Gradient, and DUD methods. Results of this research could be summarized as follows. 1. No moisture variation occurred after 0.5 hour conditioning. 2. The increasement of the crack ratio was 7.6 and 17.5% with the sample increased the moisture content of 0.4 and 0.8%, respectively, after 8 hours conditioning. 3. The hardness of the conditioned whole grain of the brown rice decreased 0.82 and 1,000kg$\_$f/ with the sample increased moisture content 0.4 and 0.8%, respectively, after 8 hours conditioning with respect to the non-conditioned sample. 4. The hardness of the conditioned cracked grain of the brown rice decreased 0.54 and 0.81kg$\_$f/ with the sample increased moisture content 0.4 and 0.8%, respectively, after 8 hours conditioning with respect to the non-conditioned sample. The hardness of the broken grain was about 0.81∼1.88kg$\_$f/ lower than whole grain. 5. The moisture content variation, increasing rate of the crack ratio, and hardness of the cracked and whole grain was predicted as a negative exponential function. 6. Each predicted model with the nonlinear regression analysis, which was very accurate and had a very small amount of sum of square of error between experimental value and predicted value, which could be used for predicting the physical variation after conditioning.

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