• 제목/요약/키워드: modified form

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섬유혼입 공법을 이용한 폴리머 시멘트 모르타르의 폭렬저감방안에 관한 실험적 연구 (An Experimental Study on Spalling Reduction Methode of Polymer Modified Cement Mortar Using Fiber Cocktail)

  • 김지훈;류동우
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 봄 학술논문 발표대회
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    • pp.96-97
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    • 2020
  • Polymer modified cement mortar (PCM) is commonly used as a repair material. However, in high-temperature environments such as fire, it is more likely to explode than cement mortar. The polymer is thermally decomposed at a high temperature to form a gas, and the gas remaining inside the structure increases the internal pressure to generate a burst. When an spalling occurs, the coating is peeled off and dropped, and high temperature is transmitted to the inside of the structure. In severe cases, even the reinforcing bar is exposed, which can lead to the collapse of the structural member due to severe loss of strength. In this study, in order to reduce spalling of PCM, a fiber mixing method was selected from the refractory method to find an appropriate blending ratio of fibers and polymers.

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총톤수 360톤급 어업지도선의 선형개선 및 횡요감소장치 성능에 관한 실험적 연구 (An Experimental Study on Hull Form Development and Anti-Rolling Tank Performance of G/T 360ton Class Fishery Patrol Ship)

  • 이귀주;좌순원;김경화
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2003년도 춘계학술대회 논문집
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    • pp.245-250
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    • 2003
  • Hull form development and Anti-rolling tank of G/T 360ton class fishery patrol ship was carried out in the CWC at Chosun university, cooperatively with WJFEL(The West Japan Fluid Engineering Laboratory). Same size of 15 knots class fishery patrol ship was selected as a parent form(Model number: CU-015), and modified fore and after body hull form under the slightly lengthened to be suitable for the operation at 20 knots. This paper investigated for a rolling performance and an effective using method when fishery patrol ship was equipped with anti-rolling tank. On several occasions of rolling test was made reference to design data of a similar ship. Although the hull form was highly constrained in being limited to modification of a parent hull form, significant wave resistance improvement was made.

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순차적 설계기법에 의한 DWT 75,000 정유운반선의 선형설계 (Stepwise Hull Form Design of DWT 75,000 Product Oil Carrier)

  • 박연석;박세라;정요한;최정규;유재훈
    • 대한조선학회논문집
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    • 제53권6호
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    • pp.456-464
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    • 2016
  • To design the modified hull form with relatively unfavorable dimensions and constraints than the parent ship the stepwise design was applied. In each design step the resistance characteristics was estimated by numerical calculations using CFD programs as Wavis 1.4, Wavis 2.1 and Fluent 12.1. The wave profiles along hull surface by potential flow calculations were investigated to improve wave resistance by modifying the bow shapes. To improve the stern shapes with a point of viscous form resistance the pressure distributions on hull surface and the limiting streamlines are investigated by viscous flow calculations. The design objectives such as shortening the LBP, enlarging the propeller tip clearance, moving forward of the LCB location and increasing the displacement were applied by stepwise to develop the new hull form of DWT 75,000 product oil carrier. Finally a new hull form was developed without the resistance performance loss compared with the parent ship.

The Modified Hanbok Jeogori Pattern Development Using Virtual Dressing System - Based on Female Bodice Pattern -

  • Jeon, Seong Yeon;Wee, Hye Jung
    • 패션비즈니스
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    • 제21권6호
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    • pp.66-76
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    • 2017
  • This study used a virtual wearing system equipped with body shape data with a 3D scanner, based on a female basic bodice, to develop a modified Hanbok Jeogori with high fitness capabilities to provide basic data for the development of the modified Hanbok Jeogori pattern for the academic and industrial fields. In this study, the representative modified Hanbok design which most frequently appeared in broadcasting ads and on line was selected. The wearing test was conducted by six professionals, and three times wearing tests were implemented based on 17 evaluation items. The data for this study was processed statistically using SAS 9.0. We conducted, the F-test for significance verification, the Duncan-test for a post test, and a correlation analysis of Cronbach's alpha coefficient for a reliability test of dressing test results were implemented for each of the three tests. The pattern of the developed modified Hanbok Jeogori overcame the defects of the short length of the conventional modified hanbok, and could fix the length issue. The developed Hanbok pattern solved the overlapping problem of the shoulder, back neck point-sleeve length(Whajang), and armhole, displayed in a straight line from the Godae point of the previous modified Hanbok; it suggested the position of the Seop and neck line in the basic bodice. Based on this, the Seop width, Git form, Goreum and the width, length, and position of the string whose dimensions can differ in accordance with the trend can be applied in various forms.

개선된 보간 알고리즘을 이용한 $H^{\infty}$-최적화 ($H^{\infty}$-optimization using the modified interpolation algorithm)

  • 이태형;윤한오;박홍배
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.46-51
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    • 1991
  • An algorithm of finding a solution to an $H^{\infty}$-minimization problem is proposed, and the solution is obtained explicity in terms of closed-form. We construct an optimal controller subject to the interpolation constraints such that $H^{\infty}$-norm and the minimized value of transfer function matrix are equal.l.

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산부인과 환자의 의료기관에 대한 이미지와 서비스 질이 고객만족에 미치는 영향 (Effect of Images about Medical Organizations and the Quality of Medical Service on Customer Satisfaction in Obstetrics and Gynecology Patients)

  • 정남옥
    • 간호행정학회지
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    • 제11권1호
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    • pp.59-66
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    • 2005
  • Purpose: The purpose of this study was to identify the effects images about medical organizations and the quality of service on customer satisfaction of obs and gyn patients. Method: The subjects of this study were selected conveniently 220 women among obstetrics and gynecology outpatients( who visited H- doctor's office of the first medical organ, P- hospital of the second medical organization, Chospital of the third medical organization). The data were collected from August, 20th 2004 using structured questionaires which included modified form of SERVPERF and customer's satisfaction scale by oliver & swan(1989), and modified form of image scale by kang(1997). Results: Image of hospital(45.3%), visiting frequencies(9.3%), service provider (3.9%) and convenient use(1.2%) of the quality of medical service were significant predictors to explain customer's satisfaction. Conclusion: To increase customer's satisfaction of obs and gyn patients, it is required to developed strategies that improve image of hospital and the quality of service to service provider and convenient use of hospital.

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COSMIC RAY ACCELERATION AT COSMOLOGICAL SHOCKS

  • KANG HYESUNG;JONES T. W.
    • 천문학회지
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    • 제37권5호
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    • pp.405-412
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    • 2004
  • Cosmological shocks form as an inevitable consequence of gravitational collapse during the large scale structure formation and cosmic-rays (CRs) are known to be accelerated at collisionless shocks via diffusive shock acceleration (DSA). We have calculated the evolution of CR modified shocks for a wide range of shock Mach numbers and shock speeds through numerical simulations of DSA in 1D quasi-parallel plane shocks. The simulations include thermal leakage injection of seed CRs, as well as pre-existing, upstream CR populations. Bohm-like diffusion is assumed. We show that CR modified shocks evolve to time-asymptotic states by the time injected particles are accelerated to moderately relativistic energies (p/mc $\ge$ 1), and that two shocks with the same Mach number, but with different shock speeds, evolve qualitatively similarly when the results are presented in terms of a characteristic diffusion length and diffusion time. We find that $10^{-4} - 10^{-3}$ of the particles passed through the shock are accelerated to form the CR population, and the injection rate is higher for shocks with higher Mach number. The CR acceleration efficiency increases with shock Mach number, but it asymptotes to ${\~}50\%$ in high Mach number shocks, regardless of the injection rate and upstream CR pressure. On the other hand, in moderate strength shocks ($M_s {\le} 5$), the pre-existing CRs increase the overall CR energy. We conclude that the CR acceleration at cosmological shocks is efficient enough to lead to significant nonlinear modifications to the shock structures.

Chemically Modified Sepharose as Support for the Immobilization of Cholesterol Oxidase

  • Yang, Hailin;Chen, Yi;Xin, Yu;Zhang, Ling;Zhang, Yuran;Wang, Wu
    • Journal of Microbiology and Biotechnology
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    • 제23권9호
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    • pp.1212-1220
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    • 2013
  • Because the cholesterol oxidase from Brevibacterium sp. M201008 was not as stable as the free enzyme form, it had been covalently immobilized onto chemically modified Sepharose particles via N-ethyl-N'-3-dimethylaminopropyl carbodiimide. The optimum immobilization conditions were determined, and the immobilized enzyme activity obtained was 12.01 U/g Sepharose-ethylenediamine. The immobilization of the enzyme was characterized by Fourier transform infrared spectroscopy. The immobilized enzyme exhibited the maximal activity at $35^{\circ}C$ and pH 7.5, which was unchanged compared with the free form. After being repeatedly used 20 times, the immobilized enzyme retained more than 40.43% of its original activity. The immobilized enzyme showed better operational stability, including wider thermal and pH ranges, and retained 62.87% activity after 20 days of storage at $4^{\circ}C$, which was longer than the free enzyme.

Static analysis of cutout microstructures incorporating the microstructure and surface effects

  • Alazwari, Mashhour A.;Abdelrahman, Alaa A.;Wagih, Ahmed;Eltaher, Mohamed A.;Abd-El-Mottaleb, Hanaa E.
    • Steel and Composite Structures
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    • 제38권5호
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    • pp.583-597
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    • 2021
  • This article develops a nonclassical model to analyze bending response of squared perforated microbeams considering the coupled effect of microstructure and surface stress under different loading and boundary conditions, those are not be studied before. The corresponding material and geometrical characteristics of regularly squared perforated beams relative to fully filled beam are obtained analytically. The modified couple stress and the modified Gurtin-Murdoch surface elasticity models are adopted to incorporate the microstructure as well as the surface energy effects. The differential equations of equilibrium including the Poisson's effect are derived based on minimum potential energy. Exact closed form solution is obtained for bending behavior of the proposed model considering the classical and nonclassical boundary conditions for both uniformly distributed and concentrated loads. The proposed model is verified with results available in the literature. Influences of the microstructure length scale parameter, surface energy, beam thickness, boundary and loading conditions on the bending behavior of perforated microbeams are investigated. It is observed that microstructure and surface parameters are vital in investigation of the bending behavior of perforated microbeams. The obtained results are supportive for the design, analysis and manufacturing of perforated nanobeams that commonly used in nanoactuators, nanoswitches, MEMS and NEMS systems.

Inconel 738LC의 Pt Modified-pack Aluminizing 내산화 코팅의 산화저항성에 미치는 Palladium 완충층의 영향 (Effects of Palladium Buffer Layer on the Oxidation Resistance of Inconel 738LC Oxidation Resistant Coating Layer by Pt Modified-pack Aluminizing)

  • 한원규;최재웅;홍석준;황길호;강성군
    • 한국재료학회지
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    • 제15권4호
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    • pp.233-239
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    • 2005
  • In this study, the effects of Pd buffer layer on the oxidation resistance of Pt modified-pack aluminized Inconel 738LC, used for gas turbine, were investigated. Pd was electroplated on Inconel 738LC, and Pt was electroplated on the electroplated Pd surface. Thus, the thickness of electroplated Pt/Pd was $10\;{\mu}m$ and the atomic ratio of Pt : Pd was about 6 : 4. After Pt/Pd electroplating, Inconel 738LC was pack aluminized to form the oxidation resistant layer. To investigate the oxidation resistance of Pt/Pd modified-pack aluminized Inconel 738LC, iso-thermal oxidation and cyclic oxidation were performed. The iso-thermal oxdation and the cyclic oxidation data indicated that the Pt/Pd modified-pack aluminized Inconel 738LC was more oxidation resistant than the Pt modified-pack aluminized Inconel 738LC. It was thought that the difference of thermal expansion coefficient between Inconel 738LC and Pt was lowered by the Pd buffer layer.