• Title/Summary/Keyword: 정방

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Effect of Ring Spinning Tension on the Properties of Cotton Spun Yarn (링 정방장력이 면방적사 물성에 미치는 영향)

  • 김규호;박민규;양중식
    • Proceedings of the Korean Fiber Society Conference
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    • 2002.04a
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    • pp.73-76
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    • 2002
  • 최근 링 정방기의 생산속도 증가로 인해 사절 및 사물성에 큰 영향을 미치는 정방장력의 중요성이 더욱 커지고 있다. 링 정방장력은 스핀들 회전수, 트래블러 중량, 링직경, 콥 직경 등과 같은 공정인자와 링 레일 상하운동에 따른 벌룬 높이, 얀 가이드에서의 실 굴절각도, 콥의 권취 반경 및 공기저항 등에 의해서도 영향을 받게 된다[1]. 이와 관련하여 링 정방장력 해석[2], 정방 공정인자가 정방장력에 미치는 영향[3] 및 정방 공정인자가 방적사 물성에 미치는 영향[4] 등의 연구가 많이 이루어져 왔다. (중략)

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오픈 앤드 로우터 방적사의 섬유 이주거동에 관한 연구 (I)

  • Kim, Young-Ryul;Heo, Yu;Ryu, Woon-Young
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.04a
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    • pp.160-165
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    • 1998
  • 방적사의 물성은 실을 구성하는 섬유의 물성 뿐만 아니라 실의 구조에 따라 달라지며 실의 구조는 섬유의 배열상태와 기하학적 배치구조에 따라 결정된다. 지난 수십년 동안 재래식 시스템으로 방적된 단섬유 방적사의 구조에 대하여 폭넓은 연구가 이루어져 왔으며 링방적법에 비해 생산성을 높이기 위하여, 오픈엔드 정방, 에어젯 정방, 셀프 트위스트 정방 및 랩 정방등 많은 혁신 방적기술이 개발되었다.(중략)

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Structural Study of Interface Layers in Tetragonal-HfO2/Si using Density Functional Theory (범 밀도함수론을 이용한 정방정계-HfO2/Si의 계면 층 구조 연구)

  • Kim, D.H.;Seo, H.I.;Kim, Y.C.
    • Journal of the Korean Vacuum Society
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    • v.18 no.1
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    • pp.9-14
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    • 2009
  • We calculated tetragonal-$HfO_2$/Si superstructures using density functional theory. When a and b-axes of cubic-$HfO_2$ were increased to be matched with those of Si for epitaxy contact, c-axis was decreased by 2%. Eight models of interface layers were produced by choosing different terminating layers of tetragonal-$HfO_2$ and Si substrate at the interface. It was found that tetragonal-$HfO_2$ $(004)_{1/4}$/Si $(004)_{3/4}$ superstructure was the most favorable and tetragonal-$HfO_2$ (004)$_{1/4}$/Si (002) superstructure was the most unfavorable. In tetragonal-$HfO_2$ $(004)_{1/4}$/Si (002) superstructure, there were two oxygen vacancies in tetragonal-$HfO_2$ as two oxygen atoms were moved to Si substrate located at the interface.

회전링의 동적 안정성을 고려한 링 형상 최적화 연구

  • Jang, Jae-Jun;Jang, Seung-Ho;Heo, Yu
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.04a
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    • pp.173-178
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    • 1998
  • 섬유산업의 발달로 정방공정이 자동화, 고속화되고 있으며 국제적 경쟁이 치열하게 전개됨에 따라 방적공정에서의 생산성이 매우 중요해 졌다. 링 정방법은 링위를 회전하는 traveller에 의한 꼬임부여와 중앙에 위치한 spindle의 회전에 의하여 권취가 이루어진다는 간단한 작동 원리를 바탕으로 하고 있으며 현재 개발된 정방공법중 생산 유연성이 가장 크고 제품의 물성이 우수하여 널리 이용되고 있는 공법이다.(중략)

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링, 로우터, 와동 방적사의 물리적 특성에 관한 연구

  • 박철민;정성훈
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.331-335
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    • 1998
  • 방적이란 섬유에서 실(사)로의 변환 과정이며 여기에서 정방 공정이 방적공정에서 70%정도의 비용을 초래한다. 섬유관련업자들은 이러한 섬유에서 실(사)로의 변환 과정을 고 생산성에 맞추어 새로운 방적법의 개발 및 개량에 지속적인 연구를 하고있다. 근래에 보급된 에어젯 정방기는 섬유업자들로 하여금 고속의 생산성을 기대할 수 있도록 하였다. (중략)

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Quality Change in Kimchi made of Spring Kimchi Cabbage during Fermentation under Different Storage Conditions (저장조건을 달리한 봄배추로 제조한 김치의 숙성 중 품질 변화)

  • Bang, Hye-Yeol;Cho, Sun-Duk;Kim, Byeong-Sam;Kim, Gun-Hee
    • The Korean Journal of Food And Nutrition
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    • v.30 no.2
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    • pp.378-387
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    • 2017
  • To stabilize the supply of kimchi by extending the storage period of spring kimchi cabbage, this study manufactured kimchi from spring kimchi cabbage under varying storage conditions and periods, and analyzed their quality and sensory characteristics following the maturing period. Trimming loss was lowest in the group of plasma+reverse direction+predrying+HDPE film processing. The salting yield of spring kimchi cabbage stored for 12 weeks was lower than that of spring kimchi cabbage stored for 6 weeks, and the kimchi yield was low in the pre-treatment group of spring kimchi cabbage stored for 12 weeks. The firmness was slightly different according to the storage period from one month of maturation. From the perspective of pH and acidity, the maturation in the reverse direction+pre-drying+HDPE film processing group was slower than that in the normal group (<0.05). In the sensory evaluation, the preference was increased in the low temperature storage processing group as the maturation period was increased (<0.05).

Development of Forward chaining inference engine SMART-F using Rete Algorithm in the Semantic Web (차세대 웹 환경에서의 Rete Algorithm을 이용한 정방향 추론엔진 SMART - F 개발)

  • Jeong, Kyun-Beom;Hong, June-Seok;Kim, Woo-Ju;Lee, Myung-Jin;Park, Ji-Hyoung;Song, Yong-Uk
    • Journal of Intelligence and Information Systems
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    • v.13 no.3
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    • pp.17-29
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    • 2007
  • Inference engine that performs the brain of software agent in next generation's web with various standards based on standard language of the web, XML has to understand SWRL (Semantic Web Rule Language) that is a language to express the rule in the Semantic Web. In this research, we want to develop a forward inference engine, SMART-F (SeMantic web Agent Reasoning Tools-Forward chaining inference engine) that uses SWRL as a rule express method, and OWL as a fact express method. In the traditional inference field, the Rete algorithm that improves effectiveness of forward rule inference by converting if-then rules to network structure is often used for forward inference. To apply this to the Semantic Web, we analyze the required functions for the SWRL-based forward inference, and design the forward inference algorithm that reflects required functions of next generation's Semantic Web deducted by Rete algorithm. And then, to secure each platform's independence and portability in the ubiquitous environment and overcome the gap of performance, we developed management tool of fact and rule base and forward inference engine. This is compatible with fact and rule base of SMART-B that was developed. So, this maximizes a practical use of knowledge in the next generation's Web environment.

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Robust Autopilot Design for Nonsquare Flight Systems (비정방 비행 시스템에 대한 강인한 자동조종장치 설계)

  • 김종식;정성훈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1123-1131
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    • 1993
  • A robust controller is proposed to design a flight autopilot for lateral motion control. The control system has two control loops in order to meet the performance and to maintain the stability-robustness for a nonsquare flight system with uncertain aerodynamic variations and disturbance. One is designed via linear quadratic Gaussian with loop transfer recovery(LQG/LTR) design methodology for the inner loop. The other is designed via proportional controller design method for the outer loop. To show the effectiveness of this control system, it is compared with the LQG/LTR control system for a square flight system and is analyzed for the performance/stability-robustness to model uncertainties and disturbance via wind gusts. It is found that the proposed control system has good heading command-following performance under allowable sideslip angle in spite of model uncertainties and disturbance.