• 제목/요약/키워드: External mixture

검색결과 173건 처리시간 0.025초

Intelligent Phase Plane Switching Control of Pneumatic Artificial Muscle Manipulators with Magneto-Rheological Brake

  • Thanh, Tu Diep Cong;Ahn, Kyoung-Kwan
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1983-1989
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    • 2005
  • Industrial robots are powerful, extremely accurate multi-jointed systems, but they are heavy and highly rigid because of their mechanical structure and motorization. Therefore, sharing the robot working space with its environment is problematic. A novel pneumatic artificial muscle actuator (PAM actuator) has been regarded during the recent decades as an interesting alternative to hydraulic and electric actuators. Its main advantages are high strength and high power/weight ratio, low cost, compactness, ease of maintenance, cleanliness, readily available and cheap power source, inherent safety and mobility assistance to humans performing tasks. The PAM is undoubtedly the most promising artificial muscle for the actuation of new types of industrial robots such as Rubber Actuator and PAM manipulators. However, some limitations still exist, such as the air compressibility and the lack of damping ability of the actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. In addition, the nonlinearities in the PAM manipulator still limit the controllability. Therefore, it is not easy to realize motion with high accuracy and high speed and with respect to various external inertia loads in order to realize a human-friendly therapy robot To overcome these problems a novel controller, which harmonizes a phase plane switching control method with conventional PID controller and the adaptabilities of neural network, is newly proposed. In order to realize satisfactory control performance a variable damper - Magneto-Rheological Brake (MRB) is equipped to the joint of the manipulator. Superb mixture of conventional PID controller and a phase plane switching control using neural network brings us a novel controller. This proposed controller is appropriate for a kind of plants with nonlinearity uncertainties and disturbances. The experiments were carried out in practical PAM manipulator and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with phase plane switching control using neural network and without regard for the changes of external inertia loads.

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Effect of Combined Refining Plates with Different Bar Angles on Paper Properties during Mixed Pulp Refining

  • GUO, Xiya;DONG, Jixian;LIU, Huan;DUAN, Chuanwu;YANG, Ruifan;QI, Kai
    • Journal of the Korean Wood Science and Technology
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    • 제48권5호
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    • pp.581-590
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    • 2020
  • Pulp refining is the major way to alter the properties of fibers and formed paper. Different combinations of the bar profile of the rotor and stator during low consistency refining processes directly affect the properties of the paper. In this study, a mixture of softwood and hardwood pulp was refined by varying the bar angle of the stator while that of the rotor is fixed at 0º. The pulp samples were collected at different refining times. Then, the pulp and paper properties, such as beating degree, fiber external fibrillation, and tensile and tear indexes were measured to explore the effects of the combined refining plates at different bar angles on paper properties. The results of the experiment show that the combined refining plate of 0º and 5º recorded the most significant improvement in the pulp beating degree and fiber external fibrillation. This consequently increased the fiber bonding area, which in turn, improved both the tensile and the tear indexes of the paper. Also, the influence of the combined refining plates with a larger bar angle on the paper properties was weaker compared to that of smaller angles. This study not only provides ideas for the bar profile design but also improves the optimal selection of refining plates.

레이저 흡수 분광법을 이용한 He-Ne-Xe 상종가스의 외부전곡 램프의 $1s_4$ 공명준위와 $1s_5$ 준안정준위의 제논 원자 밀도에 대한 연구 (Laser absorption spectroscopy of ternary gas mixture of He-Ne-Xe in External Electrode Fluorescent Lamp (EEFL))

  • 정세훈;오필용;이준호;조광섭;최은하
    • 한국진공학회지
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    • 제15권6호
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    • pp.576-580
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    • 2006
  • 본 논문에서는 수은 램프를 대체하기 위하여 제논 기체를 사용한 무수은 램프를 제작하여 제논 여기종 밀도에 대한 연구를 진행하였다. 진공자외선을 방사할 수 있는 $1s_4$ 공명준위의 제논 원자 밀도와 $1s_5$ 준안정준위의 제논 원자 밀도를 레이저 흡수 분광법을 사용하여 다양한 기체조건 및 방전전류에 따라서 측정하였다. 우리는 주어진 압력에서 방전전류에 따른 $1s_4$ 공명준위의 제논 원자 밀도와 $1s_5$ 준안정준위의 제논 원자 밀도를 측정하였으며 이러한 기본적인 방전 특성의 이해는 EEFL뿐만 아니라 플라스마 디스플레이에서도 발광 효율을 높이는데 매우 큰 기여를 할 것이다.

업사이클링 패션브랜드에 나타난 소재특성 연구 (제2보) -업사이클링 소재를 이용한 패션가방 제작- (A Study on the Characteristics of Material in the Foreign Up-cycling Fashion Brands (Part II) -Fashion Bag Making Using Up-cycling Fashion Brand Material-)

  • 이다혜;정경희;배수정
    • 한국의류학회지
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    • 제43권1호
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    • pp.95-111
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    • 2019
  • This study is the 2nd report following "A Study on the Characteristics of Material in the Korean Up-cycling Fashion Brands (Part I)" that handled the development of upcycling props using the characteristics of upcycling material. The 2nd report analyzed product types and materials focusing on 21 foreign upcycling fashion brands. It analyzed the characteristics of upcycling fashion materials using the case analysis of coffee bean bag and waste denim based on external characteristics and internal characteristics. We then classified the external characteristics into environment/economic feasibility and availability/mixture and the internal characteristics into historicality/story and originality/scarcity. Five bags were designed and produced for the actual commercialization of fashion products based on such characteristics of materials, with the use of coffee bean bags and waste denim as upcycling materials. This study is differentiated from existing research by its suggestions for the utilization of fashion product upcycling coffee bean bags and waste denim. Also, upcycling fashion products could be competitive products in eco-friendliness and originality that can be a driving force for the sustainable development of fashion industry through the differentiation of existing fashion products.

각종 요인이 물속의 Diastase 활성에 미치는 영향 (Effect of External Factors on Diastase Activity in Water)

  • 윤복상;현호섭;백남원
    • Journal of Preventive Medicine and Public Health
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    • 제7권1호
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    • pp.107-113
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    • 1974
  • 위생공학에서 하수나 공장폐수를 처리할 때 이용하는 생물학적 처리과정은 미생물에서 생성되는 효소에 의하여 이루어 진다. 본 연구에서는 diastase의 활성에 대하여 수소이온 농도, 온도, 기질 농도 및 방해물질 등 여러가지 요인이 미치는 영향을 실험적으로 관찰하여 다음과 같은 결론을 얻었다. (1) diastase의 활성도는 pH $4.0{\sim}7.0$의 범위가 적당하였고 최적치는 pH 5.0이었다. (2) diastase의 활성도는 $30^{\circ}C{\sim}50^{\circ}C$ 높았으며 최적온도는 $40^{\circ}C$였다. (3) 기질농도의 영향을 보면 녹말농도 $750{\mu}g/ml$까지는 diastase의 활성도가 급격히 증가하였고, 그 이후에는 한정속도를 나타냈다. Michaelis 방정식을 적용시켜 보면 한정속도는 $415{\mu}g/ml$ starch removed/ml of reaction mixture/min였고 Michaelis 상수는 $340{\mu}g/ml$였다. (4) 방해물질의 영향을 보면 NaCl 농도 1.0%, $HgCl_2$ 농도 0.001%에서 diastase의 활성은 완전히 억제되었다.

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팥과 녹두 잡초방제체계(雜草防除體系) 수립(樹立)을 위한 제초제(除草劑) 병발(迸拔)에 관한 연구 (Selection of Appropriate Herbicides for Establishment of Weed Control System in Adzukibean and Mungbean)

  • 홍은희;이영호;김석동;황영현;문윤호
    • 한국잡초학회지
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    • 제3권2호
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    • pp.199-207
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    • 1983
  • 팔 녹두에 적합(適合)한 제초제선발(除草劑選拔)을 위하여 1980~1983 년(年)의 4 개년(個年)에 걸쳐 작물시험장(作物試驗場)에서 포장시험(圃場試驗)과 pot 시험(試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 제초제(除草劑)에 대한 내성(耐性)은 콩이 가장 컸으며, 녹두, 팥의 순서(順序)이다. 2. 출아전처리제(出芽前處理劑)로서 alachlor와 그외 7 종(種)의 제초제(除草劑)에 대한 약해(藥害)를 검정(檢定)한 결과(結果) 약해(藥害)를 비교적(比較的) 덜 일으키는 제초제(除草劑)는 팥에서 chloramben, linuron, metribuzin 등(等)이며, 녹두에 서 alachlor. butachlor 등(等)이었다. 3. 출아후처리제(出芽後處理劑)로서 팔, 녹두에 외관상(外觀上) 약해(藥害)를 일으키지 않는 제초제(除草劑)는 alloxydim, Dowco 453, fluazifop 등(等)이었다. 4. 출아전처리제(出芽前處理劑)로서 terbutryn 150g, a.i./l0a 처리(處理)가 팔과 녹두에 대한 잡초방제효과(雜草防除効果)가 가장 양호(良好) 하였으나 약해(藥害)의 우려가 있으며, 출아후처리제(出芽後處理劑)로서 acifluorfen 30g. a.i./10a 처리시(處理時) 잡초방제효과(雜草防除効果)가 가장 양호(良好)하였고 약해(藥害)도 20일(日) 이내(以內)에 회복(回復)되어 수량(收量)에는 영향(影響)을 미치지 않았다. 5 제초제(除草劑) 단일처리(單一處理) 보다는 혼합(混合) 및 조합처리시(組合處理時) 잡초방제효과(雜草防除効果)가 뚜렷하였으며 성분량(成分量)으로 10a당(當) 팥에서 linuron 50 g과 Dowco 453 l8g 또는 fluazifop 26g 조합처리(組合處理)가, 녹두에서 alachlor 131 g과 acifluorfen l5g 조합처리(組合處理)가 체초방제효과(體草防除效果)와 수량(收量)이 높았다.

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Effectiveness of the neutron-shield nanocomposites for a dual-purpose cask of Bushehr's Water-Water Energetic Reactor (VVER) 1000 nuclear-power-plant spent fuels

  • Rezaeian, Mahdi;Kamali, Jamshid;Ahmadi, Seyed Javad;Kiani, Mohammad Amin
    • Nuclear Engineering and Technology
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    • 제49권7호
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    • pp.1563-1570
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    • 2017
  • In order to perform dry interim storage and transportation of the spent-fuel assemblies of the Bushehr Nuclear Power Plant, dual-purpose casks can be utilized. The effectiveness of different neutron-shield materials for the dual-purpose cask was analyzed through a set of calculations carried out using the Monte Carlo N-Particle (MCNP) code. The dose rate for the dual-purpose cask utilizing the recently developed materials of $epoxy/clay/B_4C$ and $epoxy/clay/B_4C/carbon$ fiber was less than the allowable radiation level of 2 mSv/h at any point and 0.1 mSv/h at 2 m from the external surface of the cask. By utilization of $epoxy/clay/B_4C$ instead of an ethylene glycol/water mixture, the dose rates on the side surface of the cask due to neutron sources and consequent secondary gamma rays will be reduced by 17.5% and 10%, respectively. The overall dose rate in this case will be reduced by 11%.

MoO3 침출공정 폐액으로부터 동분말의 회수기술 (Recovery of Copper Powder from MoO3 Leaching Solution)

  • 홍현선;정항철;김건홍;공만식
    • 한국분말재료학회지
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    • 제16권5호
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    • pp.351-357
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    • 2009
  • A two-step recovery method was developed to produce copper powders from copper chloride waste solution as byproducts of MoO$_3$ leaching process. The first step consisted of replacing noble copper ions with external Fe$^{3+}$ ions which were formed by dissolving iron scraps in the copper chloride waste solution. The replaced copper ions were subsequently precipitated as copper powders. The second step was cementation of entire solution mixture to separate (pure) copper powders from aqueous solution of iron chloride. Cementation process variables of temperature, time, and added amount of iron scraps were optimized by using design of experiment method and individual effects on yield and efficiency of copper powder recovery were investigated. Copper powders thus obtained from cementation process were further characterized using various analytical tools such as XRD, SEM-EDS and laser diffraction and scattering methods.Cementation process necessitated further purification of recovered copper powders and centrifugal separation method was employed, which successfully yielded copper powders of more than 99% purity and average 1$\sim$2$\mu$m in size.

일사량 감응 및 관수공급이 가능한 연소형 CO2 발생기 통합 제어시스템의 설계 (Design of Integrated Control System for Combustion Type CO2 Generator with Solar Radiation Sensitiveness and Irrigation Supply)

  • 김응곤
    • 한국전자통신학회논문지
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    • 제13권3호
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    • pp.617-622
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    • 2018
  • 시설원예 하우스 내부의 공기 밀폐나 유동상태에 직접적인 영향을 주는 송풍기, 측창 개폐기의 동시제어는 $CO_2$ 농도 관리에 필수적이다. 현재 농업인구 감소에 따른 개인당 경작면적 증가로 자동화 시스템과 통합제어의 요구가 꾸준히 증가하고 있는 실정이다. 본 논문에서는 $CO_2$발생기의 연료 및 연소공기 혼합비(공연비), 내 외부 환경에 따른 $CO_2$ 공급량의 제어와 $CO_2$ 공급에 있어 중요한 변수인 측정 개폐기와 같은 기존 설치기기를 동시에 제어할 수 있는 통합 제어시스템을 제안한다.

현대 패션에 표현된 신체장식의 혼성모방 분석 (An Analysis of Pastiche in Body Ornamentation of Modern Fashion)

  • 손향미;박길순
    • 한국의류학회지
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    • 제27권8호
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    • pp.981-991
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    • 2003
  • The purpose of this study is to observe the cultural phenomenon in modern society from the point of view of pastiche, analyze the characteristics of pastiche, create a framework for studying modem fashion and body ornamentation, one of the facts of cultural phenomenon and, based on these aspects, will observe the pastiche phase, which occurred in body ornamentation of modem fashion in the late 1990's Collections. The characteristics of pastiche is that it transcends meaning, alters the usage of objects, raises the beauty of alienation and pursues temporariness. Observing pastiche, according to its definition and characteristics, as it appears in body ornamentation of modem fashion, the results were as follows: First of all, in terms of transcending meaning, body ornamentation of modern fashion is a mixture of all past styles. Secondly, use of objects in body ornamentation of fashion has shown the use of things which have never been used in accessorizing before, such as birdcages, bones of body, castle. Third, in terms of the raising of the beauty of alienation, accessories from countries, which were not high interest groups in the past, such as piercing, scar, corpulent, are being used as high-fashion accessories in body ornamentation of modern fashion. Fourth, in terms of the pursuit of temporariness, external ornamentation in body ornamentation of modern fashion is seen as permanent changes to the outer body, such as tattoos, piercings, hair color and the more temporary changes, such as coloring.