• 제목/요약/키워드: working uniform

검색결과 214건 처리시간 0.023초

유체 시뮬레이션을 이용한 선형 마이크로웨이브 플라즈마의 특성 분석 (Characterization of Linear Microwave Plasma using the Fluid Simulation)

  • 서권상;한문기;김동현;이호준
    • 전기학회논문지
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    • 제64권4호
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    • pp.567-572
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    • 2015
  • Discharge characteristics of linear microwave plasma were investigated by using fluid simulation of 2D axis-symmetry based on finite elements method. The microwave power was 2.45 GHz TEM mode and transmitted through linear antenna. Resistive power and pressure were considered simulation variables and argon was used for working gas. A decrease of electron density along the quartz tube was observed in low power condition but relatively uniform plasmas were generated in chamber by increasing the resistive power. The electron temperature was highly detected near the surface of quartz tube because the electron was heated only dielectric surface. The power transmission efficiency decreased and characteristics of surface plasma were observed in high electron density condition.

Elliptical 함수, Legendre 다항식을 이용한 단층, 다전류 솔레노이드의 자장균일도 비교 (Comparison of Uniformity of Calculated-magnetic Field in a Single-layer Solenoid with Multi-current by Using Elliptical Function and Legendre Polynomials)

  • 정정효;박포규;김윤배
    • 한국자기학회지
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    • 제9권5호
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    • pp.227-233
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    • 1999
  • 단층 솔레노이드의 길이 1.02m, 평균방경 0.11497m, 단위길이당 권선수 1000turns/m에서 Eooiptical 함수와 Legendre 다항식, Biot-Savart 법칙을 이용하여 단층 솔레노이드에 다전류를 인가하여 중심부근에서 자장균일도를 향상시키는 계산방법, 자장분포도 및 반지름 변화에 따른 자장균일도의 차이를 구하였다. 단전류 방법의 경우 1$\times$10-8의 자장균일도 공간이 중심에서 0.1cm 미만이지만, 5-current 방법은 8cm 정도로 80배정도 확대됨을 알 수 있고, 단층 단전류를 사용한 솔레노이드와 비교하였을 때 길이가 0.16km인 경우와 같은 효과를 얻었다. 또한 각각의 계산방법에 대한 자장오차를 비교분석하였다.

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$WO_3$를 이용한 박막형 슈퍼캐패시터의 제작 및 특성 평가 (Fabrication and Characterization of Thin Film Supercapacitor using $WO_3$)

  • 신호철;신영화;임재홍;윤영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.575-578
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    • 2000
  • In this work, all solid-state thin film supercapacitor(TFSC) was fabricated using tungsten trioxide (WO$_3$) with a structure WO$_3$/LiPON/WO$_3$/Pt/TiO$_2$/Si (substrate). After TiO$_2$ was deposited on Si(100) wafer by d.c. reactive sputtering, the Pt current collector films were grown on TiO$_2$glue layer without breaking vacuum by d.c. sputtering. Fabrication conditions of WO$_3$ thin film were such that substrate temperature, working pressure, gas ratio of $O_2$/Ar and r.f. power were room temperature, 5 mTorr, 20% (O$_2$(8sccm)/Ar(32sccm)) and 200W, respectively. LiPON electrolyte film were grown on the WO$_3$ film using r.f. magnetron sputtering at room temperature. The XRD pattern of the as-deposited WO$_3$ thin film were shown no crystalline peak (amorphous). The SEM image of as-deposited WO$_3$ thin film showed that the surface is smooth and uniform. The capacitiy of as-fabricated TFSC was 0$\times$10$^{-2}$ F/$\textrm{cm}^2$-${\mu}{\textrm}{m}$.

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소프트 스탬핑 프린팅 장비 개발에 관한 연구 (A Study on the Development of Soft Stamping Printing Equipment)

  • 장남은;김남국;이윤섭;김용태;신관우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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    • pp.259-262
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    • 2009
  • Several universities in Korea are beginning studies related to soft stamping processes but since the studies are done with manual works thus systematic tests can't be performed due to difficulties in producing reproducible and repeatable fine patterns. Therefore, the phenomenon of destruction of the pattern forms of elastic polymers occurred during working because of inconsistent printing pressures and pinting time and there have been difficulties in maintaining flatness or producing uniform and fault-free fine structures in pinting large areas and also, there have been difficulties in multi-layered processes as patterns were changed by contacts in registering and errors in alignments. The purpose of development of this technology is to improve the process of soft lithography so that contacts between PDMS stamps and metal coated substrates in order to develop a stamp printing device that can not only shorten but also optimize processes, secure reproducibility and repeatability and is advantageous in printing large areas. Also, using this technology, this author is to develop equipment technologies and applied technologies for nano grade pattern printing processes with new concepts based on fine contact printing processes in order to apply them to diverse nano pattering processes.

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마스터장치의 회전강성을 고려한 공압인공근육의 원격조정 (Teleoperation of Pneumatic Artificial Muscles Based on Joint Stiffness of Master Device)

  • 김령현;강봉수
    • 대한기계학회논문집A
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    • 제37권12호
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    • pp.1521-1527
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    • 2013
  • 본 논문에서는 마스터 조정자인 인간의 근육강도과 관절변위를 측정하여 슬레이브장치가 외부환경에 맞는 작업능력을 발휘할 수 있는 마스터/슬레이브 원격조정시스템을 제안한다. 외골격형 기구부와 경량의 관성센서를 사용하여 마스터 착용자의 편리성을 높였으며 인간의 근육과 동일한 운동특성을 가진 공압인공근육으로 슬레이브 기구장치를 구성하여 운동의 모사능력을 향상시켰다. 실험을 통해서 단순히 마스터의 위치정보만 전달하는 원격조정에 비해서 제안된 마스터는 인간 조정자가 근력의 세기를 조절함으로써 슬레이브에 작용하는 가반하중의 변화에 관계없이 균일한 제어성능을 가질 수 있었다.

Application of Subirrigation Using Capillary Wick System to Pot Production

  • Lee, Chi-Won;So, In-Sup;Jeong, Sung-Woo;Huh, Moo-Ryong
    • 농업생명과학연구
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    • 제44권3호
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    • pp.7-14
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    • 2010
  • Alternative subirrigation way, capillary wick system (CWS) was tested to reduce labor cost, waste water, contamination of ground water, and use of fungicide compared to overhead irrigation system (OIS). CWS helped reduce remarkably the working hours for watering from 4 hours in OSI to just 5 minutes. Labor cost was saved 98% in CWS compared to OIS. By the physical characteristics of various growing media, 1 coconut coir+2 perlite (v/v) mixture was selected because it had an ideal distribution of three phase, e.g. 1 solid: 1 liquid: 2 gas phase. Medium mixture containing scoria had so high bulk and particle density to hurt root. In bark-containing medium, the liquid phase and the percent saturation of liquid phase with time elapsed was lower than that of other mixture. It meant that the mixture contained very low level of water. Application of CWS for cyclamen pot production played an important role in reducing the incident of fusarium wilt symptom from 18% in conventional over watering system to 4%. Cyclamen pot irrigated by capillary wick had shorter petiole and more leaves than those by overhead watering. As a result, this system was highly beneficial to get uniform pot products with high quality. It improved water and nutrient solution efficiency relative to conventional overhead irrigation system (OIS).

엔지니어링 플라스틱 소재별 보강뿔대 형상에 따른 산업용 안전모의 구조 최적화 (Structural Optimization of Industrial Safety Helmet According to Frame Shape using Engineering Plastic)

  • 박만호;이여울;이용문;박재하;강명창
    • 한국기계가공학회지
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    • 제18권3호
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    • pp.41-48
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    • 2019
  • The industrial safety helmets are personal protective equipment (PPE), used to protect the head against falls from a height. This study indicated the necessity of wearing a safety helmet while working at heights below 4 m, through analysis of fall accidents occurring in the industrial field. The stress, displacement, and strain of the safety helmet shell structure have been analyzed using the finite element method with various thicknesses, engineering plastics, and designs. It was preferred that the safety helmet shell structure had a reinforcement frame of uniform thickness in terms of increased impact strength and strain energy absorption rate. The thickness can be reduced to lighten the total weight for workers wearing safety helmets.

THE NEW TYPE BROAD BEAM ION SOURCES AND APPLICATIONS

  • You, D.W.;Feng, Y.C.;Wang, Y.;Kuang, Y.Z.
    • 한국진공학회지
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    • 제4권S2호
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    • pp.131-138
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    • 1995
  • The broad beam ion sources of hot filament plasma type have widely used for modifications of materials and thin films, and the new type intensive current broad beam metal ion source including reactive gaseous ion beams is needed for preparing the hard coating films such as DLC, $\beta-C_3N_4$ Carbides, Nitrides, Borides etc. Now a electorn beam evaporation(EBE) broad beam metal ion source has been developed for this purpose in our lab. CN film has been formed by the EBE ion source. Study of the CN film shows that it has high hardness(HK=5800kgf/$\textrm {mm}^2$)and good adhesion. This method can widely changes the ratio of C/N atom's concentrations from 0.14 to 0.6 and has high coating rate. The low energy pocket ion source which was specially designed for surface texturing of medical silicon rubber was also developed. It has high efficiency and large uniform working zone. Both nature texturing and mesh masked texturing of silicon rubbers were performed. The biocompatibility was tested by culture of monocytes, and the results showed improved biocompatibility for the treated silicon rubbers. In addition, the TiB2 film synthesized by IBED is being studied recently in our lab. In this paper, the results which include the hardness, thickness of the films and the AES, XRD analysis as well as the tests of the oxidation of high temperature and erosion will be presented.

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심의고(深依考)

  • 김인숙
    • 복식
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    • 제1권
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    • pp.101-117
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    • 1977
  • This thesis is a study of the Simui(深衣) system which was a dress regulation peculiar to old China with skirt and coat. The origin of Simui is a very long time, that is, before Ju dynasty in China. Its wearing range had a large circle irrespective of rank and good or bad luck. This was a ordinary dress to the Emperor or the lords, a below court attire or a below sacrificial rites attire to the illustrious officials, and good luck dress to the common people. But this was a funeral rites attire or coming-of-age ceremony attire in domestic behaviour. In the times of Song dynasty, lots of confucian scholars had put on this simui because of Juhi's recommendation for domestic behaviour. This Simui had been put on through all the times of China and was the original text of all the dress. Especially the court attire and silkworm working dress of Empress, and the court attire and underwear court attire of Emperor is also made out of this Simui, therefore this is a origin of the ceremonial dress which formed into long coat. In Korea it is said that this Simui was brought in prior to the middle of Goryeo dynasty. But we can't tell the correct transmitted age. According to the following records in Goryeo History, "King had put on the Simui as a sacrificial rite attire in the times of Yejong". It is sure that this Simui was brought in prior to the times of Yejong. In fact, lots of confucian scholars had put on the Simui since the introduction of confucianism in the end of Goryeo dynasty and after that time this was taken by many confucian scholars through Yi dynasty. Korean Simui system was complied with Chinese system through confucian domestic behaviour, This was respected for court dress of confucian scholars, as it were, Chumri, (an ordinary dress of scholars), Nansam (a uniform of upper student), and Hakchangui (a uniform of confucian student). There are many deta about Simui system in the book of Yeki, chapter Okcho and Simui, and other many canfucian books. But we didn't demonstrate the theory about it till now. Especially there are diversifies of opinions about the phrase of "Sok Im Ku Byun" in Yeki. Simui was cut in separate and then was stitched together in one piece. Generally its shape had round sleeve and angled lapel, its length reaches to the anklebone. And it has a line around the lapel, the sleeve band, and the edge of skirt. It is called Simui because the body can be wrapped deeply in broad width and large sleeve. The Simui was made of white fine linen and was cut by the natural size of body. Every part of Simui had a profound meaning; the round sleeve in compliance with regulation can keep a courtesy when a walker moves his hands and the angled lapel like a carpenter's square in compliance with square keeps them front loosing their Justice and a string of the back also keeps them loosing from their righteousness and the flat lower part of Simui makes their heart and mind calm. This Simui was usually attendant on a head cover and belt made cloth, and black shoes. This thesis was made a study of documents and portrait from Yi dynasty, for the actual object was not obtained.

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LED 조명기구의 조도.휘도분포 특성 분석에 관한 연구 (Study on Analysis of Characteristics of Illuminance and Luminance Distribution of LED Luminaires)

  • 이진숙;김원도;김병수;한원탁
    • 조명전기설비학회논문지
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    • 제22권9호
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    • pp.1-7
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    • 2008
  • 본 연구의 목적은 형광등조명기구와 LED 조명기구와의 물리적 특성을 비교하여 LED조명기구의 기본적인 특성을 분석하는데 있다. 여기서 두가지 조명기구의 균제도 및 휘도분포 측면에서 비교 분석하여 LED조명기구를 건축실내공간에 적용하기 위한 자료를 작성하였다. 연구는 4단계로 나누어 진행하였다. 첫째, 기존의 조명기구와 비교한 LED조명광원의 이론적인 검토를 하였다. 둘째, 연구의 목적에 부합되도록 실험변인을 조절할 수 있는 실물대모형(Mock-up)을 제작하였다. 셋째, 설치된 실물대의형을 이용하여 조명기구별 균제도 휘도분포를 측정하였다. 최종적으로, 기존의 형광등기구와 LED조명기구간의 균제도 휘도분포 특성을 비교분석하였다. 연구결과 LED조명기구가 균제도 0.569로 기존 형광등조명기구의 균제도 0.522보다 높아 균일한 조도분포 특성을 보이고 전반확산이 양호한 것으로 나타났다. 또한 휘도분포를 측정한 결과 LED조명기구가 보다 균일한 휘도분포 특성을 보였고, 벽면의 휘도분포는 형광등조명기구에 의한 최대휘도가 $180.6[cd/m^2]$, LED조명기구는 $155.26[cd/m^2]$로 형광등이 높고, 평균휘도는 형광등조명기구가 $44.32[cd/m^2]$, LED조명기구가 $58.65[cd/m^2]$로 LED조명기구가 높게 나타났다. 이상의 결과로 볼 때, LED조명기구가 형광등조명기구보다 재실자에게 보다 쾌적한 작업환경을 구성할 수 있는 조명이라 판단된다.