• 제목/요약/키워드: Lee Jung-Eom

검색결과 392건 처리시간 0.035초

Effect of Alkaline-Earth Oxide Additives on Flexural Strength of Clay-Based Membrane Supports

  • Lee, Young-Il;Eom, Jung-Hye;Kim, Young-Wook;Song, In-Hyuck
    • 한국세라믹학회지
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    • 제52권3호
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    • pp.180-185
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    • 2015
  • Low-cost ceramic membrane supports with pore sizes in the range of $0.52-0.62{\mu}m$ were successfully prepared by uniaxial dry compaction method using inexpensive raw materials including kaolin, bentonite, talc, sodium borate, and alkaline-earth oxides in carbonate forms (e.g., $MgCO_3$, $CaCO_3$, and $SrCO_3$). The prepared green supports were sintered at $1000^{\circ}C$ for 8 hr in air. The effect of alkaline-earth oxide additives on the flexural strength of clay-based membrane supports was investigated. The porosity of the clay-based membrane supports was found to be in the range of 33-34%. The flexural strength of the clay-based membrane supports with 1% alkaline-earth carbonates was found to be in the range of 42.8-52.7 MPa. The addition of alkaline-earth carbonates to clay-based membrane supports resulted in large increases (47-80%) in the flexural strength of the membrane supports, compared to that of membrane supports without alkaline-earth carbonates. The typical flexural strength of the clay-based membrane support with 1% $SrCO_3$ was 52.7 MPa at 33.8% porosity.

첨가제의 조성이 폐유리-점토 타일의 곡강도에 미치는 영향 (Effect of Additive Composition on Flexural Strength of Cullet-Loess Tile Bodies)

  • 이영일;엄정혜;김영욱;송인혁
    • 한국세라믹학회지
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    • 제50권6호
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    • pp.416-422
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    • 2013
  • Cullet-loess tile bodies are successfully fabricated using cullet, loess, hollow microspheres, and sintering additives (borosilicate glass frit, boric acid, or fumed silica) as starting materials. The effects of the additive composition and sintering temperature on the sintered density and flexural strength of the cullet-loess tile bodies are investigated. The sintered density of the cullet-loess tile bodies increases with an increase in the sintering temperature as a result of the enhanced densification of pore walls through the viscous flow of a liquid phase formed from the glass frit and sintering additives. The flexural strength of the cullet-loess tile bodies increases with increases in the sintering temperature and the cullet content in the starting composition. A maximal flexural strength of 40 MPa is obtained in cullet-loess tile bodies sintered with glass frit at $800^{\circ}C$ in air.

New polymeric host material for efficient organic electro phosphorescent devices

  • Jung, Choong-Hwa;Park, Moo-Jin;Eom, Jae-Hoon;Shim, Hong-Ku;Lee, Seong-Taek;Yang, Nam-Choul;Liand, Duan;Suh, Min-Chul;Chin, Byung-Doo;Hwang, Do-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.843-845
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    • 2009
  • A polymeric host for triplet emitters composed of N-alkylcarbazole and tetramethylbenzene units was successfully synthesized. Efficient energy transfer was observed between this polymeric host and green phosphorescent dyes. The device fabricated using 5 wt% green 1 in the polymeric host as the emitting layer showed the best performance. Thin films of this host-guest system, exhibiting clear stripe patterns could be prepared through the LITI process. The patterned films were then used to fabricate electrophosphorescent devices, which show performance characteristics similar to those of spin-coated devices. The new host material is a good candidate to be used in polymer-based full-color electrophosphorescent light-emitting displays.

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동기식 이더넷에서의 장치 동기화 방법 및 실시간 트래픽을 위한 대역폭 예약 (Device Synchronization Method and Bandwidth Reservation for Isochronous Traffic in Synchronous Ethernet)

  • 김민준;엄종훈;권용식;이정원;김승호
    • 한국통신학회논문지
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    • 제32권4B호
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    • pp.217-226
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    • 2007
  • 디지털 멀티미디어 장치의 증가에 따라 네트워크를 통하여 실시간 트래픽을 전송을 지원하기 위한 연구들이 많이 진행되고 있다. 이 중에서도 이더넷이 가지는 장점으로 이더넷을 이용한 네트워크 기술을 활용하는 방안에 초점이 맞춰지고 있다. 이더넷에서 실시간 트래픽을 지원하기 위한 네트워크 기술의 표준화는 IEEE 802.1 AVB TG에서 진행 중이다. 본 논문은 이더넷에서 실시간 트래픽을 지원하기 위한 기술, 즉 동기식 이더넷에서의 장치간의 동기화 방법을 제안한다. 그리고 동기가 맞추어진 장치에서 시간에 실시간 트래픽을 전송하기 위해 필요한 대역폭을 예약하는 방법을 제안한다. 본 논문에서 동기식 이더넷 모델은 OPNET을 통해 구현하였고 제안한 동기화 방법과 대역폭 예약 방법의 효율성을 분석하였다.

AFM 캔틸레버를 이용한 i-motif DNA의 구조 변화에 미치는 화학적 환경에 대한 연구 (Study on the chemical environment for conformational change of i-motif DNA by atomic force microscopy cantilever)

  • 정휘헌;박진성;양재문;이상우;엄길호;권태윤;윤대성
    • 센서학회지
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    • 제19권3호
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    • pp.214-220
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    • 2010
  • Three-dimensional(3D) structure of specific DNA can be changed between two conformations under an external environmental transition such as pH and salt concentration variations. We have experimentally observed the conformational transitions of i-motif DNA using AFM cantilever bioassay. It is shown that pH change of a solvent induces the bending defleciton change of a cantilever functionalized by i-motif DNA. This indicates that cantilever bioassay enables the label-free detection of DNA structural changes upon pH change. It is implied that cantilever bioassay can be a de novo route to quantitatively understand the conformational transitions of biological molecules under environmental changes.

신경회로망을 이용한 지능적 좌석 배치 시스템 (Intelligent Seat Align System Using Neural Network)

  • 최정연;김민철;정성부;이현관;엄기환
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2010년도 춘계학술대회
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    • pp.197-200
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    • 2010
  • 서비스 산업이 발달할수록 개인의 취향에 좋아하는 정보만을 제공받기 원하고 서비스를 받기 위한 대기시간이 길어지는 것을 좋아하지 않는다. 그러나 기존의 공연장, 극장, 도서관 등의 좌석관리 시스템은 개인의 취향에 맞게 자동으로 좌석 배치를 할 수 없으며 누구나 동일한 정보만 제공하여 준다. 본 논문에서는 이러한 문제점을 개선하기 위하여 개인의 취향에 맞게 즉 신체적인 조건이나 개인의 성향에 맞는 좌석을 지능적으로 배치하고, 선호하는 정보만을 제공할 수 있는 시스템을 제안한다. 제안한 시스템의 성능 확인을 위하여 임의의 극장 좌석 배치도를 이용하여 실험을 한 결과 우수한 성능을 보이는 것을 확인하였다.

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개에서 발생한 특발성 면역매개성 다발성관절염의 치료 증례 (A Case of Treatment of Idiopathic Immune-Mediated Polyarthritis in a Dog)

  • 엄나영;이희천;장효미;정동인
    • 한국임상수의학회지
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    • 제32권4호
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    • pp.366-369
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    • 2015
  • A 12-year-old, castrated male, mixed-breed dog was referred to us with a history of depression, lameness, neck and multiple joints pain. Clinical signs had been deteriorating from rear limbs lameness leading to pain on all four limbs lameness for 7 days. Mild leukocytosis and increased C-reactive protein concentration were revealed in blood work. On radiography, degenerative change of humerus and cervical intervertebral space narrowing were found. The results of synovial fluid analysis revealed severe neutrophilic pleocytosis, decreased viscosity, increased turbidity and bacterial culture was negative. The antinuclear antibody test was negative and MRI results revealed mild cervical intervertebral disk disease (IVDD). Based on all tests, we diagnosed this case as idiopathic immune-mediated polyarthritis (IMPA). Prednisolone and mycophenolate mofetil were administered and clinical signs were resolved after 7 days. This case report demonstrated that clinical, diagnostic imaging and synovial fluid analysis findings and successful treatment result with prednisolone and mycophenolate mofetil in canine idiopathic IMPA.

노약자 보호를 위한 무선 3축 가속도 센서를 이용한 움직임 검출 시스템 (Motion Activity Detection using Wireless 3-Axis Accelerometer Sensor for Elder and Feeble Person)

  • 최정연;정성부;이현관;엄기환
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2009년도 추계학술대회
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    • pp.565-568
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    • 2009
  • 본 논문에서는 노약자의 관찰을 위하여 움직임 센서를 이용하여 움직인 정보를 이용하는 방식을 제안한다. 사람이 물체를 움직일 때에 물체에 부착된 3축 가속도 센서를 이용해 움직임 데이터를 전달받고 전달받은 움직인 데이터를 SVM을 이용하여 물체의 움직임을 추정한다. 제안한 시스템의 유용성을 확인하기 위하여 실험에 이용한 데이터들을 데이터베이스화 하여 신경회로망의 학습에 사용하였고, 일상적으로 걸어갈 때, 빠르게 뛰어갈 때, 넘어질 때의 3가기 경우의 움직임을 제대로 검출해 내는가에 대한 실험을 하였다. 실험 경과 80% 이상의 검출 성공률을 볼 수 있었다.

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Mode Coupling within Inner Cladding Fibers

  • Lee, Byeong-Ha;Eom, Tae-Jung;Kim, Myoung-Jin;Paek, Un-Chul;Park, Tae-Sang
    • Journal of the Optical Society of Korea
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    • 제7권2호
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    • pp.53-58
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    • 2003
  • We report the formation of inner cladding modes in the optical fiber having an inner cladding structure. The inner cladding layer located between the core- and the cladding- layers of a conventional fiber might have, so called, inner cladding mode(s). The brief history of the inner cladding fiber and the spectral properties of the inner cladding mode are presented. By utilizing fiber gratings, the spectral properties of the inner cladding mode formed in Dispersion Compensating Fiber (DCF) are discussed. It was observed that one resonant peak of a long-period fiber grating was not sensitive to the variation on the cladding surface. With a fiber Bragg grating, a small group of unusual resonant Peaks was observed between the main Bragg Peak and the series of usual Peaks resulted from the mode coupling to counter-propagating cladding modes. Within the DCF by using fiber gratings, it is noted, at least one mode can be coupled to the inner cladding mode and a few outer cladding modes are severely affected by the inner cladding of the fiber.

First Report of Allantophomopsiella pseudotsugae Isolated from Soil in Korea

  • Wajihi, Ally Hassan;Lee, Seung-Yeol;Das, Kallol;Eom, Ahn-Heum;Jung, Hee-Young
    • 한국균학회지
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    • 제47권1호
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    • pp.29-34
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    • 2019
  • A fungal isolate designated 17E029 was isolated from a soil sample in Jeju, Korea. The strain was similar to other Allantophomopsiella species in its morphological characteristics such as grey mycelia, conidiophore, and conidia sizes. The isolate produced aerial mycelia, which appeared grey on the reverse side of the media surfaces and turned black on the front side of the colonies. The conidiophores emanating from the hyphae were hyaline, grey, aseptate, branched, and $6.7{\sim}9.2{\times}1.8{\sim}2.5{\mu}m$. Conidiogenous cells were ovoid to subcylindrical, discrete, guttulate, and hyaline. Conidia were hyaline, aseptate, smooth, guttulate, oval to subcylindrical, irregular in shape, and $6.0{\sim}7.8{\times}3.0{\sim}3.4{\mu}m$. The strain was confirmed based on phylogenetic analysis of the closest related organism, A. pseudotsugae CBS 288.37, using the partial 28S, internal transcribed spacer rDNA regions, and partial RNA polymerase II second largest subunit locus (RPB2) gene sequences along with its culture characteristics. Therefore, morphological observations and phylogenetic analysis revealed that strain 17E029 is similar to the previously identified A. pseudotsugae. Hence, this species was described as A. pseudotsugae strain 17E029, which is a new record in Korea.