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와권(渦巻)노즐의 이론분석(理論分析)(I) -노즐의 구조(構造)에 관(關)하여- (Theoretical Analysis on the Swirl Type Nozzle(I) -Structures of the Swirl Nozzle-)

  • 이상우;사카이 준;후지키 도쿠미
    • Journal of Biosystems Engineering
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    • 제13권3호
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    • pp.1-10
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    • 1988
  • Fraser, Dombrowski, Tanasawa 그리고 Momono 등(等)이 분구(噴口)에 대(對)한 중자도구(中子導溝) 단면적(斷面積)의 비(比)에 기초을 두고 있는 Nozzle Parameter가 클수록 유량계수(流量係數)는 증가(增加)한다고 보고(報告)하였다. 그러나 노즐의 구조(構造)는 중자도구(中子導溝) 및 와실(渦室)의 형상(形狀)에 따라서 특성(特性)을 가지고 있고 구조(構造)의 특성(特性)은 유량계수(流量係數), 분무각(噴霧角) 및 살포도(撒布度)에 지대한 영향을 미친다. 노즐구조(構造)에 관(關)한 이론분석(理論分析)의 결과(結果)는 다음과 같다. 중자도구변(中子導溝邊)(d), 중자(中子)두께(t) 및 중자도구각(中子導溝角)(${\theta}$) 등(等)의 관계(關係)가 와실유선각(渦室流線角)(${\theta}_c$)에 미치는 영향은 $$tan({\theta}_c)=\frac{t{\cdot}sin^2{\theta}}{d-t{\cdot}sin{\theta}{\cdot}(1-cos{\theta})}$$ 또한 와실유선각(渦室流線角)(${\theta}_c$)이 중자도구각(中子導溝角)(${\theta}$)과 일치(一致)하는 관계(關係)는 $\frac{d}{t}=sin{\theta}$이다. 와실유선각(渦室流線角)과 와실형상(渦室形狀)과의 관계(關係)는 $$tan({\theta}_c){\qeq_-}\frac{r_c-r_g}{L_c}$$ 이며 와실유선각(渦室流線角)은 와실유선회전반경(渦室流線回轉半徑)과 와실(渦室)길이의 비(比)에 의(依)하여 변화(變化)함을 시사(示唆)한다. Swirl core가 Swirl plate보다는 생산비(生産費)의 고려없이 압력손실(壓力損失) 및 마찰손실 면(面)에서 더욱 합리적(合理的)으로 고려(考慮)된다.

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토목섬유를 이용한 보강토옹벽의 개발 (A Study on the Development of Reinforced Earth wall by Geotextile)

  • 도덕현;유능환
    • 한국농공학회지
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    • 제28권2호
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    • pp.63-73
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    • 1986
  • The model was developed by applying the principles of Bacot and Vidal to measure the behavior of deformation of the reinforced earth wall, and various tasts were performed by using the plastic fabric filter and the galvanized steel plate as a strip. The results obtained are as follows; 1. When the reinforced earth wall is deformed by the load, the strip is completely reinforced by the backfill materials and changed to the rigid block state, under the state of failure which permits sliding only, the next theoretical equation is formed. (H/L) . tan$\theta$ [cosO-sinOtanO] =2sinO[tan($\theta$ +0) +tanO] 2.The degree of the mutual reinforcement of the backfill material and the strip depend on the physical characteristics of the each material especially the angle of shearing resistance of the backfill material is desirable over 20$^{\circ}$ and, if it is over 400, its function could be a maximum. 3.The distribution of the maximum tensile strain of the reinforcement is changing with the height of reinforced earth wall, and when the height from bottom of the reinforced earth wall is 1.85 to 3. 35m, the maximum tensile strain appears at 2m from the skin element. The maximum tensile strain is increased by the depth of the reinforced earth wall from surface, and increased with the lapse of time after construction. 4.The failure surface of the reinforced earth wall by the concrete skin was about 60$^{\circ}$and the failure behavior of the reinforced earth wall in which the fabric filter was buried was slow, and so the pore pressure could be decreased. 5.It is possible to construct the fabric retained earth wall by the plastic fabric filter only. And the reinforcing effect between the steel plate and the plastic fabric filter is not largely different. however, in the aspect of the economic durability, the plastic fabric filter is more advantageous. 6.The reinforcing action mainly depends on the width and the length of the reinforcing materials, if possible, the full width is advantageous to enlarge the contact area with backfill. but considering the economic aspect, it is neccessary to develop the method controlling the space of the strip.

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GFP를 이용하여 in-vivo에서 추적한 Bad와 Bcl-XL의 Mitochondria 이동 (Bad Translocation to Mitochondria with Bcl-XL Traced in-vivo by Using GFP)

  • 윤수한;김진영;박승우;안영환;안영민;조기홍;조경기
    • Journal of Korean Neurosurgical Society
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    • 제29권10호
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    • pp.1283-1288
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    • 2000
  • Objectives : The subcellular locations of Bad, Bid, Bax and Bcl-XL change during apoptosis and this change is important for the regulation of cell death. The purpose this study was to elucidate binding of Bad with Bcl-XL in vivo Methods : We mads Bad with Green Fluorescent Protein(GFP) using PCR method. We transfected and overexpressed GFP-Bad with or without Bcl-XL cotransfection in living COS-7 cell. Results : Bad and Bcl- XL bind one another in healthy living cells and this association controled mitochondrial docking. In the absence of Bad-XL, Bad was mainly cytosolic and partially bound to mitochondria. Upon coexpression of Bad and Bcl-XL, most of Bad translocated to mitochondria. These should suggest that Bad binds to the mitochondrial and cytoplasmic forms of Bcl-XL and Bad bound to cytoplasmic Bcl-XL translocates to mitochondria. These in vivo findings confirm that Bad make a complexes with Bcl- XL and cause mitochondrial translocation of Bad-Bcl-XL complex.

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e-Health 시스템의 개념적 설계 방법론에 관한 연구 (Conceptual Design Methodology of an e-Health System)

  • 전제란
    • 한국산학기술학회논문지
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    • 제10권10호
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    • pp.2900-2906
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    • 2009
  • e-health 시스템은 의료부문에 관련된 이해당사자들에게 의료서비스와 정보를 정보통신기술을 이용하여 제공하는 것이다. 이런 상황에서 보건의료 분야에서 'e-Health' 시스템의 구축을 통해서 보건의료부문의 효율성 증진, 서비스질의 향상, 의료비용의 감소 그리고 관련 산업 발전에 따른 대외경쟁력 강화를 위한 돌파구를 마련하고 있다. 의료분야가 다른 산업분야에 비해서 매우 전문적이고 폐쇄적이어서, 인터넷 기술을 적용하는데 어려움이 많다. 그래서 인터넷의 사용자 중심적인 속성을 의료분야에 활성화시켜야 소정의 목적을 이룰 수 있을 것이다. 본 연구에서는 의료 부문에서의 인터넷을 이용한 e-Health 시스템의 개념과 특성 그리고 유형을 고찰하고, 한국의 의료부문을 위한 e-Health 시스템의 구축을 위한 보다 진보된 새로운 개념의 설계 방법론을 연구하기로 한다. 본 연구자에 의해 제안된 발전된 모형의 방법론을 AHP 기법을 이용하여 그 타당성과 적용가능성을 검증해보도록 한다. 본 연구는 e-Health 시스템의 발전 및 활성화를 위한 정책개발 및 실현에 기초자료가 될 수 있을 것으로 기대한다.

The Inhibition of TREK2 Channel by an Oxidizing Agent, 5,5'-dithiobis (2-nitrobenzoic acid), via Interaction with the C-terminus Distal to the 353rd Amino Acid

  • Park, Kyoung-Sun;Bang, Hyo-Weon;Shin, Eun-Young;Kim, Chan-Hyung;Kim, Yang-Mi
    • The Korean Journal of Physiology and Pharmacology
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    • 제12권4호
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    • pp.211-216
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    • 2008
  • TREK (TWIK-RElated $K^+$ channels) and TRAAK (TWIK-Related Arachidonic acid Activated $K^+$ channels) were expressed in COS-7 cells, and the channel activities were recorded from inside-out membrane patches using holding potential of - 40 mV in symmetrical 150 mM $K^+$ solution. Intracellular application of an oxidizing agent, 5,5'-dithio-bis (2-nitrobenzoic acid) (DTNB), markedly decreased the activity of the TREK2, and the activity was partially reversed by the reducing agent, dithiothreitol (DTT). In order to examine the possibility that the target sites for the oxidizing agents might be located in the C-terminus of TREK2, two chimeras were constructed: TREK2 (1-383)/TASK3C and TREK2 (1-353)/TASK3C. The channel activity in the TREK2 (1-383)/TASK3C chimera was still inhibited by DTNB, but not in the TREK2 (1-353)/TASK3C chimera. These results indicate that TREK2 is inhibited by oxidation, and that the target site for oxidation is located between the amino acid residues 353 and 383 in the C-terminus of the TREK2 protein.

적응형 영상 워터마킹 알고리즘 개발 (Development of Adaptive Digital Image Watermarking Techniques)

  • 민준영
    • 한국정보처리학회논문지
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    • 제6권4호
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    • pp.1112-1119
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    • 1999
  • 디지털 워터마킹(digital watermarking)이란 영상이나 비디오, 오디오, 텍스트 등의 저작물에 잘 식별되지 않는 표시를 삽입하여 저작권을 보호하는 방법으로 소유권자의 동의 없이 저작물을 배포, 복사되는 것을 방지하는 방법이다. 주파수 공간에서의 적응형(adaptive) 워터마킹 알고리즘을 제안한다. 본 논문에서는 워터마크를 삽입하기 위해서 사인(sin)함수와 코사인(cos)함수를 이용한 푸리에(Fourier) 급수전개를 이용하였다. 우선, 원 이미지를 주파수 영역을 변환한 다음 워터마크를 삽입할 위치를 저주파 대역으로 한정지어 결정하였으며, M 개의 파형을 가장 직교성(orthogonality)이 좋다고 하는 사인함수와 코사인함수를 이용하여 푸리에 급수 전개를 하였다. 이때, 사인과 코사인의 n 차 고조파는 Random Sequence를 발생하여 결정하였다. 제안한 알고리즘은 이와 같이 푸리에급수전개를 했을 때 각 항의 푸리에 계수를 산출하여 이 푸리에계수에 워터 마크를 삽입하였다. 실험결과 JPEG 압축, 블러링(Bluring), 노이즈 삽입 등의 이미지 왜곡에 대하여 워터마크 상관관계가 최소 0.5467에서 최대 0.9507까지의 견고성(robustness)을 보였다. 본 논문에서는 256$\times$256 크기의 8비트 256 명암값(gray-level)을 갖는 Lenna 이미지를 이용하였다.

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무정전 활선작업 피교육자를 위한 3차원 몰입형 가상환경 교육시스템의 개발 (3DImmersion Type Virtual Environment System : Training Interruption-free Live-Line Workers)

  • 정영범;박창현;김기현;장길수
    • 대한전기학회논문지:전력기술부문A
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    • 제53권1호
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    • pp.22-30
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    • 2004
  • As an information-oriented society comes, many people use PC and depend on database that network server has. However, the online data can be missed when a blackout happens and also a power failure effects on standard of judgment on Power Quality. Thus, it is reason of a trend using interruption-free live-line work when a trouble happens to power system. However, the 83% among the number of people who receive an electric shock experience when a laborer is doing interruption-free live-line works. In interruption-free method, the education and the training problem has been issued. However, we have a few instructors for that training. Furthermore, the trainees have short training period, just 4 weeks. In this paper, to develope the method that has no restriction of a time and place and reduce the wasteful materials, immersion type virtual reality(or environment) technology is used. The users of a 3D immersion type VR training system can interact with the system by doing same action in the real safe environment. Thus, it can be valuable to apply this training system to a dangerous work like as "Interruption-free live-line work exchanging COS(Cut-Out-Switch)". In this program, the user works with a instruction on the window and speaker and can't work other tasks until each part of the task completed. The workers using this system can use their hands and viewpoint movement as he is in a real environment but the trainee can't use all parts and senses of a real body with the current VR technology. Despite of this weak point, when we consider the trends of improvement in electrical devices and communication technology, we can say that 3D graphic VR application has a high potentiality.

$L_1-B_4$ 모드 유니몰프형과 바이몰프형 진동자를 이용한 선형 초음파 모터의 특성 (Characteristics of Linear Ultrasonic Motor Using $L_1-B_4$ Mode Unimorph-TyPe and Bimorph-Type Vibrator)

  • 김범진;정동석;김태열;박태곤;김명호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제50권9호
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    • pp.427-433
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    • 2001
  • A linear ultrasonic motor was designed by a combination of the first longitudinal and fourth bending mode, and the motor consisted of a straight aluminum alloys bar bonded with a piezoelectric ceramic element as a driving element. That is,$L_1-B_4$ linear ultrasonic motor can be constructed by a multi-mode vibrator of longitudinal and bending modes. Linear ultrasonic motors are based on an elliptical motion on the surface elastic body, such as bar or plates. In general, the natural resonance frequency of the stator is used as a driving frequency of the motor which provides a large elliptical motion. The corresponding eigenmode of one resonance frequency can be excited twice at the same time with a Phase shift of 90 degrees in space and time. And the rotation can be reversed by changing the phase between the two signals from sin$\omega$t to cos$\omega$t. Moreover, the tangential force pushes the slider(rotor) and, therefore, determines the thrust and speed of the motor. The experimental results of fabrication motors, bimorph-tyPe motor showed more excellent than unimorph-type. The maximum speed of TBL-200, TBL-300, TBL-400, TBL -220, TBL-310 and TBL-420 motors were 0.12, 0.37, 0.39, 0.14, 0.55 and $0.60ms6{-1}$, respectively. And the efficiency were reported 1.15, 7.9, 6.6, 2.36, 10.1 and 16.5%, respectively. That time, output thrust of the motor was a strong(1~2N) and the weight of stator was a lightness(5~7g).

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$Ni_{53}-Fe_{47}$ 자성박막의 신형전류자기 기전력효과 (Galvanomagnetic electromotive force effect of Magnetic $Ni_{53}-Fe_{47}$ Thin Films)

  • 정한;손희영;김미양;장현숙;이장로;이용호
    • 한국자기학회지
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    • 제4권3호
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    • pp.272-276
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    • 1994
  • 진공증착방법으로 제작한 $Ni_{53}-Fe_{47}$ 박막에 관한 신형전류자기 기전력효과의, 전류와 자장 방향이 만드는 각 $\theta$ 의존성이, 자기저항효과의 $cos\;2{\theta}$, Hall 1효과의 경우 $sin\;{\theta}$임에 대하여 $sin\;2{\theta}$로 관측되고, 이 효과의 자장에 의존하는 전압변화율이 자기저 항효과의 비교할 때 차수가 다르게 큰 것이 조사된다. 이 효과가 2 Carrier형 모델로 이해할 수 있음을 이론적으로 확인된다.

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저출력레이저조사가 섬유아세포와 면역세포의 증식 및 유전자발현에 미치는 영향 (Effects of Low Level Laser on the Proliferation and Gene Expression of Fibroblasts and Immune Cells)

  • Ik-Jun Lim;Keum-Back Shin;Bok Choi
    • Journal of Oral Medicine and Pain
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    • 제20권1호
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    • pp.53-65
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    • 1995
  • The growth and synthetic activities of fibroblasts are regulated by cytokines and growth factors derived from activated inflammatory cells. Stimulatory effect of low level laser (LLL) radiation on wound healing seems to be in part due to direct stimulatory action on cell proliferation and synthetic activities of fibroblasts. Also indirect stimulatory effect on the fibroblast function through inflammatory or immune cells is another possible mechanism of biostimulatory action of LLL. This study was performed to determine the growth rate of human gingival fibroblasts obtained biopsy and culture, fibroblast cell line, and immune cell line by using $[^3H]-$ thymidine incorporation test. And gene expression pattern was also analyzed by using the DNA probe such as Hsp70, IL-1$\beta$, MIP-1$\alpha$ and actin cDNA. Proliferation rate of gingival fibroblast was increased by LLL irradiation, but no more effect was added by LPS or IL-1$\beta$ pretreatment Enhanced Hsp70 gene expression was found from gingival fibroblasts and fibroblast cell line COS by LLL irradiation., which was not more increased by LPS or IL-1$\beta$ pretreatment. LLL-irradiated promyelcytic cell line HL-60 and macrophage cell line RAW264.7 showed significant stimulatory effect of proliferation rate when compared with respective control. However there were no changes in growth rate of other immune cell tested in this study, such as B cell line WR19n.l and 230, helper T cell line Jurkat and Hut78, cytolytic T cell line CTLL-r8. By LLL-irradiation Hsp70 gene expression was increased in RAW246.7 and HL-60, not in CTLL-R8. And IL-1$\beta$ and MIP-1$\alpha$ gene expression were induced only from LLL-irradiated RAW264.7. These results led us to presume that LLL radiation may affect to the immune cells, especially to macrophage, through which it might promote wound healing process.

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