• 제목/요약/키워드: manB

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보론산의 용액 화학 (Aqueous Chemistry of Boric Acid)

  • 이만승
    • 자원리싸이클링
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    • 제27권4호
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    • pp.23-28
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    • 2018
  • 보론을 함유한 광석이나 2차자원으로부터 보론을 효과적으로 회수하기 위한 습식공정을 개발하기 위해서는 수용액에서 보론산의 농도분포 자료가 필요하다. 보론산은 pH 6 이하의 용액에서 $B(OH)_3$로, pH 12 이상의 용액에서는 $B(OH)_4{^-}$로 존재한다. 그러나 pH 6에서 11사이의 범위에서는 $B(OH)_3$$B(OH)_4{^-}$간의 중합체 형성반응이 일어난다. $B_3O_3(OH)_4{^-}$, $B_4O_5(OH){_4}^{2-}$와 같은 중합체의 몰분율은 보론산의 농도에 비례한다.

원발성 서자진전 B형, 서자자세-특수성인가? (Primary Writing Tremor Type B, Writing Posture-specific?)

  • 서만옥
    • Annals of Clinical Neurophysiology
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    • 제2권2호
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    • pp.95-100
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    • 2000
  • Purpose : Primary writing tremor(PWT) can be classified as either type A or type B depending on whether tremor appeared during writing or whilst writing and also on adopting the hand postures normally used for writing. Through the clinical experience author has had an impression that PWT type B may not be purely dependant on specific writing postures. The objective of this study was to clarify whether PWT type B have writing posture-specificity or not. Results : The data indicated that type B PWT is not writing posture-specific. Various pronation and supination postures could evoke tremor as well as writing postures. Furthermore most of other pronation- and supination-related tasks could evoke tremors as well as action of writing. Conclusions : The present data suggest that PWT should be limited only on the pure form of task-spesific PWT type A.

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Vanapalli 등의 제안식을 적용한 화강풍화토 불포화사면의 안정성해석 (Slope Stability Analysis of Unsaturated Slope composed of Weathered Granitic Soils using the Equation of Vanapalli et al.)

  • 백환조;김경만;김대훈
    • 산업기술연구
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    • 제30권B호
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    • pp.3-10
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    • 2010
  • The numerical study was conducted using the equation of Vanapalli et al.(1996) related shear strength of unsaturated soils. Angle of shearing resistance(${\Phi}^b$) and angle of internal friction(${\Phi}^{\prime}$) appear identically in lower suction range, but angle of shearing resistance(${\Phi}^b$) has non-linearity as suction increases. Nevertheless, the numerical study was conducted using angle of shearing resistance(${\Phi}^b$) in even lower suction range because of limit of program function. However, behavior of real ground on applying numerical study can be analysed wrong by it. Therefore in this paper numerical analysis on applying the equation of Vanapalli et al.(1996) and ${\Phi}^b$ has been compared about unsaturated slope considering continuous rainfall.

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무선랜 기반의 복수 무인기 통신링크 최대 처리량 분석 (Theoretical Maximum Throughput (TMT) Analysis of the Multiple UAVs datalink system using WLAN (IEEE 802.11b))

  • 김인규;문상만
    • 항공우주기술
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    • 제12권2호
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    • pp.118-122
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    • 2013
  • 본 논문에서는 복수 무인항공기 통신장비로 IEEE 802.11b 기술을 적용할 때 기존 무선랜 표준서에서 제시한 송수신 지연시간과 최대 처리량을 근거로 하여 통신 가능한 무인항공기 대수와 전송 데이터량을 예측하였다.

K-Band Low Noise Receiver Module Using MMIC Technology

  • Yu, Kyung-Wan;Uhm, Man-Seok;Yom, In-Bok;Chang, Dong-Pil;Lee, Jae-Hyun
    • 한국전자파학회논문지
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    • 제11권1호
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    • pp.110-115
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    • 2000
  • A K-band GaAs MMIC receiver module has been developed using 0.15 ${\mu}{\textrm}{m}$ HEMT technology process. It incorporates two front end low noise amplifiers, a double balanced diode mixer, and filters. The RF input frequency ranges 20.1 to 21 GHz and the IF output 1.1 to 2 GHz. Test results show an overall conversion gain of more than 27 dB, and less than a 2.2 dB noise figure. The image-rejection ratio greater than 21 dB has been obtained. The isolation between RF and IF ports is better than 27 dB, and between LO and IF is more than 50 dB.

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Smooth Boundary Topology Optimization Using B-spline and Hole Generation

  • Lee, Soo-Bum;Kwak, Byung-Man;Kim, Il-Yong
    • International Journal of CAD/CAM
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    • 제7권1호
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    • pp.11-20
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    • 2007
  • A topology optimization methodology, named "smooth boundary topology optimization," is proposed to overcome the shortcomings of cell-based methods. Material boundary is represented by B-spline curves and their control points are considered as design variables. The design is improved by either creating a hole or moving control points. To determine which is more beneficial, a selection criterion is defined. Once determined to create a hole, it is represented by a new B-spline and recognized as a new boundary. Because the proposed method deals with the control points of B-spline as design variables, their total number is much smaller than cell-based methods and it ensures smooth boundaries. Differences between our method and level set method are also discussed. It is shown that our method is a natural way of obtaining smooth boundary topology design effectively combining computer graphics technique and design sensitivity analysis.

A note on the discrete time B/G/1 gated queueing system with vacations

  • Noh, Seung-Jong
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 1993년도 춘계공동학술대회 발표논문 및 초록집; 계명대학교, 대구; 30 Apr.-1 May 1993
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    • pp.49-56
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    • 1993
  • We consider a B/G/1 queueing system with vacations, where the server closes the gate when it begins a vacation. In this system, customers arrive according to a Bernoulli process. The service time and the vacation time follow discrete distributions. We obtain the distribution of the number of customers at a random point in time, and in turn, the distribution of the residence time (queueing time + service time) for a customer. This system finds an application in the performance evaluation of the DQDB protocol which has been adopted as the standard protocol for IEEE 802.6 MAN.

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