• 제목/요약/키워드: X-RD

검색결과 272건 처리시간 0.028초

능동소자의 접합 커패시턴스를 이용한 VCO 설계에 관한 연구 (A Study on the Design of VCO Using Junction Capacitance of Active Element)

  • 강석엽;박욱기;고민호;박효달
    • 한국항행학회논문지
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    • 제8권1호
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    • pp.57-65
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    • 2004
  • 본 논문에서는 경량화, 소형화 가격절감에 맞추어 전압 제어 발진기의 공진기 부분에 바랙터 다이오드를 사용하지 않고, 발진부에 사용된 트랜지스터의 베이스 단에 제어 전압을 인가하여 TR 내부 커패시턴스를 변화시키므로 하여 X/Ku 대역 민수용 RD에 사용 가능한 전압 제어 발진기를 설계 및 제작하였다. 시뮬레이션을 수행 한 결과 설계한 전압 제어 발진기는 4.25 V에서 4.80 V까지의 제어 전압에 의하여 약 110 MHz의 주파수 동조 범위를 보였으며, 11.46 GHz 동작 주파수에서 9.63 dBm의 출력 및 1 MHz의 옵셋 주파수에서 -107.2 dBc의 위상잡음 특성을 나타내어 상용 목적에 적합한 성능을 내었다.

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심실중격결손을 합병한 Valsalva's 동 동맥류 파열의 치험예 (Surgical Treatment for Aneurysm of Sinus of Valsalva Combined with Ventricular Septal Defect)

  • 권중혁
    • Journal of Chest Surgery
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    • 제12권1호
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    • pp.43-49
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    • 1979
  • This is a case report of surgically treated rupture of Valsalva Sinus aneurysm combined with VSD. He has been relatively healthy until about one month before admission, when during bath, he felt abruptly palpitation, left chest pain and exertional dyspnea. These symptoms have progressed. On admission, thrill was palpable and continuous machinery murmur was audible on 2nd and 3rd intercostal space along the left sternal border. A rupture of Valsalva`s sinus aneurysm was confirmed by aortography and echocardiography but a small VSD was found by cardiotomy in open heart surgery. On 11th Sep. 1978, open heart surgery was performed. Valsalva`s sinus aneurysm came out from right coronary aortic sinus and ruptured into the right ventricle. It sized 1.2X1.5X1.5 cm. Ruptured opening was noted on apex of aneurysm [0.8X0.8cm], VSD [1. 0X0. 3cm in size] was just below the aortic annulus. The aneurysmal sac was removed on neck. After that, VSD and aneurysmal orifice were closed together with interrupted mattress sutures on same plane. The postoperative course was uneventful and discharged three weeks after open heart surgery.

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가역적 Hologram 소자개발을 위한 비정질 (Se,S)계 박막 특성에 관한 연구 (A study on the properties of amorphous (Se,S)-system thin films for reversible hologram device development)

  • 김상덕;이재규;김종빈
    • 전자공학회논문지A
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    • 제31A권12호
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    • pp.71-79
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    • 1994
  • In this paper, $As_{40}Se_{50-x}S_[x}Ge_{10}$(x=0, 25, 35, at.%) bulk and thin films, to develope device of reversible hologram, proved amorphous by X-RD analysis. On the thin films with composition rate, as Se-doped-quantity increased, absorption edge shifted to long wavelength, and we found that reversible photodarkening effect occurred when thin films are exposed and annealed. Optical energy gap was larger when thin films are annealed than exposed. In this effect thin films structurally stabilized by annealing. It is to formed grating hologram by the bragg method on the $As_{40}Se_{15}S_[35}Ge_{10}$ thisn films with the best transmittance properties As polariging angle grew larger, we found that maximum diffraction efficiency became smaller, and obtained it of 4.5% on the thin fim thicknesss of 0.6 m, polarizing angle of 40$^[\circ}$ and exposing for 20sec.

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양측 난소의 악성 종양으로 오인한 난소의 면역글로불린 G4 관련 질환 (Immunoglobulin G4-Related Disease of the Ovary Mimicking Bilateral Ovarian Malignancies)

  • 심용식;정택;정대철;김현수;오영택
    • 대한영상의학회지
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    • 제81권4호
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    • pp.996-1002
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    • 2020
  • 면역글로불린 G4 관련 질환은 신체 전 장기를 침범할 수 있는 전신적인 섬유-염증성 질환이다. 면역글로불린 G4 관련 질환이 난소를 침범한 경우는 드물어서 현재까지 2건의 증례만이 보고되었다. 컴퓨터단층촬영 및 자기공명영상에서 양측 난소의 악성 종양으로 오인되었으나 병리학적으로 면역글로불린 G4 관련 질환으로 진단한 증례를 보고하고자 한다.

OSCILLATORY BEHAVIOR AND COMPARISON FOR HIGHER ORDER NONLINEAR DYNAMIC EQUATIONS ON TIME SCALES

  • Sun, Taixiang;Yu, Weiyong;Xi, Hongjian
    • Journal of applied mathematics & informatics
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    • 제30권1_2호
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    • pp.289-304
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    • 2012
  • In this paper, we study asymptotic behaviour of solutions of the following higher order nonlinear dynamic equations $$S_n^{\Delta}(t,x)+{\delta}p(t)f(x(g(t)))=0$$ and $$S_n^{\Delta}(t,x)+{\delta}p(t)f(x(h(t)))=0$$ on an arbitrary time scale $\mathbb{T}$ with sup $\mathbb{T}={\infty}$, where n is a positive integer, ${\delta}=1$ or -1 and $$S_k(t,x)=\{\array x(t),\;if\;k=0,\\a_k(t)S_{{\kappa}-1}^{\Delta}(t),\;if\;1{\leq}k{\leq}n-1,\\a_n(t)[S_{{\kappa}-1}^{\Delta}(t)]^{\alpha},\;if\;k=n,$$ with ${\alpha}$ being a quotient of two odd positive integers and every $a_k$ ($1{\leq}k{\leq}n$) being positive rd-continuous function. We obtain some sufficient conditions for the equivalence of the oscillation of the above equations.

Oscillation of Second-Order Nonlinear Forced Functional Dynamic Equations with Damping Term on Time Scales

  • Agwa, Hassan Ahmed;Khodier, Ahmed Mahmoud;Ahmed, Heba Mostaafa Atteya
    • Kyungpook Mathematical Journal
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    • 제56권3호
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    • pp.777-789
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    • 2016
  • In this paper, we establish some new oscillation criteria for the second-order forced nonlinear functional dynamic equations with damping term $$(r(t)x^{\Delta}(t))^{\Delta}+q({\sigma}(t))x^{\Delta}(t)+p(t)f(x({\tau}(t)))=e(t)$$, and $$(r(t)x^{\Delta}(t))^{\Delta}+q(t)x^{\Delta}(t)+p(t)f(x({\sigma}(t)))=e(t)$$, on a time scale ${\mathbb{T}}$, where r(t), p(t) and q(t) are real-valued right-dense continuous (rd-continuous) functions [1] defined on ${\mathbb{T}}$ with p(t) < 0 and ${\tau}:{\mathbb{T}}{\rightarrow}{\mathbb{T}}$ is a strictly increasing differentiable function and ${\lim}_{t{\rightarrow}{\infty}}{\tau}(t)={\infty}$. No restriction is imposed on the forcing term e(t) to satisfy Kartsatos condition. Our results generalize and extend some pervious results [5, 8, 10, 11, 12] and can be applied to some oscillation problems that not discussed before. Finally, we give some examples to illustrate our main results.

CHARACTERIZATIONS OF STABILITY OF ABSTRACT DYNAMIC EQUATIONS ON TIME SCALES

  • Hamza, Alaa E.;Oraby, Karima M.
    • 대한수학회논문집
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    • 제34권1호
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    • pp.185-202
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    • 2019
  • In this paper, we investigate many types of stability, like (uniform stability, exponential stability and h-stability) of the first order dynamic equations of the form $$\{u^{\Delta}(t)=Au(t)+f(t),\;\;t{\in}{\mathbb{T}},\;t>t_0\\u(t_0)=x{\in}D(A),$$ and $$\{u^{\Delta}(t)=Au(t)+f(t,u),\;\;t{\in}{\mathbb{T}},\;t>t_0\\u(t_0)=x{\in}D(A),$$ in terms of the stability of the homogeneous equation $$\{u^{\Delta}(t)=Au(t),\;\;t{\in}{\mathbb{T}},\;t>t_0\\u(t_0)=x{\in}D(A),$$ where f is rd-continuous in $t{\in}{\mathbb{T}}$ and with values in a Banach space X, with f(t, 0) = 0, and A is the generator of a $C_0$-semigroup $\{T(t):t{\in}{\mathbb{T}}\}{\subset}L(X)$, the space of all bounded linear operators from X into itself. Here D(A) is the domain of A and ${\mathbb{T}}{\subseteq}{\mathbb{R}}^{{\geq}0}$ is a time scale which is an additive semigroup with property that $a-b{\in}{\mathbb{T}}$ for any $a,b{\in}{\mathbb{T}}$ such that a > b. Finally, we give illustrative examples.

사회정보처리 모델에 따른 아동의 공격성에 관한 연구 (A Social Information Processing Approach to the Study of Children's Aggression)

  • 안지영;박성연
    • 아동학회지
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    • 제13권2호
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    • pp.161-174
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    • 1992
  • The purpose of this study was to examine the differences between aggressive and nonaggressive boys with the use of a social information processing approach. The subjects were 80 3rd & 6th grade boys selected from a public elementary school in Seoul. The subjects were interviewed individually. Following the presentation of each story, five questions were asked. A 2 x 2 Analysis of Variance was performed for each of the 5 dependent measures. Results showed (1) Aggressive boys were more likely to attribute a hostile intention to the behavior of peer. (2) Aggressive boys predicted their own response as more hostile and aggressive. (3) The 6th graders generated more alternative solutions than the 3rd graders. (4) Non significant results are not reported in the abstract. (5) Aggressive boys were likely to choose an ineffective solution.

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국내외 제품담배의 tar, nicotine 및 vapour phase 이행량 비교

  • 김정열;신창호;김종열
    • 한국연초학회지
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    • 제20권2호
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    • pp.225-230
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    • 1998
  • A comparative study of major brands of domestic and imported cigarettes saled in market has been conducted. The total amounts of total particulate matter(TPM), tar and nicotine delivered from cigarettes, as well as the amounts of tar, nicotine in puff by puff were determined in the mainstream smoke of 6 brands. In addition, the relative amounts of vapour phase in 3rd puff smoke were determined. Results showed that the amounts of TPM and tar delivered from domestic brands were similar to the imported brands and the amounts of total nicotine delivered from domestic brands were higher than those of imported brands. As the domestic cigarettes nicotine/tar(N/T X 100) ratio was 9.5-10.3, the imported one's was 5.6-8.1. However, the amounts of tar and nicotine in puff by puff for the domestic brands were lower than those of the imported cigarettes and the relative amounts of vapour phase in 3rd puff smoke for the domestic cigarettes were lower than those of the imported cigarettes.

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