• 제목/요약/키워드: B.E.T

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빔폭에 의한 이동통신의 셀 섹터화 방식 비교 (Comparison of Cell Sectorization of Mobile Communications with Beam Width)

  • 최동유;이상덕;김영배;한승조
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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    • pp.693-697
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    • 2008
  • 일반적으로 CDMA 이동통신 시스템에서 효율적인 무선자원의 운영을 위해서는 일정 영역 내에서 무선자원의 재사용율을 높여야 하며, 이를 위해서는 동일 무선채널간의 신호간섭을 최소화해야 한다. 따라서 본 논문에서는 신호간섭을 최소화하고 경제적인 망구축과 주파수 이용 효율 증대를 위한 방안으로써 실질적으로 현장에 바로 적용 가능한 다양한 셀 섹터화(3섹터, 4섹터) 방식에 대하여 시뮬레이션을 수행하였다. 그리고 RSSi, $E_c/I_o$, $E_b/N_t$, 3-way 핸드오프의 시뮬레이션 결과를 비교 및 분석함으로써 그 활용가능성을 확인하였다.

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Splitting effect of photocurrent for $CdIn_2Te_4$ single crystal

  • You, Sang-Ha;Hong, Kwang-Joon
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.84-85
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    • 2009
  • The single crystals of p-$CdIn_2Te_4$ were grown by the Bridgman method without the seed crystal. From photocurrent measurements, it was found that three peaks, A, B, and C, correspond to the intrinsic transition from the valence band states of $\Gamma_7(A)$, $\Gamma_6(B)$, and $\Gamma_7(C)$ to the conduction band state of $\Gamma_6$, respectively. The crystal field splitting and the spin orbit splitting were found to be 0.2360 and 0.1119 eV, respectively, from the photocurrent spectroscopy. The temperature dependence of the $CdIn_2Te_4$ band gap energy was given by the equation of $E_g(T)=E_g(0)$ - $(9.43\times10^{-3})T^2$/(2676+T). $E_g(0)$ was estimated to be 1.4750, 1.7110, and 1.8229 eV at the valence band states of A, B, and C, respectively. The band gap energy of $p-CdIn_2Te_4$ at room temperature was determined to be 1.2023 eV.

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Binding energy study from photocurrent signal in $CdIn_2Te_4$ crystal

  • Hong, Kwang-Joon
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.376-376
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    • 2010
  • The single crystals of p-$CdIn_2Te_4$ were grown by the Bridgman method without the seed crystal. From photocurrent measurements, it was found that three peaks, A, B, and C, correspond to the intrinsic transition from the valence band states of $\Gamma_7$(A), $\Gamma_6$(B), and $\Gamma_7$(C) to the conduction band state of $\Gamma_6$, respectively. The crystal field splitting and the spin orbit splitting were found to be 0.2360 and 0.1119 eV, respectively, from the photocurrent spectroscopy. The temperature dependence of the $CdIn_2Te_4$ band gap energy was given by the equation of $E_g(T)=E_g(0)-(9.43{\times}10^{-3})T^2/(2676+T)$. $E_g$(0) was estimated to be 1.4750, 1.7110, and 1.8229 eV at the valence band states of A, B, and C, respectively. The band gap energy of p-$CdIn_2Te_4$ at room temperature was determined to be 1.2023 eV.

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Temperature dependence of photocurrent spectra for $AgInS_2$ epilayers grown by hot wall epitaxy

  • Baek, Seung-Nam;Hong, Kwang-Joon
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.123-124
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    • 2007
  • A silver indium sulfide ($AgInS_2$) epilayer was grown by the hot wall epitaxy method, which has not been reported in the liteniture. The grown $AgInS_2$ epilayer has found to be a chalcopyrite structure and evaluated to be high quality crystal. From the photocurrent measurement in the temperature range from 30 K to 300 K, the two peaks of A and B were only observed, whereas the three peaks of A, B, and C were seen in the PC spectrum of 10 K. These peaks are ascribed to the band-to-band transition. The valence band splitting of $AgInS_2$ was investigated by means of the photocurrent measurement. The temperature dependence of the energy band gap of the $AgInS_2$ obtained from the photocurrent spectrum was well described by the Varshni's relation, $E_g(T)=\;E_g(0)\;eV-(7.78\;{\times}\;10^{-4}\;eV/K)T^2/(T\;+\;116\;K\;K)$. Also, Eg(0) is the energy band gap at 0 K, which is estimated to be 2.036 eV at the valence band state A and 2.186 eV at the valence band state B.

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THE NUMBER OF POINTS ON ELLIPTIC CURVES EA0:y2=x3+Ax OVER $\mathbb{F}$p MOD 24

  • Park, Hwa-Sin;You, Soon-Ho;Kim, Dae-Yeoul;Kim, Min-Hee
    • 호남수학학술지
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    • 제34권1호
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    • pp.93-101
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    • 2012
  • Let $E_A^B$ denote the elliptic curve $E_A^B:y^2=x^3+Ax+B$. In this paper, we calculate the number of points on elliptic curves $E_A^0:y^2=x^3+Ax$ over $\mathbb{F}_p$ mod 24. For example, if $p{\equiv}1$ (mod 24) is a prime, $3t^2{\equiv}1$ (mod p) and A(-1 + 2t) is a quartic residue modulo p, then the number of points in $E_A^0:y^2=x^3+Ax$ is congruent to 0 modulo 24.

비정질 TbFeCo 합금 증착박막의 자기광학효과 (Magneto-optic effect of thermal evaporated amorphous TbFeCo thin flim)

  • 박용관;양계준
    • E2M - 전기 전자와 첨단 소재
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    • 제5권4호
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    • pp.439-445
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    • 1992
  • 최근 광자기 기록매체로 주목받고 있는 RE-TM계 비정질 박막을 T $b_{x}$ (F $e_{0.9}$ $Co_{0.1}$)$_{100-x}$ (x=14, 17, 20, 23, 27[at%])의 조성비를 갖는 모합금을 만든후 진공증착방법으로 합금박막을 제작하였다. 각시료의 조성에 따른 자기광학효과를 알아보기 위하여 80K부터 600K에서 포화자화( $M_{s}$ )와 보자력( $H_{c}$)에 대한 온도의존성과 자기이방성상수(Ku), Polar Kerr 이력곡선을 측정하였다. 또한 Curie 온도 근처에서 열처리 시간에 따른 자기 토크 곡선의 변화를 분석 함으로써 합금박막 표면의 산화정도를 정성적으로 평가할 수 있었다. 실험결과 T $b_{22.72}$(F $e_{68.78}$ $Co_{8.5}$)인 시료가 상온에서 8.4KOe의 보자력을 가졌으며 T $b_{x}$(x=23[at%])인 경우가 가장 큰 수직자기이방성을 나타냈다. Polar Kerr 이력곡선은 Tb함량 x=25~26[at%]에서 부호가 반전됨을 알 수 있었다.다.다.다.

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토양의 침식과 보존에 관한 이론적 분석 2. 토양침식의 내성에 관한 이론 (The Theoretical Analyses of the Soil Erosion and Conservation 2. The Theoretical Expresion of Erosion Tolerance for the Soil Conservation)

  • 장남기
    • 아시안잔디학회지
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    • 제10권1호
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    • pp.31-40
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    • 1996
  • The mechanical expresion provides for the use of Soil property reserves and permanent protec-tion or improvement of soil resources in accordance with measurable standards. If the functions I (initial soil property), E (soil erosion), R (soil renewal), and M. (minimum allowable value) are assumed to be integrable in region A, erosion tolerance over a region is leaded to ${\int}_A{\int}I(m, cl, re, ch, b)dA-{\int}_A{\int}{\{\int}_{to}^{\infty}[E(w, re, c, re, ch, b, t)-R(m, ch, re, b, t)]dt}\dA{\geqq}{\int}_A{\int}M_i(m, cl, re, ch, b)dA$ were variable factors are m=parent material of soil, cl=climate, re=relief or topography, ch=soil characteristics, r=rain or water, w=wind, b=biota, and t=time.

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지실(枳實)에 의한 면역(免疫)글로블린 E 생성(生成)의 억제효과(抑制效果) (Inhibitory Effect of Immunoglobulin E Production by Poncirus tripoliata)

  • 김형균;권용택
    • 대한한의학회지
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    • 제19권1호
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    • pp.419-429
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    • 1998
  • Poncirus trifoliata (L.) Raf (Rutaceae) fruits (PTFE) has been used for the treatment of allergic disease. IgE is normally one of the least abundant immunoglobulin (Ig) isotypes in the serum of both humans and several species of experimental animals: however a number of different stimuli can result in profound increases in IgE levels relative to other isotypes. In rodents, infection with many parasitic helminths can cause approximately 100-fold elevation in IgE within 2 wks. Immunization of mice with small amounts of protein antigens on alum also results in 10-fold to fold increase in total serum IgE, much of it specific for the immunizing antigen. In this experiment, I investigated the effect of an aqueous extract of Poncirus trifoliata (L.) Raf (Rutaceae) fruits (PTFE) on a in vivo and in vitro IgE production. PTFE dose-dependently inhibited the serum levels of IgE induced by antigens. The regulation of IgE synthesis is influenced by T cells and T cell derived factors. IL -4, a T cell-derived cytokine, has been shown to stimulate murine IgE synthesis both in vitro and in vivo. Current evidence suggests that IL-4 induces IgE synthesis in the mouse by stimulating H chain isotype switch. Lipopolysaccharide (LPS) plus IL-4 cause about l00-fold increase in IgE secretion by murine B cells. The effects of PTFE on the IL-4-dependent IgE response by mouse whole spleen cells were studied. Whole spleen cells were cultured for 7 days in the presence of LPS plus IL-4 and PTFE and the supernatants were assayed for IgE. IL-4 dependent IgE production of LPS-stimulated whole spleen cells was inhibited by PTFE. Moreover, in the present study using U266Bl human IgE-bearing B cells, I found that PTFE inhibited the production of IgE activated by LPS plus IL-4. These results indicate that PTFE have antiallergic activity by inhibition of IgE production from B cells.

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A NOTE ON THE OSCILLATION CRITERIA OF SOLUTIONS TO SECOND ORDER NONLINEAR DIFFERENTIAL EQUATION

  • Kim, Yong-Ki
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제2권1호
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    • pp.53-59
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    • 1995
  • Consider a solution y(t) of the nonlinear equation (E) y" + f(t, y) = 0. A solution y(t) is said to be oscillatory if for every T > 0 there exists $t_{0}$ > T such that y($t_{0}$) = 0. Let F be the class of solutions of (E) which are indefinitely continuable to the right, i.e. y $\in$ F implies y(t) exists as a solution to (E) on some interval of the form [t$\sub$y/, $\infty$). Equation (E) is said to be oscillatory if each solution from F is oscillatory.(omitted)

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경기도(京畿道) 농촌(農村) 미취학(未就學) 아동(兒童)의 dmf 및 와동별(窩洞別) 우식분포(齲蝕分布)에 관(關)한 고찰(考察) (A Study on the dmf and distribution of dental caries in primary dentition of children living in Kyungki-do farm villages)

  • 김신
    • 대한소아치과학회지
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    • 제8권1호
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    • pp.89-102
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    • 1981
  • 1147 preschool children aged from 3 to 6 living in some farm villages in Kyungki-do were surveyed on dmf and distribution of dental caries in primary dentition. The results were as follows: 1. dmf rate ... 92.76 % boy ... 94.52 % girl ... 90.5.5 % 2. dmf t rate ... 37.07 % dmf t index ... 7.09 3. dmf s rate ... 13.74 % dmf s index ... 13.14 % 4. df t index ... 6.94 5. Each percentage of d, m & f per dmf teeth d rate ... 89.96 % m rate ... 7.24 % f rate ... 2.67 % 6. Most frequent site of dental caries in each tooth $\underline{A}$ mesial $\overline{A}$ distal $\underline{B}$ mesial $\overline{B}$ distal $\underline{C}$ distal $\overline{C}$ distal $\underline{D}$ disto-occlusal $\overline{D}$ disto-occlusal $\underline{E}$ linguo-occlusal $\overline{E}$ occlusal 7. Order of caries susceptibility $\overline{E}$ $\underline{E}$ $\overline{D}$ $\underline{D}$ $\underline{A}$ $\underline{B}$ $\overline{C}$ $\underline{C}$ $\overline{B}$ $\overline{A}$ 8. All the values in caries criteria showed a marked increae from those of 1968.

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