• 제목/요약/키워드: X-factor

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X선영상증배관의 상대변환계수 측정에 관한 검토 (The Study on Measurement of Relative Conversion Factor in X-ray Image Intensifier)

  • 김성철;신성일;이선숙;허준;김성수
    • 대한방사선기술학회지:방사선기술과학
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    • 제20권2호
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    • pp.28-33
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    • 1997
  • For the Evaluation of X-ray image intensifier, we measured radiation dose at input of I. I., brightness and fluorescence at output of I. I. by using X-ray exposure meter, optometer and fluorescence meter for the relative conversion factor. Especially, by using fluorescence meter, we could easily get relative conversion factor without having regulated machine by JIS. Since using, the quality of image intensifier is going down. Consequently, it needs continuous quality maintenance.

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열전재료 Zn1-xAgxSb의 제조와 특성 (Synthesis and characterization of thermoelectric Zn1-xAgxSb compounds)

  • 김인기;오한준;장경욱
    • 한국결정성장학회지
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    • 제27권4호
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    • pp.162-166
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    • 2017
  • $Zn_{1-x}Ag_xSb$에서 Ag의 함량이 0~0.2인 열전화합물을 진공용해법으로 제조하여 결정상과 열전물성을 조사하였다. x = 0.05에서는 금속성 free Sb 상이 많이 생성되었고 이로 인해 전기전도도와 power factor가 크게 증가하였고 power factor는 제벡계수보다는 전기전도도에 의해 더 큰 영향을 받았다. x = 0.1 이상에서는 $Ag_3Sb$ 상이 현저하게 늘어났고 free Sb 피크는 약화되었다. 이에 따라 전기전도도와 power factor는 감소하기 시작하였고 이러한 경향은 더 많은 Ag가 첨가되면서 더욱 뚜렷하게 나타났다.

저녹스 버너 설치 시설의 질소산화물 저감 효율 산정 방법 (The Methods Calculating the Reduction Efficiency of Nitrogen Oxide for the Facilities Including the Low NOx Burners)

  • 이기용
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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    • pp.295-296
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    • 2015
  • We presented the methods calculating the reduction efficiency of nitrogen oxide for the low $NO_x$ burner as the pollution prevention facilities. The standard $NO_x$ concentration was used on the emission factor of LNG, $3.7g/m^3$. The $NO_x$ reduction efficiency based on the $NO_x$ concentration was presented and the relationships between the $NO_x$ concentration and the emission factor or the specific heat emission factor were derived. These results could be accurately reflected on calculating the amount of the nitrogen oxide emissions. In addition, according to the arrangement of the low $NO_x$ burners the methods of applying their $NO_x$ reduction efficiency were proposed. The $NO_x$ reduction efficiency for the facilities consisting of the low $NO_x$ burners and the non-low $NO_x$ burners could be estimated with information about the reduction efficiency of each low $NO_x$ burners, the fuel consumption rate, and the heating value of fuel.

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(Pb1-1.5xLax)(Ti1-yMny)O3계의 유전 및 압전성질 (The Dielectric and Piezoelectric Properties of (Pb1-1.5xLax)(Ti1-yMny) System)

  • 맹성재;정형진
    • 한국세라믹학회지
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    • 제25권4호
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    • pp.321-328
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    • 1988
  • The sintering phenomena, electrical resistivity, dielectric and piezoelectric properties of lead titanate ceramics modified by the partial substitution of La for Pb and Mn for Ti, (Pb1-1.5xLax)(Ti1-yMny)O3 ceramics, have been investigated. In (Pb1-1.5xLax)(Ti1-yMny)O3 system, with increasing lanthanum content, the realtive bulk density increased, but the Curie point and tetragonality (c/a) decreased. The tetragonal-to-cubic phase transition boundary existed in the range of 0.20

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Factor Rank and Its Preservers of Integer Matrices

  • Song, Seok-Zun;Kang, Kyung-Tae
    • Kyungpook Mathematical Journal
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    • 제46권4호
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    • pp.581-589
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    • 2006
  • We characterize the linear operators which preserve the factor rank of integer matrices. That is, if $\mathcal{M}$ is the set of all $m{\times}n$ matrices with entries in the integers and min($m,n$) > 1, then a linear operator T on $\mathcal{M}$ preserves the factor rank of all matrices in $\mathcal{M}$ if and only if T has the form either T(X) = UXV for all $X{\in}\mathcal{M}$, or $m=n$ and T(X)=$UX^tV$ for all $X{\in}\mathcal{M}$, where U and V are suitable nonsingular integer matrices. Other characterizations of factor rank-preservers of integer matrices are also given.

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Development of a Highly Active Fluorescence-Based Detector for Yeast G Protein-Coupled Receptor Ste2p

  • Hong, Jin Woo;Ahn, Hee Jun;Baek, Jee Su;Hong, Eun young;Jin, Dong Hoon;Khang, Yong Ho;Hong, Nam Joo
    • Journal of Microbiology and Biotechnology
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    • 제28권10호
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    • pp.1589-1603
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    • 2018
  • Twenty analogs of $[Orn^6,D-Ala^9]{\alpha}-factor$ were synthesized and assayed for their biological activities: seven analogs of $[Orn^6,X^9]{\alpha}-factor$, seven analogs of $[X^6,D-Ala^9]{\alpha}-factor$, five analogs of $[X^5,X^6,D-Ala^9]{\alpha}-factor$, and native ${\alpha}-factor$ (X = amino acids). Their biological activities (halo, gene induction, and affinity) were measured using S. cerevisiae Y7925 and LM102 and compared with those of native ${\alpha}-factor$ (100%). G protein-coupled receptor was expressed in strain LM102 containing pESC-LEU-STE2 vector. $[Dap^6,D-Ala^9]{\alpha}-factor$ with weak halo activity (10%) showed the highest receptor affinity (> 230%) and the highest gene induction activity (167%). $[Arg^6,D-Ala^9]{\alpha}-factor$ showed the highest halo activity (2,000%). The number of active binding sites per cell (about 20,000 for strain LM102) was determined using a newly-designed fluorescence-based detector, $[Arg^6,D-Ala^9]{\alpha}-factor-Edan$, with high sensitivity (12,500-fold higher than the absorption-based detector $[Orn^6]{\alpha}-factor-[Cys]_3$).

(1-x)ZnWO4-xTiO2 세라믹스의 마이크로파 유전특성 (Microwave Dielectric Properties of (1-x)ZnWO4-xTiO2 Ceramics)

  • 윤상옥;김대민;심상흥;강기성
    • 한국전기전자재료학회논문지
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    • 제16권5호
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    • pp.397-403
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    • 2003
  • Microwave dielectric properties of (1-x)ZnW $O_4$-xTi $O_2$ ceramic systems were investigated with calcination temperatures and Ti $O_2$ contents. The ZnW $O_4$ ceramic could be suitably sintered at 1075$^{\circ}C$ and showed the dielectric constant of 13.6, quality factor(Q$\times$ $f_{O}$value) of 22,000 and temperature coefficient of resonant frequency($\tau$$_{f}$) of -65$\pm$2ppm/$^{\circ}C$. Increasing the amount of Ti $O_2$ in the range of 0.25 to 0.45 mol, the dielectric constant and $\tau$$_{f}$ increased due to the role of Ti $O_2$ but the quality factor decreased due to the increase of phase boundaries. The 0.7ZnW $O_4$-0.3Ti $O_2$ ceramic showed the dielectric constant of 19.8, qualify factor(Q$\times$ $f_{0}$) of 20,000 and $\tau$$_{f}$ of -3$\pm$1ppm/$^{\circ}C$.>.EX>.>.>.

고정 지점을 갖는 X-브레이싱의 탄성 면외 좌굴 (Out-of-Plane Elastic Buckling of X-Bracing System with Fixed Ends)

  • 문지호;윤기용;이학은
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2007년도 정기총회 및 학술발표대회
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    • pp.293-296
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    • 2007
  • This study investigated the out-of-plane elastic buckling load and effective length factor of X-bracing system. The members of X-bracing system which are studied in this paper are rigidly attached to the structure at their end connections, and are pinned or rigidly connected at their point of intersection. The effective length factors are derived for the general case where the tension and compression brace have different material and geometrical properties.

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Target Transformation Factor Analysis에 의한 겹침 X-선 형광 스펙트라의 정량적 해석 (A Quantitative Interpretation of the Overlapped X-Ray Fluorescence Spectra by Target Transformation Factor Analysis)

  • 김승원;이철;최상원;강형태
    • 대한화학회지
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    • 제36권5호
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    • pp.720-726
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    • 1992
  • 겹쳐 나타나는 X-선 형광 스펙트라에서 얻은 다변수 데이타를 해석하기 위하여 다변수분석법인 인자분석법을 적용하였다. Pb와 As의 피크가 겹쳐 있는 11개 표준시료의 X-선 형광 스펙트라를 파장분산형기기로 $33.50∼34.50^{\circ}$에서 측정하였다. 8개 시료의 피크세기로 데이타 매트릭스를 구성하고 AFA(Abstract Factor Analysis)를 수행하였다. 그 결과 인자의 수가 3으로 나타났으며 표준시료에 함유된 8개 원소를 타겟트 테스트한 결과 Pb, As 및 Cu로 판명되었다. 농도 기지인 시험시료에서 상기 원소들의 농도를 피크의 겹침에 무관하게 TTFA(Target Transformation Factor Analysis)에 의해 결정하였다.

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($Ba_{1-x}Sr_{x}$)O-$Sm_2O_3$-$TiO_2$세라믹스의 마이크로파 유전특성 (Microwave Dielectric Properties of the ($Ba_{1-x}Sr_{x}$)O-$Sm_2O_3$-$TiO_2$ Ceramics.)

  • 박인길;류기원;배선기;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 추계학술대회 논문집
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    • pp.5.2-8
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    • 1995
  • 0.15($Ba_{1-x}Sr_{x}$)O-$0.15Sm_2O_3$-$0.7TiO_2$(x=0∼9[m/o]ceramics were fabricated by mixed-oxide method. Microwave dielectric properties were investigated with sintering conditions aid Sr addictive. In the specimen with x=0[m/o] sintered at 1350∼1470[$^{\circ}C$], dielectric constant, quality factor and temperature coefficient of resonant frequency were 70∼74, 2800∼3300(at 3[GHz]), -1.33∼+l.66[ppm/$^{\circ}C$, respectively. Increasing the Sr additive from 0 to 5[m/o], dielectric constant and temperature coefficient of resonant frequency were increased and quality factor was decreased. In the specimen with x=r[m/o] sintered at 1375[$^{\circ}C$], 6[hr], dielectric constant, quality factor and temperature coefficient resonant frequency were 75.62, 2785(at 3[GHz]), +8.39[ppm/$^{\circ}C$], respectively.