• 제목/요약/키워드: gamma transformation

검색결과 182건 처리시간 0.026초

Fe-Mn 합금의 γ→ε 마르텐사이트변태에 필요한 구동력 (Driving Forces for γ→ε Martensitic Transformation of Fe-Mn Alloys)

  • 이영국;최종술
    • 열처리공학회지
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    • 제9권4호
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    • pp.243-251
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    • 1996
  • Dilatometric experiment and thermodynamic calculation have been performed to determine $M_s$, $A_s$ and driving forces for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation of Fe-Mn alloys. The transformation temperatures($M_s$, $A_s$, $T_o) were decreased with increasing manganese content and were newly formulated as a function of manganese content. Driving force for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation was increased from -75J/mole to -105J/mole with increasing manganese content from 15wt.% to 25wt.%. Transformation temperature hysteresis($A_s-M_s$) was also increased from 50K to 80K with increasing mangenese content from 15wt.% to 25wt.%. The small driving force(-75J/mole~-105J/mole) and small ${\Delta}T$(50K~80K) for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation indicated that Fe-Mn alloys behave like thermoelastic martensitic alloys : We would like to call them semi-thermoelastic martensitic alloys.

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와류탐상에 의한 금속의 변태율 측정 (Eddy Current Testing to Measure Transformation Ratios in Metal)

  • 위상봉;한민구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.824-827
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    • 1988
  • Eddy Current Sensor to Measure the ${\gamma}-{\alpha}$/ Transformation Ratio of Metal is Designed and Implemented. Experimental Results Regarding to Impedance Variation due to ${\gamma}-{\alpha}$ Transformation Ratio of Metal Under Room Temperature are Reported. It Was Found That the Impedance of Metal is Increased With Increasing ${\gamma}-{\alpha}$ Ratio.

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감마변환을 사용한 히스토그램 평활화 (Histogram Equalization using Gamma Transformation)

  • 정소영;정민교
    • 정보과학회 컴퓨팅의 실제 논문지
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    • 제20권12호
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    • pp.646-651
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    • 2014
  • 히스토그램 평활화는 영상의 밝기 값 분포가 한 곳에 밀집되어 있는 경우, 출력영상의 밝기 값 범위가 지나치게 확장되어 시각적으로 부자연스러운 결과를 초래하는 단점을 가지고 있다. 그런데 감마변환은 이런 부자연스러운 현상을 비선형적 변환을 통해 보정해주는 성질을 가지고 있다. 따라서 본 논문에서는 감마변환의 이런 성질을 이용하여 영상의 화질을 개선하는 새로운 히스토그램 평활화 방법을 제안한다. 제안 방법은 먼저, 입력영상의 평균 밝기 값을 이용하여 적절한 감마변환 식을 도출하고, 입력영상의 CDF(Cumulative Distribution Function)를 도출된 감마변환 식과 선형 결합하여 새로운 CDF를 생성한 후, 새롭게 변형된 CDF를 사용하여 히스토그램 평활화를 수행한다. 실험결과 제안방법이 기존방법들에 비해 entropy, UIQ, SSIM 등과 같은 정량적 평가에서 좋은 성능을 보였고, 시각적 관점에서도 자연스럽게 화질을 개선하였다.

${\gamma}-Poly(glutamic\;acid)$ 생산성 균주 Bacillus licheniformis 9945a의 형질전환 미 돌연변이 유도 (Transformation and Mutation of Bacillus licheniformis 9945a Producing ${\gamma}-Poly(glutamic\;acid)$)

  • 정완석;고영환
    • Applied Biological Chemistry
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    • 제40권3호
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    • pp.173-177
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    • 1997
  • Bacillus licheniformis 9945a는 액체배양시 ${\gamma}-poly(glutamic\;acid)$를 균체외로 분비하며, 한천배지에 고체 배양시는 점액질의 군락을 나타낸다. 점액질의 Bacillus속 세균의 형질전환은 그리 순하지 않은 것으로 알려져 있으며, B. licheniformis에서의 trasposon Tn10의 활성여부도 알려져 있지 않다. 그래서 점액질을 분비하지 않는, B. licheniformis의 자연발생적 변이주를 우선 분리하였다. Mini-Tn10을 함유한 plasmid pHV1248을 protoplast transformation법에 준해서 이 변이주에 도입하여 형질전환체를 분리하였다. pHV1248을 함유한 형질전환체를 점액성의 야생형질로 복귀시킨 후에, 가열처리함으로써 무작위 돌연변이를 유도하였다. Arginine, lysine 또는 tryptohan을 생육인자로 요구하는 돌연변이주들이 replica plating method에 의해서 분리되었고, 이 들 영양요구성 변이주는 mini-Tn10이 염색체 DNA상에 삽입됨으로써 생겨났음이 Southern blotting과 DNA-DNA 혼성화 실험으로 증명되었다. 이러한 pHV1248을 이용한 형질전환 및 돌연변이 유도방법은 Bacillus licheniformis 9945a의 다양한 변이체를 얻는데 유용할 것이다.

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OSCILLATION OF SECOND ORDER SUBLINEAR NEUTRAL DELAY DYNAMIC EQUATIONS VIA RICCATI TRANSFORMATION

  • SETHI, ABHAY KUMAR
    • Journal of applied mathematics & informatics
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    • 제36권3_4호
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    • pp.213-229
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    • 2018
  • In this work, we establish oscillation of the second order sublinear neutral delay dynamic equations of the form:$$(r(t)((x(t)+p(t)x({\tau}(t)))^{\Delta})^{\gamma})^{\Delta}+q(t)x^{\gamma}({\alpha}(t))+v(t)x^{\gamma}({\eta}(t))=0$$ on a time scale T by means of Riccati transformation technique, under the assumptions $${\displaystyle\smashmargin{2}{\int\nolimits^{\infty}}_{t_0}}\({\frac{1}{r(t)}}\)^{\frac{1}{\gamma}}{\Delta}t={\infty}$$, and ${\displaystyle\smashmargin{2}{\int\nolimits^{\infty}}_{t_0}}\({\frac{1}{r(t)}}\)^{\frac{1}{\gamma}}{\Delta}t$ < ${\infty}$, for various ranges of p(t), where 0 < ${\gamma}{\leq}1$ is a quotient of odd positive integers.

變態二酸化 망간의 分析化學的 硏究 (第二報). 示差熱曲線에 依한 ${\gamma}-MnO_2$의 定量法 (The Study of Analytical Chemistry of the Modification of Manganese Dioxide (Report Two). Quantitative Determination of ${\gamma}$-Manganese Dioxide by Differential Heating Curves)

  • 김찬호
    • 대한화학회지
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    • 제15권5호
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    • pp.241-245
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    • 1971
  • ${\gamma}-MnO_2$는 示差熱曲線에서 結晶變移의 吸熱 peak가 明白하게 나타났으며 他變態의 轉移溫度 와 相異하였다. 本 peak를 利用하여 半面積法으로 ${\gamma}-MnO_2$만의 定量分析을 檢討하였다. 相對誤差 ${\pm}$5%範圍內에서 試料 50mg∼300mg까지 定量할 수 있었다. ${\alpha},{$beta}-MnO_2$ (pyrolusite)가 妨害物質로서 約 75%까지 混合될경우에도 相對誤差는 ${\pm}$10%程度였으며 約 50%以內가 混合될 경우에는 相對誤差 ${\pm}$5%以內로서 거의 영향이 없었다.

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On the Properties of $\gamma$-.$\varepsilon$ for $H_\infty$ Control by State Feedback and Computation of the Infimum of $H_\infty$ Norm

  • Tian, Dong;Ohta, Michio
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.562-565
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    • 1993
  • It is well known that H$_{\infty}$ control problem involves solving an algebraic Riccati equation which includes a pair of parameters (.gamma., .epsilon.). Focusing on .epsilon. the maximum of .epsilon.. We discuss in this paper about the properties between the H$_{\infty}$ norm of a trnsfer function matrix and the parameters(.gamma., .epsilon.). We can change the algebraic relattion between .gamma. and .epsilon. by the similarity transformation of a considered system and we can find a proper transformation to get a simple quadratic algebraic equation between .gamma. and .epsilon.. This relation provide the H$_{\infty}$ norm of a transfer function.on.

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A Control Chart for Gamma Distribution using Multiple Dependent State Sampling

  • Aslam, Muhammad;Arif, Osama-H.;Jun, Chi-Hyuck
    • Industrial Engineering and Management Systems
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    • 제16권1호
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    • pp.109-117
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    • 2017
  • In this article, a control chart based on multiple dependent (or deferred) state sampling for the gamma distributed quality characteristic is proposed using the gamma to normal transformation. The proposed control chart has two pairs of control limits, which can be determined by considering the in-control average run length (ARL). The shift in the scale parameter of a gamma distribution is considered and the out-of-control ARL is evaluated. The performance of the proposed chart has been shown for different levels of the parameters of the proposed control chart. It is also shown that the proposed chart is better than the Shewhart chart in terms of ARLs. A case study with a real data has been included for the practical usage of the proposed scheme.

RICCATI TRANSFORMATION AND SUBLINEAR OSCILLATION FOR SECOND ORDER NEUTRAL DELAY DYNAMIC EQUATIONS

  • Tripathy, Arun Kumar
    • Journal of applied mathematics & informatics
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    • 제30권5_6호
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    • pp.1005-1021
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    • 2012
  • This work is concerned with oscillation of the second order sublinear neutral delay dynamic equations of the form $$\(r(t)\;\((y(t)+p(t)y(a(t)))^{\Delta}\)^{\gamma}\)^{\Delta}+q(t)y^{\gamma}({\beta}(t))=0$$ on a time scale $\mathcal{T}$ by means of Riccati transformation technique, under the assumptions $\int^{\infty}_{t_0}\(\frac{1}{r(t)}\)^{\frac{1}{\gamma}}$ ${\Delta}t={\infty}$ and $\int^{\infty}_{t_0}\(\frac{1}{r(t)}\)^{\frac{1}{\gamma}}$ ${\Delta}t$ < ${\infty}$, where 0 < ${\gamma}{\leq}1$ is a quotient of odd positive integers.

Resveratrol enhances cisplatin-induced apoptosis in human hepatoma cells via glutamine metabolism inhibition

  • Liu, Zhaoyuan;Peng, Qing;Li, Yang;Gao, Yi
    • BMB Reports
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    • 제51권9호
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    • pp.474-479
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    • 2018
  • Cisplatin is one of the most effective chemotherapeutic drugs used in the treatment of HCC, but many patients will ultimately relapse with cisplatin-resistant disease. Used in combination with cisplatin, resveratrol has synergistic effect of increasing chemosensitivity of cisplatin in various cancer cells. However, the mechanisms of resveratrol enhancing cisplatin-induced toxicity have not been well characterized. Our study showed that resveratrol enhances cisplatin toxicity in human hepatoma cells via an apoptosis-dependent mechanism. Further studies reveal that resveratrol decreases the absorption of glutamine and glutathione content by reducing the expression of glutamine transporter ASCT2. Flow cytometric analyses demonstrate that resveratrol and cisplatin combined treatment leads to a significant increase in ROS production compared to resveratrol or cisplatin treated hepatoma cells alone. Phosphorylated H2AX (${\gamma}H2AX$) foci assay demonstrate that both resveratrol and cisplatin treatment result in a significant increase of ${\gamma}H2AX$ foci in hepatoma cells, and the resveratrol and cisplatin combined treatment results in much more ${\gamma}H2AX$ foci formation than either resveratrol or cisplatin treatment alone. Furthermore, our studies show that over-expression of ASCT2 can attenuate cisplatin-induced ROS production, ${\gamma}H2AX$ foci formation and apoptosis in human hepatoma cells. Collectively, our studies suggest resveratrol may sensitize human hepatoma cells to cisplatin chemotherapy via gluta${\gamma}H2AX$mine metabolism inhibition.