• 제목/요약/키워드: Q-measure

검색결과 324건 처리시간 0.025초

Experimental Study of Load Characteristics of Buried and Exposed Large-Diameter Pipelines Using Fiber-Optic Strain Sensor

  • Chung, Joseph Chul;Lee, Michael Myung-Sub;Kang, Sung Ho
    • 한국해양공학회지
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    • 제34권3호
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    • pp.194-201
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    • 2020
  • In this study, an optical-fiber sensor was used to measure loads that could act in an environment similar to the loading conditions that exist in an actual pipe. The structure and the installation method of the optical-fiber strain sensor were applied considering the actual large pipe and the buried pipe environment. Load tests were performed using a displacement sensor and sandbags to determine the deflection of the pipe according to the external load, and the linear measurement results were verified. Considering the conditions that could exist in the actual pipe, the test method was presented, and the strain of the buried pipe generated at this time was measured.

균열선단 부근의 측면함몰로부터 응력삼축성의 결정 방법 (Methods to Evaluate Stress Triaxiality from the Side Necking Near the Crack Tip)

  • 김동학;강기주
    • 대한기계학회논문집A
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    • 제28권7호
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    • pp.1021-1028
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    • 2004
  • Kim et al. suggested an experimental method to determine the Q parameter in situ from the out-of-plane displacement and the in-plane strains on the surface of side necking near the crack tip. In this paper, the procedure to evaluate the stress triaxiality near a crack tip such as the Q parameter is to be polished in the details for simplicity and accuracy. That is, Q and hydrostatic stress are determined only from the out-of-plane displacement, but not using in-plane strain, which is hard to measure. And also, the plastic modulus is determined by an alternative way. Through three-dimensional finite element analyses for a standard CT specimen with 20% side-grooves, the validities of the new procedures are examined in comparison to the old ones. The effect of location where the displacements are measured to determine the stress triaxiality is explored.

New Inchworm type Actuator with I/Q heterodyne Interferometer Feedback for a Long Stroke Precision Stage

  • Moon Chanwoo;Lee Sungho;Chung J.K
    • International Journal of Precision Engineering and Manufacturing
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    • 제6권2호
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    • pp.34-39
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    • 2005
  • The precision stage is an essential device for optic fiber assembly systems, micro machines and semiconductor equipments. A new piezoelectric inchworm type actuator is proposed to implement an actuator-integrated long-stroke linear stage. An in-and-quadrature phase (I/Q) heterodyne interferometer is developed as a feedback sensor of a servo system, and a synchronized counting method is proposed. The proposed measurement system can measure the accurate position of fast moving object with robustness to external sensing noise from actuator vibration. The developed servo stage will be applied to optic fiber device assembly system.

증권사의 정보기술투자가 기업성과에 미치는 영향에 관한 연구 (Investment in Information Technology and Performance of Securities Companies in Korea)

  • 신용재
    • 경영과정보연구
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    • 제25권
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    • pp.43-68
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    • 2008
  • From intuitional viewpoint many researchers have been considering that information technology investment serves to increase the productivity and the profitability of firm. But the empirical studies that have examined the relationship between information technology investment and firm performance have reported mixed findings. In spite of that, recently there has been growing recognition of the importance of assessing information technology investment in determining future performance of firms. This study examines the relationship between investment in information technology and performance of securities companies in Korea. I use Tobin's Q, a financial market-based measure of firm performance and investigates the pure effect of information technology investment on firm performance after controlling for a variety of firm specific variables which may affect on firm performance. This study finds that information technology investment have a significantly positive association with Tobin's Q. This result implicates that information technology investment contributes to a firm's future performance potential.

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Lebesgue-Stieltjes Measures and Differentiation of Measures

  • Jeon, Won-Kee
    • 호남수학학술지
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    • 제8권1호
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    • pp.51-74
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    • 1986
  • The thery of measure is significant in that we extend from it to the theory of integration. AS specific metric outer measures we can take Hausdorff outer measure and Lebesgue-Stieltjes outer measure connecting measure with monotone functions.([12]) The purpose of this paper is to find some properties of Lebesgue-Stieltjes measure by extending it from $R^1$ to $R^n(n{\geq}1)$ $({\S}3)$ and differentiation of the integral defined by Borel measure $({\S}4)$. If in detail, as follows. We proved that if $_n{\lambda}_{f}^{\ast}$ is Lebesgue-Stieltjes outer measure defined on a finite monotone increasing function $f:R{\rightarrow}R$ with the right continuity, then $$_n{\lambda}_{f}^{\ast}(I)=\prod_{j=1}^{n}(f(b_j)-f(a_j))$$, where $I={(x_1,...,x_n){\mid}a_j$<$x_j{\leq}b_j,\;j=1,...,n}$. (Theorem 3.6). We've reached the conclusion of an extension of Lebesgue Differentiation Theorem in the course of proving that the class of continuous function on $R^n$ with compact support is dense in $L^p(d{\mu})$ ($1{\leq$}p<$\infty$) (Proposition 2.4). That is, if f is locally $\mu$-integrable on $R^n$, then $\lim_{h\to\0}\left(\frac{1}{{\mu}(Q_x(h))}\right)\int_{Qx(h)}f\;d{\mu}=f(x)\;a.e.(\mu)$.

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물흡수선량 표준에 기반한 $^{192}Ir$ 근접치료 선원 교정 시 원통형 이온함의 이온함 간 변화 (Chamber to Chamber Variations of a Cylindrical Ionization Chamber for the Calibration of an $^{192}Ir$ Brachytherapy Source Based on an Absorbed Dose to Water Standards)

  • 김성훈;허현도;최상현;김찬형;민철희;신동오;최진호
    • 한국의학물리학회지:의학물리
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    • 제20권1호
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    • pp.7-13
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    • 2009
  • 본 논문은 물 흡수선량 표준에 기반하여 근접치료 선원인 $^{192}Ir$을 교정하는 것에 대한 예비적 연구를 위한 것이다. 이온함을 사용하여 물흡수선량 표준에 기반하여 근접치료 선원을 교정하기 위해선, 빔 선질 교정인자인 $k_{Q,Q_0}$가 필요하다. 본 연구에선 일차 표준을 사용하여 지정된 거리에서의 흡수선량를 측정하는 데 있어서의 현실적인 어려움 때문에 몬테칼로 전산모사와 반실험적인 방법을 통하여 $k_{Q,Q_0}$를 결정하였다. 본 연구를 위해 PTW30013 이온함 5개를 선택하였다. 포괄적 $k^{gen}_{Q,Q_0}$ 값의 경우엔 이온함간 변화가 최대 4.0%에 이른 반면, 개별적 $k^{ind}_{Q,Q_0}$ 경우엔 이온함간 변화가 최대 0.5% 이내였다. 이 결과는 물 흡수선량에 기반하여 근접치료 선원인 $^{192}Ir$을 교정시에 이온함을 왜 개별적으로 교정해야 하는지, 개별적인 교정이 얼마나 중요한 지를 보여 준다. 가까운 장래에 공기커마 세기 대신에 사용자가 근접치료 선원을 고에너지 광자빔과 전자빔의 교정에서처럼 치료에서 관심있는 물리량인 물흡수선량의 관점에서 교정할 수 있기를 희망한다.

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간호학생의 임상실습 스트레스 경험유형 : Q방법론적 접근 (Stress Experience of Nursing Students to Clinical Practice : Q-methodological Approach)

  • 장혜숙;김순애;김흥규
    • Child Health Nursing Research
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    • 제5권1호
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    • pp.5-17
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    • 1999
  • This study was designed to determine the schemata and their characteristics of stress experience the subjectivity of stress experience(structure of subjectivity) would be a basic step for the effective clinical education through the stress management for characteristics of these types. Q-methodological method was used for that purpose. The research method statements were collected prior to the study through indepth interviews. For the study, 31 Q-statements were selected. There were 34 nursing students as subjects for the research. The 34 nursing students sorted the 31 statements using the principal of forced normal distribution. The principle of forced normal distribution, which has 9 scales to measure the individual opinions, was called. Q-factor analysis by using PC QUANL program supply the material. According to the outcomes of this study, there were 3 types of special opinion about the stress experience of clinical practice. The first type is called 'Influence of practical atmosphere type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The second type is called 'conflict of nursing role type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The third type is called 'Lack of confidence type'. Members of this type experienced stress because of a lack of confidence for their own nursing knowledge and skill. As a result, we now need further study to identify individual psychological aspects of stress for clinical practice. The findings will guide the development in effective approaches for clinical education. Finally, the result of the study will provide us the need for developing systematic and integrated practice education program for students and active involvement of clinical instructor.

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회계투명성과 CSR이 재무적 성과와 기업가치에 미치는 영향 (An Empirical Study on the Effect of Transparency and CSR On Financial Performance and Firm Value)

  • 오상희
    • 경영과정보연구
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    • 제31권3호
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    • pp.117-139
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    • 2012
  • 본 연구의 목적은 회계투명성과 기업의 사회적 책임이 재무성과 및 기업가치와의 관련성을 살펴보는 것이다. 그러나 우리나라에서는 사회적 책임에 관한 지표가 보편타당한 것이 아니라 특정 연구소에서 조사하고 있는 지표를 주로 사용하고 있기 때문에 보다 신뢰성 있는 연구를 위해, 먼저 선행연구에서 연구된 결과들을 바탕으로 기업의 투명성 변수를 살펴본 뒤 그 연구를 기반으로 사회적 책임과 재무성과 및 기업가치와의 관련성을 살펴보고자 한다. 본 연구의 분석결과를 요약하면 다음과 같다. 첫째, 종속변수가 ROA인 경우 자산의 질(QAS) 변수만 제외하고 모두 유의적인 관련성을 나타내었고, 종속변수를 Tobin's Q로 한 분석에서는 매출액순이익률(CITSA), 매출채권비율(SCTSA), 판매관리비비율(SETR) 그리고 매출액성장율(SATSA)이 유의적인 관련성을 보였다. 따라서 가설 1은 모든 변수는 아니지만 부분적으로는 받아들여졌다. 둘째, 가설 2와 3의 검증을 위해 투명성 변수에 따라 모형을 4가지로 나누어 분석한 결과, '전체-ROA'와 'ROA'모형 그리고 '전체-Tobin's Q'와 'Tobin's Q' 모형에서도 lnCSR과 TranD${\times}$lnCSR이 유의적인 양(+)의 관계를 나타내어 가설 2와 가설 3이 받아들여졌다. 본 연구의 차별점은 지금까지 거의 연구가 이루어지지 않았던 기업의 사회적 책임과 회계투명성을 연결시켜 기업의 사회적 책임과 투명성 그리고 기업가치와 관련성을 분석하였다는 점과, 발표되지 않는 자료를 포함하여(약 360개 기업) 표본을 확장하여 연구를 일반화하였다는 점을 들 수 있다.

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반도체 제조장비의 particle/gas 측정ㆍ분석 시스템 (Measuring and Diagnostic System for particle and gas in Semiconductor Equipment)

  • 황희융;설용태;임효재;차옥환;이희환
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2002년도 추계학술발표논문집
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    • pp.178-180
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    • 2002
  • In this Paper, we conducted a experimental study to measure a particle size distribution and mass spectrum with the special instrument such as ISPM and Q-MS. Also, we set up a total measuring system for monitoring the particle in the process chamber.

흡연행위 예측을 위한 대학생의 태도 분석 (An Analysis on Attitudes of University Students in the Prediction of Smoking Behavior)

  • 정향미
    • Child Health Nursing Research
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    • 제4권1호
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    • pp.128-149
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    • 1998
  • Cigarette smoking has been identified as the single most important source of preventable morbidity and mortality. Smoking behavior varies each individual, so individuality & subjectivity of smoking behavior must be specially focused upon to understand smoking behavior. The purpose of this study was to find attitudes of university students in the prediction of smoking behavior. Q-Methodological method was used as a research design and data were collected during the period from Jan.1, 1997 to Feb. 28, 1998. As the research method, Q-statements were collected through in- depth interviews and a literature review. For the study 33 Q-statements were selected. There were 45 university students as subjects for the research. The 45 university students sorted the 33 statements using the principle of Forced Normal Distribution. The principle of Forced Normal Distribution, which has nine scales to measure the individual opinions, Pc Quanl program was used for analysis and Q-factors were analyzed by using principal component analysis. According to the results of this study, there were four categories of opinion about the smoking behavior in university students. The first type is seeking the habitual dependency. The second type is seeking the stress relief : The third type is seeking the active disapproval : The fourth type is seeking the self control. As a result, The meaning of the smoking behavior is affected by perceived subjective experience, so we need to understand each persons meaning of the smoking behavior and to develop appropriate nursing interventions based on the typology of smoking behavior. Finally, The result of the study will provide basic data for smoking prevention and cessation program.

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