• 대한기계학회논문집
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• 제19권10호
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• pp.2678-2689
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• 1995

In this study, a new hot-wire anemometer which has greater sensitivity than that of a constant temperature anemometer (CTA) was proposed. In contrast to CTA, the wire working resistance of the new anemometer increases with flow velocity, that is, the operating mode of the wire becomes variable temperature. The variable temperature anemometer(VTA) was made by substituting a voltage controlled variable resistor such as photoconductive cell or transistor for one of the resistors in the bridge. By positively feeding back the bridge top signal to the input side of these electronic components, the wire overheat ratio could be increased with velocity automatically. Static response analyses of the VTA, constant voltage anemometer (CVA) and CTA were made in detail and calibration experiments were performed to validate the proposed operating principle. The wire operating resistance of the CVA decreases with velocity and this leads to lower sensitivity than that of a CTA. But the sensitivity of the newly proposed VTA is superior to that of a CTA, since the wire overheat ratio increases with velocity. Consequently, it is found that the major factor that is responsible for large sensitivity of a VTA is not the working resistance itself but the change of the wire working resistance with velocity.

• 한국보육학회지
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• 제19권1호
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• pp.101-115
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• 2019

본 연구의 목적은 영아교사의 교수효능감과 민감성이 조직몰입에 미치는 영향을 알아보는 것이다. 연구대상은 S지역의 어린이집 영아교사 206명이다. 본 연구에서는 곽희경(2011)이 사용한 교수효능감 도구, 민광미(2014)가 개발한 교사 민감성 척도, 이종각(2013)이 수정, 보완한 조직몰입 검사 도구를 사용하여 설문조사를 하였다. 수집된 자료는 SPSS 21.0 Win program을 사용하여 신뢰도 분석, 기술통계, 상관분석, 중다회귀분석을 실시하였다. 연구결과, 첫째, 영아교사의 교수효능감은 보통 수준이었으며, 민감성은 보통보다 높은 수준이었고, 조직몰입은 보통 수준보다 약간 높은 것으로 나타났다. 둘째, 영아교사의 일반적 교수효능감은 모든 조직몰입과 정적관계를 보였고, 민감성은 조직몰입 중 정의적 몰입과 규범적 몰입에 정적관계를 나타냈다. 셋째, 영아교사의 조직몰입에 교수효능감의 하위요인 중 일반적 효능감, 민감성의 하위요인 중 일관성이 영향력 있는 변인으로 나타났다. 본 연구의 결과는 영아교사의 조직몰입 향상에 교사의 내적요인인 교수효능감과 민감성이 중요함을 시사하였다.

• Steel and Composite Structures
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• 제15권5호
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• pp.567-583
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• 2013

Experimental studies and finite element analyses have been carried out to establish the effect of tendon damage on the structural behavior of concrete filled tubular tied arch girder (CFTA girder). The damage of tendon is considered in different stages by varying the number of damaged cables in the tendon. Static and dynamic structural parameters are observed at each stage. The results obtained from the experiments and numerical studies have been compared to validate the studies. The tendons whose damage can significantly affect the stiffness of the CFTA girder are identified by performing the sensitivity analysis. The locations in the girder which are sensitive to the tendon damage are also identified.

• 대한기계학회논문집A
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• 제29권8호
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• pp.1061-1069
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• 2005

In part I of this papter Nonlinear Response Optimization using Equivalent Static Loads (NROESL) method/algorithm is developed to conduct optimization for nonlinear behavior structures. The method/algorithm is also verified to show its convergency and optimality. In this present paper, the NROESL algorithm is applied to several structural problems with geometric and/or material nonlinearity. Conventional optimization with sensitivity analysis using the finite difference method is also applied to the same examples. The results of the optimizations are compared. The proposed method is very efficient and derives good solutions.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.135-142
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• 1999

Plate girder bridges for tile Korean high-speed railway are optimally designed. Static and dynamic constraints are all considered. The design variables are the thicknesses and the lengths of the plates that are used to form I-shaped main girders with variable cross-sections. And the objective function is tile steel weight of a main girder. A C++ based design program is developed; this program interfaces with a FORTRAN based optimization program ADS. From the results of optimal design for various span lengths, it is observed that the deck vertical acceleration is one of the most important constraints in a special range of tile span length. Front a parametric study, sensitivity of the optimal design to static as well as dynamic constraints are presented.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.508-513
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• 1997

One of the moot important constants to be Installed In COLSS, a monitoring system in CE typed reactors, is ROPM which would limit the operating space. This static ROPM was calculated from digital transient analysis assuming that every design basis transient was initiated from the most severe initial condition combination (LCO). Once It could be assured that core condition would not be located at none other than LCO, this static ROPM could be replaced with dynamic ROPM calculated at that condition and the dynamic ROPM would be definitely less than the static ROPM. In order to do, It must be required to calculate the transient discrete sensitivity parameters and parameters change distribution. The purpose of this report is just to propose the enlargement method for thermal margin.

• 가정과삶의질연구
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• 제32권5호
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• pp.193-205
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• 2014

The purpose of this research is to gather basic data to make nursery teachers' role clear and to suggest a way to improve their expertise by investigating their sensitivity and expertise. To fulfill this aim, this research was performed by targeting 180 nursery teachers responsible for infant classes in national, public, and private nursery schools. To measure the nursery teachers' sensitivity, Gerber's (2003) teacher sensitivity indicator is used. And to measure the efficacy of teaching play, the indicator, which was developed by E. Shin, Y. Yu and H. Park (2004), was used through modification and complement. Also for measuring the teacher's expertise, research data were collected by the generalized and modified questionnaire which was used in H. Yoon's (2010) research. The results of the analysis of collected data show that the teacher group with higher sensitivity in the infant class shows meaningfully higher professional ethics, higher performance, and higher recognition of expertise than the teacher group with lower sensitivity. And the teacher group with higher awareness of the efficacy of play shows higher professional ethics, higher performance, and higher recognition of expertise than the teacher group with lower sensitivity. too. Also, the results of the analysis of the correlation between the infant teacher's sensitivity, efficacy of teaching play, and recognition of expertise show that the teacher's sensitivity has a static correlation with the total points of social necessity, professional ethics, fairness, teacher's performance, and recognition of expertise. When we generalize the research results, we find that positive sensitivity and higher efficacy of teaching play make the infant class teacher's expertise recognition higher.

• 한국화재소방학회논문지
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• 제24권5호
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• pp.102-106
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• 2010

본 논문은 실내사격장 화재 원인에 대한 조사를 위하여 권총 사용에 따른 화약잔사 양에 대한 실측 및 발화특성에 관하여 연구하였다. 화약잔사 양은 구경 0.38인치 권총 및 구경 9mm 권총을 사용하였으며, 사대 및 바닥면에 떨어지는 화약잔사를 측정하였다. 화약잔사에 대한 발화특성 평가를 위하여 충격감도, 정전기감도, 마찰감도 및 발화점 시험을 실시하였으며, 비교 평가에는 권총에 일반적으로 사용되는 사용전의 화약(ball powder)을 이용하여 화약잔사와 동일한 시험을 실시하였다. 실험결과 충격감도 및 마찰감도는 화약잔사에서 다소 높게 측정되었으며, 발화점 시험에서는 화약잔사가 비교대상인 사용전의 화약에 비해 낮은 온도에서 발화되는 특성을 나타내었다.

• 센서학회지
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• 제6권3호
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• pp.180-187
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• 1997

We demonstrate the improvement of sensitivity and analysis of operating characteristics of the piezoelectric pressure sensor using ZnO piezoelectric thin film and FET(field effect transistor) for sensing applied pressure and transforming the pressure into electrical signals, respectively. The sensitivity of the PSFET(pressure sensitive field effect transistor) was improved by using highly-oriented ZnO film perpendicular to the substrate surface and the operating characteristics was investigated by monitoring output voltage with time in various static pressure levels.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 전문대학교육위원 P
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• pp.52-55
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• 1999

In recent years, much attention has been paid to the voltage collapse phenomena. There has been reported many cases about the voltage collapse in many countries. These voltage collapse phenomena are known as the event that can occur due to reactive power deficits. This paper proposes an efficient method that can pursue the reactive power loss changes and gives the simple voltage collapse proximity indicator(VCPI) based on the reactive power loss sensitivities using optimal techniques. By comparing reactive power loss sensitivity with active power loss sensitivity, it is also proved that VCPI based on reactive power loss sensitivities is more effective. The developed VCPI is derived from the Jacobian matrix of Load Flow and the computational burden is very low and on-line implementation is possible. The proposed method is applied to a IEEE-14 bus test system and reliable and promising results are obtained.