• 제목/요약/키워드: moment measure

검색결과 259건 처리시간 0.025초

예비유아교사의 긍정심리와 리더십과의 관계 (The Relation between the Positive Psychology of Would-be Child Teachers and Leadership)

  • 장정백;이미나
    • 한국지역사회생활과학회지
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    • 제23권4호
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    • pp.491-499
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    • 2012
  • This research is looking for the relation between the positive psychology of would-be child teachers and leadership and that's influence. The researchers examined positive psychology and leadership with 330 would-be teachers(13 boys, 317 girls) located in Gwang-Ju and the Jeonnam Region. Questionnaire was used to measure would-be teachers. The collected data analyzed the positive psychology of would-be teachers and leaders, including sub-factors for mean(M), standard deviation(SD) and Pearson product-moment correlation according to subject for inquiry. Then regression analysis through SPSS WIN 17.0 for checking the effects of the would-be child teachers's positive psychology with their leadership skill was used. The result of the research was that the positive psychology of would-be child teachers and leadership of the product-moment correlated in all areas. Especially the most influence on positive psychology is the ability of human relationship among leadership sub-variables, and the relation between positive psychology and leadership are very important for making positive changes in society. This implies that there is a need for more educational sponsorship regarding positive psychology and leadership for would-be child teachers.

손가락 힘센서를 가진 지능형 로봇손 개발 (Development of Intelligent robot' hand with Three Finger Force Sensors)

  • 김갑순;신희준;김현민
    • 한국정밀공학회지
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    • 제26권1호
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    • pp.89-96
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    • 2009
  • This paper describes the intelligent robot's hand with three finger sensors for a humanoid robot. In order to grasp an unknown object safely, the intelligent robot's hand should measure the mass of the object, and determine the grasping force using the mass, finally control the grasping force using the finger sensors and the controller. In this paper, the intelligent robot's hand for a humanoid robot was developed. First, the six-axis force/moment sensor was manufactured. second, three finger force sensors were designed and fabricated, third, the high-speed controller was manufactured using DSP(digital signal processor), finally, the characteristic test for determining a grasping force and for grasping an unknown object safely It is confirmed that the hand could grasp an unknown object safely.

머신비전을 이용한 PCB 스크린인쇄기의 정렬오차측정 및 위치보정 (2) (Measurement and Correction of PCB Alignment Error for Screen Printer Using Machine Vision (2))

  • 신동원
    • 한국정밀공학회지
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    • 제20권6호
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    • pp.96-104
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    • 2003
  • This paper presents the measurement and correction method of PCB alignment errors for PCB screen printer. Electronic equipment is getting smaller and yet must satisfy high performance standard. Therefore, there is a great demand for PCB with high density. However conventional PCB screen printer doesn't have enough accuracy to accommodate the demand for high-resolution circuit pattern and high-density mounting capacity of electronic chips. It is because the alignment errors of PCB occur when it is loaded to the screen printer. Therefore, this study focuses on the development of the system which is able to measure and correct alignment errors with high-accuracy. An automatic optical inspection part measures the PCB alignment errors using machine vision, and the high-accuracy 3-axis stage makes correction for these errors. This system used two CCD cameras to get images of two fiducial marks of PCB. The centers of fiducial marks are obtained by using moment, gradient method. The first method is calculating the centroid by using first moment of blob, and the latter method is calculating the center of the circle whose equation is obtained by curve-fitting the boundaries of fiducial mark. The operating system used to implement the whole set-up is carried in Window 98 (or NT) environment. Finally we implemented this system to PCB screen printer.

Electric Field Dependence Experiments and ab Initio Calculations of Three Cytosine Tautomers in Superfluid Helium Nanodroplets

  • Min, Ah-Reum;Lee, Seung-Jun;Choi, Myong-Yong;Miller, Roger E.
    • Bulletin of the Korean Chemical Society
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    • 제30권12호
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    • pp.3039-3044
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    • 2009
  • We report the first electric field dependence IR spectra of three cytosine tautomers solvated in helium nanodroplets. By using an electric field dependence on the three lowest energy tautomers of cytosine and ab initio calculations, we are able to measure the vibrational transition moment angles (VTMAs), specifically for the $NH_2$ symmetric stretch (SS) mode in this study, with more precision; thus we have reassigned the previous $NH_2$ (SS) VTMA of 74$^{\circ}$ for the C1 tautomer to 85$^{\circ}$, which the latter is in excellent agreement with the ab initio value. Nonplanarity of the three lowest energy tautomers of cytosine has been investigated by measuring the VTMA of each vibrational mode for the tautomers.

Optimum design of steel frame structures considering construction cost and seismic damage

  • Kaveh, A.;Fahimi-Farzam, M.;Kalateh-Ahani, M.
    • Smart Structures and Systems
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    • 제16권1호
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    • pp.1-26
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    • 2015
  • Minimizing construction cost and reducing seismic damage are two conflicting objectives in the design of any new structure. In the present work, we try to develop a framework in order to solve the optimum performance-based design problem considering the construction cost and the seismic damage of steel moment-frame structures. The Park-Ang damage index is selected as the seismic damage measure because it is one of the most realistic measures of structural damage. The non-dominated sorting genetic algorithm (NSGA-II) is employed as the optimization algorithm to search the Pareto optimal solutions. To improve the time efficiency of the proposed framework, three simplifying strategies are adopted: first, simplified nonlinear modeling investigating minimum level of structural modeling sophistication; second, fitness approximation decreasing the number of fitness function evaluations; third, wavelet decomposition of earthquake record decreasing the number of acceleration points involved in time-history loading. The constraints of the optimization problem are considered in accordance with Federal Emergency Management Agency's (FEMA) recommended seismic design specifications. The results from numerical application of the proposed framework demonstrate the efficiency of the framework in solving the present multi-objective optimization problem.

일축 이방성 자성체의 M-H 이력 곡선 측정의 새방법 (A New Method for Measuring M-H Hysteteresis Loop of a Uniaxially Anisotropic Magnetic Material)

  • 허진;신성철
    • 한국자기학회지
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    • 제5권5호
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    • pp.900-904
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    • 1995
  • 돌림힘 자력계를 이용하여 일축 이방성 자성체의 M-H 이력 곡선을 측정하는 새방법을 개발하였다. 본 방법에 의한 M-H 이력 곡선으로부터 포화 및 잔류 자기화량과 보자력을 얻을 수 있었다. 본 방법의 정확도는 자기회사 비균질한 보자력 근처의 인가 자기 마당에서도 영향받지 않았다. $2{\times}10^{-3}$ dyn cm의 측정 감도를 갖는 돌림힘 자력계를 이용한 자기화량 측정에서 $10^{-6}$ emu 이상의 고감도를 얻었다.

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Variation of reliability-based seismic analysis of an electrical cabinet in different NPP location for Korean Peninsula

  • Nahar, Tahmina Tasnim;Rahman, Md Motiur;Kim, Dookie
    • Nuclear Engineering and Technology
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    • 제54권3호
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    • pp.926-939
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    • 2022
  • The area of this study will cover the location-wise seismic response variation of an electrical cabinet in nuclear power point (NPP) based on classical reliability analysis. The location-based seismic ground motion (GM) selection is carried out with the help of probabilistic seismic hazard analysis using PSHRisktool, where the variation of reliability analysis can be understood from the relation between the reliability index and intensity measure. Two different approaches such as the first-order second moment method (FOSM) and Monte Carlo Simulation (MCS) are helped to evaluate and compare the reliability assessment of the cabinet. The cabinet is modeled with material uncertainty utilizing Steel01 as the material model and the fiber section modeling approach is considered to characterize the section's nonlinear reaction behavior. To verify the modal frequency, this study compares the FEM result with recorded data using Least-Squares Complex Exponential (LSCE) method from the impact hammer test. In spite of a few investigations, the main novelty of this study is to introduce the reader to check and compare the seismic reliability assessment variation in different seismic locations and for different earthquake levels. Alongside, the betterment can be found by comparing the result between two considered reliability estimation methods.

Parameter importance ranking for SBLOCA of CPR1000 with moment-independent sensitivity analysis

  • Xiong, Qingwen;Gou, Junli;Shan, Jianqiang
    • Nuclear Engineering and Technology
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    • 제52권12호
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    • pp.2821-2835
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    • 2020
  • The phenomenon identification and ranking table (PIRT) is an important basis in the nuclear power plant (NPP) thermal-hydraulic analysis. This study focuses on the importance ranking of the input parameters when lacking the PIRT, and the target scenario is the small break loss of coolant accident (SBLOCA) in a pressurized water reactor (PWR) CPR1000. A total of 54 input parameters which might have influence on the figure of merit (FOM) were identified, and the sensitivity measure of each input on the FOM was calculated through an optimized moment-independent global sensitivity analysis method. The importance ranking orders of the parameters were transformed into the Savage scores, and the parameters were categorized based on the Savage scores. A parameter importance ranking table for the SBLOCA scenario of the CPR1000 reactor was obtained, and the influences of some important parameters at different break sizes and different accident stages were analyzed.

이미지 신호를 이용한 원자력발전소 강재배관 Tee의 저주기 피로 거동 (Low-cycle Fatigue Behaviors of the Steel Pipe Tee of a Nuclear Power Plant Using Image Signals)

  • 김성완;전법규;정진환;김성도
    • 한국구조물진단유지관리공학회 논문집
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    • 제23권6호
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    • pp.77-83
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    • 2019
  • 원자력발전소에 지진격리장치를 설치하면 지진에 의한 하중을 지진격리장치가 담당하면서 설치 전보다 큰 변위가 발생하게 될 것으로 예상되며, 변위증가에 따라 일부 설비의 지진리스크가 증가될 가능성이 있다. 특히 지진격리된 구조물과 일반 구조물을 연결하는 설비인 배관 시스템의 경우 지진리스크가 크게 증가될 것으로 예상된다. 본 연구에서는 원자력발전소 배관 시스템의 취약부위인 강재 배관 Tee의 한계상태를 누수로 정의하고 면내반복가력시험을 수행하였다. 강재 배관 Tee의 모멘트와 변형각은 기존의 센서를 이용한 계측이 어려우므로 이미지 신호를 이용하여 측정하였다. 본 연구에서는 3인치 강재 배관 Tee의 모멘트와 변형각의 관계를 이용한 누수 선도 및 저주기 피로 곡선들을 제시하였다.

Biomechanical Analysis of Golf Driver Swing Motion According to Gender

  • Bae, Kang Ho;Lee, Joong Sook;Han, Ki Hoon;Shin, Jin Hyung
    • 한국운동역학회지
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    • 제28권1호
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    • pp.1-8
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    • 2018
  • Objective: The purpose of this study is to investigate the differences in biomechanical variables of golf driving motion according to gender. Method: A total of 21 healthy golfers (11 men and 10 women) who have more than 5 years of professional experience and have been registered in the Korea Golf Association was recruited. A 250-Hz 8-camera motion capture system (MX-T20, Vicon, LA, USA) was used to capture the motion trajectories of a total of 42 reflective markers attached to the golfer's body and club. Moreover, two 1,000-Hz AMTI force plates (AMTI OR6-7-400, AMTI, MA, USA) were used to measure the ground reaction force. The mean and standard deviation for each parameter were then calculated for both groups of 21 subjects. SPSS Windows version 23.0 was used for statistical analysis. The independent t-test was used to determine the differences between groups. An alpha level of .05 was utilized in all tests. Results: There were differences in joint angles according to gender during golf driver swing. Men showed a statistically significantly higher peak joint angle and maximum range of angle in sagittal and frontal axis of the pelvis, hip, and knee. Moreover, women's swing of the pelvis and hips was found to have a pattern using the peak joint angle and range of angle in the vertical axis of the pelvis and hip. There were the differences in peak joint moment according to gender during golf driver swing. Men used higher joint moment in the downswing phase than women in the extensor, abductor, and external rotator muscles of the right hip; flexor and adductor muscles of left hip joint; and flexor and extensor muscles of the right knee. Conclusion: This result reveals that male golfers conducted driver swing using stronger force of the lower body and ground reaction force based on strength of hip and thigh than female golfers.