• Title/Summary/Keyword: Technical measurements

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Development of engineering software to predict the structural behavior of arch dams

  • Altunisik, Ahmet Can;Kalkan, Ebru;Basaga, Hasan Basri
    • Advances in Computational Design
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    • v.3 no.1
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    • pp.87-112
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    • 2018
  • In this study, it is aimed to present engineering software to estimate the structural response of concrete arch dam. Type-1 concrete arch dam constructed in the laboratory is selected as a reference model. Finite element analyses and experimental measurements are conducted to show the accuracy of initial model. Dynamic analyses are carried out by spectrum analysis under empty reservoir case considering soil-structure interaction and fixed foundation condition. The displacements, principal stresses and strains are presented as an analysis results at all nodal points on downstream and upstream faces of dam body. It is seen from the analyses that there is not any specific ratio between prototype and scaled models for each nodal point with different scale values. So, dynamic analyses results cannot be generalized with a single formula. To eliminate this complexity, the regression analysis, which is a statistical method to obtain the real model results according to the prototype model by using fitting curves, is used. The regression analysis results are validated by numerical solutions using ANSYS software and the error percentages are examined. It is seen that 10% error rates are not exceeded.

The Experimental Study and Comparison on Usage of Vibration Monitoring Sensors for Positioning of Balancing on Rotating Machinery (진동 감시용 위치 결정 센서의 위상오차에 대한 실험적 고찰과 비교 평가)

  • Oh, Seung-Tae;Yoo, Mu-Sang;Bong, Suk-Keun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.25 no.2
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    • pp.101-107
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    • 2015
  • Field balancing is required in any kind of phase information for the determination location balancing mass toward a rotor unbalance mass. Phase or phase angle is a measurement of the relationship of how one vibration signal which relates to another vibration signal and is commonly used to calculate the placement of balance weight. In this paper, A right guideline shows the photo optical speed sensor as the external KeyPhasor is a very useful when diagnosing machinery vibration problems on considering a phase lag comparing to the laser optical speed sensor. Some experimental results generate the interesting phase errors when appling to a wrong conditions. So, Usage of photo optical speed sensor which is used primarily to measure the shaft rotating speed serves as a reference for measuring vibration phase information has effect on the placement of phase angle how it was misunderstood. This paper will help a right method to search for the position of balancing weight and serves as baseline for further measurements using low cost and much easier user convenience. It is concluded that the propose baseline is likely to be applicable to apply to the practical field balancing weight.

Structural identification of concrete arch dams by ambient vibration tests

  • Sevim, Baris;Altunisik, Ahmet Can;Bayraktar, Alemdar
    • Advances in concrete construction
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    • v.1 no.3
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    • pp.227-237
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    • 2013
  • Modal testing, widely accepted and applied method for determining the dynamic characteristics of structures for operational conditions, uses known or unknown vibrations in structures. The method's common applications includes estimation of dynamic characteristics and also damage detection and monitoring of structural performance. In this study, the structural identification of concrete arch dams is determined using ambient vibration tests which is one of the modal testing methods. For the purpose, several ambient vibration tests are conducted to an arch dam. Sensitive accelerometers were placed on the different points of the crest and a gallery of the dam, and signals are collected for the process. Enhanced Frequency Domain Decomposition technique is used for the extraction of natural frequencies, mode shapes and damping ratios. A total of eight natural frequencies are attained by experimentally for each test setup, which ranges between 0-12 Hz. The results obtained from each ambient vibration tests are presented and compared with each other in detail. There is a good agreement between the results for all measurements. However, the theoretical fundamental frequency of Berke Arch Dam is a little different from the experimental.

Validation of Serpent-SUBCHANFLOW-TRANSURANUS pin-by-pin burnup calculations using experimental data from the Temelín II VVER-1000 reactor

  • Garcia, Manuel;Vocka, Radim;Tuominen, Riku;Gommlich, Andre;Leppanen, Jaakko;Valtavirta, Ville;Imke, Uwe;Ferraro, Diego;Uffelen, Paul Van;Milisdorfer, Lukas;Sanchez-Espinoza, Victor
    • Nuclear Engineering and Technology
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    • v.53 no.10
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    • pp.3133-3150
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    • 2021
  • This work deals with the validation of a high-fidelity multiphysics system coupling the Serpent 2 Monte Carlo neutron transport code with SUBCHANFLOW, a subchannel thermalhydraulics code, and TRANSURANUS, a fuel-performance analysis code. The results for a full-core pin-by-pin burnup calculation for the ninth operating cycle of the Temelín II VVER-1000 plant, which starts from a fresh core, are presented and assessed using experimental data. A good agreement is found comparing the critical boron concentration and a set of pin-level neutron flux profiles against measurements. In addition, the calculated axial and radial power distributions match closely the values reported by the core monitoring system. To demonstrate the modeling capabilities of the three-code coupling, pin-level neutronic, thermalhydraulic and thermomechanic results are shown as well. These studies are encompassed in the final phase of the EU Horizon 2020 McSAFE project, during which the Serpent-SUBCHANFLOW-TRANSURANUS system was developed.

A Study on Development of Chinese Men's Apparel Sizing System (중국(中國) 성인남성용(成人男性用) 의류치수규격(衣類値數規格) 설정연구(設定硏究) I)

  • Sohn, Hee-Soon;Lim, Soon;Kim, Jee-Yeon
    • Journal of Fashion Business
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    • v.8 no.1
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    • pp.1-15
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    • 2004
  • The purpose of this study is to provide for some basic data useful to production of the apparels fit and measured well for the Chinese men. For this purpose, Chinese men's apparel measurements and specifications were determined per area group(Beijing/ Shanghai) according to the Men's Wear Specifications (GB/T 1335.1-1997), National Standards of People's Republic of China. The collected data were statistically processed using SAS 6.12 for technical statistical analysis, correlation analysis, factor analysis, group-wise analysis and ANOVA. The results of this study can be summarized as follows; 1. As a result of dividing the Chinese men into Beijing and Shanghai men and thereby, setting height and upper chest circumference for upper garments and height and waist for lower garments. 2. Analyzing the correlations according to the three-fold classifications of height/upper chest circumference/waist for garment specifications, 17 specifications based on heights and upper chest circumferences for Beijing men's upper garments could be designed within the deviation level of 2%, while 15 specifications based on waist measurements could be designed (between $70{\sim}98cm$) for their lower garments within the deviation level of 4%. Thus, a total of 60 combinations of the specifications could be obtained. 3. 16 specifications based on heights and upper chest circumferences for Shanghai men's upper garments could be designed within the deviation level of 2%, while 16 specifications based on waist measurements could be designed (between $68{\sim}98cm$) for their lower garments within the deviation level of 3%. Thus, a total of 56 combinations of the specifications could be obtained. For other reference measurements, grading measures were set for each type and body part, while the average measures of major body parts were calculated.

도시철도용 전력설비 절연 이상측정 장치를 이용한 전자파 특성 분석

  • Gang, Hyeon-Il;Im, Hyeong-Gil;Park, Hyeon-Su;Yu, Gi-Seon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.236-236
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    • 2009
  • This paper demonstrates the application of the preventive maintenance, process to analyse and develop preventive maintenance tasks for rectifier and electric transformer in the SeoulMetro company. Attention is given to the frequency designation, technical details regarding the radiometer, previous electromagnetic noise measurements, and applications of the noise data. This study confirms the feasibility and effectiveness of preventive maintenance applications in the electric trains.

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Microwave-Induced Negative-Differential Resistance Observed in Josephson Junction (마이크로파가 조셉슨 접합에서 유발하는 부의 미분저항)

  • Kim, Kyu-Tae;Koutovoi, Viatcheslav D.;Hong, Hyun-Kwon
    • 한국초전도학회:학술대회논문집
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    • v.9
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    • pp.237-237
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    • 1999
  • We have observed that a stable and reproducible Negative Differential Resistance(NDR) is induced by external microwave at low power in Nb/AlO$_x$/Al/Alo$_x$/Nb junctions. To study the erratic and pozzling NDR observations we have simulated Stewart-McCumber model in the region. Experimental results and simulation results will be presented with a discussion to draw a dynamic interpreration of the NDR.

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Flexible 3-dimension measuring system using robot hand

  • Ishimatsu, T.;Yasuda, K.;Kumon, K.;Matsui, R.
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.700-704
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    • 1989
  • A robotic system with a 3-dimensional profile measuring sensor is developed in order to measure the complicated shape of the target body. Due to this 3-dimensional profile measuring sensor, a computer is able to adjust the posture of the robot hand so that complicated global profile of the target body can be recognized after several measurements from the variant directions. In order to enable fast data processing, a digital signal processor and a look-up table is introduced.

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Study on the Strength Retention of Technical Cord Yarn

  • Cho Dae-Hwan;Jeong Young-Jin
    • Fibers and Polymers
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    • v.7 no.3
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    • pp.305-309
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    • 2006
  • This research studies the factors which influence the tensile strength of tire cords. Five yam samples are made by changing the spinning conditions and viscosity to get various physical properties. Different twisting methods are introduced and the yams are twisted under different processing conditions for each twisting process. With the experimental results, various analyses are performed to find the important factors in retaining strength after the twisting process. SEM and optical microscopic photographs are taken along with some measurements to assist the analysis.

Technical review of discrimination method between strain and temperature on the FBG sensor (FBG 센서의 온도와 변형률 동시 측정기법 기술 분석)

  • Yoon, Hyuk-Jin
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.574-583
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    • 2008
  • FBG(Fiber Bragg grating)s have shown a great potential for sensing applications, and are easily embedded in materials with a negligible impact on the mechanical properties of the host. However, the use of FBG sensors is limited by their simultaneous dependence on strain and temperature, thus only one parameter can be determined from a single grating. This paper reviews various methods to discriminate between strain and temperature effects. To overcome this cross sensitivity using only embedded optical fibers, a number of techniques have been proposed, most of them relying on the deconvolution of two simultaneous measurements.

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