• Title/Summary/Keyword: Direct measurement

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Precise Forces Prediction by Indirect Force Measurement and Pseudo-inverse Technique (Indirect force 측정 방법과 Pseudo-역행렬을 이용한 정밀한 Force 예측)

  • 심재술;안병하;하종훈;정현출
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.564-567
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    • 1997
  • In the design of structure the forces acting on the structure are important parameter for noise and vibration control. However, in the complex structure, the forces at the injection point on the structure cannot be measured directly. Thus it is necessary to find out indirect force evaluation method. In this paper forces have been measured with in-situ vibration responses and system information. Three existing techniques of indirect force measurement, viz. direct inverse, principal component analysis and regularization have been compared. It has been shown that multi-vibration responses are essential for the precise estimation of the forces. To satisfy those conditions, Rotary compressor is adopted as test sample, because it is very difficult to measure the injection forces from internal excitation to shell. It has also been obtained that relatively higher force is transmitted though three welding paths to the compressor shell. It shows a good agreement between direct and indirect force evaluation with curvature shell and plate and is investigated the possibility of force evaluation of rotary compressor as a complex structure.

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A Study on the Transient Measurement of the Effective Thermal Diffusivity of Insulation Materials by NPE Method (NPE법을 이용한 절연재료의 유효열확산계수의 과도측정에 관한 연구)

  • Lim, Dong Joo;Bae, Sin Chul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.2 no.3
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    • pp.243-255
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    • 1990
  • The objective of this study is to present an efficient measurement method of the effective thermal diffusivity for the fibrous insulation material. The non-linear parameter estimation (NPE) method is adapted for this analysis because of its accuracy and its results are compared with those by other direct methods such as CTP, CHP and STD method. A experimental system is constructed with bell-jar vaccum chamber, diffusion pump, tube type furnace, control unit and data acquisition system included with A/D converter and IBM XT/AT personal computer. The typical results obtained from this study are as follows; 1) NPE method can be recommended as an useful and accurate method to measure the effective thermal diffusivity of insuation material because it is shown that the measurement error compared with those by other direct methods is reduced for standard material, NBS-1450b. 2) NPE method can minimize the effects of ill-measured temperature due to external disturbance, because the final value is found by point to point estimating. 3) NPE method dose not depend on the kinds of heat flux, since the surfac temperature are used to estimate the thermal diffusivity. 4) With NPE method, compared with the steady state method, a measuring time and a sample size could be reduced.

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A Study on CO2 Emission Factor for Earth-Work Equipment Using C-FVM (C-FVM을 이용한 토공장비의 CO2 배출계수에 관한 연구)

  • Kim, Byung-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.3
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    • pp.999-1006
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    • 2014
  • $CO_2$ emission factor for earthwork equipment was made based on fuel consumption quantity using IPCC carbon emission factor. This is presented through the carbon emission estimating guideline each facilities by the Ministry of Land, Infrastructure and Transportation in 2011. However, this method has the defect which don't apply the various condition of site. Therefor it needs the new emission factor supplemented these defects. This study will tries to estimate $CO_2$ emission with the direct measurement method using concentration flow velocity measurement (C-FVM) for earth work equipment and present the new $CO_2$ emission factor for earth work equipment after compare with emission factor of the Ministry of Land, Infrastructure and Transportation.

A Study on the Pattern Development of Baseball Cap (베이스볼 캡(Baseball cap)의 패턴 개발에 관한 연구)

  • Kim, Na-Young;Jang, Jeong-Ah
    • Fashion & Textile Research Journal
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    • v.12 no.5
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    • pp.650-656
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    • 2010
  • To present a 6-piece baseball cap pattern with good wearing sensation and with good reflection of head shape, this study conducted direct measurement using martin's anthropometer and indirect measurement using surgical tape among women of 20 to 24 years old. For a crown, correlation analysis was carried out between direct measurements and surface shell measurements of each section on the head to set main items for prototype design, along with regression analysis to complete design formula; for a cap pattern, draping design was used on the finished crown to compete cap pattern design formula. The results showed that main measurement items to design a baseball cap included head circumstance and bitragion arc for a crown and the cephalic index for a cap. For the crown pattern reflecting the shape of the head, 6 pieces were designed with different sizes and types of front (F), side (S), and back (B) patterns; hemline was also designed diagonally and completed by reflecting the curve of the head.

Cluster Analysis for Foot Type(I) - The subject of the college women between the age of 19~23 years - (발의 형태 분석을 위한 군집분석(I) - 19~23세 여자 대학생을 중심으로 -)

  • 문명옥
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.2
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    • pp.211-220
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    • 1994
  • The purpose of this study was to analyze the foot type by cluster analysis for footwear. The sample size for the study was 200 college womens between age 19 and 23 in Pusan urban area. There were measured 17 items of the foot for factor analysis and cluster analysis. The result was as follows : 1. 1'here were 9 items selected by factor analysis. 2.'rho cluster analysis of the foot must be analyzed by direct and indirect measurement indivisually. 3. The cluster analysis of the direct measurement ; Cluster 1 : 1'he foot length is all much the same to mean value of this age group and the items of width and circumference are relatively small to other clusters. Cluster 2 ; The foot length is relatively small to other clusters and the items of width and circumference are all much the same to mean value of this age group. Cluster 3 ; The foot sine Is relatively large to other clusters. 4. The cluster analysis of indirect measurement ; Cluster 1 ; The (cot print angle is high find Metatarso-Phalanx angle is transformed Cluster 2 ; The foot print angle is low and Melatarso-Phalanx angle is normal. Cluster 3 : Tho foot print angle Is middle and Metatarso-Phalanx angle is all the mush same to mean value of this age group. Cluster 4 . The foot print angle Is the most value and Metatarso-Phalanx angle is normal.

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A Study on The Causal Relationships Between The International Model of ICT Using The National Quality Award Model (국가품질상 모델을 적용한 ICT산업의 인과 관계 분석 연구)

  • Shin, Dongkeun;Hwang, Changyu
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.14 no.1
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    • pp.87-101
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    • 2018
  • The purpose of this study is to develop the measuring instruments for evaluation criteria for Malcolm Baldrige National Quality Award(MBNQA), suitable for ICT Industries, and to analyze the cause-effect relationship between those criteria through aforementioned instruments. MBNQA is formed with seven categories: Leadership, Strategic planning, Focus on patients, other customers and markets, Measurement, analysis and knowledge management, Human resource focus, Process management and Results. As excluding the Human Resource Focus category, this study empirically examined the cause-effect relationship among six categories. In order to empirically examine the research model, this study calculated Cronbach's alpha and reliability index, thus examined the reliability and executed Exploratory Factor Analysis. Furthermore, Average Variance Extracted(AVE) is used to verify the discriminant validity. Lastly, the hypothesis testing was made complete through significance test on the paths between variables. The result of this study shows that both leadership and social responsibility have direct cause-effect relationship with Measurement, analysis and knowledge management, Human resource focus, Process management and also that this relationship has direct impact on Human resource focus, Measurement, analysis and knowledge management as well, consequently exerting influence on the result through Process management, Finance and Market data.

Doppler LIDAR Measurement of Wind in the Stratosphere

  • Dong, Jihui;Cha, Hyun-Ki;Kim, Duk-Hyeon;Baik, Sung-Hoon;Wang, Guocheng;Tang, Lei;Shu, Zhifeng;Xu, Wenjing;Hu, Dongdong;Sun, Dongsong
    • Journal of the Optical Society of Korea
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    • v.14 no.3
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    • pp.199-203
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    • 2010
  • A mobile direct detection Doppler LIDAR based on molecular backscattering for measurement of wind in the stratosphere has been developed in Hefei, China. First, the principle of wind measurement with direct detection Doppler LIDAR is presented. Then the configuration of the LIDAR system is described. Finally, the primary experimental results are provided and analyzed. The results indicate that the detection range of the designed Doppler LIDAR reached 50 km altitude, and there is good consistency between the molecular Doppler wind LIDAR(DWL) and the wind profile radar(WPR) in the low troposphere.

Identification of structural systems and excitations using vision-based displacement measurements and substructure approach

  • Lei, Ying;Qi, Chengkai
    • Smart Structures and Systems
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    • v.30 no.3
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    • pp.273-286
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    • 2022
  • In recent years, vision-based monitoring has received great attention. However, structural identification using vision-based displacement measurements is far less established. Especially, simultaneous identification of structural systems and unknown excitation using vision-based displacement measurements is still a challenging task since the unknown excitations do not appear directly in the observation equations. Moreover, measurement accuracy deteriorates over a wider field of view by vision-based monitoring, so, only a portion of the structure is measured instead of targeting a whole structure when using monocular vision. In this paper, the identification of structural system and excitations using vision-based displacement measurements is investigated. It is based on substructure identification approach to treat of problem of limited field of view of vision-based monitoring. For the identification of a target substructure, substructure interaction forces are treated as unknown inputs. A smoothing extended Kalman filter with unknown inputs without direct feedthrough is proposed for the simultaneous identification of substructure and unknown inputs using vision-based displacement measurements. The smoothing makes the identification robust to measurement noises. The proposed algorithm is first validated by the identification of a three-span continuous beam bridge under an impact load. Then, it is investigated by the more difficult identification of a frame and unknown wind excitation. Both examples validate the good performances of the proposed method.