• Title/Summary/Keyword: weighing accuracy

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Overloading Control Effectiveness of Overweight Enforcement System using High-Speed Weigh-In-Motion (고속축중기를 활용한 과적단속시스템의 과적 억제효과 분석)

  • Kwon, Soon-Min;Jung, Young-Yoon;Lee, Kyung-Bae
    • International Journal of Highway Engineering
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    • v.14 no.5
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    • pp.179-188
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    • 2012
  • PURPOSES: The aim of this study is to analyze overloading control effectiveness of enforcing overweighted vehicles using HS-WIM (High-Speed Weigh-in-Motion) at main lane of expressway. METHODS: To analyze the weight distribution statistically, HS-WIM system should has an appropriate weighing accuracy. Thus, the weighing accuracy of the two HS-WIM systems was estimated by applying European specifications and ASTM (American Standards for Testing and Materials) for WIM in this study. Based on the results of accuracy test, overweight enforcement system has been operated at main lanes of two expressway routes in order to provide weight informations of overweighted vehicle in real time for enforcement squad. To evaluate the overloading control effectiveness with enforcement, traffic volume and axle loads of trucks for two months at the right after beginning of the enforcement were compared with data set for same periods before the enforcement. RESULTS: As the results of weighing accuracy test, both WIM systems were accepted to the most precise type that can be useful to applicate not only statistical purpose but enforcing on overweight vehicles directly. After the enforcement, the rate of overweighted trucks that weighed over enforcement limits had been decreased by 27% compared with the rate before the enforcement. Especially, the rate of overweighted trucks that weighed over 48 tons had been decreased by 91%. On the other hand, in counterpoint to decrease of the overweighted vehicle, the rate of trucks that weighed under enforcement limits had been increased by 7%. CONCLUSIONS: From the results, it is quite clear that overloading has been controlled since the beginning of the enforcement.

A Paired Barrel Capable of Automatic Storage and Emptying of Water for a Weighing Raingauge (자동 저수와 배수가 가능한 중량 우량계 용 쌍수조)

  • Lim, Gyu-Ho;Lim, Eun Ok
    • Atmosphere
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    • v.27 no.2
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    • pp.251-258
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    • 2017
  • The standard weighing raingauges have a capacity limit in measuring the amounts of precipitation. Exceptions are those using a siphon to drain the collected water during observations. To reduce the drain time of the siphon type or to overcome the hassles associated with the manual emptying of the bucket for measuring, the most of weighing gauges use a large bucket for storing of rainwater to be measured. To avoid the above-mentioned adverse requirements, we propose a paired barrel for a weighing raingauge. The paired barrel may improve the accuracy of the weighing raingauges by getting rid of their capacity limit and make the gauges smaller in size and lighter in weight than the conventional ones. We showed its proper function and the feasibility of realization by testing a prototype paired barrel.

Improvement of Uncertainty for Gravimetric Flow Calibrator (10톤 용량의 중량식 교정장치에 대한 불확도 개선)

  • Lee, Dong-Keun;Park, Joo-Young;Lee, Haeng-Soo
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.1042-1046
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    • 2008
  • Both the weighing bridge and the diverter system is a important component in achieving a high accuracy liquid flow rate standard using a static gravimetric method. The weighing bridge is a tank which weighing collected flow with a load cells. The diverter is a moving device used to direct flow alternately along its normal course(by pass) or towards the weighing tank. The time needed for collection into the weighing tank is measured using a timer. So it is important to the diversion period is sufficiently fast and triggering point of timer which is determined the filling time. On this studies show that the measurement deviation of load cell and uncertainty of diverter system for changing diversion speed and triggering point was estimated in accordance with Guide to The Expression of Uncertainty in Measurement(ISO).

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A Study of Quantitative Snow Water Equivalent (SWE) Estimation by Comparing the Snow Measurement Data (적설 관측자료 비교를 통한 정량적 SWE 산출에 관한 연구)

  • Ro, Yonghun;Chang, Ki-Ho;Cha, Joo-Wan;Chung, Gunhui;Choi, Jiwon;Ha, Jong-Chul
    • Atmosphere
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    • v.29 no.3
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    • pp.269-282
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    • 2019
  • While it is important to obtain the accurate information on snowfall data due to the increase in damage caused by the heavy snowfall in the winter season, it is not easy to observe the snowfall quantitatively. Recently, snow measurements using a weighing precipitation gauge have been carried out, but there is a problem that high snowfall intensity results in low accuracy. Also, the observed snowfall data are sensitive depending on wind speed, temperature, and humidity. In this study, a new process of quality control for snow water equivalent (SWE) data of the weighing precipitation gauge were proposed to cover the low accuracy of snow data and maximize the data utilization. Snowfall data (SWE) observed by Pluvio, Parsivel, snow-depth meter using laser or ultrasonic, and rainfall gauge in Cloud Physics Observation Site (CPOS) were compared and analyzed. Applying the QC algorithm including the use of number of hydrometeor particles as reference, the increased SWE per the unit time was determined and the data noise was removed and marked by flag. The SWE data converted by the number concentration of hydrometeor particles are tested as a method to restore the QC-removed data, and show good agreement with those of the weighing precipitation gauge, though requiring more case studies. The three events data for heavy snowfall disaster in Pyeongchang area was analyzed. The SWE data with improved quality was showed a good correlation with the eye-measured data ($R^2$ > 0.73).

A Weighing Algorithm for Multihead Weighers

  • Keraita James N.;Kim, Kyo-Hyoung
    • International Journal of Precision Engineering and Manufacturing
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    • v.8 no.1
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    • pp.21-26
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    • 2007
  • In industry, multihead automatic combination weighers are used to provide accurate weights at high speed. To minimize giveaway, greater accuracy is desired, especially for valuable products. This paper describes a combination algorithm based on bit operation. The combination method is simple and saves time, since only the elements to be considered for combination are generated. The total number of combinations from which the desired output weight is chosen can be increased by extending the combination from memory hoppers to include some weighing hoppers. For an eight-channel weigher, three or four combination elements are best. In addition to targeting approximately equal amounts of products in each channel, this study investigated other schemes. Simulation results show that schemes targeting combination elements with an unequal distribution of the output weight are more accurate. The most accurate scheme involves supplying products to all memory and weighing hoppers before commencing the combination operation. However, this scheme takes more time.

Development of Frequency Weighing Sensor and Single Crystal Growth (새로운 무게센서 재발과 단결정성장(1))

  • Jang Y.N.;Sung N.H.;Chae S.C.;Bae I.K.;Kim I.J.
    • Korean Journal of Crystallography
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    • v.8 no.1
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    • pp.38-47
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    • 1997
  • A new weighing sensor for the automatic diameter control system of the crystal growth is developed in this study. This weighing sensor measures the frequency of the vibrating element which is lineally changing with respect to weight. The signal and the power of this system are transmitted without any physical contact, so that this sensor offers high accuracy and resolution. This system consists of a string, a sinusoidal wave generator, an automatic amplification adjusting circuit, signal transformers and a PCB. 4 kinds of programs are developed for checking DAC, weight calibration and controlling growth process. The measurements of the standard deviation and the resolution show $\pm0.10g$(measured at every second) and $5{\times}10^{-5}$, respectively, This weighing sensor is effective under high pres-sure of 200 atm, high temperature and vacuum condition. The weighing system can control the temperature in the accuracy of $\pm0.025^{\circ}C$ with the 'signal divider'. The optical quality single crystals of $(YGd)_3Sc_2Ga_3O_{12},\;Er-Y_3Sc_2Al_3O_{12},\;and\;Bi_{12}GeO_{20}$ have been grown by Czo-chralski method using this auto-diameter control system.

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Development of Rice Yield Prediction System of Head-Feed Type Combine Harvester (자탈형 콤바인의 실시간 벼 수확량 예측 시스템 개발)

  • Sang Hee Lee;So Young Shin;Deok Gyu Choi;Won-Kyung Kim;Seok Pyo Moon;Chang Uk Cheon;Seok Ho Park;Youn Koo Kang;Sung Hyuk Jang
    • Journal of Drive and Control
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    • v.21 no.2
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    • pp.36-43
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    • 2024
  • The yield is basic and necessary information in precision agriculture that reduces input resources and enhances productivity. Yield information is important because it can be used to set up farming plans and evaluate farming results. Yield monitoring systems are commercialized in the United States and Japan but not in Korea. Therefore, such a system must be developed. This study was conducted to develop a yield monitoring system that improved performance by correcting a previously developed flow sensor using a grain tank-weighing system. An impact-plated type flow sensor was installed in a grain tank where grains are placed, and grain tank-weighing sensors were installed under the grain tank to estimate the weight of the grain inside the tank. The grain flow rate and grain weight prediction models showed high correlations, with coefficient of determinations (R2) of 0.9979 and 0.9991, respectively. A main controller of the yield monitoring system that calculated the real-time yield using a sensor output value was also developed and installed in a combine harvester. Field tests of the combine harvester yield monitoring system were conducted in a rice paddy field. The developed yield monitoring system showed high accuracy with an error of 0.13%. Therefore, the newly developed yield monitoring system can be used to predict grain weight with high accuracy.

Validity of Various Anthropometric Equations for the Estimation of Relative Body Fat (신체계측을 이용한 각종 체지방량 추정식의 타당성 평가)

  • 김은경
    • Journal of Nutrition and Health
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    • v.23 no.2
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    • pp.93-107
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    • 1990
  • The purposes of this investigation were to determine the validity of various methods (available anthropometric equations and near-infrared light interactance) for estimating body fat and to develop multiple regression equations for the prediction of body fat. Thirty-eight healthy males(age: 20.87$\pm$7.17 yrs) and 12 females(19.58$\pm$2.19 yrs) underwent hydrostatic weighing to determine body fat. Anthropometric measurements were taken of height, weight, nin skinfolds and thirteen circumferences. The results obtained are summarized as follows: 1) Relative body fat determined by underwater weighing was 12.08$\pm$5.21% for the males and 17.97$\pm$5.75% for the females. 2) Circumference and skin fold that had the highest correlation with the body fat were waist girth in males and females(r=0.60, r=0.96, respectively), and subscapular in males(r=0.68) and triceps in females(r=0.96). 3) Corss-validation of 18 selected equations on males revealed total errors ranging from 3.76% to 5.06%. Among these equations, M3(Pollock et al.) demonstrated the least total error. Total error of estimation by near-infrared(NIR) was less than that of available anthropometric measurement equations. The results of the cross-validation of 12 equations on females revealed that F3(Sloan et al.) was clearly superior in accuracy of prediction. 4) Correlational analyses showed that estimation of body fat by NIR measurement seemed to be more closely associated with body fat determined by underwater weighing in women than men, in older subjects than younger ones, and in fatter subjects than leaner ones.

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Uncertainty Characteristics of Diverter for Flowmeter Calibration System (액체용 유량계 교정시스템의 Diverter 불확도 특성 연구)

  • Lee, Dong-Keun;Park, Jong-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.11 no.3
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    • pp.50-55
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    • 2008
  • The diverter system is a key component in achieving a high accuracy liquid flow rate standard using a static gravimetric system with a flying start and stop method. The diverter is a moving device used to direct flow alternately along its normal course(by pass) or towards the weighing tank. The time needed for collection into the weighing tank is measured using a timer. So it is important to the diversion period is sufficiently fast and triggering point of timer which is determined the filling time. On this studies show that uncertainty of diverter system for changing diversion speed and triggering point was estimated in accordance with Guide to The Expression of Uncertainty in Measurement(ISO).

A Study on Automated Multi-Channel Combination System for the Closest Target Weight (목표중량 근사치 자동 설정을 위한 멀티헤드 조합시스템에 관한 연구)

  • Ahn, Yong-Woo;Ban, Kap-Soo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.6
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    • pp.77-83
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    • 2015
  • This paper is a study of the functions required for the system to quantify the closest target weight by combining several random weights such as chips, snacks, fruits, and vegetables. The multi-head weigher is designed for high-performance applications requiring increased production rates and tight accuracy tolerances. This combination system has 12 heads considered in the form of a rectangular array of $2{\times}6$ or $3{\times}4$. Channel combination can usually occur between 1 and n, and the frequency was the highest with two or three combinations. Experimental result of a combination system for a total target weight was measured at the range from 100g to 500g by increments of 50g, and the average success rate was about 70%. The average elapsed time was about 1.7 seconds, which means it can be used for the packaging of agricultural products with a variety of items.