• Title/Summary/Keyword: Flow estimation

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Robust Ultrasound Multigate Blood Volume Flow Estimation

  • Zhang, Yi;Li, Jinkai;Liu, Xin;Liu, Dong Chyuan
    • Journal of Information Processing Systems
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    • v.15 no.4
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    • pp.820-832
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    • 2019
  • Estimation of accurate blood volume flow in ultrasound Doppler blood flow spectrograms is extremely important for clinical diagnostic purposes. Blood volume flow measurements require the assessment of both the velocity distribution and the cross-sectional area of the vessel. Unfortunately, the existing volume flow estimation algorithms by ultrasound lack the velocity space distribution information in cross-sections of a vessel and have the problems of low accuracy and poor stability. In this paper, a new robust ultrasound volume flow estimation method based on multigate (RMG) is proposed and the multigate technology provides detail information on the local velocity distribution. In this method, an accurate double iterative flow velocity estimation algorithm (DIV) is used to estimate the mean velocity and it has been tested on in vivo data from carotid. The results from experiments indicate a mean standard deviation of less than 6% in flow velocities when estimated for a range of SNR levels. The RMG method is validated in a custom-designed experimental setup, Doppler phantom and imitation blood flow control system. In vitro experimental results show that the mean error of the RMG algorithm is 4.81%. Low errors in blood volume flow estimation make the prospect of using the RMG algorithm for real-time blood volume flow estimation possible.

An Experimental Study on the Estimation Flow-rate of Venturi Pump Using LightGBM (LightGBM을 이용한 수력 펌프 유량 추정의 실험적 연구)

  • Jin Beom Jeong;Jihwan Lee;Myeongcheol Kang
    • Journal of Drive and Control
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    • v.20 no.4
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    • pp.123-132
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    • 2023
  • In disaster situations, to facilitate rapid drainage, electric underwater pumps are installed manually. This poses a high risk of electric shock accidents due to a short circuit, and a lot of time is required for hose connection and installation of electrical devices. To solve these problems, a Venturi pump using the venturi effect without external power is used. However, Venturi pumps that operate without external power make it difficult to install flow sensors such as electric devices; consequently, it is difficult to check the real-time flow rate. This paper proposes a flow estimation logic to replace the function of the flow sensor for the venturi pump . To develop the flow estimation logic, the flow characteristics of the venturi pump, according to the operating conditions, were checked. After that, the relationship with the flow rate of the venturi pump was defined using a pressure sensor corresponding to a low-cost sensor. Finally, an analysis of the estimation error was performed using the developed flow estimation logic.

A Study on the Estimation of River Management Flow in Urban Basin (도시유역의 하천유지용수 산정에 관한 연구)

  • 이영화
    • Journal of Environmental Science International
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    • v.5 no.3
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    • pp.377-385
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    • 1996
  • This study aims at the estimation of a river management flow in urban basin analyzing Sinchun basin to be the tributary of Kumho river basin. The river management flow has to satisfy a low flow as natural flow and an environmental preservation flow estimated by a dilution flow to satisfy a target water quality in drought flow. Therefore for the estimation of a river management flow in Sinchun in this study, first Tank model as a basin runoff model estimates a low flow, a drought flow from a flow duration curve in Sinchun, second QUAL2E model as water quality model simulates water quality in Sinchun and estimates environmental preservation flow to satisfy a target water qua%its, BOD 8 mg/l by a dilution flow derived from Kumho river, Nakdong river and around water. And the river management flow is estimated by addition of a use flow and a loss flow to more flow between a low-flow and an environmental preservation flow.

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The Flow rate estimation of CSOs using EC Data (전기전도도를 이용한 CSO의 유량 추정)

  • Choi, Weon-Suk;Song, Chang-Soo
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.5
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    • pp.751-757
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    • 2011
  • The monitoring technique based on electrical conductivity (EC) can provide researchers with some advantages in maintenance management and is cost-effective as compared with existing CSOs monitoring. In this study, the flow rate estimation using EC data was executed in two sites where storm overflow chamber had installed. In the result of A-site, R2 of second order multinomial between dilution ratio of EC and observed flow rate was showed the range of 0.68 ~ 0.77. And $R^{2}$ of B-site was 0.62 ~ 0.81. On the other hand, cumulative frequency of A-site was 43.4 ~ 52.2% in the relative error level of under 20%. And B-site was 10.1 ~ 46.5%. The flow rate estimation formula was improved through consideration of some parameters including antecedent dry days and rainfall duration. And difference between estimated flow rate and observed flow rate in total rainfall event was very small.

The Research of Velocity Estimation Method in Pipe Pumping for Slurry Transportation (슬러리 이송을 위한 관내 유속 추정 방법 연구)

  • Kwon, Seunghee;Jeong, Soonyong;Kim, Yuseung
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.3
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    • pp.21-32
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    • 2014
  • This Research have suggested the new estimation method using parameter estimation algorithm to substitute established velocity and friction factor calculation equation. Established calculation equation has some difficulties for estimation and reflecting exactly flow specification cause parameter uncertainty and material uncertainty governed real phenomenon, so this research has used system modeling method for flow specification estimation and suggested estimation method.

An Iterated Optical Flow Estimation Method for Automatically Tracking and Positioning Homologous Points in Video Image Sequences

  • Tsay, Jaan-Rong;Lee, I-Chien
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.372-374
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    • 2003
  • The optical flow theory can be utilized for automatically tracking and positioning homologous points in digital video (DV) image sequences. In this paper, the Lucas-Kanade optical flow estimation (LKOFE) method and the normalized cross-correlation (NCC) method are compared and analyzed using the DV image sequences acquired by our SONY DCRPC115 DV camera. Thus, an improved optical flow estimation procedure, called 'Iterated Optical Flow Estimation (IOFE)', is presented. Our test results show that the trackable range of 3${\sim}$4 pixels in the LKOFE procedure can be apparently enlarged to 30 pixels in the IOFE.

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Estimation of Inlet Air Mass Flow for Air-Fuel Raito Control of Gaseous-Fuel Engines (기체연료 엔진에서 공연비제어를 위한 흡입공기량 추정)

  • 심한섭;이강윤;선우명호;송창섭
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.5
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    • pp.131-139
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    • 2001
  • Highly accurate control of the air-fuel ratio is important to reduce exhaust gas emissions of the gaseous-fuel engines. In order to achieve this purpose, inlet air mass flow must be measured exactly, and precise engine models are necessary to design engine control systems. In this paper, the effects of water vapor and gaseous fuel that change the air mass flow are studied. The effective air mass ratio is defined as the air mass flow divided by the mixture mass flow, and also it is applied to the estimation of the inlet air mass flow. The presence of the gaseous fuel and the water vapor in the mixture reduces the air partial pressure and the effective air mass ratio of the gaseous-fuel engines. The Experimental results for an LPG engine show that the estimation of the inlet ai mass flow based upon the effective air mass ratio is more accurate than that of the normal air mass flow.

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An algorithm for real time blood flow estimation of LDF (LDF의 실시간 혈류추정을 위한 알고리즘)

  • Kim, Jong-Weon;Ko, Han-Woo
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.78-79
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    • 1998
  • This paper describes a real time algorithm for blood flow estimation of LDF(laser Doppler flowmeter). Many algorithms for blood flow estimation are using power spectral density of Doppler signal by blood flow. In these research, the fast Fourier transformation is used to estimate power spectral density. This is a block processing procedure rather than real time processing. The algorithm in this paper used parametric spectral estimation. This has real time capability by estimation of AR(autoregressive) parameters sample by sample, and has smoothing power spectrum. Also, the frequency resolution is not limited by number of samples used to estimate AR parameter. Another advantage of this algorithm is that AR model enhance SNR.

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A study of motion estimation with optical flow (Optical flow를 이용한 motion estimation에 관한 연구)

  • Byun, Cha-Eung;Kim, Jae-Young;Chung, Chin-Hyun
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1350-1352
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    • 1996
  • The purpose of image sequence coding is to reduce the spatio-temporal redundancies. For the spatial redundancies, we can use the transform coding such as DCT. In this paper, the optical flow method is applied to solve the problem of temporal redundancies. There are several estimation methods like block matching method and pel-recursive method. Block matching method is easy for a hardware implementation because of the computational simplicity. So, it is now used as the estimation method in MPEG-l, MPEG-2, and H.261. We compared the merits and demerits of the optical flow method and the block matching method in this paper.

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Physics-based modelling for a closed form solution for flow angle estimation

  • Lerro, Angelo
    • Advances in aircraft and spacecraft science
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    • v.8 no.4
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    • pp.273-287
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    • 2021
  • Model-based, data-driven and physics-based approaches represent the state-of-the-art techniques to estimate the aircraft flow angles, angle-of-attack and angle-of-sideslip, in avionics. Thanks to sensor fusion techniques, a synthetic sensor is able to provide estimation of flow angles without any dedicated physical sensors. The work deals with a physics-based scheme derived from flight mechanic theory that leads to a nonlinear flow angle model. Even though several solvers can be adopted, nonlinear models can be replaced with less accurate but straightforward ones in practical applications. The present work proposes a linearisation to obtain the flow angles' closed form solution that is verified using a flight simulator. The main objective of the paper, in fact, is to analyse the estimation degradation using the proposed closed form solutions with respect to the nonlinear scheme. Moreover, flight conditions, where the proposed closed form solutions are not applicable, are identified.