41results about How to "Avoid Calculation Bias" patented technology

The invention discloses a dynamic compensation method for an ultrasonic flowmeter, which includes the step of measuring time dynamic cycle compensation, and further includes the step of fluid density compensation, the step of temperature compensation for the time difference between the upstream propagation time of ultrasonic waves and the downstream propagation time of ultrasonic waves, The step of dynamically looking up the calibration coefficient through the pre-established calibration coefficient lookup table and the step of flow calculation of multi-level dynamic compensation; thus, the water hammer effect caused by the instantaneous switch of the valve or the residual air bubbles in the pipeline will cause the ultrasonic propagation time measurement If there is a problem with deviation, the dynamic period compensation of the measurement time is carried out; further, the liquid density change caused by temperature is compensated; the temperature compensation is carried out for the time difference reference affected by the temperature change of the components in the circuit box, and the calibration coefficient of the non-fixed value is established. The lookup table performs dynamic lookup during flow calculation.

The invention discloses an onboard energy scheduling method based on energy states and applicable to remote sensing satellites. The method comprises steps that power supply state intervals are divided according to charge conditions of a storage cell set, onboard computer resources are utilized to acquire relevant parameters of an energy system in real time, for an injected satellite work mode, an energy system power supply state is calculated, and scheduling is carried out to determined whether the work mode can be performed. According to the method, power supply capacity and a load electricity load state of the onboard energy system are determined according to the remote measurement parameters in real time, calculation deviation caused by inaccurately-acquired ground budget parameters can be avoided, autonomous onboard energy state calculation under a multi-combination variable work mode is realized, an onboard energy utilization rate is substantially improved, and satellite business capability is improved; according to the autonomous onboard energy state calculation result, onboard energy scheduling can be timely carried out, excessive energy utilization under energy system fault and electricity load increase conditions can be avoided, and safety of the onboard energy system is improved.

The present disclosure provides a method and device for determining the position of a magnetic resonance coil, and a magnetic resonance imaging system. The method includes: acquiring a magnetic resonance signal received by the coil in a pre-scan, and determining projection data of the coil; according to the projection data and the corresponding gradient distortion correction factor, determine the initial center of gravity position of the coil; calculate the initial center of gravity position relative to the The offset of the physical center of gravity of the coil; the initial position of the center of gravity is offset by the offset to obtain the physical center of gravity of the coil. The embodiment of the present disclosure has fast calculation speed and avoids the interference of markers on magnetic resonance signals; and solves the calculation deviation caused by signal distortion and loss when the coil is at the edge of imaging, and improves the accuracy and accuracy of coil positioning.

The invention discloses a method for setting the turbulent kinetic energy inlet boundary of a hypersonic obtuse leading edge flow, which includes the following steps: S1, calculating the basic flow field, and obtaining the steady basic flow field variable; S2, using a numerical simulation system to directly simulate the disturbance wave, Get unsteady flow field variables ϕ ; S3, analyze the flow field to get the disturbance field ϕ' , and obtain the distribution characteristics of the turbulent kinetic energy; S4, set the inlet boundary of the turbulent kinetic energy; S5, calculate the turbulent flow / transition, etc.; the present invention does not need to modify the turbulent kinetic energy equation in the turbulent flow model, and the turbulent kinetic energy can be avoided by setting the inlet boundary condition The calculation deviation of the equation in the downstream of the shock wave is based on the direct numerical simulation results to set a more accurate turbulent kinetic energy inlet boundary condition, which has the advantages of reasonable calculation results, high achievability, and high reliability, and can be extended to three-dimensional flow conditions, etc.

The invention discloses a method for dynamically estimating noise through radar echo and a meteorological radar system and solves a technical problem of non-high meteorological prediction accuracy existing in a meteorological radar system in the prior art which can not acquire dynamically-changed system noise in real time. The method comprises steps that a radar echo signal is converted into an IQ sequence signal, Fourier transform of the IQ sequence signal with the sampling number of N in a kth distance database is carried out, a power spectrum coefficient is calculated to acquire power spectrums sp, the k is a positive integer; the power spectrums sp are ordered in an ascending order, and the ordered power spectrums sp are marked as S; variables mc and b0 are set, during initiation, the mc is made to be equal to the N, and the b0 is made to be 0; when it is determined that the mc is greater than 2, and the b0 is smaller than 1, cycle calculation is carried out according to formulas described in the specification; after each cycle calculation, whether the b1 is not greater than 0 is determined, and the present mc is recorded; if the b1 is not greater than 0, the system noise is estimated by employing the present mc, and thereby the system noise of the kth distance database is acquired according to a formula described in the specification.

The invention discloses a four-electrode electrochemical gas sensor capable of measuring both nitric oxide and hydrogen sulfide in expiratory air. A four-electrode system is formed by two working electrodes, one auxiliary electrode, one reference electrode, one hydrogen sulfide filter and an electrolyte. The four-electrode electrochemical gas sensor is characterized in that the two working electrodes are located on the same horizontal plane and are further spatially relatively independent; the two working electrodes are made from the same electrode material; the hydrogen sulfide filter is located above one of the two working electrodes. The shapes of the working electrodes are semicircular; the electrode material is a gold-doped carbon nanotube, graphite or graphene. The gold-doped workingelectrodes are sensitive to the hydrogen sulfide, and can be used for obtaining a hybrid response signal of the nitric oxide and the hydrogen sulfide; however, a response signal of the nitric oxide can be only obtained on the working electrode provided with the hydrogen sulfide filter; in this way, through calculating a difference value, response signals of the nitric oxide and the hydrogen sulfide can be both obtained on the sensor, and the sensor can be used for realizing simultaneously detecting expiratory nitric oxide and expiratory hydrogen sulfide.