81 results about "Source strength" patented technology

An algorithm diagnoses the noise source strength distribution on an arbitrarily shaped object based on acoustic pressures measured in the far field, known as FANS. FANS enable one to acquire a quick estimate of the acoustic pressure at locations that are off limit to traditional measurement microphones. Generally, in the method of the present invention, the noise source is modeled in terms a plurality of virtual spherical wave sources distributed on an auxiliary surface conformal to a source boundary from the inside, but not on the source boundary itself. Sound is then measured at a plurality of measurement points external to the source boundary. The sound field is reconstructed on the source boundary surface itself.

Method for conducting a seismic survey (23) wherein the acquisition parameters are modified as the survey progresses using information (24) from sensors located to monitor structures and fixtures located in the survey area. The sensor output is compared to acceptable levels, and acquisition parameters such as the seismic source strength are adjusted (26) to prevent exceeding the acceptable levels. An automated arbitration scheme (22) is used to resolve conflicting system goals within survey resource constraints.

The invention provides a method and device for optionally adjusting radon exhalation rate and effective decay constants. During measurement, a solid radon source is placed on the plane of the adjusting device, an opening radon collecting cover of an existing device on the plane of the adjusting device, a plurality of small holes are formed in the plane of the adjusting device, the effective decay constants are adjusted by controlling the small holes to open and close, and the radon exhalation rate is adjusted by using the solid radon sources with different source strengths; the number of the small holes in the plane of the adjusting device is N, the diameter of the hole ranges from 0.1mm to 1mm, and the leakage coefficient of each hole is lambda leak1; if n small holes are sealed, the effective decay constants are calculated through a formula (4): lambda e = lambda + (N-n)* lambda leak1. The adjusting device adopted by the method comprises a plane and an adjusting plate.

Provided is a groundwater pollution source strength evaluation method. The method includes: determining the classified condition of an evaluation site with the combination of the hydrogeological condition around the site according to the construction condition of an industrial site and the implementation condition of seepage prevention measures; dividing the protection grade of vadose zones into three grades of "strong", "medium", and "weak" according to the classified condition of the industrial site, and the thickness and the permeability coefficient of the vadose zones; determining vulnerability indexes and scores of the vadose zones by employing a DRTAS model with the combination of characteristics of the vadose zones, and determining the resistance control classification of the vadose zones according to the protection grade and the vulnerability scores of the vadose zones; determining characteristic indexes of a pollution source and weights thereof by employing overlay and index methods with the combination of characteristics of the pollution source, thereby performing classification of harmfulness of the pollution source; and establishing a groundwater source strength classification evaluation method according to classification matrix coupling, and evaluating the groundwater pollution source strength of the industrial site. According to the method, the groundwater pollution source strength of the industrial site can be accurately evaluated, and scientific basis is provided for the protection and management of groundwater.

The invention discloses a transmission line audible noise multi-channel signal extraction method. The method comprises the steps that (1) framing and windowing are carried out on a multi-channel noisy signal; (2) a wavelet packet decomposing technology is used to carry out signal de-noising; (3) audible noise energy statistical distribution characteristic parameters are calculated for the multi-channel signal, and a power density spectrum is acquired; and (4) inverse transforming is carried out on the power density spectrum to acquire an audible noise signal of a transmission line. According to the invention, an energy statistical distribution characteristic method of wavelet packet decomposing de-noising and singular value decomposing is used; a lot of noise is eliminated; source strength signal is prevented from damage as much as possible; the method has great effects of noise cancellation and source strength extraction; the method is used for extracting the sound source signal of the transmission line, and can be widely used for source strength filtering in a noisy environment.

The invention discloses a method for optimizing parameters of a secondary sound source in active noise reduction of a power transformer. The method comprises the following steps of numbering positions; initializing an amplitude and a phase angle; primarily selecting the amplitude and the phase angle by utilizing a genetic algorithm; substituting the primarily selected amplitude, the phase angle, the number and the positions; performing feasibility judgment; and continuing fine-tuning and optimizing the amplitude and the phase angle of the secondary sound source and the like. The optimization of the parameters of the secondary sound source is a core issue researched by an active noise reduction technology of the power transformer. On the basis of analyzing an active noise reduction physical mechanism, a noise radiation model of the power transformer is established. Considering actual engineering needs, the parameters of the secondary sound source are divided into two categories, and the parameters of the secondary source are optimized from three aspects, namely the number, the position and the source strength. In view of the interaction among the parameters such as the positions and the source strength, fixed parameters and flexible parameters are alternately preferred to form a genetic algorithm-based gradual search approaching strategy, so that a good overall active noise reduction effect can be achieved.

The invention discloses an ultrasonic vibration assisted grinding brittle material grinding temperature prediction method which includes the steps: 1 building a mathematical model of grinding force F in the grinding process; 2 determining heat source strength q; 3 determining temperature rising time t; 4 determining a prediction formula of grinding temperature theta; 5 determining a correction factor K; 6 determining a final prediction formula of planar grinding temperature theta, and predicting the grinding temperature under different parameters. The feeding speed of abrasive particles, the rotating speed of a spindle and the influence of grinding depth on the grinding temperature are taken into consideration, the influence of such factors on the grinding temperature is represented by the correction factor K, and the method is closer to practice.

The invention provides a predicating method and device for an in-vehicle acoustic modal shape. The predicating method for the in-vehicle acoustic modal shape comprises the following steps of: S1, determining in-vehicle acoustic modal shape frequency; S2, acquiring holographic complex sound pressure based on the in-vehicle acoustic modal shape frequency; S3, calculating imaginary source strength according to the holographic complex sound pressure; and S4, obtaining the in-vehicle acoustic pressure distribution through statistics based on a superposition principle of wave to obtain the in-vehicle acoustic modal shape. According to the predicating method for the in-vehicle acoustic modal shape provided by the embodiment of the invention, the cost is reduced; and the predicating efficiency and accuracy are improved.

The invention discloses a traffic air pollutant concentration prediction method based on a meteorological condition. The method comprises the following steps: S1, calculating an integrated emission factor based on equivalent traffic volume; S2, calculating the pollutant emission rate of a link, preprocessing a pollutant diffusion source based on a meteorological condition, and calculating the source strength of the pollutant diffusion source; S3, determining the pollution range and concentration of each pollutant according to the diffusion pattern of each pollutant under the meteorological condition; and S4, calculating the pollutant residual concentration in a current time period and the pollutant concentration in a future time period in an observation area, and predicting the predicted pollutant concentration in the future time period in the observation area. The invention further discloses a traffic air pollutant concentration prediction system based on a meteorological condition. Real-time traffic data and meteorological data are considered in the estimation of traffic air pollutant concentration. The concentration residual of pollutants is also considered. The practicability and accuracy of traffic air pollutant concentration prediction are enhanced.

The invention discloses a method of separating a sound field radiated by a static sound source and a sound field radiated by a rotating sound source. The method is characterized by comprising the following steps: setting a measurement plane in a mixed sound field jointly radiated by a static sound source and a rotating sound source, and using microphones to measure the holographic sound pressure at each measurement point in the measurement plane at receiving time; distributing a static equivalent source and a rotating equivalent source in a sound source plane enveloping the static sound source and the rotating sound source, and building the transmission relationship between mixed equivalent source strength and holographic sound pressure according to the sound radiation laws of the static sound source and the rotating sound source; obtaining the mixed equivalent source strength according to the transmission relationship under known holographic sound pressure, and separating static equivalent source strength and rotating equivalent source strength from the mixed equivalent source strength; and finally, separating a sound field radiated by the static sound source and a sound field radiated by the rotating sound source. The method of the invention can be used to directly implement sound field separation in the time domain, and is applicable to any linear acoustic field, including a steady-state sound field and a non-steady-state sound field.

A pre-computed importance function providing ex ante assessment of optimal placement of a single radioactive source is used for sequential placement of multiple radioactive sources. As each source is placed, the importance function may be modified to reflect the dose implemented by that source and all sources already placed. The greedy algorithm employed by this technique makes possible optimization of additional dimensions of treatment planning including, using directional and isotropic sources, using different source isotopes, using optimum source strengths, using source locations that are not on the regular grid and using a single movable source for variable times at different locations.

The invention aims at providing a sound field separating method. The method comprises the steps of A, measuring a sound pressure value on a measuring surface; B, generating a gray scale according to the sound pressure value generated by a vibrator, calculating the gray value of each point according to the position of actual sound source points, and then calculating a solid ball virtual source strength ball center coordinate and a non-solid ball virtual source strength ball center coordinate by using the gray value of each point as each weight; C, performing zero filling and expansion for the measured sound pressure value of the measuring surface to obtain the sound pressure value on an expanding surface of the measurement surface; D, building a transmission matrix between the expanding surface of the measurement surface, the sound pressure value of the measuring surface and the multi-virtual-ball equivalent source strength sound pressure to obtain a solving equation of the sound pressure on the measuring surface; E, acquiring the sound pressure values of two sound source surfaces according to the sound pressure resolving equation. With the adoption of the sound filed separating method, the defect that the virtual source strength configuration domain and the measurement surface are conformal in the wave superposition method in the prior art can be overcome; meanwhile, the calculation efficiency and precision are increased.

The invention discloses a closed space panel acoustic contribution degree identification method. According to the method, a holographic measurement surface close to an inner surface is set at an internal portion of the closed space, sound pressure sensors are arranged on the measurement surface in a mesh mode, and the distance between adjacent grid points is less than half a wavelength; the orthogonal spherical wave superposition method is utilized to establish the transfer relationship between the sound pressure at the measurement surface and source strength of an orthogonal spherical wave source, and the source strength of the orthogonal spherical wave source is calculated; according to the source strength of the orthogonal spherical wave source, the relationship between the surface normal vibration velocity of the closed space structure and the source strength of the orthogonal spherical wave source is established; the acoustical contribution degree of a closed space panel is calculated through utilizing the sound field equivalence principle. The method is advantaged in that the method is suitable for closed sound fields in any shapes, the quantity of required measurement pointsis small, the method is simple and convenient for enforcement; due to mutual orthogonality of different orders of the orthogonal spherical wave source, the ill conditioning property of a transfer matrix is reduced, and computation accuracy is greatly improved.

The invention discloses a shallow sea sound propagation calculation method applied to three-dimensional sound elasticity analysis of ships, and belongs to the field of the three-dimensional sound elasticity analysis of ships. The method comprises the steps of: establishing a finite element model of a three-dimensional structure; performing dry modal analysis on the finite element model to obtain dry modal parameters of the three-dimensional structure; obtaining a source strength of a wet surface element of the three-dimensional structure according to the dry modal parameters; calculating normal mode parameters for a frequency point according to marine environment parameters; calculating a Green function value of each wet surface element at a field point according to the normal mode parameters, position information of each wet surface element and position information of the field point; calculating a sound pressure level of the three-dimensional structure at the field point on the frequency point according to the Green function value and the source strength of the wet surface element. Thereby, the problem that the calculation amount of the sound radiation and the sound propagation of the three-dimensional structure is large and the efficiency is low is solved and the effect of reducing the amount of calculation, improving the efficiency of calculation, and improving the engineering application value of softwares is achieved.

The invention provides a method for predicting the probability of free-flow road traffic noise based on monte carlo simulation, which is applicable to dynamic simulation calculation for free-flow road traffic noise. The method comprises the following steps: simulating by a free traffic flow monte carlo simulator to obtain a series of data sets formed by several parameters including vehicle number, vehicle type, position and speed on a road at an arbitrary point in time; inputting the data into a vehicle noise emission probability model to obtain a vehicle noise source strength and position data set; and finally calculating a series of noise values at receiving points by combining a noise propagation attenuation calculation model. The method can be used for greatly simplifying the traffic flow simulating process, and has the advantages of simple modeling, small calculated amount and accurate and reliable simulating calculation result.

This invention relates to a system and a method for the perspective detection of a colliery belt, wherein the system comprises a ray source module for producing X ray; a collecting module for collecting the X ray which is received by a detector and penetrates through the belt, and obtaining the information with a definite ray source strength; an environment supervising module for collecting the temperature and the humidity of the ray source and the detector, and supervising the belt speed of going through the detector; and a data transmission module for transmitting the collected transmission data to a remote-control and data processing system through an optical fiber mode. The beneficial effects of this invention are that the system can detect the colliery belt in a non-stopping state, precisely locates the position and abnormal area position of the joint in the belt through integrally scanning and automatically analyzing the belt; improves the detecting efficiency to the abnormal area of the belt; and avoid the harm brought by the traditional X ray detecting apparatus to the detecting workers.

An optical touch control panel comprises a light source unit and a processing unit, wherein the processing unit is used to perform the brightness control method of the optical touch control panel. The brightness control method for the optical touch control panel comprises the following steps of: under a touch control mode, making a light source unit of the optical touch control panel emit light with a first light source strength, responding to a switch condition to switch to a scanning mode, and making the light source unit emit light with a second light source strength.

The invention discloses a tire noise horn amplifying effect predicting method. The tire noise horn amplifying effect predicting method is characterized by including simplifying a tire as a rigid cylinder, disposing the cylinder on a rigid ground, and disposing a point source on a point in a space, with a specific distance away from the cylinder, above the ground as a sound source; arranging an equivalent source in the cylinder, and establishing a transfer relation between the equivalent source strength and sound pressure of a sound field according to a boundary condition that the surface vibration velocity of the rigid cylinder equals to zero; acquiring cylinder surface sound pressure according to sound radiation rules of the point source, and computing the equivalent source strength by combining the cylinder surface sound pressure with the transfer relation between the equivalent source strength and the sound pressure; computing sound pressure at a measurement point of the equivalent source strength; acquiring the sound pressure of the measurement point without the cylinder according to the sound radiation rules of the point source, and combining the sound pressure at the measurement point with the cylinder to obtain a tire noise horn amplifying effect value. The tire noise horn amplifying effect predicting method is capable of predicting tire noise horn amplifying effect efficiently and accurately.