99 results about "Noise index" patented technology

A scout image of a subject is displayed. An operator designates at least one range in a body-axis direction, of the scout image. Further, the operator graphically inputs or key-inputs and sets imaging condition parameters such as a helical pitch, a noise index and the like for a shuttle mode helical scan with being made independent every ranges. Thus, conditions such as helical pitch and noise index for the shuttle mode helical scan can efficiently and intelligibly be set independently for each region or organ, and hence the control/optimization of imaging conditions is enabled.

A system and method of medical imaging is designed to reduce a patient's X-ray exposure during scanning. The system automatically generates a default noise index from a received set of scan parameter values that specifies a desired tube current of an X-ray source to use during the scanning of a patient. The default noise index can then be overridden to select a preferred noise index based upon a desired diagnostic quality for a particular volume of interest (VOI) and a diagnostic objective.

The invention provides intelligent environmental noise and vibration monitoring device and method. The device and method are characterized in that equivalent traffic flow and vehicle speed and other parameters of the road traffic in the monitoring period can be converted by a recommending device or system while the environmental noise and the road traffic noise indexes can be measured through the general sound level meter or a statistic analyzing device and a plurality of index values of the noise are measured; therefore, the field investigation of the road traffic noise can be performed conveniently; meanwhile, an FPGA (Field Programmable Gate Array) embedded system can be used for continuously expanding other synchronous detection functions of the environmental noise, so as to realize an intelligent system.

A method for assessing noise generated during combustion in an internal combustion engine, such method comprising determining a noise index by processing a signal generated in a cylinder of such engine in accordance with a shift invariant wavelet transform.

The invention relates to a construction method of floating floor. The method is characterized by giving detailed description of room floating floor construction and quality control in rooms of high-level acoustic technology requirements, and controlling room acoustic technology requirements of rooms such as a studio, a recording room, a control room, a dubbing studio and a standard viewing room; for the floating floor, elastic damping cushion blocks are arranged on a structural layer, glass fiber is filled in the cushion blocks to absorb shock waves or sound waves, lumber-core boards is arranged on the elastic damping cushion blocks, a waterproof layer is made, steel bars are banded and concrete is poured and firmed by ramming to form a topping, and space between the two layers of structures is made overhead by the elastic damping cushion blocks, thus noise index requirements of transmitting vibration and sound outside the room to the acoustic technology room by the structures are achieved.

A nonlinear multi-target range robust optimization based automobile noise reduction method comprises the steps of 1, conducting mathematical modeling for performance indexes, determining design variables of an automobile structure, determining a noise index at an observation point according to finite element calculation results, and establishing a multi-target optimization model; 2, describing all uncertain parameters of a system with ranges; 3, on the basis of range order relations and sensitivity analyses, conducting robustness processing of objective functions on the noise index; 4, on the basis of range possibility degrees, conducting feasible robustness conversion on constraint conditions; 5, converting a two-layer nesting optimization problem into a conventional single-layer optimization problem with an improved Taylor expansion method; and 6, solving the converted certainty multi-target optimization problem, and determining design values of all components of an automobile to achieve the optimal noise reduction effect. By the aid of the method, the automobile noise reduction problem containing range parameters can be solved systematically, the insensitivity to parameter fluctuations is improved, and the usage safety of the automobile structure and the stability of the noise reduction performance are improved.

Method of operating an X-ray CT apparatus and the corresponding apparatus and system thereof. A method includes analyzing scout scan data to obtain a position with a minimum noise index and a position with a maximum noise index, calculating noise indexes at the two positions in a range of a maximum and a minimum tube current that can be provided by the system by means of a tube current control model so as to obtain two ranges of noise index, and determining whether there is an intersection between the two ranges of noise index. If such an intersection exists, a combination of the range of tube current value and the range of noise index that meets the requirement is selected within the intersection to control the system to proceed with a subsequent scan. If no such intersection exists, the system ends the present scan.

The invention discloses an intelligent health service system based on health big data. The system comprises an acquisition module and a system data center. The acquisition module acquires human body physique data and is connected with the system data center through the Internet for data return. The human body physique data comprises ages, blood types, health check reports, medical reports, medication records, familial inheritance, work pressure, dietary habits, sleep habits, sleep quality, motion mass, mood swing, air quality, weather conditions, temperature and humidity and noise indexes. The system data center provides customized intelligent health services including health tracking, health monitoring, health records, health consultants, health reminding, health evaluation, health common sense and health consultation for users according to the big data analysis technology and in combination with health management specialized knowledge and medical service resources. By means of the technical scheme, the health status and living quality of residents are improved, and the medical healthcare cost is reduced.

The invention provides an erbium doped fiber amplifier real time detection system. A main optical path of an erbium doped fiber amplifier is connected with a bandpass filtering module. A data analysis module, a filtering module and a narrowband power detection module are set. After signals of an input end or an output end pass through the bandpass filtering module and the filtering module, short wavelengths and long wavelengths enter the data analysis module through the narrowband power detection module. The wideband characteristics of spontaneous emission noise of the fiber amplifier are utilized; real-time online detection of system indexes (input/output OSNR, signal gain, noise index and the like) of nodes of an optical transmission system including the fiber amplifier can be achieved; the structure is simple and the response is in time; and significance is provided for system performance monitoring, network management, system installation and maintenance, and the like.

The invention provides a signal transceiver. The signal transceiver includes a first power amplifier coupled to a chip output port of a chip; an impedance transforming circuit; a switching circuit arranged to selectively couple the chip output port to a first port of the impedance transforming circuit; and a receiving amplifier coupled to a second port of the impedance transforming circuit. The signal transceiver can improve linearity of a power amplifier in the chip and reduce the noise index of a low noise amplifier in the chip.

The invention discloses a self-adaptive method and device for eliminating interference of multiple antennae through diversity and mergence. The method comprises the following steps of: measuring noise power of each receiving antenna; judging whether the ratio of the sum of diagonal elements of an NI (Noise Index) matrix of a data carrier to be detected to an average value of the noise power of all receiving antennae is larger than a preset threshold value; if so, carrying out interference suppression and mergence detection on the data carrier to be detected; and if not, carrying out noninterference suppression and mergence detection on the data carrier to be detected. Starting from an NI estimation matrix as the most fundamental factor influencing an IRC (Interference Rejection Combining) merging algorithm, whether the currently obtained NI matrix contains more interference components is judged through the specific numerical value characteristic of the NI matrix, and then, an IRC algorithm or MRC (Mixed Radix Conversion) algorithm is selected, so that the system obtains the optimal performance.

The embodiment of the invention discloses a parameter simulation processing method and device. The method comprises the following steps: according to input optical power and output optical power of an optical amplifier, acquiring a gain reference spectrum and a noise index reference spectrum of the optical amplifier under the condition of the full wave input; obtaining a gain output spectrum and a noise index output spectrum of the optical amplifier according to a preset physical parameter value of the optical amplifier, fitting the physical parameter of the optical amplifier by comparing the gain reference spectrum with the gain output spectrum of the optical amplifier, comparing the noise index reference spectrum of with the noise index output spectrum of the optical amplifier, and iteratively modifying the preset physical parameter value of the optical amplifier; and simulating the performance parameter of the optical amplifier according to physical parameter, service wavelength, input optical power and input optical signal to noise ratio of the optical amplifier. The device comprises an acquiring module, a fitting module and a simulating module. According to the parameter simulation processing method and device provided by the embodiment of the invention, the rapidness of an analytical module and the accuracy of a numerical model are fused, all physical parameters required by the calculation are acquired accurately, and the accuracy of the simulation result is increased.

A low-noise switched-capacitor circuit with a built-in amplifier relates to a switched-capacitor circuit. The low-noise switched-capacitor circuit comprises a switched-capacitor circuit and an active amplifier, wherein the switched-capacitor circuit includes a switch, a capacitor and an amplifier; the input terminal of the active amplifier is connected with the switch; the output terminal of the active amplifier is connected with the capacitor; and the capacitor is connected with the negative input terminal of an operational amplifier. The low-noise switched-capacitor circuit can be used for a switched-capacitor amplifier, a switched-capacitor integrator and other switched-capacitor circuits of other types to meet the requirement for low noise of the system and simultaneously reduce the occupied chip areas and the power consumptions of the capacitor and the operational amplifier. The low-noise switched-capacitor circuit can maximally reduce the desired chip area and the power consumption for the switched-capacitor circuit during low-noise operation, so that the noise index of the switched-capacitor circuit is not restricted by sampling noise, i.e. KT/C noise, of the capacitor.

The invention discloses an intelligent rescue system for a child in a closed automobile. The intelligent rescue system for the child in the closed automobile comprises a noise sensor, a microcontroller, a recording unit and an alarm unit, wherein the noise sensor is arranged in the automobile and is used for collecting a noise index in the automobile and transferring information to the microcontroller; the recording unit is arranged in the automobile and is used for recording noise data in the automobile under the control of the microcontroller; the alarm unit is arranged outside the automobile; the microcontroller is provided with an input module which is used for inputting a critical value of the noise index and the starting time of the recording unit; the recording unit is connected with the alarm unit and is used for transferring the noise data in the automobile to the alarm unit for playing; the microcontroller is connected with an air supply device, an automobile lamp control circuit and a loudspeaker control circuit in the automobile. The intelligent rescue system is designed for the child who is locked in the closed automobile, a sound-triggered intelligent rescue system is adopted, the life safety of the child is ensured, the child can call for rescue, the safety coefficient is improved, and the rate of trigger based on external factors is reduced.

The invention discloses a vehicle noise index decomposition method, device and system for a rail transit vehicle and a computer readable storage medium. The vehicle noise index decomposition method comprises the steps that noise indexes of various noise components of the vehicle in an initial state are acquired; according to the noise indexes of the noise components, interior noise and exterior noise of the vehicle are calculated, and predicted values of the vehicle noise indexes are obtained; whether the predicted values of the vehicle noise indexes meet the corresponding preset conditions ornot is judged, and if yes, a next step is entered and the current noise indexes of the noise components in the vehicle are output; and if no, the noise indexes of the noise components corresponding to the vehicle noise indexes which do not meet the corresponding preset conditions are modified to update the noise components of the vehicle, and the step of acquiring the noise indexes of the noise components of the vehicle in the initial state is returned and performed until the predicted values of the vehicle noise indexes meet the corresponding preset conditions. The vehicle noise index decomposition method, device and system for the rail transit vehicle and the computer readable storage medium are conducive to improving vehicle performance and reducing the operation difficulty and costs of the vehicle in a later stage.

The invention discloses a low noise amplifier which comprises four p-channel metal oxide semiconductor (PMOS) tubes, five inductors, four resistors, two capacitors. The four PMOS tubes comprise a PMOS tube B1, a PMOS tube B2, a PMOS tube B3 and a PMOS tube B4. The five inductors comprise an inductor L1, an inductor L2, an inductor L3, an inductor L4 and an inductor L5. The four resistors comprise a resistor R1, a resistor R2, a resistor R3 and a resistor R4. The two capacitors comprise a capacitor C1 and a capacitor C2. An input end is connected with one end of the L1 and one end of the R2, the other end of the L1 is connected with a grid electrode of the B3, and the other end of the R2 is connected with a grid electrode of the B1. The grid electrode and a drain electrode of the B1 are connected in a short circuit mode, and a source electrode of the B1 is in ground connection. Supply voltage is connected with one end of the R1, one end of L2, one end of the L3 and a grid electrode of the B2, the other end of the R1 is connected with the drain electrode of the B1, the other end of the L2 is connected with a drain electrode of the B2 and a grid electrode of the B4, and the other end of the L3 is connected with a drain electrode of the B4. One end of the R3 is connected with the drain electrode of the B2, the other end of the R3 is connected with a positive electrode of the C1, a negative electrode of the C1 is connected with one end of the L4, and the other end of the L4 is connected with an output end. A positive electrode of the C2 is connected with the drain electrode of the B4, and a negative electrode of the C2 is in ground connection. A source electrode of the B2 is connected with a drain electrode of the B3, a source electrode of the B3 is in ground connection through the L5, and a source electrode of the B4 is in ground connection through the R4. The low noise amplifier can achieve gains more than 30db, and can obtain a noise index below 1.5db at the same time.

The present invention aims at providing one simple and cheap test device and method for measuring the gain flatness and noise index of light amplifier in the evaluation and measurement of light devices for wavelength division multiplexing system. The noise source part is connected to the wavelength dividing part, and the wavelength dividing channels of the wavelength dividing part are connected to the channels in wavelength synthesizing part. The wavelength synthesizing part is connected to the signal light amplifier part, which consists of fiber amplifier and adjustable attenuator. The wavelength dividing part consists of channel interleaver and wavelength dividing device. The said test device is connected to the light amplifier to be tested and spectral analyzer successively for measuring gain flatness and noise index of light amplifier of the light amplifier.

The invention discloses a front-end circuit for an analogue-to-digital converter with a pipeline structure and a time sequence control method for the front-end circuit, and aims to eliminate a sampling and holding amplifier, improve power consumption and noise indexes and reduce conversion delay. The front-end circuit is used for realizing the analogue-to-digital conversion of M1+M2 bits, and acquiring a second analogue residual error signal, wherein the second analogue residual error signal is used for the sampling of the next conversion stage of the front-end circuit in the analogue-to-digital converter with the pipeline structure. The front-end circuit comprises a first conversion stage and a second conversion stage, wherein the first conversion stage is used for directly sampling an input signal to finish the analogue-to-digital conversion of M1 bits, and acquiring a first analogue residual error signal; and the second conversion stage is used for receiving and sampling the first analogue residual error signal to finish the analogue-to-digital conversion of M2 bits, and acquiring the second analogue residual error signal.

The invention provides a ship underwater radiation noise assessment method. The method comprises the following steps: 1, inputting ship length, equipment type selection and total number of ship conceptual schemes, and equipment to ship bow distance; 2, identifying the exciting force of the mass center position of the equipment; 3, calculating a far-field underwater radiation noise sound source level and a frequency band sound source level of single-machine equipment of the ship; 4, calculating the total sound level of each point from the bow to the stern at the transverse a-meter position of the ship, drawing a characteristic curve of longitudinal distribution of sound pressure along the ship body as a passing characteristic curve of the ship, and determining the equivalent sound center ofthe ship; 5, estimating an underwater radiation noise source level, a frequency band sound source level and a sound pressure spectrum source level of the ship; and 6, comparing the parameters obtained in the step 5 with a design demand limit value to obtain a ship underwater radiation noise index argumentation and evaluation result. The far-field sound pressure value of the ship under the navigation working condition can be estimated according to the ship concept scheme at the demonstration stage, and demonstration evaluation is carried out on the far-field sound pressure value according to the demand limit value.

A noise suppression estimation device calculates a noise index value which varies according to kurtosis of a frequence distribution of magnitude of a sound signal before or after suppression of the noise component, the noise index value indicating a degree of occurrence of musical noise after suppression of the noise component in a frequency domain. For example, the noise suppression estimation device calculates first kurtosis of a frequence distribution of magnitude of the sound signal before suppression of the noise component, calculates second kurtosis of a frequence distribution of magnitude of the sound signal after suppression of the noise component, and calculates the noise index value from the first kurtosis and the second kurtosis.

The invention discloses a topological insulator-based all-optical wavelength conversion device. The topological insulator-based all-optical wavelength conversion device comprises an optical fiber, and any section of the optical fiber is manufactured into D-shaped optical fiber or tapering optical fiber; a topological insulator layer is arranged on one plane side of the D-shaped optical fiber or on the waist cone of the tapering optical fiber; the topological insulator layer is 10-50nm thick. The all-optical wavelength conversion device is simple in structure, easy in manufacturing technique, low in noise index, difficult of being influenced by environment temperature, and excellent in stability.