摘要:
A given volume of a test substance is provided into a monitoring line which is filled with a test medium (e.g. air). The line extends along a path for determining concentration profiles of certain substances along the path. For the purpose of transporting a column of test medium through the monitoring line, the pressure in the monitoring line is increased by switching on a pressure pump or, for the same purpose--in an alternative embodiment--the pressure is reduced by switching on a suction pump. A given metering volume of the test substance is automatically released in the monitoring line when the pressure goes beyond a given pressure threshold. The release of the given metering volume of the test substance, after it has been carried along the monitoring line by the column of test medium, results in a test peak for reference reading calibration in a sensor which responds to the test substance and which is connected to the monitoring line.
摘要:
A device and a method for leakage detection and leakage location in an installation, in particular in a pipeline, include a collecting line which is permeable to a substance and is connected to a pump and to a sensor for the substance. A metal wire is disposed outside and along the collecting line and is connected to a negative pole of a direct current source. When a solution, for example salt water, emerges from a leak in a pipeline, a gas, in particular hydrogen, is obtained by electrolysis at the metal wire. A concentration maximum of the gas in the collecting line is then detected and located.
摘要:
The apparatus enables accurate determination of concentration profiles of liquid or gaseous substances along a given path. A partially permeable line segment is laid along the route and the substances to be detected are allowed to penetrate into its interior. The line is filled with a test medium, and the column of the test medium is forced through the line at chronological intervals and moved past a sensor that is sensitive to the substances. A first closure is incorporated between the sensor and the line, and one or more closures are incorporated into the line to maintain the column of test medium substantially stationary in a position of repose of the system.
摘要:
A method for locating an accumulation of pollutants includes continuously guiding a conveying medium in mutually opposite directions through two legs of a pollutant-permeable collecting line, the legs being placed closely adjacent and mutually parallel as forward and return lines. A detection is performed as to whether or not the conveying medium contains a pollutant at an outlet of the collecting line. A location of an accumulation of pollutants at the collecting line is determined from a difference in time between two successive pollution detections at the outlet of the collecting line. A device for locating accumulations of pollutants includes a collecting line being permeable to a pollutant and having two legs being closely adjacent, mutually parallel and switched as forward and return lines. A continuously operating pump is connected to the collecting line for conveying a conveying medium through the collecting line. A sensor is connected to the collecting line for detecting a pollutant. An evaluation unit is connected to the sensor.
摘要:
A flexible sensor tube for determining a concentration curve of a medium along a path includes a flexible tube being formed of a material having good permeability to the medium and having an inner surface being completely provided with a thin coating of a material having poor permeability to the medium. A flexible tube of a material having good permeability to the medium may also be coated on the inner surface with a material being impermeable or having poor permeability to the medium, with a narrow strip extending in the longitudinal direction of the flexible tube being left free. In addition, a band being formed of a material being impermeable or having poor permeability to the medium, can be bent into the shape of a trough, while a slot-like aperture remains free. The slot-like aperture is closed by a strip being formed of a material having good permeability to the medium and extending in the longitudinal direction of the band.
摘要:
A two-layer hierarchical audio bit stream can have a frame-based structure for the base layer bit stream and can be decoded independently from a higher layer and the decoding can start following every sync header. In the extension layer bit stream the frame structure may not be reflected on bit stream level. To facilitate seek operations with such highly compressed extension-layer data, the header of the extension layer bit stream comprises an FAT table with seek target positions. Because there are fewer entry points in the enhancement layer than sync headers in the base layer, a re-synchronization and some base layer frames are required to start decoding of the enhancement layer and to generate the full audio quality. Three seeking ways of seeking are described, of which each one offers a different compromise between seeking accuracy, re-synchronization latency and audio quality.
摘要:
With quantisation index modulation QIM it is possible to achieve a very high data rate, and the capacity of the watermark transmission is mostly independent of the characteristics of the original audio signal, but the audio quality suffers from degradation with each watermark embedding-and-removal step. In order to avoid degradation of the audio quality, the inventive audio signal watermarking uses specific quantiser curves in time domain and in particular in frequency domain for embedding the watermark message into the audio signal, whereby the processing is almost perfectly reversible. Furthermore, it has embedded a power constraint in order to guarantee that the modifications of the audio signal due to the watermark embedding are inaudible.
摘要:
Filter banks may have different structures and different individual output signal domains. Often a translation between different filter bank domains is desirable. Usually, mapping matrices are used that, however, vary over frequency. This requires a significant amount of lookup tables. A method for transforming first data frames of a first filter bank domain to second data frames of a different second filter bank domain, comprises steps of transcoding sub-bands of the first filter bank domain into sub-bands of an intermediate domain that corresponds to said second filter bank domain but has warped phase, and transcoding the sub-bands of the intermediate domain to sub-bands of the second filter bank domain, wherein a phase correction is performed on the sub-bands of the intermediate domain.
摘要:
Lossless audio coding performs decorrelation and encodes the transformed signal. The encoded bit stream comprises de-correlation parameters and the lossless representation data of the transformed signal. However, in the case of lossy based lossless coding, the additional amount of information exceeds the base layer amount of data. Therefore the additional data cannot be packed completely into the base layer e.g. as ancillary data. The data streams resulting from the combination of lossy coding format with a lossless coding extension are the base layer containing the lossy coding information and the enhancement data stream for rebuilding the mathematically lossless original input signal. Every higher layer depends on the lower layers and can only be reasonably decoded in combination with these lower layers. According to the invention, a special combination of one-time header information with repeated header information in a block structure is used. Assignment information data identify the different layers.
摘要:
An audio signal may have a BL and an EL, wherein the EL represents additional information for enhancing the quality of the BL audio content. Decoding of such dual-layer signals usually comprises partial decoding of the BL data, wherein frequency bins of the BL are restored, mapping the restored frequency bins to the MDCT domain, adding them to the decoded EL and performing inverse Integer MDCT. A low-complexity method for decoding comprises reverse mapping of the decoded EL data, adding the reverse mapped EL data to the partially decoded BL data and filtering the sum, using the inverse BL filter bank.