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Continuous flow injection and UV spectrophotometric detection have been proposed for simultaneous determination of the two binary mixtures, butylated hydroxytoluene (BHT)/n-propyl gallate (n-PG) and butylated hydroxytoluene (BHT)/butylated hydroxyanisole (BHA), in food and cosmetics samples. The method is based on the different residence times of each antioxidant when the flow cell is packed to a height of 25 mm with silica C18 using methanol-water 50:50% (v/v) as a carrier with a flow rate of 1.25 and 1.10 ml min−1, respectively. The determination of each antioxidant is based on the measurement of its absorbance at its maximum wavelengths using a DAD detector at 30 and 180 s for the mixture n-PG-BHT and 90 and 220 s for BHA-BHT. Calibration graphs were linear over the range 10.0-300.0 μg ml−1 for each antioxidant in both mixtures. The relative standard deviations were 2.5% for BHT and 2.0% for the co-existing antioxidant. Resolution of the n-PG-BHT mixture in ratios between 1:8 and 8:1 and the BHA-BHT mixture in ratios between 1:10 and 10:1 is possible. The method was applied to the determination of both antioxidants in fat foods and cosmetics samples with recoveries ranging between 101 and 105%. 相似文献
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Multidimensional assignment formulation of data association problems arising from multitarget and multisensor tracking 总被引:4,自引:0,他引:4
Aubrey B. Poore 《Computational Optimization and Applications》1994,3(1):27-57
The ever-increasing demand in surveillance is to produce highly accurate target and track identification and estimation in real-time, even for dense target scenarios and in regions of high track contention. The use of multiple sensors, through more varied information, has the potential to greatly enhance target identification and state estimation. For multitarget tracking, the processing of multiple scans all at once yields high track identification. However, to achieve this accurate state estimation and track identification, one must solve an NP-hard data association problem of partitioning observations into tracks and false alarms in real-time. The primary objective in this work is to formulate a general class of these data association problems as multidimensional assignment problems to which new, fast, near-optimal, Lagrangian relaxation based algorithms are applicable. The dimension of the formulated assignment problem corresponds to the number of data sets being partitioned with the constraints defining such a partition. The linear objective function is developed from Bayesian estimation and is the negative log posterior or likelihood function, so that the optimal solution yields the maximum a posteriori estimate. After formulating this general class of problems, the equivalence between solving data association problems by these multidimensional assignment problems and by the currently most popular method of multiple hypothesis tracking is established. Track initiation and track maintenance using anN-scan sliding window are then used as illustrations. Since multiple hypothesis tracking also permeates multisensor data fusion, two example classes of problems are formulated as multidimensional assignment problems.This work was partially supported by the Air Force Office of Scientific Research through AFOSR Grant Numbers AFOSR-91-0138 and F49620-93-1-0133 and by the Federal Systems Company of the IBM Corporation in Boulder, CO and Owego, NY. 相似文献
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一种有效的不同类型传感器多目标跟踪融合算法 总被引:5,自引:1,他引:5
提出了不同类型传感器多目标跟踪的一种改进的分层融合算法,该算法不仅适合于不同类型同步数据融合,而且适合于不同类型传感器异步数据融合。仿真结果显示了该融合算法的有效性。 相似文献
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《Electroanalysis》2017,29(9):2161-2166
A multivariate calibration of multisensor systems is a very important stage in their application. Construction of reliable calibration model requires significant investment of time and money. Once established, calibration model can be applied normally only together with that particular multisensor system, which was employed for its’ construction – this can be a serious limitation for a wide adoption of multisensor systems in common laboratory practice. In order to address this issue we have studied the applicability of several calibration transfer techniques, such as direct standardization, single wavelength standardization and standardization with regularization coefficient for the data obtained from two potentiometric multisensor systems in analysis of complex lanthanide mixtures. It was found that mathematical correction of sensor array response using standardization with regularization coefficient allows for using the regression model derived for one sensor array together with the data obtained from another sensor array. The value of root mean squared error of prediction for total lanthanide concentration increased insignificantly (0.10 instead of 0.07 in log scale) compared with that provided by the first multisensor system. 相似文献
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The electronic tongue (ET) multisensor system has been employed for the detection of metal-oxygen cluster anions (polyoxometalates) containing vanadium (IV/V) atoms. Sensitivity of a variety of potentiometric chemical sensors with plasticized polyvinyl chloride and chalcogenide glass membranes was evaluated with respect to vanadyl/vanadate ions, decavanadate and a series of Keggin-type polyoxometalates (POM) such as α-[SiW11VIVO40]6−, α-[SiW11VVO40]5−, α-[BW11VIVO40]7−, α-[BW11VVO40]6−, α-[PW11VIVO40]5− and α-[PW12−nVnVO40](3+n)− (n = 1, 2, 3). Sensor's responses to vanadium complexes were evaluated in the pH range of 2.4-6.5 and a set of sensors appropriate for detecting a variety of vanadium species was selected. Such sensor array was able to distinguish different vanadium complexes allowing their simultaneous quantification in binary (V(IV)/V(V)) mixtures. The vanillyl alcohol oxidation with α-[SiW11VVO40]5− was monitored using ET to evaluate the capacity of proposed analytic system to detect simultaneously V(IV)/V(V) in POM under dynamic equilibrium. ET was demonstrated to be a promising tool for the discrimination and quantification of vanadium-containing POMs at different oxidation states. In particular, such a system could represent a significant interest for the mechanistic studies of redox reactions with POMs. 相似文献
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Ram M. Narayanan Sandy R. Jackson 《International Journal of Infrared and Millimeter Waves》1997,18(5):959-990
Knowledge of surficial snow properties such as grain size, surface roughness, and free-water content provides clues to the
metamorphic state of snow on the ground, which in turn yields information on weathering processes and climatic activity. Remote
sensing techniques using combined concurrent measurements of near-infrared passive reflectance and millimeter-wave radar backscatter
show promise in estimating the above snow parameters. Near-infrared reflectance is strongly dependent on snow grain size and
free-water content, while millimeter-wave backscatter is primarily dependent on free-water content and, to some extent, on
the surface roughness. A neural-network based inversion algorithm has been developed that optimally combines near-infrared
and millimeter-wave measurements for accurate estimation of the relevant snow properties. The algorithm uses reflectances
at wavelengths of 1160 nm, 1260 nm and 1360 nm, as well as co-polarized and cross-polarized backscatter at a frequency of
95 GHz. The inversion algorithm has been tested using simulated data, and is seen to perform well under noise-free conditions.
Under noise-added conditions, a signal-to-noise ratio of 32 dB or greater ensures acceptable errors in snow parameter estimation. 相似文献
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《Electroanalysis》2017,29(10):2232-2238
Human saliva is one of the body fluids which collection method is relatively simple and non‐invasive. The article is dedicated to assess concentration (activity) of Na+, K+, Ca2+, Mg2+ and Cl− in fresh, unstimulated or stimulated human saliva samples using single solid contact ion‐selective electrodes with conventional reference electrode and self‐made multisensor platform (MP) equipped with ion‐selective membranes for Na+, K+, Ca2+, Mg2+ and Cl− and reference electrode made in solid state technology, based on dispersed KCl in the polymer. Both kind of electrodes, single ISE and miniaturized electrodes in multisensor platform (ISE‐MP) were made of glassy carbon. The electrode surfaces have been modified by conductive polymer (PEDOT) layer deposition; with the exception of Cl− electrode, in which conducting polymer was not applied. Potentiometric measurements were used to compare the changes of the ionic composition in various samples of saliva. 相似文献
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为解决目前基层军营安全监测手段存在的高功耗、高成本、实时性较差、易被破坏等问题,选用CC2531和CC2591作为ZigBee通信模块芯片,布设多种传感器,搭建无线传感网,以PC机为监测主机,制定通信协议,设计出军营无线安全监测与预警系统;实现一平方公里范围内温度、湿度、人体入侵、可燃气体烟雾浓度等信息的远程监测与自动预警;以不同距离监测哈尔滨十二月份室外温度、相对湿度为试验,无数据丢失,温湿度测量误差不大于2%,表明系统具有高可靠性、高精度、低功耗、灵活易用等优点,具有广阔的应用前景。 相似文献