Undersea Target Classification Using Canonical Correlation Analysis     

Pezeshki  A. Azimi-Sadjadi  M.R. Scharf  L.L. 《Oceanic Engineering, IEEE Journal of》2007,32(4):948-955

Canonical correlation analysis is employed as a multiaspect feature extraction method for underwater target classification. The method exploits linear dependence or coherence between two consecutive sonar returns, at different aspect angles. This is accomplished by extracting the dominant canonical correlations between the two sonar returns and using them as features for classifying mine-like objects from nonmine-like objects. The experimental results on a wideband acoustic backscattered data set, which contains sonar returns from several mine-like and nonmine-like objects in two different environmental conditions, show the promise of canonical correlation features for mine-like versus nonmine-like discrimination. The results also reveal that in a fixed bottom condition, canonical correlation features are relatively invariant to changes in aspect angle.  相似文献   

Preliminary paleolimnological study of rocha lagoon, SE Uruguay     

Felipe García-Rodríguez  Laura Del Puerto  Carola Castieira  Hugo Inda  Roberto Bracco  Peter Spechmann  Burkhard Wilhelm Scharf 《Limnologica》2001,31(3)

Physical, chemical and biological data from a sedimentary profile of Rocha lagoon (Uruguay) are presented. Analyses of silica remains showed that opal phytoliths, diatoms, sponge spicules and chrysophyte cysts were the most important contributors to biogenic silica. Organic matter, total nitrogen and total phosphorus were used to infer past trophic development. Physical analysis of sediments allowed us to identify five lithological units related to sea level variation and climatic events.  相似文献   

Suburban land conversion in the United States: An economic and governmental process: Clawson,Marion (1971): 406 S., 45 tab., 37 Abb. Baltimore/London: Johns Hopkins Press. $ 12.50     

Burkhard Hofmeister 《Geoforum》1973,4(4):112

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Planning and urban growth. an Anglo-American comparison: CLAWSON,M. and P. HALL (1973): 296 pp., 30 figs., 26 tables. Published for Resources for the Future,Inc. Baltimore/London: The Johns Hopkins Press, £5.65, US$ 12.50     

Burkhard Hofmeister 《Geoforum》1974,5(4):107-108

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Beobachtungen zur Phänologie eines Alpentales     

Burkhard Frenzel  Hermann Fischer 《Theoretical and Applied Climatology》1957,8(2):231-256

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Three-dimensional outlier detection for GPS networks and their densification via the BLIMPBE approach     

Kyle?B.?SnowEmail author  Burkhard?Schaffrin 《GPS Solutions》2003,7(2):130-139

This article discusses outlier detection based on Baarda's theory, but applied to three-dimensional GPS baseline vectors, as compared to the traditional approach of investigating the vector components individually (one-dimensional). In addition, Schaffrin's recently proposed estimator of type BLIMPBE is discussed and contrasted with a minimum constrained least-squares adjustment, specifically Partial-MINOLESS. A more detailed discussion of these topics, which includes additional formulas and derivations, can be found in the first author's Master of Science thesis, hereinafter referred to as Report 465.  相似文献   

A unified scheme for processing GPS dual-band phase observations   总被引：3，自引：4，他引：3  

Burkhard Schaffrin  Yehuda Bock 《Journal of Geodesy》1988,62(2):142-160

A unified computational scheme is presented for sequential least-squares processing ofGPS dual-band carrier-beat-phase observations in network-mode positioning with orbit relaxation, and in orbit determination applications. This scheme is applicable to any spatial and temporal distribution of stations and satellites during a particularGPS experiment. Full covariance matrices can be specified for carrier-beat-phases and for weighted constraints on the ionosphere in order to improve phase ambiguity resolution. Physically meaningful choices for these covariance matrices are developed.  相似文献   

New estimation/prediction techniques for the determination of crustal deformations in the presence of prior geophysical information     

Burkhard Schaffrin 《Tectonophysics》1986,130(1-4):361-367

The estimation of crustal deformations of the Earth from repeated baseline measurements is a singular problem in the absence of prior information. It could be solved by well-known techniques of g-inverse algebra within the framework of a Singular Gauss-Markov Model leading e.g., to BLIMBE (Best Linear Minimum Bias Estimator) or MINOLESS (Minimum NOrm LEast Squares Solution). However, these solutions may not be physically meaningful in view of some independently derived geophysical results. But after introducing these geophysical findings as a-priori information into the linear model, the problem will no longer be singular and can be solved by means of “Improved Linear Estimation” as well as of “Best Linear Prediction”, depending on the way the original model has been expanded. Several alternative estimators and/or predictors are compared with respect to their characterizing properties (homogeneous linear, inhomogeneous linear, biased, unbiased, minimum mean square error, minimum variance, etc.), and the respective gains in efficiency are given.  相似文献   

Decompression experiments as an insight into ascent rates of silicic magmas     

Caroline Martel  Burkhard C. Schmidt 《Contributions to Mineralogy and Petrology》2003,144(4):397-415

An experimental study of H₂O exsolution, bubble growth and microlite crystallisation during ascent (decompression) of silicic magmas in the volcanic conduit is presented. Isobaric and decompression experiments were performed on a rhyolitic melt at 860 °C, NNO+1, H₂O saturation, and pressures between 15 and 170 MPa. Two sets of decompression experiments were performed, with decompression rates varying between 0.001 and 960 MPa/min: (1) from 150 to 50 MPa (high-pressure decompression), and (2) from 50 to 15 MPa (low-pressure decompression). The experiments highlight incomplete H₂O exsolution for decompression rates>100 MPa/min, incomplete bubble growth for decompression rates>0.1 MPa/min, crystal nucleation time lags, and incomplete chemical re-equilibration to final pressures. The observed crystallisation process, i.e. growth versus nucleation, depends on the decompression range. Indeed, decompression-induced crystallisation during high-pressure decompressions is dominated by growth of existing crystals, whereas during low-pressure decompressions crystal nucleation is the dominating process. This study provides a means to infer magma ascent rates in eruptions of silicic magmas through a combined petrologic and experimental approach.  相似文献   

Oxygen,carbon and strontium isotope systematics in two profiles across the Glarus thrust: implications for fluid flow     

Abart  R.  Badertscher  N.  Burkhard  M.  Povoden  E. 《Contributions to Mineralogy and Petrology》2002,143(2):192-208

. The Glarus thrust is a prominent tectonic feature in the eastern Helvetic Alps. It has been recognized as a potential major pathway for syntectonic crustal scale fluid flow. The oxygen, carbon and strontium isotope patterns obtained from two vertical profiles across the thrust indicate fundamentally different flow regimes in the southern section of the thrust, where the footwall is represented by Mesozoic limestones, and in the northern section, where the footwall is represented by Tertiary flysch. At the Grauberg locality in the south, the observed isotope patterns give evidence of a net mass transport component from the hanging wall Verrucano to the footwall limestone with a maximum time-integrated volumetric fluid flux of 6.1 m³/m² In the south, the hydration of the lowermost 10 to 20 m of the hanging wall Verrucano requires introduction of an aqueous fluid by subhorizontal flow along the thrust with a minimum time integrated flux of 240 m³/m². At the Lochseite locality in the north, the isotope patterns indicate a vertical mass transport component from the footwall flysch to the hanging wall Verrucano with a time-integrated fluid flux of 2.6 m³/m². In the north, the fluids were probably derived from compaction and dehydration of the footwall flysch during thrusting. The ascending fluids were ponded below the Verrucano and 'lubricated' the thrust. Short-term pressure drops associated with seismic motion along the thrust led to the precipitation of calcite in veins at the thrust surface contributing material to the Lochseiten calc-mylonite, a thin calc-mylonite layer at the thrust contact. Although cross thrust fluid flow may have been two to three orders of magnitude smaller than flow along the thrust, it had a major impact on the isotopic composition of the Lochseiten calc-mylonite. In particular, it buffered the oxygen isotope composition of the calc-mylonite towards the relatively ¹⁸O-depleted composition of the hanging wall Verrucano in the south and towards the relatively ¹⁸O-enriched compositions of the footwall flysch in the north. By this mechanism a regional south to north ¹⁸O-enrichment trend was simulated within the Lochseiten calc-mylonite.  相似文献