Long-term air temperature variation in the Karkonosze mountains according to atmospheric circulation     

Krzysztof Migała  Grzegorz Urban  Karol Tomczyński 《Theoretical and Applied Climatology》2016,125(1-2):337-351

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Spatial signatures for geographic feature types: examining gazetteer ontologies using spatial statistics   总被引：1，自引：0，他引：1       下载免费PDF全文

Rui Zhu  Yingjie Hu  Krzysztof Janowicz  Grant McKenzie 《Transactions in GIS》2016,20(3):333-355

Digital gazetteers play a key role in modern information systems and infrastructures. They facilitate (spatial) search, deliver contextual information to recommended systems, enrich textual information with geographical references, and provide stable identifiers to interlink actors, events, and objects by the places they interact with. Hence, it is unsurprising that gazetteers, such as GeoNames, are among the most densely interlinked hubs on the Web of Linked Data. A wide variety of digital gazetteers have been developed over the years to serve different communities and needs. These gazetteers differ in their overall coverage, underlying data sources, provided functionality, and geographic feature type ontologies. Consequently, place types that share a common name may differ substantially between gazetteers, whereas types labeled differently may, in fact, specify the same or similar places. This makes data integration and federated queries challenging, if not impossible. To further complicate the situation, most popular and widely adopted geo‐ontologies are lightweight and thus under‐specific to a degree where their alignment and matching become nothing more than educated guesses. The most promising approach to addressing this problem, and thereby enabling the meaningful integration of gazetteer data across feature types, seems to be a combination of top‐down knowledge representation with bottom‐up data‐driven techniques such as feature engineering and machine learning. In this work, we propose to derive indicative spatial signatures for geographic feature types by using spatial statistics. We discuss how to create such signatures by feature engineering and demonstrate how the signatures can be applied to better understand the differences and commonalities of three major gazetteers, namely DBpedia Places, GeoNames, and TGN.  相似文献   

The extended Lissajous–Levi-Civita transformation     

Slawomir Breiter  Krzysztof Langner 《Celestial Mechanics and Dynamical Astronomy》2018,130(10):68

Action-angle variables for the Levi-Civita regularized planar Kepler problem were introduced independently first by Chenciner and then by Deprit and Williams. The latter used explicitly the so-called Lissajous variables. When applied to the transformed Keplerian Hamiltonian, the Lissajous transformation encounters the difficulty of being defined in terms of the constant frequency parameter, whereas the Kepler problem transformed into a harmonic oscillator involves the frequency as a function of an energy-related canonical variable. A simple canonical transformation is proposed as a remedy for this inconvenience. The problem is circumvented by adding to the physical time a correcting term, which occurs to be a generalized Kepler’s equation. Unlike previous versions, the transformation is symplectic in the extended phase space and allows the treatment of time-dependent perturbations. The relation of the extended Lissajous–Levi-Civita variables to the classical Delaunay angles and actions is given, and it turns out to be a straightforward generalization of the results published by Deprit and Williams.  相似文献   

Formation of voids in the Universe within the Lemaître–Tolman model     

Krzysztof Bolejko †  rzej Krasi&#;ski †  Charles Hellaby † 《Monthly notices of the Royal Astronomical Society》2005,362(1):213-228

We develop models of void formation starting from a small initial fluctuation at recombination and growing to a realistic present-day density profile in agreement with observations of voids. The model construction is an extension of previously developed algorithms for finding a Lemaître–Tolman metric that evolves between two profiles of either density or velocity specified at two times. Of the four profiles of concern (those of density and velocity at recombination and at the present day), two can be specified and the other two follow from the derived model.
We find that, in order to reproduce the present-day void density profiles, the initial velocity profile is more important than the initial density profile.
Extrapolation of current cosmic microwave background (CMB) observations to the scales relevant to protovoids is very uncertain. Even so, we find that it is very difficult to make both the initial density and velocity fluctuation amplitudes small enough and still obtain a realistic void by today.  相似文献   

Satellite laser ranging to GPS and GLONASS   总被引：5，自引：4，他引：1  

Krzysztof Sośnica  Daniela Thaller  Rolf Dach  Peter Steigenberger  Gerhard Beutler  Daniel Arnold  Adrian Jäggi 《Journal of Geodesy》2015,89(7):725-743

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Polarization of synchrotron emission from relativistic reconfinement shocks     

Krzysztof Nalewajko 《Monthly notices of the Royal Astronomical Society》2009,395(1):524-530

We study the polarization properties of relativistic reconfinement shocks with chaotic magnetic fields. Using our hydrodynamical model of their structure, we calculate synthetic polarization maps, longitudinal polarization profiles and discuss the spatially averaged polarization degree as a function of jet half-opening angle  Θ _j   , jet Lorentz factor  Γ _j   and observer inclination angle to the jet axis  θ_obs  . We find that for  θ_obs≲Θ _j   the wave electric vectors are parallel in the vicinity of the structure ends and perpendicular in between, while for  θ_obs > Θ _j   the polarization can only be perpendicular. The spatially averaged polarization degree does not exceed 30 per cent. Parallel average polarization, with polarization degrees lower than 10 per cent, has been found for  θ_obs < Θ _j   under the condition  Γ _j Θ _j > 1  . As earlier works predicted the parallel polarization from relativistic conical shocks, we explain our results by discussing conical shocks with divergent upstream flow.  相似文献   

Degradation of Isoprene in the Presence of Sulphoxy Radical Anions     

Krzysztof J. Rudzinski 《Journal of Atmospheric Chemistry》2004,48(2):191-216

Autoxidation of S(IV) initiated by manganese sulphate or potassium peroxydisulphate in alkaline aqueous solutions was significantly slowed down by dissolved isoprene, which decayed in the process. The laboratory experiments were carried out in a batch, perfectly mixed reactor, which had no gas space. The concentration–time profiles of oxygen were measured with a Clark-type electrode. The profiles of sulphite species and of isoprene were evaluated from the UV spectra of solutions. The kinetic analysis indicated that isoprene reacted directly with sulphate radical anions produced during the S(IV) autoxidation. A relative second-order rate constant of (2.12 ± 0.37) × 10⁹ M^–1 s^–1 was determined for this reaction at 25 °C, pH (8.0–8.5) and ionic strength of (1.7–4.9) × 10^–3 M (the reference rate constant of the reaction of sulphate radical anions with sulphite ions equalled 3.4 × 10⁸ M^–1 s^–1). A tentative mechanism of isoprene oxidation during S(IV) autoxidation, which included formation of isoprene – SO^– ₄ adduct, was based on the analogy to the gas-phase reactions of isoprene and to the liquid-phase reactions of sulphate radical anions with other compounds. Atmospheric significance of the aqueous-phase reaction of isoprene with sulphate radicals was discussed. Approximate analysis showed the reaction is a potential sink for isoprene in the aqueous phase and in the gas–liquid systems of high liquid water content (LWC > 10^–5 m³ m^–3). The aqueous-phase oxidation of isoprene can produce secondary pollutants, and influence transformation and the long-range transport of SO₂ in the atmosphere.  相似文献   

Estimation of magnetotelluric transfer functions in the time domain over a wide frequency band     

Krzysztof Nowo&#;y&#;ski 《Geophysical Journal International》2004,158(1):32-41

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Nonlinear Stability of the Lagrangian Libration Points in the Chermnykh Problem   总被引：1，自引：0，他引：1  

Krzysztof Goździewski 《Celestial Mechanics and Dynamical Astronomy》1998,70(1):41-58

In this paper we consider the problem of motion of an infinitesimal point mass in the gravity field of an uniformly rotating dumb-bell. The aim of our study is to investigate Liapunov stability of Lagrangian libration points of this problem. We analyze the stability of libration points in the whole range of parameters ω, μ of the problem. In particular, we consider all resonance cases when the order of resonance is not greater than five. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

A Lower Palaeozoic shallow water sequence in the eastern European Variscides (SW Poland): provenance and depositional history     

Kryza  Ryszard  Turniak  Krzysztof  Muszyński  Andrzej  Zalasiewicz  Jan A. 《International Journal of Earth Sciences》1994,83(1):5-19

The Gackowa Formation of inferred Cambrian —Ordovician age is part of the metamorphosed pre-Variscan basement of the southern Kaczawa Mountains of the Sudetes region, south-west Poland. Previously variously interpreted as lavas, tuffs and sandstones, it is shown to consist of about 200 m of originally well-sorted siliclastic sedimentary rocks within a sequence of predominantly mafic volcanic rocks. Four facies have been distinguished based on relict sedimentary structures and textures and these suggest that deposition took place on a storm-dominated shelf, mostly above the wave base. The petrography, detrital zircon morphologies and geochemistry suggest affinity with, and derivation in large part from, acid volcanic rocks at a comparable stratigraphic position in a separate tectonostratigraphic unit to the south. The Gackowa Formation and its acid volcanic source rocks have a clear continental geochemical signature, in contrast with the mantle-derived basic/bimodal volcanic rocks below and above; it is suggested that the parent acid magma originated by crustal melting during the ascent of these mantle-derived magmas. A continental crust setting is inferred for the deposition of the Gackowa Formation sandstones, thus suggesting a continental setting for the associated within-plate basalts. The entire volcanic/sedimentary succession resembles elements of the Lower Palaeozoic of Germany, and all may have formed in an initial rift setting during Late Precambrian to Ordovician times.  相似文献