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  • 1
    Publikationsdatum: 2015-09-10
    Beschreibung: In soil proximal sensing with visible and near-infrared spectroscopy, the currently available hyperspectral snapshot camera technique allows a rapid image data acquisition in a portable mode. This study describes how readings of a hyperspectral camera in the 450–950 nm region could be utilised for estimating soil parameters, which were soil organic carbon (OC), hot-water extractable-C, total nitrogen and clay content; readings were performed in the lab for raw samples without any crushing. As multivariate methods, we used PLSR with full spectra (FS) and also combined with two conceptually different methods of spectral variable selection (CARS, “competitive adaptive reweighted sampling” and IRIV, “iteratively retaining informative variables”). For the accuracy of obtained estimates, it was beneficial to use segmented images instead of image mean spectra, for which we applied a regular decomposing in sub-images all of the same size and k-means clustering. Based on FS-PLSR with image mean spectra, obtained estimates were not useful with RPD values less than 1.50 and R2 values being 0.51 in the best case. With segmented images, improvements were marked for all soil properties; RPD reached values ≥ 1.68 and R2 ≥ 0.66. For all image data and variables, IRIV-PLSR slightly outperformed CARS-PLSR.
    Digitale ISSN: 2072-4292
    Thema: Architektur, Bauingenieurwesen, Vermessung , Geographie
    Publiziert von MDPI Publishing
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2015-06-18
    Beschreibung: The hydrodynamics of low-lying riverine floodplains and wetlands play a critical role in hydrology and ecosystem processes. Because small topographic features affect floodplain storage and flow velocity, a hydrodynamic model setup of these regions imposes more stringent requirements on the input Digital Elevation Model (DEM) compared to upland regions with comparatively high slopes. This current study provides a systematic approach to evaluate the required relative vertical accuracy and spatial resolution of current and future satellite-based altimeters within the context of DEM requirements for 2-D floodplain hydrodynamic models. A case study is presented for the Atchafalaya Basin with a model domain of 1190 km2. The approach analyzes the sensitivity of modeled floodplain water elevation and velocity to typical satellite-based DEM grid-box scale and vertical error, using a previously calibrated version of the physically-based flood inundation model (LISFLOOD-ACC). Results indicate a trade-off relationship between DEM relative vertical error and grid-box size. Higher resolution models are the most sensitive to vertical accuracy, but the impact diminishes at coarser resolutions because of spatial averaging. The results provide guidance to engineers and scientists when defining the observation scales of future altimetry missions such as the   Surface Water and Ocean Topography (SWOT) mission from the perspective of numerical modeling requirements for large floodplains of O[103] km2 and greater.
    Digitale ISSN: 2072-4292
    Thema: Architektur, Bauingenieurwesen, Vermessung , Geographie
    Publiziert von MDPI Publishing
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Publikationsdatum: 2013-02-20
    Beschreibung: Background: Identifying similarities and differences in the molecular constitutions of various types of cancer is one of the key challenges in cancer research. The appearances of a cancer depend on complexmolecular interactions, including gene regulatory networks and gene-environment interactions. Thiscomplexity makes it challenging to decipher the molecular origin of the cancer. In recent years,many studies reported methods to uncover heterogeneous depictions of complex cancers, which areoften categorized into different subtypes. The challenge is to identify diverse molecular contextswithin a cancer, to relate them to different subtypes, and to learn underlying molecular interactionsspecific to molecular contexts so that we can recommend context-specific treatment to patients. Results: study, we describe a novel method to discern molecular interactions specific to certainmolecular contexts. Unlike conventional approaches to build modular networks of individual genes,our focus is to identify cancer-generic and subtype-specific interactions between contextual genesets, of which each gene set share coherent transcriptional patterns across a subset of samples,termed contextual gene set. We then apply a novel formulation for quantitating the effect of thesamples from each subtype on the calculated strength of interactions observed. Two cancer data setswere analyzed to support the validity of condition-specificity of identified interactions. Whencompared to an existing approach, the proposed method was much more sensitive in identifyingcondition-specific interactions even in heterogeneous data set. The results also revealed that networkcomponents specific to different types of cancer are related to different biological functions thancancer-generic network components. We found not only the results that are consistent with previousstudies, but also new hypotheses on the biological mechanisms specific to certain cancer types thatwarrant further investigations. Conclusions: The analysis on the contextual gene sets and characterization of networks of interactioncomposed of these sets discovered distinct functional differences underlying various types of cancer. The resultsshow that our method successfully reveals many subtype-specific regions in the identified maps of biologicalcontexts, which well represent biological functions that can be connected to specific subtypes.
    Digitale ISSN: 1471-2164
    Thema: Biologie
    Publiziert von BioMed Central
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Publikationsdatum: 2018-08-10
    Beschreibung: IJERPH, Vol. 15, Pages 1706: Emission Characteristics of Particulate Matter, Volatile Organic Compounds, and Trace Elements from the Combustion of Coals in Mongolia International Journal of Environmental Research and Public Health doi: 10.3390/ijerph15081706 Authors: Mona Loraine M. Barabad Wonseok Jung Michael E. Versoza Minjeong Kim Sangwon Ko Duckshin Park Kiyoung Lee This study characterized emissions of particulate matter (PM), volatile organic compounds (VOCs), heavy metals, and anions from Mongolian bituminous coals in a controlled heating experiment. Three coal samples from Alag Tolgoi (coal 1), Baganuur (coal 2), and Nalaikh (coal 3) were combusted at a constant heat flux of 50 kW/m2 using a dual-cone calorimeter. The coal samples were commonly used in ger district of Ulaanbaatar, Mongolia. PM10 emission factors were 1122.9 ± 526.2, 958.1 ± 584.0, and 472.0 ± 57.1 mg/kg for coal samples 1, 2, and 3, respectively. PM with a diameter of 0.35–0.45 µm was dominant and accounted for 41, 34, and 48% of the total PM for coal samples 1, 2, and 3, respectively. The emissions of PM and VOC from coals commonly used in Ulaanbaatar, Mongolia were significant enough to cause extremely high levels of indoor and outdoor air pollution.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Publikationsdatum: 2018-07-03
    Beschreibung: IJERPH, Vol. 15, Pages 1390: Characteristics of Particulate Matter and Volatile Organic Compound Emissions from the Combustion of Waste Vinyl International Journal of Environmental Research and Public Health doi: 10.3390/ijerph15071390 Authors: Mona Loraine M. Barabad Wonseok Jung Michael E. Versoza Yong-il Lee Kyomin Choi Duckshin Park Vinyl samples were burned in a controlled environment to determine the characteristics of particulate matter (PM) and volatile organic compound (VOC) emissions during the combustion process. Open burning of plastic or vinyl products poses several environmental and health risks in developed and developing countries, due to the release of high concentrations of harmful pollutants. The production of fine and ultrafine particles was significant. At a heat flux of 25 kW/m2, the production of PM of 0.35 μm in size was highest at 63.0 μg/m3. In comparison, at fluxes of 35 and 50 kW/m2, the production of PM of 0.45 μm in size was highest with values of 67.8 and 87.7 μg/m3, respectively. Benzene, acetone, and other toxic compounds were also identified in the analyses.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI Publishing
    Standort Signatur Erwartet Verfügbarkeit
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