Comparison of methods for landsat TM satellite image segmentation in land cover classification / Landsat TM kosminių nuotraukų segmentavimo metodų palyginimas atliekant žemės dangos klasifikavimą /

Satellite images are the sources of information about the objects on the Earth's surface. However, the practical use of space imagery in Lithuania is still in its infancy. The article presents the segmentation of the satellite image using one of the techniques for digital image classification called supervised classification. Landsat TM digital image classification requiring isolation was carried out using SMAP (sequential maximum a posteriori) and MCL (“maximum likelihood” classifier) segmentation algorithms for the Geographic Information System GRASS (Geographic Resources Analysis Support System) environment. An error matrix (confusion matrix) and kappa coefficients were calculated for accuracy assessment. This study showed that remote sensing and GIS technology are excellent tools for identifying land cover types and calculating their areas. However, to achieve more accuracy employing these methods, additional field investigations will be necessary. Santrauka Kosminiai vaizdai yra vienas iš informacijos šaltinių apie žemės paviršiuje esančius objektus, tačiau praktiškai kosminiai vaizdai Lietuvoje naudojami dar neseniai. Pateiktas kosminio vaizdo segmentavimas taikant vieną iš skaitmeninių vaizdų klasifikavimo metodų – kontroliuojamąjį klasifikavimą (angl. supervised classification). Landsat TM skaitmeninio vaizdo klasifikavimas (nusistatytų klasių išskyrimas) atliktas taikant daugiaspektrius SMAP (sequential maximum a posteriori) ir MCL („maximum likelihood“ classifier) segmentavimo algoritmus geografinės informacinės sistemos GRASS (geographic resources analysis support system – geografinių duomenų analizės palaikymo sistema) aplinkoje. Klasifikavimo tikslumui įvertinti skaičiuota klaidų matrica (confusion ar error matrix) ir kappa koeficientas. Tyrimų duomenys rodė, kad nuotolinio stebėjimo ir GIS technika yra puiki priemonė Žemės dangos tipams identifikuoti ir plotams apskaičiuoti, tačiau aprašytaisiais metodais gautiems rezultatams įvertinti tiksliau būtini lauko tyrimai vietovėje. Резюме Космические изображения являются одним из источников информации об объектах на поверхности земли, однако в Литве использование космических изображений не является распространённым явлением. В статье описывается сегментация космического изображения с использованием одного из методов классификации цифровых изображений – контролируемой классификации (supervised classification). Классификация цифрового изображения Landsat TM (выделение созданных классов) осуществлена с применением многоспектральных алгоритмов сегментации SMAP („sequential maximum a posteriori“) и MCL („maximum likelihood“ classifier) в среде географической информационной системы GRASS (Geographic Resources Analysis Support System). Для оценки точности классификации была рассчитана матрица ошибок (англ. confusion или error matrix) и коэффициент каппа. Исследование показало, что дистанционное наблюдение и техника ГИС являются отличным средством для идентификации типов земельного полога и расчета их площади, однако для более точной оценки результатов, полученных с применением описанных методов, необходимы полевые исследования на местности. Reikšminia žodižiai: kontroliuojamasis klasifikavimas,  Landsat TM skaitmeninis vaizdas, segmentavimas, žemės dangos klasifikavimas,  SMAP (a posteriori nuoseklusis maksimumas),  MLC („didžiausiojo panašumo“ klasifikatorius) Ключевые слова: контролируемaя классификация, цифровое изображение Landsat ТМ, сегментирование, SMAP, MLC  

Impact of modificated asphalt mixtures on paving functioning and environment / Modifikuotų asfaltbetonio mišinių poveikis dangos fukncionavimui ir aplinkai

Atmospheric pollution began to increase in the beginning of 19th century, when the global economy and industrial development started the signal grow. The current problem of global warming is partly related with emission of carbon dioxide (CO2) to environment, which one of the sources are industrial production companies. Warm asphalt mix is usually used in the practice of Lithuania and the world for equipment of road paving. These mixes are produced in specialized asphalt mixers where stone dosing, drying and its mixing with bituminous binders are performed. The temperature of produced hot asphalt mix in mixer reach 150–180 °C and 120–160 °C of mixture laying on the road. Various pollutants, carbon dioxide, formaldehydes, and other are spread to the environment. The carried out researches in Lithuania and the world have showed that while using special additives it is possible to reduce the temperatures of warm asphalt production and laying on the road. Such reduction of temperature helps not to worsen the quality of asphalt layer, to lower the emission of pollutants to environment, to improve the conditions of road workers and to economically use the gas for production of asphalt mixes. Production technologies of different asphalt mixes, their advantages and disadvantages, and results of laboratory tests are analyzed in this article. Equipment samples of experimental road sections, using the warm mixing asphalt mixtures are given. Santrauka  19 amžiaus pradžioje, ėmus sparčiai augti pasaulinei ekonomikai ir vystytis pramonei, pradėjo didėti ir atmosferos užterštumas. Dabartinė globalinė pasaulinio atšilimo problema iš dalies siejama su anglies dioksido (CO2) išmetimu į aplinką, kurio vienas iš šaltinių yra pramoninės gamybos įmonės. Automobilių kelių dangoms įrengti Lietuvos ir pasaulinėje praktikoje dažniausiai naudojami karšto asfalto mišiniai. Šie mišiniai yra gaminami specialiuose asfalto maišytuvuose, kuriuose akmens medžiagos dozuojamos, džiovinamos, maišomos su bituminiais rišikliais. Gaminamo karšto asfalto mišinio temperatūra maišytuve siekia 150–180 oC, o kelyje klojamo – 120–160 oC. Šių procesų metu į aplinką paskleidžiama įvairių teršalų: anglies dioksido, formaldehidų ir kt. Pasaulyje ir Lietuvoje atlikti moksliniai tyrimai parodė, kad naudojant specialius priedus galima sumažinti karštų asfalto mišinių gamybos bei klojimo kelyje temperatūrą. Toks temperatūros sumažinimas leidžia nepabloginti asfalto dangų kokybės, sumažinti teršalų išmetimą į aplinką, pagerinti kelyje dirbančių darbuotojų darbo sąlygas, ekonomiškiau naudoti asfalto mišinių gamybai reikalingas dujas. Šiame straipsnyje analizuojamos skirtingų asfalto mišinių gamybos technologijos, jų privalumai ir trūkumai, laboratorinių bandymų rezultatai. Pateikiami eksperimentinių kelių ruožų įrengimo pavyzdžiai, naudojant šiltojo maišymo asfalto mišinius. Reikšminiai žodžiai: šiltojo maišymo asfaltas, ceolitas, CO2 sumažėjimas

Methods and Criteria for Evaluation of Asphalt Mixture Resistance to Low Temperature Cracking

In cold regions and areas where there is a huge difference between high and low temperatures asphalt pavements are subject to low temperature cracking. The appeared cracks form pavement discontinuities, through which water penetrates into pavement structure. It reduces the bearing capacity of the whole pavement structure, weakens adhesion between bitumen and aggregate, affects bonding between layers and increases the development of frost heaves. A sealing of cracks deals with these issues. However, additional inspections after each winter have to be carried out to identify both cracks that have newly appeared and cracks that need to be resealed. These activities significantly increase road maintenance cost. Selection of the appropriate asphalt mixture by its performance at low temperatures reduces or even prevents low temperature cracking of asphalt pavements. A number of methods such as the Indirect Tensile Test, the Bending Beam Rheometer Test, the Thermal Stress Restrained Specimen Test, Asphalt Thermal Cracking Analyser, the Single-Edge-Notched Beam Test, the Disc-Shaped Compact Tension Test, the Semi-Circular Bend Test, the Fenix Test, Asphalt Concrete Cracking Device and Spectral Analysis of Acoustic Emission are developed to evaluate asphalt mixture resistance to low temperature cracking. This paper presents an analysis of these tests, emphasizes their advantages and disadvantages and gives limiting criteria to evaluate asphalt mixture resistance to low temperature cracking. The test advantages and disadvantages are deciding factors in a test selection. Some tests such as the Thermal Stress Restrained Specimen Test and Spectral Analysis of acoustic emission can directly reveal the lowest temperature at which asphalt mixture can withstand induced thermal stresses

Are rare species useful species? Obstacles to the conservation of tree diversity in the dry forest zone agro-ecosystems of Mesoamerica

Aim To test the potential to conserve rare dry forest tree and shrub species circa situm.Location Oaxaca, Mexico and Southern Honduras.Methods Local uses (timber, posts and firewood) of species were determined principally through semistructured interviews with 20 rural householders in each of four communities in Honduras and four in Oaxaca. Tree and shrub diversity inventories were carried out in a total of 227 forest patches and parcels of farmland in those eight communities. Species’ conservation priorities were determined using the star system of Hawthorne (1996) and IUCN listings.Results Despite a large number of useful species, remarkably few were also conservation priorities. Useful species were found to be substitutable as is illustrated by Bombacopsis quinata, Cordia alliodora, Guaiacum sanctum and G. coulteri.Conclusions In these areas, circa situm conservation is inhibited by the lack of species that are both rare and useful. Usefulness must be interpreted as a function of substitutability. Natural regeneration provides an abundance of diversity, farmers are unlikely to invest in the management of a species when suitable substitutes are freely available. The key to conserving rare species may be in maintaining or enhancing the value of the landscape elements in which they are found

BioTIME:a database of biodiversity time series for the Anthropocene

Abstract Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community‐led open‐source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record. Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km² (158 cm²) to 100 km² (1,000,000,000,000 cm²). Time period and grain: BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year. Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates. Software format: .csv and .SQL