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Wyszukujesz frazę "canopy" wg kryterium: Temat


Tytuł:
Relationship between forest canopy and natural regeneration in the subalpine spruce-larch forest (north-east Italy)
Autorzy:
Marchi, A.
Paletto, A.
Powiązania:
https://bibliotekanauki.pl/articles/38768.pdf
Data publikacji:
2010
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
relationship
forest canopy
natural regeneration
subalpine forest
spruce-larch forest
canopy closure
canopy cover
Italy
Opis:
The authors describe the difference between canopy cover (proportion of the forest floor covered by the vertical projection of the tree crowns) and canopy closure (proportion of sky hemisphere obscured by vegetation when viewed from a single point) and the respective ground-based estimation techniques focused on two types of densiometer (GRS tube and spherical). The data collected in the field were used to analyse the relationship between forest canopy and natural regeneration in two subtypes of subalpine larch-spruce forests. The results indicate that in the first subtype characterized by a high fertility and a high canopy cover (around 62%), the level of natural regeneration is low (115 stems per hectare) and it is nearly exclusively composed by spruce [Picea abies (L.) Karst.]. For the second subtype characterized by a low fertility and a medium canopy cover (around 49%) the natural regeneration is rather dense (650 stems per hectare). At last the authors evidence a insignificant difference between the data of forest canopy collected by different ground-based estimation techniques (+0.7% using spherical densiometer compared to using GRS tube densiometer).
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2010, 52, 1
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calibration and Evaluation of Aquacrop for Maize (Zea Mays L.) under Different Irrigation and Cultivation Methods
Autorzy:
Hassan, Diaa Fliah
Ati, Alaa Salih
Neima, AbdulKhalik Saleh
Powiązania:
https://bibliotekanauki.pl/articles/2027849.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
Aquacrop
sprinkler irrigation
canopy cover
maize
Opis:
Crop models of simulation are utilised effectively to evaluate the management of irrigation strategies which help in managing the water use. The aim of this study was to verify the validity of the Aquacrop model of maize under the surface and sprinkler irrigation systems, and a cultivation system, borders and furrows, and for two varieties of Maze (Fajr and Drakma) at two different sites in Iraq, i.e. the Babylon and Al-Qadisiyah governorates. The current study conducted an experiment to evaluate the Aquacrop model capacity in simulating canopy cover (CC), biomass (B), dry yield, harvest index (HI), and water productivity (WP). The results of RMSE, R2, MAE, d, NSE, CC, Pe indicated good results and high compatibility between the measured and simulated values. The highest achieved results were identical to the method of sprinkler irrigation due to the decrease in the amount of water consumed and the furrows cultivation method as the aerial roots were covered and the cultivar was Drakma. The highest values for the statistical data were $R^2$ (90 and 96%), RMSE (0.60, 0.73), MAE (0.5, 0.67), d (0.97, 0.97), NSE (0.87, 0.90), for the Babylon and Al-Qadisiyah sites, respectively. As for the CC values, they were very compatible with the values of $R^2$ and ranged between (92–99)%. The prediction error was Pe and minor errors were found. Thus, the Aquacrop model can be used reliably to evaluate the effectiveness of proposed irrigation management strategies for maize.
Źródło:
Journal of Ecological Engineering; 2021, 22, 10; 192-204
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie chmury punktów ze skaningu laserowego w obszarze koron drzew
The lidar point cloud data-based forest canopy modelling
Autorzy:
Wężyk, P.
Powiązania:
https://bibliotekanauki.pl/articles/130582.pdf
Data publikacji:
2008
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
lotniczy skaning laserowy
ALS
inwentaryzacja lasu
wysokość drzew
podstawa korony
powierzchnia warstwy koron
objętość warstwy koron
forest inventory
tree height
canopy base
canopy surface
canopy volume
Opis:
Celem pracy było określenie przydatności i zaproponowanie rozwiązań automatyzacji procesu określania wybranych parametrów taksacyjnych drzewostanów związanych z koronami drzew, w oparciu o dane z lotniczego skaningu laserowego (ALS). Analiza przydatności danych ALS bazuje na pomiarach referencyjnych 432 sosen w obszarze badawczym Milicz (RDLP Wrocław). Osiągnięte wyniki wskazują, iż: (1) wysokość pojedynczych drzew określona na podstawie modelowanej chmury punktów ALS w zależności od użytego algorytmu, prowadzi do niewielkiego zaniżenia wartości (średnia różnica -0.90 m CHM1 lub -0.12 m CHM2); (2) średnia wysokość analizowanych drzewostanów na powierzchniach kołowych określana na podstawie ALS, była wyższa (+0.85 m) od wartości zapisanych w bazie danych SILP (2005) co w efekcie prowadzić może do zaniżenia zasobności drzewostanów w całym obrębie; (3) automatycznie analizowana średnia wysokość drzewostanów sosnowych (95 centyl FE) była wyższa o +0.46 m w stosunku do danych z SILP; (4) automatycznie określona podstawa korony sosny wykazuje błąd zaledwie około 0.56 m; (5) analiza histogramów chmury punktów umożliwiła określenie długości korony z przeszacowaniem o +0.44 m w stosunku do danych referencyjnych; (6) modelowanie warstwy koron otwiera dyskusje na temat homogeniczności jednowiekowych i jednogatunkowych pododdziałów oraz istniejącego podziału przestrzennego. Nowa metoda inwentaryzacji leśnej bazująca na technologii pozyskiwania danych ALS i modelowaniu chmury punktów ma duże szanse na wdrożenie w lasach Polski o powinno przynieść ze sobą wzrost dokładności jak i obniżyć koszty prac urządzeniowych.
The study was aimed at determining the utility of and to improve the understanding of the airborne laser scanning (ALS) technology in acquisition of selected parameters of canopy layers for individual trees and whole stands. This approach, based on ALS data (TopoSys fiber scanner; swing mode + optical line scanner), was compared with reference data drawn from a forest inventory (432 Scots pines). The study showed that: (1) the height of a single tree, as derived from ALS data, leads to underestimation (mean difference -0.90 m or +0.12 m depending on CHM generation algorithm); (2) the mean stand height was higher (+0.85 m) than the height recorded in the SILP database, which may result in underestimation of the timber volume in the entire Milicz forest district; (3) the stand mean height (understood as 95th percentile of the FE point cloud) was +0.46 m higher than the height recorded in the SILP inventory database; (4) it was possible to estimate the canopy base with 0.56 m overestimation; (5) the canopy length as measured during the forest inventory was +0.44 m lower compared to the ALS data (histogram analysis); (6) the homogeneity of a contemporaneous-pine stand is questionable. In a very near future, a new approach to the forest inventory, supported by ALS data, will be presented as a list of new parameters and guidelines.
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2008, 18b; 685-695
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Absorbtion of the photosynthetically active radiation (PAR) in canopy and yield formation by leafy and semi-leafless morphotypes of the pea plant (Pisum sativum L.).
Autorzy:
Czerednik, Anna
Nalborczyk, Emil
Powiązania:
https://bibliotekanauki.pl/articles/2198789.pdf
Data publikacji:
2000-12-20
Wydawca:
Instytut Hodowli i Aklimatyzacji Roślin
Tematy:
biomass accumulation
canopy
radiation interception
pea
RUE
Opis:
An experiment aimed to review differences in the pattern of canopy forming, solar radiation penetration and its use efficiency (RUE) within the canopy of two contrasting pea morphotypes (leafy and semi-leafless) was conducted in the field. The differences in absorption of PAR were significant for both morphotypes in two consecutive years of different climatic conditions. The canopy architecture influenced absorption of PAR, penetration through the canopy and can cresult in different yield forming. For both morphotypes a common linear correlation between intercepted PAR and dry matter accumulation was found until the beginning of pod formation, but then this association was not linear. Differences in CGR and ULRc were significantly bigger in leafy pea morphotypes than in semi-leafless one and the higher values for both were observed at the beginning of pod formation.
Źródło:
Plant Breeding and Seed Science; 2000, 44; 85-93
1429-3862
2083-599X
Pojawia się w:
Plant Breeding and Seed Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aerodynamics of the City
Aerodynamika miasta
Autorzy:
Kozaczko, Mieczysław
Powiązania:
https://bibliotekanauki.pl/articles/2034269.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
City aerodynamics
urban canopy
aerodynamika miasta
miejska sfera
Opis:
The “input-output desideratum”, outlined in the New Athens Charter, sets new requirements for urban designers. Nowadays, using modern techniques, we can solve weighty contemporary urban problems using such system of designing, which balances quantitative and qualitative parameters of the urban matter. The text presents the part of the designing system that uses methodology of the meteorology. Proper use of this system allows to control and design parameters of the socalled urban canopy. The urban canopy covers the area of reduced energy consumption and increased comfort of using the public space between the buildings constituting urban tissue. Urban canopy is characterized by multiplier effects, obtained - among others - thanks to the use of aerodynamics in urban design. Shaping buildings, supported by empirical method (with use of models), allows to implement the so-called filters and regulators postulated in the Charter: the elements that maintain the city's structure in balance.
Dezyderat input-output, naszkicowany w Nowej Karcie Ateńskiej stawia przed projektantami miast nowe wymagania. Może im sprostać system projektowania urbanistycznego, operujący balansem przestrzennych jakości z energetycznymi ilościami. Niniejszy tekst prezentuje tę część systemu, która w projektowaniu wykorzystuje metodologię meteorologiczną. Właściwe użycie jej aparatu umożliwia kontrolę i projektowanie parametrów tzw. miejskiej sfery. Miejska sfera jest obszarem o obniżonej energochłonności oraz podwyższonym komforcie użytkowania między budynkowej przestrzeni publicznej. Charakteryzują go efekty mnożnikowe, uzyskane – między innymi – dzięki wykorzystaniu aerodynamiki w projektowaniu urbanistycznym. Kształtowanie zabudowy, wspomagane metodą empiryczną (z użyciem modelu), pozwala realizować postulowane w Karcie filtratory i regulatory: elementy utrzymujące strukturę miasta w równowadze.
Źródło:
Przestrzeń i Forma; 2021, 46; 103-116
1895-3247
2391-7725
Pojawia się w:
Przestrzeń i Forma
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water-borne hyphomycetes in tree canopies of Kaiga (Western Ghats), India
Autorzy:
Sudheep, N.M.
Sridhar, K.R.
Powiązania:
https://bibliotekanauki.pl/articles/67068.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
water-borne hyphomycete
hyphomycete
diversity
conidium
leaf litter
sediment
stemflow
tree canopy
Kaiga
Western Ghats
India
life cycle
aquatic habitat
canopy
Opis:
The canopy samples such as trapped leaf litter, trapped sediment (during summer), stemflow and throughfall (during monsoon) from five common riparian tree species (Artocarpus heterophyllus, Cassia fistula, Ficus recemosa, Syzygium caryophyllatum and Xylia xylocarpa) in Kaiga forest stand of the Western Ghats of southwest India were evaluated for the occurrence of water-borne hyphomycetes. Partially decomposed trapped leaf litter was incubated in bubble chambers followed by filtration to assess conidial output. Sediments accumulated in tree holes or junction of branches were shaken with sterile leaf disks in distilled water followed by incubation of leaf disks in bubble chamber and filtration to find out colonized fungi. Stemflow and throughfall samples were filtered directly to collect free conidia. From five canopy niches, a total of 29 water-borne hyphomycetes were recovered. The species richness was higher in stemflow and throughfall than trapped leaf litter and sediments (14-16 vs. 6-10 species). Although sediments of Syzygium caryophyllatum were acidic (5.1), the conidial output was higher than other tree species. Stemflow and throughfall of Xylea xylocarpa even though alkaline (8.5-8.7) showed higher species richness (6-12 species) as well as conidial load than rest of the tree species. Flagellospora curvula and Triscelophorus acuminatus were common in trapped leaf litter and sediments respectively, while conidia of Anguillospora crassa and A. longissima were frequent in stemflow and throughfall. Diversity of water-borne hyphomycetes was highest in throughfall of Xylea xylocarpa followed by throughfall of Ficus recemosa. Our study reconfirms the occurrence and survival of diverse water-borne hyphomycetes in different niches of riparian tree canopies of the Western Ghats during wet and dry regimes and predicts their possible role in canopy as saprophytes, endophytes and alternation of life cycle between canopy and aquatic habitats.
Źródło:
Acta Mycologica; 2010, 45, 2
0001-625X
2353-074X
Pojawia się w:
Acta Mycologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Road network partitioning method based on Canopy-Kmeans clustering algorithm
Autorzy:
Lin, Xiaohui
Xu, Jianmin
Powiązania:
https://bibliotekanauki.pl/articles/949836.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic engineering
road network
road network partition
Canopy-Kmeans algorithm
macroscopic fundamental diagram
inżynieria ruchu
sieć drogowa
sterowanie siecią drogową
algorytm Canopy-Kmeans
Opis:
With the increasing scope of traffic signal control, in order to improve the stability and flexibility of the traffic control system, it is necessary to rationally divide the road network according to the structure of the road network and the characteristics of traffic flow. However, road network partition can be regarded as a clustering process of the division of road segments with similar attributes, and thus, the clustering algorithm can be used to divide the sub-areas of road network, but when Kmeans clustering algorithm is used in road network partitioning, it is easy to fall into the local optimal solution. Therefore, we proposed a road network partitioning method based on the Canopy-Kmeans clustering algorithm based on the real-time data collected from the central longitude and latitude of a road segment, average speed of a road segment, and average density of a road segment. Moreover, a vehicle network simulation platform based on Vissim simulation software is constructed by taking the real-time collected data of central longitude and latitude, average speed and average density of road segments as sample data. Kmeans and Canopy-Kmeans algorithms are used to partition the platform road network. Finally, the quantitative evaluation method of road network partition based on macroscopic fundamental diagram is used to evaluate the results of road network partition, so as to determine the optimal road network partition algorithm. Results show that these two algorithms have divided the road network into four sub-areas, but the sections contained in each sub-area are slightly different. Determining the optimal algorithm on the surface is impossible. However, Canopy-Kmeans clustering algorithm is superior to Kmeans clustering algorithm based on the quantitative evaluation index (e.g. the sum of squares for error and the R-Square) of the results of the subareas. Canopy-Kmeans clustering algorithm can effectively partition the road network, thereby laying a foundation for the subsequent road network boundary control.
Źródło:
Archives of Transport; 2020, 54, 2; 95-106
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sezonowy przebieg wskaźnika wykorzystania wody (WUE) w lesie sosnowym
Seasonal Water Use Efficiency (WUE) Index Course in Pine Forest
Autorzy:
Ziemblińska, K.
Urbaniak, M.
Danielewska, A.
Baran, M.
Juszczak, R.
Chojnicki, B. H.
Olejnik, J.
Powiązania:
https://bibliotekanauki.pl/articles/1819204.pdf
Data publikacji:
2013
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
wykorzystanie wody
lasy sosnowe
flux measurements
carbon
exchange
canopy
heat
Opis:
Assessment of the ecosystem productivity in relation to the amount of water used for such kind of processes have already been investigated for the different ecosystem types by many researchers. Water Use Efficiency (WUE) parameter shows seasonal variation due to changing weather conditions, which determine processes of photosynthesis, respiration and evapotranspiration, and because of biological factors variability. The analysis of the WUE dynamics in the forest ecosystem in Tuczno research station over the hydrological year 2012 were presented in the paper. WUE was calculated based on the daily CO2 and H CO2 O fluxes measured by means of the eddy covariance system (EC) installed over the forest canopy. The fluxes were quality checked in relation to the wind direction, friction velocity values and stationary. The data series used in this investigation were not gap-filled. By using the net value of both fluxes, a good indicator which describe the behavior of the ecosystem as the whole, was obtained. Among a number of weather condition factors, that affect the value of the tested indicator (WUE), mainly photosynthetic photon flux density (PPFD) and the air temperature were evaluated. Separate analysis has been done for daily courses of both CO2 and H2 O fluxes, as well as for WUE for each month of the analyzed period. The highest values of H2 O fluxes (FH) were observed in May and June (0.25 and 0.3 kg m-2s-1) and the lowest in the period from September to December (0.02–0.05 kg m-2s-1). The daily courses of water vapor fluxes revealed dependence to the measured PPFD fluxes, which determines in turn the intensity of the evapotranspiration process. The time courses of the daily 30-min average carbon dioxide fluxes (FC) were also highly variable in each month, similarly to the variances of the FH fluxes. The lowest values of the net F COC were measured in the period from October to December (net CO2 fluxes did not exceed 0.55g m-2 s-1), while in the period from April to July the net ecosystem productivity was the biggest (1.5–2.0 m-2s-1),). WUE reached its minimum in May (7 g [CO2] kg-1), [H2O]), what indicates that the evapotranspiration of the ecosystem was the least effective from the point of view of COCOD absorption from the atmosphere (the ecosystem had a high productivity but it lost a great amount of water at the same time). In contrary, higher WUE values were observed in the colder period of the year, when the amount of available radiant energy was limited. WUE reached its peak in September (nearly 45 g of [CO2] kg-1), [H2O] ) which reveals, that in autumn the decline of evapotranspiration rates were higher than rates of the net CO2 exchange decrease. It also highlights the high adaptability of Scots pine (main species in studied forest ecosystem – 99%), to described conditions. The designated water use efficiency (WUE) parameter, may be used as a good indicator of the current condition of the ecosystem.
Źródło:
Rocznik Ochrona Środowiska; 2013, Tom 15, cz. 3; 2780-2798
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reed canopy transparency under different levels of diffuse radiation
Przezroczystość trzcinowiska w różnych warunkach rozproszenia promieniowania słonecznego
Autorzy:
Harenda, K.
Piatyszek, M.
Chojnicki, B.H.
Powiązania:
https://bibliotekanauki.pl/articles/36026.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
diffuse radiation
solar radiation
reed
leaf area index
ecosystem
canopy
Opis:
Diffused solar radiation increases ecosystem productivity. One of the explanations for this phenomenon is the fact that this type of radiation penetrates the vegetation layer more efficiently, thus changing radiation conditions under the plant canopy. The study of reed transparency under different radiation diffusion conditions makes it possible to estimate the amount of radiation energy that reaches plants living under the reed canopy. The presented radiation parameters were obtained using the SS1 probe (Delta-T Devices Ltd. UK.). The measurements were carried out in September 2014 in a reed canopy in the Rzecin peatland (52°45′N, 16°18′E, 54 m a.s.l.). Analyses showed that the transparency of the reed canopy (Tr) is directly proportional to the degree of diffusion (D*) of the radiation which reaches the plant surface and the reed Tr value is always greater at cloudy conditions than during periods of low radiation diffusion. At the same time, Tr is inversely proportional to the leaf area index (LAI). Under high diffusion of radiation the plants growing under the reed canopy gain approximately 38% radiation energy in comparison with periods characterised by low values of D*.
Rozproszone promieniowanie słoneczne powoduje wzrost produktywności ekosystemów. Jest to spowodowane między innymi tym, że ten rodzaj promieniowania lepiej penetruje roślinność, zmieniając tym samym warunki radiacyjne pod okapem roślin. Badanie przezroczystości trzcinowiska w różnych warunkach rozpraszania promieniowania pozwala na określenie warunków (ilości docierającej energii promienistej) bytowania roślin żyjących pod okapem trzcin. Prezentowane dane są wynikiem pomiarów wykonanych za pomocą sondy SS1 firmy Detla-T służącej do oceny warunków oraz parametrów radiacyjnych roślin. Badania przeprowadzono we wrześniu 2014 r. w łanie trzcin na torfowisku w Rzecinie (52°45′N, 16°18′E, 54 m n.p.m.). W wyniku przeprowadzonych analiz stwierdzono, iż przezroczystość trzcinowiska (Tr) jest wprost proporcjonalna do stopnia rozproszenia promieniowania docierającego do powierzchni roślin (D*), a jej wartość jest zawsze większa w warunkach D* = 1.0 od wartości Tr w okresach o małym rozpraszaniu promieniowania. Jednocześnie Tr jest odwrotnie proporcjonalne do wartości współczynnika ulistnienia (LAI). W warunkach pełnego rozproszenia ilość energii promienistej docierającej do roślin znajdujących się pod okapem trzcin wzrasta średnio o ok. 38% w porównaniu do okresów o niskich wartościach D*.
Źródło:
Acta Agrophysica; 2015, 22, 4
1234-4125
Pojawia się w:
Acta Agrophysica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3D Mapping by Photogrammetry and LiDAR in Forest Studies
Autorzy:
Firoz, Ahmad
Uddin, Md Meraj
Goparaju, Laxmi
Powiązania:
https://bibliotekanauki.pl/articles/1178078.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Anaglyph
Canopy Height Model
Lidar
Photogrammetry
Point cloud
Stereo-Image
Opis:
Aerial imagery have long been used for forest Inventories due to the high correlation between tree height and forest biophysical properties to determine the vertical canopy structure which is an important variable in forest inventories. The development in photogrammetric softwares and large availability of aerial imagery has carved the path in 3D mapping and has accelerated significantly the use of photogrammetry in forest inventory. There is tremendous capacity of 3D mapping which has been recognized in research, development and management of forest ecosystem. The aim of this article is to provide insights of 3D mapping (photogrammetry including Lidar) in forest-related disciplines. We utilizing the satellite stereo pair and LiDAR point cloud as a case study for producing the anaglyph map and Canopy Height Model (CHM) respectively. The study also revealed the area verses canopy height graph. Present study has some strength because it was demonstrated the use of advance software module of ARC/GIS and Erdas Imagine for 3D mapping using Photogrammetry and LiDAR data sets which is highly useful in forest management, planning and decision making.
Źródło:
World Scientific News; 2018, 95; 224-234
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza porównawcza cech konstrukcyjnych stropnic sekcji obudowy zmechanizowanej
Comparative analysis of design features of canopies of powered roof supports
Autorzy:
Bukowiecki, B.
Kościelny, A.
Mądry, M.
Powiązania:
https://bibliotekanauki.pl/articles/199520.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniki Górniczej KOMAG
Tematy:
sekcja obudowy zmechanizowanej
cechy konstrukcyjne stropnicy
obciążenia stropnicy
analiza porównawcza stropnic
powered roof supports
design features of canopy
loads to canopy
comparative analysis of canopies
Opis:
W artykule przedstawiono opis metodyki umożliwiającej przeprowadzenie analizy porównawczej stropnic sekcji obudowy zmechanizowanej. Zdefiniowano potrzebę jej wprowadzenia oraz przedstawiono zastosowanie procedury wyznaczania parametrów służących do oceny projektu postaci konstrukcyjnej stropnicy. Przedstawiono cztery zależności umożliwiające porównawczą ocenę postaci konstrukcyjnej stropnic. Dwie pierwsze przedstawiają wartość ekwiwalentnego momentu bezwładności w zależności od podporności stojaków i jednostkowej masy, natomiast w dwóch pozostałych przedstawiono wartości wskaźników kryterialnych. Spośród zaproponowanych postaci funkcji wybrano funkcję kryterialną charakteryzującą się największym współczynnikiem dopasowania liniowej funkcji trendu do wyników analizy porównawczej postaci konstrukcyjnej 34 stropnic.
Methodology enabling comparative analysis of canopies of powered roof supports is presented. The need of its implementation is specified and use of procedure for determination of parameters used for assessment of canopy design is explained. Four correlations enabling comparative assessment of design of canopies are presented. The first two relationships present the value of equivalent inertia in relation to load bearing capacity of the legs and unit weight, while the values of criterial indices are presented in the other two relationships. Criterial function of the highest matching coefficient of the linear trend function to the results of comparative analysis of design of 34 canopies was selected from the suggested forms of function.
Źródło:
Maszyny Górnicze; 2014, 32, 4; 15-21
0209-3693
2450-9442
Pojawia się w:
Maszyny Górnicze
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response of maize and black gram yield and water productivity to variations in canopy temperature and crop water stress index
Autorzy:
Khorsand, A.
Rezaverdinejad, V.
Asgarzadeh, H.
Heris, A.M.
Rahimi, A.
Besharat, S.
Powiązania:
https://bibliotekanauki.pl/articles/2082909.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
canopy temperature
crop yield
CWSI
phenolic
and flavonoid compounds
water stress
Opis:
In order to evaluate the ability of the crop water stress index to estimate grain yield and water productivity of maize and black gram in the climatic conditions of Urmia (Iran), research was conducted under the conditions of single-row drip irrigation. This study was conducted in a randomized complete block design with four irrigation levels including 50 (I1), 75 (I2), 100 (I3) and 125 (I4) percent of the water requirements of the plants with three replications. The mean crop water stress index values for the I1, I2 and I3 treatments were 0.53, 0.44, and 0.28, respectively during the growth period of maize, and 0.37, 0.23, and 0.15 for black gram, respectively. In the present study, the correlation between the crop water stress index and the grain yield and also the water productivity of maize and black gram was high. According to the results, the highest grain yield for maize and black gram was obtained at crop water stress index values of 0.28 and 0.15, respectively. Therefore, these values are recommended for the irrigation scheduling of the plants. It should be noted that the maximum water productivity index for maize and black gram was obtained at crop water stress index values of 0.44 (I2) and 0.37 (I1), respectively, which are the values recommended for irrigation scheduling under restricted access to water.
Źródło:
International Agrophysics; 2020, 34, 3; 381-390
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fatigue Degradation of the Ram-Air Parachute Canopy Structure
Autorzy:
Szafran, Krzysztof Stanisław
Kramarski, Ireneusz
Powiązania:
https://bibliotekanauki.pl/articles/98022.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
parachute systems
aerodynamic decelerator
ram-air canopy
fatigue degradation
aviation safety
Opis:
In this work, the authors continue researching issues related to fatigue of aircraft structures made of fabrics. Parachute systems are widely used in military, sport and recreational aviation. Braking parachutes as well as skydiving and troop parachutes are characterized by the repeated use of parachute canopies, which are exposed to wear and fatigue. Until now, parachutes were difficult to design aviation systems due to their complex and unsteady opening characteristics, large changes in the geometry of canopies, suspension lines and tape risers as well as exposure to stochastic atmospheric turbulence. The fatigue of the canopy fabric, suspension lines and tape risers is a problem that must be addressed by textile designers and designers of reusable parachute systems. The authors of this work demonstrate the complexity of operating a parachute in hard multiple use conditions and propose ways to extend the parachute’s service life without compromising safety.
Źródło:
Fatigue of Aircraft Structures; 2019, 11; 103-112
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study on color vegetation canopy images denoising algorithm
Autorzy:
Wang, C.
Liu, Y.
Wang, P.
Powiązania:
https://bibliotekanauki.pl/articles/199849.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
image denoising
color vegetation canopy images
adaptive mean filtering
color space
Opis:
Due to the characteristics of color vegetation canopy images which have multiple details and Gaussion noise interference, the adaptive mean filtering (AMF) algorithm is used to perform the denoising experiments on noised images in RGB and YUV color space. Based on the single color characteristics of color vegetation canopy images, a simplified AMF algorithm is proposed in this paper to shorten the overall running time of the denoising algorithm by simplifying the adaptive denoising processing of the component V, which contains less image details. Experimental results show that this method can effectively reduce the running time of the algorithm while maintaining a good denoising effect.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 3; 609-626
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Branching system of the Mexican hawthorn “Tejocote” (Crataegus spp.)
Autorzy:
Perez-Ortega, S.A.
Mendez-Santiago, A.H.
Nieto-Angel, R.
Jankiewicz, L.S.
Powiązania:
https://bibliotekanauki.pl/articles/2039.pdf
Data publikacji:
2013
Wydawca:
Instytut Ogrodnictwa
Tematy:
edible hawthorn
Mexican hawthorn
fruit tree
Crataegus
canopy architecture
branching system
inflorescence
morphological diversity
Źródło:
Journal of Horticultural Research; 2013, 21, 1
2300-5009
Pojawia się w:
Journal of Horticultural Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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