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Tytuł:
The Path-Distance-Width of Hypercubes
Autorzy:
Otachi, Yota
Powiązania:
https://bibliotekanauki.pl/articles/30146525.pdf
Data publikacji:
2013-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
path-distance-width
hypercube
Opis:
The path-distance-width of a connected graph G is the minimum integer w satisfying that there is a nonempty subset of S ⊆ V (G) such that the number of the vertices with distance i from S is at most w for any nonnegative integer i. In this note, we determine the path-distance-width of hypercubes.
Źródło:
Discussiones Mathematicae Graph Theory; 2013, 33, 2; 467-470
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the Reinforcing Bar Corrosion Level on the Flexural Crack’s Width in the Existing Structure
Autorzy:
Tur, Viktar V.
Yalavaya, Yuliya S.
Powiązania:
https://bibliotekanauki.pl/articles/132027.pdf
Data publikacji:
2019
Wydawca:
Centrum Rzeczoznawstwa Budowlanego Sp. z o.o.
Tematy:
existing structure
corrosion
crack width
Opis:
A study on the influence of the reinforcing bar corrosion level on the flexural crack’s width in the existing structure is presented. Parametric studies of the crack width development of corrosion damage were performed using a block model for the reinforced concrete element with corroded bars. The analytic description of the bond-slip law «t-s» and the establishment of the parametric points of this diagram are decisive in this model. Using the block model, the distribution of the concrete ε ct (x) and reinforcement εs(x) strains for the different level of corrosion damage, normal crack width was obtained and the effect of the level of corrosion damage was established.
Źródło:
Modern Engineering; 2019, 1; 1-9
2450-5501
Pojawia się w:
Modern Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of effective swath width for dual-head multibeam echosounder
Autorzy:
Grządziel, A.
Wąż, M.
Powiązania:
https://bibliotekanauki.pl/articles/320440.pdf
Data publikacji:
2016
Wydawca:
Polskie Forum Nawigacyjne
Tematy:
multibeam echosounder
survey
swath width
Opis:
Many surveying companies and maritime institutions are now using multibeam systems for their operations, either offshore or in coastal and inland waters. Since the time the first multibeam echosounder appeared (late 1970s) the technology has advanced enormously. Modern systems now boast far greater angular coverage (typically 120º–150º) and form hundreds of beams. Dual-head multibeam systems can potentially cover the entire sector (180º) underneath the ship. However surveyors must be aware that the outer beams of these acoustic systems return the most errors causing that the effective swath width is shorter than what the manufacturers declare. The paper presents the methods of estimating of effective (usable) swath width of dual-head multibeam echosounder EM 3002D. Results of the hydrographic survey performed by the polish navy survey ship ORP ‘Arctowski’ have been showed in the article.
Wiele biur hydrograficznych, firm komercyjnych zajmujących się pomiarami oraz instytu-cji i ośrodków szkoleniowych w swoich badaniach morskich i śródlądowych wykorzystuje akustyczne systemy wielowiązkowe. Od czasu pojawienia się pierwszej echosondy wielo-wiązkowej (lata 70. XX w.) technologia prac pomiarowych rozwinęła się na niespotykaną skalę. Nowoczesne systemy oferują dziś znacznie większe robocze kąty pracy przetwor-ników (zazwyczaj 120º–150º) i tworzą setki wiązek. Systemy dwugłowicowe mogą potencjalnie pracować w 180º kącie roboczym pod stępką jednostki. Hydrografowie muszą mieć jednak świadomość, że skrajne wiązki tych systemów generują największe błędy, powodując, że efektywna szerokość pasa pomiarowego danej sondy jest w istocie krótsza niż ta, jaką deklarują światowi producenci. W artykule przedstawiono metodę szacowania efektywnej (użytkowej) szerokości pasa pomiarowego dwuprzetwornikowej sondy EM 3002D. Zaprezentowano wyniki badań przeprowadzonych z pokładu okrętu hydrograficznego ORP ‘Arctowski’ na akwenie Bałtyku południowo-wschodniego.
Źródło:
Annual of Navigation; 2016, 23; 173-183
1640-8632
Pojawia się w:
Annual of Navigation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response surface methodology assisted multi-objectiveoptimization of TIG process for 15CDV6 steel
Autorzy:
Skariya, P. D.
Satheesh, D. M.
Dhas, J. E.
Chandrasekar, G.
Powiązania:
https://bibliotekanauki.pl/articles/1839113.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
TIG welding
15CDV6 HSLA steel
depth of penetration
bead width
HAZ width
Opis:
Welding is a way of heating pieces of metal usingelectricity or flame so that they melt and stick together. There aremany kinds of welding processes, such as, for instance, MIG/MAGand MMA welding. However, such welding schemes require moreelectrodes during the process of welding. Hence, this paper intendsto analyse the alternative tungsten inert gas (TIG) welding tech-nology using Response Surface Methodology (RSM), and to identifythe effect of TIG welding process parameters on the weld bead pro-file of 15CDV6 high strength low alloy (HSLA) steel. Moreover, themethodology applied allows for identification of the optimal weld-ing conditions by means of multi-objective optimization using RSMto increase the depth of penetration (DOP) and reduce BW (beadwidth) and heat-affected zone (HAZ) width. The variables takenfor the model-based investigations are: welding current (Wc), torchspeed (Ts), gas flow rate (Gr), torch angle (Ta) and arc gap (Ag).Moreover, the responses taken are DOP, BW and HAZ width. Fur-ther, the results from the proposed model optimisation can be seenas highly beneficial for the rocket-motor hardware program, indus-tries and fabrication of pressure vessels, which are using 15CDV6steel.
Źródło:
Control and Cybernetics; 2018, 47, 4; 465-496
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distribution of juniper stands and the impact of environmental parameters on growth in the drought-stressed forest-steppe zone of Central Anatolia
Autorzy:
Kahveci, G.
Alan, M.
Köse, N.
Powiązania:
https://bibliotekanauki.pl/articles/2077936.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Dendrochronology
dendroecology
tree-ring width
exposure
Opis:
Juniper is one of the three main tree species in Central Anatolia, where it grows under extreme environmental conditions. Although dendrochronological studies of juniper are challenging because of cross-dating problems, these types of studies on long-lived tree species have the potential to provide long time series, which reflect changes in climatic conditions. Juniper has been neglected as a scientific research subject in Turkey due to degraded populations and low economic expectations. This study analysed the distribution and present state of Juniperus spp. (Juniperus excelsa M. Bieb., Juniperus oxycedrus L., and Juniperus foetidissima Willd.) stands and used dendrochronological data to examine relationships between growth and environmental parameters. We hypothesised that there may be differences in the radial growth of juniper in areas of different exposure in drought regions. During a field survey, we sampled 31 plots of 25 m × 20 m and data, including information on wood cores, were collected. For dendrochronological investigation, 95 wood cores were manually measured and cross-dated. Residual chronologies of tree-ring width series of juniper from four wind directions and regional chronology of Kirikkale and Ankara Province were provided and similarities between the chronologies were tested using Gleichläufigkeits test. The relationships be- tween climate parameters and growth were examined using a simple correlation analysis and multiple lin- ear regression model analysis in SAS 9.0 program and response function analysis in the DENROCLIM2002 program. The results of this study indicated that Juniperus spp. in Central Anatolia are sensitive to envi- ronmental parameters and mainly respond to changes in precipitation. Juniper show differences in radial growth in areas of different exposure in drought regions. We conclude that juniper may offer an excellent opportunity for large-scale dendrochronological and dendroecological studies in drought regions.
Źródło:
Dendrobiology; 2018, 80; 61-69
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of the inverse base width modulation effect in HBT transistor with graded SiGe base
Autorzy:
Zaręba, A.
Łukasiak, L.
Jakubowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/308625.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
heterojunction bipolar transistor
SiGe
base width modulation
Opis:
A model of the position of the edge of emitter-base junction in the base and collector current pre-exponential ideality factor in HBT transistor with a SiGe base is presented. The model is valid for transistors with nonuniform profiles of doping and Ge content. The importance of taking into account the dependence of the effective density of states in SiGe on local Ge content and that of electron diffusion coefficient in SiGe on drift field for modeling accuracy is studied.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 3; 88-92
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of spiral vanes width on the separation performance of a hydrocyclone
Autorzy:
Liu, Peikun
Wang, Xiaoguo
Jiang, Lanyue
Zhang, Yuekan
Yang, Xinghua
Li, Xiaoyu
Wang, Hui
Powiązania:
https://bibliotekanauki.pl/articles/27323656.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hydrocyclone
vane width
numerical simulation
separation performance
Opis:
Aiming at the problem of “entrainment fine particles in underflow” of hydrocyclone in grinding and classification process, a hydrocyclone with spiral vanes (the SV hydrocyclone) was proposed. The CFD techniques were used to study the pressure field, velocity field, turbulence field, particle field and classification efficiency of hydrocyclones with spiral vanes of different widths. The results show that the pressure drop, axial velocity, tangential velocity, turbulence intensity of SV hydrocyclone are reduced in different degrees compared with conventional hydrocyclone, and the reduction becomes more obvious with the increase of vane width. In the case of a vane width of 0.04D, the underflow recovery rate of 5μm and 10μm fine particles was reduced by 16.2% and 15.7%. The selection of spiral vanes with small widths is beneficial to improve the separation accuracy of fine particles and reduce the cut particle size.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 6; art. no. 173563
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Realizacja operacji mnożenia o skróconej szerokości w układach FPGA
FPGA implementation of reduce-width multiplier
Autorzy:
Jamro, E.
Wielgosz, M.
Wiatr, K.
Powiązania:
https://bibliotekanauki.pl/articles/154019.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
układ mnożący
układy FPGA
FPGA
fixed-width multiplier
Opis:
Pełne mnożenie dwóch argumentów n-bitowych daje rezultat o szerokości 2xn-bitów. W większości przypadków stosuje się mnożenie o skróconej szerokości gdzie np. dodatkowe n najmłodszych bitów wyniku jest odrzucane. Niniejszy artykuł prezentuje nową metodę kompensacji błędu obliczeń dla mnożenia o skróconej szerokości szczególnie wydajną w przypadku użycia układów FPGA. Podstawą proponowanej architektury jest podawanie na niewykorzystywane do tej pory wejście przeniesienia wybranych bitów argumentów wejściowych układu mnożącego.
The paper presents a novel metod of the error compensation for a reduce-width multiplier implemented in FPGAs. For a standard multiplier and the bit-width equal to n for both inputs, the output width is equal to 2?n. In order to obtain a fixed-width multiplier, the n-LSBs of the output should be truncated. Lan-Da Van et. al. [1, 2] presented the error compensation method appropriate for ASIC, however, this method cannot be directly employed in FPGAs due to relatively high hardware resources and a different multiplier structure (compare Fig. 1 and Fig. 2). The main idea of the proposed error compensation method is to feed carry input directly with the selected bits of the multiplier input (see Fig. 4). The implementation results shown in Fig. 5 confirm the significant reduction of the truncation error, especially for the mean error which is close to zero. It should be noted that the error compensation circuit employs the normally unused carry-in input, therefore no additional FPGA resources are required by the proposed method.
Źródło:
Pomiary Automatyka Kontrola; 2009, R. 55, nr 8, 8; 669-671
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser frequency counting and frequency modulation width measurement from a FFT signal
Autorzy:
Křen, P.
Powiązania:
https://bibliotekanauki.pl/articles/221880.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser
modulation width
frequency measurement
optical frequency synthesizer
Opis:
A new method of optical frequency beat counting based on fast Fourier transform (FFT) analysis is described. Signals with a worse signal-to-noise ratio can be counted correctly comparing to the conventional counting method of detecting each period separately. The systematic error of FFT counting below 10 Hz is demonstrated and can be decreased. Additionally the modulation width of a frequency-stabilized laser with high frequency modulation index can be simultaneously measured during a carrier frequency measurement against an optical frequency synthesizer or other laser.
Źródło:
Metrology and Measurement Systems; 2012, 19, 3; 565-572
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badanie łączenia tarcicy na szerokość za pomocą kołków
Issledovanie po soedineniju piromateriala na shirinu s pomoshhju shipov
Investigitation on connection of sawnwood for width by means of pegs
Autorzy:
Graj, L.
Powiązania:
https://bibliotekanauki.pl/articles/808924.pdf
Data publikacji:
1990
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
badania
laczenie
tarcica
szerokosc
kolki
connection
timber
width
Opis:
В условиях повышенного спроса на древесину и постоянной тенденпии к переработке все более тонких сортиментов круглой древесины ледует считаться с трудностями в обеспечении соответствующих количеств пиломатериалов одинаковой крупной ширины. В связи с этим были проведены исследования по проверке и испольэванию технологических возможностей, которые бы позволили использовать в производстве пиломатериалы с шириной более узкой, чем ширина клееных элементов. Лабораторные опыты охватывали следующие этапы: а) изготовление из соснового пиломатериала толщиной 25 мм образпов размером 50 х 50 х 25 мм, б) выполнение соединения 2 образцов их боковыми поверхностями (поперек волокон) - с помощью склеивания, - с помощью желобчатых круглых широв размером 6 х 32, 8 х 36 и 10 х 40 мм.
At increased demand for wood and constant tendency to process thinner and thinner round wood assortments, it is to be reckoned with difficulties in getting a suitable sawnwood amount with equal great width. In this connection investigations on estimation and preparation of technological possibilities of using in production the sawnwood narrower than the width of glued elements have been undertaken. The laboratory tests comprised the following stages: a) making samples of 50 x 50 x 25 mm from 25 mm thick pine sawnwood, b) connection of 2 samples by their lateral areas (across fibres) by means of glueing, by round riffled pegs of 6 x 32, 8 x 36 and 10 x 40 mm, c) determination of forces in daN required for setting pegs in openings depeni ing on the fitting precision and needed for destruction of differently made joint by bending and tension of samples.
Źródło:
Zeszyty Problemowe Postępów Nauk Rolniczych; 1990, 379
0084-5477
Pojawia się w:
Zeszyty Problemowe Postępów Nauk Rolniczych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Algorithmic Aspects of Secure Connected Domination in Graphs
Autorzy:
Kumar, Jakkepalli Pavan
Reddy, P. Venkata Subba
Powiązania:
https://bibliotekanauki.pl/articles/32327157.pdf
Data publikacji:
2021-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
secure domination
complexity classes
tree-width
chordal graphs
Opis:
Let G = (V, E) be a simple, undirected and connected graph. A connected dominating set S ⊆ V is a secure connected dominating set of G, if for each u ∈ V \ S, there exists v ∈ S such that (u, v) ∈ E and the set (S \ {v}) ∪ {u} is a connected dominating set of G. The minimum size of a secure connected dominating set of G denoted by γsc(G), is called the secure connected domination number of G. Given a graph G and a positive integer k, the Secure Connected Domination (SCDM) problem is to check whether G has a secure connected dominating set of size at most k. In this paper, we prove that the SCDM problem is NP-complete for doubly chordal graphs, a subclass of chordal graphs. We investigate the complexity of this problem for some subclasses of bipartite graphs namely, star convex bipartite, comb convex bipartite, chordal bipartite and chain graphs. The Minimum Secure Connected Dominating Set (MSCDS) problem is to find a secure connected dominating set of minimum size in the input graph. We propose a (∆(G)+1)-approximation algorithm for MSCDS, where (G) is the maximum degree of the input graph G and prove that MSCDS cannot be approximated within (1 − ɛ) ln(|V|) for any ɛ > 0 unless NP ⊆ DTIME |V|O(log log |V|)) even for bipartite graphs. Finally, we show that the MSCDS is APX-complete for graphs with Δ(G) = 4.
Źródło:
Discussiones Mathematicae Graph Theory; 2021, 41, 4; 1179-1197
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of meteorological conditions in the growth of Robinia pseudoacacia on the basis of pointer years in urban conditions
Autorzy:
Kalbarczyk, Robert
Ziemiańska, Monika
Powiązania:
https://bibliotekanauki.pl/articles/957003.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
air temperature
rainfall
dendroclimatology
tree ring width
black locusts
Opis:
This study assessed changes in air temperature and rainfall during the growth of black locusts (Robinia pseudoacacia L.) in urban conditions in the city of Wroclaw based on pointer years. Materials consisted of 54 wooden discs taken from felled straight-trunked trees at a height of 1.3 m from the ground at four sampling sites in the area of a defunct garden established at the turn of the 20th century. Meteorological indicators were calculated based on monthly data obtained from the Wroclaw meteorological station, part of the national atmospheric monitoring network. Tree ring widths were determined using LINTABTM 6 and TSAP-Win software. A set of meteorological elements describing temperature and rainfall conditions during the growth of the black locusts significantly affecting the tree ring widths, were selected using cluster analysis. Pointer years were defined as the years when a unidirectional change (e.g. an increase) in tree ring width compared to a previous year was observed in at least 75% of the trees. In the multiannual period 1955–2014 we found seven pointer years, comprising three positive years (tree ring wider than in the year before): 1986, 1989, 1996, and four negative years (tree ring narrower than in the year before): 1963, 1983, 1990, 1991. The width of the tree rings were formed under the influence of different unique thermal and rainfall systems each year. Within the groups of positive and negative pointer years, individual months differed in the impact of air temperature and rainfall conditions on tree ring widths.
Źródło:
Dendrobiology; 2017, 77; 33-43
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wskaźnika zadrzewienia drzewostanu na wybrane cechy makrostruktury i gęstość drewna świerkowego (Picea abies (L.) Karst.)
Effect of stand density index on selected features of macrostructure and density of Norway spruce (Picea abies (L.) Karst.) wood
Autorzy:
Michalec, K.
Powiązania:
https://bibliotekanauki.pl/articles/978906.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
tree−ring width
latewood proportion
wood density
Norway spruce
Opis:
The aim of the study was to determine the influence of stand density index on the tree−ring width, latewood proportion and wood density for Norway spruce. Study sites were located as follows: 12 within the north−eastern species range in Poland, 7 in the south−western range, in the Sudety Mts., and 9 in the Carpathians (southern range). Clustering stands according to their stand density index, 10 data groups were established: stand density index values from 0.3 to 1.2. The study plots were 100×100 m squares. On each plot 15 trees were chosen and increment cores were sampled using the Pressler borer. The smoothed cores served for measuring the width of annual rings, latewood zones and the share of latewood as well as for determination of relative wood density. The performed analyses indicate that mean tree−ring width was the highest in trees from stands with density index from 0.3 to 0.8 (with the exception of 0.7), whereas the it was gradually decreasing in stands with index higher than 0.9. The statistically significant differences between the analyzed stands were observed (p<0.0001). The analysis of the influence of stand density index and the width of annual rings revealed significant, negative weak correlation (r=–0.242, p<0.001). In turn, the latewood proportion was the highest in trees from stands characterised by the highest stand density index and the lowest in trees from stands with the lowest one. The differences between analyzed groups of stands were statistically significant (p<0.0001), as well as the correlation which was significant, positive and weak (r=0.269, p<0.001). Wood density was the highest in trees from stands with the highest stand density index (1.1 – 363 kg/m3 i 1.2 – 365 kg/m3) as well as in those from stands characterised by 0.7 density index (369 kg/m3). Significant differences were observed (p<0.0001) only between stand density index 0.3−0.7 and 0.7−0.8. Significant correlation was not observed.
Źródło:
Sylwan; 2020, 164, 09; 719-725
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of vessel traffic flows on a waterway bend
Autorzy:
Przywarty, M.
Dzwonkowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/135120.pdf
Data publikacji:
2017
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
vessel traffic flows
traffic intensity
fairway width
fairway bend
Opis:
This paper presents preliminary results of research to develop a method of analysis of chosen parameters of vessel traffic flows on a bend in a waterway. Assumptions within the model are based on the geometrical dependences and, for a significant part, on expert experience and real life manoeuvring tactics. The work is focused on the analysis of coordinates of a ship, reduced to its centre of gravity, for different input and assumed output parameters. The proposed method allows also for the analysis of other parameters that influence navigational safety such as rate of turn. The results confirm the possibility of assessment of traffic flow parameters with use of the developed method. In the next stages of the work, algorithms which are capable of accounting for human factors and external conditions can be implemented.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2017, 50 (122); 68-74
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Way to reduce subgrade in highway construction
Autorzy:
Nemchinov, M. V.
Vasilyeva, A. G.
Powiązania:
https://bibliotekanauki.pl/articles/402409.pdf
Data publikacji:
2016
Wydawca:
Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:
subgrade
soil volumes
pipe
flow
width
depth
water discharge
Opis:
There is formulated the dement of minimum of land works in road construction. For it is suggested new method to construct road pipes and new method of their hydraulic design.
Źródło:
Structure and Environment; 2016, 8, 3; 147-152
2081-1500
Pojawia się w:
Structure and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydraulic parameters and morphometric variables interactions in bedrock channel
Autorzy:
Biswas, Biswajit
Chandra Das, Balai
Powiązania:
https://bibliotekanauki.pl/articles/1052833.pdf
Data publikacji:
2016-09-15
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
width/depth ratio
channel slope
hydraulic radius
velocity
stream power
Opis:
Present study is on the interdependent nature of hydraulic parameters and morphometric variables of a bedrock river. In this study, using dumpy level, GPS, satellite images and some mathematical equations a data set on hydraulics and morphometric variables of a bedrock channel, named Bhatajhor, of eastern India was generated. That data set was used to (1) find out impulse-response relations between hydraulic variables (2) find out relations between morphometric variables and (3) find out relations between hydraulic and morphometric variables. Seven equations (5–11) were formulated based on this empirical study to the end. The seven empirical relations, most of which include only two variables, involve channel cross-section dimensions (area, width, mean depth, maximum depth, width/depth ratio, hydraulic radius), slope and hydraulic variables (velocity, kinetic energy, stream power, Manning’s n factor, Chezy’s C factor and shear stress). Observation shows relatively higher coefficient of determination (R2) between variables like velocity and Manning’s n factor (0.67), velocity and Chezy’s C factor (0.67), slope and τ (0.89), w/d ratio and hydraulic radius (0.53), slope and w/d ratio (0.50).
Źródło:
Quaestiones Geographicae; 2016, 35, 3; 75-88
0137-477X
2081-6383
Pojawia się w:
Quaestiones Geographicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Climatic sensitivity of Quercus robur L. in floodplain near Kyiv under river regulation
Autorzy:
Netsvetov, Maksym
Prokopuk, Yulia
Didukh, Yakiv
Romenskyy, Maksym
Powiązania:
https://bibliotekanauki.pl/articles/956963.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
pedunculate oak
tree-ring width
riparian forest
dendroclimatology
moving correlation
Opis:
Climate change has a significant impact on natural ecosystems, particularly on floodplain forests that are among the most transformed ecosystems in the world. The climate sensitivity of dominant species is likely to play a key role in determining the susceptibility of flooded forests to climate changes. Here, we use dendrochronological approaches and local climate records from 1880 to 2015 to assess the response in pedunculate oak (Quercus robur L.) trees growing in a floodplain of the Dnipro River near Kyiv to climatic variables. Correlation analysis reveals the strongest positive association of the Q. robur tree-ring width chronology with May–June precipitation, May–June temperature, and May self-calibrating Palmers drought severity indices (scPDSI). The moving-window correlation analysis points to positive association with the scPDSI after the 1950s, when local river regulation was implemented. The positive correlation with current March precipitation is the least expected change in the oak growth-to-climate relationship that occurred in the aftermath of human alterations in the local river and regional climate changes. This study discusses the probable ecological consequences and ecophysiological mechanisms of observable climate-to-growth relationships and their temporal stability.
Źródło:
Dendrobiology; 2018, 79; 20-33
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser beam welding: research state of the art on performance and measures
Autorzy:
Chandran, Sudhin
Rajesh, R.
Devanand, M.
Powiązania:
https://bibliotekanauki.pl/articles/2049943.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
laser welding
beam width
heat treatment
performance measures
maximum performance
Opis:
Laser beam welding (LBW) is a remarkable method for combining dissimilar materials, primarily when the unique amalgamation of metals is necessary. LBW, owing to attractive features, namely: low heat input, high heat concentration, high power density and low distortion is one of the more advantageous methods for, e.g., welding and repair of aircraft and turbine engine elements, constructed from superalloy. In this paper, the literature is scrutinized on diverse techniques that are associated with laser welding systems. The review is provided of several dozen research articles, involving an appropriate analysis. Initially, the analysis depicts various schemes that are contributed in different articles. Subsequently, the analysis also focuses on various particular features such as laser beam width and type of laser, and it also considers the heat treatment analysis that is contained in each of the articles reviewed. Furthermore, the present paper provides a detailed study regarding the performance measures and maximum performance achievements regarding each contribution accounted for. Finally, it indicates the various research issues, which can be useful for the researchers to carry out further research on laser welding systems. Of particular interest to the Readers of this journal is the fact of ample application of modelling, identification, data processing, image processing and AI tools in the respective surveyed studies.
Źródło:
Control and Cybernetics; 2020, 49, 1; 123-153
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Existence and stabilizability of steady-state for semilinear pulse-width sampler controlled system
Autorzy:
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/255665.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
pulse-width sampler system
compact semigroup
steady-state
existence
stabilizability
Opis:
In this paper, we study the steady-state of a semilinear pulse-width sampler controlled system on infinite dimensional spaces. Firstly, by virtue of Schauder's fixed point theorem, the existence of periodic solutions is given. Secondly, utilizing a generalized Gronwall inequality given by us and the Banach fixed point theorem, the existence and stabilizability of a steady-state for the semilinear control system with pulse-width sampler is also obtained. At last, an example is given for demonstration.
Źródło:
Opuscula Mathematica; 2011, 31, 1; 105-118
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza rozwartości mikroszczelin w węglach
Estimation of the width of microfracture in coals
Autorzy:
Leśniak, G.
Powiązania:
https://bibliotekanauki.pl/articles/1835167.pdf
Data publikacji:
2018
Wydawca:
Instytut Nafty i Gazu - Państwowy Instytut Badawczy
Tematy:
przepuszczalność
mikroszczeliny
rozwartość
węgiel
permeability
microfracture
width of microfracture
coal
Opis:
Na podstawie wykonanych analiz mikroszczelinowatości, przepuszczalności i porowatości wykonano analizę rozwartości mikroszczelin przy określonym ciśnieniu nadkładu. Wyliczono porowatość szczelinową oraz porowatość matrycy. Przepuszczalność analizowanych próbek węgli określono jako szczelinową i wyznaczono trzy charakterystyczne przebiegi zamykania się szczelin pod wpływem ciśnienia nadkładu.
On the basis of performed analyzes of microfractures, permeabilities and porosities, the analysis of the microfracture width was done at a given overburden pressure. Fracture and matrix porosity were calculated. The permeability of the analyzed coal samples was determined as a fracture, and three characteristic courses of closing the fracture under the influence of overburden pressure were determined.
Źródło:
Nafta-Gaz; 2018, 74, 2; 79-84
0867-8871
Pojawia się w:
Nafta-Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of platelet indexes as potential biomarkers of suspected pulmonary embolism
Autorzy:
Wójcik, Mariusz
Daszyk-Wójcik, Joanna
Skoczyński, Kamil
Powiązania:
https://bibliotekanauki.pl/articles/454999.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
mean platelet volume
platelet count
platelet distribution width
pulmonary embolism
Opis:
Introduction. Pulmonary embolism is one of the most frequent cardiovascular diseases, potentially leading to death. There is no validated biomarker with both high specificity and sensitivity. Aim. The aim of the study was to define the diagnostic importance of platelet count (PLT), mean platelet volume (MPV) and platelet distribution width (PDW) on acute pulmonary embolism. Material and methods. We retrospectively reviewed the medical records of 145 patients with clinically suspected acute pulmonary embolism admitted to the Emergency Department. Demographic data and laboratory tests were collected on admission. All patients underwent computed tomography (CT) angiography. Results. The total data of 145 patients were analyzed, including 65 patients (67±17 years; 30 men/35 women) with acute pulmonary embolism confirmed with CT and 80 patients (67±19 years; 26 men/54 women) with negative CT. The MPV did not differ between the patients with acute PE and the control group (8.0 fL [IQR: 7.6-8.4] vs. 7.9 fL [IQR: 7.4-8.7], p=0.45). There were no significant differences in PLT (220x10³/mm³ [IQR: 172-274] vs. 243x10³/mm³ [IQR: 186-286], p=0.12) and PDW (59.0 ± 6.9% vs. 57.2 ± 7.3%, p=0.12). Conclusions. Our results suggest that platelet indexes (at a single time point) are not a reliable diagnostic biomarkers of acute pulmonary embolism.
Źródło:
European Journal of Clinical and Experimental Medicine; 2019, 2; 113-117
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The completely distributive lattice of machine invariant sets of infinite words
Autorzy:
Belovs, Aleksandrs
Buls, Jānis
Powiązania:
https://bibliotekanauki.pl/articles/728892.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
mealy machine
machine invariant class
completely distributive lattice
length
width
Opis:
We investigate the lattice of machine invariant classes. This is an infinite completely distributive lattice but it is not a Boolean lattice. The length and width of it is c. We show the subword complexity and the growth function create machine invariant classes.
Źródło:
Discussiones Mathematicae - General Algebra and Applications; 2007, 27, 1; 109-121
1509-9415
Pojawia się w:
Discussiones Mathematicae - General Algebra and Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Difference Effect of Mouth Width Size and Operating Depth of Sodo (Push net) on the Catch of Rebon Shrimp (Acetes indicus H. Milne Edwards, 1830) in Tanah Kuning Waters, North Kalimantan, Indonesia
Autorzy:
Rahmayani, Rahmayani
Hamdani, Herman
Junianto, Junianto
Izza, A. Mahdiana
Powiązania:
https://bibliotekanauki.pl/articles/1062751.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Acetes indicus
Rebon shrimp
Sodo mouth width size
depth
sodo
Opis:
Sodo (push net) is a fishing gear used to capture Rebon shrimp (Acetes indicus H. Milne-Edwards, 1830) by fishermen in Tanah Kuning water and it has a construction for varied operation depth. The purpose of this study was to determine the combination of the size of the mouth width and depth of operation of Sodo to get the most Rebon shrimp catch in the waters of Tanah Kuning. The study method used is experimental with Randomized Block Design (RBD). The first group is the size of the width used, equaling 4.8 m, 6 m, and 7.2 m, and depths of 0.5 to 3 m, and 4 to 6 m. The catch data was taken on January 15-22 2019. The results show that the A2B1 treatment, which is a combination of the size of the mouth width of 6 m and operated at a depth 0.5 – 3 m, was the best treatment, with the highest catch of mass 238 kg.
Źródło:
World Scientific News; 2019, 133; 121-131
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Method for assessment of changes in the width of cracks in cement composites with use of computer image processing and analysis
Autorzy:
Tomczak, K.
Jakubowski, J.
Fiołek, P.
Powiązania:
https://bibliotekanauki.pl/articles/178219.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cracks in concrete
crack width measurement
image processing
self-healing
Opis:
Crack width measurement is an important element of research on the progress of self-healing cement composites. Due to the nature of this research, the method of measuring the width of cracks and their changes over time must meet specific requirements. The article presents a novel method of measuring crack width based on images from a scanner with an optical resolution of 6400 dpi, subject to initial image processing in the ImageJ development environment and further processing and analysis of results. After registering a series of images of the cracks at different times using SIFT conversion (Scale-Invariant Feature Transform), a dense network of line segments is created in all images, intersecting the cracks perpendicular to the local axes. Along these line segments, brightness profiles are extracted, which are the basis for determination of crack width. The distribution and rotation of the line of intersection in a regular layout, automation of transformations, management of images and profiles of brightness, and data analysis to determine the width of cracks and their changes over time are made automatically by own code in the ImageJ and VBA environment. The article describes the method, tests on its properties, sources of measurement uncertainty. It also presents an example of application of the method in research on autogenous self-healing of concrete, specifically the ability to reduce a sample crack width and its full closure within 28 days of the self-healing process.
Źródło:
Studia Geotechnica et Mechanica; 2017, 39, 2; 73-80
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiana z wiekiem przyrostu grubości dębu na stosunkowych wysokościach
Changes in ring width increment of oak at relative heights over time
Autorzy:
Turski, M.
Powiązania:
https://bibliotekanauki.pl/articles/973587.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
dendrometria
przyrost grubosci
Quercus
przyrost grubości
leśnictwo
dąb
rozkład przyrostu grubości
drzewa leśne
oak
ring width increment at relative heights
ring width increment variation
Opis:
The paper presents the distribution and variation in radial increment at relative heights of 28 oaks from an 80 year−old oak stand during 5 successive periods of tree lives. Besides the amplitude of relative radial increment at relative heights in 5−year incremental periods was also analysed. The change in relative radial increment at relative heights of oak stems complies with literature data found for other species.
Źródło:
Sylwan; 2004, 143, 08; 8-15
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł

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