scholarly journals Reproductive success of the threatened Reed Parrotbill Paradoxornis heudei in non-harvested and harvested reedbeds in the Yangtze River estuary, China

2011 ◽  
Vol 22 (3) ◽  
pp. 339-347 ◽  
Author(s):  
ANTHONY BOULORD ◽  
ZHANG MEI ◽  
WANG TIAN-HOU ◽  
WANG XIAO-MING ◽  
FRÉDÉRIC JIGUET
Keyword(s):  
Breeding Season ◽  
River Estuary ◽  
Weather Conditions ◽  
Nesting Success ◽  
Conservation Strategies ◽  
Yangtze River Estuary ◽  
Nest Failure ◽  
Adverse Weather ◽  
Daily Nest Survival ◽  
The Impact

SummaryUnderstanding the factors that affect the nesting success of threatened birds is essential in designing effective conservation strategies. Here we compare nesting success of the Reed Parrotbill Paradoxornis heudei in annually harvested and non-harvested reedbed habitats in the Chongming Dongtan Nature Reserve in China, by recording the number of nestlings produced per nest and the causes of nest failure. We modelled daily nest survival rate (DSR) by considering the effects of harvesting, vegetation characteristics, year, date, advancement within the breeding season, nest age and nearest-nest distance, using the program MARK. Nest densities, but not the number of fledglings per nest, were significantly lower in harvested than non-harvested reedbed habitats. The best-fit DSR model estimated constant survival; none of the tested co-variables had significant effects. Moreover, harvesting did not affect the date of breeding initiation, likelihood of nest failure, or causes of nest failure, as vegetation cover was not significantly different between harvested and non-harvested reedbeds during the whole breeding season. Nest failure following adverse weather conditions was unusually common in harvested and non-harvested reedbeds, accounting for as many nest failures as depredation. However, comparisons with other studies suggest that deriving a conclusion on the impact of harvesting on nesting success is not straightforward and is probably linked to environmental characteristics affecting reed growth.

Modelling of 10 Gbps Free Space Optics Communication Link Using Array of Receivers in Moderate and Harsh Weather Conditions

2017 ◽  
Vol 38 (3) ◽  
Author(s):  
Amit Gupta ◽  
Nagpal Shaina
Keyword(s):  
Free Space ◽  
Weather Conditions ◽  
Quality Data ◽  
Laser Source ◽  
Communication Link ◽  
Free Space Optical ◽  
Space Optics ◽  
Received Power ◽  
Adverse Weather ◽  
The Impact

AbstractIntersymbol interference and attenuation of signal are two major parameters affecting the quality of transmission in Free Space Optical (FSO) Communication link. In this paper, the impact of these parameters on FSO communication link is analysed for delivering high-quality data transmission. The performance of the link is investigated under the influence of amplifier in the link. The performance parameters of the link like minimum bit error rate, received signal power and Quality factor are examined by employing erbium-doped fibre amplifier in the link. The effects of amplifier are visualized with the amount of received power. Further, the link is simulated for moderate weather conditions at various attenuation levels on transmitted signal. Finally, the designed link is analysed in adverse weather conditions by using high-power laser source for optimum performance.

Breeding ecology of the fairy martin

1999 ◽  
Vol 47 (5) ◽  
pp. 463 ◽  
Author(s):  
Michael J. L. Magrath
Keyword(s):  
Breeding Season ◽  
Weather Conditions ◽  
Adult Mortality ◽  
First Year ◽  
Breeding Ecology ◽  
Adult Males ◽  
Annual Productivity ◽  
Adverse Weather ◽  
Colony Site ◽  
The One

The breeding biology of the fairy martin, Hirundo ariel, was studied over three years (1992–95) in the Yarra Valley, Victoria. Adult males and females in this population were morphologically similar, though only females acquired a brood patch during the breeding season. Colonies ranged in size from 8 to 29 nests. Birds arrived in the study area in September and usually commenced laying in October, though nesting activities were generally asynchronous both between and within colonies. Most colonies contained active nests until February. At least 16% of adults and 5% of fledglings, on average, returned to the study area in the following year. Returning adults generally nested at the same colony site as the previous year, while most first-year birds nested at sites other than their natal colony. Adult males were more likely to return than adult females. Clutch size ranged from 2 to 5, with a mean of 3.5, and declined over the season. The incubation period varied from 12 to 18 days with a mean of 13.7. A mean of 1.8 chicks fledged per completed clutch, while 60% of clutches produced at least one chick. The period from hatching to fledging varied from 17 to 32 days, with a mean of 22.1, and increased with brood size. Fledging success was highest during the middle of the breeding season. Adverse weather conditions, resulting in the abandonment of clutch and brood, were the most common cause of nest failure, and on several occasions also resulted in adult mortality. Almost half the breeding females produced at least two clutches in the one season. Pairs produced from 0 to 8 fledglings per season, with those that commenced nesting earlier in the season having higher annual productivity. These results are discussed in relation to the breeding ecology of other members of the Hirundinidae.

Comparison of two gap-filling techniques for nitrous oxide fluxes from agricultural soil

2019 ◽  
Vol 99 (1) ◽  
pp. 12-24 ◽  
Author(s):  
Rezvan Taki ◽  
Claudia Wagner-Riddle ◽  
Gary Parkin ◽  
Rob Gordon ◽  
Andrew VanderZaag
Keyword(s):  
Missing Values ◽  
Interpolation Method ◽  
Weather Conditions ◽  
Linear Interpolation ◽  
Bias Error ◽  
Research Station ◽  
Ann Model ◽  
Gap Filling ◽  
Adverse Weather ◽  
The Impact

Micrometeorological methods are ideally suited for continuous measurements of N2O fluxes, but gaps in the time series occur due to low-turbulence conditions, power failures, and adverse weather conditions. Two gap-filling methods including linear interpolation and artificial neural networks (ANN) were utilized to reconstruct missing N2O flux data from a corn–soybean–wheat rotation and evaluate the impact on annual N2O emissions from 2001 to 2006 at the Elora Research Station, ON, Canada. The single-year ANN method is recommended because this method captured flux variability better than the linear interpolation method (average R2 of 0.41 vs. 0.34). Annual N2O emission and annual bias resulting from linear and single-year ANN were compatible with each other when there were few and short gaps (i.e., percentage of missing values <30%). However, with longer gaps (>20 d), the bias error in annual fluxes varied between 0.082 and 0.344 kg N2O-N ha−1 for linear and 0.069 and 0.109 kg N2O-N ha−1 for single-year ANN. Hence, the single-year ANN with lower annual bias and stable approach over various years is recommended, if the appropriate driving inputs (i.e., soil temperature, soil water content, precipitation, N mineral content, and snow depth) needed for the ANN model are available.

scholarly journals An Advanced Deep Learning Approach for Multi-Object Counting in Urban Vehicular Environments

2021 ◽  
Vol 13 (12) ◽  
pp. 306
Author(s):  
Ahmed Dirir ◽  
Henry Ignatious ◽  
Hesham Elsayed ◽  
Manzoor Khan ◽  
Mohammed Adib ◽  
...  
Keyword(s):  
Deep Learning ◽  
Intelligent Transportation Systems ◽  
Smart Cities ◽  
Weather Conditions ◽  
Research Area ◽  
Transportation Systems ◽  
Detection Accuracy ◽  
Adverse Weather ◽  
Object Counting ◽  
The Impact

Object counting is an active research area that gained more attention in the past few years. In smart cities, vehicle counting plays a crucial role in urban planning and management of the Intelligent Transportation Systems (ITS). Several approaches have been proposed in the literature to address this problem. However, the resulting detection accuracy is still not adequate. This paper proposes an efficient approach that uses deep learning concepts and correlation filters for multi-object counting and tracking. The performance of the proposed system is evaluated using a dataset consisting of 16 videos with different features to examine the impact of object density, image quality, angle of view, and speed of motion towards system accuracy. Performance evaluation exhibits promising results in normal traffic scenarios and adverse weather conditions. Moreover, the proposed approach outperforms the performance of two recent approaches from the literature.

scholarly journals Breeding Biology of Gray-Crowned Tyrannulet in the Monte Desert, Argentina

The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Eduardo T. Mezquida ◽  
Luis Marone
Keyword(s):  
Incubation Period ◽  
Breeding Season ◽  
Nesting Success ◽  
Nest Failure ◽  
East Central ◽  
Male And Female ◽  
Monte Desert ◽  
Present Information ◽  
Nestling Period ◽  
Wet Tropics

Abstract We present information from 75 nests of Gray-crowned Tyrannulet (Serpophaga griseiceps) found in open Prosopis woodlands of the central Monte desert between 1995 and 1997 and compare it with information corresponding to other species of the genus. Breeding occurred from October to January. Nests are small open cups. Both parents participated in nest building, which lasted 4–7 days. In the Prosopis woodland, 98% of the nests were built in chañar (Geoffroea decorticans), which also is commonly used as a nest plant by S. subcristata in east-central Argentina. Mean clutch size did not vary among years nor within the breeding season, and it was similar to that observed in other Serpophaga. Both male and female shared the 13–15 day incubation period. Hatching was asynchronous. Nestling period lasted 13–14 days, during which both parents reared the chicks. Nesting success (26%) appeared to be less than that previously reported for Nearctic open-nesters (50–60%), and Neotropical open-nesters in dry (50%) and wet tropics (35%). Egg and nestling predation were the main cause of nest failure.

Investigating the Impact of Rainfall on Travel Speed

2014 ◽  
Vol 71 (3) ◽  
Author(s):  
Nordiana Mashros ◽  
Johnnie Ben-Edigbe ◽  
Hashim Mohammed Alhassan ◽  
Sitti Asmah Hassan
Keyword(s):  
Empirical Studies ◽  
Heavy Rain ◽  
Weather Conditions ◽  
Travel Speed ◽  
Operating Conditions ◽  
Speed Reduction ◽  
Light Rain ◽  
Rainfall Condition ◽  
Adverse Weather ◽  
The Impact

The road network is particularly susceptible to adverse weather with a range of impacts when different weather conditions are experienced. Adverse weather often leads to decreases in traffic speed and subsequently affects the service levels. The paper is aimed at investigating the impact of rainfall on travel speed and quantifying the extent to which travel speed reduction occurs. Empirical studies were conducted on principle road in Terengganu and Johor, respectively for three months. Traffic data were collected by way of automatic traffic counter and rainfall data from the nearest raingauge station were supplied by the Department of Irrigation and Drainage supplemented by local survey data. These data were filtered to obtain traffic flow information for both dry and wet operating conditions and then were analyzed to see the effect of rainfall on percentile speeds. The results indicated that travel speed at 15th, 50th and 85th percentiles decrease with increasing rainfall intensities. It was observed that allpercentile speeds decreased from a minimum of 1% during light rain to a maximum of 14% during heavy rain. Based on the hypothesis that travel speed differ significantly between dry and rainfall condition; the study found substantial changes in percentile speeds and concluded that rainfalls irrespective of their intensities have significant impact on the travel speed.

Effectiveness of Predictive Weather-Related Active Transportation and Demand Management Strategies for Network Management

2017 ◽  
Vol 2667 (1) ◽  
pp. 71-87 ◽  
Author(s):  
Zihan Hong ◽  
Hani S. Mahmassani ◽  
Xiang Xu ◽  
Archak Mittal ◽  
Ying Chen ◽  
...  
Keyword(s):  
Traffic Management ◽  
Demand Management ◽  
Management Strategies ◽  
Weather Conditions ◽  
Active Transportation ◽  
Operational Conditions ◽  
Traffic Conditions ◽  
Adverse Weather ◽  
Traffic Performance ◽  
The Impact

This paper presents the development, implementation, and evaluation of predictive active transportation and demand management (ATDM) and weather-responsive traffic management (WRTM) strategies to support operations for weather-affected traffic conditions with traffic estimation and prediction system models. First, the problem is defined as a dynamic process of traffic system evolution under the impact of operational conditions and management strategies (interventions). A list of research questions to be addressed is provided. Second, a systematic framework for implementing and evaluating predictive weather-related ATDM strategies is illustrated. The framework consists of an offline model that simulates and evaluates the traffic operations and an online model that predicts traffic conditions and transits information to the offline model to generate or adjust traffic management strategies. Next, the detailed description and the logic design of ATDM and WRTM strategies to be evaluated are proposed. To determine effectiveness, the selection of strategy combination and sensitivity of operational features are assessed with a series of experiments implemented with a locally calibrated network in the Chicago, Illinois, area. The analysis results confirm the models’ ability to replicate observed traffic patterns and to evaluate the system performance across operational conditions. The results confirm the effectiveness of the predictive strategies tested in managing and improving traffic performance under adverse weather conditions. The results also verify that, with the appropriate operational settings and synergistic combination of strategies, weather-related ATDM strategies can generate maximal effectiveness to improve traffic performance.

scholarly journals Cardiovascular risk assessment of the population under adverse weather conditions

2020 ◽  
Vol 99 (5) ◽  
pp. 488-492
Author(s):  
R. B. Tsallagova ◽  
O. I. Kopytenkova ◽  
Fatima K. Makoeva ◽  
A. R. Nanieva
Keyword(s):  
Negative Impact ◽  
Adult Population ◽  
Medical Science ◽  
Weather Conditions ◽  
Air Pressure ◽  
Medical Documentation ◽  
Atmospheric Air ◽  
Adverse Weather ◽  
The Impact ◽  
The City

Introduction. Climate change around the world determines the relevance of the study of its effects on the human health. Nowadays, due to the development of modern medical science, the methods of evidence-based analysis of negative impact of the environmental factors on the public health are being widely implemented into preventive medicine. Their use should make it possible to quantify the various risks with high confidence and to manage them effectively. Material and methods. The weather conditions of the territory of Vladikavkaz for a 15-years period (2001-2015) have been studied. On the basis of the data from the primary medical documentation of emergency medical care (EMC) for the same period, the health status of the adult population in the city has been studied. The impact of the meteorological elements under the study on the frequency of seeking EMC was estimated using the relative (RR) and population risks (Rpop) values. Results. For the city of Vladikavkaz (according to the medical classification of weather conditions), high air humidity is typical for 65% of the days in a year, low air velocity (less than 3 m/s) - 77% of the days in a year. Inter-day fluctuations in temperature and atmospheric air pressure, exceeding the optimal levels for the human body, are recorded more than in 30% of the days in a year. Discussion. The city of Vladikavkaz is characterized by windless, wet weather, with frequent inter-day fluctuations in temperature and atmospheric air pressure, which corresponds to the clinically irritating and acute types of weather. Conclusion. The calculations of the relative and the population risks of impact of meteorological changes on the developing of urgent cardiovascular conditions in the population of Vladikavkaz showed RR of combining two unfavourable weather factors to be of 1.081 (p <0.0001), and the Rpop increases by more than 3600 additional EMC calls due to cardiovascular pathology.

scholarly journals MATHEMATICAL MODEL OF IMPLEMENTATION OF FIRE TASKS BY TANK CREW ON THE BATTLEFIELD

2020 ◽  
Vol 2 (36) ◽  
pp. 63-69
Author(s):  
D. Khaustov ◽  
◽  
Ya. Khaustov ◽  
V. Sokolovskij ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Markov Chain ◽  
Full Range ◽  
Weather Conditions ◽  
Observation System ◽  
Extended Model ◽  
Sequence Of Events ◽  
Functional Scheme ◽  
Adverse Weather ◽  
The Impact

Reconnaissance and defeat of enemy targets on the battlefield depends on the technical characteristics of surveillance and sighting devices, and it is important to ensure their effective operation, during both the day and night, especially in adverse weather conditions. Therefore, in the field of modernization and development of surveillance and sighting devices, by both domestic and foreign manufacturers, in recent years there has been a major trend towards the development of multi-channel sighting systems on armored vehicles. To determine the optimal parameters of the sighting systems of armored vehicle samples, it is necessary to develop a mathematical model that would take into account the entire process of target reconnaissance, including the impact of full range of natural and man-made obstacles, to determine the ways for the improvement of combat effectiveness of weapons samples. In this work, a mathematical model is developed for description of fire tasks execution on the battlefield by a tank crew, which is equipped with a multi-channel sight-monitoring system, to assess the work of the sighting system as whole as well as of each of its channels. The analysis of the functional scheme of solving the combat task shows that the stage of data acquisition should be divided into, at least three, separate states, namely: detection, recognition and identification such that the transitions between these states will be described by the corresponding probabilities. The developed model describes the sequence of events that in terms of probability theory form a Markov chain. The proposed analytical Markov model allows for modeling the solution of fire tasks by the tank crew equipped with a multi-channel sighting and observation system with separate consideration of the stages of target reconnaissance, its recognition and identification, which in turn are considered as separate states of the Markov chain. The model opens a possibility for the development of an extended model to determine a quantitative indicator to assess the effectiveness of a given sighting system in comparison with its analogs.

scholarly journals Influence of Overheating Phenomenon on Bitumen and Asphalt Mixture Properties

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 610 ◽  
Author(s):  
Michał Sarnowski ◽  
Karol Kowalski ◽  
Jan Król ◽  
Piotr Radziszewski
Keyword(s):  
Asphalt Mixture ◽  
Fatigue Cracking ◽  
Weather Conditions ◽  
Asphalt Mixtures ◽  
Heating Process ◽  
Test Results ◽  
Adverse Weather Conditions ◽  
Loss Of Resistance ◽  
Adverse Weather ◽  
The Impact

In the course of manufacturing, transport and installation, road bitumens and asphalt mixtures can be exposed to the impact of elevated process temperatures exceeding 240 °C. This mainly applies to the mixtures used for road pavements and bridge deck insulation during adverse weather conditions. The heating process should not change the basic and rheological properties of binders and the asphalt mixtures that to a degree cause the degradation of asphalt pavement durability. The work involved analyzing the properties of non-modified bitumens and SBS polymer modified bitumens, heated at temperatures of 200 °C, 250 °C and 300 °C for 1 h. Next, the asphalt mixtures were heated in the same temperatures. Based on the developed Overheating Degradation Index (ODI) it was demonstrated that polymer-modified bitumens were characterized by higher overheating sensitivity A(ODI) than non-modified bitumens, which was confirmed by mixture test results. Overheating limit temperatures T(ODI) were determined, which in the case of polymer-modified bitumens are up to 20 °C lower than for non-modified bitumens. When the temperature increases above T(ODI), loss of viscoelastic properties occurs in the material which causes, among other effects, a loss of resistance to fatigue cracking.

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