scholarly journals Quantifying the relationships between network distance and straight-line distance: applications in spatial bias correction

Annals of GIS ◽  
2021 ◽  
pp. 1-19
Author(s):  
Xinyue Chen ◽  
Yimin Chen
Keyword(s):  
Bias Correction ◽  
Spatial Bias ◽  
Network Distance ◽  
Straight Line ◽  
Straight Line Distance

scholarly journals Locomotion postural variability and coordination in boys with overweight

2021 ◽  
pp. 105971232110240
Author(s):  
Shahab Parvinpour ◽  
Marzie Balali ◽  
Mohsen Shafizadeh ◽  
Fatemeh Samimi Pazhuh ◽  
Michael Duncan ◽  
...  
Keyword(s):  
Body Mass ◽  
Movement Pattern ◽  
Approximate Entropy ◽  
Normal Weight ◽  
Multiscale Entropy ◽  
Body Movements ◽  
Straight Line ◽  
Straight Line Distance

The purpose of this study was to examine the variability and coordination of postural adaptations in normal weight children and those with overweight in running and hopping. Fifty-six boys between 7 and 10 years were classified into groups as overweight ( n = 33) or normal-weight ( n = 23). They performed two trials of running and hopping over a 20-m straight line distance. Accelerometers were attached on the trunk and head for collecting body movements in different directions from 15 strides. Postural variability and coordination were calculated by multiscale entropy and cross approximate entropy for the running and hopping trials, separately. Findings highlight overweight boys had significantly higher trunk-head coordination in mediolateral direction than normal-weight boys (0.72 vs. 0.68). The hopping movement pattern had highest variability (9.88 vs. 8.77) and trunk–head coordination (0.61 vs. 0.67) than running. Excess body mass demands additional postural adaptations to compensate for reducing the risk of losing balance laterally in boys with overweight.

Dispersal patterns in a regional koala population in south-east Queensland

2003 ◽  
Vol 30 (3) ◽  
pp. 281 ◽  
Author(s):  
David S. Dique ◽  
Jim Thompson ◽  
Harriet J. Preece ◽  
Deidré L. de Villiers ◽  
Frank N. Carrick
Keyword(s):  
Urban Areas ◽  
Home Ranges ◽  
Adult Males ◽  
Dispersal Patterns ◽  
Young Males ◽  
Straight Line ◽  
The Social ◽  
Straight Line Distance ◽  
Males And Females ◽  
Natal Home

Koala dispersal was investigated as part of a detailed ecological study of a nationally significant koala population located 20 km south-east of Brisbane, Queensland. From 1996 to 2000, 195 koalas from three sites were captured and fitted with radio-collars. A total of 40 koalas (23 males and 17 females) dispersed from these sites. Most (93%) dispersing individuals were 20–36 months of age. Three adult females (more than 36 months old) dispersed and no adult males dispersed during the study. A significantly higher proportion of young males dispersed than females. Dispersal occurred between June and December, with most dispersal of males commencing in July and August and that of females commencing between September and November prior to, and early in, the annual breeding season. The mean straight-line distance between the natal and breeding home ranges for males and females was similar and was measured at 3.5 km (range 1.1–9.7 km) and 3.4 km (range 0.3–10.6 km) respectively. Dispersing males and females tended to successfully disperse south and west of their natal home ranges and were generally unable to successfully disperse to urban areas within the study area, as a high proportion of the mortality of dispersing koalas was associated with attacks by domestic dogs and with collisions with vehicles on roads. Information from other studies indicates that most young koalas disperse from their natal areas. It is likely that the social behaviour and mating systems of koala populations provide mechanisms for young koalas to disperse. The potential role of dispersal in the dynamics of regional koala populations is discussed.

scholarly journals Dispersal of Potato Cyst Nematodes Measured Using Historical and Spatial Statistical Analyses

2012 ◽  
Vol 102 (6) ◽  
pp. 620-626 ◽  
Author(s):  
N. C. Banks ◽  
M. Hodda ◽  
S. K. Singh ◽  
E. M. Matveeva
Keyword(s):  
Control Strategies ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Detection Distance ◽  
Rate Of Spread ◽  
Linear Distance ◽  
Straight Line ◽  
Constant Rate ◽  
Straight Line Distance ◽  
Road Distance

Rates and modes of dispersal of potato cyst nematodes (PCNs) were investigated. Analysis of records from eight countries suggested that PCNs spread a mean distance of 5.3 km/year radially from the site of first detection, and spread 212 km over ≈40 years before detection. Data from four countries with more detailed histories of invasion were analyzed further, using distance from first detection, distance from previous detection, distance from nearest detection, straight line distance, and road distance. Linear distance from first detection was significantly related to the time since the first detection. Estimated rate of spread was 5.7 km/year, and did not differ statistically between countries. Time between the first detection and estimated introduction date varied between 0 and 20 years, and differed among countries. Road distances from nearest and first detection were statistically significantly related to time, and gave slightly higher estimates for rate of spread of 6.0 and 7.9 km/year, respectively. These results indicate that the original site of introduction of PCNs may act as a source for subsequent spread and that this may occur at a relatively constant rate over time regardless of whether this distance is measured by road or by a straight line. The implications of this constant radial rate of dispersal for biosecurity and pest management are discussed, along with the effects of control strategies.

scholarly journals 2D Photogrammetry as a Forwarder Load Measurement Technique

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 962
Author(s):  
Ondřej Nuhlíček ◽  
Martin Slavík ◽  
Jiří Dvořák
Keyword(s):  
Laser Scanning ◽  
P Value ◽  
Large Area ◽  
Load Measurement ◽  
Vertical Distance ◽  
Straight Line ◽  
Significant Difference ◽  
Straight Line Distance ◽  
Load Height ◽  
Measured Distance

Research Highlights: In this study, we present the use of time-lapse photos as a way to estimate the height of the load on the forwarders. This approach, using nonprofessional outdoor cameras, is a cheap and time-effective solution for continuous load height measurements, and it offers at least the same accuracy as a gauge measurement. This method represents another approach to the automation of time studies in forestry. Background and Objectives: Time studies require information about the load on the forwarders. Until now, this information was obtained either by using a gauge measure, sampling of the load, or averaging the load from large area datasets. More accurate methods like laser scanning are costly and fragile. During time study preparations, we suggested a robust system of measuring the load height and tested it against the commonly used gauge measuring technique. Materials and Methods: Two cameras took pictures of the load; these photos were processed for camera lens distortion and rectified into the cartesian coordinate system, and the height of the load was calculated. These values were then tested against gauge measured values using paired t-test. Results: Straight line distance calculated from the images and the gauge-measured distance did not show a significant difference (p-value 0.9354). Calculated vertical distance was, however, significantly different from the calculated straight-line distance (p-value of 0.0015), suggesting possible bias of the gauge measured distance. The root mean square error (RMSE) of the rectification process was, on average, 0.42 cm. Conclusions: The proposed method was verified to correspond with the gauge measure method; however, our research raised the question of the gauge method reliability, as the taken measurements are not perfectly vertical, and for the correct load estimation, the vertical distance is needed. We, therefore, conclude that for this photogrammetry method, the vertical, rather than straight-line, distance should be used. The presented solution can be used for long-term data collection without interrupting the whole forwarding process for taking the load measurement. The longer data processing in office enables researchers to spend less time in the field taking hand measurements.

scholarly journals Reptilia, Squamata, Viperidae, Bothrops venezuelensis Leybold, 1873: Distribution extension and first country record

Check List ◽  
2012 ◽  
Vol 8 (2) ◽  
pp. 310
Author(s):  
Juan Salvador Mendoza ◽  
Viviana Berrio ◽  
Diego A. Gómez
Keyword(s):  
Species Distribution ◽  
Important Species ◽  
Straight Line ◽  
Straight Line Distance

We report on the presence of Bothrops venezuelensis Leybold, 1873 in Norte de Santander and Boyacá departments, Colombia. These findings represent the first records for the country. Extending the species’ distribution 474 km in a straight-line distance SW from its nearest previously known Venezuelan locality. The present record adds a new clinically important species for Colombia, which needs to be considered in the production of anti-ophidic serum.

At-sea behavior of juvenile male northern fur seals (Callorhinus ursinus)

2004 ◽  
Vol 82 (10) ◽  
pp. 1621-1637 ◽  
Author(s):  
J T Sterling ◽  
R R Ream
Keyword(s):  
Body Mass ◽  
Mass Gain ◽  
Callorhinus Ursinus ◽  
Juvenile Male ◽  
Deep Waters ◽  
Fur Seals ◽  
Straight Line ◽  
Northern Fur Seals ◽  
Straight Line Distance ◽  
Pribilof Islands

The at-sea behavior of juvenile male northern fur seals, Callorhinus ursinus (L., 1758), captured at two haul-out sites on St. Paul Island, Alaska, during the 1999 and 2000 breeding seasons (July–September) was studied. To compare at-sea locations, dive behavior, and changes in body mass, 31 juveniles between the estimated ages of 3–6 years were captured, instrumented, and released. Individuals behaved like central-place foragers by making trips to sea and returning to the Pribilof Islands. Trip durations ranged between 8.74 and 29.81 d, whereas distances from departure site ranged between 171.27 and 680.68 km (maximum straight-line distance). Differences in maximum straight-line distance traveled and trip duration were not observed when comparing years or departure site. Diving tended to reflect patterns associated with different bathymetric domains; shallow nighttime diving was common in ~3000 m deep waters, whereas deeper diving was generally observed in <200 m deep waters. Proportion of body mass gained over a single trip to sea averaged 27.8% (range 3%–65%, n = 19). Mass gain was similar between individuals that dove in shallow waters (over the continental shelf; 10.9 ± 1.8 kg (mean ± 1 SE), n = 11) versus individuals that dove in pelagic waters (8.5 ± 1.0 kg, n = 8). These results demonstrate that the at-sea behavior of juvenile males can extend farther from the Pribilof Islands when compared with previous reports of parturient female at-sea behavior, thus revealing important variation within this species.

Tsunami and Seismic Damage Caused by the Earthquake Off Iquique, Chile, in April, 2014

2016 ◽  
Vol 10 (02) ◽  
pp. 1640003 ◽  
Author(s):  
Takashi Tomita ◽  
Kentaro Kumagai ◽  
Cyril Mokrani ◽  
Rodrigo Cienfuegos ◽  
Hisashi Matsui
Keyword(s):  
Seismic Damage ◽  
South American ◽  
Nazca Plate ◽  
South American Plate ◽  
Straight Line ◽  
Earthquake Resistant ◽  
Straight Line Distance ◽  
Run Up ◽  
Tsunami Run Up ◽  
The City

On Tuesday, April 1, 2014, at 8:46 p.m. local time in Chile, a subduction earthquake of Mw 8.2 occurred about 100[Formula: see text]km northwest of the city of Iquique, where the Nazca plate subducts beneath the South American plate. This earthquake triggered a tsunami, which hit coastal areas in northern Chile. A joint Japan–Chile team conducted a post-tsunami field survey to measure the height of the tsunami traces and to investigate the damage caused by the earthquake and tsunami. Based on measurements of the tsunami traces, it is estimated that a tsunami 3–4[Formula: see text]m in height hit the coast from Arica, which is near the border between Chile and Peru, to Patache, south of Iquique, a straight-line distance of approximately 260[Formula: see text]km. The tsunami caused only minor inundations near shorelines, and caused no damage to buildings because living spaces were higher than the tsunami run-up height. Seismic damage was more extensive than that caused by the tsunami, especially in Iquique, and included the destruction of houses, buildings, and other infrastructure. It also ignited fires. In the Port of Iquique, a wharf, before earthquake-resistant improvements were implemented, was destroyed by the strong ground motions that resulted from the earthquake.

Genetic structure and dispersal of red foxes (Vulpes vulpes) in urban Melbourne

2001 ◽  
Vol 49 (6) ◽  
pp. 589 ◽  
Author(s):  
Nicholas A. Robinson ◽  
Clive A. Marks
Keyword(s):  
Vulpes Vulpes ◽  
Dispersal Distance ◽  
Regression Equations ◽  
Ecological Data ◽  
Red Foxes ◽  
Island Populations ◽  
Straight Line ◽  
Straight Line Distance ◽  
Dispersal Distances ◽  
Group Density

This study sought to investigate the potential for gene flow and dispersal between three sampled populations of urban Melbourne foxes (Vulpes vulpes). Five highly polymorphic canine microsatellites were used to investigate the population structure of foxes. The dispersal of 14 foxes, captured and radio-collared as cubs, were monitored periodically over two years. Dispersal estimates for males and females were also calculated from published regression equations that related social group density to dispersal distance. Genetic differentiation between urban populations was greater than between more widely spaced rural populations and was also greater than that found between San Remo and Phillip Island populations, which are separated by a water barrier. A deficiency of heterozygotes was detected in the total Melbourne population, but not at any of the field sites. Mean dispersal distances after 24 months (male = 3.5 km, female = 2.0 km) compared well with published accounts of dispersal in British cities. Dispersal distance estimates for female foxes from all sites were lower than straight-line distance for all but one site. Both the genetic and ecological data suggest a restricted ability for foxes to disperse between sites within urban Melbourne.

Sign in / Sign up

Export Citation Format

Share Document