scholarly journals Factors affecting the response of Seychelles Scops-owl Otus insularis to playback of conspecific calls: consequences for monitoring and management

2002 ◽  
Vol 12 (4) ◽  
pp. 353-364 ◽  
Author(s):  
David Currie ◽  
James Millett ◽  
Mike Hill ◽  
Nirmal Jivan Shah
Keyword(s):  
Fixed Points ◽  
Response Times ◽  
Probability Of Detection ◽  
Territory Size ◽  
Detection Rates ◽  
Factors Affecting ◽  
Significant Seasonal Variation ◽  
Repeated Use ◽  
Low Probability ◽  
Current Monitoring

The endemic Seychelles Scops-owl Otus insularis is a Critically Endangered restricted range species currently only recorded in the upland forest of Mahé, the largest (152 km2) and highest (903 m) island in the granitic Seychelles. We studied the response of colour-ringed individuals to playback of conspecific calls, to determine factors affecting playback reaction, to monitor behaviour and to assess the reliability of current monitoring techniques. Playback of the territorial waugh call was conducted at fixed points (c. 200 m apart) every month along a total transect length of 8.4 km between April 1999 and May 2001. On the basis of responses and movements of marked individuals we identified 12 territories and noted their boundaries. Mean territory length was 2.92 points (approximately 400 m), equivalent to a conservative estimated territory size of c. 12–16 ha. Males were more frequently detected than females/pairs. The probability of detection (males vs. females/pairs) was 0.87 vs. 0.50 on territory; 0.65 vs. 0.26 at fixed points within territories; and 0.58 vs. 0.22 at fixed points along the transect. There was some significant seasonal variation in detection rates at fixed points within territories for both males and pairs, and in general there was a low probability of detecting individuals around June-August and a high probability of detection around April and, to a lesser degree, October. Response times and owl-recorder distances were not influenced by moon phase or time of playback. This study provides the first baseline data on individual responses to the systematic repeated use of playback in Seychelles Scops-owl. We discuss the implications for current monitoring and its application to other similar Otus species.

scholarly journals Analysis of Low Probability of Detection Capability for Chaotic Standard Map-Based FH-OFDMA System

2021 ◽  
Vol 11 (5) ◽  
pp. 2198
Author(s):  
Junwoo Jung ◽  
Jaesung Lim ◽  
Sungyeol Park ◽  
Haengik Kang ◽  
Seungbok Kwon
Keyword(s):  
Detection Probability ◽  
Probability Of Detection ◽  
Lower Probability ◽  
Symbol Sequence ◽  
Ofdma System ◽  
Standard Map ◽  
Detection Probabilities ◽  
Low Probability ◽  
Transmitted Symbol ◽  
Basic Symbol

A frequency hopping orthogonal frequency division multiple access (FH-OFDMA) can provide low probability of detection (LPD) and anti-jamming capabilities to users against adversary detectors. To obtain an extreme LPD capability that cannot be provided by the basic symbol-by-symbol (SBS)-based FH pattern, we proposed two FH patterns, namely chaotic standard map (CSM) and cat map for FH-OFDMA systems. In our previous work, through analysis of complexity to regenerate the transmitted symbol sequence, at the point of adversary detectors, we found that the CSM had a lower probability of intercept than the cat map and SBS. It is possible when a detector already knows symbol and frame structures, and the detector has been synchronized to the FH-OFDMA system. Unlike the previous work, here, we analyze whether the CSM provides greater LPD capability than the cat map and SBS by detection probability using spectrum sensing technique. We analyze the detection probability of the CSM and provide detection probabilities of the cat map and SBS compared to the CSM. Based on our analysis of the detection probability and numerical results, it is evident that the CSM provides greater LPD capability than both the cat map and SBS-based FH-OFDMA systems.

scholarly journals Assessing the Risk to Indoor Thermal Environments on Industrial Sites Offering AHU Capacity for Demand Response

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6261
Author(s):  
Alexander Brem ◽  
Ken Bruton ◽  
Paul D. O’Sullivan
Keyword(s):  
Demand Response ◽  
Response Times ◽  
Industrial Sector ◽  
Industrial Building ◽  
Factors Affecting ◽  
Ambient Temperatures ◽  
Thermal Environments ◽  
Industrial Sites ◽  
Electricity Grids

Increasing participation in demand response within the industrial sector may be crucial to growing the levels of available flexible capacity required to reliably control national electricity grids as renewable generation increases to satisfy emission targets. This research aims to assist the uptake of demand response in the industrial sector by investigating risk to indoor thermal environments on industrial sites offering air handling unit capacity for demand response. This evaluation uses a systematic model-based approach, calibrated and validated with empirical data from a relevant case study industrial building to assess risk through a number of scenarios. The conditions investigated cover several relevant grid response times and durations, and national and international extreme external ambient temperatures in the past, present and future under a variety of temperature limits. The study demonstrated that there is very low risk to the case study site participating in demand response, with only 15 of 264 initial and 284 of 936 total scenarios triggering any risk. The major factors affecting risk levels identified were more stringent temperature limits and the influence of more extreme climates. The development and implementation of this concept has considerable potential to benefit industrial participants and the wider national electricity grids.

Factors Affecting Aerial Surveys of Marine Fauna, and Their Relationship to a Census of Dugongs in the Coastal Waters of the Northern-Territory

1986 ◽  
Vol 13 (1) ◽  
pp. 27 ◽  
Author(s):  
P Bayliss
Keyword(s):  
Coastal Waters ◽  
Total Population ◽  
Surface Condition ◽  
High Tide ◽  
Northern Territory ◽  
Probability Of Detection ◽  
Correction Factors ◽  
Marine Fauna ◽  
Factors Affecting ◽  
Similar Range

Some factors that may affect the aerial counts of dugongs, dolphins and turtles were examined experimentally. Tidal influence did not affect the counts of dugongs or dolphins, but those of turtles increased around high tide. A combined doubling of survey altitude and transect width reduced observed density of all three classes of animals by 50%. The counts of four observers did not differ significantly, but further data counsel caution. Overcast weather depressed counts of dugongs and turtles. Dolphin counts were affected by water surface condition, counts being lowest in choppy seas. A mark-recapture model was used on tandem observations to derive correction factors for groups of animals missed on the surface of a transect. Observers missed between 33% and 75% of dugong groups on the surface, the probability of detection decreasing with increased survey altitude and transect width. A similar range and pattern of probabilities was found for dolphins and turtles. Dugongs were censused in the coastal waters of the Northern Territory between the Daly River and Millingimbi in December 1983, an area of 28 746 km*2. Sampling intensity was 7.6%. A minimum population of 2953 � 530 (standard error) was estimated, an overall relative density of 0.11 � 0.02 km-2. A theoretical correction for submerged dugongs not seen yielded a total population estimate of 38 000, an overall density of 1.46 km-2. The distribution of dugongs in the survey area was patchy, the highest densities being associated with shallow coastal waters, sheltered bays, and large islands.

Factors affecting the detection of possums by spotlighting in Western Australia

2005 ◽  
Vol 32 (8) ◽  
pp. 689 ◽  
Author(s):  
A. F. Wayne ◽  
A. Cowling ◽  
J. F. Rooney ◽  
C. G. Ward ◽  
I. B. Wheeler ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Lunar Cycle ◽  
Survey Method ◽  
Brushtail Possum ◽  
Start Time ◽  
Detection Rates ◽  
Eucalyptus Marginata ◽  
Factors Affecting ◽  
Abundance Estimates ◽  
Time Required

This paper describes how environmental factors, survey method procedures and differences in forest structure resulting from logging relate to the detection of koomal (common brushtail possum, Trichosurus vulpecula hypoleucus) and ngwayir (western ringtail possum, Pseudocheirus occidentalis). A total of 169 vehicle-based spotlight surveys of possums within native jarrah (Eucalyptus marginata) forest was conducted on three transects over eight years (1996–2003). Up to 5.7 koomal and up to 3.3 ngwayir were detected per kilometre per transect side. Only one ngwayir was detected during the eight surveys conducted between 2001 and 2003. More koomal were seen in spring and autumn (i.e. September–November and March–May respectively) and more ngwayir were seen between October and April. Although surveys were not conducted on very rainy or excessively windy nights, fewer possums were nonetheless seen on nights following rainy days and on cold nights. Cloud cover also affected sightings of koomal. The time taken to complete the surveys increased in conjunction with the number of possums detected, on account of the time required to record data. The importance of standardising travelling speed also is emphasised. Possum spotlight counts differed between recently logged and unlogged areas. However, these findings were not supported by complementary koomal abundance estimates derived from trapping, suggesting that vegetation structure may affect detectability. Factors such as the lunar cycle, wind speed and survey start time after sunset did not significantly affect detection rates of either species. On the basis of these findings, specific survey conditions can be selected to improve spotlight detection efficiency.

scholarly journals Low Probability of Detection Communication: Opportunities and Challenges

2019 ◽  
Vol 26 (5) ◽  
pp. 19-25 ◽  
Author(s):  
Shihao Yan ◽  
Xiangyun Zhou ◽  
Jinsong Hu ◽  
Stephen V. Hanly
Keyword(s):  
Probability Of Detection ◽  
Low Probability

Very low probability of detection of TiH2 molecule in a cosmic object

New Astronomy ◽  
2016 ◽  
Vol 48 ◽  
pp. 1-4 ◽  
Author(s):  
M.K. Sharma ◽  
M. Sharma ◽  
S. Chandra
Keyword(s):  
Probability Of Detection ◽  
Low Probability ◽  
Cosmic Object

scholarly journals Management Options and Factors Affecting Control of a Common Waterhemp (Amaranthus rudis) Biotype Resistant to Protoporphyrinogen Oxidase-Inhibiting Herbicides

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Dana B. Harder ◽  
Kelly A. Nelson ◽  
Reid J. Smeda
Keyword(s):  
Herbicide Resistance ◽  
Herbicide Application ◽  
Management Options ◽  
Protoporphyrinogen Oxidase ◽  
Factors Affecting ◽  
Common Waterhemp ◽  
Control Options ◽  
Amaranthus Rudis ◽  
Repeated Use ◽  
Herbicide Activity

Repeated use of protox-inhibiting herbicides has resulted in a common waterhemp (Amaranthus rudisSauer) biotype that survived lactofen applied up to 10 times the labeled rate. Field and greenhouse research evaluated control options for this biotype of common waterhemp. In the field, PRE applications of flumioxazin at 72 g ai ha−1, sulfentrazone at 240 g ai ha−1, and isoxaflutole at 70 g ai ha−1controlled common waterhemp >90% up to 6 weeks after treatment. POST applications of fomesafen at 330 g ai ha−1, lactofen at 220 g ai ha−1, and acifluorfen at 420 g ai ha−1resulted in <60% visual control of common waterhemp, but differences were detected among herbicides. In the greenhouse, glyphosate was the only herbicide that controlled protox resistant waterhemp. The majority of herbicide activity from POST flumioxazin, fomesafen, acifluorfen, and lactofen was from foliar placement, but control was less than 40% regardless of placement. Control of common waterhemp seeded at weekly intervals after herbicide treatment with flumioxazin, fomesafen, sulfentrazone, atrazine, and isoxaflutole exceeded 85% at 0 weeks after herbicide application (WAHA), while control with isoxaflutole was greater than 60% 6 WAHA. PRE and POST options for protox-resistant common waterhemp are available to manage herbicide resistance.

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