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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Effects of Predatory Cues on Copper Sensitivity and Metabolic Rate in Gambusia affinis

Campbell, Melissa N 01 May 2017 (has links)
Organisms living in aquatic environments are subject to a number of stressors from natural (temperature, predation, food availability) and anthropogenic origins (pesticides, metals, etc). Natural stressors may amplify the effects of contaminants and increase an organism’s sensitivity to them. Understanding the impact of these combined factors is therefore essential for the practical management of contaminants. This study sought to examine how predatory cues affect copper tolerance in the mosquitofish, Gambusia affinis. The influence of predatory cues on fish metabolic rate was also evaluated to gain insight on any interactive effects between the natural stressor and copper. Alarm cues, chemicals released into the water when prey are injured were obtained from humanely sacrificed G. affinis, and kairomones, passive cues released by predators, were obtained from adult bluegill (Lepomis macrochirus). Paired 96-h toxicity tests with copper and predatory cue and with copper alone were conducted to determine the influence of predatory cues on G. affinis sensitivity to the metal. In the presence of alarm cue neither G. affinis copper tolerance or metabolic rate was altered. At copper concentrations ranging from 0.25mg Cu/L - 0.50mg Cu/L kairomone presence had no influence on survival, while between 0.50mg Cu/L and 1.0mg Cu/L, kairomone presence increased survival. Kairomone had no significant effect on metabolic rate. The apparent antagonistic effect between kairomone and copper may have resulted from the presence of organic material from predator-derived cues or from potential changes in fish behavior. This study adds to the growing body of literature which illustrates the complexity of stressor interactions in aquatic systems.
42

An Experimental Analysis of the Alarm Calls of Captive Uinta Ground Squirrels (Spermophilus armatus)

Cherry, Marion Barch 01 May 1979 (has links)
This study investigated alarm calls given by Uinta ground squirrels (Spermophilus armatus) in the presence of a ground predator. I observed predator responses of 18 groups of three to four squirrels each for an average of three trials apiece. r~y objectives were: (1) to describe prey-predator interactions resulting in alarm calls, and (2) to test the following hypotheses: 1. Each Uinta ground squirrel (by sex and age) has an equal probability of giving an alarm call at any time of the season. 2. All Uinta ground squirrels are equally likely to call regardless of their distance to a burrow, closest conspecific, and the predator. 3. Alarm calls are as likely to occur in the search stage of predation as in the pursuit stage. 4. Callers and noncallers are equally vulnerable to predation. I found that: ( 1) each Uinta ground squirrel (by sex and age) in the experimental population had an equal probability of giving an alarm call in the presence of a predator through the season, (2) callers and noncallers were equally close to burrows at the time of the call, (3) the caller was typically located farther away from its closest conspecific than noncallers at the time of the cal l, (4) the caller was significantly closer to the predator than were noncallers at the time of the call, (5) alarm calls occurred significantly more often in the pursuit stage of predation than in the search stage, and (6) noncallers suffered significantly more predation than did callers. There appeared to be little risk and energetic cost associated with calling. Squirrels that called usually were being pursued by the predator and were very close to a burrow when they called. The callers had little to lose and could increase their inclusive fitness by warning relatives of the presence of danger. This study dealt only with responses to ground predators. Squirrels are likely to respond differently to avian predators. It is suggested that responses of animals to avian and terrestrial predators should vary with the potential threat that the predator poses. The apparent inhibition of secondary calls is discussed. Once animals are aware of the presence of danger, there is no need for another animal to repeat the message and reveal its location to the predator.
43

Analysis and Recognition of Flames from Different Fuels

Guo, Shangyuan, Wang, Dailu January 2010 (has links)
<p>This paper presents a method for recognition of flame types coming from different kinds of fuel through analysis of flame images. Accurate detection of fire alarm and achievement of early warning is positive development for cities fire safety. Image-based fire flame detection technology is a new effective way to achieve early warning through the early fire flame detection. Different fuel combustion in air it the basic of basis to recognize the type of flame. The application built up by using generic color model and the techniques of image analysis.</p>
44

Alarm Calling in the Context of Flying Predator Stimuli: A Field Study of Carolina Chickadees (Poecile carolinensis)

Zachau, Christopher Erik 01 May 2011 (has links)
This study describes chick-a-dee calling behavior of Carolina chickadees (Poecile carolinensis) in the presence of “flying” predator models. Previous experimental research with black-capped chickadees (Poecile atricapilla) as well as Mexican chickadees (Poecile sclateri) suggested a relationship between the presence of predator stimuli and the note composition of chick-a-dee calls. Carolina chickadees were presented with two types of stimuli in field settings. These models were painted to resemble either a predatory sharp-shinned hawk (Accipiter striatus) or a blue jay (Cyanocitta cristata). Models consisted of pairs of five varying shapes, making ten models in all. A randomly chosen model was covered with a cloth and attached to a zip-line fastened to a tree about five meters high. During the procedure the cloth was removed and the model was released, causing it to “fly” to the opposite end of the zip line, which was attached at ground level. These trials were audio recorded at 20 field sites in eastern Tennessee from January - March 2010 and January - February 2011. Chickadees produced more C notes in response to hawk models than to blue jay models. Additionally, chickadees produced more A and C notes as well as more total notes during the post-exposure period than during the pre-exposure period for both the hawk and the blue jay conditions. The chickadees’ increased production of C notes in response to the hawk stimuli is consistent with previous research conducted on Mexican chickadees, potentially suggesting that the call structure of Carolina chickadees in threatening predator contexts is more similar to that of Mexican, rather than black-capped chickadees. Finally, chickadees increased production of A notes and C notes to the presence of both model types, providing support for the “Better Safe Than Sorry” strategy.
45

Bridge Navigational Watch Alarm System : Styrmäns uppfattning om att arbeta med systemet

Stark, Krister, Widebeck, Tim January 2013 (has links)
År 2009 antog IMO en ny resolution som innebär att ett nytt instrument gradvis kommer införas som obligatorisk standardutrustning på fartygsbryggan. Detta system förkortas BNWAS vilket står för Bridge Navigational Watch Alarm System och är kortfattat ett dödmansalarm som syftar till att varna vid otillräcklig aktivitet på bryggan. Detta system har funnits en tid men blir nu obligatoriskt ombord. Detta påverkar arbetssituationen och arbetsmiljön för vakthavande styrmän. Denna studie syftar till att undersöka vad styrmän som arbetar med systemet har för uppfattning och åsikter om systemet. Hur upplever de att det påverkar deras arbete under vakten? Tror de att systemet kommer att hjälpa till att höja säkerheten till sjöss? För att besvara dessa frågor har en intervjustudie genomförts med sex vakthavande styrmän som aktivt arbetar till sjöss. Detta har lett till ett varierat resultat där det bland annat visat sig att styrmännen som intervjuats är generellt positiva till systemet men med vissa reservationer. Några fördelar de ser är att BNWAS är ett effektivt sätt att påkalla hjälp ifall vakthavande styrman blir utslagen av medicinska skäl, sömnbrist eller liknande. Systemet minskar risken för att bryggan lämnas obemannad men inger ingen trygghet hos styrmännen angående mötande fartyg. En del styrmän har en farhåga om att BNWAS kommer användas som en lösning på trötthet och därmed leda till att styrmän pressas hårdare. Något som också kommit fram är att styrmän anser att ett system som är utformat enbart enligt IMOs grundkrav kan vara störande, distraherande och irriterande. Men det finns tillägg till systemen som innebär betydligt mindre inverkan i styrmännens arbete. / In 2009, IMO adopted a new resolution to gradually introduce a new instrument as mandatory standard equipment on the bridge. This system is called BNWAS (Bridge Navigational Watch Alarm System) and is a dead man’s watch designed to warn if insufficient activity is detected on the bridge. This system has been in use for some time but will now be mandatory on board. This affects working conditions for duty officers. This study aims to investigate the officer’s opinions about the system and what they think of working with BNWAS. Do they think that the system will affect their work during the watch? And if, in what way? Do they think that the system will help to improve safety at sea? To answer these questions six interviews were conducted with six active duty officers. This has led to diverse results were in general the officers interviewed were positive to the system but with certain reservations. Some advantages they see are that BNWAS is an effective way to draw attention to the need for help if the OOW is out of action due to medical reasons, lack of sleep or similar circumstances. The system reduces the risk of the bridge being left unattended but provides no sense of security for officers regarding oncoming traffic as there is still no guarantee that the bridge on these vessels is attended. Some officers have a fear that BNWAS will be used as a solution to fatigue and thus lead to the officers being pushed harder. Something else that was revealed during this study is that when the system is installed according to IMO's minimum requirements the officers find it disturbing, distracting and irritating. But it is possible to have additional equipment installed to the system to minimize the distraction.
46

SMS-baserat alarm med positionering : GPS based alarm with positioning

Nors, Niclas, Rehnström, Tom January 2008 (has links)
The study investigates how to design a low-cost, versatile event messaging system using SMS. A typical use case is a fire alarm or intrusion detector when equipped with appropriate sensors. With a GPS receiver connected, the actual position is included in the message, allowing for use as theft alarm in e.g. a car or in mobile home. / Studien undersöker hur man kan konstruera ett billigt, mångsidigt meddelandesystem som använder SMS. Ett exempel på användningsområde är brandlarm eller inbrottslarm med motsvarande sensorer anslutna. Även positionen kan förmedlas med en GPS ansluten, och då finns även möjligheten att använda enheten som stöldlarm för till exempel bil eller husvagn.
47

Development of Ocean Net Cage Acoustic Alarm System

Hung, Shih-wei 13 July 2004 (has links)
In recent years, the fishery production has been drastically decreased in Taiwan, mainly due to overfishing and coast pollutions, therefore fishermen and corporation are encouraged by government to invest in ocean cage aquaculture. However the high price fishes in the net cage are often coveted, so the incidences of fish stealing and net cage breaking were found occasionally, which cause great economical loss. Security guards or visual monitoring system has limited effect especially in the night when these intrusions occur. This study is based on acoustic measure to build a net cage alarm system, which includes the sonobuoy and monitor station on land. The sonobuoy is a passive sonar that collects the sounds near the net cage and transmits the suspected signal to the monitor station. The signals were analyzed by the control program on the personal computer in the monitor station, and the alarms at different stages could be activated by the sound levels and durations of the analyzed signals.
48

SMS-baserat alarm med positionering : GPS based alarm with positioning

Nors, Niclas, Rehnström, Tom January 2008 (has links)
<p>The study investigates how to design a low-cost, versatile event messaging system using SMS. A typical use case is a fire alarm or intrusion detector when equipped with appropriate sensors. With a GPS receiver connected, the actual position is included in the message, allowing for use as theft alarm in e.g. a car or in mobile home.</p> / <p>Studien undersöker hur man kan konstruera ett billigt, mångsidigt meddelandesystem som använder SMS. Ett exempel på användningsområde är brandlarm eller inbrottslarm med motsvarande sensorer anslutna. Även positionen kan förmedlas med en GPS ansluten, och då finns även möjligheten att använda enheten som stöldlarm för till exempel bil eller husvagn.</p>
49

THE EFFECT OF HABITAT SOUND PROPERTIES ON ALARM CALLING BEHAVIOR IN TWO SPECIES OF TREE SQUIRRELS (SCIURUS NAYARITENSIS AND SCIURUS ARIZONENSIS)

Hobbs, Donna Edeen January 1980 (has links)
Sound attenuation properties of the habitats occupied by two species of tree squirrels affect whether or not the squirrels will make alarm calls. Sound properties have been compared among habitats, microhabitats, weather conditions and seasons. In each case alarm calling activity is consistent with the hypothesis that calling behavior is acted upon by natural selection: calling occurs when squirrel calls carry well, and thus where the potential for communication is high.
50

Intelligent Economic Alarm Processor (IEAP)

Guan, Yufan 16 December 2013 (has links)
The advent of electricity market deregulation has placed great emphasis on the availability of information, the analysis of this information, and the subsequent decision-making to optimize system operation in a competitive environment. This creates a need for better ways of correlating the market activity with the physical grid operating states in real time and sharing such information among market participants. Choices of command and control actions may result in different financial consequences for market participants and severely impact their profits. This work provides a solution, the Intelligent Economic Alarm Processor to be implemented in a control center to assist the grid operator in rapidly identifying the faulted sections and market operation management. The task of fault section estimation is difficult when multiple faults, failures of protection devices, and false data are involved. A Fuzzy Reasoning Petri-nets approach has been proposed to tackle the complexities. In this approach, the fuzzy reasoning starting from protection system status data and ending with estimation of faulted power system section is formulated by Petri-nets. The reasoning process is implemented by matrix operations. Next, in order to better feed the FRPN model with more accurate inputs, the failure rates of the protections devices are analyzed. A new approach to assess the circuit breaker’s life cycle or deterioration stages using its control circuit data is introduced. Unlike the traditional “mean time” criteria, the deterioration stages have been mathematically defined by setting up the limits of various performance indices. The model can be automatically updated as the new real-time condition-based data become available to assess the CB’s operation performance using probability distributions. The economic alarm processor module is discussed in the end. This processor firstly analyzes the fault severity based on the information retrieved from the fault section estimation module, and gives the changes in the LMPs, total generation cost, congestion revenue etc. with electricity market schedules and trends. Then some suggested restorative actions are given to optimize the overall system benefit. When market participants receive such information in advance, they make estimation about the system operator's restorative action and their competitors' reaction to it.

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