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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.
31

Market response time as a new approach for more effective marketing planning in business-to-business sales

Gorne, J., Grohmann, A. January 2010 (has links)
Published Article / The ability to increase turnover in a short time is determined by industry characteristics. These characteristics need to be taken into account during forecasting and planning. The correlation. which can be described among others by the Market Response Time (MRT) has an impact upon the whole marketing planning. MRT is defined as the time between increased marketing efforts (stimuli) and the time when the market starts to react in terms of increased purchasing (response). It is expected that different industries have different MRTs which influence the analyzed planning in different ways. Thus sales planning must be adapted to MRT, which will most probably increase planning efficiency.
32

System Analysis for Hydrostatic Transmission for Wave Energy Applications - Simulation and Validation

Dießel, Dominic, Bryans, Garth, Verdegem, Louis, Murrenhoff, Hubertus 03 May 2016 (has links) (PDF)
Wave Energy Converters (WEC) are used to transform energy stored in ocean waves into electrical energy. One type of WECs consists of buoyant bodies. To extract energy from their motion, hydraulic cylinders can be used to generate hydraulic power. For conversion into electric power various systems have been analysed in literature. However, the focus was put on efficiency and rigorous analyses of the system behaviour are still missing. In this paper an exemplary system consisting of two hydraulic cylinders, switchable check valves, accumulators and three motor-generator sets is analysed with help of simulation and measurement. This exemplary system is called WavePOD and was installed at the Institute for Fluid Power Drives and Controls (IFAS) of RWTH Aachen University together with Aquamarine Power and Bosch Rexroth for testing. In this paper the data collected during various test phases is used for system analysis and for validating the simulation. The simulation model is presented. The system’s response to various switching operations is investigated. Comparing the simulation with measurements validates the system`s dynamic model.
33

Search engines and how we evaluate them : - A comparison between the search engines Elasticsearch and EPiServer Find

Nilsson, Kim, Larsson, Anton January 2017 (has links)
Sigma IT Consulting in Växjö gave the authors of this paper a task to change the search engine in one of their projects. To get a scientific view of the project the authors specified two research questions that could be connected to Sigma's problem. This problem is interesting to investigate since search engines are frequently used all over the world and often more user-friendly than classic menu navigation. To find a solution to the problem two experiments were conducted. The result from the experiments showed that the search engine EPiServer Find were, ever so slightly, outperformed Elasticsearch in the terms of relevance. The response time, however, had no significant difference.
34

Dynamique d'émission de champ photo-assistée à partir de nanofils de silicium individuels / Dynamic of photo-assisted field emission from individual silicon nanowires

Derouet, Arnaud 23 June 2014 (has links)
La recherche sur les sources d'électrons modulées en temps connaît actuellement un vif intérêt, notamment dans le domaine des sciences fondamentales ou pour certaines applications exigeantes. C'est dans ce contexte que ce travail exploratoire sur l'émission de champ (EC) photo-assistée de nanofils de silicium s'inscrit. Nous explorons dans un premier temps les caractéristiques émissives de ces nanofils semi-conducteurs présentant un régime de saturation très prononcé, très sensible à la température et à la lumière, et encore jamais observé pour de telles structures à température ambiante. Le rôle important joué par la surface dans la saturation est prouvé par des traitements in-situ ayant des conséquences radicales sur les caractéristiques courant-tension de l'EC. Grâce à des cycles de passivation à l'hydrogène nous avons pu montrer le rôle des liaisons pendantes à l'interface matériau/oxyde dans la saturation et basculer de façon réversible entre un comportement quasi-métallique et semiconducteur. Nous étudions ensuite la réponse de ces émetteurs à une excitation optique modulée en temps. Leur réponse est attribuée à la photoconduction due à l'absorption directe : les effets thermiques peuvent être exclus à ces puissances laser. Nous avons alors mis en évidence la présence de deux constantes de temps associées à l'éclairement et la relaxation de l'échantillon. Le rôle des états pièges en surface prend là encore une part importante dans le temps de réponse de l'échantillon en limitant celui-ci à quelques dizaines de microsecondes seulement. Enfin nous avons mis en évidence un effet complètement nouveau en EC sous éclairage laser : une double résistance différentielle négative. Dans les dispositifs à semiconducteurs, cet effet est généralement associé à des oscillations de courant à haute fréquence et ouvre la perspective vers des sources EC compactes et auto-oscillantes à très hautes fréquences / There is currently a notable rise in research on time modulated electron sources for new fundamental science and for several demanding applications. Our exploratory work on photo-assisted field emission (FE) from silicon nanowires falls within this context. We first explore FE characteristics of these semiconducting nanowires, which are very sensitive to temperature and light and present a very pronounced current saturation regime, never observed before on such structures. The strong influence of surface states on the saturation regime is proven by in-situ treatments, which radically alter the FE current-voltage characteristics. H-passivation cycles reveal the role of dangling bonds at material/oxide interface in the saturation regime and allow to reversibly switch between a quasi-metal and semiconductor behavior. We then study the response of these emitters to a time modulated optical excitation. The response is attributed to direct absorption photoconduction after excluding thermal effects at these laser powers. The existence of two time constants associated with illumination and relaxation time is shown. The role of the surface state traps again plays an important part in the response time, limiting it to some tens of microseconds. Finally, a completely new effect in FE under laser illumination is identified : a double negative differential resistance. In semiconductor devices this effect is usually associated with high frequency current oscillations and thus opens perspectives toward compact and high frequency self-oscillating FE sources
35

Evaluating the Necessity of Third-Party Antivirus Software

Baker, Erik January 2018 (has links)
Some may assume that it is essential to purchase and install antivirus software to protect the underlying layers of an IT infrastructure. However, nowadays the Windows 10 operating system is shipped with a built-in antivirus feature by default. With Microsoft being a large contender in the antivirus market it raises the question if it is necessary to use third-party antivirus software in a Windows 10 environment.   The aim of this research is to determine the necessity of third-party antivirus software by examining the detection capabilities and measuring the performance impact caused by third-party antivirus software, in comparison with the antivirus service that is integrated with the Windows 10 operating system. This was done by measuring the response time of certain user activities to determine how the user-experience is affected differently by using third-party antivirus software. In addition to the effect on performance, the documentation of the tested products was studied to determine if there is value in using non-integrated antivirus software.   The results of the performance benchmarks showed that overall there was a significant performance increase when using third-party antivirus. Additionally, the study showed that some third-party antivirus software offers more ways to detect malicious activities than Windows Defender Antivirus. These two facts put together suggests that using third-party antivirus software in a Windows 10 environment is necessary if there is a desire to increase the efficiency of performing certain user activities and if there is a desire to have more detection capabilities available.
36

On the impact and applicability of network edge computing to reduce network latencies of worldwide client applications

Horsthemke, Stephan January 2020 (has links)
This project evaluates the applicability of network edge computing to reduce global latencies of client applications. It determines the dimension of latency reduction network edge computing can provide compared to common cloud computing architectures. Furthermore, this project examines whether Compute@Edge, an exemplary and modern edge computing service, enables the replacement of many latency-sensitive cloud systems by an adequate versatility and a reasonable costbenefit ratio. Compute@Edge is a new, serverless edge computing platform by Fastly built on WebAssembly. A prototype that replicates a globally utilized server of Spotify was implemented on Compute@Edge. To compare the latencies of cloud and edge computing, an experiment captured the latencies of the prototype and the original system using a Spotify client that generated almost 26 million data points from all over the world. Next to the experiment, the implementation of the prototype allows accurate insights into the possibilities of Compute@Edge and whether WebAssembly is a promising approach for edge computing. Successes of this work include data showing that network edge computing can reduce latencies significantly. It offers arguments to ramp up the usage of edge computing, WebAssembly and Compute@Edge for applications that require low latencies. The results of the experiment show that network edge computing is capable of reducing network latency compared to cloud computing by at least 38%. The lower latencies combined with the versatility and feasibility of Compute@Edge show that modern edge platforms enable a much higher utilization for applications like Spotify. / Projektet utvärderar hur applicerbart nätverks edge computing är för att minska global latens av kundapplikationer. Den avgör att dimensionen av fördröjnings minskningen i nätverks edge computing kan ge i jämförelse till vanliga cloud computing arkitekturer. Projektet undersöker också om Compute@Edge, en exemplarisk och modernt edge computing service, möjliggör ett byte av många latens-känsliga cloud system och då med en lämplig användbarhet och ett rimlig kostnads-nyttoförhållande. Compute@Edge är en ny serverlös edge computing platform av Fastly, byggt på WebAssembly. En prototype som replikerar en globalt använd server av Spotify var implementerad på Compute@Edge. För att jämföra latenserna av cloud och edge computing, genomfördes ett experiment som fångade upp latenserna av prototypen och det ursprungliga systemet med hjälp från en Spotify kund som genererade runt 26 millioner globala datapunkter. Med experimentet, ger prototypimplementeringen exakta insikter till möjligheterna med Compute@Edge och om WebAssembly är en lovande lösning till edge computing. Arbetes framgång inkluderar data som visar att nätverks edge computing kan minska latensen betydligt. Det visar också argument för att öka på användingen av edge computing, WebAssembly och Compute@Edge till applikationer som behöver låga latens. Experimentets resultat visar att nätverks edge computing kan minska nätverkslatens i jämförelse till cloud computing med åtminstone 38%. De lägre latenserna kombinerade med användbarheten och möjligheten av Compute@Edge visar att moderna edge plattformar ger möjligheter till mycket mer bättre översättning för applikationer som Spotify.
37

Vocal response times to acoustic stimuli in white whales and bottlenose dolphins

Blackwood, Diane Joyner 30 September 2004 (has links)
Response times have been used to explore cognitive and perceptual processes since 1850 (Donders, 1868). The technique has primarily been applied to humans, birds, and terrestrial mammals. Results from two studies are presented here that examine response times in bottlenose dolphins (Tursiops truncatus) and white whales (Delphinapterus leucas). One study concerned response times to stimuli well above the threshold of perceptibility of a stimulus, and the other concerned response times to stimuli near threshold. Two white whales (Delphinapterus leucas) and five Atlantic bottlenose dolphins (Tursiops truncatus) were presented stimuli well above threshold. The stimuli varied in type (tone versus pulse), amplitude, duration, and frequency. The average response time for bottlenose dolphins was 231.9 ms. The average response time for white whales was 584.1 ms. There was considerable variation between subjects within a species, but the difference between species was also found to be significant. In general, response times decreased with increasing stimulus amplitude. The effect of duration and frequency on response time was unclear. Two white whales (Delphinapterus leucas) and four Atlantic bottlenose dolphins (Tursiops truncatus) were given audiometric tests to determine masked hearing thresholds in open waters of San Diego Bay (Ridgway et al., 1997). Animals were tested at six frequencies over a range from 400 Hz to 30 kHz using pure tones. Hearing thresholds varied from 87.5 dB to 125.5 dB depending on the frequency, masking noise intensity and individual animal. At threshold, median response time across frequencies within each animal varied by about 150 ms. The two white whales responded significantly slower (∼670 msec, p<0.0001) than the four dolphins (∼410 msec). As in terrestrial animals, reaction time became shorter as stimulus amplitude increased (Wells, 1913; Stebbins, 1966). Across the two studies, the dolphins as a group were faster in the abovethreshold study than in the nearthreshold study. White whales had longer response times than bottlenose dolphins in both studies. Analysis of response time with an allometric relation based on weight shows that the difference in weight can explain a significant part of the difference in response time.
38

Study on the pH-sensing characteristics of the hydrogen ion-sensitive field-effect transistors with sol-gel-derived lead titanate series gate

Jan, Shiun-Sheng 15 November 2002 (has links)
The sol-gel-derived lead titanate (PbTiO3) membrane has been successfully applied as a novel pH-sensing layer to form the PbTiO3 gate ISFET (ion-sensitive field-effect transistor). There exhibit the excellent quasi-Nernstian response of 55-58 mV/pH, good surface adsorption and anticorrosion characteristics via the capacitance- voltage measurement of the electrolyte-insulator-semiconductor structure. At a specific pH concentration, the output and transfer characteristics of the PbTiO3 gate ISFET are very similar to the behaviours of MOSFETs (metal-oxide-semiconductor field-effect transistors), and the pH-ISFET model can be derived by the modified MOSFET model. As it operated in the nonsaturation region, there exhibits a linear pH response of about 55-58 mV/pH. Simultaneously, there exhibit the stable response time of 2-4 minutes, the drift of 0.5-1 mV/h, the hysteresis of 3-5 mV and the reduction rate of about ¡V10 mV/pH-day. On the other hand, as it operated in the saturation region, the pH responses and linearity can be controlled by adjusting the VGS values, e.g. the absolute pH response of 4.2, 24.8 and 31.3 uA/pH and the correlation coefficients of 0.9491, 0.9995 and 0.9996 at VGS= 1, 3 and 5 V can be obtained, respectively. Besides, the PbTiO3 gate ISFET has been modified by doping the Mg2+ and La3+ impurities into the PbTiO3 membrane. As a result, the former is a great benefit to improve the pH-sensing characteristics, which exhibits the pH response of 58-59 mV/pH, the drift of below 0.4 mV/h, the hysteresis of 1-3 mV and the reduction rate of -0.2 mV/pH-day. Finally, a digital pH meter has been successfully developed.
39

Vocal response times to acoustic stimuli in white whales and bottlenose dolphins

Blackwood, Diane Joyner 30 September 2004 (has links)
Response times have been used to explore cognitive and perceptual processes since 1850 (Donders, 1868). The technique has primarily been applied to humans, birds, and terrestrial mammals. Results from two studies are presented here that examine response times in bottlenose dolphins (Tursiops truncatus) and white whales (Delphinapterus leucas). One study concerned response times to stimuli well above the threshold of perceptibility of a stimulus, and the other concerned response times to stimuli near threshold. Two white whales (Delphinapterus leucas) and five Atlantic bottlenose dolphins (Tursiops truncatus) were presented stimuli well above threshold. The stimuli varied in type (tone versus pulse), amplitude, duration, and frequency. The average response time for bottlenose dolphins was 231.9 ms. The average response time for white whales was 584.1 ms. There was considerable variation between subjects within a species, but the difference between species was also found to be significant. In general, response times decreased with increasing stimulus amplitude. The effect of duration and frequency on response time was unclear. Two white whales (Delphinapterus leucas) and four Atlantic bottlenose dolphins (Tursiops truncatus) were given audiometric tests to determine masked hearing thresholds in open waters of San Diego Bay (Ridgway et al., 1997). Animals were tested at six frequencies over a range from 400 Hz to 30 kHz using pure tones. Hearing thresholds varied from 87.5 dB to 125.5 dB depending on the frequency, masking noise intensity and individual animal. At threshold, median response time across frequencies within each animal varied by about 150 ms. The two white whales responded significantly slower (∼670 msec, p<0.0001) than the four dolphins (∼410 msec). As in terrestrial animals, reaction time became shorter as stimulus amplitude increased (Wells, 1913; Stebbins, 1966). Across the two studies, the dolphins as a group were faster in the abovethreshold study than in the nearthreshold study. White whales had longer response times than bottlenose dolphins in both studies. Analysis of response time with an allometric relation based on weight shows that the difference in weight can explain a significant part of the difference in response time.
40

Does Crowding Obscure the Presence of Attentional Guidance in Contextual Cueing?

Fiske, Steven William 01 January 2012 (has links)
The contextual cueing effect was initially thought to be the product of memory guiding attention to the target location. However, the steep search slopes obtained in contextual cueing indicate an absence of attentional guidance. We hypothesized that crowding could be obscuring the presence of attentional guidance and investigated this possibility in 2 experiments. Crowding was manipulated by varying the density of items in the local target region in a contextual cueing task. We observed a significant reduction in search slopes between the novel and repeated conditions when crowding was reduced. Enhancing crowding eliminated the contextual cueing effect. These findings suggest that increased crowding at larger set sizes attenuates the memory-based attentional guidance in contextual cueing thereby producing steep search slopes.

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