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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.
181

Human chorionic gonadotropin and gonadotropin-releasing hormone influence pregnancy survival and resynchronized ovulation before timed artificial insemination in Holstein cattle

Buttrey, Brad Sterling January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / Jeffrey S. Stevenson / A study was performed to determine the minimum effective dose of human chorionic gonadotropin (hCG) needed to induce ovulation of follicles in cattle (Exp. 1). Another study determined the effects of replacing the first injection of GnRH (d -7) with hCG or saline in a Resynch-Ovsynch protocol [injection of GnRH 7 d before and 48 h after PGF[subscript2alpha] before a resynchronized fixed-timed AI (TAI)] on pregnancy rates in cows diagnosed not pregnant and pregnancy survival in cows diagnosed pregnant (d 0; Exp. 2). A final study determined the ovulation potential of hCG compared with GnRH and saline (Exp. 3). In Exp. 1, ovaries of Holstein cows were mapped by using transrectal ultrasonography 7 d before pregnancy diagnosis. Cows were assigned to treatments of saline, 100 [Mu]g of GnRH, or 500, 1,000, 2,000, or 3,000 IU of hCG. Ovarian structures were monitored 7 d later and proportion of cows and follicles that ovulated were recorded. In Exp. 2, cows in 4 herds were assigned to treatments of 1,000 IU of hCG, 100 [Mu]g of GnRH, or left as untreated controls 7 d before pregnancy diagnosis. Nonpregnant cows were given PGF[subscript2alpha] (d 0), then inseminated 72 h later, concurrent with a GnRH injection. Pregnancy rates tended (P = 0.08) to be increased by GnRH (17.9%; n = 703) compared with control (12.9%; n = 505), but not hCG (16.5%; n = 541). Incidences of ovulation in nonpregnant cows (Exp. 3) were: hCG (51.6%; n = 126), GnRH (46.1%; n = 102), and control (28.1%; n = 96), whereas those in pregnant cows were: hCG (59.3%; n = 59), GnRH (24.5%; n = 49), and control (6.9%; n = 58). We concluded that: 1) a minimum dose of 1,000 IU of hCG resulted in a greater ovulatory response than saline, GnRH, or 500 IU of hCG (Exp. 1); 2) initiating a Resynch-Ovsynch protocol 7 d before pregnancy diagnosis with saline reduced timed AI pregnancy rates (Exp. 2); and 3) incidence of new CL was greater after hCG than GnRH in pregnant cows, but not in nonpregnant cows (Exp. 3).
182

Emergence of Complexity from Synchronization and Cooperation

Geneston, Elvis L. 05 1900 (has links)
The dynamical origin of complexity is an object of intense debate and, up to moment of writing this manuscript, no unified approach exists as to how it should be properly addressed. This research work adopts the perspective of complexity as characterized by the emergence of non-Poisson renewal processes. In particular I introduce two new complex system models, namely the two-state stochastic clocks and the integrate-and-fire stochastic neurons, and investigate its coupled dynamics in different network topologies. Based on the foundations of renewal theory, I show how complexity, as manifested by the occurrence of non-exponential distribution of events, emerges from the interaction of the units of the system. Conclusion is made on the work's applicability to explaining the dynamics of blinking nanocrystals, neuron interaction in the human brain, and synchronization processes in complex networks.
183

Behavioral synchronization between dogs and owners.

Heurlin, Jasmine January 2019 (has links)
Dogs have lived with us for thousands of years, so we have learned to understand one another. Dogs have been shown to synchronize their behavior with humans. Behavioral synchronization is characterizes by doing the same thing at the same time and in the same place as someone else. This synchronization is often dependent on the relationship and the emotional state of the individuals. The main aim in this study was to develop a method to test behavioral synchronization and also to investigate how this, but also other behaviors, are effect by preceding human-dog interactions. Privately owned dogs (N=21) were tested with three different treatments (play, pet or ignore). The test procedure consisted of the owner walking or standing still in a predefined pattern, while their dog was freely roaming. This study showed that dogs adapted their movement pattern to their owners. This was similar to previous studies showing that the method developed can be used to test behavioral synchronization between owner and dog. Dogs explored the test arena less after play interaction and they also tended to seek more eye contact with their owners, but the interactions did not affect how much time spent in human proximity, how much they followed them or on dogs movement pattern.
184

Get In Sync With TSN : A Study of Partially Synchronized TSN Networks

Johansson, Andreas Johansson January 2022 (has links)
Automotive and industrial embedded systems are increasingly dependent on real-time capabilities. TSN aims to offer flexibility of the traffic by providing Ethernet with hard and soft real-time capabilities which allows for integration with other protocols in legacy systems. TSN requires the network to be fully synchronized to achieve high performance. However, there are cases where legacy systems are not able to synchronize with TSN. These systems might nonetheless be able to synchronize with each other through their legacy synchronization mechanisms. In this thesis, we have investigated effects in terms of jitter and clock drift in endpoints by synchronizing them with each other and passing communication through an unsynchronized intermediary TSN switch. Our results revealed that with the introduction of TSN, jitter was reduced, while clock drift between endpoints and the TSN switch was introduced. The results show that negative clock drift leads to packets missing their scheduled TSN windows and positive drift leads to packets being dropped in the switch buffer queues. We proposed two solutions in order to manage the experienced clock drift. In one solution we statically changed the switch cycle, and in the other, we let the receiver node dynamically update the sending period in the sender node. In the static solution, the clock drift was reduced from negative eight microseconds per second to two nanoseconds per second. In the dynamic solution, a packet error rate of one per 100 seconds was reduced to zero errors in 19 hours.
185

Dynamics and Synchronization of Motifs of Neuronal Populations in the Presence of Delayed Interactions

Lyra Gollo, Leonardo 20 July 2012 (has links)
Aquesta tesi estudia les propietats de sincronització de motius de neurones o poblacions de neurones acoblats amb retard. S'ha trobat que dos elements indirectament connectats de forma bidireccional a través d'un mediador de retransmissió dinàmica poden sincronitzar robustament la seva activitat a retard zero. L'efecte és estudiat en circuits especialment ben coneguts del cervell: xarxes corticals, circuits talamo-corticals i xarxes hipocampo-corticals. Els fonaments del mecanisme s'atribueixen a la influència de fonts ressonants: un parell d'elements directament acoblats bidireccionalment. En la presència de latència no negligible, la parella acoblada tendeix a sincronitzar en anti-fase. Aquesta propietat prevalent, intrínsecament dota a cada element amb una capacitat potencial de induir òptimament una sincronització isocrònica entre dos elements comunament conduïts. Aquest efecte, anomenat Sincronització Induïda per Ressonància, s'observa consistentment en diversos sistemes, sempre que hi hagi absència de frustració geomètrica en l'arquitectura estructural / Esta tesis estudia las propiedades de sincronización de motivos de neuronas, o de las poblaciones neuronales, acopladas con un cierto retraso. Se ha encontrado que dos elementos indirectamente conectados de forma bidireccional, a través de un mediador dinámico, pueden sincronizar de forma robusta sus actividades a tiempo cero. El efecto se estudia en circuitos del cerebro que se sabe juegan un papel fundamental: las redes corticales, circuitos tálamo-corticales y las redes hipocampo-corteza. Los fundamentos del mecanismo se atribuyen a la influencia de las fuentes de resonancia: un par de elementos bidireccionalmente acoplados. En presencia de tiempos de latencia no despreciable, el par de neuronas o poblaciones de neuronas acopladas tiende a sincronizar en oposición de fase. Esta característica predominante intrínsecamente dota a cada uno de los elementos con una capacidad potencial de inducir, de manera óptima, sincronización isócrona entre los elementos comúnmente dirigidos. Esta sincronización inducida por resonancia se observa consistentemente en varios sistemas, cuando ocurre que la frustración geométrica está ausente de la arquitectura estructural. / This thesis studies the synchronization properties of delay-coupled motifs of neurons or neuronal populations. It is found that two elements indirectly bidirectional-connected through a dynamical-relaying mediator can robustly synchronize their activity at zero-lag. The effect is studied in special well-known circuits of the brain: cortical networks, thalamocortical circuits, and hippocampal-cortical networks. The foundations of the mechanism are ascribed to the influence of resonant sources: a pair of directly bidirectional-coupled elements. In the presence of non-negligible latency, the coupled pair tends to synchronize in anti-phase. This prevalent property intrinsically endows each of the elements with a potential capability to optimally induce isochronous synchronization between commonly driven elements. This, so-called Resonance-Induced Synchronization, is consistently observed in distinct systems, whenever geometrical frustration is absent of the structural architecture
186

Chaotic optical communications using delayed feedback systems

Locquet, Alexandre Daniel 11 January 2006 (has links)
Chaotic dynamics produced by optical delay systems have interesting applications in telecommunications. Optical chaos can be used to transmit secretly, in real-time, a message between an emitter and a receiver. The noise-like appearance of chaos is used to conceal the message, and the synchronization of the receiver with the chaotic emitter is used to decode the message. This work focuses on the study of two crucial topics in the field of chaotic optical communications. The first topic is the synchronization of chaotic external-cavity laser diodes, which are among the most promising chaotic emitters for secure communications. It is shown that, for edge-emitting lasers, two drastically different synchronization regimes are possible. The regimes differ in terms of the delay time in the synchronization and in terms of the robustness of the synchronization with respect to parameter mismatches between the emitter and the receiver. In vertical-cavity surface-emitting lasers, the two linearly-polarized components of the electric field also exhibit isochronous and anticipating synchronization when the coupling between the lasers is isotropic. When the coupling is polarized, the linearly-polarized component that is parallel to the injected polarization tends to synchronize isochronously with the injected optical field, while the other component tends to be suppressed, but it can also be antisynchronized. The second topic is the analysis of time series produced by optical chaotic emitters subjected to a delayed feedback. First, we verify with experimental data that chaos produced by optical delay systems is highly complex. This high complexity is demonstrated by estimating chaos dimension and entropy from experimental time series and from models of optical delay systems. Second, by analyzing chaotic time series, it is shown that the value of the delay of a single-delay system can always be identified, independently of the type of system used and of its complexity. Unfortunately, an eavesdropper can use this information on the delay value to break the cryptosystem. We propose a new cryptosystem with two delayed feedback loops that increases the difficulty of the delay identification problem.
187

Comparison of short-term vs. long-term estrous synchronization protocols using CIDR devices in sheep and goats during and outside the natural breeding season

Harl, Audra Whitney January 1900 (has links)
Master of Science / Department of Animal Science and Industry / David M. Grieger / Controlling reproductive cycles during active cyclicity and seasonal anestrous in small ruminants is critical for profitability. The objective of this study was to evaluate the effect on estrous response and interval to estrus of two CIDR protocols in sheep and goats during breeding and non-breeding seasons. In experiment 1, 133 ewes were randomly assigned to 1 of 3 treatments during the breeding season. In the CIDR-7 group, ewes received a CIDR insert for 7 d. In the CIDR-7 + PGF treatment, ewes received a CIDR insert for 7 d and 20 mg of prostaglandin-F[subscript]2[subscript]α (PGF[subscript]2[subscript]α) upon CIDR removal. Ewes in the CIDR-14 treatment received a CIDR insert for 14 d. Following CIDR removal all ewes were exposed to a ram every 12 h until breeding. There was a shorter interval from CIDR removal to estrus in the CIDR-14 treatment compared to the CIDR-7 and CIDR-7 + PGF treatments (P<0.05). There was no difference in number of ewes per treatment displaying estrus. In experiment 2, 54 ewes were randomly assigned to one of two treatment groups during the anestrous season. Ewes in CIDR-7 and CIDR-14 treatments received a CIDR insert for 7 d and 14 d, respectively. Upon CIDR removal ewes were exposed to a ram every 12 h until breeding. There was a significantly shorter interval from CIDR removal to estrus in CIDR-14 ewes when compared with CIDR-7 ewes (P<0.05). For experiment 3, 37 Boer does were randomly assigned to one of two treatments. In the CIDR-10 treatment, does received a CIDR insert for 10 d and 20 mg of PGF[subscript]2[subscript]α at time of CIDR removal. In the CIDR-19 treatment, does received a CIDR insert for 19 d. Upon CIDR removal, does were exposed to a buck fitted with a marking harness and chalk marks were recorded every 12 h. The number of does displaying estrus was not different (CIDR-7, 85%; CIDR-14, 95%). There was no difference in interval from CIDR removal to estrus between treatments. Results from experiments 1 and 2 supported the hypothesis that long-term protocols yield a shorter interval to estrus when compared with short-term protocols.
188

IEEE1588 – A solution for synchronization of networked data acquisition systems?

Corry, Diarmuid 10 1900 (has links)
ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / One of the problems for manufacturers and users of flight test data acquisition equipment, is to guarantee synchronization between multiple units acquiring data on the vehicle. Past solutions have involved proprietary interconnects and multiple wire installations increasing weight and complexity and reducing inter-operation of units. This problem has become particularly important given the trend towards commercial busses, especially Ethernet, as a system interconnect. The IEEE1588 standard offers a way to transmitting time accurately over Ethernet. This paper discusses the standard, how it might be implemented, and examines the issues involved in adopting this standard for flight test data acquisition. A particular implementation that results in a synchronized four-wire Ethernet based distributed data acquisition system is discussed in section 3.
189

Towards a Low Complexity Implementation of a Multi-H CPM Demodulator

Guéguen, Arnaud, Auvray, David 10 1900 (has links)
ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Multi-h Continuous Phase Modulation (CPM) is a promising waveform for aeronautical telemetry because it is a compact spectrally efficient constant amplitude modulation. It has been selected as the Advanced Range Telemetry (ARTM) tier II waveform owing to these qualities. However, it is also a complicated waveform that has the reputation of suffering from complex demodulation processing and high sensitivity to transmission impairments and in particular synchronization aspects. In this paper we review a set of complexity reduction techniques that intend to bring this waveform into the domain of operational telemetry waveform, by allowing low complexity hardware implementation without sacrificing performance or robustness. Most techniques are adjustments of recent literature results, concerning both demodulation and synchronization. Computer simulation of a receiver implementing theses techniques shows negligible performance loss compared to optimal coherent demodulation with perfect synchronization. Hardware implementation confirms that nearly optimal performance can be achieved with hardware resource currently available in middle range FPGAs.
190

A HIGH-ACCURACY AND LOW-COMPLEXITY CARRIER-OFFSET-FREQUENCY ESTIMATOR

Palmer, Joseph 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / A single-tone frequency estimator for a non-uniformly sampled sinusoid is proposed. A nonuniformly sampled sinusoid may be generated from the received training sequences of a telemetry link. The frequency of the sinusoid matches the carrier-frequency-offset (CFO) of the received signal, and estimation of this quantity allows a receiver to compensate for the CFO. The performance bounds of this type of estimator have been investigated in the literature, though little work has been published on practical algorithms. The estimator proposed in this paper is a generalization of phase-increment estimators previously described in the literature. It exhibits a low computational complexity yet converges to theoretical bounds at high SNR. The paper argues that a periodic training sequence structure, combined with the new estimator, allows for a high-accuracy and lowcomplexity CFO compensator.

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