With post-bloom chemical fruit thinning responses being heavily influenced by tree carbohydrate reserves and weather conditions, there is a need for alternative thinning practices such as chemical blossom thinning in the Mid-Atlantic apple growing region. This project sought to 1) evaluate timing strategies for lime sulfur + stylet-oil blossom thinning sprays and 2) screen chemical agents for their suitability and efficacy as blossom thinners. In the first study, two 'Gala'/'M.9' blocks in different states (North Carolina and Virginia) were utilized in 2019 to compare between pollen tube growth model-guided blossom thinning sprays and those that are based on fixed time intervals between the initial application and subsequent thinning sprays. It was generally found that model-guided blossom thinning sprays and sprays applied at 20% open bloom and 48 hours after reduced fruit set, crop load, and improved fruit weight. In the second study, a 'Honeycrisp'/'B.9' and 'Cripps Pink'/'M.9' apple block in Virginia were used in 2018 and 2019 to evaluate multiple chemical agents with and without stylet-oil. Most of the treatments under-thinned compared to untreated control trees. However, it was determined that ammonium thiosulfate with and without stylet-oil was the most effective thinning agent. Potassium bicarbonate + stylet-oil was observed to cause excessive fruit russeting and phytotoxicity. This project demonstrated that optimum apple crop loads can be obtained if lime sulfur + stylet-oil blossom thinning sprays are applied at the proper time, and that multiple chemical agents offer potential use for chemical blossom thinning in the Mid-Atlantic region / Master of Science in Life Sciences / For apple trees to produce high quality fruit, a proportion of the flowers and/or fruit must be removed in a practice known as "thinning". Chemical blossom thinning is a relatively new method of thinning in the Mid-Atlantic apple growing region. This project sought to 1) evaluate spray timing of blossom thinning sprays and 2) evaluate different chemicals for their suitability in blossom thinning. In the first study, two 'Gala' apple orchards in two states (North Carolina and Virginia) were utilized in 2019 to compare a computer model-guided spray timing to structured spray timings based on the amount of time between the first and second sprays. It was found that the model-guided sprays, and sprays occurring once 20% of the blossoms had opened and reapplied 48 hours after, were the most effective in thinning the flowers. In the second part of the study, a 'Honeycrisp' orchard and a 'Cripps Pink' orchard in Virginia were used in 2018 and 2019 to evaluate different chemicals for their potential as blossom thinners. Unfortunately, most of the treatments did not achieve sufficient thinning results compared to untreated trees. However, it was determined that ammonium thiosulfate with and without stylet-oil was the most effective thinning chemical. Potassium bicarbonate with stylet-oil was found to cause excessive injury to the fruit and foliage. This project demonstrated that blossom thinning can be effective when the sprays are applied at the correct time and that multiple chemical agents offer potential for blossom thinning in the Mid-Atlantic.

La thèse vise à identifier, dans un premier temps, l’influence du timing de versement des dividendes des sociétés françaises cotées sur les cours boursiers. Elle cherche à identifier, dans un deuxième temps, les déterminants du timing de versement des dividendes. La démarche retenue pour argumenter ces propos est la suivante : dans une première partie, nous avons posé notre cadre théorique. Le positionnement de la thèse dans l’ancrage de la théorie politico-contracteulle et la théorie des signaux nous a orienté vers l’étude du contenu informationnel du timing de versement des dividendes dans un premier temps et à identifier ses déterminants dans un deuxième temps. La seconde partie est consacrée à l’étude empirique réalisée auprès de 69 entreprises initiatrices de dividendes cotées à l’indice SBF 120 durant l’année 2007 afin de répondre à notre premier objectif, et portée sur un échantillon de 57 sociétés françaises distributrices d’un dividende annuel durant la période 2003-2009 afin de répondre à notre second objectif. S’agissant de notre premier objectif, le recours à la méthodologie des études d’évènement a révélé que les cours réagissent à la date de versement des dividendes ce qui confirme que le timing de versement des dividendes possède un contenu informationnel. Quant à notre second objectif, les dispositions réglementaires souples sur la fixation de la date de versement du dividende et son emploi en tant que signal émis de la firme vers le marché posent la question du choix de cette date dans le contexte français à système juridique civil connu pour la protection des intérêts des actionnaires minoritaires. Les résultats de la littérature antérieure restent timides en raison de leur focalisation sur la date de versement du premier dividende – et notamment sur la probabilité d’initier un dividende suite à l’introduction en bourse. Les résultats de notre étude empirique confirment l’impact significatif de la présence d’un actionnaire majoritaire, de la profitabilité, de la liquidité et de la durée de versement du dividende précédent sur la fixation de la date de versement de cette année. Cet impact semble se manifester à travers une limitation de la durée entre la date de l’assemblée des actionnaires et la date de paiement effectif des dividendes et une reconnaissance de cette durée comme étant une bonne nouvelle par rapport aux autres signaux émis par l’entreprise au marché boursier. / The purpose of this study is to identify the informational content of the dividend pay date and its determinants. Namely, is there information in the timing of the dividend payments? The empirical evidence indicates that the market reacts at the dividend pay date. Mean excess returns of stock prices on the pay date are significantly positive and are insignificant and negative around the entire population of dividend pay dates. On the other side we are interested in the determinants of the dividend pay date. Our multivariate analysis shows that the ownership structure, the liquidity of the firm, the result, and the previous timing of dividend payment influence the fixing of the dividend pay date. This impact is shown as shorten as the delay between the date of the general meeting and the dividend pay date. This duration is considered as good news and can be a signal employed to attract new investors in the stock market.

Syftet med föreliggande studie är att undersöka timing som aspekt av och transkription i relation till musik i tempo rubato. I studien undersöks en fyra veckor lång instuderingsperiod där ett stycke musik i tempo rubato lärdes in med utgångspunkt i en ljudande förlaga. Studien utgår från ett fenomenologiskt livsvärldsperspektiv och resultatet grundar sig på loggboksanteckningar samt ljud- och videoinspelningar från övningsperioden. Resultatet presenteras utifrån temana instudering och inlärning och utförande, och visar att olika instuderingsmetoder använts med olika syften, att inlärningen starkt påverkas av tidigare erfarenheter samt att musikens avsaknad av stadig puls medförde svårigheter som inte uppkommer i instudering av musik där tempot och pulsen är mer konsekvent. I resultatet framkommer även att transkriptionen haft stor inverkan på instuderingen genom det förhållande som finns mellan transkriptionen och upplevelsen av musiken. Slutligen diskuteras timing och transkription utifrån litteratur och tidigare forskning i ämnet, med tonvikt på livsvärldsperspektivet. / The purpose of the present study is to examine timing as an aspect of and transcription in relation to music in tempo rubato. The study examines a four week learning period wherein a piece of music in tempo rubato was practiced with the original recording being used as the starting point. The study is based on the phenomenological life world theory and its results are based on logbook entries as well as audio and video recordings made during the practice period. The results are presented from the themes studying and learning and performance and show that different practice methods were used for different purposes, that the learning process was strongly affected by earlier experiences and that the absence of a steady pulse in the music brought about difficulties that don’t occur in the study of music where the tempo and pulse is more consistent. The results also show that the transcription had a great impact on the learning process through the relation between the transcription and the experience of the music. Lastly, timing and transcription is discussed through literature presented in the background chapter, with an emphasis on the life world theory.

Os modelos básicos da MPR são usados como blocos de construção de uma máquina estocástica que simula o responder operante. A máquina-MPR é então testada sob uma ampla variedade de condições experimentais, e prova sua capacidade de produzir com realismo: (a) distribuições de IRT, (b) padrões do responder intra-sessão, e (c) as relações entre taxa de reforçamento e taxa de resposta sob esquemas de intervalo e de razão. Em outro conjunto de experimentos, o modelo demonstra propriedades emergentes realistas e reproduz fenômenos bem conhecidos no âmbito dos esquemas múltiplos, como (d) contraste comportamental e (e) desaceleração da extinção ambos além do alcance original da MPR. No último capítulo do estudo, a máquina-MPR é dotada de um modelo de controle temporal. Essa nova configuração, chamada tMPR, se mostra capaz de simular (f) o comportamento de timing que emerge sob esquemas previsíveis de intervalo, assim como (g) as propriedades centrais desse tipo de comportamento. O poder de abarcar um vasto domínio de fenômenos operantes com um mecanismo simples que roda sobre um conjunto de parâmetros com valores fixos e o fato de que ela faz isso a partir de uma arquitetura que pode ser facilmente expandida, faz da máquina-MPR uma plataforma útil para a integração de teorias. À medida que outros pesquisadores enriquecerem o framework com novos módulos, ele poderá ajudar a elucidar como diferentes aspectos do comportamento operante interagem uns com os outros, pavimentando a transição de uma análise do comportamento para uma síntese comportamental. / The basic models of MPR are used as the building blocks of a stochastic machine that simulates operant responding. The MPR-machine is then tested under a wide variety of experimental conditions, and proves its ability to produce realistic (a) IRT distributions, (b) within-session patterns of responding, and (c) relations between reinforcement rate and response rate under interval and ratio schedules. In another set of experiments, the model show realistic emergent properties and reproduces well known multiple schedule phenomena, such as (d) behavioral contrast and (e) extinction deceleration all of them beyond the original reach of MPR. In the last chapter of the study, the MPR-machine is embodied with a model of temporal control. The new configuration, named tMPR, proves itself able to simulate (f) the timing behavior that arises under predictable interval schedules as well as (g) the central properties of this behavior. The power to account for a vast domain of operant behavior phenomena with a simple mechanism that runs on a fixed set of parameter values and the fact that it does so based on an architecture that can be easily expanded to accommodate new models makes the MPR-machine a useful platform for theory integration. As other researchers enrich the framework with new modules, it may help to elucidate how different aspects of operant behavior interact with one another, paving the transition from a behavior analysis to a behavioral synthesis.

Dans l’industrie, des méthodes de Maîtrise Statistique des Procédés (MSP) sont utilisées pour savoir si des pièces usinées lors d’un processus de fabrication sont non conformes aux spécifications. Les deux méthodes utilisées sont la méthode de Shewhart et la méthode EWMA (moyenne mobile à pondération exponentielle). Une adaptation de ces deux méthodes à la bourse est faite pour créer un modèle qui anticipe les cours sur les marchés à termes de matières premières. Ces deux méthodes sont utilisées simultanément, ce qui est une première. Le modèle présenté différencie plusieurs types de mouvements et plusieurs types d’investisseurs sur les marchés. C’est un modèle prudent. L’obtention de fortes performances est importante mais la diminution du risque et la limitation des pertes le sont également. Une simulation de la gestion d’un portefeuille pouvant être investi dans douze marchés à terme est faite. Ces marchés sont les suivants : le gaz naturel, le pétrole, le blé, le maïs, le soja, le bois, le jus d’orange concentré surgelé, le café, le cacao, le sucre, le coton et le cuivre. Cette simulation dans laquelle le portefeuille n’est pas « en levier » donne des résultats impressionnants. La simulation est faite du 3 janvier 2000 au 31 décembre 2013. Le capital initial est de $ 10 000 000 et à la fin de la simulation il est de $ 189 868 766. Le taux de rendement actuariel est de 23%. La seule rentabilité annuelle négative est celle de 2013 (-0.5%) et la meilleure est celle de 2010 (67%) La volatilité annualisée est de 17%. Le ratio d’information est exceptionnel : 0.85 ! La capacité au market-timing est de 47%. Ce pourcentage est ordinaire mais il recouvre le fait que la performance moyenne d’une position gagnante est de 17% tandis que celle d’une position perdante est de -6%. La performance d’une position gagnante compense, en moyenne, celle de trois positions perdantes. / Methods of Statistical Process Control (SPC) are used in the industrial sector to know if work pieces are conforms to specifications. Two methods are used: the Shewhart method and the Exponentially-weighted moving average method (EWMA). An adaptation of these methods to the financial markets is done to create a model which anticipates prices on commodities markets. Both methods are used simultaneously which is the first time. The developed model distinguishes several types of market movements and various types of investors. It is a safe model. Obtaining strong performances is important but reducing risk and limiting losses are too. A simulation of the management of a portfolio which may be invested of twelve commodities is done. The markets are: natural gas, oil, wheat, corn, soybeans, lumber, frozen concentrated orange juice, coffee, cocoa, sugar, cotton and copper. We decide to simulate a portfolio without “leverage” and results are impressive. The simulation is done from January 3rd 2000 to December 31th 2013. The initial capital of the portfolio is $ 10,000,000 and at the end of the simulation is $ 189,868,766. The rate of annual return is 23%. The only negative annual return is that of 2013 (-0.5%) and the best is that of 2010 (67%). The annualized volatility is 17%. The information ratio is exceptional: 0.85! The ability to market timing is 47%. This percentage is ordinary, but the average performance of winning positions is 17% while that of a losing position is -6%. The performance of a winning position, on average, corrects that of three losing positions.

This paper investigates how CEOs in public Swedish mid-cap corporations time their transactions in their own company’s stock in a short-term perspective. To investigate this, an event study methodology is employed on cumulative returns surrounding these insiders’ transactions, both absolute and relative to the market. We find that these insiders, on average, purchase stock subsequent to a period of decline in both total and abnormal cumulative returns and sell stock following a period of positive total and abnormal returns. This is in line with our hypotheses. We also find that total and abnormal cumulative returns tend to turn and increase for a short period following a purchase transaction, while for a sale transaction, the trend does not turn but continues upward, implying that purchases may be timed more rigorously in the short run than sales. This paper discusses these observations in connection to earlier findings and motivates further research on the subject of insider transaction timing.

In this thesis, the recently discovered Soft Gamma Ray Repeaters SGR J1833-0832, SWIFT J1822.3-1606 and SWIFT J1834.9-0846 are analysed using the archival Swift, RXTE, Chandra and XMM-Newton observations. The period fluctuations and timing noise properties of these sources are investigated. Spectral characteristics and long term frequency evolution of these sources are presented. Investigation for timing noise structure of these magnetars has shown a correlation between first frequency derivative of the spin frequency and torque noise strength.

The recent advance in Field Programmable Gate Array (FPGA) technology has been largely embraced by the communication industry, which views this technology as an effective and economical alternative to the design of Application Specific Integrated Circuits (ASICs). The primary reasons for switching to FPGAs are lower development and non-recurring engineering costs, the flexibility to design to a preliminary standard and adapt the design as the standard evolves, as well as the option of performing software updates in the field.<p> A sector with strong interest in FPGAs is the coaxial cable TV/Internet distribution industry. The creation of soft preliminary standards by the standards organization governing the industry has been the main catalyst for the massive adoption of FPGAs by small to medium size companies, which see this technology as an opportunity to compete in this open market.<p> Both the circuit speed and the economy of FPGA technology depend upon using algorithms that map efficiently into its fabric. Often it is prudent to sacrifice performance to improve either clock speed or economy when developing with FPGAs. The purpose of this research is to both revise and devise synchronization algorithms / structures for cable digital receivers that are to be implemented in FPGA. <p> The main communication scheme used by the coaxial cable distribution industry is digital Quadrature Amplitude Modulation (QAM). The problem of synchronizing to the QAM signal in the receiver is not a new topic and several synchronization-related circuits, which were devised with ASICs implementation in mind, can be found in the open literature. Of interest in this thesis is the non-data-aided digital timing synchronizer that was proposed by D'Andrea to recover timing with no knowledge of the transmitted data. Accurate timing estimation was achieved by reshaping the received signal with a prefilter prior to estimating the timing. <p> A problem with D'Andrea's synchronizer is that the prefilter for reshaping the signal is a relatively long Finite Impulse Response (FIR) filter, whose implementation requires a large number of multipliers. This may not have been an issue with ASICs in as much as the number of hardwired multipliers on a chip is not limited as it is in an FPGA chip. One contribution in this research is to propose an alternative to D'Andrea's synchronizer by replacing the long FIR filter with two single-pole Infinite Impulse Response (IIR) filters that are directly placed inside the timing recovery loop. This novel architecture, which drastically reduces the number of multipliers, is well suited for FPGA implementation.<p> Non-data-aided feedforward synchronizers, which use the same prefilter as D'Andrea's synchronizer, have been receiving significant attention in recent years. Detailed performance analysis for these synchronizers can be found in the open literature. These synchronizers have the advantage of using a feedfordward structure rather than a feedback structure, as it is the case in D'Andrea's synchronizer, to estimate the timing. While D'Andrea's synchronizer has an advantage in performance over a non-data-aided feedforward synchronizer, this has not been reported in the literature. In this thesis a second contribution consists of thoroughly analyzing the steady state timing jitter in D'Andrea synchronizer by deriving a closed-form expression for the noise power spectrum and a simple equation to estimate the timing jitter variance. <p> A third contribution is a novel low-complexity and fast acquisition coherent detector for the detection of Quadrature Phase Shift Keying (QPSK) (i.e., 4-QAM) symbols. This detector performs carrier phase synchronization much faster than a conventional coherent detector. The acquisition time is comparable to that of a differential detector. The fast acquisition comes at the expense of phase jitter, and the end result is a 1 dB performance loss over theoretical coherent detection. This detector can be used in place of the differential detector with no economic penalty. Doing so yields a performance advantage of about 2 dB over differential detection.

The recent advance in Field Programmable Gate Array (FPGA) technology has been largely embraced by the communication industry, which views this technology as an effective and economical alternative to the design of Application Specific Integrated Circuits (ASICs). The primary reasons for switching to FPGAs are lower development and non-recurring engineering costs, the flexibility to design to a preliminary standard and adapt the design as the standard evolves, as well as the option of performing software updates in the field.<p> A sector with strong interest in FPGAs is the coaxial cable TV/Internet distribution industry. The creation of soft preliminary standards by the standards organization governing the industry has been the main catalyst for the massive adoption of FPGAs by small to medium size companies, which see this technology as an opportunity to compete in this open market.<p> Both the circuit speed and the economy of FPGA technology depend upon using algorithms that map efficiently into its fabric. Often it is prudent to sacrifice performance to improve either clock speed or economy when developing with FPGAs. The purpose of this research is to both revise and devise synchronization algorithms / structures for cable digital receivers that are to be implemented in FPGA. <p> The main communication scheme used by the coaxial cable distribution industry is digital Quadrature Amplitude Modulation (QAM). The problem of synchronizing to the QAM signal in the receiver is not a new topic and several synchronization-related circuits, which were devised with ASICs implementation in mind, can be found in the open literature. Of interest in this thesis is the non-data-aided digital timing synchronizer that was proposed by D'Andrea to recover timing with no knowledge of the transmitted data. Accurate timing estimation was achieved by reshaping the received signal with a prefilter prior to estimating the timing. <p> A problem with D'Andrea's synchronizer is that the prefilter for reshaping the signal is a relatively long Finite Impulse Response (FIR) filter, whose implementation requires a large number of multipliers. This may not have been an issue with ASICs in as much as the number of hardwired multipliers on a chip is not limited as it is in an FPGA chip. One contribution in this research is to propose an alternative to D'Andrea's synchronizer by replacing the long FIR filter with two single-pole Infinite Impulse Response (IIR) filters that are directly placed inside the timing recovery loop. This novel architecture, which drastically reduces the number of multipliers, is well suited for FPGA implementation.<p> Non-data-aided feedforward synchronizers, which use the same prefilter as D'Andrea's synchronizer, have been receiving significant attention in recent years. Detailed performance analysis for these synchronizers can be found in the open literature. These synchronizers have the advantage of using a feedfordward structure rather than a feedback structure, as it is the case in D'Andrea's synchronizer, to estimate the timing. While D'Andrea's synchronizer has an advantage in performance over a non-data-aided feedforward synchronizer, this has not been reported in the literature. In this thesis a second contribution consists of thoroughly analyzing the steady state timing jitter in D'Andrea synchronizer by deriving a closed-form expression for the noise power spectrum and a simple equation to estimate the timing jitter variance. <p> A third contribution is a novel low-complexity and fast acquisition coherent detector for the detection of Quadrature Phase Shift Keying (QPSK) (i.e., 4-QAM) symbols. This detector performs carrier phase synchronization much faster than a conventional coherent detector. The acquisition time is comparable to that of a differential detector. The fast acquisition comes at the expense of phase jitter, and the end result is a 1 dB performance loss over theoretical coherent detection. This detector can be used in place of the differential detector with no economic penalty. Doing so yields a performance advantage of about 2 dB over differential detection.

Timing recovery is the processing of synchronizing the sampler with the received analog signal. Sampling at the wrong times can have a devastating impact on performance. Conventional timing recovery techniques are based on a decision-directed phase-locked loop (PLL). They are adequate only when the operating signal-to-noise ratio (SNR) is sufficiently high, but recent advances in error-control coding have made it possible to communicate reliably at very low SNR, where conventional techniques fail. This thesis develops new techniques for timing recovery that are capable of working at low SNR. We propose a new timing recovery scheme based on per-survivor processing (PSP), which jointly performs timing recovery and equalization, by embedding a separate PLL into each survivor of a Viterbi algorithm. The proposed scheme is shown to perform better than conventional scheme, especially when the SNR is low and the timing error is large. An important advantage of this technique is its amenability to real-time implementation. We also propose a new iterative timing recovery scheme that exploits the presence of the error-control code; in doing so, it can perform even better than the PSP scheme described above, but at the expense of increased complexity and the requirement of batch processing. This scheme is realized by embedding the timing recovery process into a trellis-based soft-output equalizer using PSP. Then, this module iteratively exchanges soft information with the error-control decoder, as in conventional turbo equalization. The resulting system jointly performs the functions of timing recovery, equalization, and decoding. The proposed iterative timing recovery scheme is shown to perform better than previously reported iterative timing recovery schemes, especially when the timing error is severe. Finally, performance analysis of iterative timing recovery schemes is difficult because of their high complexity. We propose to use the extrinsic information transfer (EXIT) chart as a tool to predict and compare their performances, considering that the bit-error rate computation takes a significant amount of simulation time. Experimental results indicate that the system performance predicted by the EXIT chart coincides with that obtained by simulating data transmission over a complete iterative receiver, especially when the coded block length is large.