The apple tree is the most common fruit crop in the temperate climate zone. Modern intensive fruit cultivation involves the use of new, highly productive cultivars and cultivation technologies, ...thanks to the creation of small crown shapes with an increased number of trees per hectare. Reducing planting patterns and creating more dense plantation systems can significantly improve their yields. However, the limiting factor that can reduce tree productivity and deteriorate fruit quality is the degree of crown illumination. Ensuring even access of sunlight to all parts of the crown is the main task in the formation and pruning trees. The study aimed to determine the effect of crown pruning at BBCH 0 (winter) and BBCH 74 (early summer) and various types of crown formation on the growth activity and productivity of ‘Fuji’ and ‘Honeycrisp’ apple trees. A significant decrease (20%) in the number of newly formed shoots in the form of the French axis crown compared to the ballerina and slender spindle crowns was found. However, their length and total growth were significantly higher. The formation of the ballerina crown (with the removal of overgrown wood in the 25 cm zone on the central conductor above the lower tier of semi-cross-branched branches) contributed to a decrease in shoot length and total growth. The introduction of crown pruning in the summer also improved crown illumination – shoot length decreased by 17% and total growth by 12%. Specific productivity per bole cross-section and total shoot length was the highest in ballerina crown trees, followed by trees with a slender spindle crown, and trees pruned in winter and summer.
Dans cette thèse, la mesure des propriétés du boson de Higgs dans le canal de désintégration en deux photons avec l'expérience CMS au Grand Collisionneur de Hadrons (LHC) est présentée. L'objectif de ...ce travail est l’étude du mode de production associé à une paire de quark top (tṫH). Ce mode représente le seul accès direct au couplage de Yukawa du quark top, un paramètre fondamental du Modèle Standard. Le mode de production tṫH est un processus très rare. Il est de l'ordre de deux ordres de grandeur plus petits que la production principale du boson de Higgs par fusion de gluons. À 13 TeV, le mode de production ttH est environ 4 fois plus grand qu'à 8 TeV. Cette thèse reprend les études réalisées à 8 TeV, où l’échantillon de données ne suffisait pas pour établir une observation de ce mode de production. Bien que le canal en deux photons ne soit pas celui qui présente le plus grand rapport de branchement (seulement 0,2%), il est très prometteur en raison de son excellente résolution en masse (1%). De plus, sa signature est très propre dans le détecteur. Le canal de désintégration en deux photons est particulièrement intéressant puisqu'il s'agit du seul canal permettant l'étude de tous les modes de production : la fusion de gluons, la fusion de bosons vecteurs, les productions associées avec des bosons W ou Z ou avec une paire de quarks top. Le document commence par une introduction théorique du Modèle Standard et la physique du boson de Higgs au LHC, suivie d'une description du détecteur CMS. Pour obtenir une excellente résolution de masse dans le canal de désintégration en deux photons , le calorimètre électromagnétique doit être calibré. Le système de monitorage de la transparence des cristaux du calorimètre électromagnétique de CMS par le système laser joue un rôle important dans la chaîne d'étalonnage et est décrit en détail. Sur le long terme, le système de monitorage laser devra être amélioré car le niveau de rayonnement influence son électronique. Je présente mon travail sur l'amélioration possible du système de monitorage laser, ainsi que l'étude de sa précision possible. L'analyse inclusive H → ᵞᵞ a eu plusieurs itérations pour les conférences en 2016 et 2017. La stratégie pour 2017 est décrite dans ce document. Une classification des événement sert à maximiser la significance du signal et à étudier les modes spécifiques de production du boson de Higgs. Mes contributions à l'analyse H → ᵞᵞ consistent en l'identification du vertex primaire, l'identification du photon et l'étude du mode de production tṫH. Chaque contribution est décrite en détail dans des chapitres dédiés. L'analyse tṫH, H → ᵞᵞ est présentée pour deux itérations en 2016 et 2017, en mettant l'accent sur les améliorations dans l'analyse de 2017. Enfin, les résultats de l'analyse inclusive et tṫH, H → ᵞᵞ, en utilisant l'ensemble complet de données 2016 correspondant à une luminosité intégrée de 35,9 fb-1, sont présentés.
In this thesis, the measurement of the Higgs boson properties in the diphoton decay channel with the CMS experiment at the Large Hadron Collider (LHC) is presented. The focus of this work is the tṫH production mode, as it is the only direct access to the top quark Yukawa coupling, a fundamental parameter of the Standard Model. tṫH is a very rare process, two orders of magnitude smaller than the dominant Higgs boson production by gluon fusion. At 13 TeV, ttH production is about 4 times larger than at 8 TeV. This thesis takes over the studies performed at 8 TeV, where the statistics was not enough for an observation of ttH. Despite a very small branching ratio (only about 0.2%), the two photons decay channel of the Higgs boson is very promising, because of its excellent mass resolution (about 1%). Moreover, its signature in the detector is very clear. The diphoton decay channel is also of particular interest as it is the only channel allowing the study of all production modes: gluon fusion, vector boson fusion, associated productions with a W or a Z bosons, or with a top quark pair.The document starts with a theoretical introduction about the Standard Model and Higgs boson physics at LHC, followed by a description of the CMS detector. To achieve an excellent mass resolution in the H → ᵞᵞ channel, the electromagnetic calorimeter has to be calibrated. The laser monitoring system plays an important role in the calibration chain and it is described in details. On the long term, the laser monitoring system will have to be upgraded as level of radiation influences its electronics. I present my work on the possible upgrade of the laser monitoring system, along with the study of its possible precision.H → ᵞᵞ inclusive analysis had several iterations for conferences in 2016 and 2017. The strategy for 2017 is described in this document. An event classification is used to maximize the signal significance and to study specific Higgs boson production modes. My contributions to the H → ᵞᵞ analysis are primary vertex identification, photon identification and the study of the tṫH production mode. Each contribution is described in details in dedicated chapters. The tṫH, H → ᵞᵞ analysis is shown for two iterations in 2016 and 2017, with the emphasis on improvements in 2017 analysis. Finally, the results of the inclusive and tṫH, H → ᵞᵞ analysis, using the full 2016 dataset corresponding to an integrated luminosity of 35.9 fb-1, are shown.
Modern deep learning architectures, while highly successful, are characterized by substantial computational and memory demands due to their large number of parameters or the storing of activations. ...That is why it is hard to adapt a neural network to the constraints of hardware, especially at the edge. This paper presents an investigation into a novel approach for activation compression, which we term 'Projection-based compression on channels' or 'ProChan'. Our method involves interposing projection layers into a pretrained network around the nonlinearity, reducing the channel dimensionality through compression operations and then expanding it back. Our module is made to be then totally fused with the convolutions around it, guaranteeing no overhead, and maximum FLOPs reduction. We studied its absorption of the cost of quantization, to combine the two approaches for footprint reduction. Our findings indicate that the projections likely perform an 'adaptive stretching' operation on the feature space, enabling the preservation of essential information when constrained by dimensional limitations. We also perform an ablation study on the different possible strategies for a stable and quick training, and analyse the interactions with different quantization paradigms, namely PACT for activations and post-training quantization (PTQ) methods for weights.
Pre-training on an upstream task is widely used in deep learning to boost performance of downstream tasks. Recent studies analyzed pre-training with large datasets and large deep neural network ...architectures. However, pre-training is very useful in practice when downstream tasks have scarce data and are trained under computational constraints. To assess pre-training performance in this setting, we train different deep architectures with 1M parameters. We create different subsets of ImageNet to study the influence of upstream dataset in detail by varying the total size, but also the ratio between number of classes and samples per class for a constant total size. Then, we use the resulting models in transfer toward six diversified downstream tasks using linear probing and full fine tuning for downstream training. Experimental results confirm previous ones regarding performance saturation in downstream tasks, but we find that saturation occurs faster for compact deep architectures. The use of different ImageNet subsets leads to globally similar performance when enough data is included, regardless of the dataset structure. The comparison of downstream training strategies shows that linear probing can be competitive, particularly for few-shot settings. This is at odds with previous reports, which assert the superiority of full fine tuning. Finally, we observe that the type of deep architecture has a significant effect on results, but that their relative performance varies depending on the downstream training strategy.
Normalizing flows are generative models that show poor performance on out-of-distribution (OOD) detection tasks with a likelihood-based test. In this study we focus on the "approximate mass" metric. ...We show that while it improves OOD detection performance, it has limitations under a maximum likelihood training. To solve this limitation we modify the training objective by incorporating the approximate mass. It smooths the learnt distribution in the vicinity of training in-distribution data. We measure an average of 97.6% AUROC in our experiments on different benchmarks, showing an improvement of 16% with respect to the best baseline we tested against.
Purpose. The main objective of this paper is (і) to determinate the economic loss due to crop productivity loss caused by soil erosion in Ukraine, and (іі) to present the results of the econometric ...modeling of soil erosion impact on the efficiency crop production at the regional and district level.
Methodology / approach. This study uses the following methods: expert assessments and monographic (for the assessment of economic losses due to crop productivity loss from spreading soil erosion); graphical (for building three-dimensional graphs); econometric modeling (to develop a mathematical model of the dependence of the gross crop production and income from sales per 100 hectares from the share of eroded arable land in its total area and production costs in crop industry per 100 hectares); abstract-and-logical (for generalization of the research results). To solve the assigned tasks, linear and quadratic econometric models (production functions) were developed using a dataset (і) from 168 observations (on the example of Ukrainian regions for 2010–2016) and (ii) from 189 observations (on the example of districts of Kharkiv region for 2010–2016). This study was conducted in order to test the hypothesis that the increase in the area of eroded arable land has a negative effect on the gross output of crop production.
Results. Our expert assessment of economic losses due to crop productivity loss from spread of soil erosion on agricultural land in Ukraine is 224 mln USD. The obtained results confirm the hypothesis about the negative relationship between gross crop output and the level of land erosion. The obtained data confirm that an increase in the area of eroded arable land by 1 % leads to a decrease in the gross output of crop production by 0.20 % per 100 hectares of agricultural land in total, and in the third group of the studied subjects (the share of eroded arable land in their total area is more than 50 %) – by 0.61 %, respectively.
Originality / scientific novelty. For the first time, linear and nonlinear (quadratic) econometric models were developed, which made it possible to carry out quantitative assessment of the impact of the soil erosion and the financial support (production costs in crop industry) per hectare on the formation of the financial results (gross crop output and income) of business entities in Ukrainian agriculture. The provision on the economics of soil erosion was further developed in terms of expert assessment of losses from this type of degradation and confirmation of the effect of the economic law of diminishing returns, which should be taken into account when developing measures for sustainable land management.
Practical value / implications. The main results of the study can be used for the development, substantiation and implementation of soil protection measures for the sustainable use of agricultural land and/or to informed decision-making at different levels of management concerning restoration of eroded land.
The article outlines the prerequisites for implementing the principles of the circular economy in the activities of enterprises in the processing industry, and defines the peculiarities of the ...circular economy functioning. The absolute dynamics of environmental pollution were investigated, the average annual rate of increase in the volume of pollution, structural shifts in the use of waste by region, and the environmental friendliness of the products of the processing industry were analyzed. The methods of assessing structural changes make it possible to determine the nature of the changes that occurred within the hierarchy of priorities. On the other hand, methods of scenario analysis changes in the environmental pollution amount per unit of production of the processing industry were applied. The concept of closed ecological and economic cycle development in the processing industry is proposed, which combines modern practical experience of the circular economy implementation and economic and mathematical methods and models, allows to perform a quantitative assessment of the impact of the proposed measures on the environment and to adopt reasoned more balanced decisions. Recommendations for the implementation of the ecological and economic cycle in the processing industry of Ukraine were provided.
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