No description available.

Meta-analysis is a tool used to combine the results from multiple studies into one comprehensive analysis. First developed in the 1970s, meta-analysis is a major statistical method in academic, medical, business, and industrial research. There are three traditional ways in which a meta-analysis is conducted: fixed or random effects, and using an empirical Bayesian approach. Derivations for conducting meta-analysis on correlations in the industrial psychology and organizational behavior (OB) discipline were reviewed by Hunter and Schmidt (2004). In this approach, Hunter and Schmidt propose an empirical Bayesian analysis where the results from previous studies are used as a prior. This approach is still widely used in OB despite recent advances in Bayesian methodology. This paper presents the results of a hierarchical Bayesian model for conducting meta-analysis of correlations and then compares these results to a traditional Hunter-Schmidt analysis conducted by Judge et al. (2001). In our approach we treat the correlations from previous studies as a likelihood, and present a prior distribution for correlations.

<p>This dissertation presents precision measurements of top quark polarizations and top quark pair spin correlations, which probe the independent coefficients of the top-spin components of the top quark pair production density matrix, targeting all channels (ee, eµ,  µµ) of the top quark pair dileptonic decay mode with final states containing two oppositely charged leptons, and using 137.7 fb<strong>⁻¹</strong> of data recorded by the CMS experiment at the LHC with 13 TeV center-of-mass energy, during 2016, 2017, and 2018.</p> <p>All measured observables are corrected for detector efficiencies, acceptances, and migrations, unfolded to parton-level, and extrapolated to the full phase space using a regularized unfolding procedure.</p> <p>Spin-density coefficients are extracted from the unfolded distributions and compared to theoretical predictions and predictions from Monte Carlo simulations with next-to-leading-order matrix element accuracy interfaced with parton-shower algorithms.</p> <p>The measurements are performed both in the full phase-space and differentially as a function of top quark pair invariant mass.</p> <p>The measured coefficients showed decent agreement with the MC predictions, and better agreement when compared to QCD perturbative calculations for top quark pair production at NLO with electroweak corrections, and the measurement precision for one-dimensional normalized unfolded cross-sections and extracted coefficients were improved by as much as a factor of two compared to previous measurements.</p>

In the Canadian Arctic, ship traffic has been increasing at the same time as sea ice has been declining over the past decade-plus. The decrease in sea ice has been associated with trends in warm weather and atmospheric conditions in the summer seasons, which are expected to continue. Thus, it is anticipated that ship traffic will also continue to grow, as areas in the Arctic, including the Northwest Passage (NWP) and Northern Sea Route (NSR) experience less and less sea ice. The appeal of the opening of these major Arctic shipping routes, is that these routes are shorter in distance for commercial ships on international voyages in comparison to traditional routes that travel through the Panama and Suez Canals. Assuming safe and smooth sailing a shorter route can be beneficial monetarily for commercial shipping companies and as a result for other economic sectors reliant on the efficient shipment of goods. However, a major concern associated with the anticipated increase in Arctic ship traffic is the potential for an increase in the number and severity of maritime navigational related accidents. Thus, the overall aim of this thesis is to quantify recent historic links between ship traffic, sea ice, ship accidents, and accident rates within the Canadian Arctic as well as the global Arctic. There are three specific objectives including to: 1. Conduct a comparative statistical analysis between two ship traffic databases (NORDREG and AIS) within the Canadian Arctic to evaluate datasets strengths and weaknesses; 2. Use the best available data (see objective 1) to examine the statistical associations and trends for ship traffic, ship accidents, accident rates, and sea-ice extent within the Canadian Arctic during the shipping-season from 1990 to 2019; and 3. Derive and compare recent ship traffic accident rates to determine if statistical trends from 2012 to 2019 exist for ships across the global Arctic. Results of the study show that both NORDREG and AIS data is useful in understanding shipping traffic trends in Arctic Canada over time and that each dataset is effective depending on the temporal period of interest (Objective 1). NORDREG data is most effective for identifying ship positioning before 2012 (+106,811 more nm sailed per matched unique vessels and +9 overall unique vessels from NORDREG) and from 2012 onwards AIS is more accurate, highlighted by the year of 2018 (+84,149 more nm sailed and +169 unique vessels from AIS). Using available data sources from 1990 to 2019, it was revealed that although commercial and non-commercial ship traffic is increasing across in Arctic Canada, the total number of accidents and overall accident rate for commercial vessels has declined, whereas they have increased for non-commercial ships (Objective 2). There are significant positive trends in overall ship traffic for all ship types (+9,275 nm yr⁻¹), commercial ships (+5,011 nm yr⁻¹) and non-commercial ships (+4,658 nm yr⁻¹). Whereas there have been significant negative trends in ship accidents for commercial ships (-0.06 accidents yr⁻¹), ship accident rates, for all ship types (-6.31E-07 accidents/nm yr⁻¹). Sea ice extent at the monthly level during the shipping season has been significantly decreasing (-3,193 km² mo⁻¹). Results also indicate that there are significant negative correlations between monthly ship traffic and sea ice extent, for all ship types (-0.50), commercial ships (-0.49), and non-commercial ships (-0.48). At the global scale, ship traffic is increasing while ship accident rates are decreasing (Objective 3). For the global Arctic there are positive statistically significant trends for all ship traffic (+2.655 million nm yr⁻¹), commercial ships (+1.598 million nm yr⁻¹), and non-commercial ships (+1.446 million nm yr⁻¹); where there are statistically significant annual decreases in ship accident rates for all ships (-3.64E-07 ship accidents/nm yr⁻¹), commercial ships (-9.39E-07 ship accidents/nm yr⁻¹), and non-commercial ships (-1.19E-07 ship accidents/nm yr⁻¹). At the country level, ship traffic associated to Russia, Norway, and Iceland contributes the most to global increase for both commercial and non-commercial ships. Norway has the largest statistically significant negative trend for all ship and commercial ship accident rates. Future research should focus around expanding on the analytical approach taken for objective 3, as more years of AIS data become available, as currently, the focus is on a shorter time-period (2012 to 2019). Given that incident rates are low globally, for high impacts (i.e., large spills), working with a long time series allows for considering more incidents. It would also be beneficial to perform an analysis that determines if there are statistical associations between yearly accident rates and sea ice extent in the global Arctic, as well as for each country within the Arctic. This information can help to answer questions around ship safety in the global Arctic, specifically: (a) Has the shipping become safer (e.g., less accidents per distance sailed) for the global Arctic and the countries within the Arctic? (b) Are there statistical associations between sea ice extent and accident rates within the global Arctic and the countries within the Arctic? (c) Are there countries associated with a higher incident rate compared to others? This information would help target measures to specific country ships that may be less safe for navigation.

In a celebrated series of experimental observations, starling flocks have been shown to be characterized by scale-free, long-ranged spatial correlations in their velocity fluctuations. While this is expected for velocity orientation correlations on the basis of simple symmetry-breaking arguments, the same scaling-free behaviour for speed (i.e. the absolute value of birds’ velocity) correlations cannot be explained by the same symmetry-based argument. Possible explanations so far put forward required the implicit or explicit fine-tuning of a speed control parameter. In this work we explore a different possibility, investigating the effects of the experimental discrete temporal sampling of individual bird trajectories. We argue that observed velocity may well be a time coarse-grained observable, that is, the sum over many faster course corrections taken by the bird. A simple argument shows such a time coarse-grained speed to be linked with the squared fluctuations of (soft modes) transversal velocities, which may thus acquire a long-range correlation. Our idea is numerically tested by measuring spatial correlations between coarse-grained speeds in the on-lattice equilibrium XY model and the off-lattice out-of-equilibrium Vicsek model in two dimensions. Saturation of the speed correlation length is found in the equilibrium XY model, while in the non-equilibrium Vicsek model ordered symmetry-broken phase shows scale-free behaviour with a correlation length ξ is found to be proportional to system size L. We conclude that in non-equilibrium flocking models, the temporal coarse-graining procedure is able to reproduce scale-free behaviour at system sizes which are relevant to the experimental observations. We believe that this mechanism might find applications beyond the case of starling flocks and perhaps be relevant for other experimental observations of collective motion.

During the casting of a concrete bridge deck, the temporary formwork is causing the underlying ground to deform if a shallow foundation solution is used. There are often demands on the maximum deformation of the superstructure when designing the foundation for the formwork.  To keep the deformations within the desired limits, several ground improvement methods like deep mixing columns or deep foundation methods like piling can be used. Permanent ground improvement methods are however expensive, and far from always needed. To reduce the need for unnecessary ground improvements, it is crucial to calculate the predicted deformations accurately during the design phase. The purpose of this thesis was to investigate how short-term deformations in clay under a formwork during bridge construction should be calculated more generally in future projects. Three different calculation models have here been used to calculate the ground deformations caused by the temporary formwork. A simple analytical calculation and two numerical calculations based on the Mohr Coulomb and Hardening Soil-Small constitutive models. The three calculation models were chosen based on their complexity. The analytical calculation model was the most idealised and the Hardening Soil-Small to be the most complex and most realistic model. Results show that the numerical calculation model Mohr Coulomb and the analytical calculation model gives the best results compared to the measured deformation. One of the most probable reasons for the result is that both of the models require a few input parameters that can easily be determined by well-known methods, such as triaxial-, routine- and CRS-tests. The more advanced Hardening soil small model requires many parameters to fully describe the behaviour of soil. Many of the parameters are hard to determine or seldom measured. Due to the larger uncertainties in the parameter selection compared with the other two models, the calculated deformation also contains larger uncertainties. / Vid gjutning av betongbrodäck kommer den underliggande marken att deformeras av den temporära formställningen, som tar upp lasterna medan betongen härdar. Det finns oftast krav på hur stora markdeformationerna maximalt får vara. För att hålla deformationerna inom gränserna kan diverse markförstärkningsmetoder, så som kalkcementpelare eller pålar, användas. Permanenta markförstärkningar är oftast väldigt dyra och inte alltid nödvändiga. Ett alternativ till att använda dyra markförstärkningar skulle kunna vara att beräkna den förutspådda deformationen med stor exakthet i projekteringsstadiet. Syftet med det här arbetet var att undersöka hur korttidsstätningar i lera vid en bronybyggnation ska beräknas mer generellt i framtida projekt.  I detta arbete har tre beräkningsmodeller använts för att beräkna markdeformationerna från den temporära formställningen. En enklare analytisk modell samt två numeriska beräkningsmodeller som baseras på Mohr Coulomb och Hardening Soil Small teorierna. De tre beräkningsmodellerna valdes utifrån deras komplexitet. Den analytiska beräkningen ansågs vara den mest förenklade modellen medan Hardening Soil-Small var den mest komplexa och realistiska modellen.   Resultatet visar att trots sin enkelhet så ger den numeriska beräkningsmodellen Mohr Coulomb och den analytiska beräkningen bäst resultat jämfört med de uppmätta deformationerna. En möjlig anledning till det goda resultatet är att modellerna endast kräver ett fåtal ingångsparametrar som kan bestämmas med hjälp av välkända fält- och laboratoriemetoder så som triaxialförsök, rutinlaboratorieförsök och CRS-försök. Den mer komplexa modellen Hardening Soil Small kräver flera ingångsparametrar för att kunna modellera jordens beteende. Många av parametrarna är svåra att bestämma då mätdata oftast saknas. Osäkerheterna i valet av ingångsparametrar för den mer komplexa hardening soil small modellen är större än de två andra studerade modellerna, vilekt även ger upphov till större osäkerheter i dem beräknade deformationerna.

Yes / This research article analyzed the self-preserving behaviour of wall-wake region of a circular pipe mounted horizontally over a flat rigid sand bed in a shallow flow in terms of mean velocity, RSS, and turbulence intensities. The study aims to investigate self-preservation using appropriate length and velocity scales.in addition to that wall-normal distributions of the third-order correlations along the streamwise direction in the wake region are analyzed. An ADV probe was used to record the three-dimensional instantaneous velocities for four different hydraulic and physical conditions corresponding to four cylinder Reynolds numbers. The results revealed that the streamwise velocity deficits, RSS deficits, and turbulence intensities deficits distributions displayed good collapse on a narrow band when they were non-dimensionalized by their respective maximum deficits. The wall-normal distance was non-dimensionalized by the half velocity profile width for velocity distributions, while the half RSS profile width was used in the case of the RSS deficits and turbulence intensities deficits distributions. The results indicate the self-preserving nature of streamwise velocity, RSS, and turbulence intensities in the wall-wake region of the pipe. The third-order correlations distributions indicate that sweep is the dominant bursting event in the near-bed zone. At the same time, ejection is the dominant bursting event in the region above the cylinder height.

Congestion is a world-wide problem in transportation. One major reason is random interruptions. The traffic network is inherently stochastic, and strong dependencies exist among traffic quantities, e.g., travel time, traffic speed, link volume. Information in stochastic networks can help with adaptive routing in terms of minimizing expected travel time or disutility. Routing in such networks is different from that in deterministic networks or when stochastic dependencies are not taken into account. This dissertation addresses the optimal routing problems, including the optimal a priori path problem and the optimal adaptive routing problem with different information scenarios, in stochastic and time-dependent networks with explicit consideration of the correlations between link travel time random variables. There are a number of studies in the literature addressing the optimal routing problems, but most of them ignore the correlations between link travel times. The consideration of the correlations makes the problem studied in this dissertation difficult, both conceptually and computationally. The optimal path finding problem in such networks is different from that in stochastic and time-dependent networks with no consideration of the correlations. This dissertation firstly provides an empirical study of the correlations between random link travel times and also verifies the importance of the consideration of the spatial and temporal correlations in estimating trip travel time and its reliability. It then shows that Bellman's principle of optimality or non-dominance is not valid due to the time-dependency and the correlations. A new property termed purity is introduced and an exact label-correcting algorithm is designed to solve the problem. With the fast advance of telecommunication technologies, real-time traffic information will soon become an integral part of travelers' route choice decision making. The study of optimal adaptive routing problems is thus timely and of great value. This dissertation studies the problems with a wide variety of information scenarios, including delayed global information, real-time local information, pre-trip global information, no online information, and trajectory information. It is shown that, for the first four partial information scenarios, Bellman's principle of optimality does not hold. A heuristic algorithm is developed and employed based on a set of necessary conditions for optimality. The same algorithm is showed to be exact for the perfect online information scenario. For optimal adaptive routing problem with trajectory information, this dissertation proves that, if the routing policy is defined in a similar way to other four information scenarios, i.e., the trajectory information is included in the state variable, Bellman's principle of optimality is valid. However, this definition results in a prohibitively large number of the states and the computation can hardly be carried out. The dissertation provides a recursive definition for the trajectory-adaptive routing policy, for which the information is not included in the state variable. In this way, the number of states is small, but Bellman's principle of optimality or non-dominance is invalid for a similar reason as in the optimal path problem. Again purity is introduced to the trajectory-adaptive routing policy and an exact algorithm is designed based on the concept of decreasing order of time.

The objective of the work was to establish strong correlations between midsole materials, biomechanics assessment and field test concerning running shoes and thus, for two crucial parameters: cushioning and ride.                A large range of mechanical testing (Shock tower, Compression, Dynamical Mechanical Analysis, Hardness) was carried out on EVA (Ethylene Vinyl Acetate) foam planks used in midsoles. Distinct sample sizes were needed according to the lab test and external machining was utilized to get appropriate specimens. Similar experiments have been led on prototypes finished shoes (Shock tower, Hardness) when it was feasible. The whole toolbox of current Salomon Footwear midsole formulations was so reviewed in detail. A phase of Biomechanics assessment of cushioning and ride was then undertaken with the help of a dozen of testers using sensors, procedures and data processing software. The field test was conducted at the same time to have the perception of the runners about several criteria once they worn the shoes in real condition.                Computational software were used to elaborate correlations matrices between determining parameters (finished shoes) and explicative ones (foams) while reducing the number of laboratory testing.  Prediction models for shoe performance anticipation were developed for the cushioning. Unfortunately, ride prediction model was not realized due to time and feasibility limitations. Shoe rebound resiliency and biomechanical parameters (Kurtosis and Power Spectral Density) proved to be strongly linked to the foam properties (Shock tower, Compression, Dynamical Mechanical Analysis). It could thus be forecast before making any shoe prototype. The reorganization of the Salomon Footwear toolbox has been started with the aim of finding one proper midsole for one proper application or runner practice. Established prediction models have been used to elaborate a cushioning index to sort the foam formulation according to their performance, density and price. Recommendations have been made for the choice of materials.

<p>Despite the unprecedented success achieved by Kohn-Sham density functional theory (KS-DFT) in the past few decades, the standard approximations used for the KS exchange-correlation functional typically lead to unacceptably large errors when applied to strongly-correlated electronic systems. Partition-DFT (P-DFT) is a formally exact reformulation of KS-DFT in which the ground-state density and energy of a system are obtained through self-consistent calculations on isolated fragments, with a partition energy introduced to account for the inter-fragment interactions. The unique advantage of this partitioning scheme lies in the fact that it adopts the electron density of fragments as the main variable, in place of the density of the entire system in KS-DFT, so that novel approximations can be constructed in terms of fragment properties. With a simple overlap approximation (OA) of the partition energy proposed for binary-partitioned systems, P-DFT is able to rectify the static correlation error caused by standard density functional approximations for strongly-correlated diatomic molecules. In this work, we first implement P-DFT on a one-dimensional (1D) real-space grid and calculate the ground-state energy and density of a series of 1D hydrogen chains using the local density approximation (LDA) as the density functional approximation for fragments. We then propose the generalized overlap approximation (GOA) and the corrected generalized overlap approximation (cGOA), which extends the applicability of OA to systems partitioned into more than two fragments. Combining LDA with cGOA leads to quantitatively correct dissociation curves of hydrogen chains. The static correlation error of LDA is suppressed by cGOA in the strongly-correlation regime when the calculations are performed in a spin-restricted manner, i.e., without the spin symmetry breaking. Additionally, GOA induces an improvement of the ground-state density upon LDA results, and hence helps P-DFT provide a better description of the density dimerization in hydrogen chains.</p>