Yes / Bog bodies are among the best-known archaeological finds worldwide. Much of the work on these often extremely well-preserved human remains has focused on forensics, whereas the environmental setting of the finds has been largely overlooked. This applies to both the ‘physical’ and ‘cultural’ landscape and constitutes a significant problem since the vast spatial and temporal scales over which the practice appeared demonstrate that contextual assessments are of the utmost importance for our explanatory frameworks. In this article we develop best practice guidelines for the contextual analysis of bog bodies after having assessed the current state of research and presented the results of three recent case studies including the well-known finds of Lindow Man in the United Kingdom, Bjældskovdal (Tollund Man and Elling Woman) in Denmark, and Yde Girl in the Netherlands. Three spatial and chronological scales are distinguished and linked to specific research questions and methods. This provides a basis for further discussion and a starting point for developing approaches to bog body finds and future discoveries, while facilitating and optimising the re-analysis of previous studies, making it possible to compare deposition sites across time and space. / The Home Turf Project of Wageningen University and Research Centre, financed by the Dutch Organisation for Scientific Research (NWO Vidi Project, no. 276-60-003).

This thesis addresses the design of distributed scalar quantizers (DSQs) for two sensors, tailored to maximize the classification accuracy for a pre-trained binary linear classifier at the central node, diverging from traditional designs that prioritize data reconstruction quality. The first contribution of this thesis is the development of efficient globally optimal DSQ design algorithms for two correlated discrete sources when the quantizer cells are assumed to be convex. First, it is shown that the problem is equivalent to a minimum weight path problem (with certain constraints) in a weighted directed acyclic graph. The latter problem can be solved using dynamic programming with O(K_1K_2M^4) computational complexity, where Ki, is the number of cells for the quantizer of source i, i = 1, 2, and M is the size of the union of the sources’ alphabets. Additionally, it is proved that the dynamic programming algorithm can be expedited by a factor of M by exploiting the so called Monge property, for scenarios where the pre-trained classifier is the optimal classifier for the unquantized sources. Next, the design of so-called staggered DSQs (SDSQs) is addressed, i.e., DSQ’s with K_1 = K_2 = K and with the thresholds of the two quantizers being interleaved. First, a faster dynamic programming algorithm with only O(KM^2) time complexity is devised for the design of the SDSQ that minimizes an upperbound on the classification error. This sped up is obtained by simplifying the graph model for the problem. Moreover, it is shown that this algorithm can also be further accelerated by a factor of M when the pre-trained linear classifier is the optimal classifier. Furthermore, some theoretical results are derived that provide support to imposing the above constraints to the DSQ design problem in the case when the pre-trained classifier is optimal. First, it is shown that when the sources (discrete or continuous) satisfy a certain symmetry property, the SDSQ that minimizes the modified cost also minimizes the original cost within the class of DSQs without the staggerness constraint. For continuous sources, it is also shown that the SDSQ that minimizes the modified cost also minimizes the original cost and all quantizer thresholds are distinct, even if the sources do not satisfy the aforementioned symmetry condition. The latter result implies that DSQs with identical encoders are not optimal even when the sources has the same marginal distribution, a fact which is proved here for the first time, up to our knowledge. The last (but not least) contribution of this thesis resides in leveraging the aforementioned results to obtain efficient globally optimal solution algorithms for the problem of decentralized detection under the probability of error criterion of two discrete vector sources that are conditionally independent given any class label. The previously known globally optimal solution has O(N^(K_1+K_2+1)) time complexity, where N is the size of the union of the alphabets of the two sources. We show that by applying an appropriate transformation to each vector source, the problem reduces to the problem of designing the optimal DSQ with convex cells in the transformed scalar domain for a scenario where the pre-trained linear classifier is the optimal classifier. We conclude that the problem can be solved by a much faster algorithm with only O(K_1K_2N^3) time complexity. Similarly, for the case of equal quantizer rates, the problem can be solved in O(KN) operations if the sources satisfy an additional symmetry condition. Furthermore, our results prove the conjecture that for continuous sources, imposing the constraint that the encoders be identical precludes optimality, even when the marginal distributions of the sources are the same. / Thesis / Doctor of Philosophy (PhD)

The need for research instruments adaptable to culturally diverse populations has grown with globalization and digital connectivity. Ensuring measurement invariance (MI) is crucial for generating accurate and comparable scores, especially in comparative studies. Traditional approaches like Multi-Group Confirmatory Factor Analysis (MG-CFA) often involve intricate procedures and can become unwieldy when adjustments for partial invariance are needed. The Alignment-within-CFA (AwC) method emerged as a promising alternative, designed to approximate group-specific factors and produce latent variables with uniform metrics. This study rigorously compares the AwC method and traditional MG-CFA across moderate numbers of groups (3, 4, and 5) under various conditions of noninvariance and sample sizes. By employing Monte Carlo simulations, the study controls study variables and explores a wide range of hypothetical scenarios, enhancing the precision and reliability of MI testing. The findings indicate that the AwC method is similar to or superior to the step-wise partial invariance approach, offering accurate and consistent results in varied scenarios. Specifically, the study examines the conditions under which AwC outperforms traditional MG-CFA and investigates the impact of factors such as different types of invariance, number of groups, and sample size on bias and model fit. This research provides deeper insights into the strengths and limitations of each method, guiding researchers in selecting the most appropriate approach for their specific contexts. The results support the use of the AwC method in scenarios where minimizing bias and error in parameter estimates is critical, paving the way for more streamlined and effective research amidst increasing global diversity.

This dissertation documents the results of two related efforts. Firstly, a model of nucleon-nucleon (NN) interactions is developed based on scalar field theory. Secondly, the relativistic 2-body Bethe-Salpeter equation (BSE) is generalized to handle inelastic processes in the ladder approximation. Scalar field theory describes the behavior of scalar particles, particles with spin 0. In the present work scalar field theory is used to describe NN interactions mediated by pion exchange. The scalar theory is applied to nucleons despite the fact that nucleons are fermions, spin 1/2 particles best described by fourcomponent Dirac spinor fields. Nevertheless, the scalar theory is shown to give a good fit to experiment for the total cross sections for several reactions [1]. The results are consistent with more elaborate spinor models involving one boson exchange (OBE). The results indicate that the spin and isospin of nucleons can to some extent be ignored under certain conditions. Being able to ignore spin and isospin greatly reduces the complexity of the model. A limitation of the scalar theory is that it does not distinguish between particle and anti-particle. Consequently one must decide how to interpret the s-channel diagrams generated by the theory, diagrams which involve particle creation and annihilation. The issue is resolved by extending the scalar theory to include electric charge, and formulating NN interactions in terms of complex scalar fields, which are able to describe both particles and anti-particles. A generalized Bethe-Salpeter equation (GBSE) is developed to handle inelastic processes in the ladder approximation. The GBSE, formulated using the scalar theory, is new, and introduces a systematic method for analyzing families of coupled reactions. A formalism is developed centered around the amplitude matrix M' defined for a given Lagrangian. M' gives the amplitudes of a family of reactions that arise from the Lagrangian. The formalism demonstrates how these amplitudes, to 2nd order, segregate into independent groups of coupled BSE's. The GBSE formalism is applied to the coupled BSE (CBSE) of Faassen and Tjon (FT) [2] for the reaction N+N->N+Delta, showing that the CBSE is missing a coupling channel, and in the expansion, under counts ladder diagrams. A proof is given of the equivalence of the series of ladder diagrams generated by M' and the S-matrix. A section on future work discusses several projects for further development and application of the GBSE.

The objective is to contribute to several issues regarding the traditional view of the local structure of passive scalar fields: (1) probability density function (PDF) of the scalar concentration and scalar gradient, (2) the scalar power spectrum, (3) the structure functions, and (4) correlation functions and multi-point correlators. In addition, the research provides a geometric description of two-dimensional transects of the passive scalar iso-surfaces using the tools of fractal geometry. The local structure is analyzed as a function of large-scale anisotropy, intermittency factor, Reynolds number, and initial condition of the scalar injection. Experiments were performed in the bed boundary layer produced by a uniform depth open channel flow of water in a tilting flume for Re_lamda = 63, 94, and 120. A small nozzle iso-kinetically delivers a passive scalar of high Schmidt number ( Sc = 1000) at mid-depth to generate the turbulent scalar field. Three nozzle diameters are used to study the effects of the injection length scale. High-resolution planar laser induced fluorescence (PLIF) technique is used to measure the scalar field. The local structure far from isotropic and is influenced even at the smallest scales by large-scale anisotropy, initial injection length scale and the Reynolds number of the flow. The PDF of the scalar fluctuations is non-Gaussian and dependent on large-scale anisotropy. The PDF of scalar gradients show the influence of large-scale anisotropy on the structure at the smallest scales. The spectrum of the scalar field deviates from the in the inertial convection regime and is dependent on large-scale anisotropy, external intermittency, and low Reynolds number. There is no evidence of Batchelors k^-1 scaling law. The scaling exponents of the even-ordered structure functions appear to be inversely correlated with the kurtosis of the scalar fluctuations. The fractal geometry of the two dimensional transects of passive scalar iso-surfaces is scale dependent. The fractal dimension is 1.0 at the smallest length scale and increases in a universal manner in the viscous-convective regime. The coverage length underestimate reflects this universal behavior with practical significance. The lacunarity function shows that the instantaneous scalar field is most in-homogenous around the Kolmogorov scale.

安全多方計算是資訊安全研究裡的一個重要主題，其概念為多方在不洩漏各自私有資訊下能一起完成某種函式的計算。在安全多方計算研究領域裡，有一種作法是以scalar product來當作計算的基礎演算邏輯單元，重而建構其他更複雜的安全多方計算。本論文首先針對scalar product發展一套平行性實作架構，藉此我們再實作出多個不同演算法之comparison計算，其中包含了循序演算法以及平行演算法。我們透過實驗來找出適當的平行計算基礎架構與影響執行時間效能的主要因子，並以執行時間效能上的分析來推導相關時間公式。由上述實證研究我們對於不同演算法之comparison計算來作執行時間效能的預測，從實驗結果可以得知我們推導出來之時間公式極為準確，希望能給予使用者在執行comparison計算有所考量，使其在不同執行環境執行comparison計算能有最佳的執行時間效能。 / Loosely speaking, secure multi-party computation (SMC) involves computing functions with inputs from two or more parties in a distributed network while ensuring that no additional information, other than what can be inferred from each participant’s input and output, is revealed to parties not privy to that information. This thesis concerns the parallel implementation of SMC using a scalar-product (SP) based approach. In this approach, SP is considered as the basic building block for constructing more complex SMC. My thesis first develops a concurrent architecture for implementing two-party scalar product computation. Then it implements several algorithms of secure comparison. Finally, a series of experiments are conducted to collect performance statistics for building time functions that can predict the execution time of comparison computation based on that of the scalar product and other parameters, such as CPU core numbers. From the experimental results, we find that these time functions are very accurate. Hence we argue that these time functions can assist users to obtain the better runtime performance for comparison protocols under their specific execution environments.

The role of scalar mesons in radiative vector meson decays is investigated. The effects of scalar-isoscalar f_{0}(980) and scalar-isovector a_{0}(980) mesons are studied in the mechanism of the radiative Phi-&gt / pi{+}pi{-}gamma and phi-&gt / pi{0}eta gamma decays, respectively. A phenomenological approach is used to study the radiative phi-&gt / pi{+}p{-}gamma decay by considering the contributions of sigma-meson, rho-meson and f_{0}-meson. The interference effects between different contributions are analyzed and the branching ratio for this decay is calculated. The radiative phi-&gt / pi{0}eta gamma decay is studied within the framework of a phenomenological approach in which the contributions of rho-meson, chiral loop and a_{0}-meson are considered. The interference effects between different contributions are examined and the coupling constants g_{phi a_{0} gamma} and g_{a_{0}K{+}K{-}} are estimated using the experimental branching ratio for the phi-&gt / pi{0}eta gamma decay. Furthermore, the radiative rho{0}pi{+}pi{-}gamma$ and rho{0}-&gt / pi{0}pi{0}gamma decays are studied to investigate the role of scalar-isoscalar sigma-meson. The branching ratios of the rho{0}-&gt / pi{+}pi{-}gamma and rho{0}-&gt / pi{0}pi{0}gamma decays are calculated using a phenomenological approach by adding to the amplitude calculated within the framework of chiral perturbation theory and vector meson dominance the amplitude of sigma-meson intermediate state. In all the decays studied the scalar meson intermediate states make important contributions to the overall amplitude.

No description available.

<p>The properties of neutron stars and black holes are investigated within a class of alternative theories of gravity known as Scalar-Tensor theories, which extend General Relativity by introducing additional light scalar fields to mediate the gravitational interaction.</p> <p>It has been known since 1993 that neutron stars in certain Scalar-Tensor theories may undergo ‘scalarization’ phase transitions. The Weak Central Coupling (WCC) expansion is introduced for the purpose of describing scalarization in a perturbative manner, and the leading-order WCC coefficients are calculated analytically for constant-density stars. Such stars are found to scalarize, and the critical value of the quadratic scalar-matter coupling parameter β_s = −4.329 for the phase transition is found to be similar to that of more realistic neutron star models.</p> <p>The influence of cosmological and galactic effects on the structure of an otherwise isolated black hole in Scalar-Tensor gravity may be described by incorporating the Miracle Hair Growth Formula discovered by Jacobson in 1999, a perturbative black hole solution with scalar hair induced by time-dependent boundary conditions at spatial infinity. It is found that a double-black-hole binary (DBHB) subject to these boundary conditions is inadequately described by the Eardley Lagrangian and emits scalar dipole radiation.</p> <p>Combining this result with the absence of observable dipole radiation from quasar OJ287 (whose quasi-periodic ‘outbursts’ are consistent with the predictions of a general-relativistic DBHB model at the 6% level) yields the bound |φ/Mpl| < (16 days)^-1 on the cosmological time variation of canonically-normalized light (m < 10⁻²³ eV) scalar fields at redshift z ∼ 0.3.</p> / Doctor of Philosophy (PhD)

In this study we highlight the influence of mean dilatation and mean density gradient on the Reynolds stress modeling of compressible, heat-releasing and supercritical turbulent flows.Firstly, the modeling of the rapid pressure-strain correlation has been extended to self-consistently account for the influence of mean dilatation.Secondly, an algebraic model for the turbulent density flux has been developed and coupled to the tensor equationfor Reynolds stress anisotropy via a 'local mean acceleration',a generalization of the buoyancy force. We applied the resulting differential Reynolds stress model (DRSM) and the corresponding explicit algebraic Reynolds stress model (EARSM) to homogeneously sheared and compressed or expanded two-dimensional mean flows. Both formulations have shown that our model preserves the realizability of the turbulence, meaning that the Reynolds stresses do not attain unphysical values, unlike earlier approaches. Comparison with rapid distortion theory (RDT) demonstrated that the DRSM captures the essentials of the transient behaviour of the diagonal anisotropies and gives good predictions of the turbulence kinetic energy. A general three-dimensional solution to the coupled EARSM  has been formulated. In the case of turbulent flow in de Laval nozzle we investigated the influence of compressibility effects and demonstrated that the different calibrations lead to different turbulence regimes but with retained realizability. We calibrated our EARSM against a DNS of combustion in a wall-jet flow. Correct predictions of turbulent density fluxes have been achieved and essential features of the anisotropy behaviour have been captured.The proposed calibration keeps the model free of singularities for the cases studied. In addition,  we have applied the EARSM to the investigation of supercritical carbon dioxide flow in an annulus. The model correctly captured mean enthalpy, temperature and density as well as the turbulence shear stress. Hence, we consider the model as a useful tool for the analysis of a wide range of compressible flows with large density variation. / <p>QC 20160314</p>