Semiconductor manufacturers must ensure that chips conform to their specifications before they are shipped to customers. This is achieved by testing various parameters of a chip to determine whether it is defective or not. Separating defective chips from fault-free ones is relatively straightforward for functional or other Boolean tests that produce a go/no-go type of result. However, making this distinction is extremely challenging for parametric tests. Owing to continuous distributions of parameters, any pass/fail threshold results in yield loss and/or test escapes. The continuous advances in process technology, increased process variations and inaccurate fault models all make this even worse. The pass/fail thresholds for such tests are usually set using prior experience or by a combination of visual inspection and engineering judgment. Many chips have parameters that exceed certain thresholds but pass Boolean tests. Owing to the imperfect nature of tests, to determine whether these chips (called "outliers") are indeed defective is nontrivial. To avoid wasted investment in packaging or further testing it is important to screen defective chips early in a test flow. Moreover, if seemingly strange behavior of outlier chips can be explained with the help of certain process parameters or by correlating additional test data, such chips can be retained in the test flow before they are proved to be fatally flawed. In this research, we investigate several methods to identify true outliers (defective chips, or chips that lead to functional failure) from apparent outliers (seemingly defective, but fault-free chips). The outlier identification methods in this research primarily rely on wafer-level spatial correlation, but also use additional test parameters. These methods are evaluated and validated using industrial test data. The potential of these methods to reduce burn-in is discussed.

Semiconductor manufacturers must ensure that chips conform to their specifications before they are shipped to customers. This is achieved by testing various parameters of a chip to determine whether it is defective or not. Separating defective chips from fault-free ones is relatively straightforward for functional or other Boolean tests that produce a go/no-go type of result. However, making this distinction is extremely challenging for parametric tests. Owing to continuous distributions of parameters, any pass/fail threshold results in yield loss and/or test escapes. The continuous advances in process technology, increased process variations and inaccurate fault models all make this even worse. The pass/fail thresholds for such tests are usually set using prior experience or by a combination of visual inspection and engineering judgment. Many chips have parameters that exceed certain thresholds but pass Boolean tests. Owing to the imperfect nature of tests, to determine whether these chips (called "outliers") are indeed defective is nontrivial. To avoid wasted investment in packaging or further testing it is important to screen defective chips early in a test flow. Moreover, if seemingly strange behavior of outlier chips can be explained with the help of certain process parameters or by correlating additional test data, such chips can be retained in the test flow before they are proved to be fatally flawed. In this research, we investigate several methods to identify true outliers (defective chips, or chips that lead to functional failure) from apparent outliers (seemingly defective, but fault-free chips). The outlier identification methods in this research primarily rely on wafer-level spatial correlation, but also use additional test parameters. These methods are evaluated and validated using industrial test data. The potential of these methods to reduce burn-in is discussed.

Determining the emergent behaviour of a population from the interactions of its individuals is an ongoing challenge in the modelling of biological phenomena. Many classical models assume that the spatial location of each individual is independent of the locations of all other individuals. This mean-field assumption is not always realistic; in biological systems we frequently see clusters of individuals develop from uniform initial conditions. In this thesis, we explore situations in which the mean-field approximation is no longer valid for volume-excluding processes on a regular lattice. We provide methods which take into account the spatial correlations between lattice sites, thus more accurately reflecting the system's behaviour, and discuss methods which can provide information as to the validity of mean-field and other approximations.

Multiple-Input Multiple-Output (MIMO) communications systems using multiantenna arrays simultaneously during transmission and reception have generated significant interest in recent years. Theoretical work in the mid 1990?s showed the potential for significant capacity increases in wireless channels via spatial multiplexing with sparse antenna arrays and rich scattering environments. However, in reality the capacity is significantly reduced when the antennas are placed close together, or the scattering environment is sparse, causing the signals received by different antennas to become correlated, corresponding to a reduction of the effective number of sub-channels between transmit and receive antennas. By introducing the previously ignored spatial aspects, namely the antenna array geometry and the scattering environment, into a novel channel model new bounds and fundamental limitations to MIMO capacity are derived for spatially constrained, or spatially selective, channels. A theoretically derived capacity saturation point is shown to exist for spatially selective MIMO channels, at which there is no capacity growth with increasing numbers of antennas. Furthermore, it is shown that this saturation point is dependent on the shape, size and orientation of the spatial volumes containing the antenna arrays along with the properties of the scattering environment. This result leads to the definition of an intrinsic capacity between separate spatial volumes in a continuous scattering environment, which is an upper limit to communication between the volumes that can not be increased with increasing numbers of antennas within. It is shown that there exists a fundamental limit to the information theoretic capacity between two continuous volumes in space, where using antenna arrays is simply one choice of implementation of a more general spatial signal processing underlying all wireless communication systems.

Physical layer security (PLS) is a new paradigm aiming at securing communications between legitimate parties at the physical layer. Conventionally, achieving confidentiality in communication networks relies on cryptographic techniques such as public-key cryptography, secret-key distribution and symmetric encryption. Such techniques are deemed secure based on the assumption of limited computational abilities of a wiretapper. Given the relentless progress in computational capacities and the dynamic topology and proliferation of modern wireless networks, the relevance of the previous techniques in securing communications is more and more questionable and less and less reliable. In contrast to this paradigm, PLS does not assume a specific computational power at any eavesdropper, its premise to guarantee provable security via employing channel coding techniques at the physical layer exploiting the inherent randomness in most communication systems. In this dissertation, we investigate a particular aspect of PLS, which is secret-key agreement, also known as secret-sharing. In this setup, two legitimate parties try to distill a secret-key via the observation of correlated signals through a noisy wireless channel, in the presence of an eavesdropper who must be kept ignorant of the secret-key. Additionally, a noiseless public channel is made available to the legitimate parties to exchange public messages that are also accessible to the eavesdropper. Recall that key agreement is an important aspect toward realizing secure communications in the sense that the key can be used in a one-time pad scheme to send the confidential message. In the first part, our focus is on secret-sharing over Rayleigh fading quasi-static channels. We study the fundamental relationship relating the probability of error and a given target secret-key rate in the high power regime. This is characterized through the diversity multiplexing tradeoff (DMT) concept, that we define for our model and then characterize it. We show that the impact of the secrecy constraint is to reduce the effective number of transmit antennas by the number of antennas at the eavesdropper. Toward this characterization, we provide several schemes achieving the DMT and we highlight disparities between coding for the wiretap channel and coding for secret-key agreement. In the second part of the present work, we consider a fast-fading setting in which the wireless channels change during each channel use. We consider a correlated environment where transmit, legitimate receiver and eavesdropper antennas are correlated. We characterize the optimal strategy achieving the highest secret-key rate. We also identify the impact of correlation matrices and illustrate our analysis with various numerical results. Finally, we study the system from an energy-efficiency point of view and evaluate relevant metrics as the minimum energy required for sharing a secret-key bit and the wideband slope.

Wood products tend to have a very large variability resulting in over design of engineered products. A relatively new structural composite wood material, Parallel Strand Lumber (PSL) has been introduced with the expectation to reduce the inherent biological variation wood products tend to have between specimens and species. A probabilistic approach is being taken to model effective properties, strain, and strength of PSL. Biological variation of grain angle, effective properties, biological defects such as voids, strand dimensions, and constitutive species composing each PSL member were taken into account. Methods will be used to verify experimental results for the ultimate stress or maximum stress, modulus of elasticity, lengthwise variability, and stress-strain behavior of Parallel Strand Lumber made from southern yellow pine. Experimental compression data is measured from 64 A specimens with the dimensions 1.10 in x 1.10 in x 3.25 in and 162 B specimens with the dimensions 1.55 in x 1.55 in x 5.00 in. This data yields compression modulus of elasticity values of 1840 ksi with a standard deviation of 300 ksi for the A specimens and 1860 ksi with a standard deviation of 400 ksi for the B specimens. The ultimate stress at failure of the A specimens is 7.71 ksi with a standard deviation of 1.09 ksi and the ultimate stress at failure of the B specimens is 8.97 ksi with a standard deviation of 1.02 ksi. Experimental bending data is measured from 1 A specimen with the dimensions 5.25 in x 5.25 in x 192 in and 9 B specimens with the dimensions 1.55 in x 1.55 in x 96 in. These experiments yield edgewise modulus of elasticity values in bending of 1775 ksi with a standard deviation of 25 ksi for the A specimen and 1648 ksi with a standard deviation of 150 ksi for the B specimens.

Spontaneous parametric down-conversion (SPDC) is a nonlinear optical process in which an incident field known as the pump interacts with a nonlinear crystal to produce two output fields known as signal and idler. Due to the conservation of energy and momentum, these output fields are entangled in the temporal and spatial degrees of freedom. The gain, which represents the strength of the interaction, increases in direct proportion to the strength of the pump field. In the low-gain regime, the generated field is an entangled two-photon state. This regime continues to be routinely employed in fundamental quantum optics experiments and quantum technologies. In the high-gain regime, the generated field is a multiphoton entangled state known as a bright squeezed vacuum. The goal of this thesis is to theoretically and experimentally characterize the spatial correlations present in high-gain SPDC. In order to characterize the spatial correlations between the generated fields, we utilize the Schmidt decomposition formalism. In this study, we examine the evolution of the Schmidt modes and spectrum with increasing pump amplitude. Our work shows that the Schmidt modes expand marginally in size, and the Schmidt spectrum narrows with respect to increasing gain. The narrowing of the Schmidt spectrum, as quantified by a decrease in the Schmidt number, indicates a gradual decrease in spatial entanglement.

This is a thesis about the spatial distribution of willow warbler, nightingale, blackbird, robin and grey flycatcher in Svealand and Götaland, that is the southern third of Sweden. It explores the possibilities of using statistics to describe the distribution and variation of birds in a given region.The data was collected by observation of birds on sites called standard routes, with 25 kilometres between them. The standard routes are the points in a grid net placed upon the map of Sweden. The purpose of standard routes is to represent the birds in Sweden both geographic and biotopological.The thesis compare the results from kriging, variogram and four alternative poisson regressions. In the end I come up with the information provided by kriging and variogram and which poisson regression that bests estimates the population sizes of the birds at a given site with information about year, mean temperature from January to May and what kind of environment or habitat the site consist of.

abstract: 摘要 当前中国农村集体经济呈现出后劲不足、区域失衡等问题。在此背景下，如何破解集体经济发展困境、实现其从梯度到均衡的演进成为学术领域关注的热点。本文梳理总结了国内外集体经济的相关研究成果，阐述了主要涉及的基础概念、理论和方法模型；以2008~2015年无锡市滨湖区92个村为研究样本，分析了该区域集体经济的发展现状和演变进程；构建面板回归模型，探索了该区域集体经济发展的驱动因素与分布不平衡性；并从空间关联视角切入，探索了驱动因素的溢出效应；最后基于研究结果提出对策建议。主要结论如下： （1）2008~2015年，92个村的村级集体经济发展整体呈现上升趋势，但地区间的贫富差距明显；2008年、2011年和2015年92个村按村级集体经济总收入可划分为高、中、低3类，并且在不同时段，各等级间的村级集体单位会相互迁移；集体经济收入呈现明显的右偏分布，尖峰厚尾的特征显著。随着时间的推移，集体经济发展出现了“双峰趋同”的现象。 （2）普通面板回归显示，物质资本、经济工作能力、科技进步对于村级集体经济发展有正向的依次减弱的影响，人口数量的影响为负；面板分位数回归显示，随着分位数水平的提高，物质资本系数先上升、后下降再上升；经济工作能力系数逐渐减小；人口规模系数先下降后上升；科技进步系数波动上升。 （3）空间计量结果显示，各变量对于村级集体经济发展具有一定的溢出效应，其中，物质资本的溢出效应为正（不显著），经济工作能力的溢出效应为正（显著），人口因素的溢出效应为负（不显著），科技进步的溢出效应为正（显著）。 本文的创新之处在于使用较难获取的2008-2015年92个村面板数据进行回归，相比于截面数据，更准确地测度了各要素对集体经济的真实影响；将空间关联因素纳入研究视域，探究了村级集体经济驱动因素的空间溢出效应。 / Dissertation/Thesis / Doctoral Dissertation Business Administration 2019

Propagation-based key establishment is a physical layer method for generating encryption keys based on two radios observing a reciprocal propagation channel. This work explores the impact of mutual coupling when communicating nodes are equipped with multiple antennas, multipath richness in the propagation environment, and practical limitations caused by the nonreciprocal nature of RF circuits on key establishment. First, network theory is used to formulate a model of a realistic communication system which incorporates transmit sources and receive loads, impedance matching networks, low-noise amplifiers (LNAs), mutually coupled antenna arrays, and a passive eavesdropper. Afterwards, a detailed analysis is performed to quantify the impact of coupling, type of impedance matching network, and proximity of a multi-antenna eavesdropper on key rate metrics. Next, the degradation on key establishment caused by the radiocircuitry non-reciprocal contributions to the propagation channel is analyzed. A calibration technique based on total least square algorithm is used to overcome the non-reciprocity. Results demonstrate that the method is highly effective in removing the impact of non-reciprocal circuit contributions over a range of operational parameters. Lastly, for key establishment, the propagation conditions can cause the available key rate to be significantly different from the secure key rate which takes into account the presence of a passive eavesdropper. To study this in detail, a realistic multiple-input multiple-output (MIMO) propagation environment is modeled for two communicating radios and an eavesdropper. Afterwards different propagation conditions are assumed and results demonstrate that secure key rate converges to available key rate when K-factor is small and the eavesdropper is not located very close (< 2.5 wavelength) to one of the nodes.