916 research outputs found
STATISTICAL METHODS FOR ENVIRONMENTAL EXPOSURE DATA SUBJECT TO DETECTION LIMITS
In this dissertation, we develop unified and efficient nonparametric statistical methods for estimating and comparing environmental exposure distributions in presence of detection limits. In the first part, we propose a kernel-smoothed nonparametric estimator for the exposure distribution without imposing any independence assumption between the exposure level and detection limit. We show that the proposed estimator is consistent and asymptotically normal. Simulation studies demonstrate that the proposed estimator performs well in practical situations. A colon cancer study is provided for illustration. In the second part, we develop a class of test statistics to compare exposure distributions between two groups by using the integrated weighted difference in the kernel-smoothed estimator proposed in the first part. We study the conditions on the weight function such that the test statistics are stable, i.e. the asymptotic variances are finite. Simulation studies demonstrate that the proposed tests preserve type I errors regardless whether the distributions of the detection limit in the two groups differ or not and are more efficient than current methods in certain situations. A colon cancer study is provided for illustration. In the third part, we extend the estimation and testing methods developed in the part one and two to survey data by incorporating sampling weights. The results of several simulation studies are reported to demonstrate the performance of the proposed methods. The Jackknife method is utilized for the variance estimation to account for complex sample designs
Encoding and Decoding Narratives: Datafication and Alternative Access Models for Audiovisual Archives
Situated in the intersection of audiovisual archives, computational methods,
and immersive interactions, this work probes the increasingly important
accessibility issues from a two-fold approach. Firstly, the work proposes an
ontological data model to handle complex descriptors (metadata, feature
vectors, etc.) with regard to user interactions. Secondly, this work examines
text-to-video retrieval from an implementation perspective by proposing a
classifier-enhanced workflow to deal with complex and hybrid queries and a
training data augmentation workflow to improve performance. This work serves as
the foundation for experimenting with novel public-facing access models to
large audiovisual archivesComment: arXiv admin note: substantial text overlap with arXiv:2310.0582
Mantle flow systems associated with slab subduction and absolute plate motion in Alaska constrained by shear wave splitting analyses
Alaska has long been recognized as a geologically complex region with a sharp contrast in tectonic activity between southern and northern Alaska. While the former is characterized by the subduction of the geometrically varying Pacific-Yakutat plate beneath the North American plate, the latter has a mostly stable cratonic setting. To investigate the mantle flow fields beneath Alaska and understand the influence of the subduction process on regional mantle dynamics, a total of 2790 pairs of well-defined teleseismic shear wave splitting (SWS) measurements recorded from 379 stations are obtained and analyzed. In addition, 247 pairs of SWS results from local earthquake events are measured to isolate contribution of the mantle wedge to the teleseismic shear wave splitting. We obtain well-defined two-layered anisotropy models in three areas in southern Alaska. The observations revealed several mantle flow fields, including trench- parallel flow beneath the Pacific slab, trench-normal flow beneath the flat Yakutat slab, toroidal flow around the Pacific-Yakutat slab edge, absolute plate motion-parallel flow in the stable cratonic area, and deflected flow around the deep continental keel in northern and possibly western Alaska. The presence of a slab edge and conflicting conclusions from previous shear wave splitting studies motivated us for an in-depth analysis of the splitting measurements in southcentral Alaska. The results indicate that the sub-slab flow, which is driven by slab roll-back, may separate into two branches at the edge: One flows anticlockwise to the wedge, and the other continues flowing to the east of the study area --Abstract, page iv
Climate Change and Residential Energy Use in Europe : Assessing Future Energy Demands and Renewable Generation Potentials
In recent years, climate change and the corresponding expected extreme weather conditions have been widelyrecognized as potential problems. The construction industry is taking various actions to achieve sustainabledevelopment, implement energy conservation strategies, and provide climate change mitigation. In addition tomitigation, it is crucial to adapt to climate change, and to investigate the possible risks and limitations of mitigationstrategies. Although the importance of climate change adaptation is well-understood, there are still challenges inunderstanding and modeling the impacts of climate change, and the consequent risks and extremes.This licentiate dissertation aims to assess the impact of climate change on the building energy performance andindoor thermal comfort in 38 major European cities distributed in five difference climate zones. In addition, this studyalso investigates the potential of renewable energy generation considering solar PV and wind energy generations.To do this, an ensemble of multiple future climate scenarios with high temporal and spatial resolutions have beenused in this work, enabling us to account for climate variations and extreme events. A set of future climate big datagenerated by RCA4 regional climate model (RCM) were used. In total, 13 future climate scenarios covering fiveglobal climate models (GCMs) and three representative concentration pathways (RCP 2.6, RCP 4.5 and RCP 8.5)were used for the 90-year span of 2010-2099, divided into three 30-year periods (2010-2039, 2039-2069 and 2069-2099).Results show that extreme long and short-term climate events can cause significant changes in energy demand,particularly peak loads during extreme events. This work provided more insights into the importance of consideringboth long- and short-term variations of climate, including extreme events, when assessing future energy solutionsand the energy performances of building stocks.The availability of fine temporal and spatial resolution climate datais crucial for assessing the plausible energy demands of buildings; however, it is important consider climateuncertainties, multiple scenarios, and extreme climate events.Finally, the database of results for each city andclimate zone allows decision makers and designers to count for future climate uncertainties in the early stages ofbuilding design
Noise effects on purity and quantum entanglement in terms of physical implementability
Quantum decoherence due to imperfect manipulation of quantum devices is a key
issue in the noisy intermediate-scale quantum (NISQ) era. Standard analyses in
quantum information and quantum computation use error rates to parameterize
quantum noise channels. However, there is no explicit relation between the
decoherence effect induced by a noise channel and its error rate. In this work,
we propose to characterize the decoherence effect of a noise channel by the
physical implementability of its inverse, which is a universal parameter
quantifying the difficulty to simulate the noise inverse with accessible
quantum channels. We establish two concise inequalities connecting the decrease
of the state purity and logarithmic negativity after a noise channel to the
physical implementability of the noise inverse. Our results are numerically
demonstrated on several commonly adopted two-qubit noise models.Comment: 16 pages, 1 figur
Latent Wander: an Alternative Interface for Interactive and Serendipitous Discovery of Large AV Archives
Audiovisual (AV) archives are invaluable for holistically preserving the
past. Unlike other forms, AV archives can be difficult to explore. This is not
only because of its complex modality and sheer volume but also the lack of
appropriate interfaces beyond keyword search. The recent rise in text-to-video
retrieval tasks in computer science opens the gate to accessing AV content more
naturally and semantically, able to map natural language descriptive sentences
to matching videos. However, applications of this model are rarely seen. The
contribution of this work is threefold. First, working with RTS (T\'el\'evision
Suisse Romande), we identified the key blockers in a real archive for
implementing such models. We built a functioning pipeline for encoding raw
archive videos to the text-to-video feature vectors. Second, we designed and
verified a method to encode and retrieve videos using emotionally abundant
descriptions not supported in the original model. Third, we proposed an initial
prototype for immersive and interactive exploration of AV archives in a latent
space based on the previously mentioned encoding of videos
A case study of the novel Siddhartha from the perspective of intertextuality
This article argues for intertextuality as a critical and analytic method for reading literary texts. To develop this argument first a critique on structuralism and deconstruction has been presented. Secondly, it has been pointed out that both these theories are not adequate because both of them take their departure from a linguistic theory of Ferdinand de Saussure which is not sufficient to understand the nature of text, author and the society in which they take place. It has been argued on the contrary that the idea of dialogicality proposed by Mikhail Bakhtin does seem helping us better to resolve the issues which cannot be tackled by both structuralism and deconstruction. The idea of dialogicality gives birth to intertextuality which, as a suggestion, should be adopted for literary and critical practices. In the end part of this article a case study of the novel Siddhartha by Hermann Hesse, a German writer, has been presented to make the idea of intertextuality clear and forceful.
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