Conduction in thin InSb films

Imperial Users onl

Automatic generation of named entity taggers leveraging parallel corpora

The lack of hand curated data is a major impediment to developing statistical semantic processors for many of the world languages. A major issue of semantic processors in Nat- ural Language Processing (NLP) is that they require manually annotated data to perform accurately. Our work aims to address this issue by leveraging existing annotations and semantic processors from multiple source languages by projecting their annotations via statistical word alignments traditionally used in Machine Translation. Taking the Named Entity Recognition (NER) task as a use case of semantic processing, this work presents a method to automatically induce Named Entity taggers using parallel data, without any manual intervention. Our method leverages existing semantic processors and annotations to overcome the lack of annotation data for a given language. The intuition is to transfer or project semantic annotations, from multiple sources to a target language, by statistical word alignment methods applied to parallel texts (Och and Ney, 2000; Liang et al., 2006). The projected annotations can then be used to automatically generate semantic processors for the target language. In this way we would be able to provide NLP processors with- out training data for the target language. The experiments are focused on 4 languages: German, English, Spanish and Italian, and our empirical evaluation results show that our method obtains competitive results when compared with models trained on gold-standard out-of-domain data. This shows that our projection algorithm is effective to transport NER annotations across languages via parallel data thus providing a fully automatic method to obtain NER taggers for as many as the number of languages aligned via parallel corpora

Power Flow Solution for Radial Distribution Networks

Power flow analysis on distribution systems is not having enough attention as compared to transmission systems. Generally, distribution networks are radial and the resistance to reactance ratio, R/X is high. By making use of the special structure of radial network, a simple method is first developed to obtain the connection matrix and hence the nodes beyond any specified branch, which is the branch-node matrix by using the special structure of radial distribution network. The necessary formulas are derived to calculate the receiving-end voltage in terms of the sending-end voltage and the receiving-end line flows. At each and every of the iterations, receiving-end voltages are updated by computing the line losses. The main aim of this project is to attain a simple power flow method which is suitable for solving radial distribution networks and develop the necessary MATLAB programme. The specially designed MATLAB programme to solve radial distribution networks was successfully developed and tested on several standard radial distribution networks. Meanwhile, Newton-Raphson power flow method is developed to test the radial networks for strengthening the validity of the results obtained. Besides, comparisons are made between both Newton-Raphson power flow method and proposed approach. The proposed approach for radial distribution network can be implemented on any practical data

Analysis of Power-aware Buffering Schemes in Wireless Sensor Networks

We study the power-aware buffering problem in battery-powered sensor networks, focusing on the fixed-size and fixed-interval buffering schemes. The main motivation is to address the yet poorly understood size variation-induced effect on power-aware buffering schemes. Our theoretical analysis elucidates the fundamental differences between the fixed-size and fixed-interval buffering schemes in the presence of data size variation. It shows that data size variation has detrimental effects on the power expenditure of the fixed-size buffering in general, and reveals that the size variation induced effects can be either mitigated by a positive skewness or promoted by a negative skewness in size distribution. By contrast, the fixed-interval buffering scheme has an obvious advantage of being eminently immune to the data-size variation. Hence the fixed-interval buffering scheme is a risk-averse strategy for its robustness in a variety of operational environments. In addition, based on the fixed-interval buffering scheme, we establish the power consumption relationship between child nodes and parent node in a static data collection tree, and give an in-depth analysis of the impact of child bandwidth distribution on parent's power consumption. This study is of practical significance: it sheds new light on the relationship among power consumption of buffering schemes, power parameters of radio module and memory bank, data arrival rate and data size variation, thereby providing well-informed guidance in determining an optimal buffer size (interval) to maximize the operational lifespan of sensor networks

Managing the cross-industry networks of the audiovisual sector: a perspective from the independent screen productions in the UK and Taiwan

The thesis is a qualitative account of the much neglected issues of the bottom-up, and interconnected organization of the Cross-Industry Network (CIN) phenomena within the Audiovisual Sector (AVS). The aims are achieved by exploring the why and how of the independent screen content producers in developing CIN during the production process. By conceptualizing the CIN phenomenon as a Complex Adaptive System (CAS), I used its theories as analogies to analyze the multi-case and multi-level studies conducted at two scenarios of independent TV production sector in the UK/ the developed, and the independent film production sector in Taiwan/the developing. My research produced the following four conclusions. 1. From Top-Down Industry Disintegration to Bottom-up Production Reconfiguration The industrial disintegration of the media industry has resulted in the reconfiguration of content production networks and intense self-adaptation of creative producers who are facing multi-directional connections within the CIN during their production process. Such adaptation reveals tensions between the producers’ self-perception as ‘independent’ and ‘creative’ producers and their networking decisions and actions. 2. From Managing the Creative Project to Managing the Creative and Commercial Venture The evolution of the CIN in the creative and media production is not entirely top-down/linear/serial, but more accurately, bottom-up/ non-linear/parallel. These internal self-organizing dynamics enable the production network to radiate outwardly, which induces trade-offs between and beyond commercial and creative priorities. 3. From Distribution-led Value System to Production-led Microcosm The production process has evolved its own diverse CIN, involving different types of relationships, a higher degree of complexity and structural tensions inherent in the value-creating system. Such production-led networking functions are the most fundamental source for developing broader CIN and the economic return for creative producers. 4. From Network Adaptation to Complex Adaptive System The networking activities of independent and creative producers radiate and interact outwards to connect and affect all levels of the network, resulting in unexpected directions and complex collaborations. In particular, the elements of multi-directional adaptation and tensions of the involved network actors have an important impact on the emergence and organization of the network. The main contributions of the research are firstly to have taken a bottom-up analysis by integrating the micro-level organizational complexity of the independent production into the theorizing about the AVS; and secondly, to have placed the intangible values and real practice of creative producers at the centre of the network study

Effect of tones on voice onset time (VOT) in Cantonese aspirated stops

"A dissertation submitted in partial fulfillment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2010."Includes bibliographical references (p. 22-24).Thesis (B.Sc)--University of Hong Kong, 2010.The study investigated the possible interaction between VOT values associated with aspirated stops produced at six different lexical tones (high falling, high rising, mid level, mid-low falling, mid-low rising and mid-low level) in Cantonese. A total of 27 male Cantonese speakers were recruited and they were instructed to read phrases containing targeted CV syllables formed by the aspirated Cantonese stops (/ph/, /th/, and /kh/) and the vowel /a/ at the six tones. VOT analysis revealed that, across aspirated stops, tones in the upper tone register produced shorter VOT while those in the lower tone register had longer VOT values. In particular, mid-low rising tone showed the longest VOT than all other tones. This finding indicated an interaction between VOT and tone during Cantonese stop production is confirmed.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Re-evaluation of the surface ruptures of the November 1951 earthquake series in eastern Taiwan, and its neotectonic implications

The earthquakes of November 1951 constitute the most destructive seismic episode in the recorded history of the Longitudinal Valley, eastern Taiwan. However, information about their source parameters is sparse. To understand the relationship between the 1951 ruptures and new interpretations of the regional neotectonic architecture of the Longitudinal Valley, we re-evaluated the November 1951 ruptures by analyzing old documents, reports and photographs, and by interviewing local residents who experienced the earthquake. As a result, we have revised significantly the rupture map previously published. We divide the surface ruptures from south to north into the Chihshang, Yuli, and Rueisuei sections. The first shock of the 1951 series probably resulted from the Chihshang rupture, and the second shock probably resulted from the Yuli and Rueisuei ruptures. The lengths of these ruptures indicate that the two shocks had similar magnitudes. The Chihshang and Rueisuei ruptures are along segments of the Longitudinal Valley fault, a left-lateral oblique fault along which the Coastal Range thrusts westward over the Longitudinal Valley. The Yuli rupture, on the other hand, appears to be part of a separate, left-lateral strike-slip Yuli fault, which traverses the middle of the Longitudinal Valley. The complex behavior of these structures and interaction between them are important in understanding the future seismic hazard of the area

Measuring Confidence of Assurance Cases in Safety-Critical Domains

Evaluation of assurance cases typically requires certifiers’ domain knowledge and experience, and, as such, most software certification has been conducted manually. Given the advancement in uncertainty theories and software traceability, we envision that these technologies can synergistically be combined and leveraged to offer some degree of automation to improve the certifiers’ capability to perform software certification. To this end, we present DS4AC, a novel confidence calculation framework that 1) applies the Dempster-Shafer theory to calculate the confidence between a parent claim and its children claims; and 2) uses the vector space model to evaluate the confidence for the evidence items using traceability information. We illustrate our approach on two different applications, where safety is the key property of interest for both systems. In both cases, we use the Goal Structuring Notation to represent the respective assurance cases and provide proof of concept results that demonstrate the DS4AC framework can automate portions of the evaluation of assurance cases, thereby reducing the burden of manual certification process