Delay-Exponent of Bilayer Anytime Code

In this paper, we study the design and the delay-exponent of anytime codes over a three terminal relay network. We propose a bilayer anytime code based on anytime spatially coupled low-density parity-check (LDPC) codes and investigate the anytime characteristics through density evolution analysis. By using mathematical induction technique, we find analytical expressions of the delay-exponent for the proposed code. Through comparison, we show that the analytical delay-exponent has a close match with the delay-exponent obtained from numerical results.Comment: Accepted for presentation in ITW-2014. 5 Pages, 3 Figure

Single-molecule DNA detection in nanopipettes using high-speed measurements and surface modifications

Inspired by transmembrane pores found in cell membranes and the operating principle of the Coulter counter used for cell counting, nanopore biosensors have emerged as a tool for single-molecule detection. This thesis describes single-molecule DNA detection through resistive pulse sensing using nanopipettes, a novel subclass of solid-state nanopores. In the first part of this thesis, double-stranded (ds) DNA-nanopipette surface interactions were probed in 1 M KCl electrolyte using DNA molecules with lengths ranging from 48.5 to 4 kilobase pair (kbp). A custom-built current amplifier was employed for low-noise and high-bandwidth measurements. Results from these experiments were used to theoretically rationalise DNA-surface interactions and suggest that dsDNA adsorption to the nanopipette surface prior to translocation through the pore is likely to be an important factor in the process. Subsequently, initial investigations to probe DNA-surface interactions were carried out by modifying the surface charge of nanopipettes using silanes. Additionally, experiments were performed to detect shorter dsDNA lengths. In 1 M KCl electrolyte, 200 base pair (bp) long dsDNA was successfully detected using the low-noise and high-bandwidth current amplifier. However detection of 100 bp long dsDNA required the use of 2 or 4 M LiCl electrolyte. Attention was finally shifted to the detection of 100 bp dsDNA in 1 M KCl electrolyte using functionalised lipid bilayer coated nanopipettes. Additional techniques were employed to prepare and characterise the lipid bilayers, including atomic force microscopy (AFM) and dynamic light scattering (DLS). The promising preliminary results provide a framework for further experiments using functionalised lipid bilayers to coat nanopipettes. Overall, results of the aforementioned research presented in this thesis demonstrate high-speed single-molecule detection of DNA and provide novel insights into the translocation dynamics of DNA molecules in nanopipettes and the sensing capabilities of nanopipettes.Open Acces

Laser Pulses

This book discusses aspects of laser pulses generation, characterization, and practical applications. Some new achievements in theory, experiments, and design are demonstrated. The introductive chapter shortly overviews the physical principles of pulsed lasers operation with pulse durations from seconds to yoctoseconds. A theory of mode-locking, based on the optical noise concept, is discussed. With this approximation, all paradoxes of ultrashort laser pulse formation have been explained. The book includes examples of very delicate laser operation in biomedical areas and extremely high power systems used for material processing and water purification. We hope this book will be useful for engineers and managers, for professors and students, and for those who are interested in laser science and technologies

Positron interactions at low-dimensional condensed surfaces

A microprocessor control system for automatic data acquisition in a photon spectroscopy system was developed. The control process performed Doppler broadening measurements over the temperature range 4.2-600K with simultaneous recording when necessary of pressure. After work on the chalcogenide semiconductor (Pb,Ge)Te, Doppler broadening studies concentrated on the phenomenon of gas condensation on cooled graphite substrates. This class of adsorbent, of proven homogeneity was found ideal to explore the interaction of positrons at surfaces. By measurement of positronium, adlayer formation of methane, krypton, argon, nitrogen and oxygen was followed. All gases produced peaks in positronium emission with an investigation of the substrate further revealing an underlying thermal variation. Sound evidence in the form of accurate simultaneous pressure measurements and isotherms was found for a coverage of one half at the maximum in positronium. These studies of gas physisorption were conducted under a variety of temperatures and with pressures embracing atmospheric to under one Torr. Although results for the gases were of the same form each produced different maximum levels of positronium which appeared to relate to substrate-adsorbate binding energy. Maximum emission in the case of argon showed a temperature dependence however this requires verification. Oxygen was a special case as it yielded 12[percent] para-positronium at half-coverage. The coupling of this to a low 1.5[percent] ortho-positronium emission was attributed to chemical quenching. A convolution procedure based on the superposition of an additional para-positronium derived narrow gaussian to the usual gaussian and inverted parabola components was employed for an estimate of the positronium energy. This was used to attack the question of whether positronium is bound at the surface or is created flying.<p

Virtualizing Reconfigurable Architectures: From Fpgas To Beyond

With field-programmable gate arrays (FPGAs) being widely deployed in data centers to enhance the computing performance, an efficient virtualization support is required to fully unleash the potential of cloud FPGAs. However, the system support for FPGAs in the context of the cloud environment is still in its infancy, which leads to a low resource utilization due to the tight coupling between compilation and resource allocation. Moreover, the system support proposed in existing works is limited to a homogeneous FPGA cluster comprising identical FPGA devices, which is hard to be extended to a heterogeneous FPGA cluster that comprises multiple types of FPGAs. As the FPGA cloud is expected to become increasingly heterogeneous due to the hardware rolling upgrade strategy, it is necessary to provide efficient virtualization support for the heterogeneous FPGA cluster. In this dissertation, we first identify three pairs of conflicting requirements from runtime management and offline compilation, which are related to the tradeoff between flexibility and efficiency. These conflicting requirements are the fundamental reason why the single-level abstraction proposed in prior works for the homogeneous FPGA cluster cannot be trivially extended to the heterogeneous cluster. To decouple these conflicting requirements, we provide a two-level system abstraction. Specifically, the high-level abstraction is FPGA-agnostic and provides a simple and homogeneous view of the FPGA resources to simplify the runtime management and maximize the flexibility. On the contrary, the low-level abstraction is FPGA-specific and exposes sufficient low-level hardware details to the compilation framework to ensure the mapping quality and maximize the efficiency. This generic two-level system abstraction can also be specialized to the homogeneous FPGA cluster and/or be extended to leverage application-specific information to further improve the efficiency. We also develop a compilation framework and a modular runtime system with a heuristic-based runtime management policy to support this two-level system abstraction. By enabling a dynamic FPGA sharing at the sub-FPGA granularity, the proposed virtualization solution can deploy 1.62x more applications using the same amount of FPGA resources and reduce the compilation time by 22.6% (perform as many compilation tasks in parallel as possible) with an acceptable virtualization overhead, i.e., Finally, we use Liquid Silicon as a case study to show that the proposed virtualization solution can be extended to other spatial reconfigurable architectures. Liquid Silicon is a homogeneous reconfigurable architecture enabled by the non-volatile memory technology (i.e., RRAM). It extends the configuration capability of existing FPGAs from computation to the whole spectrum ranging from computation to data storage. It allows users to better customize hardware by flexibly partitioning hardware resources between computation and memory based on the actual usage. Instead of naively applying the proposed virtualization solution onto Liquid Silicon, we co-optimize the system abstraction and Liquid Silicon architecture to improve the performance

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

A Corpus-driven Approach toward Teaching Vocabulary and Reading to English Language Learners in U.S.-based K-12 Context through a Mobile App

In order to decrease teachers’ decisions of which vocabulary the focus of the instruction should be upon, a recent line of research argues that pedagogically-prepared word lists may offer the most efficient order of learning vocabulary with an optimized context for instruction in each of four K-12 content areas (math, science, social studies, and language arts) through providing English Language Learners (ELLs) with the most frequent words in each area. Educators and school experts have acknowledged the need for developing new materials, including computerized enhanced texts and effective strategies aimed at improving ELLs’ mastery of academic and STEM-related lexicon. Not all words in a language are equal in their role in comprehending the language and expressing ideas or thoughts. For this study, I used a corpus-driven approach which is operationalized by applying a text analysis method. For the purpose of this research study, I made two corpora, Teacher’s U.S. Corpus (TUSC) and Science and Math Academic Corpus for Kids (SMACK) with a focus on word lemma rather than inflectional and derivational variants of word families. To create the corpora, I collected and analyzed a total of 122 textbooks used commonly in the states of Florida and California. Recruiting, scanning and converting of textbooks had been carried out over a period of more than two years from October 2014 to March 2017. In total, this school corpus contains 10,519,639 running words and 16,344 lemmas saved in 16,315 word document pages. From the corpora, I developed six word lists, namely three frequency-based word lists (high-, mid-, and low-frequency), academic and STEM-related word lists, and essential word list (EWL). I then applied the word lists as the database and developed a mobile app, Vocabulary in Reading Study – VIRS, (available on App Store, Android and Google Play) alongside a website (www.myvirs.com). Also, I developed a new K-12 dictionary which targets the vocabulary needs of ELLs in K-12 context. This is a frequency-based dictionary which categorizes words into three groups of high, medium and low frequency words as well as two separate sections for academic and STEM words. The dictionary has 16,500 lemmas with derivational and inflectional forms

Modelling framework of solar assisted dehumidification system to generate freshwater from "Thin air"

Freshwater scarcity is a major obstacle of growth and prosperity for many nations in the world. Conventional centralised freshwater supply options in general are depleting and the unanticipated social and environmental costs of alternative solutions are emerging. Similar to energy, water sector may also need to explore renewable decentralised freshwater alternatives such as atmospheric moisture as discussed in this thesis. For hot and humid regions, condensed water is unwillingly discharged out of air-conditioning systems and the energy consumed for condensation to full humidity comfort level is wasted. Only a few limited small-scale experimental studies and no systematic modelling have been found in the literature on atmospheric water capture. This thesis works to fill some of this gap by developing an understanding of the fundamental factors that have and continue to challenge the development of technologies for atmospheric water capture. In this thesis, a framework is developed encompassing several modelling elements for assessment of feasibilities of moist air dehumidification technologies for atmospheric water capture. This framework integrates technical, meteorological and economic modelling elements. In the technosphere, detailed models of thermoelectric and absorption cooling are developed as potential dehumidification technologies. These models are interfaced to renewable energy input algorithms, namely solar photo-voltaic (PV) and solar-thermal. Solar energy collection technologies are also part of this framework which includes models of solar PV systems and evacuated tube collectors (ETCs). Studies of such integration of solar-assisted dehumidification and associated analysis for atmospheric water capture are limited in the literature. Fundamental solar energy input models are developed and interfaced to meteorological data to provide geographical location specific analysis. In this way the model framework is generic and applicable to any location on Earth where meteorological data is available. Finally, an economic modelling component completes the framework to provide comprehensive techno-economic assessments of different technologies for atmospheric water capture. This framework therefore provides a tool to support decision making related to feasibilities of different technologies associated with water capture from atmosphere. Along the way to developing the modelling framework, a detailed categorisation of dehumidification systems is established and a model to estimate condensation rates based on local climate data is built. The hurdle of condensation energy requirement is highlighted through simulation results. To alleviate this energy burden, an assessment of renewable solar energy input is then made. Techno-economic challenges for two different climates, Sydney and Abu Dhabi are examined and compared throughout this thesis providing comparisons for water and energy profiles. Several modelling components are developed and presented f or this purpose, requiring implementations in different modelling environments including Matlab, Trnsys, Homer and VBA. Based on the operation principles, dehumidification techniques are categorised into three categories in this thesis (Fig. 2.2). Gas separation membrane technologies were modelled but are not included in this thesis presentation because initial analysis showed they suffer from several key technical drawbacks primarily associated with the sensitivity to fluctuations in feed air temperature and humidity. Technologies in the cooling surfaces category in general use electrical or mechanical power to circulate and compress a refrigerant and cooling down conductive surfaces or coils. This process aims to decrease the temperature of moist air stream below dew point where water vapour molecules start to bond and settle forming the condensation stream. Amongst a wide range of cooling surface techniques, thermoelectric cooler (TEC) devices are attachable to cooling surfaces without using a refrigerant medium. A conceptual TEC dehumidification system is modelled in this thesis targeted at moist air streams with ambient temperature ranges (10-50) C and relative humidity ranges (10-100) %. For large-scale water production, the energy cost is calculated and found to be the major factor contributing to more than 95% of the total cost of generated water. This model is implemented for Sydney and Abu Dhabi case studies by using their annual typical meteorological weather data. This shows the generic nature of the applicability of the model and in this specific comparison confirms the influence of energy consumption over the cost of generated water in those two very different regions. However, lower local utility rates and favourable climatic conditions for dehumidification in Abu Dhabi show significant differentiation in water cost over Sydney. To confront excessive energy demands for atmospheric water capture, the idea of facilitating solar energy via PV panels is examined in this thesis. A comprehensive solar algorithm is developed and implemented to optimise solar collector positioning and for calculating solar penetration ratios for Sydney and Abu Dhabi. As far as the author is aware, this is the first time such optimal position calculation for Sydney and Abu Dhabi is done. It is found that optimal surface tilt angles for Sydney and Abu Dhabi are 32 and 22 respectively, while optimal surface azimuth angles for Sydney and Abu Dhabi are 195 and 16 respectively. This algorithm is generic in its structure allowing such calculation to be executed for any city in the world and is later used in this thesis for calculations associated with a new ETC diffuse at reflector (DFR) model. This thesis also presents a detailed economic model for prediction of utility costs with consideration for CAPEX, OPEX, subsidies and carbon taxation. It is found that investing a $338,000 on a PV array of 100 kW at current utility rates can meet 53$15 /kL. If this system is projected to work during the day only, solar penetration ratio will substantially increase and could meet the entire diurnal load for dehumidification in Abu Dhabi. If the capital cost of developing such system is affordable, absorption model can be further optimised to specifically match local conditions in respect to solar radiation and energy sources where the cost of generated water can economically compete with other conventional sources. In regions such as Abu Dhabi, the idea of having small-scale dehumidification system where the energy demand is mostly met by solar radiation and the volume of generated water is freely controlled and managed by household seems appealing