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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Heterocycles for life-sciences applications and information storage

Shrestha, Tej Bahadur January 1900 (has links)
Doctor of Philosophy / Department of Chemistry / Stefan H. Bossmann / The photochromic spirodihydroindolizine/betaine (DHI/B) system has been reinvestigated applying picosecond, microsecond, stationary absorption measurements, and NMR-kinetics. The first surprise was that the electronic structure of the betaines is quite different than commonly assumed. The photochemical ring-opening of DHIs to betaines is a conrotatory 1,5 electrocyclic reaction, as picosecond absorption spectroscopy confirms. The (disrotatory) thermal ring-closing occurs from the cisoid betaine. The lifetime of the transoid betaine is 60 s at 300 K, whereas the lifetime of the cisoid isomer is of the order of 250 microseconds. According to these results, the electrocyclic back reaction of the betaines to the DHI is NOT rate determining, as previously thought, but the cisoid-transoid-isomerization of the betaine. Although the presence of a second nitrogen atom increases the photostability of the spirodihydroindolizine-pyridazine/betaine-system remarkably, the photochemical reaction mechanism appears to be exactly the same for spirodihydroindolizine-pyridazine/betaine-system. A nondestructive photoswitch or an information recording systems has been explored using styryl-quinolyldihydroindolizines. Both isomers DHI and betaine are fluorescent. When the blue betaine is stabilized in a thin polymethyl methacrylate (PMMA) matrix, it is stable for several hours even in room temperature and very stable at 77K. Although irradiation of visible light = 532 nm allows the photo-induced reaction of the Betaine back to the DHI, a nondestructive read-out can be performed at λ = 645 nm upon excitation with λ = 580 nm. Image recording (write) and read-out, as well as information storage (at 77K) have been demonstrated. Charged and maleimide-functionalized DHI/B systems have beed synthesized for use as photochemical gates of the mycobacterial channel porin MspA. Positively charged and maleimide functionalized DHI groups that were attached to the DHI/B-system permit the binding of the photoswitch to selective positions in the channel proteins due to the presence of a cysteine moiety. An inexpensive new method for the large scale synthesis of coelenterazine is developed. A modified Negishi coupling reaction is used to make pyrazine intermediates from aminopyrazine as an economical starting material. This method permits the use of up to 1g coelenterazine per kg body weight and day, which turns the renilla transfected stem cells into powerful light sources.
52

Data Exploration Interface for Digital Forensics

Dontula, Varun 17 December 2011 (has links)
The fast capacity growth of cheap storage devices presents an ever-growing problem of scale for digital forensic investigations. One aspect of scale problem in the forensic process is the need for new approaches to visually presenting and analyzing large amounts of data. Current generation of tools universally employ three basic GUI components—trees, tables, and viewers—to present all relevant information. This approach is not scalable as increasing the size of the input data leads to a proportional increase in the amount of data presented to the analyst. We present an alternative approach, which leverages data visualization techniques to provide a more intuitive interface to explore the forensic target. We use tree visualization techniques to give the analyst both a high-level view of the file system and an efficient means to drill down into the details. Further, we provide means to search for keywords and filter the data by time period.
53

A study of three paradigms for storing geospatial data: distributed-cloud model, relational database, and indexed flat file

Toups, Matthew A 13 May 2016 (has links)
Geographic Information Systems (GIS) and related applications of geospatial data were once a small software niche; today nearly all Internet and mobile users utilize some sort of mapping or location-aware software. This widespread use reaches beyond mere consumption of geodata; projects like OpenStreetMap (OSM) represent a new source of geodata production, sometimes dubbed “Volunteered Geographic Information.” The volume of geodata produced and the user demand for geodata will surely continue to grow, so the storage and query techniques for geospatial data must evolve accordingly. This thesis compares three paradigms for systems that manage vector data. Over the past few decades these methodologies have fallen in and out of favor. Today, some are considered new and experimental (distributed), others nearly forgotten (flat file), and others are the workhorse of present-day GIS (relational database). Each is well-suited to some use cases, and poorly-suited to others. This thesis investigates exemplars of each paradigm.
54

Thin Film Carbon Nanofuses for Permanent Data Storage

Laughlin, Kevin Robert 01 April 2018 (has links)
We have fabricated nanofuses from thin-film, arc-evaporation carbon for use in permanent data storage. Thin film carbon fuses have fewer fabrication barriers and retain the required resistivity and structural stability to work as a data storage medium. Carbon thin films were characterized for their electrical, microstructural, and chemical bonding properties. Annealing the thin-film carbon in an argon environment at 400°C reduced the resistivity from about 4*10-2 Ω cm as deposited down to about 5*10-4 Ω cm, allowing a lower blowing voltage. Nanofuses with widths ranging from 200 nm down to 60 nm were fabricated and tested. They blow with voltages between 2 V and 5.5 V, and the nanofuses remain stable in both a "1" and a "0" state under a constantly applied read voltage of 1 volt for over 90 hours, corresponding to a cumulative time of >1012 reads.
55

Liquid Crystal on Silicon Displays Characterization for Diffractive Applications and for Holographic Data Storage in Photopolymers / Caracterización de pantallas LCoS para aplicaciones en óptica difractiva y almacenamiento holográfico de información en fotopolímeros

Martínez Guardiola, Francisco Javier 23 July 2015 (has links)
In this PhD Thesis I present some methods for characterizing PA-LCoS microdisplays. It is useful to fully characterize this type of devices for evaluating its performance required in different applications. We have tested its validity in different applications such as diffractive optics elements (DOEs). Finally we apply these microdisplays in a full holographic data storage scheme using a photopolymer as holographic recording medium. We evaluate the capability of PVA/AA photopolymer for this holographic data storage system that incorporates as a novelty a convergent correlator geometry.
56

METADATA-BASED IMAGE COLLECTING AND DATABASING FOR SHARING AND ANALYSIS

Wu, Xi 01 January 2019 (has links)
Data collecting and preparing is generally considered a crucial process in data science projects. Especially for image data, adding semantic attributes when preparing image data provides much more insights for data scientists. In this project, we aim to implement a general-purpose central image data repository that allows image researchers to collect data with semantic properties as well as data query. One of our researchers has come up with the specific challenge of collecting images with weight data of infants in least developed countries with limited internet access. The rationale is to predict infant weights based on image data by applying Machine Learning techniques. To address the data collecting issue, I implemented a mobile application which features online and offline image and annotation upload and a web application which features image query functionality. This work is derived and partly decoupled from the previous project – ImageSfERe (Image Sharing for Epilepsy Research), which is a web-based platform to collect and share epilepsy patient imaging.
57

THE I: A CLIENT-BASED POINT-AND-CLICK PUZZLE GAME

Lewis, Aldo 01 June 2014 (has links)
Given mobile devices’ weak computational power, game programmers must learn to create games with simple graphics that are engaging and easy to play. Though seldom created for phones and tablets, puzzle games are a perfect fit. In recent years, the genre has gained a following and even won some acclaim. Games like Myst, The Seventh Guest and Portal all engage gamers with challenging puzzles and then reward them with story components upon task fulfillment. Few such games have been created for mobile devices, in part due to the difficulty of developing for devices with different operating systems. Android, WebIOS and Windows Phone all have different software development kits that produce a final product incompatible with operating systems other than what it was developed for. One promising solution is to use browser technology to deliver games since all devices are geared to interact with the Web through browsers such as Internet Explorer, Mozilla Firefox, and Google Chrome. The aim of this project was to build a puzzle game that can be run on any digital device. The project can be accessed without any plug-ins and was created by using web technologies such as JQuery, Touch Punch, local storage, and WebGL. JQuery allows drag and drop functionality and Touch Punch allows the JQuery functionality intended for a mouse to work on a touch interface. Local storage provides storage on a user’s device, as opposed to a server, and WebGL enables graphics processing on a user’s tablet or phone through web commands.
58

ANDROID MOBILE APPLICATION FOR HOSPITAL EXECUTIVES

Nalagatla, Vihitha 01 March 2017 (has links)
Hospitals are the largest and most complex organizations where health care is provided. Safe and effective patient care services in hospitals depend on the efficient decisions made by hospital executives. The main task of hospital executives is to ensure the hospital can provide high quality patient care and services. “Android Mobile Application For Hospital Executives” is an Android application used for displaying hospital performance metrics on a daily basis. This application allows hospital executives to review and monitor hospital operational data with ease of access and in a portable manner. Thus, reducing the effort of the hospital executives to perform their tasks.
59

STUDENT CLASS WAITING LIST ENROLLMENT

LACHAGARI, AISHWARYA 01 March 2017 (has links)
At California State University San Bernardino, students can ordinarily register online and join waiting lists when a course is full. However, the system does not support waiting lists when a course has associated laboratory sections. This project addresses this problem.
60

ORGANIZE EVENTS MOBILE APPLICATION

Gudimetla, Thakshak Mani Chandra Reddy 01 December 2018 (has links)
In a big organization there are many events organized every day. To know about the events, we typically need to check an events page, rely on flyers or on distributed pamphlets or through word of mouth. To register for an event a user now a days typically does this online which involves inputting user details. At the event, the user either signs a sheet of paper or enters credentials in a web page loaded on a tablet or other electronic device. Typically, this is a time-consuming process with many redundancies like entering user details every time the user wants to register for a new event and re-entering the details at the event. This project designs a system that eliminates these redundancies and improves event management.

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