Thesis (Ph.D.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 93-99)

Σκοπός αυτής της διπλωματικής εργασίας ήταν η ανάπτυξη μιας ασφαλούς εφαρμογής για έξυπνο τηλεφωνο (smartphone) με λειτουργικό σύστημα Microsoft Windows Mobile 6 χρησιμοποιώντας το .NET Compact Framework 3.5 (.NET CF) αλλά και η αποτίμηση της απόδοσής της. Αρχικά αξιολογήσαμε την απόδοση των αλγόριθμων AES, DES, MD5, SHA1 που παρέχει το .NET CF. Επειδή το .NET CF 3.5 δεν παρέχει κάποια συνάρτηση ασφαλούς κατακερματισμού, υλοποιήσαμε δύο παραλλαγές αλγόριθμου HMAC. Η πρώτη βασίζεται στον αλγόριθμο MD5 και η δεύτερη στο SHA1. Η αποτίμηση της απόδοσης έγινε για μεγέθη εισόδων 1 ΚΒ, 4 ΚΒ, 32 ΚΒ, 512 ΚΒ και 1 ΜΒ. Από τα αποτελέσματα που προέκυψαν διαπιστώσαμε ότι ο AES είναι πολύ πιο αργός από τον DES. Επίσης ο SHA1 είναι πιο αργός από τον MD5, κάτι το οποίο ισχύει για τον HMAC-SHA1 συγκριτικά με τον HMAC-MD5. Αναπτύξαμε στη συνέχεια μία εφαρμογή για την ασφαλή αποθήκευση αρχείων σε smartphone. H εφαρμογή υλοποιεί για τη διαχείριση κλειδιών κρυπτογράφησης τόσο το κλασσικό πρωτόκολλο, όσο και τις δύο παραλλαγές του πρωτοκόλλου ελεγχόμενης τυχαιότητας, το οποίο έχει προταθεί στη βιβλιογραφία. Ολοκληρώνοντας την εργασία μας, αποτιμήσαμε την απόδοση των τρίων πρωτοκόλλων για διάφορα μεγέθη αρχείων. Τα αποτελέσματα των μετρήσεων μας επιβεβαιώνουν ότι το πρωτόκολλο ελεγχόμενης τυχαιότητας επιτυγχάνει προηγμένα χαρακτηριστικά ασφάλειας με μικρό υπολογιστικό κόστος στην πλατφόρμα Microsoft Windows Mobile 6. / -

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Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Road accidents are a growing concern for governments and is rising to become one of the leading causes of death in developing countries. Aggressive driving is one of the major causes of road accidents, and it is therefore important to investigate ways to improve people's driving habits. The ubiquitous presence of smartphones provides a new platform on which to implement sensor networks in vehicles, and therefore this thesis focuses on the use of smartphones to monitor a person's driving behaviour. The framework for a smartphone-based system that can detect and classify various driving manoeuvres is researched. As a proof of concept, a system is developed that specifically detects lateral driving manoeuvres and that classifies them as aggressive or not, using a supervised learning classification algorithm. Existing solutions found in research literature are investigated and presented. The best existing solution, a dynamic time warping classification approach, is also implemented and tested. We use an aggressive driving model that is based on the angle of a turn, the lateral force exerted on the vehicle and its speed through the turn. The tests and results of the implemented manoeuvre detection and classifcation algorithms are presented, and thoroughly discussed. The performance of each classifer is tested using the same data set, and a quantitative comparison are made between them. Ultimately, a lateral driving manoeuvre detection and recognition system was successfully developed, and its potential to be implemented on a smartphone was substantiated. The suitability of supervised learning classi ers for classifying aggressive driving, in comparison to dynamic time warping classifcation, was successfully demonstrated and used to validate our aggressive driving model. Conceivably, this work can be employed in the future to develop an holistic smartphone-based driver behaviour monitoring system, which can be easily deployed on a large scale to help make the public drive better. This would make our roads safer, reducing the occurrence of road accidents and fatalities. / AFRIKAANSE OPSOMMING: Padongelukkige is 'n groeiende bekommernis vir regerings en is een van die hoof oorsake van sterftes in ontwikkelende lande. Aggressiewe bestuur is een van die grootste oorsake van padongelukke, en dit is dus belangrik om ondersoek in te stel oor hoe mense se bestuurgewoontes verbeter kan word. Die alomteenwoordigheid van slimfone bied 'n nuwe platform waarop sensor netwerke geïmplementeer kan word in voertuie. Daarom fokus hierdie tesis op die gebruik van slimfone om 'n persoon se bestuurgedrag te moniteer. Die raamwerk vir 'n slimfoon-gebaseerde stelsel wat verskeie bestuurbewegings kan opspoor en klassifiseer is nagevors. As 'n bewys van die konsep, is 'n stelsel ontwikkel wat spesifiek laterale bestuurbewegings opspoor en dan klassifiseer of dit aggressief is of nie, met behulp van 'n klassifikasie algoritme wat onder toesig geleer is. Bestaande oplossings gevind in navorsingsliteratuur word ondersoek en aangebied. Die beste bestaande oplossing, 'n dinamiese tyd buiging klassifikasie benadering, word ook geïmplementeer en getoets. Ons gebruik 'n aggressiewe bestuurmodel wat gebaseer is op die hoek van 'n draai, die laterale krag wat uitgeofen is op die voertuig en sy spoed deur die draai. Die toetse en die resultate van die geïmplementeer beweging opsporing en klassifisering algoritmes word aangebied, en deeglik bespreek. Die prestasie van elke klassifiseerder is getoets met behulp van dieselfde stel data, en 'n kwantitatiewe vergelyking is tussen beide gemaak. Oplaas is 'n laterale bestuurbeweging bemerking en herkenning stelsel suksesvol ontwikkel en sy potensiaal om geïmplementeer te word op 'n slimfoon is gestaaf. Die geskiktheid van die onder-toesig-geleerde klassifiseerders vir die klassifikasie van aggressiewe bestuur, in vergelyking met dinamiese tyd buiging klassifikasie, was suksesvol gedemonstreer en gebruik om ons aggressiewe bestuurmodel te bewys. Hierdie werk kan in die toekoms gebruik word in 'n holistiese slimfoon-gebaseerde bestuurdergedrag monitering stelsel, wat maklik op groot skaal ontplooi kan word om te help verseker dat die publiek beter bestuur. Dit sal ons paaie veiliger maak, en die voorkoms van padongelukke en sterftes verminder.

Thesis (MScAgric)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Daily daylight fertigation regimes (involvinq drip fertigation, on a daily basis, during the daylight hours) are becoming widely used in the South African citrus industry in the endeavor to enhance tree productivity. Such regimes could provide sensitive nutrient and moisture management, reducing plant stress in general as well as the response time to root-directed cultural activities. There is a need to evaluate the efficacy of daily daylight fertigation systems relative to conventional irrigation systems. Standard horticultural evaluation of orchard management practices is very time consuming. We opted for physiological studies comparing plant stress levels, in an attempt to quantify plant performance under each system. Citrus trees under daily daylight fertigation and conventional micro-jet and drip-irrigated regimes were monitored to establish plant stress levels as indicated by sap flow, xylem water potential, stomatal conductance and chlorophyll a fluorescence. Plants under a daily daylight fertigation regime are believed to have good soil water conditions in their rooting volume, and therefore experience negligible baseline levels of stress. The trees do, however, experience midday depression in stomatal conductance, to a lesser degree, but not unlike trees under conventional regimes. It appears as if a larger rooting volume of microjet irrigation regimes enhances recovery from the midday depression. It is recommended that producers optimise productivity during the moming hours, by early irrigation, so that plants can function optimally, whilst environmental conditions are most favourable for high physiological activity. We also assessed the effect of withholding water from trees adapted to a daily daylight fertigation regime to evaluate the risk involved with short-term water deficits in trees adapted to this regime, as well as the usefulness of physiological techniques for identifying water stress. Stomatal conductance and xylem water potential indicated water stress sooner than the other physiological parameters. Citrus trees seem to be relatively insensitive to water deficit stress as measured by sap flow and chlorophyll a fluorescence. Sap flow is buffered by tree capacitance, and although mediated via stomatal conductance, atmospheric conditions and not the soil water content primarily determine it. As daily fertigation is applied to trees under DOF regimes, they exhibit more optimal levels of xylem water potential and stomatal conductance, compared to trees from which water is withheld. Although alleviating it to a degree, daily irrigation did not mitigate the midday depression in these values. Seen over a season, even small enhancements of stomatal conductance (and with it photosynthesis and possibly, growth) and xylem water potential, could incrementally produce higher yields. / AFRIKAANSE OPSOMMING: In die strewe na verhoogde boomproduktiwiteit, word daaglikse sproeibemesting (deur 'n drupbesproeiingsstelsel toegedien tydens die dagligure) al meer algemeen in die Suid Afrikaanse sitrusbedryf gebruik. Hierdie praktyk verminder algemene plantstres deur baie spesifieke voedingsen vogbeheer, en verkort ook die plant se reaksietyd op wortelgerigte bewerkingsaktiwiteite. Dit is nodig om die relatiewe voordeel van daaglikse sproeibemesting teenoor konvensionele besproeiingssisteme te evalueer. Huidige tuinboukundige evaluering van boord-bestuurspraktyke is baie tydrowend. In 'n poging om plantreaksie onder verskillende praktyke te beskryf, het ons besluit om die plantstresvlakke met fisiologiese metodes te vergelyk. Sitrusbome onder daaglikse sproeibemesting, en konvensionele mikro- en drupbesproeiing, is onderskeidelik gemonitor om die plant se stresvlakke vas te stel, soos aangedui deur sapvloei, xileem-waterpotensiaal, stomatale geleiding en chlorofil a f1uoresensie. Die plante onder daaglikse sproeibemesting ondervind lae viakkke van waterstremming, waarskynlik weens hoë grondvogtigheid in die wortelsone. Die bome ondervind wel, soos dié onder konvensionele besproeiing, middagdepressie in stomatale geleiding, hoewel tot 'n mindere mate. Dit blyk asof die groter wortelvolume van mikrospuit besproeide bome die herstel na middagdepressie bespoedig. Produsente word aangeraai om die oggendure optimaal te gebruik deur vroeg te besproei sodat plantproduktiwiteit hoog is terwyl die omgewingsfaktore op hul gunstigste is en wanneer die hoogste fisiologiese aktiwiteit voorkom. Ons het ook die effek van wateronthouding gemeet op die bome wat aangepas is vir daaglikse sproeibemesting. Sodoende is die risiko verbonde aan 'n korttermyn watertekort op hierdie bome ge-evalueer, asook die bruikbaarheid van fisiologiese tegnieke om waterstremming in sitrus te identifiseer. Stomatale geleiding en xileem-waterpotensiaal het waterstremming vroëer aangedui as die ander fisiologiese parameters. Sitrusbome blyk redelik onsensitief te wees teenoor droogtestremming soos gemeet deur sapvloei en chlorofil a fluoresensie. Sapvloei word gebuffer deur boom-kapasitansie, en alhoewel sapvloei gereguleer word deur stomatale geleiding, is dit die atmosferiese toestande (hoofsaaklik dampdruk verskil) wat dit primêr beïnvloed, en nie die grond-water inhoud nie. Omdat bome daagliks sproeibemes word, het hulle meer optimale vlakke van xileemwaterpotensiaal en stomatale geleiding in vergelyking met bome waarvan water weerhou is. Alhoewel daaglikse sproeibemesting die middagdepressie verlaag het, is dit nie daardeur opgelos nie. Oor die typerk van 'n seisoen kan selfs minimale verhogings in stomatale geleiding (en daarmeesaam fotosintese en moontlik groei) en xileem-waterpotensiaal, hoër opbrengste tot gevolg hê.

Made available in DSpace on 2014-06-11T19:28:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-08Bitstream added on 2014-06-13T18:35:03Z : No. of bitstreams: 1 araujo_d_me_botfca.pdf: 601834 bytes, checksum: b2dcd054b52c2b2dc71f5faddbd60de4 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Empresa Privada / Em pomares de citros, o controle químico do agente causal da mancha (ou pinta) preta tem merecido destaque pelo excessivo número de pulverizações, elevando sobremaneira os custos de produção. A busca por melhorias na eficiência das pulverizações e reduções na quantidade dos produtos fitossanitários já tem sido realizada, mas os resultados dessa prática ainda não são consistentes para que possa ser aplicado em escala comercial. Sendo assim, esse trabalho objetivou avaliar a interferência da redução nos volumes de pulverização, no controle da mancha preta em frutos cítricos, bem como o efeito do crescimento dos frutos e da precipitação pluviométrica, sobre a deposição da calda com a aplicação de diferentes volumes. Três experimentos foram conduzidos em pomar comercial com plantas de 16 anos de idade, da variedade Valência e antecedentes comprovados da doença, durante as safras 2005/2006 e 2006/2007. Foram avaliados os depósitos das pulverizações sobre os frutos utilizando-se diferentes volumes de calda (experimento 1), a incidência e severidade da doença em duas épocas distintas (experimento 2), bem como a queda dos frutos do início da maturação até a colheita e a produção (experimento 3). Os tratamentos consistiram de três volumes de calda, 3,5; 4,5 e 8,5 L.planta-1, aplicados pelo turbopulverizador Arbus 2000/Export com ramal especial de bicos, utilizando-se fungicidas e períodos recomendados para o controle da doença, em um total de quatro pulverizações. A quantificação dos depósitos das pulverizações foi por espectrofotometria (íon cobre metálico), após as pulverizações e, da mesma forma, os resíduos ao final dos intervalos entre aplicações. A amostragem dos frutos foi realizada em três alturas (baixo, médio e alto) da planta, na região entre plantas da linha de plantio, com acompanhamento do crescimento dos frutos e... / The chemical control of Guignardia citricarpa has earned prominence for the high number of sprays, increasing the production costs excessively in citrus orchards. The search for improvements in the spray efficiency and reductions in the amount of agrochemicals, already has been accomplished, but the results of that practice are not still consistent for they be applied in commercial scale. For this, the objetives of the present research was to evaluate the interference of reduction spray volumes in citrus black spot control on fruits, as well as, the fruits growth and rainfall effects, in spray deposition with application of different spray volumes. Three experiments were carried out in commercial citrus orchard with proved antecedents of the disease and plants of sixteen years old of the variety Valencia, in 2005/2006 and 2006/2007 agricultural season. The spray deposition on fruits using different spray volumes (experiment 1), the incidence and severity of the disease in two different times (experiment 2), as well as the fruit drop of the beginning fruit maturation until the harvest and the production (experiment 3), were evaluated. The treatments consisted of three spray volumes: 3,5; 4,5 and 8,5 litres.plant-1, applied by one airblast sprayer (model Arbus 2000/Export) with special manifold of hydraulic nozzles and check treatment (without spray) in the second season. Fungicides and recommended periods for ...(Complete abstract click electronic access below)

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Pursuit of innovation projects with the absent of a methodology to follow hampers the development of the software product as its complexity grows since the freedom of its own advancement is confused with the lack of order on it. Traditional and agile methodologies do not adapt to this kind of projects therefore, in this paper we aim to design a model that incorporates characteristics of both of them to get a solution of a need found in society. In this study, we focus on the construction of a mobile application that answer to the lack of a system that integrates pharmaceutical products from different establishment through the appliance of usability concept with the UCD (User centered design) approach. In this case we only detail about four of the seven stages proposed in the model developed with its techniques, tools and activities conducted. Results obtained show that the model proposed achieve the expectative and its use is not limited to just mobile applications but to any kind of software project. / Revisión por pares

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / In this paper, we proposed a wearable technology model to control and monitor hypertension during pregnancy. We enhanced prior models by adding a series of health parameters that could potentially prevent and correct hypertension disorders in pregnancy. Our proposed model also emphasizes the application of real-time data analysis for the healthcare organization. In this process, we also assessed the current technologies and systems applications offered in the market. The model consists of four phases: 1. The health parameters of the patient are collected through a wearable device; 2. The data is received by a mobile application; 3. The data is stored in a cloud database; 4. The data is analyzed on real-time using a data analytics application. The model was validated and piloted in a public hospital in Lima, Peru. The preliminary results showed an increased-on number of controlled patients by 11% and a reduction of maternal deaths by 7%, among other relevant health factors that allowed healthcare providers to take corrective and preventive actions. / Revisión por pares

Cardiovascular diseases which include high blood pressure, coronary heart diseases, heart failure, stroke and peripheral arterial diseases (PAD) affect one out of three American adults or 105 million people. By 2030, the prevalence of cardiovascular disease is estimated to rise 10 percent to more than 40 percent of American adults, or 116 million people. Approximately 8 million people in the United States have PAD, including 12-20% of individuals older than age 60. The main reason of PAD is obstruction of blood flow through lower extremities causing Atherosclerosis. The major artery affected in the lower extremities due to PAD is superficial femoral artery (SFA). Huge numbers of clinical procedures like superficial femoral artery stenting, balloon angioplasty, and percutaneous transluminal intervention are done to treat the disease. Thorough in vitro (biological phenomena made to occur outside the human body) testing of this kind should reduce the risk of in vivo (biological phenomena occurring inside the human body) stent failure and thus lead to increased survivability for patients suffering with cardiovascular diseases and PAD. It has been recognized that a metal subjected to a repetitive or fluctuating stress will fail at a stress much lower than that required to cause failure on a single application of load. As per literature review, typically SFA stents survive no more than 12-18 months until the first fracture is detected in MRI. There was a need of a customized designed device such that it would simulate realistic blood pressure conditions and test the capacity the SFA stents. Commercially, the stents are tested under accelerated cyclic loading conditions at different frequencies for longer cycle periods. In order to demonstrate how stents perform once deployed into an artery, a testing device was required which will simulate arterial blood pressure variations and compressive loads over artery as close as possible to human body. The stent tester documented in this report is capable of subjecting a stent to appropriate physiological loading by deploying it in a simulated vessel and subjecting it to external compression. Loading of this kind was performed at frequencies at 60 Hz and, as such, simulating one million heartbeats of artery pulsation. The primary purpose of this thesis was to successfully design stent tester which cycles artificial fluid simulating blood pressure in arteries and superimposing cyclic compression of stent deployed in an artificial artery. The goal was to obtain a test machine that allows for a cost effective testing of cardiovascular and peripheral stents. Another goal was to externally compress the arterial wall subjected to compressive load with the help of an air controlled mechanical piston attached with load cell assembly. The load cell measures the amount of load applied over the silicone tubing. The design of the device contains two peristaltic pumps which alternate pressure every second by pumping distilled water via plastic tubing. The stent was crimped with the guide wire catheter and deployed in the silicone artery (diameter 11mm O.D) from Dynatek labs. Wall and bridge stents (Medtronic, Schneider Inc.) 10 x 39 mm were used for testing with and without external load. Industrial pressure transducer S-10 (Wika Instruments Corporation) ranging from 0-5 PSI (0-259mmHg) is used to monitor the pressure in the artificial artery. The pressure transducer is connected to the data logger (Omega om320) which serially communicates with computer. The silicon mock test artery was 20cm long so that stents used in various arterial interventions can be tested. The silicon artery has primary advantages over rubber latex artery which are clarity and close resemblance to human artery and durable (ideal for long term durability tests). Preliminary results from literature review show that stent materials, based on its mechanical properties survive for more than one million heartbeats. To demonstrate the capacity of current design a nitinol stent was tested under physiological conditions at 60Hz frequency. A load of 980 grams for 2001 - 5000 heartbeats, 1.98 kg for 5001 - 10000 heartbeats, 4.25 kg for 10001 - 25000 heartbeats and 6.54 kg for 25001 - 50000 heartbeats was applied over the artificial artery. The mechanical piston with load cell assembly was allowed to externally compress the artificial artery. Partial functionality of device was demonstrated by running it for one million heartbeats and 48000 compressive cycles. The device was successfully designed and has the capacity to cycle artificial fluid simulating blood pressure changes in arteries and have demonstrated the ability to test any type of stents. The device was designed efficient which was simulated in an acceptable pressure range as compared to human blood pressure and allow for compression of stent in a cyclic testing pattern. The system was maintained to as close as between diastolic value of 76mmHg to diastolic 122mmHg pressure range. The device was run for about one million heartbeats and it was observed that the NiTi stent successfully survived. The stent was observed visually with a magnifying glass for any cracks or failure at intervals of 500, 1000, 2000, 5000, 10000, 25000, 50000 and one million heartbeats respectively. After running the device for one week at a frequency of 60Hz, no fractures on the stent were visually observed. However, the stent was deformed from the center. Data analysis showed that the mean diastolic and systolic pressure measurements for intervals with no load were found to be statistically significant i.e. in acceptable range. However, the device design lacks stability due to various reasons like device operates in an open looped system, has bubbles in the artificial artery which might be producing varying pressure values and variation in applying load. The device was partly unable to simulate arterial blood pressure changes under no loading conditions. Efforts are being made to improve the design of the device to make it realistic simulation of variation in arterial blood pressure for long term durable testing of the stents.

This thesis was requested by Solution Xperts in Linköping and is an evaluation of the software BizTalk360, which is a add-on to the very well known application integration software BizTalk Server. One problem that many face with BizTalk Server is how to handle the post-implementation operations of their implementation. Referring to such factors as monitoring and security for instance. The built-in tools are very limited and lack a variety of functions that are very desirable. BizTalk360 tries to solve this. In order to evaluate the value that BizTalk360 brings to its users, two factors were taken into account. How important are the functions provided for the company? And how difficult would these be to implement independently?. After testing the BizTalk360 core functions and features and also implementing a representative function of BizTalk360, everything learnt were presented to group of experienced BizTalk Sever developers in order to receive estimates regarding their individual importance and theoretical implementation time. The importance of the functions proved quite minor. The platform offers a lot of smart solutions to various problems but these wont see enough use to justify the cost. The difficulty of implementing a similar platform were also estimated to be quite low, only time consuming. Estimated to take (through average) 653 man hours.