Tor is a popular anonymity-preserving network, consisting of routers run by volunteers all around the world. It protects Internet users’ privacy by relaying their network traffic through a series of routers, thus concealing the linkage between the sender and the recipient. Despite the advantage of Tor’s anonymizing capabilities, it also brings extra latency, which discourages more users from joining the network. One of the factors that causes the latency lies in Tor’s circuit scheduling algorithm, which allows busy circuits to crowd out bursty circuits. In this work, we propose and implement a more advanced scheduling algorithm which treats circuits differently, based on their recent activity. In this way, bursty circuits such as those used for web browsing can gain higher priority over busy ones such as used for bulk transfer; the performance for most activities over Tor is improved, while minimal overhead is incurred. Our algorithm has been incorporated into the latest build of Tor.

Orientador : Theo Guenter Kieckbusch / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos e Agricola / Made available in DSpace on 2018-07-15T11:47:25Z (GMT). No. of bitstreams: 1 Finzer_JoseRobertoDelalibera_M.pdf: 30702047 bytes, checksum: 3a3df374efcd7bfd961d66463ff002c7 (MD5) Previous issue date: 1984 / Resumo: Desenvolveu-se um protótipo de secador de leito vibro-fluidizado, que foi testado na desidratação de anéis de cebola. O e-quipamento reduz o tempo de secagem de cebola e melhora a qualidade do produto desidratado, quando comparado com secadores conven-cionais.Foram determinados os parâmetros ótimos de vibração, visan-do consumir um mínimo de energia. Deu-se ênfase especial à descrição do comportamento fluido-dinâmico do leito vibro-fluidizado.Verificou-se a influência das condições do ar e da cebola na secagem em leito estático e vibro-fluidizado. Os parâmetros investigados foram: velocidade e temperatura do ar, carga de cebola no leito e dimensões das fatias de cebola. Foram definidas as me-lhores condições de operação, visando principalmente um produto uniforme em forma e no conteúdo de umidade e obtido com reduzido tempo de secagem. Efetuou-se um estudo sensorial com a cebola reconstituída a fim de delimitar as melhores opções de operação, mantendo um com promisso de uma qualidade aceitável. Ensaios de reconstituição revelaram que a cebola desidratada sob influência vibracional, apresenta maior velocidade de rehidratação do que a obtida em leito estático.Realizou-se uma análise matemática utilizando um modelo que relaciona a umidade residual da cebola com a difusividade. As e- equações obtidas permitem realizar simulação de secagem em diferentes condições de operação / Abstract: A prototype of a vibro-fluidized bed dryer was developed and applied to the dehydration of onion rings. Compared to conventional drying methods, this equipment reduces the drying time and improves the quality of the final product.The best vibrating parameters, in terms of energy consumption were determined. Special attention is given to the destription of the fluid dynamic behavior óf the vibro-fluidized bed. The influence of the conditions of the drying air and of the onions were determined. The parameters investigated were: air velocity and air temperature, onion-bed load and dimensions of the chopped onions. The best operation conditions were defined, seeking a product uniform in shape and in water content, obtained with a minimum drying time. Sensorial evaluations were made on reconstituted onions in order to establish the options that ensure an acceptable quality. Reconstitution tests revealed that the onion produced under vibrations showed higher rehydration rate than the one obtained in static bed. A mathematical analysis was made, making use of a diffúsional -model for water transport. The equations obtained can be used to simulate drying under different conditions / Mestrado / Mestre em Engenharia de Alimentos

Anonymity on the internet is becoming a actuall issue nowadays. There are several tools, that can be used to monitor user's activity and it can lead to lose privacy of users. The aim of this master's thesis is to describe different ways of working anonymous systems, especially the method called Onion Routing. The introduction of this work is devoted to the description of this method together with asymmetric cryptosystem RSA. The second part belongs to basics of socket programming and to the implementation of anonymous system in programming language C++. The final part is focussed on analysis of system in terms of security and time complexity. The conditions of anonymity and decentralization are accomplished. There is no presence of central server in the system and the management is handled by signalling messages.

Yes / Uniform onion micelles formed from up to ten nano-structured polymer layers were produced by the aqueous self-assembly of highly-branched copolymers. Highly-branched poly(alkyl methacrylate)s were chain extended with poly(acrylic acid) in a two-step reversible addition–fragmentation chain transfer-self-condensing vinyl polymerization (RAFT-SCVP) in solution. The resulting polymers were dispersed into water from oxolane (THF) using a self-organized precipitation-like method and the self-assembled particles were studied by phase-analysis light scattering, small-angle neutron scattering, and electron microscopy techniques. The relative hydrophobicity of the blocks was varied by changing the alkyl methacrylate (methyl, butyl, or lauryl) and this was found to affect the morphology of the particles. Only the poly(butyl methacrylate)-containing macromolecule formed an onion micelle structure. The formation of this morphology was observed to depend on: the evaporation of the good solvent (THF) during the self assembly process causing kinetic trapping of structures; the pH of the aqueous phase; and also on the ratio of hydrophobic to hydrophilic segments within the copolymer. The lamellar structure could be removed by annealing the dispersion above the glass transition temperature of the poly(butyl methacrylate). To exemplify how these onion micelles can be used to encapsulate and release an active compound, a dye, rhodamine B (Rh B), was encapsulated and released. The release behaviour was dependent on the morphology of the particles. Particles formed containing the poly(methyl methacrylate) or poly (lauryl methacrylate) core did not form onions and although these materials absorbed Rh B, it was continuously released at room temperature. On the other hand, the lamellar structure formed from branchpoly( butyl methacrylate)-[poly(butyl methacrylate)-block-poly(acrylic acid)] allowed for encapsulation of approximately 45% of the dye, without release, until heating disrupted the lamellar structure. / EPSRC and Domino UK Ltd for a Nanotechnology KTN CASE studentship to support SLC, Experiments at the ISIS Pulsed Neutron and Muon Source were supported by a beam time allocation from the Science and Technology Facilities Council (experiment numbers RB1220108 and RB1320167).

V tejto práci sumarizujeme aktuálny výskum protokolov z rodiny Proof-of-Stake ako napr. Algorand, Tendermint a LaKSA. Analyzovali sme ich funkcionalitu a tiež ich problémy. V rámci výskumu sme implementovali a novy protokol z rodiny Dôkaz-Podielom, ktorý rieši nájdené problémy ako priepustnosť, škálovatelnosť a bezpečnosť.

Studies were carried out at the Safford Agricultural Center using some soil amendments as anti-crusting agents. The results are promising in terms of improved stands on soils subject to crusting. Additional research is needed in order to determine proper rates which will reduce crusting without being toxic to the emerging seedlings.

Tyrimai, tiriant svogūnų netikrosios miltligės plitimą įtakojančius veiksnius, atlikti ūkininko Lino Šateikos ūkyje, Daugėlaičių k., Meškuičių sen., Šiaulių raj. 2005-2008 metais. Tirta meteorologinių sąlygų, svogūnų veislių (hibridų) („Sherpa F1“ bei „Renate F1“) ir fungicidų (Penncozeb 75 DG bei Dithane NT 75% g.) įtaka svogūnų netikrajai miltligei. Lauko bandymo tyrimų metu nustatyta, kad temperatūra ir drėgmė – svarbiausieji veiksniai svogūnų netikrajai miltligei plisti ir vystytis per visą augalų vegetaciją. Šią ligą plisti skatino gausūs krituliai (88 mm) bei 17,4 ºC vidutinė birželio- rugpjūčio mėnesių oro temperatūra. Penncozeb 75 DG efektyvumas per 2005-2008 metus „Sherpa F1“ veislės svogūnų pasėlyje buvo vidutiniškai 3,2 proc. punkto didesnis negu Dithane NT 75% g., o „Renate F1“ veislės svogūnuose – 2,9 proc. punkto didesnis, lyginant su Dithane NT 75% g. Lyginant veislių įtaką svogūnų derliui, nustatyta, jog atsparesnė svogūnų netikrajai miltligei yra „Renate F1“. Šios veislės svogūnų pasėliuose per 2005-2008 metus yra gautas vidutiniškai 6,2 t didesnis derlius nei „Sherpa F1“ svogūnų pasėliuose. Atlikus ekonominį vertinimą, nustatyta, jog didžiausią papildomų gamybos išlaidų našumą sukuria „Renate F1“ veislės svogūnų, apdorotas fungicidu Penncozeb 75 DG, pasėlis. / Researches in order to analyze the influencing factors in spread of onion downy mildew were carried out in farmer‘s Linas Šateika farm, Daugėlaičių k., Meškuičių sen., Šiaulių raj., in year 2005-2008. There were studied the influence of meteorological conditions, onion species (hybrids) (“Sherpa F1” and “Renate F1”) and fungicides (Penncozeb 75DG and Dithane NT 75% g.) on onion downy mildew. At the field experiment were defined, that temperature and moisture are the most important factors in onion downy mildew spreading and progressing during all growing season. This disease was stimulated by pluvious precipitations (88 mm) and 17,4 ºC air temperature in June - August. The effectiveness of Penncozeb 75 DG during the year 2005-2008 in “Sherpa F1” crops was on the average 3,2 % more than Dithane NT 75%, and in “Renate F1” – 2,9 % more. In comparing the influence of species on onion harvest, there were determined, that “Renate F1” is more resistant to onion downy mildew. In the onion crops of “Renate F1” during years 2005-2008, there were ingathered on the average 6,2 t more than in crops of “Sherpa F1”. In carrying out the economical evaluation, there were identified, that the most extra efficiency of production costs is obtainable in “Renate F1” crops with Penncozeb 75 DG.

Due to the relatively small amount of work concerning radiation, it was thought feasible to use ionizing radiation as a tool to study the relationship between water and salt flux in isolated root systems. Moreover, the more quantitative potometric method lends itself well to such a study, since the two processes can be followed simultaneously. the aims of this study, therefore, were 1) to determine effects of X-irradiation on water, calcium and potassium flux in excised onion roots; 2) to determine the dose levels required for producing permeability changes; 3) to investigate the nature of radiation damage to root systems; and 4) to attempt to shed light on the relation between water transport and ion movement in root systems.

O potencial fisiológico de sementes, determinado pela germinação e vigor, é diretamente responsável pelo desempenho das sementes em campo, podendo até se refletir na produtividade de diversas espécies de hortaliças de importância econômica. Diante disto, o presente trabalho teve como objetivo avaliar a eficiência de diferentes métodos para determinação do potencial fisiológico de sementes de cebola (Allium cepa L.), visando destacar procedimentos adequados para utilização em programas de controle de qualidade; procurou-se, também, verificar a relação dos resultados obtidos em laboratório com a emergência das plântulas e o desempenho das plantas em campo. Para tanto, utilizaram-se seis lotes de sementes dos cultivares Aurora e Petroline, avaliados, em laboratório, quanto ao grau de umidade, germinação e vigor (primeira contagem de germinação, classificação do vigor de plântulas, condutividade elétrica, frio sem terra, envelhecimento acelerado tradicional e com solução salina e deterioração controlada). O desempenho das plantas foi verificado em ensaios de campo, utilizando-se dois sistemas de cultivo: semeadura direta e transplante de mudas; durante o desenvolvimento das plantas avaliaram-se, periodicamente, a altura, o diâmetro na região do colo e a massa de matéria seca das plantas. Após a colheita, determinou-se o rendimento final e efetuou-se a avaliação comercial dos bulbos. Concluiu-se que os testes de envelhecimento acelerado com solução salina (41ºC/72h), de deterioração controlada (ajuste do grau de umidade das sementes para 24% de água/45ºC/24h) e de classificação do vigor de plântulas, são considerados eficientes para avaliação do potencial fisiológico de sementes de cebola. As relações entre o vigor de sementes de cebola e o desempenho das plantas manifestam-se apenas durante a fase inicial do desenvolvimento da cultura, principalmente quando as diferenças entre o potencial fisiológico dos lotes são mais acentuadas, mas não afetam diretamente a produção de bulbos. / Research has emphasized the relationship of laboratory germination and vigor to seedling emergence and stand establishment. In contrast, information relating seed vigor to plant performance is less available. This study was conducted to identify reliable procedures to rank onion ( Allium cepa L.) seed lots according to their physiological potential and to select the most adequate procedures to be used in quality control programs. In addition, it was verified whether the differences in seed vigor influence plant performance in field conditions. Six seed lots of cultivars Aurora and Petroline were evaluated in laboratory for germination and vigor (first count, seedling vigor classification, electrical conductivity, cold test, traditional and saturated salt accelerated aging and controlled deterioration). Field experiments to detect differences in plant development were performed by direct sowing and transplant systems; after the determination of seedling emergence, plant vegetative development was evaluated by plant height, pseudo stem width and dry matter accumulation measurements. After harvest, the bulbs commercial classification and yield evaluation were provided. It was concluded that saturated salt accelerated aging (41ºC/72h), controlled deterioration (24% of water/45ºC/24h) and seedling vigor classification tests were the best procedures to assess the physiological potential of onion seeds. The initial plant development as measured by plant height and dry matter accumulation was affected by seed vigor mainly when the differences of seed physiological potential became wider as a result of the storage period. Influence of seed vigor did not persist during plant vegetative growth and yield was not related to seed vigor level. It was therefore concluded that the use of high vigor seed lots is justified to ensure adequate stand establishment under different environmental conditions.

O potencial fisiológico de sementes, determinado pela germinação e vigor, é diretamente responsável pelo desempenho das sementes em campo, podendo até se refletir na produtividade de diversas espécies de hortaliças de importância econômica. Diante disto, o presente trabalho teve como objetivo avaliar a eficiência de diferentes métodos para determinação do potencial fisiológico de sementes de cebola (Allium cepa L.), visando destacar procedimentos adequados para utilização em programas de controle de qualidade; procurou-se, também, verificar a relação dos resultados obtidos em laboratório com a emergência das plântulas e o desempenho das plantas em campo. Para tanto, utilizaram-se seis lotes de sementes dos cultivares Aurora e Petroline, avaliados, em laboratório, quanto ao grau de umidade, germinação e vigor (primeira contagem de germinação, classificação do vigor de plântulas, condutividade elétrica, frio sem terra, envelhecimento acelerado tradicional e com solução salina e deterioração controlada). O desempenho das plantas foi verificado em ensaios de campo, utilizando-se dois sistemas de cultivo: semeadura direta e transplante de mudas; durante o desenvolvimento das plantas avaliaram-se, periodicamente, a altura, o diâmetro na região do colo e a massa de matéria seca das plantas. Após a colheita, determinou-se o rendimento final e efetuou-se a avaliação comercial dos bulbos. Concluiu-se que os testes de envelhecimento acelerado com solução salina (41ºC/72h), de deterioração controlada (ajuste do grau de umidade das sementes para 24% de água/45ºC/24h) e de classificação do vigor de plântulas, são considerados eficientes para avaliação do potencial fisiológico de sementes de cebola. As relações entre o vigor de sementes de cebola e o desempenho das plantas manifestam-se apenas durante a fase inicial do desenvolvimento da cultura, principalmente quando as diferenças entre o potencial fisiológico dos lotes são mais acentuadas, mas não afetam diretamente a produção de bulbos. / Research has emphasized the relationship of laboratory germination and vigor to seedling emergence and stand establishment. In contrast, information relating seed vigor to plant performance is less available. This study was conducted to identify reliable procedures to rank onion ( Allium cepa L.) seed lots according to their physiological potential and to select the most adequate procedures to be used in quality control programs. In addition, it was verified whether the differences in seed vigor influence plant performance in field conditions. Six seed lots of cultivars Aurora and Petroline were evaluated in laboratory for germination and vigor (first count, seedling vigor classification, electrical conductivity, cold test, traditional and saturated salt accelerated aging and controlled deterioration). Field experiments to detect differences in plant development were performed by direct sowing and transplant systems; after the determination of seedling emergence, plant vegetative development was evaluated by plant height, pseudo stem width and dry matter accumulation measurements. After harvest, the bulbs commercial classification and yield evaluation were provided. It was concluded that saturated salt accelerated aging (41ºC/72h), controlled deterioration (24% of water/45ºC/24h) and seedling vigor classification tests were the best procedures to assess the physiological potential of onion seeds. The initial plant development as measured by plant height and dry matter accumulation was affected by seed vigor mainly when the differences of seed physiological potential became wider as a result of the storage period. Influence of seed vigor did not persist during plant vegetative growth and yield was not related to seed vigor level. It was therefore concluded that the use of high vigor seed lots is justified to ensure adequate stand establishment under different environmental conditions.