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Tor is a network designed for low-latency anonymous communications. Tor clients form circuits through relays that are listed in a public directory, and then relay their encrypted traffic through these circuits. This indirection makes it difficult for a local adversary to determine with whom a particular Tor user is communicating. Tor may also be used to circumvent regional Internet censorship, since the final hop of a user's connection can be in a different country. In response, some local adversaries restrict access to Tor by blocking each of the publicly listed relays. To deal with such an adversary, Tor uses bridges, which are unlisted relays that can be used as alternative entry points into the Tor network. Unfortunately, issues with Tor's bridge implementation make it easy to discover large numbers of bridges. This makes bridges easy to block. Also, an adversary that hoards this information may use it to determine when each bridge is online over time. If a bridge operator also browses with Tor on the same machine, this information may be sufficient to deanonymize him. We present BridgeSPA as a method to mitigate these issues. A client using BridgeSPA relies on innocuous single packet authorization (SPA) to present a time-limited key to a bridge. Before this authorization takes place, the bridge will not reveal whether it is online. We have implemented BridgeSPA as a working proof-of-concept for GNU/Linux systems. The implementation is available under a free licence. We have integrated our implementation to work in an OpenWRT environment. This enables BridgeSPA support for any client behind a deployed BridgeSPA OpenWRT router, no matter which operating system they are running.

Tor is a network designed for low-latency anonymous communications. Tor clients form circuits through relays that are listed in a public directory, and then relay their encrypted traffic through these circuits. This indirection makes it difficult for a local adversary to determine with whom a particular Tor user is communicating. Tor may also be used to circumvent regional Internet censorship, since the final hop of a user's connection can be in a different country. In response, some local adversaries restrict access to Tor by blocking each of the publicly listed relays. To deal with such an adversary, Tor uses bridges, which are unlisted relays that can be used as alternative entry points into the Tor network. Unfortunately, issues with Tor's bridge implementation make it easy to discover large numbers of bridges. This makes bridges easy to block. Also, an adversary that hoards this information may use it to determine when each bridge is online over time. If a bridge operator also browses with Tor on the same machine, this information may be sufficient to deanonymize him. We present BridgeSPA as a method to mitigate these issues. A client using BridgeSPA relies on innocuous single packet authorization (SPA) to present a time-limited key to a bridge. Before this authorization takes place, the bridge will not reveal whether it is online. We have implemented BridgeSPA as a working proof-of-concept for GNU/Linux systems. The implementation is available under a free licence. We have integrated our implementation to work in an OpenWRT environment. This enables BridgeSPA support for any client behind a deployed BridgeSPA OpenWRT router, no matter which operating system they are running.

<p>  </p> <p>The engine is the heart of the vehicle; any problems with this component will cause significant damage and may even result in the car being junked. The engine repair cost is enormous, and there is no guarantee that the existing engine will be repaired or replaced. Fault diagnosis in engines is critical; there have been numerous techniques and tools used for fault diagnosis in this revolutionary world, which require some extra cost to detect and still cannot detect faults such as knocking. The engine can have several problems but knocking is the major issue that blows up the engine and results in the breakdown of the vehicle. Our research focuses on this key issue which not only costs thousands of dollars but also results in waste. According to experts, at a very early stage, knocking can be detected by human senses, either visually or audibly. The most noticeable feature in detecting engine faults is the knocking sound.  Artificial intelligence deep learning neural networks are well known for their ability to simulate humans; we can utilize this domain to train the networks on sound to detect engine knocking. Many neural networks have been designed for various purposes, one of which is classification. The best widely used and reliable network is the convolution neural network (CNN) which takes input as images and classifies them respectively. Engine sounds have been collected from Google’s Machine Perception research. Our research shows that a prominent feature in building these networks is data. Understanding data and making the most of it is central to data science. A better model is created by meaningful data, not just by designing a complex network. We have used a new algorithmic method of extracting sound and feeding it into all variants of CNN, which we call dependent vehicle sound extraction, in which we use fast Fourier transform (FFT), short-time Fourier transform (STFT), and Mel-frequency cepstral coefficients (MFCCs) for processing input sound signals. We validated the utilization of deep learning networks with a unique dependent vehicle feature extraction technique to detect engine knocking with accurate classification.</p>

Ideas for ways to use textiles and other materials as body coverings, or as a form of apparel decoration, as well as protection, continued to evolve throughout history. More complex ideas and outcomes developed with the advent of weaving, and rectangular shapes were draped in folds, tied, or wrapped around the body. An accepted practice in the apparel industry is seeking inspiration for ideas from a variety of people, places, and things. This practice of seeking inspiration from the environment leads to the question of whether copying is inherent within the apparel industry. History of costume research and study indicate that it is generally accepted that people wear differing apparel for each season of the year, with some repeat, or copying, in the same season in subsequent years. The terms counterfeiting, knocking-off, and copying are often used interchangeably, but further exploration of the terms show they are not the same. Counterfeiting has become, and remains a hot topic in the apparel industry, particularly in product development. Some designers have begun to challenge and demand their work be protected in some manner such as copyrights, trademarks, or patents. Questions and concerns abound among product developers. This study was exploratory in nature, seeking a definition, and identifying a specific point in the product development process, when a certain activity (i.e., copying) is more likely to be performed. Therefore, qualitative methods were used to achieve the objectives of the research. This research took a cross-sectional approach within a qualitative design study when selecting the participants. The cross-sections for the participants of this study were those participants in positions of direct influence on apparel product development. Analyzing the perceptions of the participants from the cross-sections in detail, inferences were made about the industry definition and method of copying, time of occurrence, and those most likely involved in decision making. The instrument for the study was an online survey with open-ended questions and fixed-response questions. Of the 20 participants, 11 accessed the survey with 10 choosing to participate. While some degree of similarity was observed in several of the definitions of copying, such as taking existing products to create new products, there was distinction when participants used phrases such as copying 'without changing anything' to 'copying the idea and concept.' Participants' definition of knocking-off can be summarized as a copy with variation in price point. Participants noted that the process of counterfeiting was an unauthorized or illegal copy of a product and often included copying labels or logos. Key reasons for copying products were reported as following trends and speed to market. / Ph. D.

É analisado o desempenho de um motor de ignição por compressão turboalimentado por uma mistura temária de combustíveis (diesel, biodiesel e etanol) através do comportamento do motor operando com um combustível principal, o qual poderá ser o diesel ou biodiesel ou misturas destes dois, com e sem sua substituição parcial por etanol no coletor de admissão. A análise do desempenho é feita através das curvas de torque, potência, rendimento térmico e consumo específico de combustível. A combustão do motor é estudada através de um programa simulador que utiliza um modelo zero-dimensional, que avalia a taxa de liberação de calor durante a combustão e tem como dado de entrada a curva de evolução da pressão dentro do cilindro. Faz-se a identificação e quantificação do fenômeno da detonação utilizando análise espectral, através do sinal de pressão da câmara de combustão, para o motor operando com diversas misturas combustíveis. São analisadas também as emissões gasosas do motor com as misturas, e a viabilidade técnica do uso de biodiesel em motores de ignição por compressão, além de um estudo geral sobre o uso do éster de óleo vegetal. / The performance of a three-fuel system (diesel, biodiesel and ethanol) turbocharged compression-ignition engine is analyzed, through the engine behavior supplied by mixtures of diesel or biodiesel or mixtures of these fuels with ethanol in the intake manifold. The performance analysis is made by torque, power, specific fuel consumption and thermal efficiency curves. The engine combustion is studied by a simulator program that uses a zero-dimensional model, that evaluate the heat release rate during the combustion and it has as input data the pressure evolution curves inside the cylinder. The knocking phenomenon is studied by spectral analysis. The pollutant gases emissions and the technical viability of the utilization of biodiesel also are analyzed, beyond a general study about of vegetal oil ester.

É analisado o desempenho de um motor de ignição por compressão turboalimentado por uma mistura temária de combustíveis (diesel, biodiesel e etanol) através do comportamento do motor operando com um combustível principal, o qual poderá ser o diesel ou biodiesel ou misturas destes dois, com e sem sua substituição parcial por etanol no coletor de admissão. A análise do desempenho é feita através das curvas de torque, potência, rendimento térmico e consumo específico de combustível. A combustão do motor é estudada através de um programa simulador que utiliza um modelo zero-dimensional, que avalia a taxa de liberação de calor durante a combustão e tem como dado de entrada a curva de evolução da pressão dentro do cilindro. Faz-se a identificação e quantificação do fenômeno da detonação utilizando análise espectral, através do sinal de pressão da câmara de combustão, para o motor operando com diversas misturas combustíveis. São analisadas também as emissões gasosas do motor com as misturas, e a viabilidade técnica do uso de biodiesel em motores de ignição por compressão, além de um estudo geral sobre o uso do éster de óleo vegetal. / The performance of a three-fuel system (diesel, biodiesel and ethanol) turbocharged compression-ignition engine is analyzed, through the engine behavior supplied by mixtures of diesel or biodiesel or mixtures of these fuels with ethanol in the intake manifold. The performance analysis is made by torque, power, specific fuel consumption and thermal efficiency curves. The engine combustion is studied by a simulator program that uses a zero-dimensional model, that evaluate the heat release rate during the combustion and it has as input data the pressure evolution curves inside the cylinder. The knocking phenomenon is studied by spectral analysis. The pollutant gases emissions and the technical viability of the utilization of biodiesel also are analyzed, beyond a general study about of vegetal oil ester.

Port-knocking is a security mechanism used in computer systems to hide available network services. Its operation relies on a drop policy firewall setting in order to make impossible for port-scanning attacks to occur. This project researches the impact of implementing such a software solution. Furthermore, it looks into the behavior of three chosen implementations and make conclusions on the benefits and disadvantages that they bring. In addition, the surrounding implications related to both user and administrator are explored. This thesis includes tests on the resource consumption of the implementations as well as records of the added delay of using the mechanism when initiating a SSH session. There has not been such research performed in this field and the results of it could be beneficial to those who are involved in computer science and network security in particular. Finally, the product of this study state that port-knocking is overlooked and has great benefits in preventing zero-day exploits and hacker tools relying on exposed network services.

Recently, some new technologies (e.g., downsizing, turbocharging) have been widely used in spark-ignition (SI) engines to achieve higher efficiencies and less emissions. However, the improved power density and in-cylinder pressure promote more engine knock, causing violent pressure oscillations and threatening engine integrity. Therefore, it is imperative to study engine knocking combustion more than ever; In-depth understandings of knock mechanism and characteristics are of utmost importance for controlling knock. With this emphasis, this thesis implements systematic studies to bridge the gap between knocking combustion characteristics and knock suppressing strategies. To investigate knock with optical and laser diagnostics, an optical compression-ignition (CI) engine was modified to operate under SI mode. A home-made metal liner with multiple spark plugs was used to trigger more controllable knock events via different spark strategies. Up to six pressure sensors were installed to collect the pressure signals from different sides. Next, the relationships between in-cylinder pressure, knock intensity, pressure fluctuation, heat release, and measurement location are analyzed to study the knock mechanism, influential factors, and measurement methods. The findings indicate a trade-off between the mass fraction and temperature of end-gas. The effects of compression ratio and fuel octane number are also explored. Moreover, the multichannel pressure monitoring is synchronized with high-speed imaging to investigate the flame propagation and knock development processes regarding the different spark strategies. The results give insights into the in-cylinder temperature inhomogeneity and how it affects the spatial distribution of auto-ignition sites. Furthermore, a new method is proposed to detect the local pressure fluctuations by setting a series of virtual flame monitors instead of pressure sensors. The results validate that this method provides a convenient and reliable way to study knock oscillations. Finally, this study presents a hydraulically actuated VCR (variable compression ratio) piston design to address knock challenges. The numerical simulation results show this VCR piston has a good adaptability and could help achieve high engine efficiencies, while keeping reasonable peak pressure to avoid heavy knock at high loads. However, more analysis work still needs to be implemented on its practical applications, e.g., the thermal stress and frictions under different operating conditions.

Sound is an important aspect of storytelling. Previous studies have investigated the emotional perceptions of knocking sounds, in relation to the colour and material of the door. This study will build on these projects and investigate two new visual factors, colour grading and the speed at which a door opens, to determine how they affect emotional perception in isolation, and then how they interfere with five expressive knocking sounds. This was done by conducting four experiments. The first two experiments investigated the emotional perception of the visual factors. In the last two experiments, the visual factors were combined with the expressive knocking sounds, in order to investigate how the conveyed emotions of these visual factors interfered with the perceived emotions of the knocking sounds. The results showed that the knocking sounds had the strongest influence over the overall perceived emotion. However, the colour gradings were able to influence and interfere with the perceived emotion of the knocking sounds, while the door opening speeds did not have an effect. / Ljud är en viktig del i historieberättande. Tidigare studier har utforskat den känslomässiga uppfattningen av ljud i form av knackningsljud, samt hur dörrens färg och material påverkar den uppfattningen. Den här studien bygger på dessa projekt och utforskar två andra visuella faktorer i form av färgsättning (colour grading) och hastigheten en dörr öppnas med. Den känslomässiga uppfattningen av dessa faktorer undersöks, samt hur de påverkar fem knackningsljud med avsedda känslor. Det här undersöktes med hjälp av fyra experiment. I de två första experimenten undersöktes den känslomässiga uppfattningen av de två visuella faktorerna enskilt. I de två sista experimenten, kombinerades de visuella faktorerna seperat med de fem knackningsljuden. Här undersöktes det hur de känslorna som förmedlades av de visuella faktorerna påverkade de förmedlade känslorna av knackningsljuden. Resultatet visade på att knackningsljuden hade mest influens över den övergripande uppfattade känslan. Däremot så influerade och påverkade färgsättningen den uppfattade känslan av knackningsljuden, medan dörrhastigheten inte gjorde det.