228 research outputs found

    A Correlation Framework for Continuous User Authentication Using Data Mining

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    Merged with duplicate records: 10026.1/572, 10026.1/334 and 10026.1/724 on 01.02.2017 by CS (TIS)The increasing security breaches revealed in recent surveys and security threats reported in the media reaffirms the lack of current security measures in IT systems. While most reported work in this area has focussed on enhancing the initial login stage in order to counteract against unauthorised access, there is still a problem detecting when an intruder has compromised the front line controls. This could pose a senous threat since any subsequent indicator of an intrusion in progress could be quite subtle and may remain hidden to the casual observer. Having passed the frontline controls and having the appropriate access privileges, the intruder may be in the position to do virtually anything without further challenge. This has caused interest'in the concept of continuous authentication, which inevitably involves the analysis of vast amounts of data. The primary objective of the research is to develop and evaluate a suitable correlation engine in order to automate the processes involved in authenticating and monitoring users in a networked system environment. The aim is to further develop the Anoinaly Detection module previously illustrated in a PhD thesis [I] as part of the conceptual architecture of an Intrusion Monitoring System (IMS) framework

    The synthesis and evaluation of small organic molecules as cholecystokinin antagonists

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    Cholecystokinin (CCK) is a peptide hormone, present in the alimentary and the CNS. It is the most abundant peptide in the brain. CCK has been implicated in a number of disorders. The link between CCK and anxiety was the basis for this research. A comprehensive discussion on the many types of CCK receptor antagonists is included. For the drug discovery process, a number of synthetic approaches have been investigated and alternative chemical approaches developed. 1,4-Benzodiazepine analogues were prepared, with substitutents In the 1,2 & 3- position of the benzodiazepine scaffold varied, and substituted 3-anilino benzodiazepines exhibited the greatest in vitro activity towards the CCKA receptor subtype. Through extensive screening, pyrazolinone-ureido derivatives were identified, optimised, SAR studied and re-screened. A comprehensive in vivo study on the most active analogue is included, which has a number of common structural features with L-36S, 260 including activity. Pyrazolinone-amide derivatives, bearing the tryptophan moiety were equally active. A number of existing and novel furan- 2(SH)-one building blocks were prepared, from which a selected mini-library of 4- amino-substituted furan-2(SH)-ones were prepared and evaluated. All synthesised compounds were evaluated in a CCK radiolabelled binding assay (CCKA & CCKB), with compounds demonstrating receptor selectivity and lead structures being discovered. The work in this thesis has identified a number of highly active prime structures, from which further investigations are essential in providing more in vitro & in vivo data and the need to prepare more analogues

    Effect of information reduction on certain aspects of operator\u27s performance in a decision task.

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    Dept. of Industrial and Manufacturing Systems Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1975 .S428. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.Sc.)--University of Windsor (Canada), 1975

    The synthesis and evaluation of small organic molecules as cholecystokinin antagonists

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    Cholecystokinin (CCK) is a peptide hormone, present in the alimentary and the CNS. It is the most abundant peptide in the brain. CCK has been implicated in a number of disorders. The link between CCK and anxiety was the basis for this research. A comprehensive discussion on the many types of CCK receptor antagonists is included. For the drug discovery process, a number of synthetic approaches have been investigated and alternative chemical approaches developed. 1,4-Benzodiazepine analogues were prepared, with substitutents In the 1,2 & 3- position of the benzodiazepine scaffold varied, and substituted 3-anilino benzodiazepines exhibited the greatest in vitro activity towards the CCKA receptor subtype. Through extensive screening, pyrazolinone-ureido derivatives were identified, optimised, SAR studied and re-screened. A comprehensive in vivo study on the most active analogue is included, which has a number of common structural features with L-36S, 260 including activity. Pyrazolinone-amide derivatives, bearing the tryptophan moiety were equally active. A number of existing and novel furan- 2(SH)-one building blocks were prepared, from which a selected mini-library of 4- amino-substituted furan-2(SH)-ones were prepared and evaluated. All synthesised compounds were evaluated in a CCK radiolabelled binding assay (CCKA & CCKB), with compounds demonstrating receptor selectivity and lead structures being discovered. The work in this thesis has identified a number of highly active prime structures, from which further investigations are essential in providing more in vitro & in vivo data and the need to prepare more analogues

    Power quality analysis using relay recorded data

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    Demand for electrical power is increasing everyday. Along with the increase in power demand, the characteristics of the loads are also changing. From being high power consuming, simple, robust loads, today loads are more efficient, but at the same time more sensitive. The performance and life of these highly sensitive loads depend a lot on the quality of power supplied to them. Power quality is any deviation of the voltage or current waveform from its normal sinusoidal waveshape. These disturbances include, but are not limited to, sag, undervoltage, interruption, swell, overvoltage, transients, harmonics, voltage flicker and any other distortions to the sinusoidal waveform. Occurrence of one or more of such disturbances is called a power quality event. Automatic classification of these disturbances is important for quick determination of the causes and to characterize possible impacts of the disturbances.Modern microprocessor based protective relays have numerous integrated functions that allow them to provide information on power quality events. It is proposed to utilize the existing numerical relays to analyze the quality of power at any point in the power system. The numerical relays can be programmed to capture the oscillographic waveform or any disturbance on the analogue signal or change of state of the digital signals and store it in the form of Common Format For Transient Data Exchange (COMTRADE) format. These records are then transferred to a central monitoring workstation for off-line analysis. This thesis describes a technique to automate the classification and analysis of the power quality events using relay recorded data. The technique uses voltage duration and magnitude (as specified in the IEEE Std. 1159 - 1995, IEEE Recommended Practice for Monitoring Electric Power Quality) of three phases to detect and classify the events. The classified results are then presented in a user-friendly graphical form. Fast Fourier Transform (FFT) is used to estimate the fundamental frequency and harmonic components in power systems. The graphical user interface of the power quality analysis tool is developed using Microsoft Visual C++ IDE and the algorithms are programmed in C++. The proposed technique was tested using data obtained by simulating different power system disturbances as well as on the data recorded by relays. The algorithms were able to classify the power quality events accurately. In the future, this facility will: enhance the real time monitoring of power quality and provide statistical analysis of available power quality data. From the utility viewpoint, it would allow them to monitor power quality in a cost effective manner and assist in preventive and predictive maintenance besides helping them to fix differential tariff based on the quality of the delivered power. It may also turn out to be a smart tool for them to penalize the consumer polluting the power quality

    An iodine-potassium t-butoxide catalysed conversion of thioamides and thioureas to their oxygen analogs

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    The title conversion, significant for its role in procuring modified nucleic acids has been reported with bis(p-methoxyphenyl) telluroxide, trimethyloxoniujn fluoborate, DMSO/acids and DMSO/iodine. During the course of investigation of the reactions of heterocycles possessing thiourea and thioamide functionals, with iodocarbene generated from iodoform and potassium t-butoxide, we noticed the conversions of these substrates to their oxygen analogs. Here, we report that the title conversion can be performed in a synthetically useful manner, under basic conditions, with the help of iodine/potassium t-butoxide in t-butanol solution

    A facile synthesis of ethyl α-cyano-β-amincacrylates and related compounds

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    Ethyl-α-cyano-β-aminoacrylates (I) have been used as intermediates in the synthesis of pyrimidine derivatives and I(R=H,CH3, C6H5) have been obtained by the condensations of ethyl cyanoacetate with amidines and iminoethers, in relatively poor yields. We now report that both biprotic and monoprotic carbothioamides-thioformamide, thiobenzamides, phenylthioacetamide, quinazolin-4(3H)-thione and pyrrolidin-2(1H)-thione condense with ethyl bromocyanoacetate, with extrusion of sulphur, to form ethyl α-cyano-β-aminoacrylate (I, R=H), ethyl α-cyano-β-aminocinnamates (I, R=-C6H5,-C6H4-OCH3, -C6H4-NO2,P), ethyl α-cyano-β-amino-β-benzylacrylate (I, R= -CH2C6H5), ethyl-α-cyano Δ4(3H), quinazolineace tate (II) and ethyl α-cyano-Δ2,α, pyrrolidineacetate (III) (Table) respectively
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