Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2007

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 631 - 660 of 3831

Full-Text Articles in Engineering

Femtosecond Laser Microprocessing Of Aluminum Films And Quartz, David Doerr Aug 2007

Femtosecond Laser Microprocessing Of Aluminum Films And Quartz, David Doerr

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Laser micro and nano-machining using sub-picosecond laser pulses has become a very active area of research, driven by the development of more user-friendly lasers. An improved understanding of the advantages and limitations of using these lasers when processing various materials is desirable.

Ablation of 20 nm thick aluminum films was carried out using pulse widths from 300 fs to 6 ns to achieve sub-micron ablation diameters. Resolution and quality of the resulting craters is compared and discussed. The minimum crater diameter obtained with complete ablation of the film was 130–260 nm for a 400 nm wavelength, 400 fs pulse focused …

Go to article

Computer-Based Instruction For Engineering Education In The Developing World, Bradford G. Singley Aug 2007

Computer-Based Instruction For Engineering Education In The Developing World, Bradford G. Singley

Theses and Dissertations

Although civil engineers continually develop new ways to solve problems involving water, energy, infrastructure and environmental sustainability, these innovations can take years – or even decades – to reach developing countries. Computer-based instruction has the potential to dramatically decrease this lag time by improving engineering education in the developing world. This paper discusses the development of instructional simulations, based on the theory of model-centered instruction. These simulations can serve as self-paced learning modules, which can be accessed for free over the Internet. A pilot learning module was developed for the United Nations Educational Scientific and Cultural Organization (UNESCO) on the …

Go to article

Adaptive Quaternion Control For A Miniature Tailsitter Uav, Nathan B. Knoebel Aug 2007

Adaptive Quaternion Control For A Miniature Tailsitter Uav, Nathan B. Knoebel

Theses and Dissertations

The miniature tailsitter is a unique aircraft with inherent advantages over typical unmanned aerial vehicles. With the capabilities of both hover and level flight, these small, portable systems can produce efficient maneuvers for enhanced surveillance and autonomy with little threat to surroundings and the system itself. Such vehicles are accompanied with control challenges due to the two different flight regimes. Problems with the conventional attitude representation arise in estimation and control as the system departs from level flight conditions. Furthermore, changing dynamics and limitations in modeling and sensing give rise to significant attitude control design challenges. Restrictions in computation also …

Go to article

Lateral Resistance Of Piles At The Crest Of Slopes In Sand, Artak Davit Mirzoyan Aug 2007

Lateral Resistance Of Piles At The Crest Of Slopes In Sand, Artak Davit Mirzoyan

Theses and Dissertations

Pile foundations near the crest of a slope are often required to resist lateral loads. This is particularly important for piles at the abutments of bridges. However, limited full-scale test data are available to indicate how the lateral resistance of a pile would be affected when it is located near the crest of a slope. To investigate the effect of a slope on lateral pile resistance, three full scale lateral load tests were conducted on an instrumented steel pipe pile. For the first test, the pile was laterally loaded in horizontal ground. For the second test the pile was at …

Go to article

Oxygen Enrichment Effect Of Mno2-Pt/C Compound Catalyst To The Cathode Of Pemfc, Hong-Feng Xu, Mao-Feng Zhang, Quan-Quan Gan, Cai-Sheng Huang Aug 2007

Oxygen Enrichment Effect Of Mno2-Pt/C Compound Catalyst To The Cathode Of Pemfc, Hong-Feng Xu, Mao-Feng Zhang, Quan-Quan Gan, Cai-Sheng Huang

Journal of Electrochemistry

TO study of the oxygen storage material of air cathode is crucial for increasing performance of proton exchange membrane fuel cell.Using the MnO2 as oxygen storage materials,a MnO2-Pt/C catalysts were prepared and is used to replace the conventional Pt/C in air cathode.The electrochemical performance of air cathode composed of MnO2 supported on Pt/C and the properties of fuel cell composed of MnO2-Pt/C were investigated by using the CV,galvanostatic dischange method and TEM.

Go to article

Growth Mechanism And Morphology Of Electrodeposited Micro-Nanocrystalline Iron, Qiao-Xin Zhang, Jia-Ming Zhang, Li-Ning Yang Aug 2007

Growth Mechanism And Morphology Of Electrodeposited Micro-Nanocrystalline Iron, Qiao-Xin Zhang, Jia-Ming Zhang, Li-Ning Yang

Journal of Electrochemistry

Effects of current density,reaction temperature,electrolyte concentration and surfactant on the electrochemical deposition of micro-nanocrystalline iron were studied.Morphologies and structures of the samples were characterized by SEM and XRD,the results showed that the electrodeposits is slice α-Fe under little current and the density,lower temperature and higher concentration,and the dentritic α-Fe is under opposite conditions,but the influence from surfactant is unconsicously.Moreover,the growth mechanism of the electrodeposits was also analysed here.

Go to article

Studies On Catalytic Mechanism Of Li/Socl2 Batteries By Metal Phthalocyanine Complexes, Zhan-Wei Xu, Qing-Jin Sun, Bi-Yun Su, Tu-Lin Che, Yan-Hong Song, Yao-Min Li, Jian-She Zhao Aug 2007

Studies On Catalytic Mechanism Of Li/Socl2 Batteries By Metal Phthalocyanine Complexes, Zhan-Wei Xu, Qing-Jin Sun, Bi-Yun Su, Tu-Lin Che, Yan-Hong Song, Yao-Min Li, Jian-She Zhao

Journal of Electrochemistry

Effects of metal phthalocyanine comlexes MPc(M= Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ)) as electrochemical catalysts on the performance of Li/SOCl2 batteries have been examined at constant resistance.And the reasons of MPc affecting the discharged voltage and discharged time of Li/SOCl2 batteries were also brought forward.A few new viewpoints on the catalytic mechanism of the reduction of thionyl chloride by phthalocyanine complexes were proposed.

Go to article

Electro-Chemical Oxidation Kinetics Of The V(Iv) In The Sulfuric Acid Solution, Yong-Lian Qiao, Qian Xu, Jie Zhang, Yu-Chun Zhai Aug 2007

Electro-Chemical Oxidation Kinetics Of The V(Iv) In The Sulfuric Acid Solution, Yong-Lian Qiao, Qian Xu, Jie Zhang, Yu-Chun Zhai

Journal of Electrochemistry

The electro-chemical oxidation kinetics for V(IV) in the sulfuric acid solution were investigated by cyclic voltammetry and steady state polarization curves at a graphite,platinum or conducting polymer electrode.Some kinetics parameters for the electrochemical reaction of V(IV) were calculated according to the Tafel curves.The results showed that the exchange current density and reversibility of V(V)/V(IV) redox reaction at the graphite electrode is largest among the three electrodes.There is the broadest extent of water stability and large oxidgen evolution potential when the conducting polymer was used as a working electrode in the solution of VOSO4(0.5 mol/L) and H2SO …

Go to article

Electro-Generated Mno2 In Supersonic Wave Bath And Its Application In Preparation Of Glyceraldehyde, Yan-Hong Cai, Li-Qun Chen, Ri-Yao Chen, Xi Zheng, Xiao Chen, Zhen Chen Aug 2007

Electro-Generated Mno2 In Supersonic Wave Bath And Its Application In Preparation Of Glyceraldehyde, Yan-Hong Cai, Li-Qun Chen, Ri-Yao Chen, Xi Zheng, Xiao Chen, Zhen Chen

Journal of Electrochemistry

Glyceraldehyde is prepared by using MnO2/ Mn2+as the media in a cationic membrane electrolytic cell.Under ultrasonic high-frequency oscillation,the electro-generated nanometer MnO2 dispersed in the solution with several tens nm till several micron.Then the MnO2 is used for selective oxidation of glycerine to glyceraldehydes.The catalyzing selectivity of MnO2/ Mn2+is high and the current efficiency may account to 97.4 %.

Go to article

Electrocatalytic Separation For Dopamine And Ascorbic Acid Using Poly-Evans Blue Modified Glassy Carbon Electrode And Simultaneous Determination, Li-Qing Lin, Xin-Hua Lin, Hong Yao, Jing-Hua Chen, Guang-Wen Li Aug 2007

Electrocatalytic Separation For Dopamine And Ascorbic Acid Using Poly-Evans Blue Modified Glassy Carbon Electrode And Simultaneous Determination, Li-Qing Lin, Xin-Hua Lin, Hong Yao, Jing-Hua Chen, Guang-Wen Li

Journal of Electrochemistry

Voltammetric behavior of the Dopamine(DA) and ascorbic acid(AA) at Poly-Evans Blue modified electrode were studied and a novel method for determination of the content of DA and AA is established.In pH 4.5 phosphate buffer solution,the modified electrode shows enhanced sensitivity and excellent electrochemical discrimination to DA and AA.The relationship between oxidation peak current and the concentration of DA or AA is linear in the range of 1.0 10-6 ～3.0×10-5mol/L and 5.0×10-6~1.05×10-4 mol/L,the detection limit has been estimated as 2.5(10-7 mol/L and 3.0 ×10-7 mol/ L,respectively.The oxidable potential difference of DA and AA …

Go to article

Prerapation And Supercapacitor Property Of Al Doped Co3O4, Xin Ge, Ye Chen, Chun-Xia Zhang, Chang Shu Aug 2007

Prerapation And Supercapacitor Property Of Al Doped Co3O4, Xin Ge, Ye Chen, Chun-Xia Zhang, Chang Shu

Journal of Electrochemistry

With KOH as precipitator to prepare Aluminum doped Co3O4,X-ray diffraction indicated that the doping Al did not change the crystal structure of Co3O4.Electrochemical properties of the sample were tested by cyclic voltammetry and constant-current charge/discharge.The results showed that the chemical doping improved the specific capacitance.When the mol ratio of Co(Ⅱ) with Al(Ⅲ)was 1∶0.05,the specific capacitance was up to 518.07 F/g within 0～400 mV potenitial at current density 5 mA/cm2.

Go to article

Preparation Of Manganese/Chromium Hexacyanoferrate Modified Glassy Carbon Electrode And Its Electrochemical Behavior, Sheng-Tao Zhang, Xiao-Yan Han, Ming-Yue Xue Aug 2007

Preparation Of Manganese/Chromium Hexacyanoferrate Modified Glassy Carbon Electrode And Its Electrochemical Behavior, Sheng-Tao Zhang, Xiao-Yan Han, Ming-Yue Xue

Journal of Electrochemistry

A film of poly(manganese/chromium hexacyanoferrate)(MnCrHCF)is formed on the glassy carbon electrode(GCE) by Cyclic Voltammetry scanning,and its electrochemical behavior was studied.Factors affecting the electro-deposition of the film such as pH values and sustaining electrolytes,were discussed.And mechanism of the reaction was investigated.

Go to article

Study On The Nano Diamond Stable Water Disperse System And Applying In Composite Chromium Plating, Lai-Xiang Zhang, Hong-Bo Xie, Xue-Kui Ma, Guo-Wu Zhao, En-Cheng Yu, Jia-Zhi Wang Aug 2007

Study On The Nano Diamond Stable Water Disperse System And Applying In Composite Chromium Plating, Lai-Xiang Zhang, Hong-Bo Xie, Xue-Kui Ma, Guo-Wu Zhao, En-Cheng Yu, Jia-Zhi Wang

Journal of Electrochemistry

The nano diamond stable water disperse system was studied.The low-bublles sulfonic anion sufcace active agent had been choosed out for this system.The affect of different physics agitation mothed on the water separate system stablity were conpared.The nano diamond stable water separate system had been applied to the composite chromium electroplating on this tests.The depositing speed,hardnees and wearing capacity of plating layer were tested.And the metallography structure of plating layer was charasterized by SEM.The test results and reaction princeple were discussed.

Go to article

Influence Of Chromium On The Semi-Conductive Property Of Passive Film Formed On Carbon Steel In Bicarbonate/Carbonate Buffer Solution, Jin-Bo Li, Jie-Wu Zhu, Mao-Sheng Zheng Aug 2007

Influence Of Chromium On The Semi-Conductive Property Of Passive Film Formed On Carbon Steel In Bicarbonate/Carbonate Buffer Solution, Jin-Bo Li, Jie-Wu Zhu, Mao-Sheng Zheng

Journal of Electrochemistry

The influence of chromium on the semi-conductive property of the passive film formed at carbon steel in bicarbonate/carbonate buffer solution,is investigated by using electrochemical impedance spectroscopy(EIS).The results showed that the passive film fomed at carbon steel appeared an n-type semi-conductive property,but if the passive film formed at carbon steel with 3% chromium content exhibited an a-p semi-conductive charatcer.The slopes of Mott-Schottky plot of two passive films increased with rising the formation potential,it indicating the defect density of the film decreasing,but for the passive film formed at carbon steel with chromium additive,its donor density was lower about one order of magnitude …

Go to article

Fabrication And Charaterization Of Nitrogen-Doped Tio2 Nanotube Array And Its Visible Light Activity, Hui-Fang Zhuang, Yue-Kun Lai, Jing Li, Lan Sun, Chang-Jian Lin Aug 2007

Fabrication And Charaterization Of Nitrogen-Doped Tio2 Nanotube Array And Its Visible Light Activity, Hui-Fang Zhuang, Yue-Kun Lai, Jing Li, Lan Sun, Chang-Jian Lin

Journal of Electrochemistry

Nitrogen-doped TiO2 nanotube array was fabricated by an electrochemical anodic oxidation followed a wet process.XPS result indicates that the nitrogen atoms were doped into lattice of TiO2 nanotubes.The UV-Vis spectra show that the photoabsorption of N-doped TiO2 nanotube array film is enhanced in the visible light region.Compared with the TiO2 nanotube array film,the N-doped TiO2 nanotubes exhibite a higher photocatalytic activity which is evaluated by the decomposition rate of methyl orange using the tungsten-halogen lamp as light source.

Go to article

Preparation, Structure, And Cv Study Of The Supported Ptruir/Tic Electrocatalysts For Oxygen Electrodes, Sheng Sui, Li-Rong Ma Aug 2007

Preparation, Structure, And Cv Study Of The Supported Ptruir/Tic Electrocatalysts For Oxygen Electrodes, Sheng Sui, Li-Rong Ma

Journal of Electrochemistry

The PtRuIr/TiC electrocatalysts were prepared by method of reduction and deposition on TiC powders as supports together with ultrasonic wave dispersion.The sampls were characterized by BET surface area,scanning electron microscope,X-ray diffraction,and cyclic voltammetry techniques.The active components of Pt,Ru,and Ir particles(2.6%Pt,1.3%Ru,16%Ir,and 80%TiC,by mass) were mainly dispersed on the outer surface of the TiC supports,which structures were in favor of fine variable crystallites.It was found that the electrochemical performance of the PtRuIr/TiC electrodes was about three times as that of the unsupported electrocatalysts with the same active compositions for oxygen evolution reaction.After 120 times of CV cycles,there was almost no PtRuIr/TiC dissolving …

Go to article

Electrocatalytic Oxidation Of Methanol At The Nano Ni-B Amorphous Alloy Powdermicroelectrode, Yi-Xiong Zheng, Shi-Bing Yao, Shao-Min Zhou Aug 2007

Electrocatalytic Oxidation Of Methanol At The Nano Ni-B Amorphous Alloy Powdermicroelectrode, Yi-Xiong Zheng, Shi-Bing Yao, Shao-Min Zhou

Journal of Electrochemistry

Electrocatalytic oxidation of methanol at the nano Ni-B amorphous alloy powder-microelectrode in alkaline media was studied by using cyclic voltammetry.Compared to the highly preferred orientation(220) nickel electrode,The onset potential of methanol electrooxidation at the nano Ni-B microelectrode is negatively shifted about 0.04V,and the current density is increased approximately by 2 orders of magnitude.Thus,the nano Ni-B microelectrode has very strong electrocatalytic activity for the oxidation of methanol.The kinetic parameters were determined with the steady polarization curves.The results show that the rate constants for both the oxidation of Ni(Ⅱ) to Ni(Ⅲ) and the reduction of Ni(Ⅲ) to Ni(Ⅱ) at the nano Ni-B …

Go to article

Pdms Regularly Superhydrophobic Surfaces Prepared By Icp Etching Silicon Model, Run-Xiang Zhang, Yu-Long Zhang, Hua-Shui Lin Aug 2007

Pdms Regularly Superhydrophobic Surfaces Prepared By Icp Etching Silicon Model, Run-Xiang Zhang, Yu-Long Zhang, Hua-Shui Lin

Journal of Electrochemistry

A series of different dimensions regularly micropillar array hydrophobic Poly(dimethylsiloxane)(PDMS) surfaces were obtained by peeling off PDMS which was poured onto the silicon models.The silicon models were prepared by ICP etching technology.The results indicate that the water contact angle(WCA) was increased with the size and the height of the mocropillar,decreased with increasing the distance of the mocropillar when the height of the micropillar was relative small;if the height of the micropillar was relative big,WCA was decreased with increasing the size of micropillar,meanwhile,the distance of the micropillar was a complex factor to WCA,and the height of the micropillar have little influence.The …

Go to article

Ceas E-News 08.28.2007, College Of Engineering And Applied Sciences Aug 2007

Ceas E-News 08.28.2007, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

CEAS project honored as top 2007 Michigan innovations

Go to article

The Syntheses And Electrochemical Performance Of Nano-Mno2 For Supercapacitor, Jun Ma, Ming-Sen Zheng, Quan-Feng Dong Aug 2007

The Syntheses And Electrochemical Performance Of Nano-Mno2 For Supercapacitor, Jun Ma, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Nano-manganese dioxide were prepared by two different methods which are low temperature solid reaction and chemical deposition.The products were characterized by XRD,SEM,BET and constant current charge-discharge tests.The result shows that there is a close relationship between specific capacitance and BET surface areas.Meanwhile the specific capacitance was impacted little by the structure of the nano-manganese dioxides.However,the product performance of high rates,was influenced by structure,the higher rate can be obtained with the more perfect crystal structure.

Go to article

Morphology Of The Pb-Sn Alloy Thin-Layer Electrodeposition, Yan-Jun Du, Zhi-Gang Yin, Tong-Chi Xia Aug 2007

Morphology Of The Pb-Sn Alloy Thin-Layer Electrodeposition, Yan-Jun Du, Zhi-Gang Yin, Tong-Chi Xia

Journal of Electrochemistry

The morphology of Pb-Sn alloy thin-layer electrodeposition was studied.Experimental results showed that the morphology of deposit could vary as the concentration of Pb2+, Sn2+ two kind metallic ion to be changed.The patterns of product appeared the dendritic, ramification, dense branch, fractal, and homogeneous structure and their morphological evolution was caused by the change in anisotropy of crystal growth and different stage of electrodeposits.

Go to article

Effect Of Tension On Corrosion Behavior Of Galvanized Steel Wire For Cable-Stayed Bridge, Xue-Ming Li, Jie-Min Zhou, Qiang Liu, Ling-Feng Kong, Jian-Ting Zhou Aug 2007

Effect Of Tension On Corrosion Behavior Of Galvanized Steel Wire For Cable-Stayed Bridge, Xue-Ming Li, Jie-Min Zhou, Qiang Liu, Ling-Feng Kong, Jian-Ting Zhou

Journal of Electrochemistry

Corrosion of steel wire in cables is a major cause of cable-stayed bridge deterioration. The corrosion behavior of galvanized steel wire at different tension is investigated by polarization voltammetry method and neutral salt spray test in 5% NaCl solution. The physical and chemical properties of corrosion products are characterized by XRD and TG-DTA.The result shows that the corrosion current or corrosion rate of galvanized steel wire is larger with increasing the tension, the white rust of galvanized steel wires at different tension appears within one cycle, the red rust appears after 16 cycles at 15~22kN tension, and 23 cycles at …

Go to article

A Comparison Of Optimized Nonlinear Time History Analysis And The Equivalent Lateral Forces Method For Brace Design, Lukas Balling Aug 2007

A Comparison Of Optimized Nonlinear Time History Analysis And The Equivalent Lateral Forces Method For Brace Design, Lukas Balling

Theses and Dissertations

This thesis presents the development of a design procedure for buckling-restrained braced frames (BRBF's). This procedure uses nonlinear time history analysis and a formal optimization algorithm. The time history analysis includes an elasto-plastic model for the braces. The optimization algorithm is a genetic algorithm. This procedure is referred to throughout the thesis as the "Nonlinear Time History Analysis Procedure with Optimization" (NTHO). Current design specifications for BRBF's are based on inelastic design spectra and approximate formulas for the determination of natural period. These spectra are used to obtain seismic base shear, and the distribution of equivalent lateral forces. Yielding and …

Go to article

Transportation Fuel Research And Development: Statistically Validated Codes And Standards, Fatih Dogan Aug 2007

Transportation Fuel Research And Development: Statistically Validated Codes And Standards, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

The recent establishment of the National University Transportation Center at MST under the "Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users," expands the research and education activities to include alternative transportation fuels and other issues that are at the forefront of society and the national agenda. UMR in partnership with MTI will establish a rural hydrogen transportation test bed for developing, demonstrating, evaluating, and promoting hydrogen-based technologies in a real-world environment. The State of Missouri is ideally suited to develop and demonstrate the proper operation of hydrogen highways in a rural setting, which represents over 25 percent …

Go to article

Achiral And Chiral Analysis Of Polychlorinated Biphenyls (Pcbs) In The Aquatic And Riparian Food Webs In Twelve Mile Creek, South Carolina., Viet Dang Aug 2007

Achiral And Chiral Analysis Of Polychlorinated Biphenyls (Pcbs) In The Aquatic And Riparian Food Webs In Twelve Mile Creek, South Carolina., Viet Dang

All Theses

Polychlorinated biphenyls (PCBs) contamination in the Twelve Mile Creek arm of Lake Hartwell, South Carolina, has been an issue for decades. Lake Hartwell, which is a reservoir located on the border between the states of South Carolina and Georgia, was contaminated with an estimated 440,000 pounds of PCBs. PCBs were released from the Sangamo-Weston capacitor plant located on Town Creek, which feeds into Twelve Mile Creek and ultimately Lake Hartwell. The Twelve Mile Creek tributary connecting the Sangamo-Weston plant to Lake Hartwell has had little attention. Understanding PCBs contamination in the aquatic and riparian food webs of Twelve Mile Creek …

Go to article

Exact Solution Of Time History Response For Dynamic Systems With Coupled Damping Using Complex Mode Superposition, Manoj Kumar Chinnakonda Aug 2007

Exact Solution Of Time History Response For Dynamic Systems With Coupled Damping Using Complex Mode Superposition, Manoj Kumar Chinnakonda

All Theses

An exact solution method for general, non-proportional damping time history response for piece-wise linear loading proposed by Dickens is generalized to piece-wise quadratic loading. Comparisons are made to Trapezoidal and Simpson's quadrature rules for approximating the time integral of the weighted generalized forcing function in the exact solution to the decoupled modal equations arising from state-space modal analysis of linear dynamic systems. The time integral of the forcing function is recognized as a weighted integral with complex exponential and the general update formulas are derived using polynomial interpolation to the forcing function. Closed-form expressions for the weighting parameters in the …

Go to article

Assessment Of Driver Speeds, Compliance In Rural School Zones: Comparison Of Speed By School Level And Time Of Day, Stuart Day Aug 2007

Assessment Of Driver Speeds, Compliance In Rural School Zones: Comparison Of Speed By School Level And Time Of Day, Stuart Day

All Theses

TThis study analyzed driver's speeds prior to entering school zones as well as the speeds traveling through school zones. A comparison was conducted to determine if drivers complied with school speed zones using only the standard school sign arrangement found in the Manual on Uniform Traffic Control Device. Two rural school zones in Oconee County, South Carolina were analyzed in this study as rural areas tend to have higher speeds and fewer other factors that could contribute to changes in driver behavior. In order to gather data, data collection devices known as Hi-Stars were placed in the roadway on both …

Go to article

Enterprise Security Analysis Including Denial Of Service Countermeasures, Chinar Dingankar Aug 2007

Enterprise Security Analysis Including Denial Of Service Countermeasures, Chinar Dingankar

All Theses

Computer networks are the nerve systems of modern enterprises. Unfortunately, these networks are subject to numerous attacks. Safeguarding these systems is challenging. In this thesis we describe current threats to enterprise security, before concentrating on the Distributed denial of Service (DDoS) problem.
DDoS attacks on popular websites like Amazon, Yahoo, CNN, eBay, Buy, and the recent acts of war using DDoS attacks against NATO ally Estonia [1] graphically illustrate the seriousness of these attacks. Denial of Service (DoS) attacks are explicit attempts to block legitimate users' system access by reducing system availability [2]. A DDoS attack deploys multiple attacking entities …

Go to article

Steer It And Clear It: Effectiveness Of Quick Clearance Legislation, Amy Carol Hamlin Aug 2007

Steer It And Clear It: Effectiveness Of Quick Clearance Legislation, Amy Carol Hamlin

All Theses

Innovative incident management strategies have been sought by transportation professionals to minimize the impacts of incidents on traffic operation and safety. Some current quick clearance strategies such as 'Steer It and Clear It' legislation in South Carolina, which requires driver(s) of involved vehicle(s) in a minor incident to move vehicles promptly from the traveled roadway prior to the arrival of the first responders, can potentially reduce the duration of an incident. The research detailed in this paper endeavored to measure the benefit of the Steer It and Clear It law on a section of I-85 in South Carolina. A simulation …

Go to article

Improving The Performance Of Software Defined Radio By Employing Digital Feedback Of Radio Frequency Properties, Joel Simoneau Aug 2007

Improving The Performance Of Software Defined Radio By Employing Digital Feedback Of Radio Frequency Properties, Joel Simoneau

All Dissertations

This dissertation provides tools for the analysis and integration of the hardware and software components of a software defined radio for optimum radio frequency performance. A device is introduced that is able to give baseband feedback of radio frequency properties suitable for analysis in software. Three applications for the device are devised. The first is an image rejection upconverter that achieves greater than 65 dB of image rejection over a broad frequency range without the use of a radio frequency filter. The second application is a baseband correction scheme for extending the bandwidth and improving the magnitude and phase match …

Go to article

First Prev Next Last