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- Title
- FABRICATION OF POLYMER OF CLAY NANOCOMPOSITES AND DEVELOPMENT OF CLAY DIGESTION METHODS
- Creator
- Jin, Zhen
- Date
- 2014, 2014-07
- Description
-
This thesis reports on our preliminary development of methods used to assess the risks that polymer/clay nanocomposite (PCN) food packaging...
Show moreThis thesis reports on our preliminary development of methods used to assess the risks that polymer/clay nanocomposite (PCN) food packaging pose to consumers. PCN with 1% - 7% (w/w) montmorillonite (MMT) clay and 3 mass equivalents of maleic anhydride-grafted polyethylene (MAPE) as a compatibilizer dispersed in low-density polyethylene (LDPE) was successfully extruded into thin, free-standing films using a pilot-scaled microcompounder with 65 mm film device. These films had good optical clarity and a reasonably consistent thickness of 35 ± 3 μm. An oxygen permeability analyzer was used to measure oxygen transmission rate and permeability of these fabricated films to demonstrate that they perform similarly to PCN barrier materials intended for commercial applications; these results showed that the films with the highest amount of added clay had better barrier properties than the neat LDPE films. In preparation of experiments to assess whether clay particles can be released from these materials during intended conditions of use, we also explored effective digestion and trace-metal analysis (Inductively Coupled Plasma-Optical Emission Spectroscopy) methods of both pure clay and MMT/MAPE/LDPE films. This work resulted in an effective digestion protocol to fully digest neat clays and PCN films, as well as an analysis method that provides for a 5-orders-of-magnitude linear detection range and single-digit parts-per-billion detection limits for aluminum and magnesium. Silicon was a more challenging element and efforts to eliminate environmental contamination of samples with this element were unsuccessful. While the work presented in this thesis is largely preliminary and numerous questions remain unanswered, the PCN fabrication and ix characterization methods developed here will be invaluable in our future efforts to understand the risks that nanocomposite food packaging materials pose to human health.
M.S. in Food Process Engineering, July 2014
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- Title
- TRANSMISSION RESERVE DESIGN IN ELECTRICITY MARKETS CONSIDERING RAMPING CONSTRAINTS AND LOAD UNCERTAINTY
- Creator
- Xiao, Xuli
- Date
- 2016, 2016-12
- Description
-
With increasing penetration of renewable energy, uncertainty challenges ISOs to keep power balance in real-time. As ramping issues draw public...
Show moreWith increasing penetration of renewable energy, uncertainty challenges ISOs to keep power balance in real-time. As ramping issues draw public attention, many ISOs have instituted flexible ramping products to ensure ramping reserve at generation side. However, not all the ramping reserves are deliverable when a transmission line is already congested. In the real-time market, if an uncertain load estimation is known at peak time t+10mins previously, SCUC/SCED is able to spare transmission reserve by changing the dispatch at time t with additional uncertain load constraints at t. To spare transmission reserve under uncertainty, this research proposes an uncertain load estimation to generate an estimated uncertain load and uncertainty constraints at t+10 in SCUC/SCED: with the help of a stochastic optimization model, uncertainties are quantified as a random actual load y and utilized in a modified stochastic model for undeliverable ramping reserve issues; once the optimal total system generation x is obtained, treated as an estimated uncertain load, uncertainty constraints are added at t+10mins in SCUC/SCED to obtain a secure dispatch at t. Therefore, transmission ramping reserve is ensured by a change in dispatch at t. Numerical results show that this design enhances the economy and scalability of power systems. In addition, scalability analysis proves it works for any scale of power systems with multiple local peak loads.
M.S. in Electrical Engineering, December 2016
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- Title
- IMPACT OF INOCULUM LEVEL ON THE TRANSFER OF SALMONELLA SEROVARS FROM CONTAMINATED ALMOND BUTTER TO FOOD CONTACT MATERIALS
- Creator
- Zheng, Yue
- Date
- 2012-11-19, 2012-12
- Description
-
Outbreaks of salmonellosis associated with nut butter have raised public concerns of sanitation issues in nut butter processing. The high fat,...
Show moreOutbreaks of salmonellosis associated with nut butter have raised public concerns of sanitation issues in nut butter processing. The high fat, low-moisture characteristics of nut butters significantly affect the efficiency of regular cleaning and sanitizing programs, allowing cross-contamination issues to persist on processing equipment. Besides organic matter in food soil, microbial load could also be a factor affecting efficacy of chemical sanitizers. The FDA Food Code (2005) require a 5-log bacterial reduction in testing the efficacy of a chemical sanitation method. As a result, evaluation of microbial transfer is essential for establishing methods for equipment sanitation. The first study of this thesis (Section 4.1) evaluated the survival of Salmonella serovars in almond butter at 25 ± 2 oC. This was achieved by investigating the survival of Salmonella Tennessee and Salmonella Oranienburg in inoculated almond butter sample for up to two weeks. These Salmonella serovars were inoculated into creamy almond butter separately and stored at 25 ± 2 oC. Results showed that Salmonella populations decreased slowly and could survive in almond butter for at least two weeks. This study also investigated the effect of initial inoculum level, contact time, food-contact material and bacterial serovar on the subsequent potential for transfer of bacteria to equipment surfaces (Section 4.2). Almond butter inoculated with Salmonella Oranienburg and Tennessee at different inoculums levels (~3, 6, 9 log CFU/g) were spread on 16 cm2 coupons made of polyethylene, polyurethane, Delrin and stainless steel. Microbial analysis was conducted after physically removing all visible nut butter with laboratory wipes. Results for S. Oranienburg and Tennessee followed similar trends of microbial transfer with regards to inoculum level and food-contact surface. The amount x of Salmonella transferred to a food-contact surface was dependent on initial inoculation levels. An average of 0.88 ± 0.22, 1.53 ± 0.15, and 4.59 ± 0.06 log CFU S. Tennessee per 16 cm2 were transferred to the four different food-contact surface types for low, medium, and high inoculum level, respectively. An average of 1.25 ± 0.24, 2.08 ± 0.08, and 4.55 ± 0.35 log CFU S. Oranienburg per 16 cm2 were transferred to the same four different foodcontact surfaces for low, medium, and high inoculum levels, respectively. The third part of this study (Section 4.3) determined the transfer of Salmonella from contaminated food-contact coupon surfaces to almond butter. Uninoculated almond butter was applied on the surface of previously contaminated food-contact coupon surfaces. More than 5 log CFU/16 cm2 Salmonella could transfer to clean almond butter after immediate contact (within 5 min) with the contaminated area. These findings help advance our understanding of factors affecting microbial transfer between nut butters and processing equipment surfaces. This research can be used to support future cleaning and sanitation studies for nut butter processing equipment.
M.S. in Food Safety and Technology, December 2012
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- Title
- Structural considerations in the design of modern abattoirs and cold storage warehouses
- Creator
- Edlund, Lawrence L
- Date
- 2009, 1920
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/structuralconsid00edlu
Thesis (B.S.)--Armour Institute of Technology
- Title
- SITUATING FANS' SOCIAL MEDIA PRACTICES IN THE CONTEXT OF FAN STUDIES
- Creator
- Rao, Xi
- Date
- 2015, 2015-05
- Description
-
This paper explores how TV fans use social media. By revtewmg academic perspectives on fandom ofTV shows and social media in past several...
Show moreThis paper explores how TV fans use social media. By revtewmg academic perspectives on fandom ofTV shows and social media in past several decades, this paper discusses the way that audiences react to TV shows using the affordance of social media. At the begirming, this article traces the image, activities, and meaning of fandom. Fans were portrayed as deviant creatures until the late 80s. This image was clarified when people looked into fans and their creative works. Scholars realized that fans productively generated creative products based on the given materials, which reflected the social experience of the creators. Therefore, fandom was soon understood as a way of fans to resist the dominant culture in the society. Later on, social media offer fans an immediate, widespread platform to contribute to the TV conversation. With this platform, normal fans show up. Different from productive fandom, median fans are less active in making new meanings of the TV program. Interestingly, a large number of TV audiences are using social media during the broadcast, participating in the discussion of shows. This evidences the convergence of the traditional media, TV, and the new media, social media. It is also found that comments of TV viewers on social media in turn, influence the content of the TV show. Rather than merely spectators, fans are a part of the TV production. As a special case, gender is discussed from the perspective of fandom. Female composers dominant the fan-writing world. Study the producers and products of fan fiction may provide valuable insights into gender dilemmas in the real world. At the end of this essay, 1 summarize how social media atTect the participation of TV fans and discuss remaining questions worthy of future research. Since fandom becomes ubiquitous in the social media age, it is possible to explore fandom as a way to better understand our daily life.
M.S. in Information Architecture, May 2015
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- Title
- Mycoflora of Indoor Dust and Alternaria Alternata Growth on Building Materials
- Creator
- Simpson, Stacy
- Date
- 2011-10-27, 2011-12
- Description
-
Alternaria alternata, a clinically significant mold species is associated with allergic disease and asthma. An indoor growth of A. alternata...
Show moreAlternaria alternata, a clinically significant mold species is associated with allergic disease and asthma. An indoor growth of A. alternata may initiate atopic symptoms, accumulate in dusts, and discolor and deteriorate indoor building materials. Environmental control should be the initial approach to maintain a healthy indoor environment and manage allergic diseases. The current thesis investigated indoor dusts from various environments for mold spores and Alt a 1. Laboratory studies were carried out to determine if or which commercially available mold-resistant treatments and building materials could efficiently decrease A. alternata growth and Alt a 1. The mycoflora of indoor dusts was microscopically examined and the clinically significant allergen from A. alternata, Alt a 1 was measured in sampled dusts using a monoclonal anti-recombinant Alt a 1 (rAlt a 1) enzyme linked immuno-sorbent assay (ELISA). To investigate building material susceptibility untreated, mildew-resistant painted, and commercially available biocide treated building materials were inoculated with A. alternata spores, incubated in a humidity controlled chamber, and compared for mold growth and the presence of Alt a 1. A photo-monitoring technique was used to survey and determine mold growth surface area coverage. Alt a 1 immuno-reactivity of superficial mold growths was analyzed with the ELISA. The microscopic speciation of mold spores indicated that a diverse mycoflora can be found in indoor dusts. Although A. alternata was found in low concentrations in a few samples, Alt a 1was below the limit of detection. Nevertheless, mold spores can significantly contribute to the complexity of indoor dusts. A. alternata grew on all tested building materials but both painted and treated building materials inhibited mold growth in comparison to untreated samples. Not all material surfaces contained detectable levels of Alt a 1. Comparisons between untreated and painted building material groups indicated that a significant difference between the Alt a 1 accumulation content could not be established. To establish a standard sampling protocol and reliable prevention methods for mold contamination and exposure more knowledge about indoor molds must be gained.
M.S. in Environmental Engineering, December 2011
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- Title
- WEB-BASED CONTEMPORANEOUS DELAY ANALYSIS
- Creator
- Pektas, Murat
- Date
- 2011-11-22, 2011-12
- Description
-
The construction industry is fragmented due to the many stakeholders and the diverse phases involved in a construction project. On time,...
Show moreThe construction industry is fragmented due to the many stakeholders and the diverse phases involved in a construction project. On time, within budget, with required quality are essentials of a successful project. However, most construction projects are faced with delays, which obstruct success. To recover the damage caused by delays, both the delays and the parties responsible for them should be identified accurately. Daily window delay analysis outperforms other delay analysis methods, but it requires intensive day-by-day information. The information flow among the project stakeholders must be smooth and speedy at all stages of the production process not only to achieve the basic project objectives but also to let project stakeholders recognize the delays and the parties responsible for them in order to recover time and cost. The Internet is attractive for transferring information promptly and economically with no regional or temporal borders. To merge the power of the Internet and to ease time consuming delay analysis, a web-based application is proposed to analyze delays effectively and contemporaneously, to reduce time and cost, and to provide historical data. The application considers the day-by-day variation in critical path(s) during the project life cycle. The application gives accurate and repeatable results for apportioning project delays, accelerations and decelerations among involved parties. The manual effort required by traditional systems is minimized with the application’s simple, easy to use, yet effective and highly automated features. Moreover, the database structure of the application is designed to store and manage more than one project at a time to let its users calculate the overall performance of the company including all projects, and to calculate average durations for activities that can come up in future projects.
M.S. in Civil Engineering, December 2011
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- Title
- A METHODOLOGY FOR MAJOR BUS ROUTE RESCHEDULING TO IMPROVE TRANSIT PERFORMANCE
- Creator
- Lu, Xi
- Date
- 2012-08-01, 2012-07
- Description
-
In a period of growing transit operating deficits, increasing attention and concern is being directed at both the decreasing levels of...
Show moreIn a period of growing transit operating deficits, increasing attention and concern is being directed at both the decreasing levels of productivity of transit systems in general and the broad differences in measured service performance compiled for various transit systems. The purpose of this study is an assist public transit managers by providing them with a mathematical technique to analyze the efficiency with which serviced is produced and the effectiveness with which it is consumed. By providing the analysis model which not requires an extensive amount of data, the operator can have tool for decision-making of profit and market growth. Thus, transit managers will be able to access the performance of the agency and areas where improvements can be realistically achieved. Using the urban operation of the Chicago Transit Authority, a transit performance model is developed to analysis efficiency and effectiveness of the city's bus system. As the system exists, there are 144 bus routes start and end, frequency of dispatching buses and ridership changes from Weekdays and Weekend, peak hour and off-peak hour. In many of these routes, vehicles are used inefficiently and ineffectively, only a few passengers carried in some routes in off-peak hour, yet in other routes through the Central Business District (CBD) area, there are always not enough buses in peak hour. Also, some routes cannot provide enough on-time arrival service and some special group like elderly and handicapped cannot receive enough service in certain area. The goal of case research is to determine to understand the transit performance of Chicago Transit Authority and to select the optimal improvement projects to maximize the performance in term of economy and social equity.
M.S. in Civil Engineering, July 2012
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- Title
- SUSTAINABLE NEW CITY MENTOUGOU, CHINA
- Creator
- Yin, Lu
- Date
- 2013-04-30, 2013-05
- Description
-
This thesis will demonstrate one of the first urban models for the future of China’s growth. The Urban Operating System and GPS make the smart...
Show moreThis thesis will demonstrate one of the first urban models for the future of China’s growth. The Urban Operating System and GPS make the smart city smarter by linking up networks of billions of distributed sensors, systems, and intelligence across urban environments via city-scale operating systems. Personal Rapid Transit system runs everywhere and it is accessed and ordered by smart phone. Green belt is the medium that links all the natural area and parks in the city which become the core element in the city because it plays the most important role. Two types of transportation system including the Meglev for 10 minute access to Beijing and the PRT system for all internal urban mobility. The population of the new city is 80000. 80% of the people live here and work here, 20% of the people live here but work in Beijing. 30% of the people will use PRT system everyday. All the city blocks are mixed-use blocks. There are several types of residential buildings including mid-rise, high-rise and Beijing traditional courtyard house. This sustainable new city provides quality of lift to all the people live in the city.
M.S. in Architecture, May 2013
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- Title
- DAMAGE DETECTION OF STRUCTURES USING INTERVAL FINITE ELEMENT METHOD
- Creator
- Venkitaraman, Shyamala
- Date
- 2012-04-16, 2012-05
- Description
-
Health assessment and damage detection for existing structures is an essential procedure for their safe and reliable operation so that any...
Show moreHealth assessment and damage detection for existing structures is an essential procedure for their safe and reliable operation so that any catastrophic failure may be prevented in a timely manner. However, results obtained from a health assessment of a structure possess uncertainties in measurements, system properties and loads. Furthermore, the conventional deterministic structural analyses are incapable of considering these uncertainties, thereby resulting in error when estimating the state of health of a structure. Interval (unknown-but-bounded) representation is one method to quantify uncertainty in a physical system. Using an interval variable, the uncertain parameter is bounded between extreme values. In this work, a new method for damage assessment of structures is developed that utilizes the results from structural health assessment as uncertain input parameters in an interval finite element analysis scheme. This method, due to its capability of considering uncertainties, offers a more robust process for estimating the possible existence of damage and overall health of the structure. As an illustrative example, the method is applied for a failed sign support structure. First, the structure's response from previous health assessment procedure was used to construct uncertain interval responses. Then using these interval responses as input parameters, an interval finite element method was performed. The results of the analysis verify and correlate with the failure location of the actual structure. Moreover, the lifetime assessment of the structure obtained from this method is the lower bound of, and correlates with the actual failure time of the structure.
M.S. in Civil Engineering, May 2012
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- Title
- PARADIGM SHIFT IN REMOTE EDUCATION FOR THE LABORATORY: A SOCIAL APPROACH TO DISTANCE LEARNING
- Creator
- Hanley, Richard
- Date
- 2011-12, 2011-12
- Description
-
With modern telecommunication tools the ability for two individuals to work together remotely has greatly improved. Moreover, there have been...
Show moreWith modern telecommunication tools the ability for two individuals to work together remotely has greatly improved. Moreover, there have been great strides made to improve handling medium to large groups of people in real time in remote settings, viz. the teleconference and webinar. However, the status of remote tools for laboratory environments where there is significant hardware and the individuals are more likely to talk amongst themselves in irregular patterns is not nearly as well studied. This thesis examines the way most laboratories in electrical engineering are setup, and creates a model for how to create a remote environment for distance learning. It then discusses the current state of the art, and how such an implementation of the model can be made with such tools. Finally a usability study of the implementation is examined. The primary result of the usability study is that when moving to a remote environment the social paradigm that students and instructors use is likely to change, and simply working on creating a virtual mirror to the laboratory may not work in the future.
M.S. in Electrical Engineering, December 2011
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- Title
- SURVIVAL AND GROWTH OF LISTERIA MONOCYTOGENES IN CHOPPED GREEN AND RED BELL PEPPERS USING PREDICTIVE MODELING
- Creator
- Zhang, L1jie
- Date
- 2015, 2015-07
- Description
-
Listeria monocytogenes (L. monocytogenes) is a Gram-positive pathogenic organism and the causative agent of human and animal listeriosis....
Show moreListeria monocytogenes (L. monocytogenes) is a Gram-positive pathogenic organism and the causative agent of human and animal listeriosis. Listeriosis is a gastrointestinal or invasive systemic illness resulting from consumption of contaminated food products, mainly cheese, deli meats, and fresh produce, by L. monocytogenes. In recent years, several foodborne outbreaks have been reported that were associated with fresh produce, such as cantaloupe, celery and sprouts. Temperature is considered a major factor that affects L. monocytogenes growth during storage. The proliferation of L. monocytogenes varies on different produce items based on storage temperature. In this study, the persistence and population dynamics of three L. monocytogenes strains, LS806 (cheese isolate), LS810 (cantaloupe isolate) and LS808 (celery isolate) were evaluated by incubating inoculated fresh-cut green bell pepper and red bell pepper at various temperatures (5oC, 10oC, and 25oC) for 14 days. To assess the risk of L. monocytogenes in these fresh-cut vegetable items, a primary predictive model was fitted for L. monocytogenes growth data using DMFit. Green bell pepper had significantly (P<0.05) higher pH and aw, and higher amounts of yeast and mold and Enterobacteriaceae than did red bell pepper. In green bell pepper, all three strains showed no significant difference (P>0.05) in growth rate when incubated at the same temperature. In red bell peppers, LS808 had the highest (P<0.05) growth rate at both 5°C and 25°C out of the three strains. All of the three strains grew significantly faster (P<0.01) at 25°C than either 5°C or 10°C in both green and red bell peppers. All three strains obtained less than 1 log10 growth increase after incubating at 25°C for 6 hours on pre-chilled produce. Some strains (LS806 and LS810) significantly increased (P<0.01) during two 5-hour 25°C incubations, but did not reach 1 log10 growth increase. The results indicate that L. monocytogenes not only persists, but also grows in chopped green and red bell peppers at 5, 10, and 25°C, and strains grew faster at the higher temperature (25°C). Data obtained could be further evaluated for determining whether Time/temperature control for safety (TCS) designation should be applied to chopped green and red bell peppers.
M.S. in Food Safety and Technology, July 2015
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- Title
- STRUCTURAL CHARACTERIZATION OF THE FLIGHT MUSCLE OF MANDUCA SEXTA
- Creator
- Cheng, Yu-shu
- Date
- 2013-04-22, 2013-05
- Description
-
There are several properties of the flight muscle Manduca sexta that are interesting. In its physiological characteristics, like mammalian...
Show moreThere are several properties of the flight muscle Manduca sexta that are interesting. In its physiological characteristics, like mammalian skeletal and cardiac striated muscle, it is a synchronous muscle. However, it is much more similar structurally to the more widely known asynchronous insect flight muscles of Drosophila and Lethocerus. The goal of the thesis is to study the structural characteristics and perform mechanical studies of dorsal and ventral muscle of Manduca flight muscle. In pursuit of this goal, a secondary purpose was to develop better storage conditions for skinned insect muscle which can maintain muscle structure and function. Maximum active force as a function of time in storage was compared for storing at 4℃ without glycerol and storing at -80℃ with 75% glycerol. The maximum force values were almost the same during days 0-4. However, the muscle stored at -80℃ with 75% glycerol gave higher active force in high calcium (pCa 4.5) solution over a longer time in storage than muscle stored at 4℃. Both ventral and dorsal muscles can deliver 40-50% of original active force for up to 21 days in storage. X-ray diffraction experiments were done to compare the response of chemically skinned Manduca flight muscle to temperature and to the induction of rigor. The lattice spacing (d10) decreased and intensity ratio I20/I10 increased when the temperature of the relaxing solution bathing the solution increased from 10℃ to 40℃. Lattice spacing (d10) decreased, but the I20/I10 intensity ratio increased slightly while concentration of dextran increased from 1% to 6%. Six percent dextran was insufficient to restore the in vivo lattice spacing.
M.S. in Molecular Biochemistry and Biophysics, May 2013
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- Title
- DETERMINATION OF REDUNDANCY IN STRUCTURES USING INTERVAL UNCERTAINTY ANALYSIS
- Creator
- Amirshaghaghi, Sayeh
- Date
- 2014, 2014-05
- Description
-
Existence of redundancy in structures plays an important role in increasing their safety and reliability. However, using state-of-the-art...
Show moreExistence of redundancy in structures plays an important role in increasing their safety and reliability. However, using state-of-the-art deterministic and probabilistic approaches, all possibilities for estimation of redundancy (e.g. due to occurrence of different damage scenarios) have not been considered. One of the methods to quantify the presence of uncertainties in a system is to use interval variables. In this work, a new method for estimating the redundancy using interval structural analysis is developed. This method, hereafter referred to as Interval Redundancy Analysis (IRA), is robust and considers possibilities of strength reduction for each element leading to failure. Independent intervals for reduction of the strength for five damage scenarios of intact, slightly damage, moderately damaged, severely damaged, and completely damaged as well as strength of each element are considered. A numerical example to show the behavior of the developed method with comparison to Monte-Carlo simulation results is presented.
M.S. in Civil Engineering, May 2014
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- Title
- Tests on a four-cycle automobile engine
- Creator
- Barrett, D. O., Morgan, C. W.
- Date
- 2009, 1908
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/testsonfourcycle00barr
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaves 1-3
- Title
- THE RELATIONS OF LEADER EMPOWERING BEHAVIORS ON EMPLOYEE PERFORMANCE: MODERATED BY GENDER DYAD COMPOSITION
- Creator
- Zigun, David J
- Date
- 2016, 2016-07
- Description
-
This study examined the possible moderating effect of gender dyadic composition on the relationship between Leadership Empowering Behaviors ...
Show moreThis study examined the possible moderating effect of gender dyadic composition on the relationship between Leadership Empowering Behaviors (LEBs) and employee performance across 221 supervisor-subordinate dyads in a Fortune 500 Midwestern U.S. company. The relationships between LEBs and employee performance moderated by gender dyadic composition were examined, as well as possible group differences of LEB ratings between gender dyad group membership. The goal of this study was to test the moderating role of gender dyadic composition on the relationship between LEBs and employee performance. This study obtained both supervisor ratings of employee performance and employee ratings of LEBs, allowing for the use of multi-source data. Results supported the expected relationship between LEBs and employee performance but neither indications of a moderating effect by gender dyads were found, nor were there group differences in perceptions of LEBs. This study adds to the existing literature because previous research has predominantly focused on examining employee perceptions of LEBs and related outcomes, but this was the first study to explore the potential moderating effect of gender dyads in this relationship. Implications of this study are explored.
M.S. in Psychology, July 2016
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- Title
- DEVELOPMENT OF A TESTBED FOR STUDYING SECURITY ISSUES IN VOIP NETWORKS
- Creator
- Olawoye, Oladeji
- Date
- 2011-12-06, 2011-12
- Description
-
VoIP is increasingly becoming an alternative to the traditional PSTN for Telephony this is as a result of certain advantages and services...
Show moreVoIP is increasingly becoming an alternative to the traditional PSTN for Telephony this is as a result of certain advantages and services offered by VoIP. VoIP will be considered able to fully replace PSTN if it can provide same or better Quality of Service and Security guaranty as PSTN. Delivering telephony services over (best-effort and connectionless) IP data network faces two main issues not experienced in PSTN, security and quality of service; security in the sense that telephone calls will be susceptible to attacks that are known in the Internet, quality of service in the sense that voice packets now have to compete with packets of other traffic for a limited bandwidth. Researches are ongoing in these two fields to make experience on VoIP similar to the traditional telephone. The focus of this thesis work is in the security aspect. SIP protocol has become one of the most popular signaling protocols used for VoIP, SIP architecture is an open architecture originally developed for trusted communications among trusted partners, and therefore much thought was not given to security. Adopting SIP as a main protocol used in VoIP in the Internet where there are where there are lots of hostile users calls for more ways to properly secure its use. The thesis work involves setting up of a SIP based VoIP network based on open source SIP telephony platforms to study various security issues in a SIP-Based VoIP network and experiment some proposed detection mechanism. The contribution of this work is to develop a graphical user interface in the UNIX environment using Java that makes the execution of the attack scenarios easy to carry out and observe.
M.S. in Electrical Engineering, December 2011
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- Title
- Study of ideal dry pipe valve
- Creator
- Hepp, A. A., Smith, E. J. L.
- Date
- 2009, 1906
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/studyofidealdryp00hepp
Thesis (B.S.)--Armour Institute of Technology
- Title
- COMPRESSIVE SENSING AND RECONSTRUCTION : THEORY AND APPLICATIONS
- Creator
- Krishnamurthy, Ritvik Nadig
- Date
- 2014, 2014-07
- Description
-
Conventional approach in acquisition and reconstruction of images from frequency domain strictly follow the Nyquist sampling theorem. The...
Show moreConventional approach in acquisition and reconstruction of images from frequency domain strictly follow the Nyquist sampling theorem. The principle states that the sampling frequency required for complete reconstruction of a signal is at least twice the maximum frequency of the original signal. This dissertation studies an emerging theory called Compressive Sensing or Compressive Sampling which goes against the conventional wisdom. Theoretically, it is possible to reconstruct images or signals accurately from a number of samples which is far smaller than the Nyquist samples. Compressive Sensing has proven to have farther implications than merely reducing sampling frequency of the signal. Possibility of new data acquisition methods from analog domain to digital form using fewer sensors, image acquisition using much smaller sensors array, to name a few. This novel theory combines sampling and compression methods thereby reducing the data acquisition resources, such as number of sensors, storage memory for collected samples and maximum operating frequency. This dissertation presents some insights into reconstruction of grey scale images and audio signals using OMP and CoSaMP algorithms. It also delves into some of the key mathematical insights underlying this new theory and explains some of the interactions between Compressive Sensing and related elds such as statistics, coding theory and theoretical computer science. viii
M.S. in Computer Engineering, July 2014
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- Title
- PSYCHOLOGICAL WELL-BEING AND ONLINE MINDFULNESS TRAINING
- Creator
- Stickney, Laurie
- Date
- 2013-04-15, 2013-05
- Description
-
Despite the improvements in resources and communication in today’s world, many people still do not have access to mental health resources....
Show moreDespite the improvements in resources and communication in today’s world, many people still do not have access to mental health resources. Mindfulness, a type of meditation, has been shown to be effective at reducing stress, reducing pain, and increasing general mental well-being. Mindfulness has the potential to reach many people though internet-based interventions. However, more research is needed to determine whether mindfulness retains its efficacy when delivered over the internet. Participants engaged in a six week program of internet-based mindfulness interventions. Facets of mental well-being were assessed at various time points including mood state, anxiety, quality of life, mindfulness, and psychological inflexibility. Hierarchical Linear Modeling demonstrated that over time, participants significantly increased their level of mindfulness and decreased in their psychological inflexibility. Measurements pertaining to mood, anxiety, quality of life, and perceived stress did not change significantly. Nonetheless, results from the present study suggest the potential efficacy of internet-based mindfulness interventions and highlight the need for future research in this domain.
M.S. in Psychology, May 2013
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