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1
Sainani, Varsha. "Hybrid Layered Intrusion Detection System." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_theses/44.
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The increasing number of network security related incidents has made it necessary for the organizations to actively protect their sensitive data with network intrusion detection systems (IDSs). Detecting intrusion in a distributed network from outside network segment as well as from inside is a difficult problem. IDSs are expected to analyze a large volume of data while not placing a significant added load on the monitoring systems and networks. This requires good data mining strategies which take less time and give accurate results. In this study, a novel hybrid layered multiagent-based intrusion detection system is created, particularly with the support of a multi-class supervised classification technique. In agent-based IDS, there is no central control and therefore no central point of failure. Agents can detect and take predefined actions against malicious activities, which can be detected with the help of data mining techniques. The proposed IDS shows superior performance compared to central sniffing IDS techniques, and saves network resources compared to other distributed IDSs with mobile agents that activate too many sniffers causing bottlenecks in the network. This is one of the major motivations to use a distributed model based on a multiagent platform along with a supervised classification technique. Applying multiagent technology to the management of network security is a challenging task since it requires the management on different time instances and has many interactions. To facilitate information exchange between different agents in the proposed hybrid layered multiagent architecture, a low cost and low response time agent communication protocol is developed to tackle the issues typically associated with a distributed multiagent system, such as poor system performance, excessive processing power requirement, and long delays. The bandwidth and response time performance of the proposed end-to-end system is investigated through the simulation of the proposed agent communication protocol on our private LAN testbed called Hierarchical Agent Network for Intrusion Detection Systems (HAN-IDS). The simulation results show that this system is efficient and extensible since it consumes negligible bandwidth with low cost and low response time on the network.
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Guastavino, Rémi. "Elastic and acoustic characterisation of porous layered system." Licentiate thesis, KTH, Aeronautical and Vehicle Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4047.
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For an accurate prediction of the low and medium frequency surface vibration and sound radiation behaviour of porous layered systems, there is a need to improve the means of estimating their elastic and acoustic properties. The underlying reasons for this are many and of varying origin, one prominent being a poor knowledge of the geometric anisotropy of the cell microstructure in the manufactured porous materials. Another one being, the characteristic feature of such materials i.e. that their density, elasticity and dissipative properties are highly dependent upon the manufacturing process techniques and settings used. In the case of free form moulding, the geometry of the cells and the dimensions of the struts are influenced by the rise and injection flow directions and also by the effect of gravity, elongating the cells. In addition the influence of the boundaries of the mould also introduces variations in the properties of the foam block produced. Despite these complications, the need to predict and, in the end, optimise the acoustic performance of these materials, either as isolated components or as part of a multi-layer arrangement, is growing. It is driven by the increasing demands for an acoustic performance in balance with the costs, a focus which serves to increase the need for modelling their behaviour in general and the above mentioned, inherent, anisotropy in particular. The current work is focussing on the experimental part of the characterisation of the material properties which is needed in order to correctly represent the anisotropy in numerical simulation models. A hybrid approach based on a combination of experimental deformation and strain field mapping, and physically based porous material acoustic Finite Element (FE) simulation modelling, is under development which ultimately will provide the anisotropic elastic coefficients and acoustic properties of the porous layered system. The first step, involving new testing methods, is discussed here and demonstrated for a soft foam.
In addition investigations using laser vibrometers combined with finite element modelling of the Panphonics G1 multi-layered panel elements are also discussed. Variations in the mounting conditions, including globally acting restraints, are evaluated through dynamic measurements and acoustic interaction with the surrounding acoustic field. Results from investigations into different changes of the panel design parameters in order to improve the effectiveness in the low frequency range are presented.
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Shousha, Christiane Wahba. "Applying layered queueing modelling to a telecommunication system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ36897.pdf.
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Guastavino, Rémi. "Elastic and acoustic characterisation of porous layered system /." Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4047.
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Tsuji, Yuichi. "Synthesis of π-System-Layered Structures Based on Rigid Scaffolds." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188608.
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Radde, Sven [Verfasser], and Burkhard [Akademischer Betreuer] Freitag. "A Layered Conversational Recommender System / Sven Radde. Betreuer: Burkhard Freitag." Passau : Universitätsbibliothek der Universität Passau, 2013. http://d-nb.info/1037243102/34.
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Calla, Chaitanya. "Two layered ballast system for improved performance of railway track." Thesis, Coventry University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402705.
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Cai, Yi, and 蔡毅. "A virtual prototyping system with reconfigurable manipulators for layered manufacturing." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47046144.
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Zhou, Jianong. "Three-dimensional visualization of multi-layered graphs with application to communications." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27316.
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This thesis introduces two new algorithms for 3D graph drawing and network display. The first algorithm, the Incremental Projection Algorithm , is a new universal algorithm for displaying any graph of any vertex degree. The above algorithm can be implemented to display graph in 3D space without edge crossing. The number of edge bends produced by the algorithm does not excess two. The average time complexity of the Incremental Projection Algorithm is O( N N), where N is the number of vertices in a graph. If there is no degree of vertices great than M, the time complexity of the Incremental Projection Algorithm is O(N). The second algorithm is called Depth-Height Buffer Algorithm. The algorithm is designed for displaying special multi-layered networks. Actually, the algorithm is a method for hidden object elimination. It is useful for multi-layered communication networks visualization. The time complexity of the Depth-Height Buffer Algorithm is O(N log N) . Two demonstration packages of the above algorithms are developed in order, to verify their correctness and functionality.
The thesis also discusses the methods and techniques for 2D graph drawing. In bi-layered crossing reduction aspect the thesis presents a new method called the minimizing angle approach, which may reduce the crossings among the edges with the time complexity of O(|S |max(|N|,|S |)).
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Brockmeier, Oivind. "Automated Loading and Unloading of the Stratasys FDM 1600 Rapid Prototyping System." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31533.
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Rapid prototyping systems have advanced significantly with respect to material capabilities, fabrication speed, and surface quality. However, build jobs are still manually activated one at a time. The result is non-productive machine time whenever an operator is not at hand to make a job changeover. A low-cost auxiliary system, named Continuous Layered Manufacturing (CLM), has been developed to automatically load and unload the FDM 1600 rapid prototyping system (Stratasys, Inc.). The modifications made to the FDM 1600 system are minimal. The door to the FDM 1600 build chamber is removed, and the .SML build files that are used to drive the FDM 1600 are modified at both ends to facilitate synchronized operation between the two systems. The CLM system is capable of running three consecutive build jobs without operator intervention. As long as an operator removes finished build jobs, and adds new build trays before at most every three build jobs, the FDM can operate near indefinitely. The impact of the CLM system on the productivity of the FDM 1600 rapid prototyping system is demonstrated by the expected reduction from the customary eight weeks down to a future three and one-half weeks required to complete the typical forty build jobs during a semester in the course ME 4644 Introduction to Rapid Prototyping at Virginia Tech.Master of Science
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Koch, Douglas J. "Positioning the Reserve Headquarters Support (RHS) system for multi-layered enterprise use." Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Sep/09Sep%5FKoch.pdf.
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Thesis (M.S. in Information Technology Management)--Naval Postgraduate School, September 2009.Thesis Advisor(s): Cook, Glenn. "September 2009." Description based on title screen as viewed on 6 November 2009. Author(s) subject terms: Enterprise architecture, project management, business process transformation, operating model, IT governance, IT systems, data quality, data migration, business operating model, personnel IT systems, HRM, ERP. Includes bibliographical references (p. 89-92). Also available in print.
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Ghosh, Kajari. "Characterizing fracture distribution in layered rocks using geographic information system-based techniques." FIU Digital Commons, 2003. https://digitalcommons.fiu.edu/etd/3932.
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Fractures are discrete planar features that are heterogeneously distributed throughout the earth's upper crust. Methods commonly used to quantify fracture populations typically yield singular values/indexes for the attribute of interest. These values are useful in characterizing the bulk properties of a fracture population, but are unable to address the inherent spatial heterogeneities of the fracture network.
This study explores techniques to map fractures and capture the spatial heterogeneity of fracture networks within a Geographic Information System (GIS). The study was performed on exposures of the intensely fractured Monterey Formation in Santa Barbara, California. Results of the GIS-based spatial analysis provide a framework to (a) quantify the dependence of fracture style on lithology, (b) compare and contrast geometric properties of fracture populations hosted in alternate stratigraphic units, (c) evaluate fracture intensity as a function of proximity to large faults, and (d) quantify geometric properties of fracture networks that impact fluid flow.
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Lazar, Laura. "Fe/Pb layered system a detailed study of the "genuine" superconductor, ferromagnet priximity effect /." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959850090.
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Knight, Thomas. "MARIA : a multi-layered unsupervised machine learning algorithm based on the vertebrate immune system." Thesis, University of Kent, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411943.
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Green, Richard. "Use of a layered knowledge architecture to support multiple views of system development knowledge." Thesis, Keele University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242275.
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Matynowski, Eric D. "Groundwater Modeling and Hydrogeological Parameter Estimation: Potomac Aquifer System, SWIFT Research Center." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/99171.
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The Sustainable Water Interactive for Tomorrow (SWIFT) project in eastern Virginia is a Managed Aquifer Recharge project designed to alleviate the depletion of the Potomac Aquifer System due to unsustainable groundwater withdrawals. At the SWIFT Research Center (SWIFTRC) in Nansemond, VA, a pilot testing well (TW-1) has been implemented to help determine the feasibility of full-scale implementation. The pumping data from TW-1 and observation head data from surrounding monitoring wells (MW) at the SWIFTRC were used to calculate hydrogeological parameters (transmissivity, hydraulic conductivity, specific storage, and storage coefficient). Two sets of data were analyzed from before and after TW-1 was rehabilitated to account for the change in the flow distribution to each screen in TW-1. Comparing the results to past literature, the calculated (Theis and Cooper-Jacob methods) hydraulic conductivity/transmissivity values are within the same order of magnitude. Using borehole logs as well as apparent conductance and resistivity logs, multiple single and multi-layered models for both the upper and middle Potomac aquifers were produced with MODFLOW. Parameter estimation using MODFLOW and PEST and the two sets of observation data resulted in hydrogeological parameters similar to those calculated using Theis and Cooper-Jacob methods. The change in the hydraulic conductivity and specific storage between the pre and post rehabilitation flow distributions is proportional to that change in the flow distribution. For future modeling of the aquifer system, the hydrogeological parameters from the model using the 4/26/19 data set with the post rehabilitation flow distribution is recommended. Drawdown results from a multi-layered MODFLOW model were compared to results using the Theis method using both the Theis-calculated and MODFLOW-PEST modeled hydrogeological parameters. The results were nearly identical except for the Upper Potomac Aquifer (UPA) layer 1, as the model has a large change in aquifer thickness with distance from TW-1 that the Theis-based calculations do not consider. Travel times from the monitoring wells to TW-1 were calculated with the single and multi-layered models pumping 700 GPM from TW-1. Travel times from the SWIFT MW within the UPA sublayers ranged from 204 to 597 days depending on the sublayer, while travel times from the USGS MW within the UPA sublayers ranged from 2,395 to 7,859 days. For the single layer model of the UPA, the travel time from the SWIFT MW to TW-1 was 372 days while the travel time from the USGS MW was 4,839 days. Travel times from the SWIFT MW within the MPA sublayers were 416 and 1,195 days, while travel times from the USGS MW within the MPA sublayers were 4,339 and 11,245 days. For the single layer model of the MPA, the travel time from the SWIFT MW to TW-1 was 743 days while the travel time from the USGS MW was 7,545 days.Master of Science
The Sustainable Water Interactive for Tomorrow (SWIFT) project in eastern Virginia is a project designed to help slow the depletion of the Potomac Aquifer System due to unsustainable groundwater withdrawals. At the SWIFT Research Center (SWIFTRC) in Nansemond, VA, a testing well (TW-1) has been implemented to help determine if the full-scale implementation of the SWIFT project is feasible. The pumping data from TW-1 and observation head data from surrounding monitoring wells (MW) at the SWIFTRC were used to calculate hydrogeological parameters (transmissivity, hydraulic conductivity, specific storage, and storage coefficients). These parameters help describe the behavior of the aquifer system. Two sets of data were analyzed from before and after TW-1 was rehabilitated to account for the change in the flow distribution within TW-1. Comparing the results to past literature, the calculated (using analytical methods, Theis and Cooper-Jacob methods) hydraulic conductivity/transmissivity values are within the same order of magnitude. Using data from the boreholes, multiple single and multi-layered models for both the upper and middle Potomac aquifers were produced with MODFLOW, a groundwater modeling software. Estimating parameters using observation data within MODFLOW resulted in hydrogeological parameters similar to those calculated using the Theis and Cooper-Jacob methods. The change in the hydraulic conductivity and specific storage between the pre and post rehabilitation flow distributions within TW-1 is proportional to that change in the flow distribution. For future modeling of the aquifer system, the hydrogeological parameters from the model using the 4/26/19 (most recent) data set with the post rehabilitation (more current) flow distribution is recommended. Drawdown (decrease in the water table) results from a multi-layered MODFLOW model were compared to results using the Theis method using both the Theis-calculated and MODFLOW modeled hydrogeological parameters. The results were nearly identical except for the Upper Potomac Aquifer (UPA) layer 1, as the model has a large change in aquifer thickness with distance from TW-1 that the Theis-based calculations do not consider. The time it took for a particle of water to travel from the monitoring wells to TW-1 were calculated with the single and multi-layered models pumping 700 GPM from TW-1. Travel times from the SWIFT MW within the UPA sublayers ranged from 204 to 597 days depending on the sublayer, while travel times from the USGS MW within the UPA sublayers ranged from 2,395 to 7,859 days. For the single layer model of the UPA, the travel time from the SWIFT MW to TW-1 was 372 days while the travel time from the USGS MW was 4,839 days. Travel times from the SWIFT MW within the MPA sublayers were 416 and 1,195 days, while travel times from the USGS MW within the MPA sublayers were 4,339 and 11,245 days. For the single layer model of the MPA, the travel time from the SWIFT MW to TW-1 was 743 days while the travel time from the USGS MW was 7,545 days.
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Puerto, Valencia J. (Jose). "Predictive model creation approach using layered subsystems quantified data collection from LTE L2 software system." Master's thesis, University of Oulu, 2019. http://jultika.oulu.fi/Record/nbnfioulu-201907192705.
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Abstract. The road-map to a continuous and efficient complex software system’s improvement process has multiple stages and many interrelated on-going transformations, these being direct responses to its always evolving environment. The system’s scalability on this on-going transformations depends, to a great extent, on the prediction of resources consumption, and systematic emergent properties, thus implying, as the systems grow bigger in size and complexity, its predictability decreases in accuracy. A predictive model is used to address the inherent complexity growth and be able to increase the predictability of a complex system’s performance. The model creation processes are driven by the recollection of quantified data from different layers of the Long-term Evolution (LTE) Data-layer (L2) software system. The creation of such a model is possible due to the multiple system analysis tools Nokia has already implemented, allowing a multiple-layers data gathering flow. The process starts by first, stating the system layers differences, second, the use of a layered benchmark approach for the data collection at different levels, third, the design of a process flow organizing the data transformations from recollection, filtering, pre-processing and visualization, and forth, As a proof of concept, different Performance Measurements (PM) predictive models, trained by the collected pre-processed data, are compared. The thesis contains, in parallel to the model creation processes, the exploration, and comparison of various data visualization techniques that addresses the non-trivial graphical representation of the in-between subsystem’s data relations. Finally, the current results of the model process creation process are presented and discussed. The models were able to explain 54% and 67% of the variance in the two test configurations used in the instantiation of the model creation process proposed in this thesis.
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White, Gregory William. "An investigation of the Australian layered elastic tool for flexible aircraft pavement thickness design." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16663/1/Gregory_William_White_Thesis.pdf.
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APSDS is a layered elastic tool for aircraft pavement thickness determination developed and distributed by Mincad Systems and based on the sister software Circly. As aircraft pavement thickness determination remains an empirical science, mechanistic-empirical design tools such as APSDS require calibration to full scale pavement performance, via the S77-1 curve. APSDS provides the unique advantage over other tools that it models all the aircraft in all their wandering positions, negating the need for designers to use pass to cover ratios and acknowledging that different aircraft have their wheels located at difference distances from the aircraft centerline.
APSDS requires a range of input parameters to be entered, including subgrade modulus, aircraft types, masses and passes and a pavement structure. A pavement thickness is then returned which has 50% design reliability. Greater levels of reliability are obtained by conservative selection of input values. Whilst most input parameters have a linear influence on pavement thickness, subgrade modulus changes have a greater influence at lower values and less influence at higher values. When selecting input values, designers should concentrate their efforts on subgrade modulus and aircraft mass as these have the greatest influence on the required pavement thickness. Presumptive or standard values are generally acceptable for the less influential parameters.
S77-1 pavement thicknesses are of a standard composition with only the subbase thickness varying. Non-standard pavement structures are determined using the principle of material equivalence and the FAA provides range of material equivalence factors, of which the mid-range values are most commonly used. APSDS allows direct modelling of non-standard pavement structures. By comparing different APSDS pavements of equal structural capacity, implied material equivalences can be calculated. These APSDS implied material equivalences lie at the lower end of the ranges published by FAA. In order to obtain consistence between APSDS and the FAA guidance, the following material equivalence values are recommended:
* Asphalt for Crushed Rock. 1.3.
* Crushed Rock for Uncrushed Gravel. 1.2.
* Asphalt for Uncrushed Gravel. 1.6.
Proof rolling regimes remain an important part of the design and construction of flexible aircraft pavements. Historically, designers relied on Bousinesq's equation and the assumption of point loads on semi-finite homogenous materials to determine proof rolling regimes using stress as the indicator of damage. The ability of APSDS to generate stress, strain and deflection at any depth and any location across the pavement allows these historical assumptions to be tested. As the design of a proof rolling regime is one of comparing damage indicators modelled under aircraft loads to those under heavy roller loads, the historical simplifications are generally valid for practical design scenarios. Where project specific data is required, APSDS can readily calculate stresses induced by proof rollers and aircraft at any location and depth for comparison.
APSDS is a leading tool for flexible aircraft pavement thickness determination due to its flexibility, transparency and being free from bias. However, the following possible areas for improvement are considered worthy of future research and development:
* Improvements to the user interface.
* Ability to model aircraft masses as frequency distributions.
* Ability to copy stress with depth data to Excel(tm) spreadsheets.
* Ability to perform parametric runs.
* Inclusion of a reliability based design module.
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White, Gregory William. "An investigation of the Australian layered elastic tool for flexible aircraft pavement thickness design." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16663/.
Full textAbstract:
APSDS is a layered elastic tool for aircraft pavement thickness determination developed and distributed by Mincad Systems and based on the sister software Circly. As aircraft pavement thickness determination remains an empirical science, mechanistic-empirical design tools such as APSDS require calibration to full scale pavement performance, via the S77-1 curve. APSDS provides the unique advantage over other tools that it models all the aircraft in all their wandering positions, negating the need for designers to use pass to cover ratios and acknowledging that different aircraft have their wheels located at difference distances from the aircraft centerline. APSDS requires a range of input parameters to be entered, including subgrade modulus, aircraft types, masses and passes and a pavement structure. A pavement thickness is then returned which has 50% design reliability. Greater levels of reliability are obtained by conservative selection of input values. Whilst most input parameters have a linear influence on pavement thickness, subgrade modulus changes have a greater influence at lower values and less influence at higher values. When selecting input values, designers should concentrate their efforts on subgrade modulus and aircraft mass as these have the greatest influence on the required pavement thickness. Presumptive or standard values are generally acceptable for the less influential parameters. S77-1 pavement thicknesses are of a standard composition with only the subbase thickness varying. Non-standard pavement structures are determined using the principle of material equivalence and the FAA provides range of material equivalence factors, of which the mid-range values are most commonly used. APSDS allows direct modelling of non-standard pavement structures. By comparing different APSDS pavements of equal structural capacity, implied material equivalences can be calculated. These APSDS implied material equivalences lie at the lower end of the ranges published by FAA. In order to obtain consistence between APSDS and the FAA guidance, the following material equivalence values are recommended: * Asphalt for Crushed Rock. 1.3. * Crushed Rock for Uncrushed Gravel. 1.2. * Asphalt for Uncrushed Gravel. 1.6. Proof rolling regimes remain an important part of the design and construction of flexible aircraft pavements. Historically, designers relied on Bousinesq's equation and the assumption of point loads on semi-finite homogenous materials to determine proof rolling regimes using stress as the indicator of damage. The ability of APSDS to generate stress, strain and deflection at any depth and any location across the pavement allows these historical assumptions to be tested. As the design of a proof rolling regime is one of comparing damage indicators modelled under aircraft loads to those under heavy roller loads, the historical simplifications are generally valid for practical design scenarios. Where project specific data is required, APSDS can readily calculate stresses induced by proof rollers and aircraft at any location and depth for comparison. APSDS is a leading tool for flexible aircraft pavement thickness determination due to its flexibility, transparency and being free from bias. However, the following possible areas for improvement are considered worthy of future research and development: * Improvements to the user interface. * Ability to model aircraft masses as frequency distributions. * Ability to copy stress with depth data to Excel(tm) spreadsheets. * Ability to perform parametric runs. * Inclusion of a reliability based design module.
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Wong, Rachel Hiu Kam. "The making of construction workers : subjectivity, collectivity and the multi-layered subcontracting system in the Hong Kong construction industry /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?SOSC%202005%20WONG.
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García, García Alejandro. "Multiscale analysis of multi-layered tissues constructs : interfaces in the musculo-skeletal system based on tissue engineered osteotendinous junctions." Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2488.
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L’objectif de cette thèse était le développement d'un substitut bio-hybride pour la reconstruction du continuum tendon-os sur le principe de l’ingénierie tissulaire. Après une analyse bibliographique exhaustive des structures natives et de leur environnement, nous avons d'abord proposé la réalisation de chaque système séparément en utilisant des scaffolds en polycaprolactone réalises par electrospinning. Dans un premier temps, nous avons combiné l’electrospinning et l’electrospraying pour produire un scaffold composé de polycaprolactone et d’hydroapatite avec une structure en forme de nid d'abeille. Notre hypothèse était de doter le substitut d'une structure biomimétique favorisant l'adhésion, la colonisation et la différenciation cellulaire. L'analyse mécanique et biologique in vitro réalisée avec une lignée cellulaire progénitrice et des tests organotypiques a confirmé notre approche originale. Ensuite, le matériel ensemencé avec des cellules souches de moelle osseuse a été implanté avec succès par nos collaborateurs d'Amiens dans le but de traiter un défaut maxillo-facial chez un modèle de rongeur. Parallèlement, pour la reconstruction du tendon, nous avons réalisé différents scaffolds d'electrospinning, dont la taille et l'organisation (aléatoire/alignée) des fibres varient. Dans une perspective bio-inspirée, nous avons combiné les scaffold avec l'étirement dynamique pour reproduire l'entraînement physique. Sous ces stimulations mécaniques, établies d'abord avec la même lignée cellulaire progénitrice, nous avons démontré dans une deuxième étude que les CSM s'alignaient sur l'axe d'étirement et produisaient une matrice extracellulaire, ce qui a permis de conserver les propriétés mécaniques de la matrice biohybride pendant les deux semaines de la culture. Nous avons démontré que la différenciation cellulaire vers la lignée tendineuse et osseuse a été réalisée avec succès en l'absence de tout facteur de différenciation, étant spécifiquement lié aux propriétés des matériaux et à la mécanotransduction. Par conséquent, l'étape suivante, qui consiste à assembler les deux échafaudages avec une zone de transition, devrait conduire à la reconstruction de ce continuum osseux-tendonThe objective of this thesis was the development of a biohybrid substitute for the reconstruction of the bone-tendon continuum based on tissue engineering strategies. After an exhaustive bibliographic analysis of the native structures and their environment, we first proposed the realization of each system separately using electrospun polycaprolactone scaffolds. At first, we combined electrospinning with electrospraying techniques to produce a PCL-hydroapatite scaffold with honeycomb cavities. Our hypothesis was to provide the substitute with a biomimetic structure favoring cell adhesion, spreading and differentiation. The in vitro mechanical and biological analysis performed with a progenitor cell line and withorganotypic assays confirmed our original approach. Then, the material seeded with bone marrow stem cells was successfully implanted by our collaborators in Amiens with the objective of treating a maxillofacial defect in a rodent model. In parallel, for the tendon reconstruction, we investigated several electrospinning processes, varying fibers’ size and organization (random/aligned). In a bioinspired perspective, we combined the choice of the scaffold with dynamic stretching to reproduce physical training. Under those mechanical stimulations, established first with the same progenitor cell line, we demonstrated in a second study that MSCs aligned with the stretching axis and produced extracellular matrix, which in turn allowed to keep the mechanical properties of the biohybrid scaffold all over the 2 weeks of culture. We demonstrated that cell differentiation towards tendon and bone lineage was successfully achieved in the absence of any differentiation factor, being specifically related to materials properties and mechanotransduction. Therefore, the next step consisting in the assembly of both scaffolds with a transition area should lead to this bone-tendon continuum’s reconstruction
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Waqar, Hafiz Umer. "Comparison between .NET and Java EEImplementation of Cash & Bank System." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-23415.
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The demands of software engineering increases with everyday passed and every organization shows interest to work on daily routine work in the computerized system to improve efficiency and accuracy of data. Most of organization demands different kinds of computerized software solutions that developed in modern technologies. There are different software development technologies that is getting popular with the passage of time and provide high quality product to their user. It is not an easy to decide which technology choose to develop computerized system where most software falls. The primary purpose of thesis is to compare two different modern software development technologies by develop an application with same functional requirements. This thesis report will help to user for selection of software development technology. Cash and bank financial application is choose to develop using .NET and Java Enterprise Edition. Microsoft Visual Studio development environment is used for .NET development and NetBeans IDE is used for Java Enterprise Edition application. .NET framework contains many language that are interrelated with each other like C#, VB, J#, C++ and F#. Cash and bank application is develop in C# and Java programming languages and persistence storage of data is design in Microsoft SQL Server. Cash and bank application is develop with three tier architecture and layer approach. The syntax of .NET and Java Enterprise Edition is quite similar but procedure to establish connection, data retrieval and handling the data in different way. NET platform provide built in libraries, components and efficient user controls that helps for fast development in short period of time.
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Viljoen, Suretha. "Analysis of crosstalk signals in a cylindrical layered volume conductor influence of the anatomy, detection system and physical properties of the tissues /." Diss., Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-08082005-113739.
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Nakamura, Yasuyuki. "Existence of a compensation temperature of a mixed spin-2 and spin-5/2 Ising ferrimagnetic system on a layered honeycomb lattice." The American Physical Society, 2000. http://hdl.handle.net/2237/7150.
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Alsulami, Uthman Eyad N. [Verfasser], and J. [Akademischer Betreuer] Geis-Gerstorfer. "Influence of the coefficient of thermal expansion mismatch on the bond strength of bi-layered all ceramic system / Uthman Eyad N. Alsulami ; Betreuer: J. Geis-Gerstorfer." Tübingen : Universitätsbibliothek Tübingen, 2014. http://d-nb.info/1196877696/34.
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Wall, Corey James. "Establishing the age and duration of magmatism in large open-system layered intrusions from the high-precision geochronology of the Neoarchean Stillwater Complex and Paleoproterozoic Bushveld Complex." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58716.
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The Neoarchean Stillwater Complex (Montana, USA) and the Paleoproterozoic Bushveld Complex (South Africa), two of the world’s largest layered intrusions, have been cornerstones for the study of magmatic processes in the Earth’s crust. Mafic layered intrusions are natural laboratories for assessing the emplacement, crystallization, and cooling mechanisms of mantle-derived basaltic magmas. Most layered intrusions do not yet have robust geochronological frameworks from the base to the top of their stratigraphic successions. Zircon is recognized as a relatively common accessory mineral in the Stillwater and Bushveld intrusions and crystallized from highly fractionated interstitial melt at near-solidus temperatures (980-720°C). High-precision geochronologic frameworks established for both intrusions by U-Pb zircon dating, combined with trace element and hafnium isotope compositions of zircon, reveal extended durations of magmatism (3-5 million years) and non-stratigraphic or out-of-sequence ages for both intrusions. Dating of platinum group element deposits in both intrusions (J-M Reef, Stillwater; Merensky Reef, Bushveld) indicates that they are intrusion-wide time markers that crystallized synchronously over large distances (>300 km, Bushveld). The recognition that zircon can be successfully extracted from mafic-ultramafic rocks associated with magmatic ore deposits provides new opportunities for assessing the timing and duration of mineralization processes in layered intrusions worldwide. Zircon from a thick anorthosite horizon in the Stillwater Complex has been identified as a reference material for U-Pb geochronology of Archean rocks (>2.5 Ga) and fills an important gap in the geologic timescale for the application of precise and accurate U-Pb geochronology. Collectively, the dating results indicate that both the Stillwater Complex and Bushveld Complex do not represent the products of progressively crystallized magma chambers but instead formed as stacks of amalgamated sills representing repeated injections of magma at different stratigraphic levels. These conclusions call into question current concepts regarding the origin of layered intrusions and challenge us to rethink our understanding of the timescales of magma processes throughout Earth history.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
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Helmer, Markus Verfasser], Theo [Akademischer Betreuer] [Geisel, and Fred [Akademischer Betreuer] Wolf. "Attention: A Complex System : From the Intricate Modulation of Tuned Responses Towards a Layered Cortical Circuit Model / Markus Helmer. Betreuer: Theo Geisel. Gutachter: Theo Geisel ; Fred Wolf." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://d-nb.info/1080609962/34.
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Almasarwah, Najat E. MASARWAH. "Multi-Stage Cellular Manufacturing System Design under Certain and Uncertain Conditions." Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1605028865095297.
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Weisbach, Tobias, Jens Sumpf, and Christian Bumm. "Thermoplastic Multilayer Slide-Foil." Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-231676.
Full textAbstract:
The training of movement procedures to increase the skills of athletes is a fundamental part of competitive sports. A realistic training, supported by technical equipment provides athletes a better success of training and is requested by trainers and training centers all over the world. Especially in winter sports, like luge or bob, a realistic training simulation is not always possible and demands adaptations of specific training procedures. As a part of this article, a new multilayer slide-foil will be presented, which allows athletes an even more realistic training. For this purpose the structure and production process of the foil composite will be shown, as well as results of the tribological behaviour of the foilDas Training von Bewegungsabläufen, zur Steigerung von Fähigkeiten, ist ein fundamentaler Bestandteil im Leistungssport. Ein realistisches Training, unterstützt durch technische Systeme, ermöglicht es Athleten optimale Trainingserfolge zu erzielen und wird dementsprechend von Trainern und Leistungszentren überall auf der Welt gewünscht. Insbesondere in Wintersportarten, wie z. B. Rennrodeln oder Bobfahren, kann dies allerdings nur bedingt realisiert werden und erfordert oftmals Abstriche bei der Trainingsgestaltung. Im Rahmen dieses Beitrags wird daher eine mehrschichtige Verbundfolie vorgestellt, welche den Athleten ein realistischeres Training ermöglichen soll. Hierzu werden zum einen der Aufbau und die Herstellung des Folienverbundes erläutert sowie tribologische Untersuchungsergebnisse präsentiert
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Pech, David. "Cloud Framework on Infrastructure as a Service." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236185.
Full textAbstract:
Práce se zabývá podrobnou analýzou požadavků na moderní aplikační rámec pro prostředí cloud. Za pomoci standardních návrhových vzorů a technik připravuje teoretický základ a pravidla, která musí uvnitř rámce platit. V práci je realizována referenční implementace a připravena demonstrační aplikace středního rozsahu, aby představila výhody plynoucí z užití frameworku.
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Heath, Gerhardus. "Dynamic reconfigurable platform for swarm robotics." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6814.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011.ENGLISH ABSTRACT: Swarm intelligence research was inspired by biological systems in nature. Working ants and bees has captivated researchers for centuries, with the ant playing a major role in shaping the future of robotic swarm applications. The ants foraging activity can be adapted for different applications of robotic swarm intelligence. Numerous researchers have conducted theoretical analysis and experiments on the ants foraging activities and communication styles. Combining this information with modern reconfigurable computing opens the door to more complex behaviour with improved system dynamics. Reconfigurable computing has numerous applications in swarm intelligence such as true hardware parallel processing, dynamic power save algorithms and dynamic peripheral changes to the CPU core. In this research a brief study is made of swarm intelligence and its applications. The ants' foraging activities were studied in greater detail with the emphasis on a layered control system designed implementation in a robotic agent. The robotic agent’s hardware was designed using a partial self reconfigurable FPGA as the main building element. The hardware was designed with the emphasis on system flexibility for swarm application drawing attention to power reduction and battery life. All of this was packaged into a differential drive chassis designed specifically for this project.
AFRIKAANSE OPSOMMING: Die motivering vir swerm robotika kom van die natuur. Vir eeue fassineer swerm insekte soos bye en miere navorsers. Dit is verstommend hoe ’n groep klein en nietige insekte sulke groot take kan verrig. Die mier speel ‘n belangrike rol en is die sentrale tema van menige publikasies. Die mier se kos-soek aktiwiteit kan aangepas word vir swerm robotika toepassings. Hierdie aktiwiteit vervat verskeie sleutel konsepte wat belangrik is vir robotika toepassings. Deur bv. die mier se aktiwiteite te kombineer met dinamies herkonfigureerbare hardeware, kan meer komplekse gedrag bestudeer word. Die stelsel dinamika verbeter ook, aangesien dit nou moontlik is om sekere take in parallel uit te voer. Deur ’n interne prosesseerder in die herkonfigureerbare hardeware in te sluit, is dit nou vir die stelsel moontlik om homself te verander tydens taak verrigting. Komplekse krag bestuur gedrag is ook moontlik deurdat die prosesseerder die spoed en rand apparaat kan verander soos benodig. ‘n Verdere voordeel is dat die stelsel aanpasbaar is en dus vir verskeie navorsingsprojekte gebruik kan word. In hierdie navorsing word ’n literatuur studie van swerm robotika gemaak en word daar ook na toepassings gekyk. Met die klem op praktiese implementering, word die mier se kos-soek aktiwiteit in detail ondersoek deur gebruik te maak van ’n laag beheerstelsel. In hierdie laag beheerstelsel verteenwoordig elke laag ’n hoër vlak gedrag. Stelsel aanpasbaarheid en lae kragverbruik speel ’n deurslaggewende rol in die ontwerp, en om hierdie rede vorm ’n FPGA die hart van die sisteem.
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Younes, Sinaki Roohollah. "Financial Analysis and Global Supply Chain Design : A Case Study of Blood Sugar Monitoring Industry." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1509119632628001.
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Abdurrhman, Ahmed B. M. "Error resilient video communications using high level M-QAM : modelling and simulation of a comparative analysis of a dual-priority M-QAM transmission system for H.264/AVC video applications over band-limited and error-phone channels." Thesis, University of Bradford, 2010. http://hdl.handle.net/10454/4913.
Full textAbstract:
An experimental investigation of an M level (M = 16, 64 and 256) Quadrature Amplitude Modulation (QAM) transmission system suitable for video transmission is presented. The communication system is based on layered video coding and unequal error protection to make the video bitstream robust to channel errors. An implementation is described in which H.264 video is protected unequally by partitioning the compressed data into two layers of different visual importance. The partition scheme is based on a separation of the group of pictures (GoP) in the intra-coded frame (I-frame) and predictive coded frame (P frame). This partition scheme is then applied to split the H.264-coded video bitstream and is suitable for Constant Bit Rate (CBR) transmission. Unequal error protection is based on uniform and non-uniform M-QAM constellations in conjunction with different scenarios of splitting the transmitted symbol for protection of the more important information of the video data; different constellation arrangements are proposed and evaluated to increase the capacity of the high priority layer. The performance of the transmission system is evaluated under Additive White Gaussian Noise (AWGN) and Rayleigh fading conditions. Simulation results showed that in noisy channels the decoded video can be improved by assigning a larger portion of the video data to the enhancement layer in conjunction with non-uniform constellation arrangements; in better channel conditions the quality of the received video can be improved by assigning more bits in the high priority channel and using uniform constellations. The aforementioned varying conditions can make the video transmission more successful over error-prone channels. Further techniques were developed to combat various channel impairments by considering channel coding methods suitable for layered video coding applications. It is shown that a combination of non-uniform M-QAM and forward error correction (FEC) will yield a better performance. Additionally, antenna diversity techniques are examined and introduced to the transmission system that can offer a significant improvement in the quality of service of mobile video communication systems in environments that can be modelled by a Rayleigh fading channel.
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Abdurrhman, Ahmed B. M. "Error relilient video communications using high level M-QAM. Modelling and simulation of a comparative analysis of a dual-priority M-QAM transmission system for H.264/AVC video applications over band-limited and error-phone channels." Thesis, University of Bradford, 2010. http://hdl.handle.net/10454/4913.
Full textAbstract:
An experimental investigation of an M level (M = 16, 64 and 256) Quadrature Amplitude Modulation (QAM) transmission system suitable for video transmission is presented. The communication system is based on layered video coding and unequal error protection to make the video bitstream robust to channel errors. An implementation is described in which H.264 video is protected unequally by partitioning the compressed data into two layers of different visual importance. The partition scheme is based on a separation of the group of pictures (GoP) in the intra-coded frame (I-frame) and predictive coded frame (P frame). This partition scheme is then applied to split the H.264-coded video bitstream and is suitable for Constant Bit Rate (CBR) transmission. Unequal error protection is based on uniform and non-uniform M-QAM constellations in conjunction with different scenarios of splitting the transmitted symbol for protection of the more important information of the video data; different constellation arrangements are proposed and evaluated to increase the capacity of the high priority layer. The performance of the transmission system is evaluated under Additive White Gaussian Noise (AWGN) and Rayleigh fading conditions.
Simulation results showed that in noisy channels the decoded video can be improved by assigning a larger portion of the video data to the enhancement layer in conjunction with non-uniform constellation arrangements; in better channel conditions the quality of the received video can be improved by assigning more bits in the high priority channel and using uniform constellations. The aforementioned varying conditions can make the video transmission more successful over error-prone channels. Further techniques were developed to combat various channel impairments by considering channel coding methods suitable for layered video coding applications. It is shown that a combination of non-uniform M-QAM and forward error correction (FEC) will yield a better performance. Additionally, antenna diversity techniques are examined and introduced to the transmission system that can offer a significant improvement in the quality of service of mobile video communication systems in environments that can be modelled by a Rayleigh fading channel.
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Forbes, Michael F. "Ultrasonic characterization of layered composite systems." Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/5633.
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Goddard, Paul. "Magnetotransport studies of layered metallic systems." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275491.
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Lazar, Laura [Verfasser]. "Fe/Pb layered systems / Laura Lazar." Bochum : Universitätsbibliothek, Ruhr-Universität Bochum, 2003. http://d-nb.info/116793296X/34.
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Morgan, Bo. "A substrate for accountable layered systems." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/91854.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 193-196).
A system built on a layered reflective cognitive architecture presents many novel and difficult software engineering problems. Some of these problems can be ameliorated by erecting the system on a substrate that implicitly supports tracing the behavior of the system to the data and through the procedures that produced that behavior. Good traces make the system accountable; it enables the analysis of success and failure, and thus enhances the ability to learn from mistakes. This constructed substrate provides for general parallelism and concurrency, while supporting the automatic collection of audit trails for all processes, including the processes that analyze audit trails. My system natively supports a Lisp-like language. In such a language, as in machine language, a program is data that can be easily manipulated by a program, making it easier for a user or an automatic procedure to read, edit, and write programs as they are debugged. Constructed within this substrate is an implementation of the bottom four layers of an Emotion Machine cognitive architecture, including built-in reactive, learned reactive, deliberative, and reflective layers. A simple natural language planning language is presented for the deliberative control of a problem domain. Also, a number of deliberative planning algorithms are implemented in this natural planning language, allowing a recursive application of reflectively planned control. This recursion is demonstrated in a fifth super-reflective layer of planned control of the reflective planning layer, implying N reflective layers of planned control. Here, I build and demonstrate an example of reflective problem solving through the use of English plans in a block building problem domain. In my demonstration an AI model can learn from experience of success or failure. The Al not only learns about physical activities but also reflectively learns about thinking activities, refining and learning the utility of built-in knowledge. Procedurally traced memory can be used to assign credit to those thinking processes that are responsible for the failure, facilitating learning how to better plan for these types of problems in the future.
by Bo Morgan.
Ph. D.
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Chiu, Hon-sun, and 邵漢新. "Receiver-driven layered multicast over IP networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B29735853.
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Van, der Westhuizen Maria Jacoba. "The engineering and optimization of expression of rotavirus-like particles in insect cells using a South African G9P[6] rotavirus strain / by Maria J. van der Westhuizen." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9852.
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Rotavirus infection causes gastroenteritis, specifically severe gastroenteritis, affecting children younger than five globally, regardless of hygiene and water quality. Current licensed, live, attenuated vaccines do not contain the G9 genotype, which is a prevalent rotavirus strain circulating in sub-Saharan Africa, a region that carries a high rotavirus disease burden. Rotavirus-like particles (RV-VLPs) is an attractive non-live vaccine candidate, which has shown promising results in animal studies. Previously, dsRNA was extracted from a stool sample containing a South African human G9P[6] neonatal strain, and amplified cDNA using a sequence-independent procedure. The consensus sequence was obtained for the genome segments using 454® pyrosequencing. The insect-cell-codon-optimized genome segments 2 (VP2), 4 (VP4), 6 (VP6) and 9 (VP7) were cloned into a modified pFASTBACquad vector (pFBq). Several combinations of the genome segments were cloned to produce double-layered particles (DLP; pFBqVP2VP6) or triple-layered particles (TLP; pFBqVP2VP6VP7). In the current study, a ΔTLP (pFBqdVP2-VP8*VP6VP7) construct was generated. The first 92 amino acids of VP2 are not necessary for the conformation of recombinant RV-VLPs. The ORF of VP8*, which contains immune important epitopes, was fused to the 5’ end of the dVP2 coding region resulting in a dVP2-VP8* fused protein which was expressed in the presence of VP6 and VP7 to produce ΔTLPs. The Bac-to-Bac® Baculovirus Expression System and Spodoptera frugiperda (Sf) 9 insect cells were used for expression. All the proteins were successfully expressed. VP2, VP6, VP4 and the dVP2-VP8* fused protein were visible on Coomassie stained SDS-PAGE. Expression of VP7 could only be confirmed with western blot analysis. Particle formation, as assessed by transmission electron microscopy (TEM), was observed for DLPs. No TLPs of dVP2-8*/6/7 or VP2/6/7 were visualized due to the lower expression level of VP7 and the lack of calcium supplements during the assembly process. In conclusion, it was possible to produce RV-DLPs derived from the consensus sequence determined for a G9P[6] rotavirus directly from stool without prior propagation in cell culture or virus isolation. This strain contains both the G9 and P[6] genotypes that are currently prevalent in sub-Saharan Africa.Thesis (MSc (Biochemistry))--North-West University, Potchefstroom Campus, 2013.
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Sucharitakul, Sukrit. "2D ELECTRONIC SYSTEMS IN LAYERED SEMICONDUCTING MATERIALS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1491497351482802.
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Fitzpatrick, Paul G., and paul g. fitzpatrick@team telstra com. "Traffic modelling and performance of layered cellular networks with overflow." Swinburne University of Technology, 1997. http://adt.lib.swin.edu.au./public/adt-VSWT20060119.093920.
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This thesis reports on an investigation into the teletraffic modelling and performance of layered cellular networks that use overflow for new call and handover attempts in order to improve system performance It addresses the important problems how to model and analyse overflow in large cellular networks so that the overall impact across the network can be evaluated, the overflow policies that can be used with new calls and handovers to improve network performance and how these policies perform under a range of conditions.
The general problem of modelling overflow in cellular networks is considered at length and from this it is concluded that the use of overflow in existing schemes such as directed retry, reuse partitioning and overlaid cells can also be described by the simple concepts of intra and inter layer overflow Using these concepts the author formulates the problem of overflow in layered networks as a subset of the general problem of overflow with multiple overflow routes and restricted overflow. This leads to the derivation of the mean and variance of the overflow traffic from a cell with multiple handover routes and restricted handover from the two-dimensional birth death model of the system.
These expressions for the mean and variance are used in conjunction with the Equivalent Random Theory and splitting formulae in the development of the Splitting Formula Method or SF Method. The accuracy of three splitting formulae and a simple Poisson approximation are investigated and compared with simulation. From this we conclude that the splitting formulae of Akimaru and Takahashi and Wallstrom provide the best overall result. This method is used to solve the general problem of multiple user classes for an example two layer network. This leads to conclusions on the complex relationship between cell capacity, the proportion of uses that can access the microcells and the proportion of users that can overflow from the microcell to the macrocell.
The Modified Splitting Formula Method is an extension of the SF Method that includes handovers and overflow for handovers. A user perceived measure of the effect of new call and handover blocking described by the probability of call failure augments the Modified SF method. This is then used to analyse five new call overflow policies for a three layer network under conditions of extended handover, restrictions on handover for calls in cells at the edge of layers and spatial offset between the peak of the traffic demand and the cell layout. The results give new and valuable insight into the behaviour of layered cellular networks with overflow and the trade-offs in performance that exist when designing and operating these networks.
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Breier, Annette. "Grundlegende Untersuchungen zur Integration eines Wirkstofffreisetzungssystems in ein textiles Knochenimplantat am Beispiel des Antibiotikums Gentamicin." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-181922.
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Das bei der Sanierung von großen segmentalen Knochendefekten bestehende Risiko einer fremdkörperassoziierten Infektion soll durch die Integration eines Wirkstofffreisetzungssystems in ein bestehendes textiles Knochenimplantat gemindert werden. Durch Immobilisierung des Wirkstoffs in eine degradierbare Polymermatrix wird eine zeitlich verzögerte Freisetzung bewirkt. Als Wirkstofffreisetzungssystem wird die Kombination von Polylactid (PLA) bzw. Poly(Lactid-co-Glycolid) (PLGA) als Matrixpolymer mit dem Antibiotikum Gentamicin als Wirkstoff untersucht, welches durch Beschichtung der textilen Scaffolds mittels Dip-Coating eingebracht werden soll. Es stehen die drei Beschichtungsmethoden „Suspension“, „Emulsion“ und „Schichtaufbau“ zur Auswahl, die jeweils über eigene Parameter zur Beeinflussung des Freisetzungsprofils verfügen. Die Methode „Suspension“ und die damit verbundenen Einflussfaktoren Korngröße, Korngrößenverteilung sowie Masseanteil des Antibiotikums und Schichtdicke der aufgetragenen Polymerschicht wurde als die günstigste herausgearbeitet. Im Teil II dieser Arbeit wird diese soweit optimiert, dass nahezu über den gesamten geforderten Zeitraum die festgelegte notwendige Dosierung aufrechterhalten werden kann. Erste in vitro Versuche weisen auf eine gute Zellverträglichkeit sowie eine ausreichende mikrobielle Wirksamkeit hinTo reduce the risk of infection in the treatment of long bone defects, a novel embroidered bone implant is to be provided with an antibiotic drug delivery system. Prolonged and controlled drug release can be achieved by coating the thread material with antibiotics incorporated in a degradable polymer matrix. The chosen drug delivery system is composed of polylactide acid (PLA) or poly(lactide-co-glycolide) acid (PLGA) as matrix polymer and the antibiotic gentamicin. It is integrated into the textile structure by dip-coating providing the three different methods suspension, emulsion and layered. Each method bears its appropriate parameters to influence the releasing profile. The suspension-method and its parameters grain size and grain size distribution as well as mass fraction of the antibiotic and the coating thickness could be proved as the most feasible. In part II of this essay the chosen coating set-up gets optimized so that a drug release nearly along the whole required term can be achieved. Preliminary in vitro studies show a good cell tolerance besides a sufficient microbial efficacy
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Ajemian, Stephen P. "Modeling and evaluation of aerial layer communications system architectures." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90705.
Full textAbstract:
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 90-91).
Airborne networks are being developed to provide communications services in order to augment space-based and terrestrial communications systems. These airborne networks must provide point to point wireless communications capabilities between aircraft and to ground-based users. Architecting airborne networks requires evaluating the capabilities offered by candidate aircraft to operate at the required altitudes to bridge communications among ground users dispersed over large geographic areas. Decision makers are often faced with choices regarding the type and number of aircraft to utilize in an airborne network to meet information exchange requirements. In addition, the type of radio required to meet user needs may also factor into the architecture evaluation for an airborne network. Aircraft and radio design choices must be made under cost constraints in order to deliver capable communications architectures at an acceptable cost. Evaluating communications architectures is often conducted with modeling and simulation. However, evaluations typically focus on specific network configurations and can become intractable when varying design variables such as aircraft and radio types due to the complexity of the trade space being analyzed. Furthermore, the growth in choices for design variables (such as additional aircraft types) can lead to enormous growth in the number of feasible candidate architectures to analyze. The methodology developed and presented herein describes an approach for evaluating a large number of architecture combinations which vary on aircraft type and radio type for representative airborne networks. The methodology utilizes modeling and simulation to generate wireless communications performance data for candidate aircraft and radio types and enumerates a large trade space through a computational tool. The trade space is then evaluated against a multi-objective decision model to rapidly down-select to a handful of candidate architectures for more detailed analysis. The results of this analysis provide effective tools for reducing the complex trade space to a tractable number of architectures to make an informed architectural decision with no prior articulation of preferences for performance measures. For the notional concept of operation analyzed, the number of feasible architectures was approximately 500,000 for each of the two radio types examined. The decision model implemented reduced the feasible architectures to approximately 50 near-optimal architectures for each radio type. From this manageable set of near-optimal architectures, an analysis is conducted to evaluate marginal benefits versus cost to further reduce the candidate architectures to 3 architectures for each radio type. From these remaining architectures, detailed analysis and visualization can be conducted to aid decision makers in articulating preferences and identifying a single "best" architecture based on mission needs. The enumeration of the trade space using the computational tool and multi-objective decision model is highly flexible to incorporating new constraints and generating new candidate architectures as stakeholder preferences become clearer. The trade space enumeration and decision model can be conducted rapidly to down-select large trade spaces to a tractable number of communications architectures to inform an architectural recommendation.
by Stephen P. Ajemian.
S.M. in Engineering and Management
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Förster, Stefan. "A formal framework for modelling component extension and layers in distributed embedded systems /." Dresden : TUDpress, 2007. http://www.loc.gov/catdir/toc/fy0803/2007462554.html.
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Cotuk, Umit. "Scattering from multi-layered metamaterials using wave matrices." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FCotuk.pdf.
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Du, Jianxuan. "Layered Space-Time Structure for MIMO-OFDM Systems." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7204.
Full textAbstract:
The low complexity of layered processing makes the layered structure a promising candidate for MIMO systems with a large number of transmit antennas and higher order modulation. For broadband systems, orthogonal frequency division multiplexing (OFDM) appears promising for its immunity against delay spread. In addition, OFDM is especially suitable for frequency selective MIMO systems since the introduction of orthogonal subcarriers makes system design and implementation as simple as those for flat fading channels. Therefore, the combination of layered structure with OFDM is a promising technique for high-speed wireless data transmission.
The proposed research is focused on the layered structure for MIMO-OFDM systems, where several techniques are proposed for performance enhancement, namely, channel estimation based on subspace tracking, parallel detection of group-wise space-time codes by predictive soft interference cancellation, quasi-block diagonal low-density parity-check codes (LDPC) coding and statistical data rate allocation for layered systems.
For MIMO-OFDM systems, rank reduction by some linear transform matrix is necessary for channel estimation. In the proposed research, we propose a channel estimation algorithm for MIMO-OFDM systems, which uses the optimum low-rank channel approximation obtained by tracking the frequency autocorrelation matrix of the channel response.
Then parallel detection algorithm is proposed for a modified layered system with group-wise space-time coding, where the structure of particular component space-time code trellises is exploited using partial information from the Viterbi decoder of the simultaneously decoded interfering component codes.
Next we incorporate the layered structure with LDPC to develop a quasi-block diagonal LDPC space-time structure. The lower triangular structure of the parity check matrix introduces correlation between layers. Each layer, as a part of the whole codeword, can be decoded while taking information from other undetected layers to improve the decoding performance.
In the end, a modified layered structure is proposed where the layer detection order is fixed and the data rate for each layer is allocated based on the detection order and channel statistics. With Gaussian approximation of layer capacities, we derive the optimum data rate allocation.
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Bridgeman, Catherine H. "Computational studies of layered materials and aqueous systems." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388760.
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Iqbal, Muhammad Ahsan. "Layered double hydroxide based smart protective coating systems." Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/302211.
Full textAbstract:
Corrosion protection of aluminum and its alloys is a challenging subject to widen the service life of material and its industrial usage. Numerous protective measures have been employed for the corrosion protection of aluminum alloys. Chromate based coatings system was in use for a long time to protect the light metals alloys, but after the ban on Chromates based coating (2017) in European Union due to strict health and safety rules and regulations, there is a need to develop environmentally friendly, greener coating systems to functionalize aluminum surface and to provide sufficient chemical and electrochemical stability against the aggressive environment and can possess multifunctional properties. The present study investigates the designing of the "Layered double hydroxide (LDHs)" based system for the protection of AA6082 alloy, which until now has given not much attention. LDHs demonstrate unique characteristic which helps to obtain special microstructure to attain multi-functional properties along with improved corrosion resistance properties. The novel environmentally friendly “Layered double hydroxides” (LDHs) thin films were synthesized, through chemical conversion approach, directly on the aluminum AA6082 substrates, and precisely characterized by various physical and electrochemical approaches. The defining of proper synthetic conditions for the synthesis of LDH is problematic due to the influence of certain parameters which made an impact not only on the structural properties of the LDHs but also on the anticorrosion behavior of LDH. This study focused on the thorough investigation of the optimization of synthetic conditions for LDHs and their effect on LDH assembly, surface morphology, thickness, interaction with corrosion inhibitors to control the corrosion resistance properties.
The first step of the work is to control the synthetic parameters to obtain unique LDHs structural geometries for the development of anti-corrosion thin films. The addition of a complexation agent i.e. urea, ammonium hydroxide was also introduced to obtain distinct surface morphologies. Various LDHs classes were developed on the aluminum substrate in that scenario, for example, MgAl-LDH, ZnAl-LDH, NiAl-LDH, CaAl-LDH, and a detailed comparative study is reported about the dependency of structural- electrochemical relationships. The aim was to find the ideal films' properties, which leads to widening the potential window of corrosion resistance films in the defined electrolytes. To analyses high-temperature applications, calcination of developed MgAl-LDHs is investigated to understand the effect of thermal treatments on the LDHs structure, basal spacing, intercalated anions, and its effects on corrosion resistance properties.
The second part of the thesis is focused on the modification of the LDHs. Initially, graphene is introduced inside the LDHs network due to graphene chemical inertness and electrochemical characteristics. A thorough investigation is reported about the interaction of graphene with LDHs, and the ability of graphene to tune the properties of LDH for the designing of improved protective LDHs films. Specifically, the research focused on the use of graphene to seal the micropores of LDHs films to promote barrier properties and explore the graphene interaction with the LDHs. Overall, the impedance modulus of the films was compared with the results of virgin LDHs and the efficacy of the graphene-based LDH system is described.
In the third part of the thesis, cerium modified LDHs are developed on the anodic AA6082 substrate to understand the self-healing characteristic of the modified LDHs based system and their long-term protective ability. Rare earth elements found to have a significant inhibiting effect and are the object of considerable scientific interest, exhibiting nontoxic nature. Conceptually, the cerium modified LDH grown on the anodized surface can seal the micropores of the anodized surface (improved barrier properties), while LDHs themselves provide active protection via entrapment of aggressive species and through self-healing properties. The final part of the thesis comprises the introduction of a double-doped effect, where cerium was introduced inside LDHs galleries and further doped with superhydrophobic species to obtain compact LDH multifunctional films with enhanced LDHs corrosion resistance properties. In the case of the double doped cerium-based LDHs films, the improvement in the corrosion resistance properties were observed during the long-term EIS measurements, while superhydrophobic, self-cleaning characteristics, and UV radiation impact on coating was thoroughly reported. Double doped LDHs lead to an influential increment in corrosion resistance properties, durability, and long-term stability.
Furthermore, the role of LDHs as adsorbents for the heavy metals present in drinking water is also reported. Different adsorption models are studied, and adsorption kinetics is reported to understand the adsorption behavior of LDHs against arsenic impurities. The results depicted the successful removal of arsenic from drinking water with high efficiency than traditionally used materials.
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Carr, Joel Matthew. "CONFINED LAYERED POLYMERIC SYSTEMS FOR PACKAGING ANDCAPACITOR APPLICATIONS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1363104386.
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