196,381 research outputs found
Protected group control system for mobile robots
No full textThe purpose of this work is to present a secure group control system for ground mobile robots. The paper includes the analysis of existing group control algorithms, a description of the implementation of some of the algorithms, their testing and analysis of characteristics. When we solve the problem, we adhere to the following aspects: The multivariance of simulated situations, the feasibility of algorithms within the framework of existing computer systems and their applicability within the framework of real group control systems, the use of cryptographic information security tools using distributed methods, the development of a model for group control of robots and testing of developed solutions should be carried out using a simulator, approbation of the developed solutions is carried out using a full-scale model, which includes a set of single-board computers, between which a wireless network is organized, robots perform the main task of analyzing the terrain and building a terrain map, while the terrain map should be distributed between robots and updated periodically, robots must be able to avoid obstacles and collisions with each other, perform the task of moving towards the goal and the task of following the group leader. Security solutions must ensure the property of integrity, proof of authorship, and trust in the data. Implementing the choice of the group leader must also provide the ability to select a trusted entity as the group leader
Physico-chemical properties of nanocrystalline apatites: Implications for biominerals and biomaterials
No full textNanocrystalline apatites play an important role in biomineralisation and they are used as bioactive biominerals for orthopaedic applications. One of the most interesting characteristics of the nanocrystals, evidenced by spectroscopic methods, is the existence of a structured surface hydrated layer, well developed in freshly formed precipitates, which becomes progressively transformed into the more stable apatitic lattice upon ageing in aqueous media. The hydrated layer is very fragile and irreversibly altered upon drying. Several routes leading to different apatite compositions are found in biological systems. The loosely bound ions of the hydrated layer can be easily and reversibly substituted by other ions in fast aqueous ion exchange reactions. These ions can either be included in the growing stable apatite lattice during the ageing process or remain in the hydrated layer. The adsorption properties of nanocrystals appear to be strongly dependent on the composition of the hydrated layer and on ageing. The surface reactivity of the apatite nanocrystals can play a part in different biomaterials and could explain the setting reactions of biomimetic calcium phosphate cements and the possibility of obtaining adherent nanocrystalline coatings on different substrates
POtenzialità della tecnica EIS per il rilievo del degrado delle barriere termiche sottoposte a prove di ossidazione ciclica
No full textQuesto lavoro è dedicato allo studio dell’evoluzione dei rivestimenti tipici delle parti calde delle turbine a gas,
costituiti da uno strato metallico e da uno ceramico di zirconia parzialmente stabilizzata con ittria, con funzione di barriera termica. Vengono dapprima mostrati i risultati di una campagna sperimentale svolta su campioni invecchiati in prove di ossidazione ciclica a due diverse temperature e sottoposti ad analisi metallografiche per individuare i meccanismi di degrado indotti dall’esposizione alle elevate temperature e dall’azione di ripetuti cicli termici. Viene poi presa in esame la possibilità di applicare una tecnica di controllo non distruttivo
(la spettroscopia d’impedenza elettrochimica) per rilevare il grado crescente di danneggiamento. La variazione degli spettri d’impedenza ottenuti ha confermato la sensibilità della tecnica allo spessore dello strato ceramico, alle sue caratteristiche (porosità e microcriccatura) e alla formazione dello strato di ossido all’interfaccia metallo/ceramico. I risultati ottenuti vengono discussi alla luce delle analisi metallografiche quantitative e delle
informazioni reperibili in letteratura. Si suggeriscono infine alcune linee di ulteriore sviluppo
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
New Russian Entrepreneurship: Sources of Formation and Strategy of Social Action
No full textThe present article uses materials of the joint French-Russian study "New Social Movements in Russia." Scientific supervision on the French side was provided by professors A. Touraine, M. Wiewiórka, and A. Berelovitch; on the Russian side, by professors L. Gordon and E. Klopov. M. Wiewiórka, N. Lapina, and I. Mintusov worked together with a group of entrepreneurs and the article's author.
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
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