197,591 research outputs found
Development and testing of a collision avoidance algorithm for industrial applications
No full textSafe interaction of the operator and the cobot in the co-working space is one fundamental requirement for introducing automation in small and medium enterprises characterized by unstructured cell layouts. In addition to the exploitation of cobots, a fully safe interaction requires the adoption of collision avoidance systems, to enable the real-time re-planning of the end-effector trajectories thus avoiding to stop the machine in case of collision with humans. This is fundamental for industrial applications, in order to maintain the production rate as constant as possible even in unstructured production environments. However, collision avoidance applications in actual industrial production cells are still limited, due to some limitations which are not yet completely solved. It is indeed still likely to happen that the recalculation of the obstacle-free trajectory takes a too long time, not compatible with industrial applications. This paper describes the development of a collision avoidance program using the Lazy PRM∗ algorithm. The program is tested on a physical robot, the Mitsubishi Melfa RV-5AS-D, to perform some exemplary pick and place tasks. The developed algorithm can alter online, during the execution, the road-map from dense to sparse in those cases in which the search for an alternative trajectory is detected to take too long time. Compared to other commercial collision avoidance systems, in which the evaluation of road-maps can only be done offline once and for all, this feature would prevent the robot to get stucked in case a feasible solution is not found in a fast enough way. Furthermore, the developed program guarantees greater flexibility in creating the road-map, trying to match the user's needs, and eliminating the superfluous parts of the road-map to reduce computational time. This marks a difference with present-day solutions for commercial collision avoidance systems which, to the author knowledge, connects all the nodes together
Islamic vs. conventional funds: a comparative analysis over the financial crisis: evidence from the Middle East
No full textThe findings of over-or-under performance of fund managers across the crisis periods are mixed. By analyzing the monthly data for 90 mutual funds chosen from ‘Kuwait, the United Arab Emirates, the Kingdom of Bahrain, Qatar, and Sultanate of Oman’ as a-five-Gulf countries, this paper employs Jensen’s alpha and Treynor & Mazuy models for the period of 2007-2012 to offer a comprehensive investigation for the fund managers’ capabilities of market timing and selectivity. It explores these two skills during and after the Financial Crisis (FC) period of 2007-2008, in addition to inspecting the relative differences in performance between equity conventional mutual funds (CMFS) and Islamic ones. The results show no evidence of over-or-under performance even for the overall period of 2007-2012 or for the down-market period of 2007-2008, where there are no structural changes for the regression line across the two sub-periods. But, it reveals the superiority of equity CMFS performance in Kuwait alone, where, the results of the cross-section analysis for the differences in means and standard deviations of Alpha and Beta coefficients are statistically significant for the overall period. Thus, it seems that if the investors cannot gain superior returns by investing in the Gulf mutual funds in general, they may attain a comparative advantage by investing in the conventional funds against the Islamic ones especially in Kuwait. It also implies that the ethical screening, which is adopted by the Islamic funds of Kuwait, already limits their diversification opportunities and then adversely affects their performance
Supercapacitance performance of novel core/shell poly(m-toluidine)/(Co-Ni) nanoplatelets/nanoneedles nanocomposite
No full textPoly(m-toluidine) (PmT) is a promising polymer material for many applications due to its high electrical conductivity, stability, and ease of synthesis. This work uses PmT/(Co-Ni) nanoplatelets/nanoneedles core/shell composite as an electrode for designing a high-performance supercapacitor. Firstly, nanoneedles of basic Co-Ni compounds composed of cobalt nickel oxide [CNO; Co1.29Ni1.71O4] and cobalt carbonate hydroxide hydrate [CCHH; Co(CO3)0.5(OH)0·.11H2O] were prepared via hydrothermal process. Then, the poly(m-toluidin) [PmT; C7H9N] nanoplatelets were grown on the (Co-Ni) nanoneedles by the in-situ oxidation polymerization method. The elemental composition, crystal structure, and morphology of the PmT/(Co-Ni) electrode were characterized by physicochemical characterization techniques. The supercapacitance performance of the PmT/(Co-Ni) electrode was measured by using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy in HCl solution. The results show that the specific capacitance of the PmT/(Co-Ni) electrode was measured at a current density of 0.6 A/g reaching 308F/g. while the values of specific power density and specific energy are 720 W/kg and 15.4 W h/kg, respectively. Moreover, the PmT/(Co-Ni) electrode exhibits long-term stability and retained about 98% of its starting capacitance value after thousand cycles. The remarkable electrochemical execution recorded could be ascribed to unique nanoplatelets/nanoneedles architectures and conductive PmT polymer. These encouraging results refer to good performance and high stability of the PmT/(Co-Ni) electrode for potential application in energy storage devices.</p
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
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
Application of Realtime Robotics platform to execute unstructured industrial tasks involving industrial robots, cobots, and human operators
No full textSmall and medium-sized craft enterprises are still characterized by production process involving human labour to a large extent. The possibility of a safe interaction of the operator in the collaborative working area of the machine, and the development of an easy-to-program robotic cell, would pave the way to the introduction of automation in such an environment. This paper proposes an application of a commercial platform for collision avoidance, based on Dynamic Road-map algorithms, to execute unstructured industrial tasks involving industrial robots, cobots, and human operators at the same time. An example is presented in a pick-and-place and assembling application, in which the components are feed by a conveyor belt with random order and random flow rate. The adopted platform enhances the possibility to exploit in the same robotic cell both industrial robots and human labour, thus allowing a reduction of costs and more precise applications. Moreover, the possibility to calculate at run-time alternative trajectories to avoid obstacles (both human being and other robot in the cell), avoiding to make the robot temporarily inactive, allows to improve the system productivity
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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