830 research outputs found
Motion Planning And Control Of Cooperative Robotic Systems
No full textMOTION PLANNING AND CONTROL OF COOPERATIVE ROBOTIC SYSTEMS Jaydev P. Desai Vijay Kumar James P. Ostrowski This thesis addresses the problem of motion planning for cooperative robotic systems. The problem of motion planning for a robotic system is stated as: Given initial positions and orientations and goal positions and orientations for a collection, C, of robots, in workspace, W, generate a continuous trajectory for C avoiding contact with the obstacles, O i , subject to various dynamical constraints of the system. Because robots are physical systems subject to continuous laws of motion and driven by continuous actuators, we formulate the motion planning problem as an unconstrained variational problem using tools from optimal control and calculus of variations in the first part of the thesis. We develop a general framework for solving motion planning problems involving equality and inequality constraints. In the second part of the thesis, we study planar human manipulation and de..
Test: Internet Indexing Systems vs List of Known URLs: 2001
No full textThis is a compilation of the tests done in 2001 by the author on the then existing search engines. The search engine scene had changed and some of the engines from 1997 were not to be found with some new entries. It was published on the web on the authors home page. As the web pages changed, this was pushed of into the old site and forgotten.
The original HTML pages were converted into PDF using LibreOffice in Aug 2022 and is placed in the Spectrum repository for the record! Who knows some one will find this of interest in the years to come
After 2001, the searching was monopolized, the results were not complete and one passed on to something else. As we know the situation today is such that one search engine is making a fortune and attempts to provide an alternative such as Cliqz could not survive
Acoustic Masking of a Stealthy Outdoor Robot Tracking a Dynamic Target
No full textThis work is motivated by the desire to covertly track mobile targets, either animal or human, in previously unmapped outdoor natural environments using off-road robotic platforms with a non-negligible acoustic signature. The use of robots for stealthy surveillance is not new. Many studies exist but only consider the navigation problem to maintain visual covertness. However, robotic systems also have a significant acoustic footprint from the onboard sensors, motors, computers and cooling systems, and also from the wheels interacting with the terrain during motion. All these can jepordise any visual covertness. In this work, we experimentally explore the concepts of opportunistically utilizing naturally occurring sounds within outdoor environments to mask the motion of a robot, and being visually covert whilst maintaining constant observation of the target. Our experiments in a constrained outdoor built environment demonstrate the effectiveness of the concept by showing a reduced acoustic signature as perceived by a mobile target allowing the robot to covertly navigate to opportunistic vantage points for observation
13th International Symposium on Experimental Robotics
No full textThe International Symposium on Experimental Robotics (ISER) is a series of bi-annual meetings which are organized in a rotating fashion around North America, Europe and Asia/Oceania. The goal of ISER is to provide a forum for research in robotics that focuses on novelty of theoretical contributions validated by experimental results. The meetings are conceived to bring together, in a small group setting, researchers from around the world who are in the forefront of experimental robotics research. This unique reference presents the latest advances across the various fields of robotics, with ideas that are not only conceived conceptually but also explored experimentally. It collects robotics contributions on the current developments and new directions in the field of experimental robotics, which are based on the papers presented at the 13th ISER held held in Québec City, Canada, at the Fairmont Le Château Frontenac, on June 18-21, 2012. This present thirteenth edition of Experimental Robotics edited by Jaydev P. Desai, Gregory Dudek, Oussama Khatib, and Vijay Kumar offers a collection of a broad range of topics in field and human-centered robotics.
A Large Deformation Desai Flow Surface Implementation in Abaqus: Desai Flow Surface Implementation
No full textThis research project aims to implement an elasto-plastic Neo-Hookean Alpha material with a Desai flow surface with hardening and softening in Abaqus via the Continuum Mechanics framework. This is done by first defining the elasto-plastic potato diagram and deriving the corresponding stress tensor definition and dissipation inequality. The elastic deformation gradient is needed in the definition of the stress tensor, which is found by using the Newton-Raphson procedure for the maximization of the dissipation inequality subjected to the plastic flow surface. The Neo-Hookean Alpha elastic material, the Desai plastic flow surface and the definition of the hardening and softening curve are given and are substituted in the stress tensor definition and the corresponding Newton-Raphson procedure, which finishes the derivation of the theory needed to implement this model. This model is implemented in both Abaqus and Python, where the latter is used for rapid prototyping of the model. The methodology of verifying both implementations is presented. The results of the verification of the implementations are given and show that the behaviour of both implementations is as expected and that both implementations correspond to each other; although there are a few small issues. In the end, these issues are discussed, and future recommendations are given to solve them
Duality of Illusion and Reality in Desai\u27s In Custody
No full textIn his article Duality of Illusion and Reality in Desai\u27s In Custody, Narinder K. Sharma analyses Anita Desai\u27s internal confrontation of choices. In the novel, Desai\u27s narration offers various options at every step and the author suggests that it becomes difficult to decide what actually should be done. The attempt is to personalize impersonal time and space thereby brings it into the domain of conflicting choices signifying an existential desire to manifest freedom. Going a step further, it can be deciphered that the individual desires to make an ideal choice to experience authenticity ; however, the desire of making an ideal choice results in the creation of psychic tension. Thus, for Desai, the subject often feels a psychic pull which signifies a lack, a void, or a possibility of something ideal left out or missed. In Sharma\u27s analysis of In Custody the contradiction that splits an individual apart as subjective reflection takes place with relation to making an existential choice
Indická rodina v díle Anity Desai
No full textThe purpose of this diploma thesis is to analyze the parent-child relationship in selected novels by Anita Desai. The novels chosen for the analysis are Cry, the Peacock; Clear Light of Day; Fire on the Mountain; Fasting, Feasting. The aim of the theoretical part is, firstly, to introduce Anita Desai and her style of writing, secondly, to lay the theoretical basis for further analysis of the attachment between children and their parents. In this part the author presents the Attachment theory, behavioural patterns and parenting styles (authoritarian, authoritative, permissive, uninvolved). The theoretical part is concluded by a portrait of Indian society and typical Indian family structure - the environment in which Desai's protagonists live. The practical part consists of thorough analysis of the selected novels. The analysis shows Desai's tendency to portray such parenting styles that instil insecurity in children. The results prove that these approaches to raising a child affect the personality development negatively. It was interesting to find out that gender bias influences not only the life-path and self-concept of the protagonists but also the quality of their relationship with their parents.Smyslem této diplomové práce je analýza vztahu rodič-dítě ve vybraných románech Anity Desai. Romány pro tuto analýzu jsou Cry, the Peacock; Clear Light of Day; Fire on the Mountain; Fasting, Feasting. Cílem teoretické části je zaprvé představit Anitu Desai a její styl tvorby; za druhé položit teoretické základy pro další analýzu vztahu mezi dětmi a jejich rodiči. V této části autorka popisuje teorii konceptu přimknutí, vzorce chování a styly výchovy (autoritářskou, autoritativní, shovívavý, zanedbávající). Teoretickou část uzavírá popis indické společnosti a struktury uvnitř typické indické rodiny - prostředí, v němž žijí postavy Anity Desai. Praktická část se skládá z podrobné analýzy vybraných románů. Tato analýza dokládá sklon Anity Desai k zobrazování takových výchovných stylů, které vyvolávají v dětech pocit nejistoty. Výsledky analýzy dokazují, že tyto postoje k výchově negativně postihují rozvoj osobnosti. Zajímavé bylo zjištění, že diskriminace na základě pohlaví ovlivňuje nejenom životní cestu a sebepojetí protagonistů, ale i povahu vztahu mezi nimi a jejich rodiči.Katedra anglického jazyka a literaturyPedagogická fakultaFaculty of Educatio
Towards the Holy Grail: combining system dynamics and discrete-event simulation in healthcare
No full textThe idea of combining discrete-event simulation and system dynamics has been a topic of debate in theoperations research community for over a decade. Many authors have considered the potential benefits ofsuch an approach from a methodological or practical standpoint. However, despite numerous examples ofmodels with both discrete and continuous parameters in the computer science and engineering literature,nobody in the OR field has yet succeeded in developing a genuinely hybrid approach which truly integratesthe philosophical approach and technical merits of both DES and SD in a single model. In this paperwe consider some of the reasons for this and describe two practical healthcare examples of combinedDES/SD models, which nevertheless fall short of the “holy grail” which has been so widely discussed inthe literature over the past decade
Research in Accounting for Income Taxes
No full textThis paper comprehensively reviews Accounting for Income Taxes (AFIT). The first half provides background and a primer on AFIT. The second half reviews existing studies in detail and offers suggestions for future research. We emphasize the research questions that have been addressed (most of which relate to whether the tax accounts are used to manage earnings, and whether the tax accounts are priced by equity market participants) and highlight areas that have not received much research attention. We close with a call for a theoretical framework, more study of the inconsistencies between research and practice, and improved econometrics.
Characterization of soft tissue cutting for haptic display: experiments and computational models
No full textReal-time medical simulation for robotic surgery planning and surgery training requires realistic yet computationally fast models of the mechanical behavior of soft tissue. This work presents a study to develop such a model to enable fast haptics display in simulation of softtissue cutting. An apparatus was developed and experiments were conducted to generate force-displacement data for cutting of soft tissue such as pig liver. The force-displacement curve of cutting pig liver revealed a characteristic pattern: the overall curve is formed by repeating units consisting of a local deformation segment followed by a local crack-growth segment. The modeling effort reported here focused on characterizing the tissue in the local deformation segment for fast haptic display. The deformation resistance of the tissue was quantified in terms of the local effective modulus (LEM) consistent with experimental forcedisplacement data. An algorithm was developed to determine LEM by solving an inverse problem with iterative finite element models. To enable faster simulation of cutting of a threedimensional (3D) liver specimen of naturally varying thickness, three levels of model order reduction were studied. Additionally, the variation of the LEM with cutting speed was determined. The values of LEM decreased as the cutting speed increased. This thesis also includes the characteristic response of soft tissue to the growth of a cut (cracking) with a scalpel blade. The experimentally measured cut-force versus cut-length data was used to determine the soft tissue’s resistance to fracture (resistance to crack extension) in scalpel cutting. The resistance to fracture of the soft tissue is defined as the amount of mechanical work needed to cause a cut (crack) to extend for a unit length in a soft-tissue sample of unit thickness. The equipment, method, and model are applicable for all soft tissue.Finally, the method of determining the property of the pig liver tissue during cutting was verified. Dual C-arm fluoroscopes were used to obtain the motion of the beads embedded inside the specimen during cutting. The experimentally measured displacement field was compared to the displacement field obtained through finite element model based on the LEM values at each localized area.Ph.D., Mechanical Engineering and Mechanics -- Drexel University, 200
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