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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Vehicle tracking using scale invariant features

Wang, Jue, Computer Science & Engineering, Faculty of Engineering, UNSW January 2008 (has links)
Object tracking is an active research topic in computer vision and has appli- cation in several areas, such as event detection and robotics. Vehicle tracking is used in Intelligent Transport System (ITS) and surveillance systems. Its re- liability is critical to the overall performance of these systems. Feature-based methods that are used to represent distinctive content in visual frames are one approach to vehicle tracking. Existing feature-based tracking systems can only track vehicles under ideal conditions. They have difficulties when used under a variety of conditions, for example, during both the day and night. They are highly dependent on stable local features that can be tracked for a long time period. These local features are easily lost because of their local property and image noise caused by factors such as, headlight reflections and sun glare. This thesis presents a new approach, addressing the reliability issues mentioned above, tracking whole feature groups composed of feature points extracted with the Scale Invariant Feature Transform (SIFT) algorithm. A feature group in- cludes several features that share a similar property over a time period and can be tracked to the next frame by tracking individual feature points inside it. It is lost only when all of the features in it are lost in the next frame. We cre- ate these feature groups by clustering individual feature points using distance, velocity and acceleration information between two consecutive frames. These feature groups are then hierarchically clustered by their inter-group distance, velocity and acceleration information. Experimental results show that the pro- posed vehicle tracking system can track vehicles with the average accuracy of over 95%, even when the vehicles have complex motions in noisy scenes. It gen- erally works well even in difficult environments, such as for rainy days, windy days, and at night. We are surprised to find that our tracking system locates and tracks motor bikes and pedestrians. This could open up wider opportunities and further investigation and experiments are required to confirm the tracking performance for these objects. Further work is also required to track more com- plex motions, such as rotation and articulated objects with different motions on different parts.
12

An Analysis of the Progress in Automation of Manned Space-craft Test and Checkout

Malone, John E. 01 January 1975 (has links) (PDF)
Manned Spacecraft Programs are the largest research and development tasks ever undertaken by the government or by private industry in the United States. Under the direction of the National Aeronautic and Space Administration (NASA) these programs have advanced from Project Mercury in the early 1960's through Gemini, Apollo, including Moon Landing, and Skylab Programs to the present day Space Shuttle Program. With the development of each new program, there comes a growing awareness of the ever increasing complexity of tasks relating to integrated preflight test and checkout. Data rates have grown from one (1) pulse amplitude modulated/frequency modulated (PAM/FM) link with just over a hundred (100) measurements to multiple pulse code modulated (PCM) links with many thousands of measurements and bit rates up to fifty (50) megabits per second (MBPS). A unique requirement of Manned Spacecraft Programs in the "Man Rating" concept. Man rating requires that every failure and test anomaly be analyzed, understood and/or corrected prior to flight. This further complicates an already complex test and checkout program. Exploitation of the potentials of automation was and is the only recourse for present day and future programs. Such automation should be as automatic as possible but must have a man-in-the-loop capability to assure that the test engineer has positive control at all times. This paper analyzes the progress in automation in round test and checkout from Project Mercury days with a simplified prototype technique for Space Shuttle.
13

Liability risk management for activities related to the launch of space objects : today's environment and tomorrow's prospects

Kayser, Valérie. January 2000 (has links)
Launch activities are increasingly performed by private entities and launch participants deal with a complex legal environment. The Space Treaties provide a framework placing liability for non-governmental activities on the launching State and the duty to authorize and supervise them on the appropriate State. Launch participants are subject to specific regulation in certain States or are under institutional State control in others. They also have to comply with general domestic law of liability. Limited insurance availability led to the development of contractual risk allocation techniques, the inter-participants waivers of liability and claims, inspired by NASA practice. / This thesis offers a contribution with the synthesis of information, so far scattered, on today's legal environment, providing an overview of the norms at play in this field to allow the grasp of their relative weight and interactions in the assessment of liability risk attached to launch activities. / This synthesis reveals a legal framework presently lacking the predictability necessary for an efficient liability risk management: (1) inter-participants waivers of liability suffer the weaknesses of all limitation of liability clauses; they also lack uniformity and implementation rigor; (2) the Space Treaties contain ambiguous terms preventing predictable determination of the State liable for damage and the State obliged to authorize and supervise launch activities, and do not reflect the de facto primary liability of launch operators. / This thesis offers a contribution to the advancement of legal work on these problems by suggesting new approaches emphasizing the need for: (1) harmonization of inter-participants waivers of liability to improve their consistency and validity and ensure identical flow-down by all participants; (2) improvements of the Outer Space Treaty, Liability Convention and Registration Convention for their implementation to non-governmental launch activities. / Although the launch community is small and the need for lawmaking is not as compelling as in fields such as aviation. Nevertheless, tailored adjustments to the present legal framework are required and proposed in this thesis through model clauses and an international instrument, both of which are submitted for further thinking and contribution by those sharing the opinion that creative lawmaking is now necessary to prepare for tomorrow's endeavors.
14

Liability risk management for activities related to the launch of space objects : today's environment and tomorrow's prospects

Kayser, Valérie January 2000 (has links)
No description available.
15

Evaluation and automation of space habitat interior layouts

Simon, Matthew 27 May 2016 (has links)
Future human exploration missions beyond Earth vicinity will be demanding, requiring highly efficient, mass-constrained systems to reduce overall mission costs and complexity. Additionally, long duration transits in space and lack of Earth abort opportunities will increase the physiological and psychological needs of the crew, which will require larger, more capable systems to ensure astronaut well-being. As a result, the objective of habitat design for these missions is to minimize mass and vehicle size while providing adequate space for all necessary equipment and a functional layout for crew health and productivity. Unfortunately, a literature review of methods for evaluating the performance of habitat interior layout designs (including human-in-the-loop mockup tests, in-depth computer-aided design evaluations, and subjective design evaluation studies) found that they are not currently compatible with the conceptual phase of design or optimization because of the qualitative nature of the comparisons and the significant time required to generate and evaluate each layout. Failure to consider interior layout design during conceptual design can lead to increased mass, compromised functionality, and increased risk to crew; particularly for the mass, cost, and volume-constrained long duration human missions to cislunar space and Mars currently being planned by NASA. A comprehensive and timely quantitative method to measure the effectiveness of interior layouts and track the complex, conflicting habitat design objectives earlier in the design process is desired. A new, structured method and modeling framework to quickly measure the effectiveness of habitat interior designs is presented. This method allows for comparison of layouts at conceptual design and advances research in the previously unavailable capability to automate the generation of habitat interiors. This evaluation method features the development of a comprehensive list of quantifiable habitat layout evaluation criteria, the development of automatic methods to measure these criteria from a geometry model and designer inputs, and the application of systems engineering tools and numerical methods to construct a multi-objective value function measuring the overall habitat layout performance. In particular, this method featured the separation of subjective designer preferences and quantitative evaluation criteria measurements to speed layout evaluations and enable automation of interior layout design subject to a set of designer preferences. This method was implemented through the construction of a software tool utilizing geometry modeling coupled with collision detection techniques to identify favorable layouts subject to multiple constraints and objectives (e.g., minimize mass, maximize contiguous habitable volume, maximize task performance efficiency). Notional cis-lunar habitat layouts were evaluated to demonstrate the effectiveness of the method. Furthermore, stochastic optimization was applied to understand and address difficulties with automated layout design, particularly constraint implementation and convergence behavior. Findings from these investigations and implications for future research are discussed.
16

La nationalité comme base de juridiction sur les engins spatiaux /

Samuelli, Antoine. January 1967 (has links)
No description available.
17

Responsibility in international law for commercial space activities

Gouesse, Emmanuel. January 2000 (has links)
Space activities are increasingly undertaken by private companies. Space law, however, was mainly developed in the beginning of the space age, at a time where space activities were predominantly state activities. The rules that developed were thus focusing on the duties of states and concerned private entities only through the intermediary of states. / This thesis explores the applicable principles of space law and of the international law of responsibility. Taking into account the recent practice of private companies engaged in space business, the work also focuses both on its impact on the responsibility and liability regime as well as on the legal efficiency of the links between private entities and states. / In conclusion, the thesis makes several recommendations to improve the responsibility regime for space activities.
18

La nationalité comme base de juridiction sur les engins spatiaux /

Samuelli, Antoine. January 1967 (has links)
No description available.
19

Nationality of spacecraft and liability for space activities

Galicki, Zdzislaw W. January 1969 (has links)
No description available.
20

Commercial human space flight in the United States : federal licensing and tort liability

Mineiro, Michael C. January 2008 (has links)
In the early 21st century, the private commercial space transportation industry demonstrated that commercial human space flight is both technologically and economically feasible. In 2004, the United States Congress responded by passing legislation authorizing the Department of Transportation to license and regulates commercial human space flight. / This thesis examines and assesses the U.S. commercial human space flight vehicle licensing and regulatory law. Tort liability is inextricably linked to the success of the commercial human space flight industry and to that end this thesis provides an analysis of U.S. tort liability law in the event of a commercial human space flight vehicle accident.

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