No description available.

This thesis investigates the problem of optimal design of binary joint watermarking and scalar quantization (JWSQ) systems that are robust under additive Gaussian attacks. A binary JWSQ system consists of two quantizers with disjoint codebooks. The joint quantization and embedding are performed by choosing the quantizer corresponding to the embedded message. The optimal JWSQ design for both fixed-rate and variable-rate cases was considered in the past, but the solution approaches exhibited high computational complexity. In this thesis, we propose faster binary JWSQ design algorithms for both the fixed-rate and variable-rate scenarios. We achieve the speed up by mapping the corresponding optimization problem to a minimum weight path problem in a certain weighted directed acyclic graph (with a constraint on the length of the path in the fixed-rate case). For this mapping to be possible we discretize the quantizer space and use an approximation for the probability of decoding error. The proposed solution algorithms have $O(LN^3)$ and $O(N^4)$ time complexity in the two cases respectively, where $N$ is the size of discretized source alphabet, and in the fixed-rate scenario $L$ is the number of cells in each quantizer. The effectiveness of the proposed designs is assessed through extensive experiments on a Gaussian source. Our results show that our algorithms are able to achieve performance very close to the prior existing schemes, but only at a small fraction of their running time. / Thesis / Master of Applied Science (MASc)

No description available.

Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2999-01-01

For my thesis I explored the idea of the mask in relation to architecture. For my project I designed an art gallery located in Georgetown Washington DC which is composed of three layers: a structural layer, an environmental casing, and an outer layer. Theoretical parallels are drawn between the outer layer of the gallery and what is commonly referred to as a mask. Additionally, I explored the interaction between the layers of the gallery. The distinguishing characteristics of the building include the tri-facade mask, the unique spaces in between the gallery's layers, the glass system, the mask's ghost effect, and the floor system. / Master of Architecture

Tightening systems are used in several industries, including assembly in the auto- motive industry and installation of computer hardware. Both the company mak- ing the tools and the customers need to know the performance of the tightening system to ensure that the screw joints tighten as desired. This can be done using a test joint system. High demands on safety as well as fast assembly speeds, puts high demands on the test equipment. The problem with the existing test joints is that they are hard to do repeatable tests on. The most common test joints are constructed us- ing mechanic or hydraulic systems. The mechanical systems have problems with wear of screws, changes in lubrication etc., while the hydraulic systems some- times are too slow. This master’s thesis is a study of whether it would be possible to construct a test joint using an electric motor. The electric motor together with a controller should simulate a screw joint so that the tool would perceive it as a real one. All investigation has been performed by system modeling and simulations in MATLAB. Four different control structures have been evaluated: a PID controller, one combined controller which uses feedforward from reference as well as distur- bance, one which is based on the same structure as the second but with an added inner current loop and the last one is an LQ controller. The conclusion is that it is possible to make a test joint using an electric motor and that the LQ controller seems to be the best choice. To prove the result, a few more aspects could be investigated more closely. One is to add a dynamic model of the tool, now only the reference to the tool is used. Another is to implement it on hardware.

published_or_final_version / Business Administration / Master / Master of Business Administration

published_or_final_version / Business Administration / Master / Master of Business Administration

Leading philosophical accounts of joint activity, such as Michael Bratman’s account of ‘shared intentional activity’, take joint activity to be the outcome of two or more agents having a ‘shared intention’, where this is a certain pattern of mutually known prior intentions (plans) that are directed toward a common goal. With Bratman’s account as a foil, I address two lacunas that are relatively unexplored in the philosophical literature. The first lacuna concerns how to make sense of the apparently joint cooperative activities of agents that lack the capacities for planning and “mindreading” that one must have in order to be a party to a shared intention (consider, for example, the social play of young children or the cooperative hunting of non-human primates or social carnivores). The second lacuna concerns how participants (including adult human agents) are able to coordinate their actions “online”—that is, during action execution as a joint activity unfolds—without recourse to plans that specify in advance what they should do (consider the coordination involved when two friends meet and do a “high five”). Chapters 2 and 3 focus on the first lacuna, while chapters 4 and 5 focus on the second. In chapter 2, I focus on why participants must have mutual or common knowledge of each other’s intentions and beliefs in order to have a shared intention: Why must these attitudes be “out in the open”? I argue that, if participants lack the concept of belief, then one of the two main motivations for the common knowledge requirement—to filter out certain cases that intuitively aren’t cases of genuine joint activity—actually dissipates. Furthermore, a kind of “openness” that only requires of participants that they have the concept of goal but not that of belief can satisfy the other main motivation, to make sense of the idea that joint activities are non-accidentally coordinated. In chapter 3, I offer an account of a kind of joint activity in which agents such as young children and some non-human primates could participate, given what we know about their socio-cognitive capacities. In chapter 4, I argue that ‘shared intention’-accounts are unable to say much about spontaneous or skilful joint action because of the following widely accepted constraint on what one can intend: while an agent might intend—in the sense of commit to a plan—that “we” do something together, an agent cannot intend to perform “our” joint action. I reject this constraint and argue that some joint actions (such as a joint manoeuvre performed by two figure skaters) are joint in virtue of each participant having what I call ‘socially extended intention-in-action’ that overlap. In chapter 5, I review empirical work on subpersonal enabling mechanisms for the coordination of joint action. The review provides clues to what it is that enables participants to successfully coordinate their actions in the absence of plan-like intentions or beyond what such intentions specify. While what I address are lacunas rather than problems, an upshot of this thesis is that leading philosophical accounts of joint activity may have less explanatory scope than one might otherwise be led to believe. The accounts of joint activity and joint action that are presented in this thesis are arguably applicable to many of the joint activities and joint actions of adult human beings. The account also helps us avoid the false dichotomy between a very robust form of joint activity and a mere concatenation of purely individualistic actions—a dichotomy that accounts such as Bratman’s arguably invite us to adopt.

Thesis (M.Sc.(Occupational Therapy))--University of the Witwatersrand, Faculty of Health Sciences, 2014.