An e-pseudovariety is a class of finite regular semigroups closed under the taking of homomorphic images, regular subsemigroups and finite direct products. Chapter One consists of a survey of those results from algebraic semigroup theory, universal algebra and lattice theory which are used in the following two chapters. In Chapter Two, a theory of generalised existence varieties is developed. A generalised existence variety is a class of regular semigroups closed under the taking of homomorphic images, regular subsemigroups, finite direct products and arbitrary powers. Equivalently, a generalised e-variety is the union of a directed family of existence varieties. It is demonstrated that a class of finite regular semigroups is an e-pseudovariety if and only if the class consists only of the finite members of some generalised existence variety. The relationship between certain lattices of e-pseudovarieties and generalised existence varieties is explored and a usefu l complete surjective lattice homomorphism is found. A study of complete congruences on lattices of existence varieties and e-pseudovarieties forms Chapter Three. In particular it is shown that a certain meet congruence, whose description is relatively simple, can be extended to yield a complete congruence on a lattice of e-pseudovarieties of finite regular semigroups. Ultimately, theorems describing the method of construction of all complete congruences of lattices of e-pseudovarieties whose members are finite E-solid or locally inverse regular semigroups are proved.

<p>Broadcast encryption is a fairly new area in cryptology. It was first addressed in 1992, and the research in this area has been large ever since. In short, broadcast encryption is used for efficient and secure broadcasting to an authorized group of users. This group can change dynamically, and in some cases only one-way communication between the sender and receivers is available. An example of this is digital TV transmissions via satellite, in which only the paying customers can decrypt and view the broadcast. </p><p>The purpose of this thesis is to develop a general Java framework for implementation and performance analysis of broadcast encryption algorithms. In addition to the actual framework a few of the most common broadcast encryption algorithms (Complete Subtree, Subset Difference, and the Logical Key Hierarchy scheme) have been implemented in the system. </p><p>This master’s thesis project was defined by and carried out at the Information Theory division at the Department of Electrical Engineering (ISY), Linköping Institute of Technology, during the first half of 2004.</p>

In complex and automated technological processes the effects of a fault can quickly propagate and lead to degradation of process performance or even worse to a catastrophic failure. This means that faults have to be found as quickly as possible and decisions have to be made to stop the propagation of their effects and to minimize process performance degradation. The behavior of the process is affected in different ways by different faults and the fault can be found by ruling out faults for which the expected behavior of the process is not consistent with the observed behavior. In model-based diagnosis, a model describes the expected behavior of the process for the different faults. A device for finding faults is called a diagnosis system. In the diagnosis systems considered here, a number of tests check the consistency of different parts of the model, by using observations of the process. To be able to identify which fault that has occurred, the set of tests that is used must be carefully selected. Furthermore, to reduce the on-line computational cost of running the diagnosis system and to minimize the in general difficult and time-consuming work of tests construction, it is also desirable to use few tests. A two step design procedure for construction of a diagnosis systems is proposed and it provides the means for selecting which tests to use implicitly by selecting which parts of the model that should be tested with each test. Then, the test design for each part can be done with any existing technique for model-based diagnosis. Two different types of design goals concerning the capability of distinguishing faults is proposed. The first goal is to design a sound and complete diagnosis system, i.e., a diagnosis system with the following property. For any observation, the diagnosis system computes exactly the faults that together with the observation are consistent with the model. The second goal is specified by which faults that should be distinguished from other faults, and this is called the desired isolability. Given any of these two design goals, theory and algorithms for selecting a minimum cardinality set of parts of the model are presented. Only parts with redundancy can be used for test construction and a key result is that there exists a sound and complete diagnosis system based on the set of all minimal parts with redundancy in the model. In differentialalgebraic models, it is in general difficult to analytically identify parts with redundancy, because it corresponds to variable elimination or projection. It is formally shown that redundant parts can be found by using a structural approach, i.e., to use only which variables that are included in each equation. In the structural approach, parts with more equations than unknowns are identified with efficient graph-theoretical tools. A key contribution is a new algorithm for finding all minimal parts with redundancy of the model. The efficiency of the algorithm is demonstrated on a truck engine model and compared to the computational complexity of previous algorithms. In conclusion, tools for test selection have been developed. The selection is based on intuitive requirements such as soundness or isolability requirements specified by the diagnosis system designer. This leads to a more straightforward design of diagnosis systems, valuable engineering time can be saved, and the resulting diagnosis systems use minimum number of tests, i.e., the on-line computational complexity of the resulting diagnosis systems become low.

IEEE 802.16e ¡]also known as Mobile WiMAX¡^ is currently the international MAC ¡]medium access control¡^ standard for wireless metropolitan area networks. To enhance the network throughput and extend the coverage of base station, IEEE then defined the 802.16j standard. Clearly, one of the popular applications for WiMAX is the multicast service. On the other hand, the design of power saving technologies is important since mobile stations are often powered by batteries. In this thesis, we study the maximum energy-efficient multicast scheduling ¡]MEMS¡^ problem for an IEEE 802.16j network with transparent mode. Specifically, the base station should determine how to schedule the multicast data in a multicast superframe such that the multicast energy efficiency of network is maximal. We first prove that the MEMS problem is NP-complete. Then on the basis of SMBC-AMC, we propose its variant, called SMBC-relay, to solve this problem. However, in SMBC-relay, the base station may send the same multicast data several times, wasting the scarce bandwidth. Hence we we propose a genetic algorithm-based multicast scheduling algorithm, called GAMS. One of the key features of GAMS is that the base station can control when to terminate the algorithm by stopping the evolution at any time. Simulation results show that GAMS significantly outperforms SMBC-relay in terms of multicast energy efficiency.

In these few years, gradually Internet develops to wideband, multimedia is being used on video or music. In addition, the use of IP Multicast must be based on the deployment of routers, which is too difficult to arrange. Utilities of Application Layer Multicast is in the middle and just between IP Multicast and Unicast.Therefore, in this paper, Application Layer Multicast is still worth to study it. In this paper, is applied effectively build the Application Layer Multicast. Control through the IP Anycast Technique, we can lower the time for host join the Multicast Tree. Every host can join the nearest cluster. We use the hierarchical cluster-based Method in order to serve more hosts. This concept about cluster can substantially decrease control overhead. The Complete Binary Trees lower the cluster leader¡¦s burden, also phased RTT decided effectively the transit sequence. In Summary, associate techniques with methods, to make up the defects from NICE and I-Zigzag.

A new normal form x2 + y2 = c2(1 + x2y2) of elliptic curves was introduced by M. Harold Edwards in 2007 over the field k having characteristic different than 2. This new form has very special and important properties such that addition operation is strongly unified and complete for properly chosen parameter c . In other words, doubling can be done by using the addition formula and any two points on the curve can be added by the addition formula without exception. D. Bernstein and T. Lange added one more parameter d to the normal form to cover a large class of elliptic curves, x2 + y2 = c2(1 + dx2y2) over the same field. In this thesis, an expository overview of the literature on Edwards curves is given. First, the types of Edwards curves over the nonbinary field k are introduced, addition and doubling over the curves are derived and efficient algorithms for addition and doubling are stated with their costs. Finally, known elliptic curves and Edwards curves are compared according to their cryptographic applications. The way to choose the Edwards curve which is most appropriate for cryptographic applications is also explained.

A mixture experiment is an experiment in which the q-ingredients {xi,i=1,...,q} are nonnegative and subject to the simplex restriction sum_{i=1}^q x_i=1 on the (q-1)-dimensional probability simplex S^{q-1}. In this work, we investigate the robust D-optimal designs for mixture experiments with consideration on uncertainties in the Scheffe's linear, quadratic and cubic model without 3-way effects. The D-optimal designs for each of the Scheffe's models are used to find the robust D-optimal designs. With uncertianties on the Scheffe's linear and quadratic models, the optimal convex combination of the two model's D-optimal designs can be proved to be a robust D-optimal design. For the case of the Scheffe's linear and cubic model without 3-way effects, we have some numerical results about the robust D-optimal designs, as well as that for Scheffe's linear, quadratic and cubic model without 3-way effects. Ultimately, we discuss the efficiency of a maxmin type criterion D_r under given the robust D-optimal designs for the Scheffe's linear and quadratic models.

Examinations of stress in relation to adolescent mental health have not often utilized a comprehensive definition of psychological functioning. Recent literature has found support for the importance of examining optimal psychological functioning as the presence of high life satisfaction in addition to low psychopathology (Antamarian, Huebner, Hills, & Valois, 2011; Suldo & Shaffer, 2008). Most research on stress has focused on either major stressful events or chronic environmental stressors; further research is needed on the psychological model of stress, which conceptualizes stress as involving both environmental events and one's cognitive appraisals of the stressor. The current longitudinal study determined how multiple types of stress (accumulation of stressful life events, chronic stressors in social relationships, global perceived stress level) are associated with mental health (i.e., psychopathology and life satisfaction) over a one year period. Additionally, this study explored whether perceptions of social support from various sources (i.e., parents, classmates, teachers) act as a protective factor in the relationship between stress and later mental health outcomes. Data collection for Time 1 occurred in the Fall 2010, and was part of a larger on-going research project involving 500 students from grade 9 - 11. Time 2 data collection occurred during the Fall of 2011 and included 425 of those students, now in grades 10-12. Analyses included multiple regression to examine both the overall contribution of stress on mental health outcomes (life satisfaction, internalizing psychopathology, externalizing psychopathology) as well as the unique contributions of various types of stress. Additional regression analyses explored whether social support from various sources acts as a buffer for students that experience stress from later increases in psychopathology or declines in life satisfaction. Results revealed that the combination of Time 1 mental health variables and all forms of initial stress accounted for the most amount of variance (45%) in Time 2 internalizing problems and the least amount of variance in Time 2 externalizing problems (13%). In all cases, the largest predictor of Time 2 mental health was initial levels of mental health. The only stressor that appeared as a unique predictor of Time 2 mental health was stress in the student-teacher relationship, which accounted for a significant amount of variance in Time 2 externalizing problems. Further regression analyses found that parent and peer support were critical in predicting later mental health (i.e., exerted main effects). These analyses identified trends in the data in which parent and teacher support acted as buffers in the relationships between some forms of stress and later mental health. Implications for school psychologists and future directions for research are discussed.

Many Canadian cities are collectively considering pedestrians, cyclists, public transit, automobiles, and the movement of goods through complete streets, aspiring to enable all people, regardless of age, income, abilities, or lifestyle choices to use streets. Canadian municipal transportation practices are largely based on conventional approaches, where the movement of motor vehicles is a priority. The purpose of this practicum is to identify ways that selected precedents from Canadian and European municipal practices, may inform Canadian municipalities as they seek to incorporate the needs of pedestrians and cyclists – encompassing city planning, transportation engineering, architecture, and urban design considerations. The results of this research exemplify the interdisciplinary involvement required for creating streets as both links and places. Recommendations for Canadian municipalities include aligning municipal design practices with complete streets practices and incorporating interdisciplinary inputs in street design. Ensuring an interdisciplinary university education is recommended for street design professions. / October 2015

We analyze a self-assembly model of flexible DNA tiles and develop a theoretical description of possible assembly products. The model is based on flexible branched DNA junction molecules, which are designed in laboratories and could serve for performing computation. They are also building blocks for make of even more complex molecules or structures. The branched junction molecules are flexible with sticky ends on their arms. They are modeled with "tiles", which are star like graphs, and "tile types", which are functions that give information about the number of sticky ends. A complex is a structure that is obtained by gluing several tiles via their sticky ends. A complex without free sticky ends is called "complete complex". Complete complexes are our main interest. In most experiments, besides the desired end product, a lot of unwanted material also appears in the test tube (or pot). The idea is to use the proper proportions of tiles of different types. The set of vectors that represent these proper proportions is called the "spectrum" of the pot. We classify the types of pots according to the complexes they acan admit, and we can identify the class of each pot from the spectrum and affine spaces. We show that the spectrum is a convex polytope and give an algorithm (and a MAPLE code), which calculates it, and classify the pots in PTIME. In the second part of the dissertation, we approach molecular self-assembly from a graph theoretical point of view. We assign a star-like graph to each tile in a pot, which induces a "pot-graph". A pot-graph is a labeled multigraph corresponding to a given pot type, whose vertices represent tile types. The complexes can be represented by "complex-graphs", and each such graph is mapped homomorphically into a pot-graph. Therefore, the pot-graph can be used to distinguish between pot types according to the structure of the complexes that can be assembled. We begin the third part of the dissertation with a pot containing uniformly distributed DNA junction molecules capable of forming a cyclic graph structure, in which all possible Watson-Crick connections have already been established, and compute the expectation and the variance of the number of self-assembled cycles of any size. We also tested our theoretical results in wet lab experiments performed at Prof. Nadrian C. Seeman's laboratory at New York University. Our main concern was the probability of obtaining cyclic structures. We present the obtained results, which also helped in defining an important parameter for the theoretical model.