Consider a feedforward network of single-server stations populated by multiple job types. Each job requires the completion of a number of tasks whose order of execution is determined by a set of deterministic precedence constraints. The precedence requirements allow some tasks to be done in parallel (in which case tasks would "fork") and require that others be processed sequentially (where tasks may "join"). Jobs of a. given type share the same precedence constraints, interarrival time distributions, and service time distributions, but these characteristics may vary across different job types. We show that the heavy traffic limit of certain processes associated with heterogeneous fork-join networks can be expressed as a semimartingale reflected Brownian motion with polyhedral state space. The polyhedral region typically has many more faces than its dimension, and the description of the state space becomes quite complicated in this setting. One can interpret the proliferation of additional faces in heterogeneous fork-join networks as (i) articulations of the fork and join constraints, and (ii) results of the disordering effects that occur when jobs fork and join in their sojourns through the network.

No description available.

Understand the behavior of queueing networks in heavy tra c is very important due to its importance in evaluating the network performance in related applications. However, in many cases, the stationary distributions of such networks are intractable. Based on di usion limits of queueing networks, we can use Re ected Brownian Motion (RBM) processes as reasonable approximations. As such, we are interested in obtaining the stationary distribution of RBM. Unfortunately, these distributions are also in most cases intractable. However, the tail behavior (large deviations) of RBM may give insight into the stationary distribution. Assuming that a large deviations principle holds, we need only solve the corresponding variational problem to obtain the rate function. Our research is mainly focused on how to solve variational problems in the case of rotationally symmetric (RS) data. The contribution of this dissertation primarily consists of three parts. In the rst part we give out the speci c stability condition for the RBM in the octant in the RS vi case. Although the general stability conditions for RBM in the octant has been derived previously, we simplify these conditions for the case we consider. In the second part we prove that there are only two types of possible solutions for the variational problem. In the last part, we provide a simple computational method. Also we give an example under which a spiral path is the optimal solution. / text

This dissertation explores the role of social context in advertisement responses, specifically focusing on how the interaction between the social identities to which a person ascribes influence the manner in which they respond to advertisements. The first essay explores how social context and social identity influence perceptions of an advertisement's authenticity. A multi-method, four-study inquiry into perceptions of advertising authenticity combining depth interview, survey, and experimental techniques finds consumer perceptions of authenticity play a key role in attitudes toward advertisements. Findings show consumers naturally assess ads in terms of authenticity and that these perceptions are entwined with self-referencing. In addition, other-referencing is shown to also be linked to authenticity perceptions and ad liking. Finally, a boundary condition on the relationship between authenticity perceptions, self-referencing, and ad liking is discussed, where consumers' reflected appraisals of how they think others will view an advertisement moderates the relationship between self-referencing and attitude towards the ad.The second essay explores, using three experiments, the relationship between reflected appraisals, self-referencing, and ad liking in more detail. Specifically, this essay determines the conditions under which negative reflected appraisals do and not decrease attitude towards the ad. First, this essay shows that when identity and self-referencing are primed, consumers resist negative appraisals about an identity congruent advertisement such that negative appraisals do not decrease ad attitudes. This effect however, does not hold when the target market for an advertisement is external to the social identity and negative appraisals are attributed to out-group members. Here, consumers pay attention to the negative appraisals and decease their attitude toward the ad. This effect, referred to as the dirty laundry effect, occurs because consumers conceptualize identity congruent advertisements as a type of self-presentation. Thus, instead of engaging in defensive behaviors in the face of negative appraisals, consumers become concerned with how they think other people will view them based on the content of the advertisement.

The surface of the weld pool contains information that can be exploited to emulate a skilled human welder to better understand and control the welding process. Of the existing techniques, the method that uses the pool's specular nature to an advantage and which is relatively more cost effective, and suitable for welding environment is the one that utilizes reflected images to reconstruct 3D weld pool surface by using structured light and image processing techniques. In this thesis, an improvement has been made to the existing method by changing welding direction to obtain a denser reflected dot-matrix pattern allowing more accurate surface measurement. Then, the reflected images, obtained by capturing the reflection of a structured laser dot-matrix pattern from the pool surface through a high-speed camera with a narrow band-pass filter, are processed by a newly proposed algorithm to find the position of each reflected dot relative to its actual projection dot. This is a complicated process owing to the increased density of dots and noise induced due to the harsh environment. The obtained correspondence map may later be used by a surface reconstruction algorithm to derive the three-dimensional pool surface based on the reflection law.

As organizations grow and expand past their operational headquarters, individual branches may reflect a different identity than that of the headquarters. The question then is, "Is senior management able to transcend geographical boundaries and communicate the identity that has shaped their strategy for the organization?" The purpose of this study is to examine the impact of geographical expansion on the reflected perceptions of internal stakeholders related to the organization's intended identity as defined by senior management. Through this study, four themes emerged from the data. The themes included a reliance on reputation, a sense of belonging, peer influence, and communication congruence. Based on this data, the study provides a marketing of identity process to assist organizations in communicating their identity throughout the organization and across geographic locations.

Abstract [en] Background. Penetration testing is a good technique for finding web vulnerabilities. Vulnerability scanners are often used to aid with security testing. The increased scope is becoming more difficult for scanners to handle in a reasonable amount of time. The problem with vulnerability scanners is that they rely on fuzzing to find vulnerabilities. A problem with fuzzing is that: it generates a lot of network traffic; scans can be excruciatingly slow; limited vulnerability detection if the output string is modified due to filtering or sanitization. Objectives. This thesis aims to investigate if an XSS vulnerability scanner can be made more scalable than the current state-of-the-art. The idea is to examine how reflected parameters can be detected, and if a different methodology can be applied to improve the detection of XSS vulnerabilities. The proposed vulnerability scanner is named Mantis. Methods. The research methods used in this thesis are literature review and experiment. In the literature review, we collected information about the investigated problem to help us analyze the identified research gaps. The experiment evaluated the proposed vulnerability scanner with the current state-of-the-art using the dataset, OWASP benchmark. Results. The result shows that reflected parameters can be reliably detected using approximate string matching. Using the parameter mapping, it was possible to detect reflected XSS vulnerabilities to a great extent. Mantis had an average scan time of 78 seconds, OWASP ZAP 95 seconds and Arachni 17 minutes. The dataset had a total of 246 XSS vulnerabilities. Mantis detected the most at 213 vulnerabilities, Arachni detected 183, and OWASP ZAP 137. None of the scanners had any false positives. Conclusions. Mantis has proven to be an efficient vulnerability scanner for detecting XSS vulnerabilities. Focusing on the set of characters that may lead to the exploitation of XSS has proven to be a great alternative to fuzzing. More testing of Mantis is needed to determine the usability of the vulnerability scanner in a real-world scenario. We believe the scanner has the potential to be a great asset for penetration testers in their work.

Through the investigation of indirect light, reflected color, and geometric construction, and by the awareness and understanding of what allows for experiences that engage the human emotion, this thesis offers a project which has the power and presence to move the soul. / Master of Architecture

Cette thèse traite des équations différentielles stochastiques rétrogrades réfléchies du second ordre dans une filtration générale . Nous avons traité tout d'abord la réflexion à une barrière inférieure puis nous avons étendu le résultat dans le cas d'une barrière supérieure. Notre contribution consiste à démontrer l'existence et l'unicité de la solution de ces équations dans le cadre d'une filtration générale sous des hypothèses faibles. Nous remplaçons la régularité uniforme par la régularité de type Borel. Le principe de programmation dynamique pour le problème de contrôle stochastique robuste est donc démontré sous les hypothèses faibles c'est à dire sans régularité sur le générateur, la condition terminal et la barrière. Dans le cadre des Équations Différentielles Stochastiques Rétrogrades (EDSRs ) standard, les problèmes de réflexions à barrières inférieures et supérieures sont symétriques. Par contre dans le cadre des EDSRs de second ordre, cette symétrie n'est plus valable à cause des la non linéarité de l'espérance sous laquelle est définie notre problème de contrôle stochastique robuste non dominé. Ensuite nous un schéma d'approximation numérique d'une classe d'EDSR de second ordre réfléchies. En particulier nous montrons la convergence de schéma et nous testons numériquement les résultats obtenus. / This thesis deals with the second-order reflected backward stochastic differential equations (2RBSDEs) in general filtration. In the first part , we consider the reflection with a lower obstacle and then extended the result in the case of an upper obstacle . Our main contribution consists in demonstrating the existence and the uniqueness of the solution of these equations defined in the general filtration under weak assumptions. We replace the uniform regularity by the Borel regularity(through analytic measurability). The dynamic programming principle for the robust stochastic control problem is thus demonstrated under weak assumptions, that is to say without regularity on the generator, the terminal condition and the obstacle. In the standard Backward Stochastic Differential Equations (BSDEs) framework, there is a symmetry between lower and upper obstacles reflection problem. On the contrary, in the context of second order BSDEs, this symmetry is no longer satisfy because of the nonlinearity of the expectation under which our robust stochastic non-dominated stochastic control problem is defined. In the second part , we get a numerical approximation scheme of a class of second-order reflected BSDEs. In particular we show the convergence of our scheme and we test numerically the results.

Recent events including deliberate terrorist attacks and accidental explosions have highlighted the need for comprehensive research in the area of structural response to blast loading. Research in this area has recently received significant attention by the civil engineering community. Reinforced Concrete (RC) water reservoir tanks are an integral part of the critical infrastructure network of urban centers and are vulnerable to blast loading. However, there is a lack of research and knowledge on the performance of RC reservoir walls under blast loading. The objective of this research study is to experimentally investigate the performance of reinforced concrete reservoir walls subjected to blast loading and to analyze the structural response. This study provides experimental test data on the performance of reinforced concrete reservoir walls under blast loading and complementary analytical predictions using the Singe-Degree-Of-Freedom (SDOF) analysis method. The reservoir walls in this study were designed according to the water volume capacity using the Portland Cement Association (PCA 1993) methodology. The design was validated using software SAP 2000. The experimental program involved the construction and simulated blast testing of two RC reservoir wall specimens with different support conditions: (1) two opposite lateral edges fixed, bottom edge pinned and top edge free; and (2) two opposite lateral edges fixed, and bottom and top edges free. The first boundary condition was intended to promote two-way bending action, while the second was dominated by one-way bending. The two specimens were each subjected to a total of six consecutive incrementally increasing blast tests. The experimental program was conducted in the shock tube testing facility that is housed in the University of Ottawa. Wall displacements, reinforcement strains, and reflected pressures and impulses were measured during testing. Analytical calculations were conducted using the equivalent SDOF method to simulate the dynamic response of the RC reservoir wall specimens under different blast loadings. Published tables, charts and coefficients contained in Biggs (1964) and UFC 3-340-02 (2008) were adopted in the equivalent SDOF calculations. The analytical results were compared against the ii experimental data. The SDOF method predicted smaller displacements than those recorded during testing. The approximate nature of the parameters and tables used in the equivalent SDOF calculations contributed to the discrepancy between the analytical and experimental results. Furthermore, assumptions regarding the support conditions and neglecting residual damage from previous blast tests contributed to the underestimation of the displacements.