The general aim of the study was to determine the effect of feedback derived from task observations on lower-level employees’ empowerment, motivation and performance in a selected steel production company. Feedback plays an important role in empowering and motivating employees to improve performance. Previous research indicates that relationships exist between feedback and empowerment, motivation and performance. However, past research was confined to particular context(s), and the effect of feedback on lower-level employees has received little research attention. It was identified that feedback derived from task observations could potentially become a tool to enable lower-level employees to be empowered to perform to the best of their abilities. The research design used is a quantitative non-experimental cross-sectional approach, where questionnaires were used to collect data. The targeted population was all 500 lower-level skilled workers at one business unit of a selected steel production company. Only 308 lower-level employees were available and willing to participate. The findings of the study indicate that there is a statistically significant positive relationship between feedback as derived from task observations and employee empowerment, motivation and performance. The positive relationship found between feedback and empowerment indicates that feedback derived from task observations can be used as a critical component in empowering and motivating lower-level employees to improve performance. / MBA, North-West University, Potchefstroom Campus, 2015

<p>U tezi je analiziran problem kontrole pristupa u Smart Grid sistemima. Formalno je specificiran model kontrole pristupa za Smart Grid koji je zasnovan na unapređenju i proširenju RBAC modela i koji je usklađen sa aktuelnim zahtevima u elektroenergetskoj industriji. Postavljena je softverska arhitektura predloženog modela kontrole pristupa, čija je prototipska implementacija zatim integrisana u simuliranom Smart Grid okruženju.</p> / <p>This thesis discusses the challenges related to access control in Smart<br />Grid systems. A formal model for access control in the Smart Grid is<br />specified, extending the role-based access control (RBAC) model to be<br />in accordance with the existing security requirement in the power industry.<br />Based on the proposed access control model, software architecture was<br />developed and its prototype implementation is integrated in a Smart Grid<br />simulated environment.</p>

Privacy concerns have always been present in every society. The introduction of information technology information has enabled a reduction in the cost of gathering information, management of that information and the permitted that same information to become increasingly portable. Coupled with these reductions of cost has been an increase in the demand for information as well as the concern that privacy expectations be respected and enforced through security systems that safeguard access to private-type data. Security systems enforce privacy expectations. Unfortunately there is no consensus on a definition of privacy making the specification of security often over broad and resulting in the loss of critical functionality in the systems produced. This research expands the understanding of privacy by proposing a replicable type-based taxonomy of privacy that is grounded in philosophy and law. This type-based system is applied to a Role Based Access Control System to specify and control access to data in a in a hospital setting as a proof of concept.

This thesis study proposes a method for organizations to perform business process modeling in a decentralized and concurrent manner. The Plural method is based on the idea that organizations&rsquo / processes can be modeled by individuals actually performing the processes. Instead of having a central and devoted group of people to understand, analyze, model and improve processes, individuals are held responsible to model and improve their own processes concurrently. These individual models are then integrated to form organization&rsquo / s process network. The method guides the application of this approach in organizations with the activities to be followed and the artifacts to be produced. To apply the method, the study also introduces a notation and a prototype toolset. A multiple-case study involving two cases is conducted in order to evaluate the applicability of the method for decentralized process modeling and validate the expected benefits.

<p>In the area of computer network security, standardization work has been conducted for several years. However, the sub area of access control and authorization has so far been left out of major standardizing. </p><p>This thesis explores the ongoing standardization for access control and authorization. In addition, areas and techniques supporting access control are investigated. Access control in its basic forms is described to point out the building blocks that always have to be considered when an access policy is formulated. For readers previously unfamiliar with network security a number of basic concepts are presented. An overview of access control in public networks introduces new conditions and points out standards related to access control. None of the found standards fulfills all of our requirements at current date. The overview includes a comparison between competing products, which meet most of the stated conditions. </p><p>In parallel with this report a prototype was developed. The purpose of the prototype was to depict how access control could be administered and to show the critical steps in formulating an access policy.</p>

Η διπλωματική εργασία ασχολείται με την ανάγκη για έναν προηγμένο μηχανισμό ασφάλειας που θα παρέχει προστασία πληροφοριών από τους μη εξουσιοδοτημένους χρήστες. Τα περισσότερα συστήματα σε εταιρικό και βιομηχανικό επίπεδο χρησιμοποιούν την απλή εξουσιοδότηση (simple authorization) ή all-or-nothing όπου έχουμε παραχώρηση πρόσβασης στους πόρους του συστήματος εάν ο χρήστης είναι εξουσιοδοτημένος ή εάν δεν είναι άρνηση πρόβλεψης χωρίς να έχει προβλεφθεί κάποια ενδιάμεση λύση. Στην περίπτωση του ελέγχου πρόσβασης για υπηρεσίες Ιστού (web services) –που είναι εφαρμογές που παρέχονται μέσω Διαδικτύου όπως φαίνεται και από το όνομά τους- δεν είναι ικανοποιητική η παραχώρηση πρόσβασης σε ολόκληρη την υπηρεσία Ιστού δηλαδή η πρόσβαση στο υψηλότερο επίπεδο (coarse-grained access control) αλλά απαιτείται και η πρόσβαση σε κάποια ή κάποιες από τις μεθόδους την υπηρεσίας Ιστού δηλαδή η διαβαθμισμένη πρόσβαση (fine-grained access control). Η πολιτική ελέγχου πρόσβασης που χρησιμοποιήσαμε είναι ο έλεγχος πρόσβασης βασισμένος σε ρόλους (Role-based Access Control) όπου οι χρήστες αποκτούν πρόσβαση στους προστατευόμενους πόρους (μια ολόκληρη υπηρεσία Ιστού ή μέθοδο) συνδεόμενοι με ρόλους με τις κατάλληλες άδειες πρόσβασης δηλαδή μόνο εξουσιοδοτημένοι χρήστες έχουν πρόσβαση στους προστατευόμενους πόρους. Τέλος υποθέσαμε μία βιομηχανική υποδομή που παρέχει σε πελάτες πρόσβαση μέσω ενός OPC XML-DA server όπου το OPC είναι ένα σύνολο από ανοικτά πρότυπα που παρέχουν δια-λειτουργικότητα (interoperability) και συνδεσιμότητα (connectivity) μεταξύ βιομηχανικού αυτοματισμού και επιχειρησιακών συστημάτων. / -

Access control is used to provide regulated access to resources by principals. It is an important and foundational aspect of information security. Role-Based Access Control (RBAC) is a popular and widely-used access control model, that, as prior work argues, is ideally suited for enterprise settings. In this dissertation, we address two problems in the context of RBAC. One is the User Authorization Query (UAQ) problem, which relates to sessions that a user creates to exercise permissions. UAQ's objective is the identification of a set of roles that a user needs to activate such that the session is authorized to all permissions that the user wants to exercise in that session. The roles that are activated must respect a set of Separation of Duty constraints. Such constraints restrict the roles that can be activated together in a session. UAQ is known to be intractable (NP-hard). In this dissertation, we give a precise formulation of UAQ as a joint-optimization problem, and analyze it. We examine the manner in which each input parameter contributes to its intractability. We then propose an approach to mitigate its intractability based on our observation that a corresponding decision version of the problem is in NP. We efficiently reduce UAQ to Boolean satisfiability in conjunctive normal form (CNF-SAT), a well-known NP-complete problem for which solvers exist that are efficient for large classes of instances. We also present results for UAQ posed as an approximation problem; our results suggest that efficient approximation is not promising for UAQ. We discuss an open-source implementation of our approach and a corresponding empirical assessment that we have conducted. The other problem we consider in this dissertation regards an efficient data structure for distributed access enforcement. Access enforcement is the process of validating an access request to a resource. Distributed access enforcement has become important with the proliferation of data, which requires access control systems to scale to tens of thousands of resources and permissions. Prior work has shown the effectiveness of a data structure called the Cascade Bloom Filter (CBF) for this problem. In this dissertation, we study the construction of instances of the CBF. We formulate the problem of finding an optimal instance of a CBF, where optimality refers to the number of false positives incurred and the number of hash functions used. We prove that this problem is NP-hard, and a meaningful decision version is in NP. We then propose an approach to mitigate the intractability of the problem by reducing it to CNF-SAT, that allows us to use a SAT solver for instances that arise in practice. We discuss an open-source implementation of our approach and an empirical assessment based on it.

Role-based modeling has been proposed in 1977 by Charles W. Bachman, as a means to model complex and dynamic domains, because roles are able to capture both context-dependent and collaborative behavior of objects. Consequently, they were introduced in various fields of research ranging from data modeling via conceptual modeling through to programming languages. More importantly, because current software systems are characterized by increased complexity and context-dependence, there is a strong demand for new concepts beyond object-oriented design. Although mainstream modeling languages, i.e., Entity-Relationship Model, Unified Modeling Language, are good at capturing a system's structure, they lack ways to model the system's behavior, as it dynamically emerges through collaborating objects. In turn, roles are a natural concept capturing the behavior of participants in a collaboration. Moreover, roles permit the specification of interactions independent from the interacting objects. Similarly, more recent approaches use roles to capture context-dependent properties of objects. The notion of roles can help to tame the increased complexity and context-dependence. Despite all that, these years of research had almost no influence on current software development practice. To make things worse, until now there is no common understanding of roles in the research community and no approach fully incorporates both the context-dependent and the relational nature of roles. In this thesis, I will devise a formal model for a family of role-based modeling languages to capture the various notions of roles. Together with a software product line of Role Modeling Editors, this, in turn, enables the generation of a role-based language family for Role-based Software Infrastructures (RoSI).

Present-day software systems have to fulfill an increasing number of requirements rendering them more and more complex. Many systems need to anticipate changing contexts (self-adaptive systems) or need to adapt to changing business rules or requirements (self-optimizing systems). The challenge of 21th century software development will be to cope with these aspects. We believe that the role concept offers a simple way to adapt object-oriented programs to their changing contexts. In a role-based language, an object plays multiple roles during its lifetime. If the contexts are represented as first-class entities, they provide dynamic views to the object-oriented program, and if the context changes, the dynamic views can be switched easily, and the software system adapts automatically. However, the concepts of roles and dynamic contexts have been discussed for a long time in many areas of computer science. So far, their implementation in an existing object-oriented language requires a specific runtime environment. Also, classical object-oriented languages and their runtime systems are not able to cope with essential role-specific features, such as true delegation or dynamic binding of roles. As a solution, this work presents a simple implementation pattern for role-based objects that does not require a specific runtime system, SCROLL (SCala ROles Language). The implementation pattern is demonstrated on the basis of the Scala language. As technical support from Scala, the pattern requires dynamic mixins, compiler-translated function calls, and implicit conversions. The implementation details of the pattern are hidden in a Scala library and therefore transparent to Scala programmers. The SCROLL library supports roles embedded in structured contexts, so-called compartments. We show that they are specific, hierarchic runtime views, which enables hierarchic view-based programming for free in Scala. We also discuss how to apply the implementation pattern of SCROLL for other languages, in particular for behavioral modeling languages in MDSD. This discussion shows that the SCROLL pattern can be embedded into the generated code, so that it still is hidden to the developer, but does not require a specific runtime system. Using the pattern in model-driven code generation enables dynamic views for all kinds of modeling languages. And therefore, this paper shows a way how to realize dynamic views for all modeling languages in MDSD.

In this new digital age, efficiency, quality and competition are all increasing rapidly as companies leverage the Industrial Internet of Things (IIoT). However, while industrial innovation moves at a faster and faster pace, educational institutions have lagged in the development of the curriculum and environment needed to support further development of the IIoT. To fully realize the potential of the IIoT in the manufacturing sector educational institutions must support the technological training and education rigor demanded to instill the skills and thought leadership to move the industry forward. The purpose of this research is to provide an IIoT core system in an educational factory environment. This system will assist in teaching basic principles of IIoT in the factory while simultaneously allowing for students to envision the manufacturing journey of any facility by implementing principles of IIoT. This will be accomplished by providing all the following capabilities together in a single data system: unified connectivity, role-based data display, real-time issue identification, data analytics, and augmented reality.