The purpose of the research was to investigate the way in which employees in two departments of a Greek industrial company resolved conflict situations encountered in the context of their department. The premises are that (a) the positive effects of conflict for the organization are related to the way in which it is resolved; (b) the investigation of the phenomenon of conflict resolution necessitates the examination of employees' conflict handling behaviour during a conflict episode, as well as of their representation of the particular episode; (c) the bureaucratic culture of the organization and the wider social culture determine the conditions within which employees represent and deal with conflict situations. The research used a single case design to develop new ways to model the conflict resolution process. The use of open-ended interviews constituted the methods of data collection. Employees from two departments (Research/Design and Supplies) of the organization were selected. The analysis of data in the first part of the thesis led to the development of a net model, indicating patterns of conflict handling behaviour during any conflict episode; the generic structure of the net model, which was found to be common to both departments, was discussed in the light of Greek culture, as well as of the bureaucratic practices of that particular organization. On the basis of this analysis, a further analysis was made of the data relating to those nodes of the net model where employees were found to be involved in a decision making process. The methodology selected enabled the representation of the process of the conflict management problem by organizational members. The basic assumption incorporated within this methodology is that the conflict management problem can be represented in more than one way. The identification, via employees' discourse, of the way in which conflict situations are conceptualized in the context of the two departments, indicated how this representation relates to the wider social and organizational nexus within which it is embedded. The contribution of this study lies in identifying the conflict resolution structures and processes within two departments of the organization studied and, to a certain extent, the wider organization, while offering an insight into how this organization shapes the way in which conflict situations are processed by organizational members, using their own discourse.

Doctor of Philosophy / Department of Computing and Information Sciences / Gurdip Singh / Cyber-Physical Systems (CPSs) represent the next-generation systems characterized by strong coupling of computing, sensing, communication, and control technologies. They have the potential to transform our world with more intelligent and efficient systems, such as Smart Home, Intelligent Transportation System, Energy-Aware Building, Smart Power Grid, and Surgical Robot. A CPS is composed of a computational and a physical subsystem. The computational subsystem monitors, coordinates and controls operations of the physical subsystem to create desired physical effects, while the physical subsystem performs physical operations and gives feedback to the computational subsystem. This dissertation contributes to the research of CPSs by proposing a new transaction model for Environmental Resource Dependent Cyber-Physical Systems (ERDCPSs). The physical operations of such type of CPSs rely on environmental resources, and they are commonly seen in areas such as transportation and manufacturing. For example, an autonomous car views road segments as resources to make movements and a warehouse robot views storage spaces as resources to fetch and place goods. The operating environment of such CPSs, CPS Network, contains multiple CPS entities that share common environmental resources and interact with each other through usages of these resources. We model physical operations of an ERDCPS as a set of transactions of different types that achieve different goals, and each transaction consists of a sequence of actions. A transaction or an action may require environmental resources for its operations, and the usage of an environmental resource is precise in both time and space. Moreover, a successful execution of a transaction or an action requires exclusive access to certain resources. Transactions from different CPS entities of a CPS Network constitute a schedule. Since environmental resources are shared, transactions in the schedule may have conflicts in using these resources. A schedule must remain consistent to avoid unexpected consequences caused by resource usage conflicts between transactions. A two-phase commit algorithm is proposed to process transactions. In the pre-commit phase, a transaction is scheduled by reserving usage times of required resources, and potential conflicts are detected and resolved using different strategies, such as Win-Lose, Win-Win, and Transaction Preemption. Two general algorithms are presented to process transactions in the pre-commit phase for both centralized and distributed resource management environments. In the commit phase, a transaction is executed using reserved resources. An exception occurs when the real-time resource usage is different from what has been predicted. By doing internal and external check before a scheduled transaction is executed, exceptions can be detected and handled properly. A simulation platform (CPSNET) is developed to simulate the transaction model. The simulation platform simulates a CPS Network, where different CPS entities coordinate resource usages of their transactions through a Communication Network. Depending on the resource management environment, a Resource Server may exist in the CPS Network to manage resource usages of all CPS entities. The simulation platform is highly configurable and configuration of the simulation environment, CPS entities and two-phase commit algorithm are supported. Moreover, various statistical information and operation logs are provided to monitor and evaluate the platform itself and the transaction model. Seven groups of simulation experiments are carried out to verify the simulation platform and the transaction model. Simulation results show that the platform is capable of simulating a large load of CPS entities and transactions, and entities and components perform their functions correctly with respect to the processing of transactions. The two-phase commit algorithm is evaluated, and the results show that, compared with traditional cases where no conflict resolving is applied or a conflicting transaction is directly aborted, the proposed conflict resolving strategies improve the schedule productivity by allowing more transactions to be executed and the scheduling throughput by maintaining a higher concurrency level.