Simulation and analysis of network traffic for efficient and reliable information transfer

With the growing commercial importance of the Internet and the development of new real-time, connection-oriented services like IP-telephony and electronic commerce resilience is becoming a key issue in the design of TP-based networks. Two emerging technologies, which can accomplish the task of efficient information transfer, are Multiprotocol Label Switching (MPLS) and Differentiated Services. A main benefit of MPLS is the ability to introduce traffic-engineering concepts due to its connection-oriented characteristic. With MPLS it is possible to assign different paths for packets through the network. Differentiated services divides traffic into different classes and treat them differently, especially when there is a shortage of network resources. In this thesis, a framework was proposed to integrate the above two technologies and its performance in providing load balancing and improving QoS was evaluated. Simulation and analysis of this framework demonstrated that the combination of MPLS and Differentiated services is a powerful tool for QoS provisioning in IP networks.

Perceiving Spanish in Miami: The Interaction of Dialect and National Labeling

The current study implements a speech perception experiment that interrogates local perceptions of Spanish varieties in Miami. Participants (N=292) listened to recordings of three Spanish varieties (Peninsular, Highland Colombian, and Post-Castro Cuban) and were given background information about the speakers, including the parents’ country of origin. In certain cases, the parents’ national-origin label matched the country of origin of the speaker, but otherwise the background information and voices were mismatched. The manipulation distinguishes perceptions determined by bottom-up cues (dialect) from top-down ones (social information). Participants then rated each voice for a range of personal characteristics and answered hypothetical questions about the speakers’ employment, family, and income. Results show clear top-down effects of the social information that often drive perceptions up or down depending on the traits themselves. Additionally, the data suggest differences in perceptions between Hispanic/non-Hispanic and Cuban/non-Cuban participants, although the Cuban participants do not drive the Hispanic participants’ perceptions.

Social construction of Geographic Information Systems. (Volumes I and II)

Geographic Information Systems (GIS) is an emerging information technology (IT) which promises to have large scale influences in how spatially distributed resources are managed. It has had applications in the management of issues as diverse as recovering from the disaster of Hurricane Andrew to aiding military operations in Desert Storm. Implementation of GIS systems is an important issue because there are high cost and time involvement in setting them up. An important component of the implementation problem is the "meaning" different groups of people who are influencing the implementation give to the technology. The research was based on the theory of (theoretical stance to the problem was based on the) "Social Construction of Knowledge" systems which assumes knowledge systems are subject to sociological analysis both in usage and in content. An interpretive research approach was adopted to inductively derive a model which explains how the "meanings" of a GIS are socially constructed. The research design entailed a comparative case analysis over two county sites which were using the same GIS for a variety of purposes. A total of 75 in-depth interviews were conducted to elicit interpretations of GIS. Results indicate that differences in how geographers and data-processors view the technology lead to different implementation patterns in the two sites.