In wireless sensor networks, the maximum lifetime routing problem has received increasing attention among researchers. There are several critical features that need to be considered while designing a wireless sensor networks such as cost, network lifetime and Quality of service. Due to the limitation on the energy of sensor nodes, energy efficient routing is a very important issue in sensor networks. Therefore, to prolong the lifetime of the sensor nodes, designing efficient routing protocols is critical. One solution is to formulate the routing problem as a linear programming problem by maximizing the time at which the first node runs out of battery. In this paper, with the notion of maximizing the system lifetime, we implemented a new heuristic and evaluated the performance of it with the existing algorithm called flow augmentation algorithm. Further, our experimental results demonstrate that the proposed algorithm significantly outperform FA algorithm, in terms of system lifetime.

Delay Tolerant Networks (DTN) are high delay networks with intermittent connectivity. Transport protocols developed either for high bandwidth networks or low delay networks suffer significantly on these type of networks. We have studied the impact of various transport protocols and application level protocols on a specific type of DTN namely Message Ferry Networks. At present there is no specific transport protocol that adapts well to the characteristics of Message Ferry networks. We developed a protocol that is well suited for Message ferry networks. Our protocol ensures major characteristics of a reliable transport protocol like in order delivery and reliable transfer of data without compromising on the throughput. We simulated our protocol by modifying the TCP process model in Opnet and compared it with standard TCP. The simulation results show a drastic improvement over the standard TCP protocol.

Service providers within an enterprise network are often governed by Client Service Contracts (CSC) that specify, among other constraints, the rate at which a particular service instance may be accessed. The service can be accessed via multiple points (typically middleware appliances) in a proxy tier configuration. The CSC and thus the rate specified have to be collectively respected by all the middleware appliances. The appliances locally shape the service requests to respect the global contract. We investigate the case where the CSC limits the rate to a service to X requests with an enforcement/observation interval of T seconds across all the middleware appliances. In this thesis, we define and evaluate the performance of Credit-based Algorithm for Service Traffic Shaping (CASTS), a decentralized algorithm for service traffic shaping in middleware appliances, in both a simulation and a realistic production level enterprise network setting. We show that CASTS respects the CSC and improves the responsiveness of the system to the variations of the input rate and leads to larger service capacity when compared to the traditional static allocation approach.

Advance reservation of lightpaths in an optical network has become a popular concept of reserving network resources in support of Grid applications. In this thesis, we have evaluated and compared several algorithms for dynamic scheduling of lightpaths using a flexible advance reservation model. The main aim is to find the best scheduling policy that improves network utilization and minimizes blocking. The scheduling of lightpaths involve both routing and wavelength assignment. Our simulation results show that minimum cost adaptive routing where link costs are determined by the current and future usage of the link provides the minimum blocking. Moreover, searching for k alternate paths within the scheduling window significantly improves the performance. For wavelength assignment, we have used a scheme that reduces fragmentation by minimizing unused leading or trailing gaps. We have also analyzed approaches for failure recovery and lightpath re-optimization. Finally, an advance reservation scheme needs timely information regarding the status of the optical links. To this end, we have surveyed various monitoring tools and techniques and we have proposed a monitoring framework to support fast restoration.

The issue of insider threat is one that organizations have dealt with for many years. Insider threat research began in the early 80's, but has yet to provide satisfactory results despite the fact that insiders pose a greater threat to organizations than external attackers. One of the key issues relating to this problem is that the amount of collectable data is enormous and it is currently impossible to analyze all of it, for each insider, in a timely manner. The purpose of this research is to analyze a portion of this collectable data, process usage, and determine if this data is useful in identifying insiders. Identification of the person controlling the workstation is useful in environments where workstations are left unattended, even for a short amount of time. To do this, we developed an insider threat detection system based on the Naive Bayes method which examines process usage data and creates individual profiles for users. By comparing collected data to these profiles we are able to determine who is controlling the workstation with high accuracy. We are able to achieve true positive rates of 96\% while maintaining fewer than 0.5\% false positives.

The goal of this research is to estimate the capacity of wireless mesh networks (WMNs). WMNs have unique topology and traffic patterns when compared to conventional wireless Internet access networks. In WMNs, user nodes act as a host and a router simultaneously and form a meshed topology. Traffic is forwarded towards a gateway connected to the Internet by cooperating user nodes in a multihop fashion. Since the considered WMNs use IEEE 802.11 for medium access control and physical layer implementation, theoretical maximum throughput and fairness issues in IEEE 802.11 networks are investigated as a preliminary framework for the capacity estimation of WMN. Due to a centralized traffic pattern and meshed topology, forwarded traffic becomes heavier as it gets closer to the gateway. The characteristics of the traffic behavior in WMNs are thoroughly examined and an analytical solution for capacity estimation is presented. The analytical solution is derived for various topologies and validated using simulations.

This thesis studies the effect of non-negligible signaling delays on the performance of wavelength-assignment heuristics, wavelength reservation schemes, routing schemes, holding time (average being 1/μ) of the lightpaths and traffic loads (average being λ/μ), in second-generation optical wide area networks (WANs). A network simulator was developed using the C++ language for this study. The simulator supports any input topology with single or multi-fiber links, many routing schemes (static, alternate and dynamic), dynamic traffic loads, and may be modified easily to accomodate different wavelength-assignment policies. The signaling messages used, in our study, to establish lightpaths, follow the Constrained-Routing Label Distribution Protocol (CR-LDP) semantics. The problem studied here falls under the general category of Routing and Wavelength Assignment (RWA) Problem which has been proved to be NP-hard. Previous studies have mostly considered static routing (with static or dynamic traffic demand), and static traffic demand (with static or alternate routing) under zero propagation delays. A few papers in the recent past have studied the effect of signaling delays but have been limited in scope. We study the effect of varying holding times, compare random versus first-fit wavelength assignment policy, compare fixed versus alternate routing, compare backward wavelength reservation schemes to forward reservation schemes, and lastly study the effect of traffic loads. We find that, in general, the random wavelength assignment policy performs better than first-fit policy and that under certain conditions, alternate routing scheme performs worse than fixed routing scheme.

<p>Internationalization processes</p>

Internationalization processes

Due to globalization and other factors, the business environment of small and medium sized enterprises (SMEs) is radically changing. In order for these firms to cope with increased competition and business opportunities in globalised markets, they have to strengthen their innovative capabilities and internationalise their business activities (Rammer and Schmiele, 2008, p.3). In this paper, I investigate the determinants that drive highly technological SMES from Umea (Sweden) to other markets abroad and the paths followed by these SMES.The choice of Highly technological SMES (i.e. SMES with innovative solutions) is mainly due to the fact that they internationalise at a fast pace and often bypass the traditional methods of internationalisation proposed by the Uppsala model of internationalisation. The Uppsala model of internationalisation was used as a reference point where similarities and discrepancies between findings was analysed. In addition to this, a general analysis on how managerial internationalisation strategies are drawn was carefully outlined. Core focus is placed on the importance of resource evaluation, proper entry modes, networking and the inclusion of deinternationalisation as a contingency plan in case the market becomes unresponsive due to rise in cost or high competitive pressures.   By carrying out a qualitative research and a cross-sectional analysis of some four firms operating in the highly technological sector of the Swedish economy, I obtained findings that; Swedish SMEs do not seem to be pushed to internationalisation by increased competition (such as threat of market position through new entrants or a fierce price competition), but rather go abroad with innovative activities when they have a niche market position, i.e. a low number of competitors and a patent-based technology advantage (Rammer and Shmiele,2008,p.3). Concerning the paths followed by these SMEs to international markets, I outlined that the starting point of SMEs is to carry out an evaluation of their resources (physical, human and financial).Careful evaluation of these resources will enable managers detect if the company can cope with foreign expansion. With this information, they can seek for resources that are not internally possess by the company through establishing networks with distributors, firms, suppliers and their customers. With this network, the firm can obtain both market specific and general knowledge of the foreign market. With all this information at hand, the entry mode must be considered. It is of great importance because the cost and risk involve in foreign markets are mostly associated with the chosen entry mode. Because international expansion involves taking risk, I advise managers on setting up a threshold where they can withdraw if the value of the firm begins to drop. However, I urge them to be careful not to withdraw either prematurely or too late. Therefore, I conclude that though international expansion can help SMEs overcome resource constraints, they should however be careful on how they internationalised by following the paths I outlined.       Keywords; Internationalisation, Networking, Resourced Based Perspectives, International Entry Mode, SMEs, Deinternationalisation