9609952
A survivable routing algorithm with differentiated domain protection based on a virtual topology graph in multi-domain optical networks
In this paper, we propose a novel differentiated domain protection (DDP) scheme to address survivability in multi-domain optical networks. Survivable routing in multi-domain networks is a challenging algorithmic problem because it requires choosing links that provide adequate protection both between domains and within domains that may offer different protection services. To satisfy the survivability requirements of different domains, DDP considers differentiated protection schemes, i.e., dedicated protection, shared protection, or no protection in different domains. In order to respect the principle of transparent management in multiple domains, DDP abstracts a multi-domain optical network to a virtual topology graph (VTG) for solving routing between domains. Simulation results show that DDP, unlike traditional schemes, can provide trade-off between protection methods and also allows better resource utilization.
7343144
A New Recovery Escalation Algorithm with Load Balancing and Backup Resources Sharing in Path Protected WDM Optical Networks
This paper proposes a new survivable algorithm, enhanced shared-path protection (ESPP), to tolerate multi-link failures in WDM optical networks. In ESPP, we consider the load balancing to reduce the blocking probability, use resources sharing to save backup resources, and perform recovery escalation to carry the affected traffic. Compared with the conventional algorithm, ESPP has better resource utilization ratio, lower blocking probability and higher protection ability. Simulation results are shown to be promising.
18135167
Localized and Integrated Topology Maintenance for Wireless Sensor Networks
The energy consumed by topology maintenance could be higher than that in the initialization stage and the cost will increase steadily with the turns of maintenance process. Therefore, when design a self-organization protocol for WSN, not only initialization cost should be considered but also the maintenance cost in the whole lifetime. Moreover, to reduce the footprint on system resource, the maintenance process should be integrated with the initialization process but not separated. We propose a localized and integrated topology maintenance algorithm in this paper. This algorithm could maintain the topology in a localized manner and the maintenance process is integrated with the initialization process by nature. Simulation results show it has less energy cost in the network lifetime than two other typical protocols.
5444016
Arbitrary warped document image restoration based on segmentation and Thin-Plate Splines
Warping is a common appearance in camera captured document images. It is the primary factor that makes such kind of document images hard to be recognized. Therefore it is necessary to restore warped document image before recognition. In this paper, a novel restore method is presented. The method takes a rough line segmentation and character segmentation firstly in order to estimate the warping direction. Then several pairs of key points mapping between the original image and the restored image are determined and thin-plate splines (TPS), which is an interpolation algorithm, is introduced to restore the image. Such process can effectively describe the warping direction of the document and successfully restore the image. Some experimental results show the effect of the image restoration and compare the recognition rate before and after the restoration based on a same OCR application.
6059000
Preserving User Location Privacy in Mobile Data Management Infrastructures
Location-based services, such as finding the nearest gas station, require users to supply their location information. However, a user's location can be tracked without her consent or knowledge. Lowering the spatial and temporal resolution of location data sent to the server has been proposed as a solution. Although this technique is effective in protecting privacy, it may be overkill and the quality of desired services can be severely affected. In this paper, we suggest a framework where uncertainty can be controlled to provide high quality and privacy-preserving services, and investigate how such a framework can be realized in the GPS and cellular network systems. Based on this framework, we suggest a data model to augment uncertainty to location data, and propose imprecise queries that hide the location of the query issuer and yields probabilistic results. We investigate the evaluation and quality aspects for a range query. We also provide novel methods to protect our solutions against trajectory-tracing. Experiments are conducted to examine the effectiveness of our approaches.
16765186
Insider DoS Attacks on Epidemic Propagation Strategies of Network Reprogramming in Wireless Sensor Networks
Network reprogramming is a crucial service in wireless sensor networks (WSNs) that relies on epidemic strategy for spreading software updates by just having a local view of the networks. Securing the process of network reprogramming is essential in some certain WSNs applications, state-of-the-art secure network reprogramming protocols for WSNs aim for the efficient source authentication and integrity verification of code image, however, due to the resource constrains of WSNs, existing secure network reprogramming protocols are vulnerable to Denial of Service (DoS) attacks when sensor nodes can be compromised (insider DoS attacks). In this paper, we identify different types of DoS attacks exploiting the epidemic propagation strategies used by Deluge and propose corresponding analysis models to attempt to quantify the cost of these attacks damage. Simulation further shows the impact of insider DoS attacks on network reprogramming in WSNs.
20797286
A Generic Validation Framework for Wideband MIMO Channel Models
In this paper, a generic framework for validating wideband MIMO channel models based on channel measurement results is proposed. The framework is formulated as a series of continuous functions (metrics) and a definition of distance of continuous function space (degree of approximation). The metrics characterize the MIMO channel from different perspectives, and the distance provides a quantitative measure of the degree of approximation for the specified model. Several fundamental metrics which reflect the spatial multiplexing gain, diversity capability, time and frequency variability, are derived for exploring the frequency-selective fading property. Based on an extensive measurement campaign at 5.25 GHz, the propagation channel is reconstructed by a WINNER-like model. The metrics are calculated from both the model generated channel realizations and the measured impulse response as a demonstration. The proposed framework can be applied to compare different channel models and to evaluate the simplified version of channel models.