1,524 research outputs found
Joint Energy Efficient and QoS-aware Path Allocation and VNF Placement for Service Function Chaining
Service Function Chaining (SFC) allows the forwarding of a traffic flow along
a chain of Virtual Network Functions (VNFs, e.g., IDS, firewall, and NAT).
Software Defined Networking (SDN) solutions can be used to support SFC reducing
the management complexity and the operational costs. One of the most critical
issues for the service and network providers is the reduction of energy
consumption, which should be achieved without impact to the quality of
services. In this paper, we propose a novel resource (re)allocation
architecture which enables energy-aware SFC for SDN-based networks. To this
end, we model the problems of VNF placement, allocation of VNFs to flows, and
flow routing as optimization problems. Thereafter, heuristic algorithms are
proposed for the different optimization problems, in order find near-optimal
solutions in acceptable times. The performance of the proposed algorithms are
numerically evaluated over a real-world topology and various network traffic
patterns. The results confirm that the proposed heuristic algorithms provide
near optimal solutions while their execution time is applicable for real-life
networks.Comment: Extended version of submitted paper - v7 - July 201
Egocentric Vision-based Future Vehicle Localization for Intelligent Driving Assistance Systems
Predicting the future location of vehicles is essential for safety-critical
applications such as advanced driver assistance systems (ADAS) and autonomous
driving. This paper introduces a novel approach to simultaneously predict both
the location and scale of target vehicles in the first-person (egocentric) view
of an ego-vehicle. We present a multi-stream recurrent neural network (RNN)
encoder-decoder model that separately captures both object location and scale
and pixel-level observations for future vehicle localization. We show that
incorporating dense optical flow improves prediction results significantly
since it captures information about motion as well as appearance change. We
also find that explicitly modeling future motion of the ego-vehicle improves
the prediction accuracy, which could be especially beneficial in intelligent
and automated vehicles that have motion planning capability. To evaluate the
performance of our approach, we present a new dataset of first-person videos
collected from a variety of scenarios at road intersections, which are
particularly challenging moments for prediction because vehicle trajectories
are diverse and dynamic.Comment: To appear on ICRA 201
Tight lower bound to the geometric measure of quantum discord
Dakic, Vedral and Brukner [Physical Review Letters \tf{105},190502 (2010)]
gave a geometric measure of quantum discord in a bipartite quantum state as the
distance of the state from the closest classical quantum (or zero discord)
state and derived an explicit formula for a two qubit state. Further, S.Luo and
S.Fu [Physical Review A \tf{82}, 034302 (2010)] obtained a generic form of this
geometric measure for a general bipartite state and established a lower bound.
In this brief report we obtain a rigorous lower bound to the geometric measure
of quantum discord in a general bipartite state which dominates that obtained
by S.Luo and S.Fu.Comment: 10 pages,2 figures. In the previous versions, a constraint was
ignored while optimizing the second term in Eq.(5), in which case, only a
lower bound on the geometric discord can be obtained. The title is also
consequently changed. Accepted in Phys.Rev.
Use of Unlabeled Samples for Mitigating the Hughes Phenomenon
The use of unlabeled samples in improving the performance of classifiers is studied. When the number of training samples is fixed and small, additional feature measurements may reduce the performance of a statistical classifier. It is shown that by using unlabeled samples, estimates of the parameters can be improved and therefore this phenomenon may be mitigated. Various methods for using unlabeled samples are reviewed and experimental results are provided
Reefer logistics and cool chain transport
Reefer logistics is an important part of the cool chain in which reefer containers are involved as the packaging for transporting perishable goods. Reefer logistics is challenging, as it deals with cost and time constraints as well as the product quality and sustainability requirements. In many situations, there is a trade-off between these factors (e.g., between transportation time and the quality of fresh products). Furthermore, considering the high value of reefers, the efficient logistics of is as important as the efficient cargo flows. This causes technical complications and the conflict of interests between actors, especially, between cargo owners (or shippers) and the asset owners (or transport/terminal operators). Improving the efficiency of reefer logistics calls for a thorough understanding of the trade-offs and complexities. This paper aims to help develop such an understanding using a systematic literature review and a socio-technical system analysis. The results can be used to provide managerial insights for actors involved in a cool chain to design tailored solutions for reefer
Entanglement Capacity of Nonlocal Hamiltonians : A Geometric Approach
We develop a geometric approach to quantify the capability of creating
entanglement for a general physical interaction acting on two qubits. We use
the entanglement measure proposed by us for -qubit pure states (PRA
\textbf{77}, 062334 (2008)). Our procedure reproduces the earlier results (PRL
\textbf{87}, 137901 (2001)). The geometric method has the distinct advantage
that it gives an experimental way to monitor the process of optimizing
entanglement production.Comment: 8 pages, 1 figure
A Simulated Annealing method to solve a generalized maximal covering location problem
The maximal covering location problem (MCLP) seeks to locate a predefined number of facilities in order to maximize the number of covered demand points. In a classical sense, MCLP has three main implicit assumptions: all or nothing coverage, individual coverage, and fixed coverage radius. By relaxing these assumptions, three classes of modelling formulations are extended: the gradual cover models, the cooperative cover models, and the variable radius models. In this paper, we develop a special form of MCLP which combines the characteristics of gradual cover models, cooperative cover models, and variable radius models. The proposed problem has many applications such as locating cell phone towers. The model is formulated as a mixed integer non-linear programming (MINLP). In addition, a simulated annealing algorithm is used to solve the resulted problem and the performance of the proposed method is evaluated with a set of randomly generated problems
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