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Throughput of wireless packet transfer generally depends on the signal strength of wireless communication. The architecture of Wireless Distribution System (WDS) in an IEEE 802.11-based environment can avoid the decline of wireless signals and keep the data packet throughput by delivering packets among access points. This paper focuses on WDS and proposes an algorithm of Maximum Independent Set (MIS) to determine the subset of access points and reduce its computation time for wireless data packet transmission and achieving throughput improvement.

We study the online linear optimization problem, in which a player has to make repeated online decisions with linear loss functions and hopes to achieve a small regret. We consider a natural restriction of this problem in which the loss functions have a small deviation, measured by the sum of the distances between every two consecutive loss functions. At the same time, we also consider a natural generalization, in which the regret is measured against a dynamic offline algorithm which can play different strategies in different rounds, but under the constraint that their deviation is small. We show that in this new setting, an online algorithm modified from the gradient descent algorithm can still achieve a small regret, which can be characterized in terms of the deviation of loss functions and the deviation of the offline algorithm. For the closely related online decision problem, we show that an online algorithm modified from the Hedge algorithm can also achieve a small regret in this new setting.

Cloud computing paradigm is becoming very popular these days. However, it does not include wireless sensors and mobile phones which are needed to enable new emerging applications such as remote home medical monitoring. Therefore, a combined Cloud-Internet of Things (IoT) paradigm provides scalable on-demand data storage and resilient computation power at the cloud side as well as anytime, anywhere health data monitoring at the IoT side. As both the privacy of personal medical data and flexible data access should be provided, the data in the Cloud are always encrypted and access control must be operated upon encrypted data together with being fine-grained to support diverse accessibility. Since a plain combination of encryption before access control is not robust and flexible, we propose a scheme with tailored design. The scheme makes use of cipher-policy attributes based encryption to empower robustness and flexibility. The scheme describes a general framework to solve the secure requirements, and leaves the flexibility of concrete constructions intentionally.

In this paper, we study an extension of atomic routing games for multi-class communication networks with quality of service requirements, which can be formulated as a network management scheme. Atomic routing games are non-cooperative games with multiple selfish players, where each player has to choose a path in a given graph to route his traffic, and then pays the corresponding cost. We develop a mixed-integer nonlinear programming model for the network management scheme in this class-based communication network. The analysis of this work offers appropriate resource allocation and a routing database identifying suitable end-to-end paths upon each connection request.

General aviation has been promoted by Small Aircraft Transportation System (SATS) to broaden air transportation services. Under such development, the National Airspace System (NAS) will change dramatically in congested airspace. In this decade, the unmanned aerial vehicle (UAV) has rapidly growing into civilian applications. Low altitude airspace becomes more crowded. As a result, collision avoidance for low altitude flights will become a serious concern to aviation safety. Varieties of conflict detection and resolution (CD&R) were required under multiple maneuvering dimensions for GA and UAV. This paper focuses on efficient collision avoidance logic for GA and UAV based on ADS-R for NextGen. Heading change of horizontal resolution is more suitable for small GA or UAV flying in low altitude in the proposed CD&R model. Simulations using real ultralight flight data are tested to verify the performance of the proposed CD&R.

A Boolean function f : {0, 1}n → {0, 1} is called nondegenerate if f depends on all its n variables. We show that, for any nondegenerate function f, there exists a variable x i such that at least one of the restrictions f ↾xi=0 or f ↾xi=1 must depend on all the remaining n − 1 variables. We also consider lower bounds on the degrees of polynomials representing a Boolean function over different rings. Let d q (f) be the degree of the (unique) polynomial over the ring ℤ q exactly representing f. For distinct primes p i let m = Πr i=1 pei i . Then, we show that any nondegenerate symmetric Boolean function f must have m · d p1 e 1 (f)…d pr e r (f) > n. We use the existence of nondegenerate subfunctions to prove degree lower bounds on random functions. Specifically, we show that m · d p1 e 1 (f)…d pr e r (f) > lg n − 1 holds for almost all f when f is chosen uniformly at random from all n-variate Boolean functions. Our proof uses the second moment method to show that a random f must almost always contain a nondegenerate symmetric subfunction on at least lg n − 1 variables. It follows that an n-variate nondegenerate symmetric Boolean function can have degree o(√n) over at most one finite field and that almost all f can have degree o(√lg n) over at most one finite field.

A variety of different control methods have been reported to achieve adaptive voltage position (AVP). In this paper, a new control method NAVP (native adaptive voltage positioning) was proposed and implemented. It features good performances in phase-current sharing, transient response and DC output voltage regulation. Discussions about compensator design for this method is also included. Simulations results and silicon implementation of this control method verified the concept.