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Collaborative filtering(CF) recommender systems are among the most popular approaches to solving the information overload problem in social networks by generating accurate predictions based on the ratings of similar users. Traditional CF recommenders suffer from lack of scalability while decentralized CF recommenders (DHT-based, Gossip-based etc.) have promised to alleviate this problem. Thus, in...
One of the main drawbacks of multi-carrier signals is the large envelope fluctuations. When multi-carrier signals with large envelopes pass through a power amplifier (PA), a degradation of adjacent channel leakage ratio (ACLR) happens. There exist two metrics commonly utilized to describe the envelope fluctuations of multi-carrier signals, i.e., peak-to-average power ratio (PAPR) and cubic metric...
To achieve highly efficient and flexible spectrum sharing in cognitive radio networks, we proposed a queuing method in combined channel aggregation and fragmentation (CAF) strategy for dynamic spectrum access (DSA). We derived the balance equation and evaluated various system performance metrics including blocking probability, dropping probability, spectrum utilization, throughput and mean queuing...
<div class="user">System designers face large challenges in the storage hierarchy when putting new optimizations into practice. We consider a recent storage cache optimization, designed to reduce cache requirements and boost I/O performance, which adapts to individual program behavior. This scheme leverages a quantum-based design, and we observe that the choice of time quanta...
In this paper, we use the NCTUns network simulator to study intelligent traffic signal control algorithms. NCTUns is both a microscopic traffic simulator and a network simulator. We imported the real-life map of a district of the Taipei city into NCTUns to let simulated vehicles move on the roads of the imported map. Then, we used a new and unique feature of NCTUns - each simulated vehicle moves towards...
The deployment of wireless ad-hoc networks compared to traditional infrastructure based networks offers several advantages such as fully distributed mobile operation, easy discovery of joining wireless devices and quick cheap network setup. The design of an effective routing protocol is one of the main challenges in the ad-hoc networking paradigm and the utilisation of an adequate link cost metric...
This paper proposes a modified marriage in honey-bee optimization for solving multiobjective optimization problems. Unlike the original marriage in honey-bee optimization, the proposed algorithm divides the objective space into several colonies, each of which has its own queen. The fitness of each solution is based on 3 parameters: the size of the colony, the number of dominating solutions, and the...
This paper focus on incorporating weight properties to enhance Web spam detection algorithms. Our proposed methodology adds this feature into Anti-TrustRank algorithm and call it weighted Anti-TrustRank algorithm to show the effectiveness of the weight properties using a new metric. Experiments are conducted on WEBSPAM-UK2006, a public Web spam dataset and have shown that weighted Anti-TrustRank significantly...
In this paper we present a method to simulate fluids on smooth surfaces of arbitrary topology using a graphics processing unit (GPU). To do this we use the parametrization of Cat mull-Clark subdivision surfaces and obtain the metric information of the distortion caused by this parametrization, so we can calculate differential operators of functions defined on this surface. Then the Navier-Stokes equations...
In this paper, histogram uniformization of digital images by means of the finite field cosine transform (FFCT) is examined. The approach consists in dividing the image into blocks and applying the FFCT, in a recursive manner, to each block. Simulations of the procedure show that the histogram of the transformed image exhibits a uniform shape and its pixels have low correlation with their neighbors...
Assessment of learning reflects the performance of an academic system. In reality, this performance is the cumulative impact of learning in each course of the program. Hence on completion of delivering a course in terms different components, it becomes important to understand the outcome produced, the knowledge and skills acquired by the students. One of the primary component of course assessment...
In this paper, we introduce a new approach for image quality assessment. The proposed method estimates similarity of frequency between a distorted image and a reference image using 8×8 block based DCT. Different from existing method such as SSIM (Structural Similarity Index Method) and PSNR, it does not use any data such as intensity, mean, variance, and covariance on the pixel domain. Instead, it...
We consider modeling of a nonlinear thin plate and a nonlinear thin shell under the following assumptions: (a) the materials are nonlinear; (b) the deflections are small (linear strain displacement relations). For a plate with a planar middle surface, we consider the bending of the plate to establish the strain energy, the equilibrium equations, and the motion equations. For a shell with a curved...
Motion estimation from cardiac image is a very important technique to study the architecture and function of heart. However quantitative motion analysis from cardiac images is still a challenging problem due to the complexity of cardiac motion and limitations in spatial and temporal image resolutions. We develop a robust temporally consistent diffeomorphic motion estimation algorithm based on mutual...
This paper presents a method to synthesize a realistic facial animation of a target person, driven by a facial performance video of another person. Different from traditional facial animation approaches, our system takes advantage of an existing facial performance database of the target person, and generates the final video by retrieving frames from the database that have similar expressions to the...
QoS computation plays an important role in Web service selection. It involves property value preprocessing aspect, user satisfaction calculation aspect, and aggregation of multiple QoS properties aspect. However, little attention has been paid to users participating in QoS computation. In this paper, we examine QoS computation from the angle of experienced users and novice users. An experienced user...
Spectral clustering makes use of spectral-graph structure of an affinity matrix to partition data into disjoint meaningful groups. Because of its elegance, efficiency and good performance, spectral clustering has become one of the most popular clustering methods. Traditional spectral clustering assumes a single affinity matrix. However, in many applications, there could be multiple potentially useful...
Grouping users in social networks is an important process that improves matching and recommendation activities in social networks. The data mining methods of clustering can be used in grouping the users in social networks. However, the existing general purpose clustering algorithms perform poorly on the social network data due to the special nature of users' data in social networks. One main reason...
We study fuzzy differential equations (FDEs) using the strongly generalized differentiability concept. Utilizing the characterization problem, we present approximate solutions of FDEs under Generalized differentiability by an equivalent system of ODEs. Then we extend midpoint approximation method and give its error, which guarantees pointwise convergence. An illustrative example is given.
Longitudinal data arises in many applications in which the goal is to understand changes in individual entities over time. In this paper, we present a method for analyzing longitudinal data that take values in a Riemannian manifold. A driving application is to characterize anatomical shape changes and to distinguish between trends in anatomy that are healthy versus those that are due to disease. We...
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