2597775
Re-cinematography: improving the camera dynamics of casual video
This paper presents an approach to post-processing casually captured videos to improve apparent camera movement. Re-cinematography transforms each frame of a video such that the video better follows cinematic conventions. The approach breaks videos into shorter segments. For segments of the source video where the camera is relatively static, re-cinematography uses image stabilization to make the result look locked-down. For segments with camera motions, camera paths are keyframed automatically and interpolated with matrix logarithms to give velocity-profiled movements that appear intentional and directed. The approach automatically balances the tradeoff between motion smoothness and distortion to the original imagery. Results from our prototype show improvements to poor quality home videos.
16557870
Collaboration upon Heterogeneous Platforms - from Desktop PC to Handheld Device
Nowadays, handheld wireless devices are being widely used by people to collaborate with one another using same handheld device in field or using desktop PC in office. Therefore, to study the effects of platform heterogeneity on task performance in collaborative virtual environments (CVEs) is helpful to improve future collaboration efficiency. In this paper, an experiment with highly interactive task was designed to study these effects. The task performance was evaluated under different combinations of three platforms: PC with a sensor, PDA with a stylus and PDA with direction buttons. The experiment results indicate that for simple 3D collaboration task, if right type of visualization and input device was chosen, we would be satisfied with performance both on homogeneous platforms and heterogeneous platforms
953854
Efficient Schemes for Monte Carlo Markov Chain Algorithms in Global Illumination
Current MCMC algorithms are limited from achieving high rendering efficiency due to possibly high failure rates in caustics perturbations and stratified exploration of the image plane. In this paper we improve the MCMC approach significantly by introducing new lens perturbation and new path-generation methods. The new lens perturbation method simplifies the computation and control of caustics perturbation and can increase the perturbation success rate. The new path-generation methods aim to concentrate more computation on "high perceptual variance" regions and "hard-to-find-but-important" paths. We implement these schemes in the Population Monte Carlo Energy Redistribution framework to demonstrate the effectiveness of these improvements. In addition., we discuss how to add these new schemes into the Energy Redistribution Path Tracing and Metropolis Light Transport algorithms. Our results show that rendering efficiency is improved with these new schemes.
8081608
An analytic model for Ge/Si core/shell nanowire MOSFETs considering drift-diffusion and ballistic transport
In this paper an analytic model for Ge/Si core/shell nanowire MOSFETs (NWFETs) is developed. First, the electrostatic potential and charge model are derived out from classical device physics. Then the drift-diffusion drain current model is obtained and verified by comparisons with the numerical simulation. The ballistic current model is obtained with the approximately described quantummechanical effect through modifying the intrinsic carrier concentration under 2-dimensional confinement. With the proposed model, the performances of Ge/Si core/shell NWFETs are analyzed and significant characteristics are demonstrated in details. The analytic model in this paper provides a framework for further developing compact models of the NWFETs with Ge/Si core/shell heterostructure for circuit design and simulation.
10172928
Texture-Consistent Shadow Removal
This paper presents an approach to shadow removal that preserves texture consistency between the original shadow and lit area. Illumination reduction in the shadow area not only darkens that area, but also changes the texture characteristics there. We achieve texture-consistent shadow removal by constructing a shadow-free and texture-consistent gradient field. First, we estimate an illumination change surface which causes the shadow and remove the gradients it induces. We approximate the illumination change surface with illumination change splines across the shadow boundary. We formulate estimating these splines as an optimization problem which balances the smoothness between the neighboring splines and their fitness to the image data. Second, we sample the shadow effect on the texture characteristics in the umbra and lit area near the shadow boundary, and remove it by transforming the gradients inside the shadow area to be compatible with the lit area. Experiments on photos from Flickr demonstrate the effectiveness of our method.
39158542
A New Algorithm of Gray Watermark Embedding
The problems of the digital information transmission safety, its’ copyright protection etc. are seriously increase. Digital watermark is one of the good solutions for many problems mentioned above. Generally the watermark information is a one-dimension random signal. Two-dimension gray watermark is difficult to guarantee the robustness of the information embedding. Put a new kind of discrete wavelet transform (DWT) and the singular value decompose (SVD) on two-dimension gray watermark, the watermark becomes very strong robust to the compression, noise, low pass filter, high pass filter and median filter. It is useful for the safety of digital information transmission and its copyright protection.
15004157
A Semantic QoS-Aware Discovery Framework for Web Services
Augmenting web services with explicit semantics forms the foundation of Service Oriented Architectures (SOAs) automation. As more and more Semantic Web Services (SWSs) are deployed, similar SWSs could have quite different quality-of-service (QoS) levels. The QoS-aware discovery becomes an important challenge. While some efforts try to solve it via Constraint Programming (CP), they suffer from the purely syntactic matchmaking method. Furthermore, the construction of constraints and the selection of services are completely dependent on the literal translation from QoS descriptions, which increase obstacles to actually apply CP. In this paper, we propose a semantic QoS-aware framework for SWSs discovery by combining the semantic matchmaking and CP. Initially, a QoS ontology is presented to define QoS data into service descriptions. Then the ontology reasoning is adopted to change previous syntactic matchmaking into a semantic way. Through confirming the compatibility of concepts, complex QoS conditions are solved as constraints and a selection algorithm is proposed to obtain the optimal offer. Finally, the prototype implementation of our framework is discussed and a SWSs discovery case is used to illustrate the comprehensive discovery process.
15887278
A novel analytical scheme to compute the n-fold convolution of exponential-sum distribution functions
A general analytical scheme for computing the n-fold convolution of exponential-sum distribution functions has been developed in this paper. The n-fold convolution is first expressed by multiple sums of recursive integrals. These recursive integrals are then reconstructed with a series of delta functions to avoid separations of integrations. Part of the recursive integrals has been solved analytically by either direct integration or with Maple-like symbolic software packages. The general analytical solution of the n-fold convolution of exponential-sum distribution functions is obtained in two steps: first developing a general pattern of Laplace transform of the recursive integrals, and then performing an inverse Laplace transform operation to the general pattern of the developed Laplace transform. The solution presented in this paper provides another option for computing the n-fold convolution of exponential-sum distribution functions.
36831968
Evaluating and Comparing Biomedical Term Identification Systems
In this paper, we propose a term identification system using conditional random fields (CRFs) on two biomedical datasets. Through employing several sets of experiments, we make a comprehensive investigation for different types of features. The final experimental results reflect that with carefully designed features i.e., adding not only the individual and dynamic features but also the combinational features, our system can identify biomedical terms with fairly high accuracy on both datasets, compared with other top systems already published in the literature.
45720537
Bayesian Network Structure Ensemble Learning
Bayesian networks (BNs) have been widely used for learning model structures of a domain in the area of data mining and knowledge discovery. This paper incorporates ensemble learning into BN structure learning algorithms and presents a novel ensemble BN structure learning approach. Based on the Markov condition and the faithfulness condition of BN structure learning, our ensemble approach proposes a novel sample decomposition technique and a components integration technique. The experimental results reveal that our ensemble BN structure learning approach can achieve an improved result compared with individual BN structure learning approach in terms of accuracy.
42839671
A Novel Integrated Supporting System for Mesh-Pull Based P2P IPTV
This paper presents a novel integrated supporting system for the mesh-pull based P2P IPTV. The proposed system can monitor the service quality of each overlays within the system by initiating random walks to sample key metrics of the system periodically and analyze the service quality statistically, and improve them to some extend. When the service quality is below the threshold, the system will increase its upload bandwidth adaptive to the workload of the system. The supporting system will allocate its bandwidth among multiple overlays to get the as much revenue as possible. This paper presents the design of this architecture and describes its functions and shows its adaptability to the high dynamic nature of p2p IPTV system and fitness for commercial deployment. At last we verify the feasibility of the architecture by simulation, and the results show its performance and adaptability.