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Three essential criteria are important for social activity planning: (1) finding attendees familiar with the initiator, (2) ensuring most attendees have tight social relations with each other, and (3) selecting an activity period available to all. In this paper, we propose the Social-Temporal Group Query (STGQ) to find suitable time and attendees with minimum total social distance. We first prove that the problem is NP-hard and inapproximable within any ratio. Next, we design two algorithms, SGSelect and STGSelect, which include effective pruning techniques to substantially reduce running time. Moreover, as users may iteratively adjust query parameters to fine tune the results, we study the problem of Subsequent Social Group Query (SSGQ). We propose the Accumulative Search Tree and Social Boundary, to cache and index intermediate results of previous queries in order to accelerate subsequent query processing. Experimental results indicate that SGSelect and STGSelect are significantly more efficient than baseline approaches. With the caching mechanisms, processing time of subsequent queries can be further reduced by 50-75 percent. We conduct a user study to compare the proposed approach with manual activity coordination. The results show that our approach obtains higher quality solutions with lower coordination effort, thereby increasing the users’ willingness to organize activities. [ABSTRACT FROM AUTHOR]

This article presents LightPainter, an interactive tool that promotes creative long-exposure photography through an intuitive drawing metaphor and flexible spatiotemporal mapping from videos to composite images. We discuss the power of software-defined exposure and the tools capability to facilitate creating sophisticated long-exposure effects in challenging scenarios. [ABSTRACT FROM AUTHOR]

Both copper (Cu) and silver (Ag) have been studied extensively for electrical conductor applications. To expand the applications, two bonding designs were implemented in this paper. For the first design, a 50- \mu \textm Ag layer was annealed at 400 °C to increase Ag grain size, thereby making it more ductile. For the second design, a 5- \mu \textm Ag layer with cavities was created to release the thermal induced stress and allow easier plastic deformation for the bonding medium. For both designs, the resulting Cu substrates were bonded to Cu chips by the solid-state bonding process. The cross sections of bonded samples show no visible voids or gaps on Cu/Ag and Ag/Cu interfaces. The breaking forces of ten samples tested far exceed the requirement specified in the military standards MIL-STD-883J Method 2019.9. The successful demonstrations of solid-state bonding between Ag and Cu should open the possibility of bringing alternatives for bonding methods in the field of electronic packaging. [ABSTRACT FROM PUBLISHER]

In this paper, we present an orientation inference framework for reconstructing implicit surfaces from unoriented point clouds. The proposed method starts from building a surface approximation hierarchy comprising of a set of unoriented local surfaces, which are represented as a weighted combination of radial basis functions. We formulate the determination of the globally consistent orientation as a graph optimization problem by treating the local implicit patches as nodes. An energy function is defined to penalize inconsistent orientation changes by checking the sign consistency between neighboring local surfaces. An optimal labeling of the graph nodes indicating the orientation of each local surface can, thus, be obtained by minimizing the total energy defined on the graph. The local inference results are propagated over the model in a front-propagation fashion to obtain the global solution. The reconstructed surfaces are consolidated by a simple and effective inspection procedure to locate the erroneously fitted local surfaces. A progressive reconstruction algorithm that iteratively includes more oriented points to improve the fitting accuracy and efficiently updates the RBF coefficients is proposed. We demonstrate the performance of the proposed method by showing the surface reconstruction results on some real-world 3-D data sets with comparison to those by using the previous methods. [ABSTRACT FROM AUTHOR]

A new photo retrieval system for mobile devices is proposed. The system can be used to search for photos with similar spatial layouts efficiently, and it adopts an image segmentation algorithm that extracts features of image regions based on K-Means clustering. Since K-Means is computationally intensive for real-time applications and prone to generate clustering results with local optima, parallel hardware architectures are designed to meet the real-time requirement of the retrieval process. Experiments show that the proposed algorithm in the photo retrieval system obtains better mean average precision than other methods, and it is tested with image recognition problems. The robustness of the algorithm is also evaluated with noise and image blurring. Besides, the proposed K-Means hardware can provide a trade-off between the execution time and the retrieval performance on the software and hardware cosimulation platform. The contribution of this work is twofold. The first is the development of a photo retrieval framework for mobile devices, where a new texture feature is employed in the algorithm to enhance the retrieval performance. The other is the integration of the K-Means hardware accelerator and the photo retrieval system. The hardware architecture is analyzed, and the specifications are compared with previous works. [ABSTRACT FROM AUTHOR]