9607875
Using Dataflow Information to Improve Inter-Workflow Instance Concurrency
The control-flow-based design of traditional batch scheduling systems (i.e., Job A must finish before Job B is started) can constrain the concurrency in schedulers for high-performance computing (HPC) workloads. There are two main problems. First, the control-flow graph, representing the workflow, may be inherently limited in its degree of concurrency. Second, if the naming strategy of the input and output files of jobs is simplistic, there may be a filename conflict problem when multiple instances of the same workflow run concurrently.
20945105
Real-Time Moving Vehicle Detection With Cast Shadow Removal in Video Based on Conditional Random Field
This paper presents an approach of moving vehicle detection and cast shadow removal for video based traffic monitoring. Based on conditional random field, spatial and temporal dependencies in traffic scenes are formulated under a probabilistic discriminative framework, where contextual constraints during the detection process can be adaptively adjusted in terms of data-dependent neighborhood interaction. Computationally efficient algorithm has been developed to discriminate moving cast shadows and handle nonstationary background processes for real-time vehicle detection in video streams. Experimental results show that the proposed approach effectively fuses contextual dependencies and robustly detects moving vehicles under heavy shadows even in grayscale video.
13511504
Non-Rigid Object Alignment with a Mismatch Template Based on Exhaustive Local Search
Non-rigid object alignment is especially challenging when only a single appearance template is available and target and template images fail to match. Two sources of discrepancy between target and template are changes in illumination and non-rigid motion. Because most existing methods rely on a holistic representation for the alignment process, they require multiple training images to capture appearance variance. We developed a patch-based method that requires only a single appearance template of the object. Specifically, we fit the patch-based face model to an unseen image using an exhaustive local search and constrain the local warp updates within a global warping space. Our approach is not limited to intensity values or gradients, and therefore offers a natural framework to integrate multiple local features, such as filter responses, to increase robustness to large initialization error, illumination changes and non-rigid deformations. This approach was evaluated experimentally on more than 100 subjects for multiple illumination conditions and facial expressions. In all the experiments, our patch-based method outperforms the holistic gradient descent method in terms of accuracy and robustness of feature alignment and image registration.
2947494
High Resolution Tracking of Non-Rigid Motion of Densely Sampled 3D Data Using Harmonic Maps
Abstract
We present a novel automatic method for high resolution, non-rigid dense 3D point tracking. High quality dense point clouds of non-rigid geometry moving at video speeds are acquired using a phase-shifting structured light ranging technique. To use such data for the temporal study of subtle motions such as those seen in facial expressions, an efficient non-rigid 3D motion tracking algorithm is needed to establish inter-frame correspondences. The novelty of this paper is the development of an algorithmic framework for 3D tracking that unifies tracking of intensity and geometric features, using harmonic maps with added feature correspondence constraints. While the previous uses of harmonic maps provided only global alignment, the proposed introduction of interior feature constraints allows to track non-rigid deformations accurately as well. The harmonic map between two topological disks is a diffeomorphism with minimal stretching energy and bounded angle distortion. The map is stable, insensitive to resolution changes and is robust to noise. Due to the strong implicit and explicit smoothness constraints imposed by the algorithm and the high-resolution data, the resulting registration/deformation field is smooth, continuous and gives dense one-to-one inter-frame correspondences. Our method is validated through a series of experiments demonstrating its accuracy and efficiency.

46437694
Estimation of multiple directional illuminants from a single image
We present a new method for the detection and estimation of multiple directional illuminants, using only one single image of an object with known geometry. It obviates the need to modify the imaged scene by inserting calibration objects of any particular geometry, relying instead on partial knowledge of the geometry of the scene. We first develop our method for the case of a Lambertian sphere with known size, illuminated by a set of directional light sources. A novel and robust way is proposed to segment the surface into regions, with each region illuminated by a different set of sources. Our region-based least-squares method is impervious to noise and missing data, which is crucial to extending the method to arbitrary smooth geometry and to surfaces having both Lambertian and specular properties. We propose a novel methodology that integrates information from shadows and shading in the presence of strong directional sources of illumination, even when significant non-directional sources exist in the scene and the object surface is not Lambertian. We demonstrate experimentally the accuracy of our method, both in detecting the number of light sources and in estimating their directions, by testing on images of a variety of synthetic and real objects.
9142519
Utilizing field usage patterns for Java heap space optimization
This research studies the characteristics of field usage patterns in the SpecJVM98 benchmarks. It finds that multiple object instances of the same class often exhibit different field-usage patterns. Motivated by this observation, we designed a heap compression mechanism that classifies object instances at runtime based on their field-usage patterns and eliminates unused fields to save space. To achieve the maximum space savings while minimizing the space and time overhead, our design combines three interrelated techniques in a novel manner: runtime object instance classification, field virtualization, and bidirectional object layout. An experimental evaluation reveals that this mechanism can reduce the maximum heap occupancy of SpecJVM98 benchmarks by up to 18% and 14% on average while keeping the application execution overhead low.
15156880
Adaptive Foreground and Shadow Detection in Image Sequences
This paper presents a novel method of foreground segmentation that distinguishes moving objects from their moving cast shadows in monocular image sequences. The models of background, edge information, and shadow are set up and adaptively updated. A Bayesian belief network is proposed to describe the relationships among the segmentation label, background, intensity, and edge information. The notion of Markov random field is used to encourage the spatial connectivity of the segmented regions. The solution is obtained by maximizing the posterior possibility density of the segmentation field.
16403865
Contamination Level and Speciation of Heavy Metals in Sediments from Yundang Lake, Xiamen
Yundang Lake is an important area for living and traveling in Xiamen Island. Severe pollution and sedimentation have been found in the lake, and then the dredging is needed. In order to assess the pollution level of dredged material, sediments from 6 stations in the Yundang Lake were sampled for heavy metal contamination, speciation analysis, and adsorption-desorption experiment in April 2003. Heavy metals concentrations varied from 21.96~848.38 mg/kg for Cu, 51.11~398.25 mg/kg for Pb, 121.60~4301.25 mg/kg for Zn, 0.00~14.71 mg/kg for Cd and 0.70~31.18 mg/kg for total Hg, respectively. The average concentrations of metals (Cu, Zn, Cd, and total Hg) are almost much higher than the secondary standard criteria of national marine sediment quality. According to the mean values of pollution index (Pi), the order of pollution level for heavy metals is as following: Hg ≫Cd ≫Zn ≫Cu ≫Pb. The results from the concentrations and Pi values of selected metals suggest that the study area has been significantly contaminated with heavy metals, and the plan that transferring dredged material to the dumping area must be forbidden. Similar chemical fractionation distribution for each metal is found in the outer lake and Songbai Lake, except for Hg. The main fraction for selected metals is the residual species, except for Cd in station Y17. It indicates that those heavy metals exhibit low biological availability in study area. Both speciation analysis and adsorption-desorption experiment show that the effects on the heavy metals in disposal area resulting from dredging at the Yundang Lake are not significant and the dredged material is fit to be stored at the reclamation region.
35134245
Single Table Access Using Multiple Indexes: Optimization, Execution, and Concurrency Control Techniques
Many data base management systems' query optimizers choose at most one index for accessing the records of a table in a given query, even though many indexes may exist on the table. In spite of the fact that there are some systems which use multiple indexes, very little has been published about the concurrency control or query optimization implications (e.g., deciding how many indexes to use) of using multiple indexes. This paper addresses these issues and presents solutions to the associated problems. Techniques are presented for the efficient handling of record ID lists, elimination of some locking, and determination of how many and which indexes to use. The techniques are adaptive in the sense that the execution strategies may be modified at run-time (e.g., not use some indexes which were to have been used), if the assumptions made at optimization-time (e.g., about selectivities) turn out to be wrong. Opportunities for exploiting parallelism are also identified. A subset of our ideas have been implemented in IBM's DB2 V2R2 relational data base management system.
35951417
Tree-based Burst Aggregation in Optical Burst Switching Networks
The invention is a surface light source device capable of effectively producing polarized illumination light. The output angle of a representative beam C3 representing P-polarized component of output light from an emission surface 5 of the light guide plate 1 is about 75 DEG . Where P-polarization component of representative beam C3 is 100 (reference value), and the S-polarized component is 42.2. Representative beam C3 enters from an air layer AR to a flat surface 24g of a prism sheet 24, and then goes into the inside of prism sheet 24. At this stage the P-polarization component is 89.3 whereas the S-polarization component is 25.5. Beam C3 is incident on a slant surface 24d from its inside at an angle proximating the normal, and propagates into air layer AR between prism sheets 24, 34. Beam C3 impinges on a flat surface 34g of a prism sheet 34 while its corresponding part passes through the inside of prism sheet 34. At this stage its P-polarization component is 83.9 and its S-polarization component is 22.3. Beam C3 enters from the inside of one slope 34d of the prism array at the angle of incidence of 31 DEG . Its greater part is output to external air layer AR as illumination light substantially in the front direction.
55331569
'No representation without information flow': measuring efficacy and efficiency of representationan: an information theoretic approach
Representation is a key concept for semiotics and for information systems. Stamper's framework may be seen outlining what is required for the efficacy of signs in standing for (i.e., representing) something else in an organization, among many others. We explore how the efficacy and the efficiency of representation may be measured, which seems overlooked in available literature of information systems and organizational semiotics. And we approach this problem from the perspective of what we call the 'information carrying' relation between the representation and the represented. We model the represented as an information source and the representation an information carrier, and the 'representing' relationship between them as that of 'information carrying'. That is, information is carried and therefore flows. These then are further modeled mathematically as random variables and random events, and a special relationship between random events. This approach enables us to reveal a necessary condition for the efficacy and the efficiency of representation, and to measure it. To this end we extend Dretske's semantic theory of information. The conviction that we put forward here is 'No representation without information flow', based upon which the efficacy and efficiency of a representation system may be measurable.