8559794
Randomly accessible procedural animation of physically approximate turbulent motion
Complex virtual environments can be simulated with physical or procedural motion. Physical motion is more realistic, but requires the integration of an ordinary differential equation from an initial state. Procedural motion has the advantage of being randomly accessible, though it is not physically based. We combine these techniques into a multiresolution model. A coarse-level simulation is sampled to yield keyframes. Then a physical motion between keyframes is calculated and distorted to meet its boundary conditions. We demonstrate these ideas with a simple virtual world consisting of wind blowing trees and leaves that can be entered and experienced efficiently at any point in time.
7037192
Interactive material replacement in photographs
Material replacement has wide application throughout the entertainment industry, particularly for post-production make-up application or wardrobe adjustment. More generally, any low-cost mock-up object can be processed to have the appearance of expensive, high-quality materials. We demonstrate a new system that allows fast, intuitive material replacement in photographs. We extend recent work in object selection and fast texture synthesis, as well as develop a novel approach to shape-from-shading capable of handling objects with albedo changes. Each component of our system runs with interactive speed, allowing for easy experimentation and refinement of results.
16418680
Term feedback for information retrieval with language models
In this paper we study term-based feedback for information retrieval in the language modeling approach. With term feedback a user directly judges the relevance of individual terms without interaction with feedback documents, taking full control of the query expansion process. We propose a cluster-based method for selecting terms to present to the user for judgment, as well as effective algorithms for constructing refined query language models from user term feedback. Our algorithms are shown to bring significant improvement in retrieval accuracy over a non-feedback baseline, and achieve comparable performance to relevance feedback. They are helpful even when there are no relevant documents in the top.
13944296
Textureshop: texture synthesis as a photograph editing tool
We combine existing techniques for shape-from-shading and texture synthesis to create a new tool for texturing objects in photographs. Our approach clusters pixels with similar recovered normals into patches on which texture is synthesized. Distorting the texture based on the recovered normals creates the illusion that the texture adheres to the undulations of the photographed surface. Inconsistencies in the recovered surface are disguised by the graphcut blending of the individually textured patches. Further applications include the generation of detail on manually-shaded painting, extracting and synthesizing a displacement map from a texture swatch, and the embossed transfer of normals from one image to another, which would be difficult to create with current image processing packages.
5471705
Probabilistic Models for Expert Finding
A common task in many applications is to find persons who are knowledgeable about a given topic (i.e., expert finding). In this paper, we propose and develop a general probabilistic framework for studying expert finding problem and derive two families of generative models (candidate generation models and topic generation models) from the framework. These models subsume most existing language models proposed for expert finding. We further propose several techniques to improve the estimation of the proposed models, including incorporating topic expansion, using a mixture model to model candidate mentions in the supporting documents, and defining an email count-based prior in the topic generation model. Our experiments show that the proposed estimation strategies are all effective to improve retrieval accuracy.
14545049
An Axiomatic Approach to IR--UIUC TREC 2005 Robust Track Experiments
In this paper, we report our experiments in the TREC 2005 Robust Track. Our focus is to explore the use of a new axiomatic approach to information retrieval. Most existing retrieval models make the assumption that terms are independent of each other. Although such simplifying assumption has facilitated the construction of successful retrieval systems, the assumption is not true; words are related by use, and their similarity of occurrence in documents can reflect underlying semantic relations between terms. Our new method aims at incorporating term dependency relations into the axiomatic retrieval model in a natural way. In this paper, we describe the method and present analysis of our Robust-2005 evaluation results. The results show that the proposed method works equally well as the KL-divergence retrieval model with a mixture model feedback method. The performance can be further improved by using the external resources such as Google.
29388694
A fuzzy logic approach for detection of video shot boundaries
Video temporal segmentation is normally the first and important step for content-based video applications. Many features including the pixel difference, colour histogram, motion, and edge information etc. have been widely used and reported in the literature to detect shot cuts inside videos. Although existing research on shot cut detection is active and extensive, it still remains a challenge to achieve accurate detection of all types of shot boundaries with one single algorithm. In this paper, we propose a fuzzy logic approach to integrate hybrid features for detecting shot boundaries inside general videos. The fuzzy logic approach contains two processing modes, where one is dedicated to detection of abrupt shot cuts including those short dissolved shots, and the other for detection of gradual shot cuts. These two modes are unified by a mode-selector to decide which mode the scheme should work on in order to achieve the best possible detection performances. By using the publicly available test data set from Carleton University, extensive experiments were carried out and the test results illustrate that the proposed algorithm outperforms the representative existing algorithms in terms of the precision and recall rates.
44946141
The Design of an Observer-Based Neural Adaptive Controller for a Class of Nonlinear Systems with Input-Constrained
18215845
A hybrid scheme for temporal video segmentation
Video temporal segmentation is normally the first and important step for content-based video applications. Although existing research on shot cut detection is active and extensive, it still remains a challenge to achieve accurate detection of all types of shot boundaries. In this paper, we propose a hybrid scheme to combine some features and techniques for detecting all sorts of shot cuts inside general videos. The hybrid scheme contains two processing modes, which are unified by a mode-selector to decide which mode the scheme should work on in order to achieve accurate temporal video segmentation. Via using the publicly test data set from Carleton University, we report extensive experimental results to evaluate the proposed algorithm. In comparison with existing algorithms, the experimental results support that the proposed algorithm outperforms the benchmark in terms of the precision-recall rates in detecting all types of shot cuts.
27646240
Mining User Position Log for Construction of Personalized Activity Map
Consider a scenario in which a smart phone automatically saves the user's positional records for personalized location-based applications. The smart phone will infer patterns of user activities from the historical records and predict user's future movements. In this paper, we present algorithms for mining the evolving positional logs in order to identify places of significance to user and representative paths connecting these places, based on which a personalized activity map is constructed. In addition, the map is designed to contain information of speed and transition probabilities, which are used in predicting the user's future movements. Our experiments show that the user activity map well matches the actual traces and works effectively in predicting user's movements.
16979811
Neural adaptive control for a class of nonlinear systems with unknown deadzone
This paper focuses on the adaptive control of a class of nonlinear systems with unknown deadzone using neural networks. By constructing a deadzone pre-compensator, a neural adaptive control scheme is developed using backstepping design techniques. Transient performance is guaranteed and semi-globally uniformly ultimately bounded stability is obtained. Another feature of this scheme is that the neural networks reconstruction error bound is assumed to be unknown and can be estimated online. Simulation results are given to demonstrate the effectiveness of the proposed controller.