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Based on mathematical modeling of the principle of tapping with modified-tooth tap, the results of 2D simulation have been obtained, establishing 3D solid structure model of modified-tooth tap, simulating the actual manufacturing conditions in software of Solidworks, thus proving the possibility of tapping the thread of standard tooth profile angle with the modified-tooth tap of which the thread tooth...
The Simultaneous Localisation And Mapping (SLAM) for a camera moving in a scene is a long term research problem. Here we improve a recent visual SLAM which applies Local Bundle Adjustments (LBA) on selected key-frames of a video: we show how to correct the scale drift observed in long monocular video sequence using an additional odometry sensor. Our method and results are interesting for several reasons:...
This paper presents a tensorial representation of multiple projective cameras with arbitrary curvilinear motions. It enables us to define multilinear relationship of image points derived from non-rigid object motions viewed from multiple cameras with arbitrary curvilinear motions. We show the new multilinear relationship is useful for generating images of non-rigid object motions viewed from cameras...
This paper presents a constraint-based approach for video event recognition with probabilistic reasoning for handling uncertainty. The main advantage of constraint-based approaches is the possibility for human expert to model composite events with complex temporal constraints. But the approaches are usually deterministic and do not enable the convenient mechanism of probability reasoning to handle...
We propose a method for segmenting an arbitrary number of moving objects using the geometry of 6 points in 2D images to infer motion consistency. This geometry allows us to determine whether or not observations of 6 points over several frames are consistent with a rigid 3D motion. The matching between observations of the 6 points and an estimated model of their configuration in 3D space is quantified...
Various optical image stabilizers for reducing camera shake have been developed in many camera manufacturers, however, it has not been known exactly how effective they work for cancellation of the camera shake. We developed a novel system for analyzing behavior of camera shake and evaluating effectiveness of image stabilizers quantitatively. It consists of the custom-made LED display for generating...
Three-phase voltage-source inverter is one of the most widely used power converters. Therefore, the need to insure a continuous and safety operation for this power converter with fault detection technique is a need, more or less, depending on their application. For this power converter several faults can appear. This paper presents a method for the detection and identification of the transistor open...
A Digilog Book is an augmented reality (AR) based next generation publication supporting both sentimental analog emotions and immersive digital contents to improve a user's experience. This paper enhances the Digilog Book authoring tool, ARtalet. This is a tangible user interface based immersive AR authoring tool providing an intuitive non-programming based authoring methods using a 3D user interface...
Although SignWriting provides an intuitive notation system based on pictorial symbols to enable any sign based language in the world to be transcribed into a written form, it is a time consuming process for keyboard based input. To address the challenge of direct sign writing, the paper presents a human-computer-interaction system developed for recognition and visualisation of hand movements. The...
In this paper we propose a view invariant hand gesture recognition algorithm based on the assumption that the gesture trajectory is almost in a plane, which we call principal gesture plane. We use Least Squares Method to estimate the plane and project the 3D trajectory onto it. The viewpoint-dependent problem is solved by the projection. HMMs are chosen to model the gestures. We have evaluated the...
Understanding the dynamics of the individuals' daily mobility patterns is very important in a wide range of fields. However, lacking of tools to monitor the time-resolved location of individuals makes this research consume both tremendous time and money in the past. Nowadays, the rapidly developing ability to collect space-time activity (STA) data through new information technologies such as cellular...
The recognition of potentially hazardous situations on road intersections is an indispensable skill of future driver assistance systems. In this context, this study focuses on the task of vehicle tracking in combination with a long-term motion prediction (1-2 s into the future) in a dynamic scenario. A motion-attributed stereo point cloud obtained using computationally efficient feature-based methods...
Facing with in-flight damage/failure, Adaptive Flight Planer (AFP) should be activated to generate a new flight plan for pilots. To guarantee the solution is feasible, AFP requires knowledge of an aircraft's flight envelope. Therefore, AFP or the pilots should explore and exploit the known or unknown envelope to figure out the feasibility of the preferred final state and the appropriate transitions...
We present a procedure for egomotion estimation from visual input of a stereo pair of video cameras. The 3D egomotion problem, which has six degrees of freedom in general, is simplified to four dimensions and further decomposed to two two-dimensional subproblems. The decomposition allows us to use a voting strategy to identify the most probable solution, avoiding the random sampling (RANSAC) or other...
In this paper, an anti-swing control law, previously proposed for the 2-dimensional (2D, or planar) model of an overhead crane [2], is generalized to the 3-dimensional (3-D) case. The multi-input controller is based on the second-order sliding-mode approach. Thanks to specially designed sliding surfaces, explicitly depending on the load swing angles, zero steady position error and active load swing...
FDK reconstruction algorithm, owing to its relative easy implementation and highly computational efficiency, remains the most widely accepted method for 3D C-arm Cone-Beam reconstruction. Because of the inherence characteristic of FDK reconstruction algorithm, the reconstruction imaging has some shortcomings. The paper deals with the problems affecting the quality of 3D images reconstructed from projections...
Professional sport is a highly competitive field, and training tools are playing an increasingly important role. Recent improvements in sensor technology allow managers to monitor many new factors during training, but analyzing this data is time consuming, thus the need for specialized signal processing techniques. This paper presents our work on high level data extraction from tennis multi-view video...
The paper introduces a new air flow analysis approach based on Particle Tracking Velocimetry (PTV). One of the special features of the proposed method is that after the tracer particles are detected, matching and tracing are conducted jointly. To this end, we introduce an interpretation module based on a directed hypergraph for 3D curve reconstruction. At first the 2D inter-frame locations are localised...
Underwater testbeds are key tools for performance evaluation of underwater communication and coordination algorithms to enable swarming of autonomous vehicles. We describe a demonstration of underwater vehicle team formation and steering algorithms using our underwater testbed. The tesdbed allows the user to configure ocean currents and underwater communication parameters so to study properties of...
Solving geometrical problems on a set of 3D balls is a challenging task in computational geometry. They can be solved effectively when the Voronoi diagram for the set is available. The diagram is usually constructed by the edge-tracing or similar algorithms based on finding Voronoi vertices along edges. However, its expected quadratic time complexity makes it impractical. This can be improved significantly...
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