Retrieval by content of 3D models is becoming more and more important due to the advancements in 3D hardware and software technologies for acquisition, authoring and display of 3D objects, their ...ever-increasing availability at affordable costs, and the establishments of open standards for 3D data interchange. In this paper, we present a new method, referred to as spin image signatures, that develops on the original spin images approach, with adaptations to support effective retrieval by content. According to the method proposed, a set of spin images is derived for each model, to obtain a view-independent description of its 3D shape and a signature is evaluated for each spin image in the set. Clustering is hence performed on the set of spin image signatures to obtain a compact representation. Experimental results are presented, showing the effectiveness of the spin image signatures method for retrieval, also in comparison with other methods, and its sensitivity to model deformations
Lithium ion (Li-ion) batteries exhibit high power and energy densities, as well as high-cycle-lifetime capabilities. Li-ion cells based on LiFePO 4 cathodes are promising alternatives to predominant ...metal oxide technologies, particularly for applications with high power and cycle lifetime requirements. This paper includes investigations on high-power LiFePO 4 cells' cycle lifetime. Therefore, 3000 full charge-discharge cycles are applied to the cells with high constant current rates. Through reference testing, increasing battery impedance and a fading capacity are identified as a consequence of battery aging. Capacity fade proceeds in a way that cells' open-circuit voltages (OCVs) change only in the range of high state-of-charge (SOC). A model-based method that can detect the decreasingly utilizable capacity is outlined. The proposed method considers the changing OCV characteristics and enables the determination of capacity loss without complete charge and discharge being necessary during battery operation. By the evaluation of capacity loss information, an accelerated battery aging or even possible battery damage caused by overcharge can be avoided during battery charging scenarios.
Automatic semantic annotation of video streams allows both to extract significant clips for production logging and to index video streams for posterity logging. Automatic annotation for production ...logging is particularly demanding, as it is applied to non-edited video streams and must rely only on visual information. Moreover, annotation must be computed in quasi real-time. In this paper, we present a system that performs automatic annotation of the principal highlights in soccer video, suited for both production and posterity logging. The knowledge of the soccer domain is encoded into a set of finite state machines, each of which models a specific highlight. Highlight detection exploits visual cues that are estimated from the video stream, and particularly, ball motion, the currently framed playfield zone, players’ positions and colors of players’ uniforms. The highlight models are checked against the current observations, using a model checking algorithm. The system has been developed within the EU ASSAVID project.
Image databases are widely exploited in a number of different contexts, ranging from history of art, through medicine, to education. Existing querying paradigms are based either on the usage of ...textual strings, for high-level semantic queries or on 2D visual examples for the expression of perceptual queries. Semantic queries require manual annotation of the database images. Instead, perceptual queries only require that image analysis is performed on the database images in order to extract salient perceptual features that are matched with those of the example. However, usage of 2D examples is generally inadequate as effective authoring of query images, attaining a realistic reproduction of complex scenes, needs manual editing and sketching ability. Investigation of new querying paradigms is therefore an important-yet still marginally investigated-factor for the success of content-based image retrieval. In this paper, a novel querying paradigm is presented which is based on usage of 3D interfaces exploiting navigation and editing of 3D virtual environments. Query images are obtained by taking a snapshot of the framed environment and by using the snapshot as an example to retrieve similar database images. A comparative analysis is carried out between the usage of 3D and 2D interfaces and their related query paradigms. This analysis develops on a user test on retrieval efficiency and effectiveness, as well as on an evaluation of users' satisfaction.
The ever increasing availability of 3D models demands for tools supporting their effective and efficient management. Among these tools, those enabling content-based retrieval play a key role. In this ...paper, we present a novel approach to global and local content-based retrieval of 3D objects that is based on spin images. Spin images are used to derive a view-independent description of both database and query objects. A set of spin images is first created for each object and the parts it is composed of; then, a descriptor is evaluated for each spin image in the set; clustering is performed on the set of image-based descriptors of each object to achieve a compact representation. Experimental results are presented for a test database of about 300 models, showing the effectiveness of retrieval for both object and part similarity.
In this paper we present CityDev, an interactive multi-agents simulation model of the development of a city. The model is based on agents, goods and markets. Each agent (family, industrial firm, ...developer, etc.) produces goods by using other goods, and trades the goods on the markets. Each good has a price, and the monetary aspects are included in the simulation. When agents produce goods and interact in the markets, the urban fabric is built and transformed. The computer model (simulator) runs on a 3-D spatial pattern organized in cubic cells. CityDev allows interactive users to get involved in the functioning of the model. In fact, they can manage agents generated by the simulator, as well as new agents created by themselves. Agents managed by users interact with agents managed by the simulator. In addition, an administration board interactively controls the development of the city trough the urban plan, the building of new roads and the location of public facilities. In the present paper the model is described and some results are shown.
Virtual Reality for Image Retrieval ASSFALG, J.; DEL BIMBO, A.; PALA, P.
Journal of visual languages and computing,
04/2000, Letnik:
11, Številka:
2
Journal Article
Recenzirano
Image database systems have been widely studied in the past years. Having to deal with visual information, a great effort has been put in designing and implementing user interfaces for the different ...retrieval engines. Most of the interfaces proposed so far allow the user to specify the query through visual examples, either by feeding a complete image to the system or by drawing some colour patches on a sketch-pad. However, formulating a query from scratch remains a hard task and users tend to use existing images as examples. Virtual reality provides realistic reproduction of natural environments along with a wide set of previously unexplored interaction techniques. We suggest to use non-immersive VR environments as the interface to perform query by content in a natural and effective way. Our non-immersive VR-based approach permits the user to navigate and edit a virtual environment and also to take photographs. These are then used to query a database of images based on their content. Relevance feedback interaction allows the user to extract parts of retrieved images and apply them back to the virtual environment from which a new photograph can be taken.
In the past decade, many automated prediction methods for the subcellular localization of proteins have been proposed, utilizing a wide range of principles and learning approaches. Based on an ...experimental evaluation of different methods and their theoretical properties, we propose to combine a well-balanced set of existing approaches to new, ensemble-based prediction methods. The experimental evaluation shows that our ensembles improve substantially over the underlying base methods.
In this paper we report on our experience in the detection and recognition of soccer highlights in videos using hidden Markov models. A first approach relies on camera motion only, whereas a second ...one also includes information regarding the location of players on the playing field. While the former approach requires less information, the latter has proven to be more precise. Our experimental evaluation yields interesting results.
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