Catálogo de publicaciones - libros

GIS can only be applied to certain areas by storing format, and it is subordinate to a system when displaying geographic information data. It is therefore inevitable for GIS to use GML that supports efficient usage of various geographic information data and interoperability for integration and sharing. The paper constructs VisualGML that translates currently-used geographic information such as DXF(Drawing Exchange Format), DWG(DraWinG), or SHP(Shapefile) into GML format to visualize. In order to provide a flexibility of a mobile device, VisualGML constructs integrated map preprocess module which filters geographic information data according to its tag and properties. VisualGML also provides two major GIS services for user and administrator, it can be enable visualizing location search this is applied with 3-Layer POI structure for user. For administrator, it has trace monitoring visualization through moving information of mobile devices.

A novel approach to speaker recognition in mobile or IP network environment is described. In this approach, we use decoded line spectral frequency (LSF) parameters directly from compressed speech packets instead of using parameters from decompression and analysis procedure. Furthermore, we reduce the number of LSF series based on a restricted temporal decomposition method. Consequently, proposed approach gets more than three times faster than a traditional speaker recognition approach without losing any accuracy according to our experiments.

In this paper, we introduce a non-voice rejection method to perform Voice/Non-Voice (V/NV) classification using a fundamental frequency (F0) estimator called YIN. Although current speech recognition technology has achieved high performance, it is insufficient for some applications where high reliability is required, such as voice control of powered wheelchairs for disabled persons. The V/NV classification algorithm, which rejects non-voice input in Voice Activity Detection (VAD), is helpful for realizing a highly reliable system. The proposed V/NV classification adopts the ratio of a reliable F _0 contour to the whole input interval. To evaluate the performance of our proposed method, we used 1567 voice commands and 447 noises in powered wheelchair control in a real environment. These results indicate that the recall rate is 97% when the lowest threshold is selected for noise classification with 99% precision in VAD.

The Digital Multimedia Broadcasting (DMB) system was developed to provide high-quality multimedia contents in the mobile environment. The system adopts the MPEG-4 standard for its main video, audio and other media formats. It also adopts MPEG-4 scene description for its interactive multimedia contents. Its animated and interactive contents are based on BIFS (Binary Format for Scenes), which refers to the spatio-temporal specifications and behavior of the individual objects. The more interactive contents are, the more high-bitrate the scene description should be. However, the bandwidth for allocating meta-data such as those in scene descriptions is restrictive in the mobile environment. On one hand, the DMB terminal starts demultiplexing contents and decoding individual media with its own decoder. After decoding each medium, the rendering module presents each media stream according to the scene description. Thus, the BIFS stream corresponding to the scene description should be decoded and parsed before the audio or visual object is presented. For these reasons, the transmission delay of the BIFS stream causes the delay in the entire audio-visual scene presentation, although the audio or video streams are en-coded in very low bitrate. This paper presents the effective optimization technique for adapting the BIFS stream into an expected MPEG-2 TS bitrate with-out bandwidth waste and for avoiding delay in the transmission of the initial scene description for interactive DMB contents.

Wearable computer can be worn anytime with the support of unrestricted communications and variety of services which provides maximum capability of information use. Key challenges in developing such wearable computers are level of comfort that users do not feel what they wear, easy and intuitive user interface and power management technique. This paper suggests a wearable system that consists of a wristwatch-type gesture recognition device and a personal mobile gateway that functional input/output modules can be freely plugged in and taken out. We describe our techniques implemented during our wearable system development: 1) multimodal fusion engine that recognizes voice and gesture simultaneously, 2) power management technique and 3) gesture recognition engine. Finally, we evaluate the performance of our multimodal fusion engine, and show the power consumption measurement data of our system built with the power management technique.

Recently directional sensors have been widely deployed as they are more practicable under constraints of manufacture, size and cost. One common functionality of networks formed by such directional sensors is to monitor a set of discrete targets continuously. Large scale deployment makes sensor recharge impossible. By abundant deployment, it is reasonable and necessary to select subsets of sensors to operate alternatively so as to prolong the network lifetime. Such problem has been proved to be NP-Complete. This paper approximates network lifetime problem by randomized algorithm. Through constructing elementary sessions , which denotes active subset of sensors covering all targets, and linear programming, the approximating solution is derived within extremely less duration comparing to previous works. Simulation results demonstrate the algorithm’s performance and sound explanation is also presented.

In this paper we introduce a novel system that comprises techniques advancing the query processing in wireless sensor networks. Our system facilitates time triggered queries that are scheduled in a distributed fashion among sensor nodes. Thus, time synchronisation is of paramount importance. Since accurate time synchronisation requires more energy, our system allows a trade off between precision of time and energy according to the user requirements. To minimize the communication overhead for query processing, our system employs new query execution mechanisms. We have implemented our query processing system on Sun^TM Small Programmable Object Technology (SPOT) sensor network platform. The system was entirely programmed in Java enabling an object oriented design and implementation. It provides a friendly graphical user interface for query management and visualisation of results.

Geographic routing protocols on Wireless Sensor Network (WSN) had been researched for many years, but they did not concern with the fault problem. In this paper, we propose an approach to enhance dependability of existing geographical routing protocols to deal with the fault problem and consider the routing problem based on the fault map via query-driven models. For query-driven model, a novel algorithm, called Relay Node Selection Algorithm (RNSA) is proposed, which selects a few relay nodes as temporary destinations. Simulation shows that the success rate of data transmission originated from base station can be raised substantially and the hop count is also reduced via the selected relay nodes.

Density control is a promising method to conserve system energy and prolonging lifetime of wireless sensor networks. In this paper, we address the issue of maintaining sensing coverage of surveillance target in large density wireless sensor networks and present an efficient technique for the selection of active sensor nodes. First, the At Most k-Coverage Problem (AM k-Coverage) is defined and modeled as a nonlinear integer programming. Second, Genetic Algorithm which is a quasi-parallel method to construct set cover is designed to solve the multi-objective nonlinear integer programming. And later by using Genetic Algorithm, a central algorithm is designed to organize a sensor network into coverage sets. Finally, Experimental results show that the proposed algorithm can construct the coverage sets reliably and reduce the number of active sensor nodes which is helpful to reduce system energy consumption and prolong the network lifespan.

In this paper, a multi-way way prediction policy (MWWP) with a two-port Way Predictor (TPWP) is proposed for reducing the dynamic and leakage energy in multi-way set associative drowsy I-Cache without dramatic loss of performance. One port of TPWP is used for predicting the matching way in current set, only the predicted way and not all the ways is accessed to reduce the dynamic energy. The other is used for predicting the matching way in subsequent set, only the cache line in predicted way is pre-woken up from the drowsy mode to reduce the leakage energy. Different with the traditional way prediction policy, the MWWP has the lower performance overhead by selecting multiple ways speculatively for each access to improve way prediction hit ratio (WPHR). The simulation and estimation results show that, in a 4-way set-associative drowsy I-Cache, with 0.98% and 0.4% performance overhead respectively, our proposed 2-way and 3-way way prediction policy with TPWP can reduce 59% and 47% of energy in I-Cache, and save the 6.1% and 5.4% of the whole processor energy. The EDP is improved by 4.5% and 4.1% on average.