15331077
Precoded V-BLAST for ISI MIMO channels
The V-BLAST (vertical Bell labs layered space-time) system is one of the MIMO systems designed to achieve a good multiplexing gain. In the recent literature, a V-BLAST precoder has been added in the transmitter which exploits channel information. This precoder forces each symbol stream to have identical MSE (mean square error). It can be viewed as an alternative to the bitloading method. In this paper, this precoded V-BLAST is extended to the case of ISI MIMO channels. Both the FIR and OFDM types of transceivers are derived
16174275
Bit rate optimized time-domain equalizers for DMT systems
The discrete multitone (DMT) transceivers have enjoyed great success in high speed data transmission. It is known that when the cyclic prefix is no shorter than the channel impulse response (CIR), the DMT system is ISI free. For channels with very long CIR such as DSL loops, a time-domain equalizer (TEQ) is typically added at the receiver to shorten the effective impulse response. This paper proposes a filterbank approach to the design of TEQ for maximizing the bit rate. Moreover we introduce the structure of a DMT system with multiple TEQs. The optimal solution for multiple TEQs is given in closed form and it can serve as a theoretical upper bound for all other TEQs. From the multiple TEQ structure, we propose a DMT system with a pair of complex conjugating TEQs. Simulation examples are given to verify the merit of the proposed TEQ.
41912438
Top Ten Problems in Visual Interfaces to Digital Libraries
Many research communities periodically and collectively deliberate about their most significant and challenging problems as a way to agree upon pressing questions and promising research directions. Identifying top-ten problems is a useful way to reflect on what a community has achieved and define a new research agenda for the future. This chapter introduces a set of such problems for research in visual interfaces of digital libraries in order to simulate studies in this area.
21308144
EmoEars: An Emotion Recognition System for Mandarin Speech
In this paper, an emotion recognition system for mandarin speech is presented. Five basic human emotions including angry, fear, happy, neutral and sad are investigated. The recognizer is based on neural network with OCON and ACON architecture. Some novel feature selection methods are also added as optional tool to enhance the efficiency and classification accuracy. The system can train speaker dependent emotion speech model through online emotional utterance recording. Experiment results show that emotion can be recognized through neural network model, the best mean accuracy is 86.7%. In addition, the feature selection module is effective to reduce the compute load and increase the generalization ability of the recognizer.
45097070
Spatial ability and visual navigation: an Empirical Study
Abstract In this paper, we describe an empirical study of individuals' spatial navigation strategies and a number of performance and preference measures with regard to the design of a novel 3D visualisation. The underlying semantic space of the user interface consists of a collection of papers from the three most recent ACM SIGCHI conference proceedings, visualised as a virtual reality network. This network was automatically constructed based on semantic similarities derived from latent semantic analysis. We studied die search strategies and general preferences of eleven subjects who used this system to find papers on various topics. The study has led to a number of interesting findings, which should be valuable for designers and evaluators of 3D user interfaces. The results highlight the importance of structural elements in the design of a semantically based user interface, because search strategies of users relied heavily on these mechanisms in the design. The results of this study also demonstrate that...
12972622
DIKNN: An Itinerary-based KNN Query Processing Algorithm for Mobile Sensor Networks
Current approaches to k nearest neighbor (KNN) search in mobile sensor networks require certain kind of indexing support. This index could be either a centralized spatial index or an in-network data structure that is distributed over the sensor nodes. Creation and maintenance of these index structures, to reflect the network dynamics due to sensor node mobility, may result in long query response time and low battery efficiency, thus limiting their practical use. In this paper, we propose a maintenance-free, itinerary-based approach called density-aware itinerary KNN query processing (DIKNN). The DIKNN divides the search area into multiple cone-shape areas centered at the query point. It then performs a query dissemination and response collection itinerary in each of the cone-shape areas in parallel. The design of the DIKNN scheme also takes into account challenging issues such as the the dynamic adjustment of the search radius (in terms of number of hops) according to spatial irregularity or mobility of sensor nodes. The simulation results show that DIKNN yields substantially better performance and scalability over previous work, both as k increases and as the sensor node mobility increases. It outperforms the second runner with up to 50% saving in energy consumption and up to 40% reduction in query response time, while rendering the same level of query result accuracy.
21349955
A unified optimization framework for microelectronics industry
In this paper, an object-oriented unified optimization framework (UOF) for general problem optimization is proposed. Based on evolutionary algorithms, numerical deterministic methods, and C++ objective design, the UOF possesses real-world applications for various optimization problems. The UOF is with interface between defining a general problem and generic solver; hence the two areas are bridged. The UOF's components are categorized into problem and solver parts, and they work independently. Therefore, the reusable high level code allows the adaptation to new problem and solver quickly. Practical applications in microelectronics industry confirm the functionality of the developed unified optimization framework.