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A novel model of the path loss and power delay profile in a meeting room scenario is proposed. The parameters of the model are estimated from extensive measurements of a wireless channel under Line-Of-Sight conditions at 2.6 GHz. The model is improved by using reverberation theory to characterize relevant properties of primary and reverberant components varying with distance. Furthermore, the model...
While there were high hopes for multihop wireless networks (mesh) to provide ubiquitous WiFi in many cities, in-field trials revealed the node spacing required for WiFi propagation induced a prohibitive cost model for network carriers to deploy. However, the digitization of TV channels and new FCC regulations have reapportioned spectrum for data networks with far greater range than WiFi due to lower...
Environmental factors that lead to the movement and type of obstacles in and around wireless links are well-known to directly affect channel characteristics. However, while mobile users typically have repeatable daily or weekly patterns with common locations being frequently visited, many protocols along the network stack do not attempt to identify when physical locations are revisited. If wireless...
Cellular networks have addressed the multi-fold increase in traffic demand through various approaches from increasingly smaller cells to offloading demand to unlicensed spectrum, such as WiFi and TV white spaces. The latter approach has a tremendous cost benefit as unlicensed hardware can be co-located with existing cellular infrastructure. However, in these situations where demand is the greatest,...
Adult image detection is an important technology for Internet pornographic information filtering. However, the conventional methods, such as analyzing skin-like or global features, suffer from the high false positive rate. Based on the Bag-of-Words model, a new adult image detection method combined with skin visual words and face information is proposed. Firstly, a skin color detection algorithm based...
In anticipation of the increasing demand of wireless traffic, WiFi standardization efforts have recently focused on two key technologies for capacity improvement: multi-user MIMO and wider bandwidth. However, users experience heterogeneous channel orthogonality characteristics across sub-carriers in the same channel bandwidth, which prevents ideal multi-user gain. Moreover, frequency selectivity increases...
While many metropolitan areas sought to deploy city-wide WiFi networks, the densest urban areas were not able to broadly leverage the technology for large-scale Internet access. Ultimately, the small spatial separation required for effective 802.11 links in these areas resulted in prohibitively large up-front costs. The FCC has reapportioned spectrum from TV white spaces for the purposes of large-scale...
Vehicular wireless channels have a high degree of variability, presenting a challenge for vehicles and infrastructure to remain connected. The emergence of the white space bands for data usage enables increased flexibility for vehicular networks with distinct propagation characteristics across frequency bands from 450 MHz to 6 GHz. Since wireless propagation largely depends on the environment in operation,...
The application of machine learning algorithms in wireless communications has attracted increasing attention due to the promising performance gains recently achieved. Static classification algorithms have been successfully applied to training protocols that adapt transmission parameters according to context information. However, in reality, there are many time-varying reasons for fading channel quality...
Context awareness has received increasing attention with the proliferation of various types of sensors on mobile devices. However, while wireless performance is known to be highly correlated with environmental settings, mobile devices have yet to fully exploit the awareness of context to improve wireless performance. In this paper, we leverage available context information to improve link-level adaptation...
Multidisciplinary models of complex products are developed by heterogeneous CAE tools in a distributed simulation environment. It is a key technology to integrate CAE models together, making them work collaboratively. In this paper, a modular method is proposed. First, a stage-by-stage modeling method is presented to reduce the interaction between modeling and simulation. Then, HLA and web service...
Multidisciplinary modeling and simulation of complex engineering systems are generally realized by an integrated approach in which the global system is decomposed into some coupling models of subsystems and then for collaborative computation. However, the coupling relationship of design variables between different disciplinary models usually increases the complexity of collaborative computation. It...
Increasingly stringent Extended Producer Responsibility (EPR) legislations all over the world are making the consideration of End-of-Life vehicles (ELVs) treatment a priority for the vehicle producers, and they are required to reduce the environment pollution and improve the recycling/recovery rate of their ELVs. It is urgent for the producers to establish an efficient green supply chain management...
Recycling of Automotive products is an effective strategy and a necessary choice for promoting sustainability in the automotive industry. The recycling information, such as end-of-life (EoL) information, dismantling information, material information, disposal information of toxic and harmful substances and residual life information, etc, are important for the producers, dismantlers and government,...
Collaborative simulation is an important technology for complex engineering systems. The challenges of collaborative simulation are especially in model integration, interaction control and time advancement where a variety of collaborative disciplinary subsystems for time-synchronized running are handled dynamically in a distributed environment. In this paper, the formulized paradigm of multidisciplinary...
In the future, Synthetic Aperture Radar (SAR) requires enhanced capabilities, such as all-weather and better resolving power, more widely used in sciences, etc. New system to improve the control and monitor capability is desired by the development of the carrying-platform and SAR itself. A fast and small control and monitor system has been developed and tested. It employs SOPC (System On Programmable...
Remanufacturing is a necessary choice in order to develop a circular economy of the automotive industry. The key question is how to improve the system reliability of remanufactured products. First, this paper points out the reliability requirements of remanufactured systems. Then it analyzes systematically the similarities and differences between the manufacturing, remanufacturing and repairing process...
Tools selection that is made artificially in manufacturing process often takes the experts much time and such experience is difficult to be shared. In this overview, the general tools selection process is summarized, and the methodologies, including based-rules method and other preventative algorithms, are introduced according to their applicable conditions. A practical intelligent system and a multi-hierarchy...
With the rapid development of automobile electronics level, the mechatronics of automobile product becomes more and more obviously. When we try our best to improve function of automobile by electronic controlled system, the difficulty of failure diagnosis is increasing too. In order to improve the maintenance quality and efficiency, automobile manufacturer and maintenance server have established the...
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