Abstract—In the future communication applications, users may obtain their messages that have different importance levels distributively from several available sources, such as distributed storage or even devices belonging to other users. This scenario is the best modeled by the multilevel diversity coding systems (MDCS). To achieve perfect (information-theoretic) secrecy against wiretap channels, this paper investigates the fundamental limits on the secure rate region of the asymmetric MDCS (AMDCS), which include the symmetric case as a special case. Threshold perfect secrecy is added to the AMDCS model. The eavesdropper may have access to any one but not more than one subset of the channels but know nothing about the sources, as long as the size of the subset is not above the security level. The question of whether superposition (source separation) coding is optimal for such an AMDCS with threshold perfect secrecy is answered. A class of secure AMDCS (S-AMDCS) with an arbitrary number of encoders is solved, and it is shown that linear codes are optimal for this class of instances. However, in contrast with the secure symmetric MDCS, superposition is shown to be not optimal for S-AMDCS in general. In addition, necessary conditions on the existence of a secrecy key are determined as a design guideline.
标签： Fundamental Limits Secure Class on of
上传时间： 2020-01-04
上传用户：kddlas
Mobile wireless communications are in constant evolution due to the continu- ously increasing requirements and expectations of both users and operators. Mass multimedia* services have been for a long time expected to generate a large amount of data traffic in future wireless networks [1]. Mass multimedia services are, by definition, purposed for many people. In general, it can be distinguished between the distribution of any popular content over a wide area and the distribu- tion of location-dependent information in highly populated areas. Representative examples include the delivery of live video streaming content (like sports compe- titions, concerts, or news) and file download (multimedia clips, digital newspa- pers, or software updates).
标签： Broadcasting Generation Mobile Next
上传时间： 2020-05-31
上传用户：shancjb
Thanks to the advances in micromachining fabrication technologies and significant cost reduction due to mass production, miniature sensors of angular rate, or gyroscopes, found their way into the everyday life of every user of modern gadgets, such as smart phones, tablets or even wristwatches. Often without realising, many of us are carrying in our pockets fully equipped with all necessary sensors complete inertial navigation systems that not so long ago were available only for advanced vehicles in sea, land, air or space. Accelerometers and gyroscopes are found in specifications of any gadget supposed to react to user movements. And one of the most commonly used type of gyroscopes used to developed these systems is Coriolis vibratory gyroscope (CVG).
标签： Gyroscopes Vibratory Coriolis
上传时间： 2020-06-06
上传用户：shancjb
Nowadays sensors are part of everyday life in a wide variety of fields: scientific applications, medical instrumentation, industrial field, ...and, last but not least, popular mass production and low-cost goods, like smartphones and other mobile devices. Markets and business behind the field of sensors are quite impressive. A common trend for consumer applications is miniaturization which requires, on one side, a lot of research, development efforts, and resources but, on the other hand, allows costs and final application size reduction. In this scenario scientific community and industries are very active to drive innovation.
标签： Magnetometers Lorentz Force MEMS
上传时间： 2020-06-06
上传用户：shancjb
Electricity has been chosen as the most convenient and useful form of energy, due to its ease of transportation over large distances and easy conversion to other energy forms. The biggest inconvenience with electricity is that it cannot be stored and must be utilized at the moment of generation. The storage of a large amount of electrical energy is usually connected with its conversion to other types of energy, which significantly reduces the efficiency of such processes. The aim of the power system, often treated as the biggest and the most complex machine ever built, is to deliver uninterruptible electric energy of demanded quality parameters to consumers.
标签： Electromagnetic Interference Conducted
上传时间： 2020-06-07
上传用户：shancjb
The author of this textbook intends to consider all stages of the life cycle of the energy resources: extraction of mineral energy resources and mastering for power engineering renewable energy, transportation of mineral energy raw materials to the place of consumption, the conversion of primary energy sources into electrical and/or thermal energy, transportation and distribution among the customers, and energy storage (if necessary).
标签： Engineering Electrical Current Power State
上传时间： 2020-06-07
上传用户：shancjb
A revolution in power industries, including generation, transmission and distribution, driven by environmental and economic considerations, is taking place all over the world. The smart grid allows for integration of diverse generation and storage options, reduced losses, improved efficiencies, increased grid flexibility, reduced power outages, allowing for competitive electricity pricing and integration of electric vehicles and overall becoming more responsive to market, consumer and societal needs. It is bringing profound changes to both power systems and many related industries.
标签： Measurement Innovative Solutions Testing and
上传时间： 2020-06-07
上传用户：shancjb
A modern power grid needs to become smarter in order to provide an affordable, reliable, and sustainable supply of electricity. For these reasons, a smart grid is necessary to manage and control the increasingly complex future grid. Certain smart grid elements including renewable energy, storage, microgrid, consumer choice, and smart appliances like electric vehicles increase uncertainty in both supply and demand of electric power.
标签： Intelligent Management Microgrid
上传时间： 2020-06-07
上传用户：shancjb
Battery systems for energy storage are among the most relevant technologies of the 21 st century. They – in particular modern lithium-ion batteries (LIB) – are enablers for the market success of electric vehicles (EV) as well as for stationary energy storage solutions for balancing fluctuations in electricity grids resulting from the integrationofrenewableenergysourceswithvolatilesupply 1 .BothEVandstationary storage solutions are important because they foster the transition from the usage of fossil energy carriers towards cleaner renewable energy sources. Furthermore, EV cause less local air pollution and noise emissions compared to conventional combustion engine vehicles resulting in better air quality especially in urban areas. Unfortunately, to this day, various technological and economic challenges impede a broad application of batteries for EV as well as for large scale energy storage and load leveling in electricity grids.
标签： Multiscale Simulation Approach
上传时间： 2020-06-07
上传用户：shancjb
Plug in Electric Vehicles (PEVs) use energy storages usually in the form of battery banks that are designed to be recharged using utility grid power. One category of PEVs are Electric Vehicles (EVs) without an Internal-Combustion (IC) engine where the energy stored in the battery bank is the only source of power to drive the vehicle. These are also referred as Battery Electric Vehicles (BEVs). The second category of PEVs, which is more commercialized than the EVs, is Plug in Hybrid Electric Vehicles (PHEVs) where the role of the energy storage is to supplement the power produced by the IC engine.
上传时间： 2020-06-07
上传用户：shancjb
