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1.
Wireless Personal Communications - The ongoing technological developments have totally transformed the lives of human beings. With the emergence of the smart era and the smart city concept, a few...  相似文献   
2.
The interaction between multiple incompressible air jets has been studied numerically and experimentally. The numerical predictions have been first validated using experimental data for a single jet configuration. The spreading features of five unequal jets in the configuration of one larger central jet surrounded by four smaller equi‐distant jets, have been studied, for different lateral spacing ratios of 1.5, 2.0 and 2.5 and a central jet Reynolds number of 1.24×105 (corresponding to a Mach number of 0.16). Flow of five equal jets has also been simulated, for the sake of comparison. The jet interactions commence at an axial distance of about 3–4 diameters and complete by an axial distance of about 10 diameters for the lowest spacing ratio of 1.5. For larger spacing ratios, the length required for the start and completion of jet interaction increase. Peripheral jets bend more towards the central jet and merge at a smaller distance, when their sizes are smaller than that of the central jet. The entrainment ratio for multiple jets is higher than that for a single jet. Excellent agreement is observed between the experimental data and theoretical predictions for both mean flow field and turbulent quantities, at regions away from the jet inlet. The potential core length and initial jet development, however, are not predicted very accurately due to differences in the assumed and actual velocity profiles at the jet inlet. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
3.
eWALL framework, under development in the European eWALL project (project no. 610658: “eWALL for Active Long Living”) is meant for care of population with age related impairments, mild dementia and COPD. Expanded eWALL (e2WALL) is planned to be an integrated quality framework for long-term care services which will cover very different types of care: all healthcare (both preventive and rehabilitative), societal services, care for cognitive diseases, services delivered at home as well as support for caregivers as an integral part of the quality improvement process. Thus, we present e2WALL home system that would encompass installation (setup) of e2WALL in homes (flats, houses and aging homes) and their management and maintenance across Europe, starting from the partners involved in eWALL (Austria, Bulgaria, Croatia, Denmark, Former Yugoslav Republic of Macedonia, Germany, Greece, Italy, Montenegro, The Netherlands and Romania) and expanding the partnership to the most of Europe (e.g. United Kingdom, Poland, Czech Republic…). This would be a direct application of the developed e2WALL platform and should be done through a network of collaborating small-to-medium sized enterprises (SMEs), each of whom would lead the process of setting up e2WALL system and continuing to provide support services to homes in their respective country. In this way, the growth of high tech and innovative SMEs will be ensured at pan European level, which will enable growth over restricted national market and stimulate European investments in SMEs and startups. Actually, the bigger platform will enable e2WALL European Ecosystem (e4WALL), which can then expand into other non-European markets (e.g. Asia, USA) and means sustainability beyond the life of the project. e2WALL will lead to connected tech start-up hubs to the larger European business ecosystem and will contribute to increased access of country-specific and customized new product to the pan European market, which will lead to increase of employed qualified individuals. Another important focus would be creating an energy efficient environment for a new social network where registered users would provide on-demand services.  相似文献   
4.
Wireless Personal Communications - Internet of things (IoTs) has been the smartest technology proven worldwide these days. The application products of IoTs are Mobile ad hoc network (MANET) and...  相似文献   
5.
Wireless Personal Communications - A Wireless Mesh Network (WMN) is a multi-hop network that gains the benefits of low deployment cost, fast access speed, expanded service coverage and large...  相似文献   
6.
Wireless networks are characterized by simple end devices and limited bandwidth. One solution to address these and other limitations of the wireless mobile environment that has been widely pursued is the placement of proxies, or agents, inside the network to assist with application processing that would normally take place on end devices. These agents can additionally manipulate data to reduce bandwidth requirements and assist in providing services. The design and implementation of a user agent is heavily impacted by the application it supports. In this paper we present our experiences with user agents in two different types of applications: telephony-based Personal Communication Services (PCS) and two-way messaging. To provide low latency service, the PCS user agents are mobile so that they may be kept close to their end devices. The design of the PCS agents limits migration overhead to the transfer of approximately 100 bytes of information in about 150 milliseconds. To provide advanced messaging services, the messaging user agent supports flexible messages while limiting air interface bandwidth usage. The messaging agents reduce uplink bandwidth usage by approximately 35% when applied to a cellular PCS system, and reduce message payloads by 97%. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
7.
Third-generation mobile radio networks, often dubbed as 3G, have been under intense research and discussion recently and will emerge around the year 2000. In the International Telecommunications Union (ITU), third generation networks are called International Mobile Telecommunications-2000 (IMT-2000), and in Europe, Universal Mobile Telecommunications System (UMTS). IMT-2000 will provide a multitude of services, especially multimedia and high-bit-rate packet data. Wideband code division multiple access (CDMA) has emerged as the mainstream air interface solution for the third-generation networks. In Europe, Japan, Korea, and the United States, wideband CDMA systems are currently being standarized. This article provides a comprehensive introduction to wideband CDMA. It also provides a review of the wideband CDMA air interface proposals including WCDMA in Europe and Japan, cdma2000 in the United States, and wideband CDMA in Korea.  相似文献   
8.
Wireless Personal Communications -  相似文献   
9.
With the advent of high efficacy light emitting diode directional lamps as a key component in focal lighting, new possibilities emerge for re-designing the smart home scenario. A smart home scenario is characterized by enabled intelligent interworking of various wireless and wired technologies to provide inhabitants with ease of use of appliances, while creating a personalized and safe ambience space. More and more high and low data rate circulates within the indoor ambient space (e.g., home, hospitals, offices). Although, unlicensed technologies, such as wireless local area networks can take upon part of the indoor traffic, the ever increasing demand for such data, and users, calls for either use of licensed or novel unlicensed wireless communication technologies as part of the smart home enablers. This paper focuses on the potentials of visible light communications (VLCs), jointly with radio and fiber communications, to support very dense low and high data rate connectivity, while enabling deployment of secure-sensitive indoor applications, including indoor tracking and localization. The paper proposes a scenario for integrating VLC into the smart home scenario and a conceptual supporting architecture for its deployment. Further, the technical challenges and possible roadmap for the actual deployment are analyzed for the particular case of an eHealth scenario where the utilization of VLC technology is the enabler of the cost-efficient rollout of the required infrastructure and thus the game-changer in a multi-billion eHealth niche that is seeking for cost affordable solutions.  相似文献   
10.
In the wake of a rectangular cylinder measurements of mean velocity and some turbulent stresses are carried out in a straight duct and in a curved duct. The difference in turbulent quantities in the wake of the body, in the straight duct an in the curved duct is significant especially in the downstream side of the wake. The shear stresses are more sensitive to curvature than the normal stresses.  相似文献   
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