43,590 research outputs found
The Design of a System Architecture for Mobile Multimedia Computers
This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies
Numerical analysis of a fin-tube plate heat exchanger with winglets
In this presented work, numerical analysis of heat transfer and flow characteristic using
longitudinal vortex generators (LVGS) in fin and flat tube heat exchanger has been
presented. Conjugate heat transfer 3D numerical model has been developed and
successfully carried out. Rectangular winglets were set in pairs, with downstream
orientation. The effects of impact angles of (20â° , 30â°, and 40â° ) as well as tubes and
winglets were placed in one row lined arrangement and air flow by forward
arrangement and backward arrangement. Reynolds number is ranged from 500 to 5000.
The numerical results showed that in the range of the present study, the variation of
these parameters can result in the increase of heat transfer. The study focuses on the
Influence of the different parameters of VGs on heat transfer and fluid flow
characteristics of one row lined circular-tube banks. The characteristics of average Nu
number and skin friction coefficient are studied numerically by the aid of the
computational fluid dynamics (CFD) commercial code of FLUENT ANSYS 14. The
results showed increasing in the heat transfer and skin friction coefficient with the
increasing of Re number. It has been observed that the overall Nuav number of one
circular tubes increases by 23-31% ,by 23-43% and by 23-47% with angles of (20â°,
30°, and 40â°) respectively, in forward arrangement and the overall Nuav number of one
circular tubes increases by 23-42%, by 23-46% and 23-52%with angles of (20â°, 30°,
and 40â°) respectively, in backward arrangement, with increasing in the overall average
of skin friction coefficient. Also the results showed that the rectangular winglet pairs
(RWPs) can significantly improve the heat transfer performance of the fin and-tube
heat exchangers with a moderate pressure loss penalty
The 30/20 GHz fixed communications systems service demand assessment. Volume 3: Annex
A review of studies forecasting the communication market in the United States is given. The applicability of these forecasts to assessment of demand for the 30/20 GHz fixed communications system is analyzed. Costs for the 30/20 satellite trunking systems are presented and compared with the cost of terrestrial communications
CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines
Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective.
The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines.
From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research
Saving Energy in Mobile Devices for On-Demand Multimedia Streaming -- A Cross-Layer Approach
This paper proposes a novel energy-efficient multimedia delivery system
called EStreamer. First, we study the relationship between buffer size at the
client, burst-shaped TCP-based multimedia traffic, and energy consumption of
wireless network interfaces in smartphones. Based on the study, we design and
implement EStreamer for constant bit rate and rate-adaptive streaming.
EStreamer can improve battery lifetime by 3x, 1.5x and 2x while streaming over
Wi-Fi, 3G and 4G respectively.Comment: Accepted in ACM Transactions on Multimedia Computing, Communications
and Applications (ACM TOMCCAP), November 201
Semi-automatic semantic enrichment of raw sensor data
One of the more recent sources of large volumes of generated data is sensor devices, where dedicated sensing equipment is used to monitor events and happenings in a wide range of domains, including monitoring human biometrics. In recent trials to examine the effects that key moments in movies have on the human body, we fitted fitted with a number of biometric sensor devices and monitored them as they watched a range of dierent movies in groups. The purpose of these experiments was to examine the correlation between humans' highlights in movies as observed from biometric sensors, and highlights in the same movies as identified by our automatic movie analysis techniques. However,the problem with this type of experiment is that both the analysis of the video stream and the sensor data readings are not directly usable
in their raw form because of the sheer volume of low-level data values generated both from the sensors and from the movie analysis. This work describes the semi-automated enrichment of both video analysis and sensor data and the mechanism used to query the data in both centralised
environments, and in a peer-to-peer architecture when the number of sensor devices grows to large numbers. We present and validate a scalable means of semi-automating the semantic enrichment of sensor data, thereby providing a means of large-scale sensor management
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