We study fast data collection in linear duty-cycled wireless sensor networks (WSNs). We first present a benchmark algorithm that can achieve optimality in a general case (i.e., in non-duty-cycled case). Then, based on the insights obtained in the general case, we propose an optimal algorithm and a distributed algorithm for the case when each sensor only works at one slot in a cycle in duty-cycl...

Mobile networks pose new issues in the field of distributed garbage collection. Garbage collection must deal with volatile connections that may break remote object references unexpectedly for an unpredictable amount of time. As a result, no automatic distributed garbage collection satisfies the new hardware phenomena. A semantic-based approach called semi-automatic garbage collection is propose...

Wireless sensor networks (WSNs) are used to collect various data in environment monitoring applications. The most comprehensive way of data collection is to make every sensor node report periodically its sensing data to a base node. To reduce the energy consumption due to excessive communication, the network is partitioned into a set of spatial clusters with similar sensing data. For each clust...

Future mobile networks will be increasingly heterogeneous. Already today, wireless LAN is used by many mobile network operators as an addition to traditional technologies like GSM and UMTS; WiMax and 3GPP Long Term Evolution (LTE) will be added. Having heterogeneous wireless networks, one challenging research question needs to be answered: Which user should be served by which access network and...

This paper studies the problem of data gathering in multi-hop wireless ad hoc networks. In this scenario, a set of wireless devices constantly sample their surroundings and initiate report messages addressed to the base station. The messages are forwarded in a multi-hop fashion, where the wireless devices act both as senders and relays. We consider data gathering without aggregation, i.e. the n...

One of the most important applications for wireless sensor networks (WSNs) is Data Collection, where sensing data are collected at sensor nodes and forwarded to a central base station for further processing. Since using battery powers and wireless communications, sensor nodes can be very small and easily attached at specified locations without disturbing surrounding environments. This makes WSN...

The paper describes how to use inference networks to solve two problems in searching multiple collections: collection selection and result merging. The eeectiveness of the approaches is demonstrated with the INQUERY system and 3 gigabyte TREC collections.

in recent years, many researchers have been done in the area of wireless sensornetworks that has led to the variety of algorithms and methods for the collection andtransmission of environment information; but still many challenges faced bywireless sensor networks using methodologies are applied in various fields. such asmedia access control that due to the media being shared on these networks, ...

Cities are hubs of human activity; the everyday actions of myriad households, businesses, and industries located within a city’s geopolitical boundary. Measuring greenhouse gas (GHG) emissions associated with cities is confounded by the relatively small spatial scale of cities compared with the large-scale engineered infrastructures in which they are embedded; that is, the electricity grid, tra...

This research involves the design and analysis of pinch-based water/wastewater networks to minimize water utility in the petrochemical and petroleum industries. A study has been done on Tehran Oil Refinery to analyze feasibilities of regeneration, reuse and recycling of water network. COD is considered as a single key contaminant. Amount of freshwater was reduced about 149m/h (43.8%) regarding ...