Optimal Scheduling of Secondary Content for Aggregation in Video-on-Demand Systems

Dynamic service aggregation techniques can exploit skewed access popularity patterns to reduce the costs of building interactive VoD systems. These schemes seek to cluster and merge users into single streams by bridging the temporal skew between them, thus improving server and network utilization. Rate adaptation and secondary content insertion are two such schemes. In this paper, we present and evaluate an optimal scheduling algorithm for inserting secondary content in this scenario. The algorithm runs in polynomial time, and is optimal with respect to the total bandwidth usage over the merging interval. We present constraints on content insertion which make the overall QoS of the delivered stream acceptable, and show how our algorithm can satisfy these constraints. We report simulation results which quantify the excellent gains due to content insertion. We discuss dynamic scenarios with user arrivals and interactions, and show that content insertion reduces the channel bandwidth requirement to almost half. We also discuss differentiated service techniques, such as N-VoD and premium no-advertisement service, and show how our algorithm can support these as well.

In Memoriam Benjamin Thomas Hoyt

Memoriam.

The African slave trade / by Thomas Fowell Buxton.

Digitized by Google

The law and custom of slavery in British India : in a series of letters to Thomas Fowell Buxton, Esq. by William Adam; Thomas Fowell Buxton, Sir

http://books.google.com/books?id=plhkPFrJ1QUC&dq=law+and+custom+of+slavery+in+British+India

Up and down the north Pacific coast by canoe and mission ship / by Rev. Thomas Crosby, missionary to the Indians of British Columbia.

http://www.archive.org/details/upanddownnorth00crosrich

The life of John Brainerd, the brother of David Brainerd, and his successor as missionary to the Indians of New Jersey ... By Rev. Thomas Brainerd.

http://name.umdl.umich.edu/ABB4262

Missionary survey as an aid to intelligent co-operation in foreign missions, by Roland Allen, and Thomas Cochrane.

http://www.archive.org/details/missionarysurvey13360gut

Missions the chief end of the Christian Church; also, the qualifications, duties, and trials, of an Indian Missionary: being the substance of services held on the 7th March, in St. Andrew's Church, Edinburgh, at the ordination of the Rev. Thomas Smith.

http://books.google.com/books?vid=OCLC55772204

The clear sunshine of the gospel breaking forth upon the Indians in New-England / by Thomas Shepard.

http://www.archive.org/details/clearsunshineofg00sheprich

Asian Christology and the Mahayana : a reprint of the century-old "Indian Church History", by Thomas Yeates ; and the further investigation of the religion of the Orient as influenced by the Apostle of the Hindus and Chinese

http://www.archive.org/details/asianchristology00gorduoft

Nutrition or Detoxification: Why Bats Visit Mineral Licks of the Amazonian Rainforest

Many animals in the tropics of Africa, Asia and South America regularly visit so-called salt or mineral licks to consume clay or drink clay-saturated water. Whether this behavior is used to supplement diets with locally limited nutrients or to buffer the effects of toxic secondary plant compounds remains unclear. In the Amazonian rainforest, pregnant and lactating bats are frequently observed and captured at mineral licks. We measured the nitrogen isotope ratio in wing tissue of omnivorous short-tailed fruit bats, Carollia perspicillata, and in an obligate fruit-eating bat, Artibeus obscurus, captured at mineral licks and at control sites in the rainforest. Carollia perspicillata with a plant-dominated diet were more often captured at mineral licks than individuals with an insect-dominated diet, although insects were more mineral depleted than fruits. In contrast, nitrogen isotope ratios of A. obscurus did not differ between individuals captured at mineral lick versus control sites. We conclude that pregnant and lactating fruit-eating bats do not visit mineral licks principally for minerals, but instead to buffer the effects of secondary plant compounds that they ingest in large quantities during periods of high energy demand. These findings have potential implications for the role of mineral licks for mammals in general, including humans.

Demand-based Document Dissemination for the World-Wide Web

We analyzed the logs of our departmental HTTP server http://cs-www.bu.edu as well as the logs of the more popular Rolling Stones HTTP server http://www.stones.com. These servers have very different purposes; the former caters primarily to local clients, whereas the latter caters exclusively to remote clients all over the world. In both cases, our analysis showed that remote HTTP accesses were confined to a very small subset of documents. Using a validated analytical model of server popularity and file access profiles, we show that by disseminating the most popular documents on servers (proxies) closer to the clients, network traffic could be reduced considerably, while server loads are balanced. We argue that this process could be generalized so as to provide for an automated demand-based duplication of documents. We believe that such server-based information dissemination protocols will be more effective at reducing both network bandwidth and document retrieval times than client-based caching protocols [2].