Towards Scalable and Affordable Content Distribution Services

peer reviewe

Real-Time HDR Panorama Video

The interest for wide field of view panorama video is in-creasing. In this respect, we have an application that uses an array of cameras that overlook a soccer stadium. The input of these cameras are stitched together to provide a panoramic view of the stadium. One of the challenges we face is that large parts of the field are obscured by shad-ows on sunny days. Such circumstances cause unsatisfying video quality. We have therefore implemented and evaluated multiple algorithms related to high dynamic range (HDR) video. The evaluation shows that a combination of several approaches gives the most useful results in our scenario

Group communication techniques in overlay networks

One type of Internet services that have recently gained much attention are services that enable people around the world to communicate in real-time. Such services of real-time interaction are offered by applications most commonly referred to as distributed interactive applications. Concrete examples of distributed interactive applications are multiplayer online games, audio/video conferencing, and many virtual-reality applications linked to education, entertainment, military, etc. A time-dependent requirement generally applies to all distributed interactive applications that aim to support real-time interaction, and is usually in terms of a few hundred milliseconds. The latency requirements are manifested in terms of event-distribution, group membership management, group dynamics, etc., far exceeding the requirements of many other applications

A network-layer proxy for bandwidth aggregation and reduction of IP packet reordering

Abstract—With today’s widespread deployment of wireless technologies, it is often the case that a single communication device can select from a variety of access networks. At the same time, there is an ongoing trend towards integration of multiple network interfaces into end-hosts, such as cell phones with HSDPA, Bluetooth and WLAN. By using multiple Internet connections concurrently, network applications can benefit from aggregated bandwidth and increased fault tolerance. However, the heterogeneity of wireless environments introduce challenges with respect to implementation, deployment, and protocol compatibility. Variable link characteristics cause reordering when sending IP packets of the same flow over multiple paths. This paper introduces a multilink proxy that is able to transparently stripe traffic destined for multihomed clients. Operating on the network layer, the proxy uses path monitoring statistics to adapt to changes in throughput and latency. Experimental results obtained from a proof-of-concept implementation verify that our approach is able to fully aggregate the throughput of heterogeneous downlink streams, even if the path characteristics change over time. In addition, our novel method of equalizing delays by buffering packets on the proxy significantly reduces IP packet reordering and the buffer requirements of clients. Index Terms—Wireless networks, heterogeneous systems, traffic analysis, network protocols, scheduling, measurements

Comorbidity and outcomes of concurrent chemo- and radiotherapy in limited disease small cell lung cancer

Background: Many patients with limited disease small cell lung cancer (LD SCLC) suffer from comorbidity. Not all patients with comorbidity are offered standard treatment, though there is little evidence for such a policy. The aim of this study was to investigate whether patients with comorbidity had inferior outcomes in a LD SCLC cohort. Material and methods: We analyzed patients from a randomized study comparing two three-week schedules of thoracic radiotherapy (TRT) plus standard chemotherapy in LD SCLC. Patients were to receive four courses of cisplatin/etoposide and TRT of 45 Gy/30 fractions (twice daily) or 42 Gy/15 fractions (once daily). Responders received prophylactic cranial irradiation (PCI). Comorbidity was assessed using the Charlson Comorbidity Index (CCI), which rates conditions with increased one-year mortality. Results: In total 157 patients were enrolled between May 2005 and January 2011. Median age was 63 years, 52% were men, 16% had performance status 2, and 72% stage III disease. Forty percent had no comorbidity; 34% had CCI-score 1; 15% CCI 2; and 11% CCI 3–5. There were no significant differences in completion rates of chemotherapy, TRT or PCI across CCI-scores; or any significant differences in the frequency of grade 3–5 toxicity (p ¼ 0.49), treatment-related deaths (p ¼ 0.36), response rates (p ¼ 0.20), progression-free survival (p ¼ 0.18) or overall survival (p ¼ 0.09) between the CCI categories. Conclusion: Patients with comorbidity completed and tolerated chemo-radiotherapy as well as other patients. There were no significant differences in response rates, progression-free survival or overall survival – suggesting that comorbidity alone is not a reason to withhold standard therapy in LD SCLC

Comorbidity and outcomes of concurrent chemo- and radiotherapy in limited disease small cell lung cancer

Background: Many patients with limited disease small cell lung cancer (LD SCLC) suffer from comorbidity. Not all patients with comorbidity are offered standard treatment, though there is little evidence for such a policy. The aim of this study was to investigate whether patients with comorbidity had inferior outcomes in a LD SCLC cohort. Material and methods: We analyzed patients from a randomized study comparing two three-week schedules of thoracic radiotherapy (TRT) plus standard chemotherapy in LD SCLC. Patients were to receive four courses of cisplatin/etoposide and TRT of 45 Gy/30 fractions (twice daily) or 42 Gy/15 fractions (once daily). Responders received prophylactic cranial irradiation (PCI). Comorbidity was assessed using the Charlson Comorbidity Index (CCI), which rates conditions with increased one-year mortality. Results: In total 157 patients were enrolled between May 2005 and January 2011. Median age was 63 years, 52% were men, 16% had performance status 2, and 72% stage III disease. Forty percent had no comorbidity; 34% had CCI-score 1; 15% CCI 2; and 11% CCI 3–5. There were no significant differences in completion rates of chemotherapy, TRT or PCI across CCI-scores; or any significant differences in the frequency of grade 3–5 toxicity (p = 0.49), treatment-related deaths (p = 0.36), response rates (p = 0.20), progression-free survival (p = 0.18) or overall survival (p = 0.09) between the CCI categories. Conclusion: Patients with comorbidity completed and tolerated chemo-radiotherapy as well as other patients. There were no significant differences in response rates, progression-free survival or overall survival – suggesting that comorbidity alone is not a reason to withhold standard therapy in LD SCLC