Cost-Efficient Storage for On-Demand Video Streaming on Cloud

Video stream is converted to several formats to support the user's device, this conversion process is called video transcoding, which imposes high storage and powerful resources. With emerging of cloud technology, video stream companies adopted to process video on the cloud. Generally, many formats of the same video are made (pre-transcoded) and streamed to the adequate user's device. However, pre-transcoding demands huge storage space and incurs a high-cost to the video stream companies. More importantly, the pre-transcoding of video streams could be hierarchy carried out through different storage types in the cloud. To minimize the storage cost, in this paper, we propose a method to store video streams in the hierarchical storage of the cloud. Particularly, we develop a method to decide which video stream should be pre-transcoded in its suitable cloud storage to minimize the overall cost. Experimental simulation and results show the effectiveness of our approach, specifically, when the percentage of frequently accessed videos is high in repositories, the proposed approach minimizes the overall cost by up to 40 percent.Comment: International IEEE World Forum for Internet of Thing

Je ne serai libre que le jour où ma patrie sera libre !

Poète avant tout, Mahmoud Darwich se veut chantre de l’espoir tout en étant conscient que la chanson ne guérit pas la blessure. Poète sous pression, ses solutions ne peuvent être que métaphoriques. Nourri de poésie antéislamique dont il s’interroge sur la perfection, M. D. n’écrit pas pour autant de poésie classique. Quant à sa relation avec les textes sacrés, elle est avant tout une relation littéraire et il ne puise que dans les mythes de l’ancien et du nouveau testament. Plutôt qu’un État palestinien souverain, M. D. croit davantage en un État binational. Et pour ce qui est du rôle de «l’intellectuel arabe», il conseille tout simplement d’abandonner ce concept. Mahmoud Darwish a publié plus de 30 recueils de poèmes et de textes en prose, et son oeuvre a été traduite en 35 langues. Il est le fondateur et rédacteur de la revue littéraire fort estimée Al Karmel, qui encourage le débat interculturel sur les questions intellectuelles et crée le lien entre les écrivains arabes et la communauté littéraire internationale». (NdR)Darwich Mahmoud. Je ne serai libre que le jour où ma patrie sera libre !. In: Horizons Maghrébins - Le droit à la mémoire, N°57, 2007. Créations palestiniennes. pp. 12-18

Cost-Efficient Video On Demand (VOD) Streaming Using Cloud Services

Video streaming has become ubiquitous and pervasive in usage of the electronic displaying devices. Streaming becomes more challenging when dealing with an enormous number of video streams. Particularly, the challenges lie in streaming types, video transcoding, video storing, and video delivering to users with high satisfaction and low cost for video streaming providers. In this dissertation, we address the challenges and issues encountered in video streaming and cloud-based video streaming. Specically, we study the impact factors on video transcoding in the cloud, and then we develop a model to trade-o between performance and cost of cloud. On the other hand, video streaming providers generally have to store several formats of the same video and stream the appropriate format based on the characteristics of the viewer's device. This approach, called pre-transcoding, incurs a signicant cost to the stream providers that rely on cloud services. Furthermore, pre-transcoding is proven to be inecient due to the long-tail access pattern to video streams. To reduce the incurred cost, we propose to pre-transcode only frequently-accessed videos (called hot videos) and partially pre-transcode others, depending on their hotness degree. Therefore, we need to measure video stream hotness. Accordingly, we first, provide a model to measure the hotness of video streams. Then, we develop methods that operate based on the hotness measure and determine how to pre-transcode videos to minimize the cost of stream providers. The partial pre-transcoding methods operate at dierent granularity levels to capture dierent patterns in accessing videos. Particularly, one of the methods operates faster but cannot partially pre-transcode videos with the non-long-tail access pattern. Experimental results show the ecacy of our proposed methods, specically, when a video stream repository includes a high percentage of Frequently Accessed Video Streams and a high percentage of videos with the non-long-tail accesses pattern

Naji, notre pain quotidien (traduit par A. O. Alami)

Darwich Mahmoud, Ouali Alami Abdallah. Naji, notre pain quotidien (traduit par A. O. Alami). In: Horizons Maghrébins - Le droit à la mémoire, N°57, 2007. Créations palestiniennes. pp. 159-160

Stoma-free survival after anastomotic leak following rectal cancer resection: worldwide cohort of 2470 patients

Background: The optimal treatment of anastomotic leak after rectal cancer resection is unclear. This worldwide cohort study aimed to provide an overview of four treatment strategies applied. Methods: Patients from 216 centres and 45 countries with anastomotic leak after rectal cancer resection between 2014 and 2018 were included. Treatment was categorized as salvage surgery, faecal diversion with passive or active (vacuum) drainage, and no primary/secondary faecal diversion. The primary outcome was 1-year stoma-free survival. In addition, passive and active drainage were compared using propensity score matching (2: 1). Results: Of 2470 evaluable patients, 388 (16.0 per cent) underwent salvage surgery, 1524 (62.0 per cent) passive drainage, 278 (11.0 per cent) active drainage, and 280 (11.0 per cent) had no faecal diversion. One-year stoma-free survival rates were 13.7, 48.3, 48.2, and 65.4 per cent respectively. Propensity score matching resulted in 556 patients with passive and 278 with active drainage. There was no statistically significant difference between these groups in 1-year stoma-free survival (OR 0.95, 95 per cent c.i. 0.66 to 1.33), with a risk difference of -1.1 (95 per cent c.i. -9.0 to 7.0) per cent. After active drainage, more patients required secondary salvage surgery (OR 2.32, 1.49 to 3.59), prolonged hospital admission (an additional 6 (95 per cent c.i. 2 to 10) days), and ICU admission (OR 1.41, 1.02 to 1.94). Mean duration of leak healing did not differ significantly (an additional 12 (-28 to 52) days). Conclusion: Primary salvage surgery or omission of faecal diversion likely correspond to the most severe and least severe leaks respectively. In patients with diverted leaks, stoma-free survival did not differ statistically between passive and active drainage, although the increased risk of secondary salvage surgery and ICU admission suggests residual confounding

Stoma-free Survival After Rectal Cancer Resection With Anastomotic Leakage: Development and Validation of a Prediction Model in a Large International Cohort.

Objective:To develop and validate a prediction model (STOMA score) for 1-year stoma-free survival in patients with rectal cancer (RC) with anastomotic leakage (AL).Background:AL after RC resection often results in a permanent stoma.Methods:This international retrospective cohort study (TENTACLE-Rectum) encompassed 216 participating centres and included patients who developed AL after RC surgery between 2014 and 2018. Clinically relevant predictors for 1-year stoma-free survival were included in uni and multivariable logistic regression models. The STOMA score was developed and internally validated in a cohort of patients operated between 2014 and 2017, with subsequent temporal validation in a 2018 cohort. The discriminative power and calibration of the models' performance were evaluated.Results:This study included 2499 patients with AL, 1954 in the development cohort and 545 in the validation cohort. Baseline characteristics were comparable. One-year stoma-free survival was 45.0% in the development cohort and 43.7% in the validation cohort. The following predictors were included in the STOMA score: sex, age, American Society of Anestesiologist classification, body mass index, clinical M-disease, neoadjuvant therapy, abdominal and transanal approach, primary defunctioning stoma, multivisceral resection, clinical setting in which AL was diagnosed, postoperative day of AL diagnosis, abdominal contamination, anastomotic defect circumference, bowel wall ischemia, anastomotic fistula, retraction, and reactivation leakage. The STOMA score showed good discrimination and calibration (c-index: 0.71, 95% CI: 0.66-0.76).Conclusions:The STOMA score consists of 18 clinically relevant factors and estimates the individual risk for 1-year stoma-free survival in patients with AL after RC surgery, which may improve patient counseling and give guidance when analyzing the efficacy of different treatment strategies in future studies