System Support for Bandwidth Management and Content Adaptation in Internet Applications

This paper describes the implementation and evaluation of an operating system module, the Congestion Manager (CM), which provides integrated network flow management and exports a convenient programming interface that allows applications to be notified of, and adapt to, changing network conditions. We describe the API by which applications interface with the CM, and the architectural considerations that factored into the design. To evaluate the architecture and API, we describe our implementations of TCP; a streaming layered audio/video application; and an interactive audio application using the CM, and show that they achieve adaptive behavior without incurring much end-system overhead. All flows including TCP benefit from the sharing of congestion information, and applications are able to incorporate new functionality such as congestion control and adaptive behavior.Comment: 14 pages, appeared in OSDI 200

Natural Gas as Feedstock for Fertilizer

Separation of the hydrogen needed for the ammonia synthesis reaction, from its source is difficult. Hydrogen production method is the main source of distinction between the various ammonia production routes. Most of the improvements in the technology regarding the ammonia synthesis were concerned with the hydrogen production step. Hydrogen can be produced by steam reforming, partial oxidation and water electrolysis. The bulk of the world ammonia production is based on steam reforming. The major hydrogen sources are natural gas, naphtha and coal. In this project different methods available for hydrogen separation from its source are analyzed and the best possible way to produce synthesis gas (which will form ammonia) from natural gas is found out. The number of reforming stages required for a plant capacity of 1500 tons per day of ammonia production is found out. The mass balance and energy balance calculations for the above said plant capacity is presented in this work. Then the conventional carbon dioxide removal process and methanation process are replaced by the advanced, economical pressure swing adsorption process. It was also found that two stages of shift converters required for this plant capacity. The number of reforming stages required is only one and nitrogen is obtained from oxygen pressure swing absorption units. The oxygen separated is also used as a fuel with natural gas for reforming. The carbon dioxide is separated in another PSA which can be used for the production of urea

Ensuring data plane consistency in SDN-based publish/subscribe systems

Content-Based publish/subscribe paradigm is a widely used paradigm which enables applications to share events, and allow the integrated applications to remain loosely coupled. The importance of the paradigm increases further with the emergence of IoT applications, a micro service approach to application development, etc. With the rise in the amount of data being shared between applications, there is a need to provide high data rate and bandwidth efficiency, and the introduction of Software Defined Networking(SDN)-based pub/sub, it becomes possible to achieve both. Content-based pub/sub built on SDN uses the IP address match fields of the flows in Ternary Content-Addressable Memory(TCAM) as content filters. While such an in-network filtering offers high data rate, it also involves frequent updates in the data-plane to keep the system running optimally. Although pub/sub using SDN is efficient, to use it in real-time, it needs to ensure some level of consistency when updating content-filters in the data plane so that events are not subjected to black holes, duplicates, loops, etc. Keeping the requirement of ensuring consistency in mind, the goals of this thesis include an analysis of the data plane consistency issues related to SDN-based pub/sub, to apply existing algorithms or implement new algorithms to preserve consistency of the data plane, and to provide an evaluation comparing all the implemented solutions

CYTOMORPHOMETRIC ANALYSIS OF BUCCAL CELLS IN BUILDING WORKERS EXPOSED TO POLYCYCLIC AROMATIC HYDROCARBON IN AND AROUND COIMBATORE DISTRICT

Objective: Building workers are exposed to a mixture of chemicals and polycyclic aromatic hydrocarbons at the time exposure by inhalation which is suspected to cause genetic damage. The aim of the study was to assess the level of genetic damage in south Indian building workers are exposed to PAHs.Methods: 30 Building workers and standardized control groups are examined for frequencies of micronuclei in buccal epithelial cells.Results: The genetic damage observed in the buccal cells of building workers was significantly higher than in controls. Chewing also related to genetic damage since the observed in PAHs exposed groups with chewers was significantly higher than non-chewing workers.Conclusion: Occupational exposure of PAHs from building workplaces has been associated with increased genetic damage and chewers represent an additional risk factor. Exposure to PAHs may be related to increased risk of cancer in building workers

Towards Quantifying the Distance between Opinions

Increasingly, critical decisions in public policy, governance, and business strategy rely on a deeper understanding of the needs and opinions of constituent members (e.g. citizens, shareholders). While it has become easier to collect a large number of opinions on a topic, there is a necessity for automated tools to help navigate the space of opinions. In such contexts understanding and quantifying the similarity between opinions is key. We find that measures based solely on text similarity or on overall sentiment often fail to effectively capture the distance between opinions. Thus, we propose a new distance measure for capturing the similarity between opinions that leverages the nuanced observation -- similar opinions express similar sentiment polarity on specific relevant entities-of-interest. Specifically, in an unsupervised setting, our distance measure achieves significantly better Adjusted Rand Index scores (up to 56x) and Silhouette coefficients (up to 21x) compared to existing approaches. Similarly, in a supervised setting, our opinion distance measure achieves considerably better accuracy (up to 20% increase) compared to extant approaches that rely on text similarity, stance similarity, and sentiment similarityComment: Accepted in ICWSM '2

Studies on green house gas emissions from rice field in Rwanda

The overall objective of this research is to estimate the Green House Gases (GHGs) emissions in different time of the day and to bring out the time of maximum and minimum GHGs emissions from the rice field. An experiment was conducted to estimate the GHGs emission from the rice fields of Muvumba P-8. Gas collection chambers were installed in 9 plots to collect the greenhouse gases. The gas samples were analyzed in Gas Chromatography and converted its results in to usable form. There was marked difference in the mean CO2 gas emission among the plots. The overall mean of CO2 gas emission among the experimental plots was 1950521 μg m-2 h-1. CH4 gas emission was high at 9 am and the minimum is at 3 pm among the mean gas production. Maximum CH4 gas emission at 9 am is due to the fact that during night time rice plant takes more CH4 and release the same due to ambient temperature rise at 9 am. The minimum CH4 gas emission at 3 pm is due to the fact that rice plant released all its CH4 during day time around 9 am to 3 pm and there was less CH4 in the rice plant to release at 3 pm. The mean of N2O gas emission at 6 am, 9 am, 12 noon and 3 pm of all the experimental plots was found to be 960.86 μg m-2 h-1. The mean N2O gas emission at 9am was found to be 995.82μg m-2 h-1. The important conclusion from the study is that N2O gas emission at 6 am and 12 noon are behaving similarly with decreasing trend. It was also found that N2O gas emission at 9 am and 3 pm are behaving similarly with decreasing trend.Keywords: Rice field, Green House Gases, emission, marshlan

Double Trouble – Synchronous Primary Malignant Neoplasms: A Case Report

Synchronous primary malignancy (SPM) is rare. We herein present a case of gastric carcinoma (GC) and renal cell carcinoma (RCC) to highlight the fact that the occurrence of RCC as a synchronous tumor along with GC is rare and that a high index of suspicion of SPM should be considered before declaring it as a metastasis. A 60-year-old male presented with abdominal pain and vomiting for 4 months, and a mass was incidentally found in the lumbar region. The patient was diagnosed with SPM of the GC and RCC. Chemotherapy was given, followed by total gastrectomy; radical nephrectomy was performed. The patient is currently on follow-up. Complete history taking and thorough physical examination of patients with malignancy is instrumental in ruling out metastasis and other synchronous lesions, especially in GC. Synchronous malignancies should be treated with the multidisciplinary team, as there is no consensus in the treatment protoco