128 research outputs found

    Ind-\'etale vs Formally \'etale

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    We show that when AA is a reduced algebra over a characteristic zero field kk and the module of K\"ahler differentials ΩA/k=0\Omega_{A/k}=0, then AA is ind-\'etale, partially answering a question of Bhatt. As further applications of this result, we deduce a rigidity property of Hochschild homology and special instances of Weibel's conjecture and Vorst's conjecture without any noetherian assumptions.Comment: 13 pages. Comments welcom

    PESE: Event Structure Extraction using Pointer Network based Encoder-Decoder Architecture

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    The task of event extraction (EE) aims to find the events and event-related argument information from the text and represent them in a structured format. Most previous works try to solve the problem by separately identifying multiple substructures and aggregating them to get the complete event structure. The problem with the methods is that it fails to identify all the interdependencies among the event participants (event-triggers, arguments, and roles). In this paper, we represent each event record in a unique tuple format that contains trigger phrase, trigger type, argument phrase, and corresponding role information. Our proposed pointer network-based encoder-decoder model generates an event tuple in each time step by exploiting the interactions among event participants and presenting a truly end-to-end solution to the EE task. We evaluate our model on the ACE2005 dataset, and experimental results demonstrate the effectiveness of our model by achieving competitive performance compared to the state-of-the-art methods

    Benchmarking Hadoop performance on different distributed storage systems

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    Distributed storage systems have been in place for years, and have undergone significant changes in architecture to ensure reliable storage of data in a cost-effective manner. With the demand for data increasing, there has been a shift from disk-centric to memory-centric computing - the focus is on saving data in memory rather than on the disk. The primary motivation for this is the increased speed of data processing. This could, however, mean a change in the approach to providing the necessary fault-tolerance - instead of data replication, other techniques may be considered. One example of an in-memory distributed storage system is Tachyon. Instead of replicating data files in memory, Tachyon provides fault-tolerance by maintaining a record of the operations needed to generate the data files. These operations are replayed if the files are lost. This approach is termed lineage. Tachyon is already deployed by many well-known companies. This thesis work compares the storage performance of Tachyon with that of the on-disk storage systems HDFS and Ceph. After studying the architectures of well-known distributed storage systems, the major contribution of the work is to integrate Tachyon with Ceph as an underlayer storage system, and understand how this affects its performance, and how to tune Tachyon to extract maximum performance out of it

    Towards a General Framework for Digital Rights Management (DRM)

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    Digital rights management (DRM) can be defined as a technology that enables persistent access control. The common understanding of DRM is that of a technology that enables means to thwart piracy of digital multimedia through limiting how the media is used by the consumer. It can be observed that many of these restrictions can be applied to any type of data. Therefore, it should be possible to create a two part DRM system -- a common DRM system that enforces the basic access controls (such as read, write and execute) and an application specific DRM system that enforces the application specific access controls (such as print and play). The aim of this dissertation is to create such a framework for distribution independent DRM systems. Most vendors promote DRM as a copyright protection mechanism, and thus consumers expect a number of rights that are allowed by copyright legislation, but which are not available for the DRM protected media. However, DRM is not an enforcement of copyright law, but rather an enforcement of a licensing regime. Thus, there is incorrect (and possibly false) marketing of DRM enabled media from the vendors of DRM enabled media, leading to dissatisfied consumers. We think that one of the main reasons for the current situation, is that there is no defined legal framework governing the operation of DRM systems. In this dissertation, we address this gap, by developing a legal framework for DRM systems as one of the components of our DRM framework. Negotiation can be defined as the process which leads to the conclusion of a contract. Since DRM is the enforcement of licensing agreements, there is a need to cater for negotiation protocols in DRM systems. Negotiations provide the consumer with the power to request different rights packages, especially when consumers have a legitimate need for rights not granted normally to other consumers (for example, disabled consumers have needs that may not be met with standard rights set). Negotiations also allow the possibility for the licensors to extract the maximum value from the consumers. For this reason, the inclusion of negotiation protocols in DRM systems can become a powerful tool, and in this dissertation we present the first negotiation protocols for DRM systems. Even though the definition of DRM as an access control model has existed since at least 2002, there has been no formal description of DRM as an access control model. Thus, there are no formal models for any of the rights expression languages which express DRM access control policies, and various authors have commented on ambiguities present in interpretation and enforcement of licenses expressed in these languages -- a result of a lack of formal definition of these languages. In this dissertation, we develop a formal model for a Licensing Rights Expression Language (LiREL), which is designed to provide a mechanism to express access control policies which are also sound legal license documents. Our formal model also discusses the enforcement of the access control policies, and is thus the first formal model for DRM as a mechanism for access control. Access control is a two part process: authentication of the parties involved and authorisation of the parties to access the resources. Authorisation in DRM provides some unique challenges: there is a need to support multiple platforms, without guaranteed network connectivity and minimal trust between the parties involved. For this reason, the associated authentication framework becomes more complex. While many access control models define user management as part of their model, we have taken a different approach, and removed user management from the core DRM system. Instead, our authorisation process requires a trusted verification of the user's credentials and then decides on the access control request. For this reason, our user authentication framework is ticket based, and shares similarities to Kerberos tickets. DRM also requires a strong data identity management. However, all the current identity systems for data do not provide verification service for data identity. For this reason, we developed Verifiable Digital Object Identity (VDOI) System, to address this gap. These components are combined towards a general framework for digital rights management that advances the understanding, organisation and implementation of DRM compared to approaches or solutions which are currently available

    Practices regarding prescription and dispensing of drugs in a tertiary care hospital in rural West Bengal, India

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    Background: Irrational prescription practices are a distressing global problem, especially in the developing countries. A study was conducted to assess the patterns of prescribing and dispensing drugs in a tertiary healthcare centre serving a large rural population in the eastern India.Methods: A cross-sectional observational study was conducted from July-September 2016 in the general out-patient department and the institution pharmacy of a tertiary care hospital of West Bengal, India. Data were congregated by collection and review of individual prescriptions, measuring the time of interaction between patients and prescribers/dispensers, and conducting patient interviews at exit.Results: Analysis of the collected and tabulated data revealed that after average, 2.5 medicines were prescribed per prescription, with 95.26% being under their generic name. Of the drugs prescribed, 95.79% were from the essential drug list. The average consultation time was 150.0s (SD 62.3s) and average dispensing time was 81.5s (SD 51.2s). Of the drugs prescribed, 86.12% of drugs were actually dispensed from the institution pharmacy but none of the drugs were labeled. The percentage of prescriptions with an antibiotic was 47.83%, while injections were recorded on in 2.83% of the prescriptions. Percentage of patients who had knowledge of the dosage of the drugs prescribed to them was 91.67%.Conclusions: While the study found high percentages of drugs prescribed under generic names high percentage of drugs actually prescribed from the Institution Pharmacy, prescription of drugs from the Essential Drugs List, and a low number of injections per prescription conforming to WHO set standards, it also found a lack of drug labelling, high percentage of prescription of antibiotics to be indicators that do not conform with the WHO set international standards

    High Frobenius pushforwards generate the bounded derived category

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    This work concerns generators for the bounded derived category of coherent sheaves over a noetherian scheme XX of prime characteristic. The main result is that when the Frobenius map on XX is finite, for any compact generator GG of D(X)\mathsf{D}(X) the Frobenius pushforward F∗eGF ^e_*G generates the bounded derived category for whenever pep^e is larger than the codepth of XX, an invariant that is a measure of the singularity of XX. The conclusion holds for all positive integers ee when XX is locally complete intersection. The question of when one can take G=OXG=\mathcal{O}_X is also investigated. For smooth projective complete intersections reduces to a question of generation of the Kuznetsov component.Comment: 31 page

    Nostradamus: Weathering Worth

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    Nostradamus, inspired by the French astrologer and reputed seer, is a detailed study exploring relations between environmental factors and changes in the stock market. In this paper, we analyze associative correlation and causation between environmental elements and stock prices based on the US financial market, global climate trends, and daily weather records to demonstrate significant relationships between climate and stock price fluctuation. Our analysis covers short and long-term rises and dips in company stock performances. Lastly, we take four natural disasters as a case study to observe their effect on the emotional state of people and their influence on the stock market.Comment: 12 pages, 13 figure
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