571 research outputs found

    On the Complexity of Temporal-Logic Path Checking

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    Given a formula in a temporal logic such as LTL or MTL, a fundamental problem is the complexity of evaluating the formula on a given finite word. For LTL, the complexity of this task was recently shown to be in NC. In this paper, we present an NC algorithm for MTL, a quantitative (or metric) extension of LTL, and give an NCC algorithm for UTL, the unary fragment of LTL. At the time of writing, MTL is the most expressive logic with an NC path-checking algorithm, and UTL is the most expressive fragment of LTL with a more efficient path-checking algorithm than for full LTL (subject to standard complexity-theoretic assumptions). We then establish a connection between LTL path checking and planar circuits, which we exploit to show that any further progress in determining the precise complexity of LTL path checking would immediately entail more efficient evaluation algorithms than are known for a certain class of planar circuits. The connection further implies that the complexity of LTL path checking depends on the Boolean connectives allowed: adding Boolean exclusive or yields a temporal logic with P-complete path-checking problem

    Cost-effectiveness Study of Antihypertensive Drugs in Mumbai, India

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    Hypertension is a serious global public health problem. It accounts for 10% of all deaths in India and is the leading noncommunicable disease.1 Recent studies have shown that the prevalence of hypertension is 25% in urban and 10% in rural people in India.2 It exerts a substantial public health burden on cardiovascular health status and health care systems in India.3 Antihypertensive treatment effectively reduces hypertension-related morbidity and mortality.1 The cost of medications has always been a barrier to effective treatment

    Balancing Bounded Treewidth Circuits

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    Algorithmic tools for graphs of small treewidth are used to address questions in complexity theory. For both arithmetic and Boolean circuits, it is shown that any circuit of size nO(1)n^{O(1)} and treewidth O(login)O(\log^i n) can be simulated by a circuit of width O(logi+1n)O(\log^{i+1} n) and size ncn^c, where c=O(1)c = O(1), if i=0i=0, and c=O(loglogn)c=O(\log \log n) otherwise. For our main construction, we prove that multiplicatively disjoint arithmetic circuits of size nO(1)n^{O(1)} and treewidth kk can be simulated by bounded fan-in arithmetic formulas of depth O(k2logn)O(k^2\log n). From this we derive the analogous statement for syntactically multilinear arithmetic circuits, which strengthens a theorem of Mahajan and Rao. As another application, we derive that constant width arithmetic circuits of size nO(1)n^{O(1)} can be balanced to depth O(logn)O(\log n), provided certain restrictions are made on the use of iterated multiplication. Also from our main construction, we derive that Boolean bounded fan-in circuits of size nO(1)n^{O(1)} and treewidth kk can be simulated by bounded fan-in formulas of depth O(k2logn)O(k^2\log n). This strengthens in the non-uniform setting the known inclusion that SC0NC1SC^0 \subseteq NC^1. Finally, we apply our construction to show that {\sc reachability} for directed graphs of bounded treewidth is in LogDCFLLogDCFL

    A study of assessment of knowledge, attitude and practice of antibiotic stewardship among healthcare providers in a tertiary care hospital of Sangli

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    Background: Antimicrobials are routinely used for variety of clinical conditions but are also misused leading to drug resistance bacteria in clinical practice. Consultants can gain the knowledge about it and can also have the depth of problem faced, their prescribing behavior mainly depends on their attitude and understanding of condition. Our aim of this study is to evaluate the knowledge and beliefs about antibiotics prescribing among health care workers in a tertiary care hospital of Sangli. Methods: Our present study was conducted in the Bharati hospital, BV (DU) medical college and hospital, Sangli. Ethical clearance from the institutional ethics committee was obtained and it was, cross-sectional questionnaire-based study carried out in the form of a survey in which a pretested, semi-structured, validated questionnaire was provided to junior residents, senior residents and faculty of different specialties and responses were recorded. Questionnaire comprises of 9 in knowledge, 10 in attitude and 10 in practice section. Results: Out of all participants 84.5% believed that no need of antibiotics for running and blocked nose. Majority 89.6% were expressed that sample culture should be sent before starting antibiotics. 90.4% participants believed that education of patients will help. Only 76.8% strictly adhere to the antibiotic policy of our hospital. Conclusions: The present study on antibiotic usage gives useful information about the knowledge, attitudes and practices of prescribers and help plan suitable educational modifications that aim at improving the antimicrobial prescribing and minimizing the development of drug resistance in our developing country

    Venus Express radio occultation observed by PRIDE

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    Context. Radio occultation is a technique used to study planetary atmospheres by means of the refraction and absorption of a spacecraft carrier signal through the atmosphere of the celestial body of interest, as detected from a ground station on Earth. This technique is usually employed by the deep space tracking and communication facilities (e.g., NASA's Deep Space Network (DSN), ESA's Estrack). Aims. We want to characterize the capabilities of the Planetary Radio Interferometry and Doppler Experiment (PRIDE) technique for radio occultation experiments, using radio telescopes equipped with Very Long Baseline Interferometry (VLBI) instrumentation. Methods. We conducted a test with ESA's Venus Express (VEX), to evaluate the performance of the PRIDE technique for this particular application. We explain in detail the data processing pipeline of radio occultation experiments with PRIDE, based on the collection of so-called open-loop Doppler data with VLBI stations, and perform an error propagation analysis of the technique. Results. With the VEX test case and the corresponding error analysis, we have demonstrated that the PRIDE setup and processing pipeline is suited for radio occultation experiments of planetary bodies. The noise budget of the open-loop Doppler data collected with PRIDE indicated that the uncertainties in the derived density and temperature profiles remain within the range of uncertainties reported in previous Venus' studies. Open-loop Doppler data can probe deeper layers of thick atmospheres, such as that of Venus, when compared to closed-loop Doppler data. Furthermore, PRIDE through the VLBI networks around the world, provides a wide coverage and range of large antenna dishes, that can be used for this type of experiments

    Bridging Python to Silicon: The SODA Toolchain

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    Systems performing scientific computing, data analysis, and machine learning tasks have a growing demand for application-specific accelerators that can provide high computational performance while meeting strict size and power requirements. However, the algorithms and applications that need to be accelerated are evolving at a rate that is incompatible with manual design processes based on hardware description languages. Agile hardware design tools based on compiler techniques can help by quickly producing an application specific integrated circuit (ASIC) accelerator starting from a high-level algorithmic description. We present the SODA Synthesizer, a modular and open-source hardware compiler that provides automated end-to-end synthesis from high-level software frameworks to ASIC implementation, relying on multi-level representations to progressively lower and optimize the input code. Our approach does not require the application developer to write register-transfer level code, and it is able to reach up to 364 GFLOPS/W efficiency (32-bit precision) on typical convolutional neural network operators
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