10 research outputs found

    Deployment and Debugging of Real-Time Applications on Multicore Architectures

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    It is essential to enable information extraction from software. Program tracing techniques are an example of information extraction. Program tracing extracts information from the program during execution. Tracing helps with the testing and validation of software to ensure that the software under test is correct. Information extraction is done by instrumenting the program. Logged information can be stored in dedicated logging memories or can be buffered and streamed off-chip to an external monitor. The designer inspects the trace after execution to identify potentially erroneous state information. In addition, the trace can provide the state information that serves as input to generate the erroneous output for reproducibility. Information extraction can be difficult and expensive due to the increase in size and complexity of modern software systems. For the sub-class of software systems known as real-time systems, these issues are further aggravated. This is because real-time systems demand timing guarantees in addition to functional correctness. Consequently, any instrumentation to the original program code for the purpose of information extraction may affect the temporal behaviors of the program. This perturbation of temporal behaviors can lead to the violation of timing constraints, which may bias the program execution and/or cause the program to miss its deadline. As a result, there is considerable interest in devising techniques to allow for information extraction without missing a program’s deadline that is known as time-aware instrumentation. This thesis investigates time-aware instrumentation mechanisms to instrument programs while respecting their timing constraints and functional behavior. Knowledge of the underlying hardware on which the software runs, enables the extraction of more information via the instrumentation process. Chip-multiprocessors offer a solution to the performance bottleneck on uni-processors. Providing timing guarantees for hard real-time systems, however, on chip-multiprocessors is difficult. This is because conventional communication interconnects are designed to optimize the average-case performance. Therefore, researchers propose interconnects such as the priority-aware networks to satisfy the requirements of hard real-time systems. The priority-aware interconnects, however, lack the proper analysis techniques to facilitate the deployment of real-time systems. This thesis also investigates latency and buffer space analysis techniques for pipelined communication resource models, as well as algorithms for the proper deployment of real-time applications to these platforms. The analysis techniques proposed in this thesis provide guarantees on the schedulability of real-time systems on chip-multiprocessors. These guarantees are based on reducing contention in the interconnect while simultaneously accurately computing the worst-case communication latencies. While these worst-case latencies provide bounds for computing the overall worst-case execution time of applications on chip-multiprocessors, they also provide means to assigning instrumentation budgets required by time-aware instrumentation. Leveraging these platform-specific analysis techniques for the assignment of instrumentation budgets, allows for extracting more information from the instrumentation process

    Experimentally Comparative Study on Different Strengthening Methods of Reinforced Concrete Deep Beams

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    The aim of this study is to investigate the effect of strengthening reinforced concrete deep beams. An experimental study was done using six reinforced concrete deep beams have the same dimensions of 1150×800×150 mm, and subjected to mid-span concentrated load up to failure. Beams were different in the type, Location of strengthening and the ratio of reinforcement. Beams were divided into three groups. The first group included beams strengthened internally by single strut and either vertical or horizontal additional reinforcement. The second group included beams strengthened using double embedded strut or using CFRP as external strengthening. The third group included one beam strengthened using inclined stirrups. One of the specimens was tested without any strengthening and one specimen was strengthened by external CFRP sheets for comparison purposes the results of the experimental study shown remarkable improvement for using each type of strengthening. Results shown that using the mechanism of increasing stirrups by double rate and using single strut reinforcing is the optimum choice. This is due to the fact that this type of strengthening provides significant increase in the beam capacity in additional to the enhanced behavior of the beam. By this study comparison between each type of strengthening was done and the optimum type to be used in accordance with parameters of gained load capacity of tested deep beams

    Static Slack-Based Instrumentation of Programs

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    Abstract-Real-time embedded programs are time sensitive and, to trace such programs, the instrumentation mechanism must honor the programs' timing constraints. We present a time-aware instrumentation technique that injects program code with slack-based conditional instrumentation. The central idea is to execute instrumentation code only when its execution does not increase the worst-case execution time beyond a program's deadline. This occurs at run-time. Unlike previous efforts, this work allows instrumenting on the path that results in the worstcase execution time of the program. We propose a software, and a hardware method of allowing for slack-based conditional instrumentation. We evaluate and compare these two alternatives using a common benchmark suite for real-time systems. Our results show that, on average, the two proposed methods achieve 57% and 80% instrumentation coverage, respectively, compared to only a 3% coverage by previous work

    Finite element modeling of RC shear walls strengthened with CFRP subjected to cyclic loading

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    This paper presents a numerical modeling of RC shear walls using ANSYS finite element program. The objective of this research is to study the effect of using FRP sheets to enhance the seismic behavior of RC shear wall buildings designed according to old code provisions. These structures exhibit a number of structural problems such as insufficient shear reinforcement and poor concrete confinement at the boundaries. The walls were subjected to monotonic and reversed cyclic loading up to failure.In this research, response of FRP-retrofitted RC shear walls subjected to lateral loads is studied using the general-purpose finite element code ANSYS. The numerical modeling is first validated against available experimental results from the literature. A total of seven wall specimens from two experimental programs were modeled and analyzed under monotonic and reversed cyclic loading. The FRP sheets are used in both the vertical and horizontal directions of the walls to enhance stiffness, flexural strength, shear capacity, ductility and concrete confinement of the walls. The analytical results show that FRP material is effective in eliminating the brittle shear failure mode in walls with insufficient shear reinforcement. The numerical outputs in terms of load–displacements are in good agreement with the experimental results. Keywords: RC shear walls, Seismic behavior, Monotonic loading, Cyclic loading, CFRP sheet

    Predicting Compressive Strength of Blast Furnace Slag and Fly Ash Based Sustainable Concrete Using Machine Learning Techniques: An Application of Advanced Decision-Making Approaches

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    The utilization of waste industrial materials such as Blast Furnace Slag (BFS) and Fly Ash (F. Ash) will provide an effective alternative strategy for producing eco-friendly and sustainable concrete production. However, testing is a time-consuming process, and the use of soft machine learning (ML) techniques to predict concrete strength can help speed up the procedure. In this study, artificial neural networks (ANNs) and decision trees (DTs) were used for predicting the compressive strength of the concrete. A total of 1030 datasets with eight factors (OPC, F. Ash, BFS, water, days, SP, FA, and CA) were used as input variables for the prediction of concrete compressive strength (response) with the help of training and testing individual models. The reliability and accuracy of the developed models are evaluated in terms of statistical analysis such as R2, RMSE, MAD and SSE. Both models showed a strong correlation and high accuracy between predicted and actual Compressive Strength (CS) along with the eight factors. The DT model gave a significant relation to the CS with R2 values of 0.943 and 0.836, respectively. Hence, the ANNs and DT models can be utilized to predict and train the compressive strength of high-performance concrete and to achieve long-term sustainability. This study will help in the development of prediction models for composite materials for buildings

    Low-dose recombinant properdin provides substantial protection against Streptococcus pneumoniae and Neisseria meningitidis infection

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    Modern medicine has established three central antimicrobial therapeutic concepts: vaccination, antibiotics, and, recently, the use of active immunotherapy to enhance the immune response toward specific pathogens. The efficacy of vaccination and antibiotics is limited by the emergence of new pathogen strains and the increased incidence of antibiotic resistance. To date, immunotherapy development has focused mainly on cytokines. Here we report the successful therapeutic application of a complement component, a recombinant form of properdin (P[subscript: n]), with significantly higher activity than native properdin, which promotes complement activation via the alternative pathway, affording protection against N. menigitidis and S. pneumoniae. In a mouse model of infection, we challenged C57BL/6 WT mice with N. menigitidis B-MC58 6 h after i.p. administration of P[subscript: n] (100 µg/mouse) or buffer alone. Twelve hours later, all control mice showed clear symptoms of infectious disease while the P[subscript: n] treated group looked healthy. After 16 hours, all control mice developed sepsis and had to be culled, while only 10% of P[subscript: n] treated mice presented with sepsis and recoverable levels of live Meningococci. In a parallel experiment, mice were challenged intranasally with a lethal dose of S. pneumoniae D39. Mice that received a single i.p. dose of P[subscript: n] at the time of infection showed no signs of bacteremia at 12 h postinfection and had prolonged survival times compared with the saline-treated control group (P < 0.0001). Our findings show a significant therapeutic benefit of P[subscript: n] administration and suggest that its antimicrobial activity could open new avenues for fighting infections caused by multidrug-resistant neisserial or streptococcal strains

    Outcomes in Newly Diagnosed Atrial Fibrillation and History of Acute Coronary Syndromes: Insights from GARFIELD-AF

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    BACKGROUND: Many patients with atrial fibrillation have concomitant coronary artery disease with or without acute coronary syndromes and are in need of additional antithrombotic therapy. There are few data on the long-term clinical outcome of atrial fibrillation patients with a history of acute coronary syndrome. This is a 2-year study of atrial fibrillation patients with or without a history of acute coronary syndromes

    Analysis of Outcomes in Ischemic vs Nonischemic Cardiomyopathy in Patients With Atrial Fibrillation A Report From the GARFIELD-AF Registry

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    IMPORTANCE Congestive heart failure (CHF) is commonly associated with nonvalvular atrial fibrillation (AF), and their combination may affect treatment strategies and outcomes
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