25 research outputs found
SchedBPF - Scheduling BPF programs
No full textThe Linux BPF framework enables the execution of verified custom bytecode in the critical path of various Linux kernel routines, allowing for efficient in-kernel extensions. The safety properties and low execution overhead of BPF programs have led to advancements in kernel extension use-cases that can be broadly categorized into tracing, custom kernel policies, and application acceleration. However, BPF is fundamentally event-driven and lacks native support for periodic or continuous tasks such as background tracing, metric aggregation, or kernel housekeeping. Existing approaches such as kernel modules with kthreads, userspace daemons, or BPF timers fail to satisfy all the essential requirements for periodic kernel extensions such as fine-grained CPU control, kernel safety, and minimal overhead.
To address this gap, we propose SchedBPF — a conceptual framework that enables periodic execution of BPF programs on kernel threads. SchedBPF program executions are sandboxed and preemptible, as governed by the existing BPF verifier and JIT engine. They also adopt time-slice semantics, cgroup-style CPU quotas, and nice-level priority control, similar to kernel threads. SchedBPF aims to enable low-overhead, periodic execution of safe BPF code with fine-grained CPU resource management.Published versio
Discovering mentorship information from author collaboration networks
No full textResearchers are assessed from a researcher-centric perspective - by quantifying a researcher's contribution to the field. Citation and publication counts are some typical examples. We propose a student-centric measure to assess researchers on their mentoring abilities. Our approach quantifies benefits bestowed by researchers upon their students by characterizing the publication dynamics of research advisor-student interactions in author collaboration networks. We show that our measures could help aspiring students identify research advisors with proven mentoring skills. Our measures also help in stratification of researchers with similar ranks based on typical indices like publication and citation counts while being independent of their direct influences
Clinical profile and outcome of H1N1 influenza in children during August 2016 to January 2017 at KIMS hospital in Bangalore, Karnataka, India
No full textBackground: Influenza virus is a common respiratory pathogen. In April 2009, a new strain of Influenza virus A H1N1 was evolved and spread in several countries around the world and caused pandemic. After that the resurgence of H1N1 epidemic occurs almost every year and it has caused significant morbidity and mortality. Author present the clinical profile of suspected cases of swine flu infection among children attending our hospital.Methods: This prospective study was conducted at KIMS hospital among 70 children aged 1month to 17 yrs admitted with pneumonia from August 2016 to January 2017 and who consented for the study were included. Institutional ethical clearance obtained. All cases were classified according to WHO ABC category and PRESS (Pediatric Respiratory Severity Score) was applied. Outcome of patients were calculated based on requirement for PICU care, ventilation and PRESS score 4-5. Suspected high risk cases, category B2, and category C cases were started on antiviral Oseltamivir and throat swabs were sent for detection of H1N1 by rRT-PCR.Results: Out of 70 pneumonia cases 44 cases improved with antibiotics and supportive therapy, 26 cases who belonged to category B2 and C and PRESS score 4-5 (severe) were screened for H1N1 influenza and 26 cases were started with empirical antiviral drug oseltamivir.10 out of 26 cases (38.4%) were positive for H1N1 influenza. In our study, fever, cough, breathlessness, and chest x-ray abnormalities were the most common clinical features in both suspected and confirmed cases of H1N1 influenza. Out of 10 cases 2 succumbed (20%). Both the cases had prolonged hospital stay.Conclusions: During monsoon, high degree of suspicion is required in patients presenting with fever, cough, cold and hurried breathing with supportive lab investigations and early administration of antiviral drug provides better outcome, reduces the length of hospital stay and mortality.</jats:p
Temporal sequencing of concepts in a function knowledge base
No full textThe author studies the involvement of time in the execution of function concepts. He proposes a directed graph model, temporal graph, to reflect the execution sequence of these concepts and shows how it can be embedded in a function knowledge base. He defines the cohesiveness coefficient of a concept on the basis of this temporal graph. Further, he states a necessary and sufficient condition for detecting simultaneous execution of concepts in a given set of objects
Graph Extraction and Demand Profiling Applications for Transportation Network Research
No full textAbstractDynamic transportation algorithms possess applications in disaster planning an emergency response. Two important prerequisites to build and test dynamic transportation network vulnerability assessment algorithms are (i) map extraction tools and (ii) an accurate network demand profile to test algorithms on these maps. This paper describes the tools built to enable dynamic transportation network vulnerability assessment algorithms, including a discussion of the architecture of the software applications developed to extract maps and collect dynamic network demand data using a smartphone app
Study of connectionless service for ATM networks and an implementation of the LAN emulation service for ATM
No full textThis project studies various approaches that provide connectionless service over Asynchronous Transfer Mode (ATM) networks that are pre-dominantly connection oriented. The two fundamentally different ways of running existing network layer protocols across an Asynchronous Transfer Mode network are examined. The "LAN Emulation" approach of emulating connectionless protocols over connection oriented ATM network is implemented in this project. The project implementation aims at seamlessly interconnecting Local Area Network (LAN) traffic over connection oriented Asynchronous Transfer Mode networks. This project details the implementation and design of the LAN Emulation protocol to emulate the characteristics of a LAN over ATM networks. This project explains the operation of the LAN Emulation protocol and also details the development and target environment in which the LAN Emulation protocol is implemented and executed. It discusses test configurations and the equipment used in performing the tests. This project provides test results and points out the limitations of the LAN Emulation protocol specification and existing implementations. Through this implementation, the author believes that although LAN Emulation protocol has its limitations, it is a very good technique to emulate LAN services over ATM networks.California State University, Northridge. Department of Computer Science.Includes bibliographical references (leaves 52-53
Video Clip Retrieval Based on LBP Variance
No full textAbstractAdvancement in technology has made the acquisition and storage of multimedia data easy and inexpensive to the end user. However for effective use of the information available in the multimedia, efficient and accurate retrieval methods are required. Multimedia based retrieval systems extensively used texture based approach to interpret and recognize a scene image. The texture of an image provides clue to the orientation, smoothness, symmetry, shape, regularity and coarness of the surface. The Local Binary Pattern Variance (LBPV) is a texture feature where variance in contrast acts as adaptive factor during computation of local binary pattern (LBP) histogram. The LBP combines both structural and statistical approaches to texture analysis. This paper proposes an LBP Variance based approach to visual content based video retrieval. The proposed approach uses query by example paradigm for retrieving similar clips from the video. Experiments conducted on TRECVID dataset shows the efficacy of proposed approach
Optimizing the Process Parameters for Electrochemical Reduction of Carbon Dioxide
No full textabstract: One the major problems of this modern industrialized world is its dependence on fossil fuels for its energy needs. Burning of fossils fuels generates green-house gases which have adverse effects on global climate contributing to global warming. According to Environmental Protection Agency (EPA), carbon dioxide makes up 80 percent of green-house gases emitted in USA. Electrochemical reduction of carbon dioxide is an approach which uses CO2 emissions to produce other useful hydrocarbons which can be used in many ways.
In this study, primary focus was on optimizing the operating conditions, determining the better catalyst material, and analyzing the reaction products for the process of electrochemical reduction of carbon dioxide (ERC). Membrane electrode assemblies (MEA’s) are developed by air bushing the metal particles with a spray gun on to Nafion-212 which is a solid polymer based electrolyte (SPE), to support the electrodes in the electrochemical reactor gas diffusion layers (GDL) are developed using porous carbon paper. Anode was always made using the same material which is platinum but cathode material was changed as it is the working electrode.
The membrane electrode assembly (MEA) is then placed into the electrochemical reactor along with gas diffusion layer (GDL) to assess the performance of the catalyst material by techniques like linear sweep voltammetry and chronoamperometry. Performance of MEA was analyzed at 4 different potentials, 2 different temperatures and for 2 different cathode catalyst materials. The reaction products of the process are analyzed using gas chromatography (GC) which has thermal conductivity detector (TCD) used for detecting hydrogen (H2), carbon monoxide (CO) and flame ionization detector (FID) used for detecting hydrocarbons. The experiments performed at 40o C gave the better results when compared with the experiments performed at ambient temperature. Also results suggested that copper oxide cathode catalyst has better durability than platinum-carbon. Maximum faradaic efficiency for methane was 5.3% it was obtained at 2.25V using copper oxide catalyst. Furthermore, experiments must be carried out to make the electrochemical reactor more robust to withstand all the operating conditions like higher potentials and to make it a solar powered reactor.Dissertation/ThesisMasters Thesis Mechanical Engineering 201
Back to the Commons: Introducing Regenerative Agricultural Networks in Northwestern Europe
No full textFor the last decades, technologies, new agricultural trade policies, environmental restrictions, high pressure through economic competition in combination with a sharp competition of land lead to the development of intensive farming. As a result, patchy landscapes have been replaced by monofunctional, homogeneous agricultural landscapes that fragment natural landscapes and take away natural and cultural diversity. The consequences of the processes of fragmentation and homogenization are both socio-economic and landscape-ecological and cause biodiversity loss and social injustice among farmers. Through changing existing paradigms about nature conservation, this project suggests an alternative approach for understanding possible interrelations between nature and agricultural practices. By reintroducing concepts about commons, a synergy can be found that compliments natural connectivity and agricultural landscapes through the establishment of a regenerative agro-ecological network that connects biotopes in a multi-functional way using current agricultural parcels and natural zones. This newly introduced Common Ground network produces a new farming method in which agricultural practice has a temporal character and is a continuous modifiable process. In this way, the vision makes use of the dual crisis as a solution rather than seeing it as the source of the problems. The Commons also resemble a new way of practising agriculture, in which land, knowledge, resources and financial risks are shared among farmers in a socially just way. In addition, these shared landscapes reflect on the social context in which farmers are considered as environmental stewards who share some of the responsibility for an ecologically balanced system.AR2U086 R&D Studio – Spatial Strategies for the Global MetropolisArchitecture, Urbanism and Building Sciences | Urbanis
