Unifying Synchronization and Events in a Multicore Operating System

We address the problem of specifying concurrent processes that can make local nondeterministic decisions without affecting global system behavior—the sequence of events communicated along each inter-process communication channel. Such nondeterminism can be used to cope with unpredictable execution rates and communication delays. Our model resembles Kahn’s, but does not include unbounded buffered communication, so it is much simpler to reason about and implement. After formally characterizing these so-called confluent processes, we propose a collection of operators, including sequencing, parallel, and our own creation, confluent choice, that guarantee confluence by construction. The result is a set of primitive constructs that form the formal basis of a concurrent programming language for both hardware and software systems that gives deterministic behavior regardless of the relative execution rates of the processes. Such a language greatly simplifies the verification task because any correct implementation of such a system is guaranteed to have the same behavior, a property rarely found in concurrent programming environments.

Millions of users share their experiences, thoughts, and interests online, through social media sites (e.g., Twitter, Flickr, YouTube). As a result, these sites host a substantial number of user-contributed documents (e.g., textual messages, photographs, videos) for a wide variety of events (e.g., concerts, political demonstrations, earthquakes). In this dissertation, we present techniques for leveraging the wealth of available social media documents to identify and characterize events of different types and scale. By automatically identifying and characterizing events and their associated user-contributed social media documents, we can ultimately offer substantial improvements in browsing and search quality for event content. To understand the types of events that exist in social media, we first characterize a large set of events using their associated social media documents. Specifically, we develop a taxonomy of events in social media, identify important dimensions along which they can be categorized, and determine the key distinguishing features that can be derived from their associated documents. We quantitatively examine the computed features for different categories of events, and establish that significant differences can be detected across categories. Importantly, we observe differences between events and other non-event content that exists in social media. We use these observations to inform our event identification techniques. To identify events in social media, we follow two possible scenarios. In one scenario, we do not have any information about the events that are re ected in the data. In this scenario, we use an online clustering framework to identify these unknown events and their associated social media documents. To distinguish between event and non-event content, we develop event classification techniques that rely on a rich family of aggregate cluster statistics, including temporal, social, topical, and platform-centric characteristics. In addition, to tailor the clustering framework to the social media domain, we develop similarity metric learning techniques for social media documents, exploiting the variety of document context features, both textual and non-textual. In our alternative event identification scenario, the events of interest are known, through user-contributed event aggregation platforms (e.g., Last.fm events, EventBrite, Facebook events). In this scenario, we can identify social media documents for the known events by exploiting known event features, such as the event title, venue, and time. While this event information is generally helpful and easy to collect, it is often noisy and ambiguous. To address this challenge, we develop query formulation strategies for retrieving event content on different social media sites. Specifically, we propose a two-step query formulation approach, with a first step that uses highly specific queries aimed at achieving high-precision results, and a second step that builds on these high-precision results, using term extraction and frequency analysis, with the goal of improving recall. Importantly, we demonstrate how event-related documents from one social media site can be used to enhance the identification of documents for the event on another social media site, thus contributing to the diversity of information that we identify. The number of social media documents that our techniques identify for each event is potentially large. To avoid overwhelming users with unmanageable volumes of event information, we design techniques for selecting a subset of documents from the total number of documents that we identify for each event. Specifically, we aim to select high-quality, relevant documents that re ect useful event information. For this content selection task, we experiment with several centrality-based techniques that consider the similarity of each event-related document to the central theme of its associated event and to other social media documents that correspond to the same event. We then evaluate both the relative and overall user satisfaction with the selected social media documents for each event. The existing tools to find and organize social media event content are extremely limited. This dissertation presents robust ways to organize and filter this noisy but powerful event information. With our event identification, characterization, and content selection techniques, we provide new opportunities for exploring and interacting with a diverse set of social media documents that re ect timely and revealing event content. Overall, the work presented in this dissertation provides an essential methodology for organizing social media documents that re ect event information, towards improved browsing and search for social media event data.

Modelling life trajectories and mode choice using Bayesian belief networks

Probing life scripts for important life events in a multi-ethnic society

Modern computer architectures have evolved from uni-processor platforms to multi-processor and multi-core platforms, but traditional real-time distributed middleware such as RT-CORBA has not kept pace with that evolution. To address those issues, this paper describes the design and implementation of MCFlow, a new real-time distributed middleware for dependent task graphs running on multi-core platforms. MCFlow provides the following contributions to the state of the art in real-time middleware: (1) it provides an efficient C++ based component model through which computations can be configured flexibly for execution within a single core, across cores of a common host, or spanning multiple hosts; (2) it allows optimizations for inter-component communication to avoid data copying without sacrificing the parallel executability of data dependent tasks; (3) it strictly separates timing and functional concerns of an application so that they can evolve and can be configured independently; and (4) it provides a novel event dispatching architecture that uses lock free algorithms to avoid mutex locking and reduce memory contention, CPU context switching, and priority inversion. We also present an empirical evaluation that demonstrates the efficacy of our approach. Type of Report: Other Department of Computer Science & Engineering Washington University in St. Louis Campus Box 1045 St. Louis, MO 63130 ph: (314) 935-6160 The Design and Implementation of MCFlow: a Real-time Multi-core Aware Middleware for Dependent Task Graphs Huang-Ming Huang, Christopher Gill, Chengyang Lu Department of Computer Science and Engineering, Washington University St. Louis, MO, USA {hh1, cdgill, lu}@cse.wustl.edu Abstract—Modern computer architectures have evolved from uni-processor platforms to multi-processor and multi-core platforms, but traditional real-time distributed middleware such as RT-CORBA has not kept pace with that evolution. To address those issues, this paper describes the design and implementation of MCFlow, a new real-time distributed middleware for dependent task graphs running on multi-core platforms. MCFlow provides the following contributions to the state of the art in real-time middleware: (1) it provides an efficient C++ based component model through which computations can be configured flexibly for execution within a single core, across cores of a common host, or spanning multiple hosts; (2) it allows optimizations for inter-component communication to avoid data copying without sacrificing the parallel executability of data dependent tasks; (3) it strictly separates timing and functional concerns of an application so that they can evolve and can be configured independently; and (4) it provides a novel event dispatching architecture that uses lock free algorithms to avoid mutex locking and reduce memory contention, CPU context switching, and priority inversion. We also present an empirical evaluation that demonstrates the efficacy of our approach.Modern computer architectures have evolved from uni-processor platforms to multi-processor and multi-core platforms, but traditional real-time distributed middleware such as RT-CORBA has not kept pace with that evolution. To address those issues, this paper describes the design and implementation of MCFlow, a new real-time distributed middleware for dependent task graphs running on multi-core platforms. MCFlow provides the following contributions to the state of the art in real-time middleware: (1) it provides an efficient C++ based component model through which computations can be configured flexibly for execution within a single core, across cores of a common host, or spanning multiple hosts; (2) it allows optimizations for inter-component communication to avoid data copying without sacrificing the parallel executability of data dependent tasks; (3) it strictly separates timing and functional concerns of an application so that they can evolve and can be configured independently; and (4) it provides a novel event dispatching architecture that uses lock free algorithms to avoid mutex locking and reduce memory contention, CPU context switching, and priority inversion. We also present an empirical evaluation that demonstrates the efficacy of our approach. Keywords-component; middleware

Diagnosability is the property of a given partially observable system model to always exhibit unambiguously a failure behavior from its only available observations in finite time after the fault occurrence, which is the basic question that underlies diagnosis taking into account its requirements at design stage. However, for the sake of simplicity, the previous works on diagnosability analysis of discrete event systems (DESs) have the same assumption that any observable event can be globally observed, which is at the price of privacy. In this paper, we first briefly describe cooperative diagnosis architecture for DESs with autonomous components, where any component can only observe its own observable events and thus keeps its internal structure private. And then a new definition of cooperative diagnosability is consequently proposed. At the same time, we present a formal framework for cooperative diagnosability checking, where global consistency of local diagnosability analysis can be achieved by analyzing communication compatibility between local twin plants without any synchronization. The formal algorithm with its discussion is provided as well.

Smartphone is chosen as a tool to implement information system of solo culture event due to observation in Solo city that shows that smartphone is owned by all people good from among children up to parents. Information Systems Solo Based Android Culture Event to provide information about events or events for the people of Solo city and tourists outside the city of Solo and as a medium of cultural promotion both national and international scale. Information Systems Solo Based Android Culture Event, built using descriptive method with the type of case study research in the city of Surakarta. Techniques of system weakness analysis using PIECES analysis (Perfomance, Information, Economy, Cotrol, Efficiency, and Service). For system development techniques using waterfall method, while to describe the data flow using Data Flow Diagram consisting of context diagram, Data Flow Diagram level 0 and Data Flow Diagram Level 1. Software used to build this system is Android Studiodan XAMPP as MySQL database connection . Based on testing that has been done using blackbox testing, the built system can help the problems faced Solo tourism office and Solo city tourists. Keywords: Cultural Event, Event Information System Android Based Culture, Android Studio, XAMPP

Complete formal verification of a non-trivial concurrent OS kernel is widely considered a grand challenge. We present a novel compositional approach for building certified concurrent OS kernels. Concurrency allows interleaved execution of kernel/user modules across different layers of abstraction. Each such layer can have a different set of observable events. We insist on formally specifying these layers and their observable events, and then verifying each kernel module at its proper abstraction level. To support certified linking with other CPUs or threads, we prove a strong contextual refinement property for every kernel function, which states that the implementation of each such function will behave like its specification under any kernel/user context with any valid interleaving. We have successfully developed a practical concurrent OS kernel and verified its (contextual) functional correctness in Coq. Our certified kernel is written in 6500 lines of C and x86 assembly and runs on stock x86 multicore machines. To our knowledge, this is the first proof of functional correctness of a complete, general-purpose concurrent OS kernel with fine-grained locking.

Traditional fixed-priority scheduling analysis for periodic/sporadic task sets is based on the assumption that all tasks are equally critical to the correct operation of the system. Therefore, every task has to be schedulable under the scheduling policy, and estimates of tasks' worst case execution times must be conservative in case a task runs longer than is usual. To address the significant under-utilization of a system's resources under normal operating conditions that can arise from these assumptions, several mixed-criticality scheduling approaches have been proposed. However, to date there has been no quantitative comparison of system schedulability or run-time overhead for the different approaches. In this dissertation, we present what is to our knowledge the first side-by-side implementation and evaluation of those approaches, for periodic and sporadic mixed-criticality tasks on uniprocessor or distributed systems, under a mixed-criticality scheduling model that is common to all these approaches. To make a fair evaluation of mixed-criticality scheduling, we also address some previously open issues and propose modifications to improve schedulability and correctness of particular approaches. To facilitate the development and evaluation of mixed-criticality applications, we have designed and developed a distributed real-time middleware, called MCFlow, for mixed-criticality end-to-end tasks running on multi-core platforms. The research presented in this dissertation provides the following contributions to the state of the art in real-time middleware: (1) an efficient component model through which dependent subtask graphs can be configured flexibly for execution within a single core, across cores of a common host, or spanning multiple hosts; (2) support for optimizations to inter-component communication to reduce data copying without sacrificing the ability to execute subtasks in parallel; (3) a strict separation of timing and functional concerns so that they can be configured independently; (4) an event dispatching architecture that uses lock free algorithms where possible to reduce memory contention, CPU context switching, and priority inversion; and (5) empirical evaluations of MCFlow itself and of different mixed criticality scheduling approaches both with a single host and end-to-end across multiple hosts. The results of our evaluation show that in terms of basic distributed real-time behavior MCFlow performs comparably to the state of the art TAO real-time object request broker when only one core is used and outperforms TAO when multiple cores are involved. We also identify and categorize different use cases under which different mixed criticality scheduling approaches are preferable.

Study with the title “ Income Distribution and The Factors that Influence toward Low Economic Society on Kedungbanteng District, Banyumas” case study on low economic family that receive Woman Loan System (Simpan Pinjam Perempuan) at District Development Program. The aims of this research is to determine and analyze income distribution and factors that influence of its. This reasect use survey method toward three villages as sample, which are have the furthermost distance from central district (Melung village), middle (Karangnangka village), and the nearest (Kedungbanteng village). The respondent is society, specifically woman that receive Woman Loan System (Simpan Pinjam Perempuan) at District Develompent Program. This research is quantitative descriptive analyzing and used gini index and double linear regression. The result of analysis shows that Income distribution from business activity who have receive loan woman system shows that Karangnangka and Melung classified into low rate of imbalance distribution, otherwise Kedungbanteng classified into high rate imbalance distribution and holistically imbalance distribution on Kedungbanteng include in high rate. Based on regression coefficient factor that have influence mostly in order are long time of business, education, and loan capital, family dependent do not influence toward rate of income. This research suggest to handling event to empower the knowledge, such as entrepreneur skill and the parties that should be more selective when giving loan business. Keywords: District Development Program , ProgramSimpan Pinjam Perempuan, gini index,

The European Union Reference Laboratory for Genetically Modified Food and Feed (EU-RL GMFF), accredited under ISO/IEC 17043, organised a comparative testing (CT) round for National Reference Laboratories (NRLs) nominated under Regulation (EC) No 882/2004, with voluntary participation of other official control laboratories.\nThe test items consisted of rice noodles and commercial soybeans spiked with ground powder of soybean event DP-356043-5 in two different concentrations (Level 1 and 2). Participants were required to perform species identification and test for the presence of any GM event in the two test items. Any event detected then had to be quantified. Participants could report the results in mass/mass % or copy/copy % and the EU-RL GMFF calculated the robust means (R) for Level 1 and 2 test items accordingly. The target standard deviation for CT was fixed by the Advisory Board for Comparative Testing at 0.2 for the event, based on the experience of previous CT rounds. The robust means and target standard deviation were used to derive z-scores for the participants’ results. \nEighty-eight laboratories from 42 countries registered for this CT round, of which 85 laboratories from 41 countries returned at least qualitative test results. \nWhen performing species identification, almost all laboratories correctly identified soybean and rice in both test items, and a few laboratories also detected maize and/or oilseed rape. In total 71 laboratories reported the presence of GM material in the test items, but 14 laboratories failed in this task. All of the 71 laboratories, except eight, correctly identified soybean event DP-356043-5 in the test items.\nResults of the quantitative evaluation of the GM content were satisfactory for both measurement units, with only two NRLs appointed under Regulation (EC) No 1981/2006 (one measuring in m/m % and one in cp/cp %) obtaining unsatisfactory z-scores (|z| ≥ 2.0) for both test items. \nDespite the overall satisfactory outcome of this CT round, only 58 % of participants provided information on measurement uncertainty in a complete and consistent manner, and further improvement in this crucial area is needed.

Natural and Anthropogenic Drivers of Water Quality in the Normanby Basin and Princess Charlotte Bay, Cape York Peninsula, Australia

O aumento nas demandas por gerenciamento, controle e monitoramento das informacoes na area da automacao hospitalar tem promovido um maior volume de pesquisas que sao indutoras do processo de inovacao tecnologica na area da saude. Neste contexto, um aspecto considerado importante na automatizacao do monitoramento de pacientes consiste na eficiencia em detectar e informar em tempo habil as anomalias encontradas nos sinais vitais dos pacientes. O procedimento de notificar as ocorrencias dessas anomalias a equipe medica pode ser implementado por meio da geracao e envio de alertas (sonoros ou visuais). Verificando a relevância desse tipo de demanda no ambiente hospitalar, o presente artigo descreve uma arquitetura que tem como fundamento a geracao e o envio de alertas, cujos dados sao advindos de pacientes internados em Unidades de Terapia Intensiva (UTI). A premissa foi, portanto, otimizar o processo de comunicacao das anomalias detectadas de modo que a equipe medica responsavel seja notificada de tais eventos de maneira mais eficiente. A arquitetura de comunicacao, definida para o ambiente hospitalar, baseou-se em estudos realizados na UTI do Hospital Universitario Onofre Lopes (HUOL). Tais estudos possibilitaram uma analise de requisitos que permitiu definir um gerador de alertas personalizados, e o envio desses para dispositivos moveis das equipes medicas. O processo de envio dos alertas foi baseado em um algoritmo de escalonamento de tempo real, fazendo uso de um middleware e de computacao movel e distribuida, sendo esses os aspectos inovadores dessa arquitetura.

Background: Many signs in relation to vascular events and consequent loss of consciousness could be easily incorrectly explained (unclear) in a setting of trauma, especially when these events are a result of the car accident. Third cranial nerve palsy widely occurs due to internal carotid and posterior communicating artery aneurysm. An anterior communicating(ACOM) aneurysm is a rare reason that could lead to oculomotor dysfunction. ACOM ruptured aneurysm may present with sub arachnoid hemorrhage (SAH) and intraventricular hemorrhage (IVH) but isolated IVH is a rare finding for ACOM ruptured aneurysm. Case Description: A 56-year-old male presented to the hospital emergency department because of trauma after a car accident. He was unconscious with left-sided dilated pupil and ptosis with a brain CT indicating IVH. Brain CT angiography that performed two weeks after the accident revealed ACOM aneurysm. The patient underwent craniotomy and clipping the aneurysm. He was discharged, after completing the period of the following treatmentA combination of neuropathic agents and opioids helped to control pain. These analgesic included amitriptyline, gabapentin, pregabalin, tramadol and morphine in various regimens. Paracetamol and ibuprofen were also used. Conclusion: This report is a unique case of synchronization of third cranial nerve palsy and isolated IVH without SAH due to ACOM aneurysm. In addition, it could be interesting to re-emphasize the need for a comprehensive assessment of traumatic patients for finding some primary pathologies, which could result in an accident.

Jeff Magee and Jeff Kramer John Wiley and Sons, New York, NY, 1999, 374 pp. ISBN 0471987107, $64.99 The book is an introductory text to the ideas, concepts, and topics of concurrency. The text focuses on understanding concepts and techniques, and problems of concurrency, not on the implementation or language. The author's overall goal is that by a combination of learning and doing using Java should make the process of acquiring the skills relating to concurrency interesting, enjoyable, and challenging. The Java language is thus used only for illustration and programming experience of the reader. The book is intended for a computer science student or software developer. A background in programming is expected, as well as some familiarity with the essential concepts of object-oriented programming. Knowledge of the Java programming language and operating systems concepts is beneficial but not required. After reading the text, a reader can expect to have a broad understanding of the concepts of concurrency, the problems that arise, methods to emphasis desirable properties in a concurrent system, and ways to avoid the undesirable ones. The text provides a systematic treatment of concepts, as means to rigorously specify and model concurrent systems, with Java examples to animate and illustrate the concepts discussed. The book is organized into twelve chapters, with three appendices. The first eight chapters provide a concise and comprehensive foundation of concurrency, with the remaining four chapters focusing on more advanced concepts. The latter four chapters are somewhat supplemental and can be read at the discretion of the reader. The content of the text is self-contained, with no reliance upon external references. The authors provide a concluding set of notes and further topics which reference external works, but these are not used in the chapter contents. The introduction provides the foundation for the book, and an idea of what will follow in the rest of the text. The basics of modeling and Java are covered. Authors follow with the concepts of processes, threads and with the idea of concurrency. The emphasis is on using Java, and on the notation used to define a concurrent process or thread. The discussion continues covering interleaving and asynchronous concurrency. Various details about composition of parallel processes and finite state processing modeling are presented. The programming of concurrent execution using Java is then examined via the concept of multiple threads. Here, sharing objects among Java threads is also discussed. The concept of conditional synchronization is covered next, and is used to construct a monitor. The methods of the base object in Java is used, and a waiting queue associated with a Java object is discussed and implemented. This discussion is followed by introduction of deadlock. Authors show the conditions necessary for a deadlock to occur and present an analysis of a concurrent system establishing that such a system is deadlock-free. The classic Dining Philosopher's problem is used to illustrate the distinction between finding deadlocks in models and in programs. The presentation continues with the safety property (that asserts that nothing bad happens), and the liveliness property (that asserts that nothing good happens). Here, authors use the material on model-based design to consolidate many of the concepts previously discussed. No one modeling method or design methodology is emphasized. Then creation and elimination of threads in a running program is covered next. The dynamic starting and stopping of Java threads is presented. The discussion moves then to messaging passing. Asynchronous and synchronous messaging is presented with Java programming examples. The concept of a rendezvous, allowing for interaction in a messaging system, is also presented. Based on the concepts developed so far filter-pipeline, supervisor-worker, and announcer-listener concurrent architectures are examined. Java programs demonstrating how the elements of each model interact at runtime are developed. The presentation completes with modeling and implementing of timed systems. Time is signaled by the passage of successive time ticks. The authors then elaborate on a system that is event-based rather than thread-based. Java programs are used to illustrate in implementation the concepts discussed. The three appendices provide a reference, specification, and listing of semantics for the finite-state modeling algebra used by the authors throughout the book. The text is ideal for teaching in a classroom environment, or for a motivated reader to use for self-paced learning. Its organization follows a logical train of discussion and thought, with each chapter building successively on the other, with the more difficult concepts and topics withheld until later. This gradual approach makes the material flow smoothly and cohesively from the beginning to the end. The book is intended as a textbook, so does organize the material and discussion as one, but does not become too dry or bland to stifle the reader's interest in the material. The examples are inter-mixed with the discussion to highlight and emphasize essential points the authors make in each chapter. The text illustrates concepts well under discussion, and does not become a long-winded recital of theory. The topics examined are fundamental to concurrency, and are well illustrated and discussed, but no one topic is examined extensively. The code examples are well written concerning the programming style, indentation and comments. A CD is provided, containing the codes from the book. In addition supplementary material consisting of presentation slides and an errata is provided on the author's WWW site, as well as on the CD. The book is up to date both on the topics of concurrency, and with the Java applets, code, and programs used to illustrate them. Later, as the Java language evolves, the examples may need to be updated, but for the time being the text well represents that state of the Java language. William F. Gilreath, Micron Technology, Inc., Boise Idaho