Top PDF Operating Systems and Middleware: Supporting Controlled Interaction

Operating Systems and Middleware: Supporting Controlled Interaction

Operating Systems and Middleware: Supporting Controlled Interaction

This point is worth emphasizing. Although the system’s state remains consistent as though only one transaction were executed at a time, transac- tions in fact execute concurrently, for performance reasons. The transaction system is responsible for maintaining atomicity in the face of concurrency. That is, it must ensure that transactions don’t interact with one another, even when running concurrently. Often the system will achieve this isolation by ensuring that no transaction reads from any data object being modified by another transaction. Enforcing this restriction entails introducing syn- chronization that limits, but does not completely eliminate, the concurrency. In Section 5.2, I will sketch several examples of the ways in which transac- tions are used by middleware and operating systems to support application programs. Thereafter, I present techniques used to make transactions work, divided into three sections. First, Section 5.3 explains basic techniques for ensuring the atomicity of transactions, without addressing durability. Sec- ond, Section 5.4 explains how the mechanism used to ensure failure atomic- ity can be extended to also support durability. Third, Section 5.5 explains a few additional mechanisms to provide increased concurrency and coor- dinate multiple participants cooperating on a single transaction. Finally, Section 5.6 is devoted to security issues. The chapter concludes with exer- cises, exploration and programming projects, and notes.
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Operating Systems and Middleware pdf

Operating Systems and Middleware pdf

This point is worth emphasizing. Although the system’s state remains consistent as though only one transaction were executed at a time, transac- tions in fact execute concurrently, for performance reasons. The transaction system is responsible for maintaining atomicity in the face of concurrency. That is, it must ensure that transactions don’t interact with one another, even when running concurrently. Often the system will achieve this isolation by ensuring that no transaction reads from any data object being modified by another transaction. Enforcing this restriction entails introducing syn- chronization that limits, but does not completely eliminate, the concurrency. In Section 5.2, I will sketch several examples of the ways in which transac- tions are used by middleware and operating systems to support application programs. Thereafter, I present techniques used to make transactions work, divided into three sections. First, Section 5.3 explains basic techniques for ensuring the atomicity of transactions, without addressing durability. Sec- ond, Section 5.4 explains how the mechanism used to ensure failure atomic- ity can be extended to also support durability. Third, Section 5.5 explains a few additional mechanisms to provide increased concurrency and coor- dinate multiple participants cooperating on a single transaction. Finally, Section 5.6 is devoted to security issues. The chapter concludes with exer- cises, exploration and programming projects, and notes.
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Android Operating Systems

Android Operating Systems

Android is a software platform and operating system for mobile devices, based on the Linux kernel, and developed by Google and later the Open Handset Alliance. It allows developers to write managed code in the Java language, controlling the device via GoogledevelopedJava libraries. Android is available as open source. Android is freely downloadable open source software stack for mobile devices that includes an operating system, middleware and key applications based on Linux and Java. Google purchased the developer of Android in 2005, and Android was unveiled in 2007. Google released the Android code as open- source under the Apache License. Android has numerous developers writing applications (apps) all over the world. First of all the developers write their script in Java, and then download heaps from the third party sites or online stores. In February 2012, 450,000 appeared available for Android but the estimated number of downloads since December, 2011 was more than 10billion. There are over 300 million Androids in use and over 850,000devices activated every day. Android is the one of the most used mobile operating system with a market share of48% and over 400,000 applications available in Google play store. Android apps have been installed over 10 billion times and cover a vast range of categories from games and entertainment to financial and business services. Android software development and the Google Play Market are relatively open and unrestricted. This offers both developers and users more flexibility and freedom, but also creates significant security challenges.
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Middleware Challenges for Cyber-Physical Systems

Middleware Challenges for Cyber-Physical Systems

7. Current Research Efforts. There is some ongoing research to customize existing middleware plat- forms or design new middleware services to fit with the CPS challenges. One of these important challenges is supporting real-time operations in CPS. Real-time support requires provisions from the operating systems, resource managers and networks. The requirements and an architecture for a CPS middleware supporting these provisions was proposed in [31]. In addition, different real-time challenges for diverse scenarios were proposed. An example of these proposals is the approach to solve the real-time issue for aperiodic events in distributed CPS using a reconfigurable real-time middleware [82]. Another proposal is RDDS which is a publish/subscribe- mid- dleware architecture developed to enable timely and reliable sensor data dissemination in highly unpredictable CPS environments [42]. There are also some research efforts dedicated to address the heterogeneity challenges in CPS. A middleware that provides interoperability between heterogeneous mobile devices in CPS was proposed in [76]. Furthermore, developing portable middleware services for heterogeneous CPS was proposed in [55]. Other research efforts were conducted to investigate reliability, security, safety, and fault tolerance in CPS. As an example, the main role of middleware in facilitating robust and resilient CPS was studied in [27] while a re- liable, safe, and secure run-time platform for CPS was proposed in [51]. Moreover, a time-triggered middleware architecture that offers fault tolerance and dynamic reconfiguration at run-time taking into consideration the available system resources of the underlying infrastructure was proposed in [61].
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Reconfigurable Component based Middleware for Networked Embedded Systems

Reconfigurable Component based Middleware for Networked Embedded Systems

Next generation embedded systems will be composed of large numbers of heterogeneous devices. These will typically be resource-constrained (such as sensor motes), will use different operating systems, and will be connected through different types of network interfaces. Ad- ditionally, they may be mobile and/or form ad-hoc networks with their peers, and will need to be adaptive to changing conditions based on context-awareness. Our focus in this paper is on the provision of a middleware framework for such system environments. Our approach is based on a small and efficient ‘middleware kernel’ which supports highly modularised and customisable component-based middleware services that can be tailored for specific embed- ded environments, and are runtime reconfigurable to support adaptivity. These services are primarily communications-related but also address a range of other concerns including service discovery and logical mobility. In the paper we provide an overview of our approach, focus- ing in detail on both the middleware kernel and the services. We also discuss an application scenario in which we are currently applying and evaluating our middleware approach.
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Interaction of leading and supporting factors for the SME competitiveness

Interaction of leading and supporting factors for the SME competitiveness

The main goal of this research was to reveal the SMEs competitiveness factors in terms of context specific (leading) and supporting factors. Precisely, the goal was to establish to what degree, and in which ways, these two groups of factors influence the SMEs performance under crisis economic conditions. The measures of competitiveness ranged from simple indicators to complex indexes (Buzzigoli and Viviani, 2009). The situation with Bulgarian SMEs was analyzed through the prism of 8 key factors. Five of these factors were compound variables, represented by indexes: (1) innovations; (2) internationalization; (3) own trademarks and patents; (4) access to finance; and (5) good management practices. The other three factors were implemented quality standards, export orientation, and size. Following the Porter idea about two types of competitive advantages, the factors were separated into two groups. The first group included factors for achieving sustainable competitive advantages (leading factors), while the second group contained supporting factors. Here we included the ICT and e-business adoption factor in “good management practices”, and not as separate leading factor. These groups of factors formed the conceptual model (Fig. 1).
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Mission-oriented middleware for sensor-driven scientific systems

Mission-oriented middleware for sensor-driven scientific systems

For most systems, programming abstractions are composed using static layering where each layer presents new, ex- tended, or simplified concepts in terms of those provided in the layers below. This can lead to redundancy and con- ceptual mis-match that, while acceptable on larger systems, become problematic when the abstractions are fundamen- tally inappropriate—for example by abstracting over fail- ure, which prevents applications from dealing with such fail- ures intelligently. It is possible to adopt a more modern, component-oriented approach to systems in which individ- ual features are defined independently along with statements of the dependencies and provided services. This principle can be applied to applications and device drivers—but also to protocol handlers, and even programming languages and type systems.
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36 / CAP TODAY March 2013 Middleware systems

36 / CAP TODAY March 2013 Middleware systems

Web services, file import/export, ODBC, others HL7 (all versions below 3.0), ANSI, XML, ASTM, proprietary, CSV, flat file, direct database, others Low-level transport middleware supports to interface to instruments serial RS232, serial USB, TCP/IP, FTP, LAT serial RS232, serial USB, TCP/IP, FTP, ODBC, others serial RS232, serial USB, TCP/IP, FTP, flat file Middleware can send results to and receive orders from reference labs yes (Quest, LabCorp) yes (Quest, LabCorp, ARUP, Mayo Clinic, others) yes (LabCorp, Quest, Specialty Laboratories, AML) LIS/HIS/EMR interfaces for receiving orders Sunquest, GE Healthcare, Siemens, NextGen,
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Comparison of Mobile Operating Systems

Comparison of Mobile Operating Systems

Technology is getting really advanced now-a-days and it is also becoming the most important part of our lives. In the early years mobiles phones were only capable of sending and receiving text messages and calls for communication purposes. However, times have changed and so has the face of mobile phones. Not only are the screens bigger and better in quality, but also is the internal hardware grown to such an extent that it can perform on levels in laptops and computers. Guess it is safe to call mobile phones a handheld computer that is able to configure daily schedules, save large documents, watch videos online, listen to music, use the internet and much more than the human mind can think of. Today smartphones carry all the features of a digital device as well as common phone features. As we can see, over the decade, smartphones have taken the world by storm, and recently tablets have entered the arena as well. Smart phones have transformed the way we access information and communicate with others. This not only depends on the device hardware but basically on the software these devices can run and especially their operating systems. Now, there is a lot of fanfare when it comes to which mobile OS is the best. Following are a few common facts that come handy to a buyer when he/she is at the brink of buying a smartphone:
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Resilient dependable cyber-physical systems: a middleware perspective

Resilient dependable cyber-physical systems: a middleware perspective

The latter aspect is gaining importance and presents many interesting opportunities for middleware-driven orchestra- tion of CPS. For example, knowledge of how a building fire is propagating (extracted from multiple sensory feeds) can enable better deployment of firefighter resources. A second interesting observation is that in many of the above CPSs, there is an increased use of a human-in-the-loop (in lieu of the completely automated approach), where CPS sys- tems provide situational awareness to humans who are de- cision makers. For example, power grid systems have hu- mans that control usage; operators that control distribution and even control generation (reselling of power generated by solar panels back to the grid). Similarly, healthcare ap- plications involve patients, doctors, nurses; individuals— all of which can impact how information is obtained and processed. Transportation systems have drivers with behav- iors that control low-level braking behavior in cars; or user travel patterns that create congestion. Emergency response systems are inherently a human-oriented process where in- dividuals in response agencies, onsite first responders, and citizens make decisions that can save lives and property. Such systems are especially interesting since they are com- plex heterogeneous networked systems with humans and (autonomous) agents in the loop—this brings about so- ciotechnical issues in the deployed cyber-physical systems. A third observation is that the information used in CPS en- vironments is increasingly multimodal in nature with di- verse data types (small sensor readings, images, video, au- dio/speech, text, and social media). Information may be structured (e.g., relational tables), unstructured (free form text) or semistructured (spatiotemporally tagged event data). This trend presents both an opportunity (due to the rich na- ture of the information) and challenge (added complexity due to volume of data and real-time processing needs).
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Deploying a middleware architecture for next generation mobile systems

Deploying a middleware architecture for next generation mobile systems

In this work, Bluetooth has been selected as a sample wireless interface in a testbed. A middleware based architecture is described and demonstrated on the testbed, but may well be implemented on other wireless platforms. This serves to illustrate some aspects of next generation networks and services. It will be a win-win situation both for application developers (including third party developers), hardware vendors and users alike. Although Bluetooth has a short transmission range, for most of the services described or expected, this distance is adequate. [6] describes a successful deployment of specific services over Bluetooth, but only provided access to local services, and was for the Bluetooth interface only. This paper in contrast examines an architecture for deploying services over any short range wireless platform, Bluetooth has only been used as a sample for demonstration. First, an overview of next generation services is given, followed by a description of the testbed, and the proposed architecture. A sample deployment, together with the software is examined, and lessons therefrom are outlined in the conclusion. It is shown that middleware can be employed to abstract the wireless interface, while integrating distributed service components.
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RAFDA : A policy aware middleware supporting the flexible separation of application logic from distribution

RAFDA : A policy aware middleware supporting the flexible separation of application logic from distribution

In contrast to conventional middleware systems, in order to expose an instance of a class using the RRT, it is not necessary that the class implement any special interfaces or extend any special classes. Objects can be exposed to remote access using any interface with which they are structurally compliant. Thus the application programmer can implement the classes providing core application functionality without regard for the remote accessibility of the instances of those classes. Decisions about the remote accessibility of a particular object can be delayed until much later in the design cycle, even until run-time. Monitoring and management infrastructure that views and controls application state from another address space can be created without modification, or even access, to the application’s original source code.
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Advanced Operating Systems CS428

Advanced Operating Systems CS428

ParallelList(L,"f",S); runs through the elements of the list L and, for each element x , waits until some process in S is available for computation; it then requests this process[r]

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INF 2 Operating systems

INF 2 Operating systems

In protected mode, programs may have access to a more limited set of the CPU's instructions. A user program may leave protected mode only by triggering an interrupt, causing control to be passed back to the kernel. In this way the operating system can maintain exclusive control over things like access to hardware and memory.

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Role of Agent Middleware in Teaching Distributed Systems and Agent Technologies

Role of Agent Middleware in Teaching Distributed Systems and Agent Technologies

Before concluding the discussion on educa- tional experiences with DNAD course at the University of Craiova, we mention that, start- ing with 2016, the CS curricula was updated according to new regulations and, although quite successful in our opinion, the topics of the DNAD course had to be dispersed into oth- er courses, as follows. Firstly, the course itself was shifted one semester earlier and it was oriented more on concurrent programming in- cluding modeling and verification of concur- rency, as well as on programming with threads on multicore architectures, with examples in Java. Only a small part related to the introduc- tion of distributed systems and programming by asynchronous message passing using sock- ets and remote method invocation, was kept in the new course. More advanced distributed computing aspects, including distributed and parallel algorithms are now being taught as a separate course. Multi-agent systems topics were also included into an advanced course that is taught within the Master program. However, the aim of this course is more in the spirit of multi-agent, than distributed systems, including, for example, topics of game theory, artificial intelligence (Belief-Desire-Intention programming) and Machine Learning. Note also that an advanced course on Distributed Programming focused on distributed software technologies is also included in the Master program. So, we can conclude that our posi- tive experiences with teaching DNAD topics were not lost, but rather reused by enriching other courses that are now part of the CS cur- ricula at the University of Craiova.
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Research in Operating Systems Sparrow

Research in Operating Systems Sparrow

Sparrow provides response times for short tasks within 11% of ideal (100ms) when running on 16-core machines, even when 50% of tasks are 3 orders of mag- nitude longer. When 50% of tasks[r]

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The Design of Real Time Operating Systems for Embedded Systems

The Design of Real Time Operating Systems for Embedded Systems

Each programs need to held in a memory generally in a ROM to be executed. The task data (stack and registers) and all variables must be stored in RAM. In a real-time system the main requirement is that the access time should be bound or predictable. The use of demand paging is not allowed since the systems providing virtual memory mechanisms use memory swapping which is not predictable. RTOS have fast and predictable functions to allocate and free fixed size buffers. RTOS allows to setup pools each of which consist of same number of memory buffers. In any given pool all buffers are of same size. In many circumstances it is not acceptable for hardware failure to corrupt data in memory. In such instance hardware protection mechanism should be used. In Hard Real-time systems static memory allocation is used. In a Soft Real-time system dynamic memory allocation is preferred.
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Supporting Intergenerational Interaction: Affordance of Urban Public Space

Supporting Intergenerational Interaction: Affordance of Urban Public Space

Later defined in more detail by Robert Sommer (1969) in Personal Space, Hall’s final category of spatial experience included four distance or proxemic zones: intimate, personal, social, and public (Hall 1966). These personal space distances are especially noteworthy when discussing social interaction between youth and older adults and have relevance to their perceptions of the supportiveness of the urban spaces presented in the photo-questionnaire. Obviously, the intimate distance (0-1 ft.) is and should not be of interest to either member of the intergenerational pair as it reflects an unmistakable interconnection with another body. Both the personal and the social distances are directly related to interactions between the dyad. Thought of as a small protective bubble, personal distance was first denoted by Heniri Hediger (1968) to distances separating non-contact species. Hall divides this space into a far phase (2-4 ft.) and a close phase (1-2 ft.). At first, while the pair is getting to know each other, the far phase distance would seem most appropriate. Teaching, sitting, walking, and talking about generalities within a community open space does not require closer contact. But as the friendship develops, the close phase distance would support short personal contacts such as a hug for support or a jovial slap on the back. As trust grows, this close-in personal space can support conversations about issues of personal concern to each member of the pair.
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Supporting Workflow Management Systems with Traceability

Supporting Workflow Management Systems with Traceability

Workflow management is defined as the management of processes through the execution of software whose order of execution is controlled by a computerized representation of the process. The primary reason for the popularity of workflow technology is its support for the management trends including reinvention and revitalizing corporations through rightsizing and business-process reengineering. Current implementations of workflow systems such as Enterprise Resource Planning (ERP) systems automate core corporate activities and let companies share common data and practices across the enterprises. Workflow systems are designed to assist groups of people in carrying out work procedures, and contain organizational knowledge of where work flows. Workflow systems are defined as “ systems that help organizations to specify, execute, monitor, and coordinate the flow of work items in a distributed environment” [7]. A WFMS provides the software tools to define, manage and execute workflows. WFMS have two main functions: a build time function and a run time function. Build time functions enable businesses to model their business procedures and activities, using scripting language. Run time functions help administer workflow process and run
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Metadata Tools Supporting Controlled Vocabulary Services

Metadata Tools Supporting Controlled Vocabulary Services

2. Metadata Vocabulary Interoperability The availability of metadata on the Internet links together the producers and consumers of resources and creates “universal” metadata search spaces. The use of different metadata vocabularies can be considered as partitioning this universal space into a number of sub- spaces. Interoperability between such sub-spaces can only be achieved by carrying out mappings between the elements of the different MD vocabularies. Of course such mappings are lossy, i.e. relevant information will be lost or not carried over fully semantically correct. One key for the success in such mappings is the usage of well-defined CV’s for associating values with certain metadata elements. Of course it makes sense in various respects to use the same codes for elements of the different sets that share the same semantics such as for languages in all the different sets. The existence of various language encoding systems such as provided by ISO [3] and SIL [4], however, indicate that even with respect to controlled vocabularies mapping schemes have to be applied.
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