Distributed Computing

Virtualisation techniques are growing in popularity and importance, given their application to server consolidation and to cloud computing. Remote Attestation is a well-known technique to assess the software integrity of a node. It works well with physical platforms, but not so well with virtual machines hosted in a full virtualisation environment (such as the Xen hypervisor or Kernel-based Virtual Machine) and it is simply not available for a lightweight virtualisation environment (such as Docker). On the contrary, the latter is increasingly used, especially in lightweight cloud platforms, because of its flexibility and limited overhead as compared to virtual machines. This paper presents a solution for security monitoring of a lightweight cloud infrastructure, which exploits Remote Attestation to verify the software integrity of cloud applications during their whole life-cycle. Our solution leverages mainstream tools and architectures, like the Linux Integrity Measurement Architecture, the OpenAttestation platform and the Docker container engine, making it practical and readily available in a real-world scenario. Compared to a standard Docker deployment, our solution enables run-time verification of container applications at the cost of a limited overhead.

This paper gives a survey of the infrastructure currently being developed in the MUSITECH project. The aim of this project is to conceptualize and implement a computational environment for navigation and interaction in internet-based musical applications. This comprises the development of data models, exchange formats, interface modules and a software framework. Our approach is to integrate different information and media types like MIDI, audio, text based codes and metadata and their relations, especially to provide means to describe arbitrary musical structures. We attempt to connect different musical domains to support cooperations and synergies. To establish platform independence Java, Extensible Markup Language (XML), and other open standards are used. The object model, a framework and various components for visualization, playback and other common tasks and the technical infrastructure are being developed and will be evaluated within the project.

In 2005, Oak Ridge National Laboratory received delivery of a 5,294 processor Cray XT3. The XT3 is Cray's third-generation massively parallel processing system. The ORNL system uses a singleprocessor node built around the AMD Opteron and uses a custom chip-called SeaStar-for interprocessor communication. The system uses a lightweight operating system called Catamount on its compute nodes. This paper provides a performance evaluation of the Cray XT3, including measurements for microbenchmark, kernel, and application benchmarks. In particular, we provide performance results for strategic Department of Energy applications areas including climate, biology, astrophysics, combustion, and fusion. Our results, on up to 4,096 processors, demonstrate that the Cray XT3 provides competitive processor performance, high interconnect bandwidth, and high parallel efficiency on a diverse application workload, typical in the DOE Office of Science.

Increasingly users are seen as the weak link in the chain, when it comes to the security of corporate information. Should the users of computer systems act in any inappropriate or insecure manner, then they may put their employers in danger of financial losses, information degradation or litigation, and themselves in danger of dismissal or prosecution. This is a particularly important concern for knowledge-intensive organisations, such as Universities, as the effective conduct of their core teaching and research activities is becoming ever more reliant on the availability, integrity and accuracy of computer-based information resources. One increasingly important mechanism for reducing the occurrence of inappropriate behaviours, and in so doing, protecting corporate information, is through the formulation and application of a formal 'acceptable use policy (AUP). Whilst the AUP has attracted some academic interest, it has tended to be prescriptive and overly focussed on the role of the Internet, and there is relatively little empirical material that explicitly addresses the purpose, positioning or content of real acceptable use policies. The broad aim of the study, reported in this paper, is to fill this gap in the literature by critically examining the structure and composition of a sample of authentic policies -taken from the higher education sector -rather than simply making general prescriptions about what they ought to contain. There are two important conclusions to be drawn from this study: 1) the primary role of the AUP appears to be as a mechanism for dealing with unacceptable behaviour, rather than proactively promoting desirable and effective security behaviours, and 2) the wide variation found in the coverage and positioning of the reviewed policies is unlikely to be fostering a coherent approach to security management, across the higher education sector.

Computer vision algorithms are natural candidates for high performance computing systems. Algorithms in computer vision are characterized by complex and repetitive operations on large amounts of data involving a variety of data interactions (e.g., point operations, neighborhood operations, global operations). In this paper, we describe the use of the custom computing approach to meet the computation and communication needs of computer vision algorithms. By customizing hardware architecture at the instruction level for every application, the optimal grain size needed for the problem at hand and the instruction granularity can be matched. A custom computing approach can also reuse the same hardware by reconfiguring at the software level for different levels of the computer vision application. We demonstrate the advantages of our approach using Splash 2-a Xilinx 4010-based custom computer.

Over the last few years, IEEE 802.16 has been established as one of the most promising solutions for broadband wireless metropolitan area networks. In 2007, the standard was included as one of the radio access technologies for IMT-2000. The forthcoming version of the standard, IEEE 802.16m, is currently under evaluation by ITU as a radio technology for IMT-Advanced. In this paper we present a historical overview of the standard and provide a detailed technical discussion of the most relevant features introduced in the 2009 release and in the upcoming IEEE 802.16m. In particular, the downlink control signaling of these two versions is investigated in detail, and the results of a numerical analysis are illustrated for comparison purposes.

SIMAP is the abbreviated name for the Intelligent System for Predictive Maintenance. It is a software application addressed to the diagnosis in real-time of industrial processes. It takes into account the information coming in real-time from different sensors and other information sources and tries to detect possible anomalies in the normal behaviour expected of the industrial components. The incipient detection of anomalies allows for an early diagnosis and the possibility to plan effective maintenance actions. Also, the continuous monitoring performed allows for an estimation in a qualitative form of the health condition of the components. SIMAP is a general tool oriented to the diagnosis and maintenance of industrial processes, however the first experience of its application has been at a windfarm. In this real case, SIMAP is able to optimize and to dynamically adapt a maintenance calendar for a monitored windturbine according to the real needs and operating life of it as well as other technical and economical criteria. In particular this paper presents the application of SIMAP to the health condition monitoring of a windturbine gearbox as an example of its capabilities and main features.

Information governance as an approach to better govern the use of information within and outside an organization is rapidly gaining popularity. A common and scientific ground for this approach has not yet been formulated. In this article the authors describe a definition for information governance, extending the common, one-dimensional approach into a more generic statement. Starting from the well-known principles of IT governance the authors further explore the aspects of both information and governance. Four hypotheses are proposed to give ground to the use of information governance. These hypotheses will be the basis for further research.

Energy storage is a big problem today in the world for humanity depend on the challenges of conventional storage devices. So the researchers are studying to invent new energy storage devices and materials for many years. The supercapacitor (SC) is invented and presented as an alternating storage device recently. There were a lot of studies about SC in literature. These studies are focused on materials of SC components, modelling of SC, and applications of SC. In this paper, the working principle of SC, the advantages of SC, the classification of SC, and new developments of SC are investigated. Some material applications of SC are presented in this study also. The manufacturing developments are investigated for some SC materials and presented some novel applications also.

Introduction for second edition /  Preface

When in 1989 an anonymous reviewer commented on my short paper that “this classification should be extended to description of distributed systems,” (Yet another approach to classification of redundancy, CIM IMEKO Symp.1990, Helsinki, pp. 117-124) I was really excited, because people in the research community were thinking much deeper and wider than myself (- I had just defended my PhD).

Further, fault tolerance was migrating to dependability (Jean Claude Laprie was an indisputable authority and expert in this domain, see more:  www.springer.com/gb/book/9783709191729, which later emerged as the concept of resilience.

In principle, all these new properties had a concrete reasoning and meaning behind them: when something erroneous has happens, any system of our design should be able to cope with the problem. Options vary, as well as circumstances and area of application, thus:

- If it stops the error propagating and freezes in a safe state, it is fail-stop, or fail-safe;
- If it can cope with permanent faults inside the system, it is a fault tolerant system;
- When it continues with reduced functionality, it is graceful degradation;
- If it is designed with attention having been paid to reliability, availability and maintenance or serviceability, it is
      dependable system;
- If it capable to of tolerating obstacles caused by internal and external factors and can spring back, recover and continue, then a system can be considered as resilient.

There are two major ways to achieve any of the properties mentioned above: at  system level, or at local level (technological). Obviously, any reasonable combination of both levels is also welcome. In this book we do not want to repeat our papers and books
(https://www.springer.com/gb/book/9783319150680, https://www.springer.com/gb/book/9783319468129)
but to incorporate into the second edition any significant progress that has emerged.
Speaking about ICT systems, especially safety-critical and real-time ones, we might think about the implementation of resilience from the system level down through to hardware and systems software. In addition, we need to consider that each of the parts will both interact with and support each other.

NFRs (Non-Functional Requirements) of each part of the system were considered, such as:

- Performance;
- Reliability;
- Efficiency (mostly energy efficient).

Therefore, the systems that we design should be PRE-smart and provide these properties throughout the life cycle. 

Neither of  our books to date  - have appeared as complete. These books have been used in China, Switzerland, Russia and USA, (mostly Masters and PhD students) and we have received substantial feedback, such as:

- While reliability of hardware and availability at the system level are explained and fine, there are no sections, or chapters about performance, especially where parallel and distributed systems are concerned;
- How to apply (as mentioned in the above review) the classification and properties of resilience for and within distributed systems;
- How real-time and safety-critical applications should be treated considering the system resilience: rules for system and for packages - have they changed?

It was especially satisfying as  we have  discovered that these segments are being updated by researchers around the globe, providing excellent contributions to the content.

Thus, our book became and evolving system in itself, aggregating our further efforts with the efforts and results of our colleagues from China, Switzerland, UK and Russia. Our book has therefore become itself resilient, benefiting from the contributions from the following:

Performance chapter (including element level performance and parallel design was prepared and included using materials and having contributions from:

-  Professor Hao Kai, Shantou University, China;
- Simon Monkman, IT-ACS Ltd researcher.

System software chapters were part of substantial efforts from:

- Professor Eugeny Zuev and his team in Technopolis, Kazan, Russia.

In turn, requested in 1989 consideration of system level of resilience for distributed systems were developed as two chapters: system level and algorithmic implementation prepared by me and Stephen Farrell. In these chapters we have introduced a concept of desperation ( for transactions within distributed systems) and show that our existing and new results, even patented: https://www.ipo.gov.uk/p-ipsum/Case/PublicationNumber/GB2448351

can be extremely useful making the whole network really resilient and achieving by far better service for applications, especially when critical level of their use was assumed.

I Schagaev

Basic similarities among the several service-registry standards that exist today suggest the potential for interoperability. Given that service registries are key components inWeb services architectures, interoperability will play an increasingly important role in facilitating dynamic ...

Cloud computing offers an innovative business model to enterprise for IT services consumption and delivery. Software as a Service (SaaS) is one of the cloud offerings that attract organisations as a potential solution in reducing their IT cost. However, the vast diversity among the available cloud SaaS services makes it difficult for customers to decide whose vendor services to use or even to determine a valid basis for their selections. Moreover, this variety of cloud SaaS services has led to proprietary architectures and technologies being used by cloud vendors, increasing the risk of vendor lock-in for customers. Therefore, when enterprises interact with SaaS providers within the purview of the current cloud marketplace, they often encounter significant lock-in challenges to migrating and interconnecting cloud. Hence, the complexity and variety of cloud SaaS service offerings makes it imperative for businesses to use a clear and well understood decision process to procure, migrate and/or discontinue cloud services. To date, the expertise and technological solutions to simplify such transition and facilitate good decision making to avoid lock-in risks in the cloud are limited. Besides, little investigation has been carried out to provide a comprehensive decision framework to support enterprises on how to avoid lock-in risks when selecting and implementing cloud-based SaaS solutions within existing environments. Such decision framework is important to reduce complexity and variations in implementation patterns on the cloud provider side, while at the same time minimising potential switching cost for enterprises by resolving integration issues with existing IT infrastructures. This paper proposes a holistic 6-step decision framework that enables an enterprise to assess its current IT landscape for potential SaaS replacement, and provides effective strategies to mitigate vendor lock-in risks in cloud (SaaS) migration. The framework follows research findings and addresses the core requirements for choosing vendor-neutral interoperable and portable cloud services without the fear of vendor lock-in, and architectural decisions for secure SaaS migration. Therefore, the results of this research can help IT managers have a safe and effective migration to cloud computing SaaS environment.

Information governance as an approach to better govern the use of information within and outside an organization is rapidly gaining popularity. A common and scientific ground for this approach has not yet been formulated. In this article the authors describe a definition for information governance, extending the common, one-dimensional approach into a more generic statement. Starting from the well-known principles of IT governance the authors further explore the aspects of both information and governance. Four hypotheses are proposed to give ground to the use of information governance. These hypotheses will be the basis for further research.

Blockchain is a novel technology that is rising a lot of interest in the industrial and re- search sectors because its properties of decentralisation, immutability and data integrity. Initially, the underlying consensus mechanism has been designed for permissionless block- chain on trustless network model through the proof-of-work, i.e. a mathematical challenge which requires high computational power. This solution suffers of poor performances, hence alternative consensus algorithms as the proof-of-stake have been proposed.
Conversely, for permissioned blockchain, where participants are known and authenti- cated, variants of distributed consensus algorithms have been employed. However, most of them comes out without formal expression of security analysis and trust assumptions because the absence of an established knowledge. Therefore the lack of adequate analysis on these algorithms hinders any cautious evaluation of their effectiveness in a real-world setting where systems are deployed over trustless networks, i.e. Internet.
In this thesis we analyse security and performances of permissioned blockchain. Thus we design a general model for such a scenario in a way to propose a general benchmark for the experimental evaluations. This work brings two main contributions.
The first contribution concern the analysis of Proof-of-Authority, a Byzantine Fault- Tolerant consensus protocol. We compare two of the main algorithms, named Aura and Clique, with respect the well-established Practical Byzantine Fault-Tolerant, in terms of se- curity and performances. We refer the CAP theorem for the consistency, availability and partition tolerance guarantees and we describe a possible attack scenario in which one of the algorithms loses consistency. The analysis advocates that Proof-of-Authority for permissioned blockchains deployed over WANs experimenting Byzantine nodes, do not provide adequate consistency guarantees for scenarios where data integrity is essential. We claim that actually the Practical Byzantine Fault-Tolerant can fit better for permis- sioned blockchain, despite a limited loss in terms of performance.
The second contribution is the realisation of a benchmark for practical evaluations. We design a general model for permissioned blockchain under which benchmarking perfor- mances and security guarantees. However, because no experiment can verify all the pos- sible security issues permitted by the model, we prototype an adversarial model which simulate three attacks, feasible for a blockchain system. We then integrate this attacker model in a real blockchain client to evaluate the resiliency of the system and how much the attacks impact performances and security guarantees.

ÐEfficient and effective buffering of disk blocks in main memory is critical for better file system performance due to a wide speed gap between main memory and hard disks. In such a buffering system, one of the most important design decisions is the block replacement policy that determines which disk block to replace when the buffer is full. In this paper, we show that there exists a spectrum of block replacement policies that subsumes the two seemingly unrelated and independent Least Recently Used (LRU) and Least Frequently Used (LFU) policies. The spectrum is called the LRFU (Least Recently/Frequently Used) policy and is formed by how much more weight we give to the recent history than to the older history. We also show that there is a spectrum of implementations of the LRFU that again subsumes the LRU and LFU implementations. This spectrum is again dictated by how much weight is given to recent and older histories and the time complexity of the implementations lies between O(1) (the time complexity of LRU) and ylog P n (the time complexity of LFU), where n is the number of blocks in the buffer. Experimental results from trace-driven simulations show that the performance of the LRFU is at least competitive with that of previously known policies for the workloads we considered.

Dynamic decision problems constrained by time are of highly-interested in many aspects of real life. This paper proposes a new concept called the Dynamic Interval-valued Neutrosophic Set (DIVNS) for such the dynamic decision-making applications. Firstly, we define the definitions and mathematical operations, properties and correlations of DIVNSs. Next, we develop a new TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) method based on the proposed DIVNS theory. Finally, a practical application of the method for evaluating lecturers' performance at the

Responsiveness, the ability to provide real time behavior eveninpresence of faults, is becoming one of the most sought after properties in distributed computing systems. We present a framework for ''High-Performance Responsive Computing''i nn etworked systems whose current implementation works on a network of fiveN eXTSTEP (Mach 2.5)-based HP workstations. Within this paper we discuss the design issues behind the ''Unstoppable Orchestra''a nd showh ow our programming framework supports synchronization and re-configuration of responsive applications.

The purpose of this paper is creating a mobile app on a Smartphone device so that the user can control electronic devices; see the amount of flow that has been used in the amount of dollars, so the problem is the difficulty in saving electricity can be resolved. Development and design was done by collecting data using questionnaires to the respondents. Design method using observations, distributing questionnaires and to study literature, and then after that do the design in hardware (microcontroller) made United Modeling Language (UML), database design, code implementation and creation of user interfaces on IOS and Android. The result of this research is the implementation of a remote home automation application in mobile which can help users in order to control the home and determine the cost of electricity that has been used in every electronic device so that the optimization can be achieved.

We present the development and use of a novel distributed geohazard modeling environment for the analysis and interpretation of large scale earthquake data sets. Our work demonstrates, for the first time, how earthquake-related surface deformation measured from satellite images using imageodesy algorithms is coupled with analysis and simulation using finite-element numerical models.

The ability to describe business processes as executable models has always been one of the fundamental premises of workflow management. Yet, the tacit nature of human knowledge is often an obstacle to eliciting accurate process models. On the other hand, the result of process modeling is a static plan of action, which is difficult to adapt to changing procedures or to different business goals. In this article we attempt to address these problems by approaching workflow management with a combination of learning and planning techniques. Assuming that processes cannot be fully described at buildtime, we make use of learning techniques, namely Inductive Logic Programming (ILP), in order to discover workflow activities and to describe them as planning operators. These operators will be subsequently fed to a partial-order planner in order to find the process model as a planning solution. The continuous interplay between learning, planning and execution aims at arriving at a feasible plan by successive refinement of the operators. The approach is illustrated in two simple scenarios. Following a discussion of related work, the paper concludes by presenting the main challenges that remain to be solved.

The containment of power consumption and the use of alternative green sources of energy are the new main goals of telecommunication operators, to cope with the rising energy costs, the increasingly rigid environmental standards, and the growing power requirements of modern highperformance networking devices. To address these challenges, we envision the necessity of introducing energyefficiency and energy-awareness in the design, configuration and management of networks, and specifically in the design and implementation of enhanced control-plane protocols to be used in next generation networks. Accordingly, we focus on research and industrial challenges that foster new developments to decrease the carbon footprint while leveraging the capacities of highly dynamic, ultra-high-speed, networking. We critically discuss current approaches, research

Task intensive electronic control units (ECUs) in automotive domain, equipped with multicore processors , real time operating systems (RTOSs) and various application software, should perform efficiently and time deterministically. The parallel computational capability offered by this multicore hardware can only be exploited and utilized if the ECU application software is parallelized. Having provided with such parallelized software, the real time operating system scheduler component should schedule the time critical tasks so that, all the computational cores are utilized to a greater extent and the safety critical deadlines are met. As original equipment manufacturers (OEMs) are always motivated towards adding more sophisticated features to the existing ECUs, a large number of task sets can be effectively scheduled for execution within the bounded time limits. In this paper, a hybrid scheduling algorithm has been proposed, that meticulously calculates the running slack of every task and estimates the probability of meeting deadline either being in the same partitioned queue or by migrating to another. This algorithm was run and tested using a scheduling simulator with different real time task models of periodic tasks. This algorithm was also compared with the existing static priority scheduler, which is suggested by Automotive Open Systems Architecture (AUTOSAR). The performance parameters considered here are, the % of core utilization, average response time and task deadline missing rate. It has been verified that, this proposed algorithm has considerable improvements over the existing partitioned static priority scheduler based on each performance parameter mentioned above.

Matching data distribution to workload distribution is important to improve the performance of distributedmemory multiprocessors. While data and workload distribution can be tailored to fit a particular problem to a particular distributed-memory architecture, it is often difficult to do so for various reasons including complexity of address computation, runtime data movement, and irregular resource usage. This report presents our study on multithreading for distributed-memory multiprocessors. Specifically, we investigate the effects of multithreading on data distribution and workload distribution with variable thread granularity. Various types of workload distribution strategies are defined along with thread granularity. Several types of data distribution strategies are investigated. These include row-wise cyclic, k-way partial-row cyclic, and blocked distribution. To investigate the performance of multithreading, two problems are selected: highly sequential Gaussian Elimination with Partial Pivoting and highly parallel Matrix Multiplication. Execution results on the 80-processor EM-4 distributed-memory multiprocessor indicate that multithreading can offset the loss that is due to the mismatch between data distribution and workload distribution even for sequential and irregular problems while giving high absolute performance.

Network diagnosis, an essential research topic for traditional networking systems, has not received much attention for wireless sensor networks. Existing sensor debugging tools like sympathy or EmStar rely heavily on an add-in protocol that generates and reports a large amount of status information from individual sensor nodes, introducing network overhead to a resource constrained and usually traffic sensitive sensor network. We report in this study our initial attempt at providing a light-weight network diagnosis mechanism for sensor networks. We propose PAD, a probabilistic diagnosis approach for inferring the root causes of abnormal phenomena. PAD employs a packet marking algorithm for efficiently constructing and dynamically maintaining the inference model. Our approach does not incur additional traffic overhead for collecting desired information. Instead, we introduce a probabilistic inference model which encodes internal dependencies among different network elements, for online diagnosis of an operational sensor network system. Such a model is capable of additively reasoning root causes based on passively observed symptoms. We implement the PAD design in our sea monitoring sensor network test-bed and validate its effectiveness. We further evaluate the efficiency and scalability of this design through extensive trace-driven simulations.

To exploit a heterogeneous computing (HC) environment, an application task may be decomposed into subtasks that have data dependencies. Subtask matching and scheduling consists of assigning subtasks to machines, ordering subtask execution for each machine, and ordering intermachine data transfers. The goal is to achieve the minimal completion time for the task. A heuristic approach based on a genetic algorithm is developed to do matching and scheduling in HC environments. It is assumed that the matcher/scheduler is in control of a dedicated HC suite of machines. The characteristics of this genetic-algorithm-based approach include: separation of the matching and the scheduling representations, independence of the chromosome structure from the details of the communication subsystem, and consideration of overlap among all computations and communications that obey subtask precedence constraints. It is applicable to the static scheduling of production jobs and can be readily used to collectively schedule a set of tasks that are decomposed into subtasks. Some parameters and the selection scheme of the genetic algorithm were chosen experimentally to achieve the best performance. Extensive simulation tests were conducted. For small-sized problems (e.g., a small number of subtasks and a small number of machines), exhaustive searches were used to verify that this genetic-algorithm-based approach found the optimal solutions. Simulation results for larger-sized problems showed that this genetic-algorithm-based approach outperformed two nonevolutionary heuristics and a random search.

Emerging pervasive information and computational environments require a content-based middleware infrastructure that is scalable, self-managing, and asynchronous. In this paper, we propose associative rendezvous (AR) as a paradigm for content-based decoupled interactions for pervasive ...

A resource allocation framework is presented for spectrum underlay in cognitive radio networks. We consider both interference constraints for primary users and quality of service (QoS) constraints for secondary users. Specifically, interference from secondary users to primary users is constrained to be below a tolerable limit. Also, signal to interference plus noise ratio (SINR) of each secondary user is maintained higher than a desired level for QoS insurance. We propose admission control algorithms to be used during high network load conditions which are performed jointly with power control so that QoS requirements of all admitted secondary users are satisfied while keeping the interference to primary users below the tolerable limit. If all secondary users can be supported at minimum rates, we allow them to increase their transmission rates and share the spectrum in a fair manner. We formulate the joint power/rate allocation with proportional and max-min fairness criteria as optimization problems. We show how to transform these optimization problems into a convex form so that their globally optimal solutions can be obtained. Numerical results show that the proposed admission control algorithms achieve performance very close to that of the optimal solution. Also, impacts of different system and QoS parameters on the network performance are investigated for the admission control, and rate/power allocation algorithms under different fairness criteria.

This paper provides a complete framework for thread migration using JPDA. In our framework neither we lose portability nor do we insert any artificial code. The system developed based on our framework needs no extra involvement of programming to continue the whole migration system. It is a powerful autonomous system for heterogeneous environment maintaining its portability since Java Virtual Machine (JVM) is not modified.

The frenetic development of the current architectures places a strain on the current state-of-the-art programming environments. Harnessing the full potential of such architectures has been a tremendous task for the whole scientific computing community.

E-collaboration and collaborative systems bring geographically dispersed teams together, supporting communication, coordination and cooperation. The paper presents a review of research in the area of creating collaborative application taxonomies. We analyze previous literature, and examine commercial products and research prototypes in the domain of collaborative computing. Our survey provides a list of basic collaboration services, and the tools are presented with regards to the services they provide. All surveyed tools are then classified to four categories of functional services. In conclusion, the paper highlights a number of areas for consideration and improvement that arise when studying collaborative applications.

We propose a steganalytic algorithm for triangle meshes, based on the supervised training of a classifier by discriminative feature vectors. After a normalization step, the triangle mesh is calibrated by one step of Laplacian smoothing and then a feature vector is computed, encoding geometric information corresponding to vertices, edges and faces. For a given steganographic or watermarking algorithm, we create a training set containing unmarked meshes and meshes marked by that algorithm, and train a classifier using Quadratic Discriminant Analysis. The performance of the proposed method was evaluated on six well-known watermarking/steganographic schemes with satisfactory accuracy rates.

The popularity of business process re-engineering (BPR) and its international diffusion from the United States make it important to understand the influence of cultural factors on this concept. The global economic prominence of the Chinese and their distinctive cultural characteristics prompted our study of Chinese business process re-engineering. This article addresses a large gap in the Chinese management literature and is intended to help those who are managing organizations or marketing information technology (IT) products and related services in Greater China. We systematically compare IT-enabled change in the American and Chinese business cultures. Informal planning and process modelling, highly interdependent social and organizational relationships with ingrained hierarchies, and the prevailing attitudes towards information management and organizational change will shape the preparation for IT-enabled process innovation efforts as well as the design and implementation of IT-enhanced business process models in Chinese organizations.

The growing design complexity of today's embedded real-time systems requires new techniques aiming the raising of the abstraction level since earlier stages of design in order to deal with such complexity in a suitable way. This paper reports a case study, which provides an assessment of two well-know highlevel paradigms, namely Aspect-(AO) and Object-Oriented (OO) paradigms. Concepts of both paradigms were applied at modeling phase of a Distributed Embedded Real-Time System (DERTS). The handling of DERTS' functional and non-functional requirements (at modeling level) using AO and OO concepts is discussed. Both paradigms are compared using of a set of software engineering metrics, which were adapted to be applied at modeling level. The presented results show the suitability of each paradigm for DERTS specification in terms of reusability quality of model elements.

This paper presents a framework that enables the development of Java applications that execute on CPUs, graphics processing units (GPUs) and clusters of CPUs/GPUs. Applications are specified in an OpenMPlike fashion, accessing data through a framework-provided data API. The framework enables the efficient execution of applications in CPU and/or GPU by relying on two key features: (i) parallelism exploitation patterns are specified by additional aspect modules; and (ii) data layout can be selected according to the target platform. This paper describes how the framework abstractions are mapped and how the framework intrinsically supports the development of applications with hybrid parallelism by composing aspect modules with a given base program. Performance results show that the framework provides a performance level similar to traditional approaches and enables better performance portability for a given base program.

Even though listening comprehension is an important language skill in second language learning, it is considered to be the most difficult skill to learn. Besides, the teaching of listening comprehension among primary pupils is often neglected even though the role of listening comprehension in language teaching has been repeatedly emphasized. Using an action research design, this study explores the teaching of listening comprehension utilizing YouTube and Video-Podcast involving 40 Primary Year 4 pupils from one of the cluster schools of excellence in the northern region of Malaysia. This study attempts to investigate to what extent did the use of YouTube and Video-Podcast enhance Primary Year 4 pupils’ listening comprehension. This study adopted multiple data collection methods including pre-post tests, reflection, observation, and focused group interviews. However, the data analysis section was mostly pre and post tests data and observation. Only these data collection and analysis ...

In a (t, n)-threshold multi-secret sharing scheme, several secrets are shared among n participants in such a way that any t (or more) of them can reconstruct the secrets while a group of (t -1) can not obtain any information. Therefore, when such schemes are used to distribute sensitive information over a network, fault tolerance property is achieved since even if nt of the nodes go out of function, the remaining t nodes suffice to recover the information. In 2009, Wang et al. proposed a verifiable (t, n)-threshold multi-secret sharing scheme (WTS) based on elliptic curves in which the secrets can change periodically [Wireless Pers. Commun., Springer-Verlage,

In this paper we discuss the development of a valuation system of asset-liability management of portfolios of life insurance policies on advanced architectures. According to the new rules of the Solvency II project, numerical simulations must provide reliable estimates of the relevant quantities involved in the contracts; therefore, valuation processes have to rely on accurate algorithms able to provide solutions in a suitable turnaround time. Our target is to develop an effective valuation software. At this aim we first introduce a change of numéraire in the stochastic processes for risks sources, thus providing estimates under the forward risk-neutral measure that result in a gain in accuracy. We then parallelize the Monte Carlo method to speed-up the simulation process.

The concept of energy-efficient networking has begun to spread in the past few years, gaining increasing popularity. Besides the widespread sensitivity to ecological issues, such interest also stems from economic needs, since both energy costs and electrical requirements of telcos' and Internet Service Providers' infrastructures around the world show a continuously growing trend. In this respect, a common opinion among networking researchers is that the sole introduction of low consumption silicon technologies may not be enough to effectively curb energy requirements. Thus, for disruptively boosting the network energy efficiency, these hardware enhancements must be integrated with ad-hoc mechanisms that explicitly manage energy saving, by exploiting network-specific features. This paper aims at providing a twofold contribution to green networking. At first, we explore current perspectives in power consumption for next generation networks. Secondly, we provide a detailed survey on emerging technologies, projects, and work-in-progress standards, which can be adopted in networks and related infrastructures in order to reduce their carbon footprint. The considered approaches range from energy saving techniques for networked hosts, to technologies and mechanisms for designing nextgeneration and energy-aware networks and networking equipment.

Dynamic Adaptive Streaming over HTTP (DASH) is a recently proposed standard that offers different versions of the same media content to adapt the delivery process over the Internet to dynamic bandwidth fluctuations and different user device capabilities. The peer-to-peer (P2P) paradigm for video streaming allows us to leverage the cooperation among peers, guaranteeing the service of video requests with increased scalability and reduced cost. We propose to combine these two approaches in a P2P-DASH architecture, exploiting the potentiality of both. The new platform is made of several swarms and a different DASH representation is streamed within each of them; unlike client-server DASH architectures, where each client autonomously selects which version to download according to current network conditions and to its device resources, we put forth a new rate control strategy implemented at peer site to maintain a good viewing quality to the local user and to simultaneously guarantee the s...

The next industrial revolution is said to be paved by the use of novel Internet of Things (IoT) technology. One important aspect of the modern IoT infrastructures is decentralised communication, often called Peer-to-Peer (P2P). In the context of industrial communication, P2P contributes to resilience and improved stability for industrial components. Current industrial facilities, however, still rely on centralised networking schemes which are considered to be mandatory to comply with security standards. In order to succeed, introduced industrial P2P technology must maintain the current level of protection and also consider possible new threats. The presented work starts with a short analysis of wellestablished industrial communication infrastructures and how these could benefit from decentralised structures. Subsequently, previously undefined Information Technology (IT) security requirements are derived from the new cloud based decentralised industrial automation model architecture presented in this paper. To meet those requirements, state-of-the-art communication schemes and their open source implementations are presented and assessed for their usability in the context of industrial IoT. Finally, derived building blocks for industrial IoT P2P security are presented which are qualified to comply with the stated industrial IoT security requirements.