This paper describes an architecture-based dynamic adaptation model and framework for adaptive software systems. The framework provides for a reusable adaptation infrastructure and uses a layered architecture pattern....
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This paper describes an architecture-based dynamic adaptation model and framework for adaptive software systems. The framework provides for a reusable adaptation infrastructure and uses a layered architecture pattern. It also provides separation of concerns from the system's software architecture and supports internal state information checkpointing and restoration. Any dynamic software adaptation process, whether instigated internally or externally, makes runtime changes only to affected components. The dynamic adaptation model separates adaptation-impacted parts of a system from those that need not be concerned with the dynamic adaptation.
Low coupling is a service-oriented design and development principle that should be taken into account during all stages. Having loosely coupled services not only increases service reusability, but also prevents the pr...
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Low coupling is a service-oriented design and development principle that should be taken into account during all stages. Having loosely coupled services not only increases service reusability, but also prevents the propagation of changes to other services and thus simplifies maintenance of service-oriented systems as well. In this paper, we focus on measuring conceptual coupling as an indicator of how much a service depends on the other services from functional point of view. Latent Semantic Indexing (LSI) is a well-known technique in the field of information retrieval (IR) which has been widely used to measure the degree of semantic relationship between text based documents. In this paper, a metric namely CCS is proposed to measure the degree of conceptual coupling of a service to its environment based on the LSI technique. The proposed metric is evaluated theoretically based on a set of coupling principles.
The memory scheme is one of the most widely employed techniques in Evolutionary Algorithms for solving dynamic optimization problems. The updating strategy is a key concern for the memory scheme. Unfortunately, the ex...
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Wireless sensor networks generate volumes of scientific observations. However, gathered data is typically not published for use by other scientists. This paper analyses the reasons that so little sensor network data i...
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Spike sorting is the essential step in analyzing recording spike signals for studying information processing mechanisms within the nervous system. Overlapping is one of the most serious problems in the spike sorting f...
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Mobile Ad hoc Networks (MANETs) are networks dynamically formed by mobile nodes without the support of prior stationary infrastructures. The essential features of such a network are local broadcast, mobility and proba...
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Mobile Ad hoc Networks (MANETs) are networks dynamically formed by mobile nodes without the support of prior stationary infrastructures. The essential features of such a network are local broadcast, mobility and probability. In our earlier work, we proposed the pw-calculus to formally model and reason about MANTEs from a group probabilistic perspective, in which a MANET node can locally broadcast messages to a group of nodes within its physical transmission range with a certain probability. The group probabilities depend on the network topology which can evolve with the mobility of nodes. In this paper, to capture the behavior equivalence of networks, the structural congruence is investigated and the operational semantics is refined. Moreover, we define the notion of open bisimulation and prove it to be a congruence relation. Based on this, we discuss several nontrivial properties of MANETs such as mobile node equivalence and replacement. Finally, we by a case study illustrate our calculus and use it to analyze the probability of a transmission via routines.
Design patterns are widely used in design of software product in practice. To understand and discover the design patterns used in source code, we develop a run-time approach to explore the patterns from Java source co...
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ISBN:
(纸本)9781457705359
Design patterns are widely used in design of software product in practice. To understand and discover the design patterns used in source code, we develop a run-time approach to explore the patterns from Java source code. To capture the inherent relations among patterns, we present a relational calculus to specify the patterns in a precise way. This calculus can capture the relations such as inheritance, creation, reference etc. among objects and classes. On the other hand, we use a dynamic way to construct the object diagram from source code. Thus, we transform the pattern discovery problem into the SAT one on the model we construct. With constraint solver (like SAT solver), we can decide whether the patterns regulated by the relational calculus exist in the given Java source code. The corresponding tool has been implemented and the preliminary experiments show that our approach is effective.
The Infrastructure-as-a-Service (IaaS) cloud computing model has become a compelling computing solution with a proven ability to reduce costs and improve resource efficiency. Virtualization has a key role in supportin...
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The Infrastructure-as-a-Service (IaaS) cloud computing model has become a compelling computing solution with a proven ability to reduce costs and improve resource efficiency. Virtualization has a key role in supporting the IaaS model. However, virtualization also makes it a target for potent rootkits because of the loss of control problem over the hosted Virtual Machines (VMs). This makes traditional in-guest security solutions, relying on operating system kernel trustworthiness, no longer an effective solution to secure the virtual infrastructure of the IaaS model. In this paper, we explore briefly the security problem of the IaaS cloud computing model, and present CloudSec, a new virtualization-aware monitoring appliance that provides active, transparent and real-time security monitoring for hosted VMs in the IaaS model. CloudSec utilizes virtual machine introspection techniques to provide fine-grained inspection of VM's physical memory without installing any monitoring code inside the VM. It actively reconstructs and monitors the dynamically changing kernel data structures instances, as a prior step to enable providing protection for kernel data structures. We have implemented a proof-of-concept prototype using VMsafe libraries on a VMware ESX platform. We have evaluated the system monitoring accuracy and the performance overhead of CloudSec.
Wireless sensor networking, as a burgeoning technology, supports the monitoring of physical environments and control of sensor data, and has been widely applied in many fields. Due to its unique features, a number of ...
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Wireless sensor networking, as a burgeoning technology, supports the monitoring of physical environments and control of sensor data, and has been widely applied in many fields. Due to its unique features, a number of formal theories, as well as verification tools, have been developed to make an in-depth study. In this paper, we propose a timed broadcasting language, the Timed Wireless Sensor Processes, with its operational semantics borrowing ideas from both the Timed CSP and the CBS. Moreover, we abstract a model of contention-based wireless sensor networking systems and formalize it using our language. We also simulate real-world scenarios in terms of labeled transition systems to demonstrate our methods in describing the dynamic behaviors of wireless systems.
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