Systematic Refinement of Performance Models for Concurrent Component-based Systems

Software performance engineering provides techniques to analyze and predict the performance (e.g., response time or resource utilization) of software systems to avoid implementations with insufficient performance. These techniques operate on models of software, often at an architectural level, to enable early, design-time predictions for evaluating design alternatives. Current software performance engineering approaches allow the prediction of performance at design time, but often provide cryptic results (e.g., lengths of queues). These prediction results can be hardly mapped back to the software architecture by humans, making it hard to derive the right design decisions. In this paper, we integrate software cartography (a map technique) with software performance engineering to overcome the limited interpretability of raw performance prediction results. Our approach is based on model transformations and a general software visualization approach. It provides an intuitive mapping of prediction results to the software architecture which simplifies design decisions. We successfully evaluated our approach in a quasi experiment involving 41 participants by comparing the correctness of performance-improving design decisions and participants’ time effort using our novel approach to an existing software performance visualization.

Predicted effects of anthropogenic climate change on estuarine and coastal organisms are complex, and early life history stages of calcified ectotherms are amongst the most sensitive groups. Despite the importance of understanding their vulnerability, we lack information on the effects of multiple stressors on the embryonic development of estuarine and burrowing organisms, mainly mangrove-associated species. Here, we determined the combined effects of elevated temperature and decreased pH on the embryonic development of the estuarine fiddler crab Leptuca thayeri. Initially, the microhabitat (burrow) of ovigerous (egg-bearing) females was measured for temperature, pH, and salinity, which provided control values in our laboratory experiment. Embryos at the early stage of development were subjected to cross-factored treatments of predicted temperature and pH and evaluated for development rate, survivorship, and volume until their later embryonic stage. Embryo development was faster at early and later stages of development, and survivorship was lower under elevated temperature. Embryos under reduced pH showed advanced embryonic stages at their late development stage. Higher egg volume was observed in a warmer and acidified environment, and lower volume in warmer and non-acidified conditions, indicating that embryo development is synergistically affected by warming and acidification. More than 70% of embryos developed until late stages under the multiple-stressors treatment, giving insights on the effects of a warm and acidified environment on burrowing estuarine organisms and their early stages of development.

Real-time process algebra (RTPA) is a denotational mathematical structure for denoting and manipulating system behavioral processes. RTPA is designed as a coherent algebraic system for intelligent and software system modeling, specification, refinement, and implementation. RTPA encompasses 17 metaprocesses and 17 relational process operations. RTPA can be used to describe both logical and physical models of software and intelligent systems. Logic views of system architectures and their physical platforms can be described using the same set of notations. When a system architecture is formally modeled, the static and dynamic behaviors performed on the architectural model can be specified by a three-level refinement scheme at the system, class, and object levels in a top-down approach. RTPA has been successfully applied in real-world system modeling and code generation for software systems, human cognitive processes, and intelligent systems.

Database system performance evaluation models: A survey

One of the big challenges faced by content-based image retrieval (CBIR) is the 'semantic gap' between the visual features and the richness of human semantics for image content. We put forward a neural network approach to extract the image fuzzy semantics ground on linguistic expression based image description framework (LEBID). We utilize the linguistic variable to depict the texture semantics according to Tamura texture model, so we can describe the image in linguistic expression such as coarse, very line-like. Moreover, we use feedforward neural network (NN) to model the vagueness of human visual perception and to extract the fuzzy semantic feature. Our experiments demonstrate that NN outperforms other method such as genetic algorithm on the complexity of model, and it also achieves good retrieval performance.

The execution context of today's software systems changes continually, which makes systems have to cope with changing environments while at the same time facing high non-functional requirements such as flexibility and dependability. Runtime adaptation technology can modify behaviors and structures in response to changes in the system itself or in its environment and thus improve dependability at run time. This leads to a more flexible and effective way to build dependable software system. However, current works address adaptation often remain a neglected gap between the architecture model and the system state. To solve this problem, we present a systematic process that covers requirements modeling, architecture and system modeling of trustworthy software based on a runtime self-adaptation perspective.

Changes in nucleolar size and nucleolar vacuolation at early stages of fiber development and final fiber dimensions were determined for cotton of different species: Gossypium hirsutum L. cv. B49, Gossypium barbadense L. cv. Menoufi and Gossypium arboreum L. cv. Virnar. Size of the nucleolus in combination with its vacuolation at an early stage of development was found to be clearly associated with the final result of fiber development.

Purpose– The purpose of this study is to explore the early stage of development of a cluster. The literature on early stage of cluster development shows that there are often random effects such as an entrepreneur and spin-off companies, and in this study, a coordinated approach for cluster development is described.Design/methodology/approach– A single exploratory case study approach is followed. The aerospace cluster in the Spokane region, State of Washington, is described. Data from a variety of sources are triangulated to enhance the credibility of the case study findings.Findings– It was found that although there are many types of collaborations occurring in the region, which involve policy and government organizations, the main driver of the early-stage cluster development is manufacturers-led coordinating mechanism. Individual manufacturers are too small to be successful in the aerospace industry, and they are collaborating to present a united “front” to out-of-the-region customers. Once customers place an order, then within this coordinating mechanism, the work is divided among different manufacturers.Research limitations/implications– The research has two main limitations. First, it is a single case study, and therefore, the results may not be generalizable. Second, the cluster is in an early stage of development, so it is not (yet) clear whether this manufacturers-led coordinated approach will have long-term success.Practical implications– The studies offer potential for cluster development that go beyond relying on a single entrepreneur or on mostly government- or policy-driven initiatives. Instead, this is an approach that can be used by industry to lift the overall competitiveness of their region.Social implications– This cluster development approach offers potential for economic development of smaller regions which mainly consist of small- and medium-sized companies without endowment benefits or a large local customer base.Originality/value– This study adds to the existing knowledge on clusters and cluster types. The identified cluster approach does not fit with the main types of clusters that have been identified in the literature. The companies involved are mainly small- to medium-sized companies, but by coordinating their capabilities, they are able to present core capabilities in a much more attractive manner to customers. This cluster development approach is not driven by or achieved through advantages in innovation, vertical or horizontal supply chain competition and advantages, creation of spin-off firms, or a regional demand base as customers are located outside the region. It deviates in terms of the types of companies involved and, mostly, in a sense that it acts as one unit to customers who are located outside the region.

Macroscopic Spectral Imaging and Gene Expression Analysis of the Early Stages of Melanoma

This paper presents a review of approaches that may be useful for the selection of solvents in the early stages of process development for the synthesis of active pharmaceutical ingredients. Characteristics of the methodologies and their applicability in early stages are explored. Early stages of development are recognised as ideal for detecting benefits and issues regarding the use of solvents. The “system” concept is introduced for the evaluation and selection of solvents in pharmaceutical processes; this concept does not yet seem to be widely utilised within the fine chemicals and pharmaceutical industries. System analysis is considered an important tool for viewing solvent selection from a holistic perspective. Hence, approaches suitable for the early stages of development and considering a holistic perspective might deliver more sustainable processes. The evolution of the synthesis of Ibuprofen API is used to illustrate this concept.

Nowadays, the functional requirements of embedded systems increase rapidly. CNC systems are also influenced by this trend. In order to solve the growing complexity of CNC systems, open CNC system is considered as a key technology to take on these challenges. Reconfigurable CNC system is an open CNC which allows modifying system software in response to changing market demands or technologies. This paper presents a component model and layered system architecture for reconfigurable CNC systems, which addresses the functional and non-functional requirements of CNC. The proposed model improves the reusability of system software and facilitates software updating. The layered architecture also helps to reduce the run-time overhead, achieve the property of loose coupling and facilitate the implementation of some advanced functions. In order to verify our design, some experiments are carried out.

Both heat shock proteins (HSPs), which have key roles in vital cell functions, as well as members of the mitogen-activated protein kinases (MAPKs), which adjust gene expression by transducing cellular signals to the nucleus, are necessary for normal embryonic development in vertebrates. Therefore, protein expression levels of HSP70 and HSP90 and the activation of members of the MAPK protein family, such as p38 MAPK, ERKs, and JNKs were studied in the early developmental stages of the Gilthead sea bream, Sparus aurata Linnaeus, 1758. The protein expression of HSP70 and the phosphorylation ratio of JNKs remained at equal levels at all examined developmental stages, while the other examined proteins exhibited a differential profile. HSP90 levels were mostly increased at the 16-cell stage and towards the morula stages, and the lowest values were observed at the two- to four-cell and one-half epiboly stages. While p38 MAPK phosphorylation ratio exhibited increased values mostly in the early developmental stages, the opposite was observed concerning ERK phosphorylation ratio, where increased values were observed in the later embryonic stages (high blastula to one-half epiboly stages). These differential profiles of the examined protein expression levels highlight the importance of these proteins during embryogenesis and pave the way for further research to unveil their distinct role in early development.

Many of today‟s advanced simulation tools are suitable for modeling specific systems; however, they provide rather limited support for model building and management. Setting up a detailed vehicle simulation model requires more than writing down state equations and running them on a computer. In this paper, we describe how modern software techniques can be used to support modeling and design activities, with the objective of providing better system models more quickly by assembling these system models in a “plug-and-play” architecture. Instead of developing detailed models specifically for Argonne National Laboratory‟s Autonomie modeling tool, we have chosen to place emphasis on integrating and re-using the system models, regardless of the environment in which they were initially developed. By way of example, this paper describes a vehicle model composed of a detailed engine model from GT Power, a transmission from AMESim, and with vehicle dynamics from CarSim. The paper will explain the different options available for the interface and how each of these options can be implemented. It will use a simple case study to show how the detailed expert simulation models can be used with simpler Simulink models to address different vehicle design issues. INTRODUCTION One of the basic capabilities that an enterprise-wide modeling and simulation tool needs is to provide a framework for integrating models developed in different languages/tools. Because different expert tools have distinct advantages for modeling specific phenomena, numerous tools are used across companies, such as automotive original equipment manufacturers (OEMs). When these models are available, nevertheless the attempt to integrate them into a single environment to build an accurate system model is very onerous. As a result, most vehicle models used for analysis are usually based on steady-state look-up tables. The lack of a common framework to link such expert models results in isolated pockets of model-rich design groups. The open architecture of Autonomie [1, 2], a modeling tool developed by Argonne National Laboratory (Argonne) over the past four years in collaboration with General Motors (GM), supports the rapid integration and analysis of powertrain/propulsion systems and technologies for rapid technology sorting and evaluation of fuel economy improvement under dynamic/transient testing conditions. The tool, developed in the MathWorks environment, is based on a forward-looking model architecture. Its plug-and-play architecture provides a common framework in which expert tools can be linked to build detailed vehicle models. In this paper, we will explain how Autonomie is used to act as the interface between models developed with expert tool by taking the GT-Power engine model, AMESim transmission model, and CarSim vehicle dynamics models as examples. THE NEED FOR DETAILED SYSTEM MODELS Each type of model has its own advantages and disadvantages. While Simulink models based on simple look-up tables are easy to develop and use, they lack the ability to simulate the details of the plant‟s physical interactions. As a result, simple plant models cannot support control systems development. More detailed models are also needed to evaluate the effect of new technology. Different expert tools are available to meet such needs. It is far more practical to use those tools than to build and validate an equally detailed model in Simulink. While the detailed models add accuracy, the input data needed for those models are difficult to obtain, and the models run slower. Hence, engineers must switch between the detailed and simpler models depending on the analysis and what level of accuracy in the simulation results is desired. As shown in Fig. 1, Autonomie provides a convenient way to use models of appropriate fidelity by enabling a plug-and-play function with the models and by interfacing with expert system tools.

This paper describes a multiview characterization of concurrent software and systems suitable for displaying and analyzing performance information. The views draw from well-known descriptions, and are compatible with established techniques and tools such as execution graphs, Petri Nets, State-Charts, structured design or object-oriented design, and various models for performance. The views are connected by means of a "Core model" and are used together to extract information relating to system integration, such as interprocess overheads, and the delay behavior of separate software components in complex systems. The integration of the views in the Core assists by converting results in one view (such as scheduling delay for resources) to parameters in another (such as delays along a path). The ultimate goal of the views is to support designers in making tradeoffs which involve performance, and to provide early assessment of the performance potential of software designs.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Toxic effects of magnesium oxide nanoparticles on early developmental and larval stages of zebrafish (Danio rerio)