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The global availability of communication services makes it possible to interconnect independently developed systems, called constituent systems, to provide new synergistic services and more efficient economic processes. The characteristics of these new Systems-of-Systems are qualitatively different from the classic monolithic systems. In the first part of this presentation we elaborate on these differences, particularly with respect to the autonomy of the constituent systems, to dependability, continuous evolution, and emergence. In the second part we look at a SoS from the point of view of cognitive complexity. Cognitive complexity is seen as a relation between a model of an SoS and the observer. In order to understand the behavior of a large SoS we have to generate models of adequate simplicity, i.e, of a cognitive complexity that can be handled by the limited capabilities of the human mind. We will discuss the importance of properly specifying and placing the relied-upon message interfaces between the constituent systems that form an open SoS and discuss simplification strategies that help to reduce the cognitive complexity. | System-of-Systems Complexity | 5,800 |
Over the last decade we have witnessed an increasing use of data processing in embedded systems. Where in the past the data processing was limited (if present at all) to the handling of a small number of "on-off control signals", more recently much more complex sensory data is being captured, processed and used to improve system performance and dependability. The advent of systems-of-systems aggravates the use of more and more data, for instance, by bringing together data from several independent sources, allowing, in principle, for even better performing systems. However, this ever stronger data-orientation brings along several challenges in system design, both technically and organisationally, and also forces manufacturers to think beyond their traditional field of expertise. In this short paper, I will address these new design challenges, through a number of examples. The paper finishes with concrete challenges for supporting tools and techniques for system design in this new context. | Challenges for modelling and analysis in embedded systems and
systems-of-systems design | 5,801 |
This paper presents some of the results of the first year of DANSE, one of the first EU IP projects dedicated to SoS. Concretely, we offer a tool chain that allows to specify SoS and SoS requirements at high level, and analyse them using powerful toolsets coming from the formal verification area. At the high level, we use UPDM, the system model provided by the british army as well as a new type of contract based on behavioral patterns. At low level, we rely on a powerful simulation toolset combined with recent advances from the area of statistical model checking. The approach has been applied to a case study developed at EADS Innovation Works. | Contracts and Behavioral Patterns for SoS: The EU IP DANSE approach | 5,802 |
Exhaustive formal verification for systems of systems (SoS) is impractical and cannot be applied on a large scale. In this paper we propose to use statistical model checking for efficient verification of SoS. We address three relevant aspects for systems of systems: 1) the model of the SoS, which includes stochastic aspects; 2) the formalization of the SoS requirements in the form of contracts; 3) the tool-chain to support statistical model checking for SoS. We adapt the SMC technique for application to heterogeneous SoS. We extend the UPDM/SysML specification language to express the SoS requirements that the implemented strategies over the SoS must satisfy. The requirements are specified with a new contract language specifically designed for SoS, targeting a high-level English- pattern language, but relying on an accurate semantics given by the standard temporal logics. The contracts are verified against the UPDM/SysML specification using the Statistical Model Checker (SMC) PLASMA combined with the simulation engine DESYRE, which integrates heterogeneous behavioral models through the functional mock-up interface (FMI) standard. The tool-chain allows computing an estimation of the satisfiability of the contracts by the SoS. The results help the system architect to trade-off different solutions to guide the evolution of the SoS. | SoS contract verification using statistical model checking | 5,803 |
Inspections and testing are two of the most commonly performed software quality assurance processes today. Typically, these processes are applied in isolation, which, however, fails to exploit the benefits of systematically combining and integrating them. In consequence, tests are not focused based on early defect detection data. Expected benefits of such process integration include higher defect detection rates or reduced quality assurance effort. Moreover, when conducting testing without any prior information regarding the system's quality, it is often unclear how to focus testing. A systematic integration of inspection and testing processes requires context-specific knowledge about the relationships between inspections and testing. This knowledge is typically not available and needs to be empirically identified and validated. Often, context-specific assumptions can be seen as a starting point for generating such knowledge. Based on the In2Test approach, which uses inspection data to focus testing, we present in this article how knowledge about the relationship between inspections and testing can be gained, documented, and evolved in an analytical or empirical manner. In addition, this article gives an overview of related work and highlights future research directions. | Integrating Inspection and Test Processes Based on Context-Specific
Assumptions | 5,804 |
Regression testing is performed to provide confidence that changes in a part of software do not affect other parts of the software. An execution of all existing test cases is the best way to re-establish this confidence. However, regression testing is an expensive process---there might be insufficient resources (e.g., time, workforce) to allow for the re-execution of all test cases. Regression test prioritization techniques attempt to re-order a regression test suite based on some criteria so that highest priority test cases are executed earlier. In this study, we want to prioritize test cases for regression testing based on the dependency network of faults. In software testing, it is common that some faults are consequences of other faults (leading faults). Moreover, dependent faults can be removed if and only if the leading faults have been removed. Our goal is to prioritize test cases so that test cases that exposed leading faults (the most central faults in the fault dependency network) in the system testing phase, are executed first in regression testing. We present ComReg, a test case prioritization technique based on the dependency network of faults. We model a fault dependency network as a directed graph and identify leading faults to prioritize test cases for regression testing. We use a centrality aggregation technique which considers six network representative centrality metrics to identify leading faults in the fault dependency network. We also discuss the use of fault communities to select an arbitrary percentage of the test cases from a prioritized regression test suite. We conduct a case study that evaluates the effectiveness and applicability of the proposed method. | ComReg: A Complex Network Approach to Prioritize Test Cases for
Regression Testing | 5,805 |
Programmers using software components have to follow protocols that specify when it is legal to call particular methods with particular arguments. For example, one cannot use an iterator over a set once the set has been changed directly or through another iterator. We formalize the notion of dynamic package interfaces (DPI), which generalize state-machine interfaces for single objects, and give an algorithm to statically compute a sound abstraction of a DPI. States of a DPI represent (unbounded) sets of heap configurations and edges represent the effects of method calls on the heap. We introduce a novel heap abstract domain based on depth-bounded systems to deal with potentially unboundedly many objects and the references among them. We have implemented our algorithm and show that it is effective in computing representations of common patterns of package usage, such as relationships between viewer and label, container and iterator, and JDBC statements and cursors. | A Notion of Dynamic Interface for Depth-Bounded Object-Oriented Packages | 5,806 |
A hallmark of object-oriented programming is the ability to perform computation through a set of interacting objects. A common manifestation of this style is the notion of a package, which groups a set of commonly used classes together. A challenge in using a package is to ensure that a client follows the implicit protocol of the package when calling its methods. Violations of the protocol can cause a runtime error or latent invariant violations. These protocols can extend across different, potentially unboundedly many, objects, and are specified informally in the documentation. As a result, ensuring that a client does not violate the protocol is hard. We introduce dynamic package interfaces (DPI), a formalism to explicitly capture the protocol of a package. The DPI of a package is a finite set of rules that together specify how any set of interacting objects of the package can evolve through method calls and under what conditions an error can happen. We have developed a dynamic tool that automatically computes an approximation of the DPI of a package, given a set of abstraction predicates. A key property of DPI is that the unbounded number of configurations of objects of a package are summarized finitely in an abstract domain. This uses the observation that many packages behave monotonically: the semantics of a method call over a configuration does not essentially change if more objects are added to the configuration. We have exploited monotonicity and have devised heuristics to obtain succinct yet general DPIs. We have used our tool to compute DPIs for several commonly used Java packages with complex protocols, such as JDBC, HashSet, and ArrayList. | Dynamic Package Interfaces - Extended Version | 5,807 |
Market-driven software intensive product development companies have been more and more experiencing the problem of feature expansion over time. Product managers face the challenge of identifying and locating the high value features in an application and weeding out the ones of low value from the next releases. Currently, there are few methods and tools that deal with feature identification and they address the problem only partially. Therefore, there is an urgent need of methods and tools that would enable systematic feature reduction to resolve issues resulting from feature creep. This paper presents an approach and an associated tool to automate feature identification for web applications. For empirical validation, a multiple case study was conducted using three well known web applications: Youtube, Google and BBC. The results indicate that there is a good potential for automating feature identification in web applications. | Automated Feature Identification in Web Applications | 5,808 |
The paper describes the need for and goals of tool-integration within software development processes. In particular we focus on agile software development but are not limited to. The integration of tools and data between the different domains of the process is essential for an efficient, effective and customized software development. We describe what the next steps in the pursuit of integration are and how major goals can be achieved. Beyond theoretical and architectural considerations we describe the prototypical implementation of an open platform approach. The paper introduces platform apps and a functionality store as general concepts to make apps and their functionalities available to the community. We describe the implementation of the approach and how it can be practically utilized. The description is based on one major use case and further steps are motivated by various other examples. | Dynamic Integration of ALM Tools for Agile Software Development | 5,809 |
The success of a number of projects has been shown to be significantly improved by the use of a formalism. However, there remains an open issue: to what extent can a development process based on a singular formal notation and method succeed. The majority of approaches demonstrate a low level of flexibility by attempting to use a single notation to express all of the different aspects encountered in software development. Often, these approaches leave a number of scalability issues open. We prefer a more eclectic approach. In our experience, the use of a formalism-based toolkit with adequate notations for each development phase is a viable solution. Following this principle, any specific notation is used only where and when it is really suitable and not necessarily over the entire software lifecycle. The approach explored in this article is perhaps slowly emerging in practice - we hope to accelerate its adoption. However, the major challenge is still finding the best way to instantiate it for each specific application scenario. In this work, we describe a development process and method for automotive applications which consists of five phases. The process recognizes the need for having adequate (and tailored) notations (Problem Frames, Requirements State Machine Language, and Event-B) for each development phase as well as direct traceability between the documents produced during each phase. This allows for a stepwise verification/validation of the system under development. The ideas for the formal development method have evolved over two significant case studies carried out in the DEPLOY project. | Towards a Formalism-Based Toolkit for Automotive Applications | 5,810 |
The increasing role of software for developing products and services requires that organizations align their software-related activities with high-level business goals. In practice, this alignment is very difficult and only little systematic support is available. GQM+Strategies is a method that aims at aligning organizational goals, strategies, and measurements at all levels of an organization in a seamless way. This article describes a case study of applying GQM+Strategies in a globally op- erating industrial R&D organization developing special-purpose device products for B2B customers. The study analyzes how GQM+Strategies has helped clarify and harmonize the goal set of the organization. Results of the study indicate improved alignment and integration of different goals. In addition, the method helped to make the initially informal goal-setting more transparent and consequently enabled revising it while new, more important goals were discovered and comprehended. Moreover, several elements affecting the achievement of goals as well as impediments were identified. | The Effects of GQM+Strategies on Organizational Alignment | 5,811 |
Most of today's products and services are software-based. Organizations that develop software want to maintain and improve their competitiveness by controlling software-related risks. To do this, they need to align their business goals with software development strategies and translate them into quantitative project management. There is also an increasing need to justify cost and resources for software and system development and other IT services by demonstrating their impact on an organisation's higher-level goals. For both, linking business goals and software-related efforts in an organization is necessary. However, this is a challenging task, and there is a lack of methods addressing this gap. The GQM+Strategies approach effectively links goals and strategies on all levels of an organization by means of goal-oriented measurement. The approach is based on rationales for deciding about options when operationalizing goals and for evaluating the success of strategies with respect to goals. | Linking Software Development and Business Strategy Through Measurement | 5,812 |
Background: Distributed Pair Programming can be performed via screensharing or via a distributed IDE. The latter offers the freedom of concurrent editing (which may be helpful or damaging) and has even more awareness deficits than screen sharing. Objective: Characterize how competent distributed pair programmers may handle this additional freedom and these additional awareness deficits and characterize the impacts on the pair programming process. Method: A revelatory case study, based on direct observation of a single, highly competent distributed pair of industrial software developers during a 3-day collaboration. We use recordings of these sessions and conceptualize the phenomena seen. Results: 1. Skilled pairs may bridge the awareness deficits without visible obstruction of the overall process. 2. Skilled pairs may use the additional editing freedom in a useful limited fashion, resulting in potentially better fluency of the process than local pair programming. Conclusion: When applied skillfully in an appropriate context, distributed-pair programming can (not will!) work at least as well as local pair programming. | Distributed-Pair Programming can work well and is not just Distributed
Pair-Programming | 5,813 |
Today's software quality assurance techniques are often applied in isolation. Consequently, synergies resulting from systematically integrating different quality assurance activities are often not exploited. Such combinations promise benefits, such as a reduction in quality assurance effort or higher defect detection rates. The integration of inspection and testing, for instance, can be used to guide testing activities. For example, testing activities can be focused on defect-prone parts based upon inspection results. Existing approaches for predicting defect-prone parts do not make systematic use of the results from inspections. This article gives an overview of an integrated inspection and testing approach, and presents a preliminary case study aiming at verifying a study design for evaluating the approach. First results from this preliminary case study indicate that synergies resulting from the integration of inspection and testing might exist, and show a trend that testing activities could be guided based on inspection results. | Inspection and Test Process Integration Based on Explicit Test
Prioritization Strategies | 5,814 |
Modular reasoning about class invariants is challenging in the presence of dependencies among collaborating objects that need to maintain global consistency. This paper presents semantic collaboration: a novel methodology to specify and reason about class invariants of sequential object-oriented programs, which models dependencies between collaborating objects by semantic means. Combined with a simple ownership mechanism and useful default schemes, semantic collaboration achieves the flexibility necessary to reason about complicated inter-object dependencies but requires limited annotation burden when applied to standard specification patterns. The methodology is implemented in AutoProof, our program verifier for the Eiffel programming language (but it is applicable to any language supporting some form of representation invariants). An evaluation on several challenge problems proposed in the literature demonstrates that it can handle a variety of idiomatic collaboration patterns, and is more widely applicable than the existing invariant methodologies. | Flexible Invariants Through Semantic Collaboration | 5,815 |
In the context of software testing, generating complex data inputs is frequently performed using a grammar-based specification. For combinatorial reasons, an exhaustive generation of the data -- of a given size -- is practically impossible, and most approaches are either based on random techniques or on coverage criteria. In this paper, we show how to combine these two techniques by biasing the random generation in order to optimise the probability of satisfying a coverage criterion. | Random Grammar-based Testing for Covering All Non-Terminals | 5,816 |
Non Functional Properties (NFPs) such as security, quality of service and business related properties enhance the service description and provide necessary information about the fitness of its behaviour. These properties have become crucial criteria for efficient selection and composition of Web services. However, they belong to different domains, are complex, change frequently and have to be semantically described. The W3C standard WSPolicy,recommended to describe these properties doesn t define standardized specifications that cover all NFPs domains. Moreover, it doesn t provide an easy manner to express them independently of domains, and doesn t support their semantic. This paper proposes a Model driven approach to describe and automatically generate enriched Web services including semantic NFPs. It explores both the use of the OMG Profile for Modelling and Analysis of Real-Time Embedded Systems (MARTE) and the W3C standards. Mapping rules, from NFPs profile to WS-Policy and SAWSDL files, transforms NFPs into policies associated with WSDL elements. | MARTE Profile-based MDA approach for semantic NFP-aware Web services | 5,817 |
This paper presents an empirical study on how self- organized software teams could attain high performance using agile and lean practices. In particular, the paper qualitatively examines characteristics of high performance and self- organization in one project team. The case under study is a customer-driven student project, carried out to develop an alpha-version prototype. The paper also studies how certain agile software practices aid in initialising self-organization in the team. The main results indicate that self-organization as supported by certain Agile and Lean practices helps teams in achieving higher performance. | Attaining High-performing Software Teams with Agile and Lean Practices:
An Empirical Case Study | 5,818 |
In Software Product Line Engineering (SPLE) families of systems are designed, rather than developing the individual systems independently. Combinatorial Interaction Testing has proven to be effective for testing in the context of SPLE, where a representative subset of products is chosen for testing in place of the complete family. Such a subset of products can be determined by computing a so called t-wise Covering Array (tCA), whose computation is NP-complete. Recently, reduction rules that exploit basic feature model analysis have been proposed that reduce the number of elements that need to be considered during the computation of tCAs for Software Product Lines (SPLs). We applied these rules to CASA, a simulated annealing algorithm for tCA generation for SPLs. We evaluated the adapted version of CASA using 133 publicly available feature models and could record on average a speedup of $61.8\%$ of median execution time, while at the same time preserving the coverage of the generated array. | Improving CASA Runtime Performance by Exploiting Basic Feature Model
Analysis | 5,819 |
This case for the Transformation Tool Contest 2013 is about evaluating the scope and usability of transformation languages and tools for a set of four tasks requiring very different capabilities. One task deals with typical model-to-model transformation problem, there's a model-to-text problem, there are two in-place transformation problems, and finally there's a task dealing with validation of models resulting from the transformations. The tasks build upon each other, but the transformation case project also provides all intermediate models, thus making it possible to skip tasks that are not suited for a particular tool, or for parallelizing the work among members of participating teams. | The TTC 2013 Flowgraphs Case | 5,820 |
This paper presents a solution for the Flow Graphs case of the Transformation Tool Contest 2013, using the Eclectic model transformation tool. The solution makes use of several languages of Eclectic, showing how it is possible to combine them to address a non-trivial transformation problem in a concise and modulary way. | Solving the Flowgraphs Case with Eclectic | 5,821 |
FunnyQT is a model querying and model transformation library for the functional Lisp-dialect Clojure providing a rich and efficient querying and transformation API. This paper describes the FunnyQT solution to the TTC 2013 Flowgraphs Transformation Case. It solves all four tasks, and it has won the best efficiency award for this case. | Solving the TTC 2013 Flowgraphs Case with FunnyQT | 5,822 |
FunnyQT is a model querying and model transformation library for the functional Lisp-dialect Clojure providing a rich and efficient querying and transformation API. This paper describes the FunnyQT solution to the TTC 2013 Class Diagram Restructuring Transformation Case. This solution and the GROOVE solution share the best overall solution award for this case. | Solving the Class Diagram Restructuring Transformation Case with FunnyQT | 5,823 |
FunnyQT is a model querying and model transformation library for the functional Lisp-dialect Clojure providing a rich and efficient querying and transformation API. This paper describes the FunnyQT solution to the TTC 2013 Petri-Nets to Statcharts Transformation Case. This solution has won the best overall solution award and the best efficiency award for this case. | Solving the Petri-Nets to Statecharts Transformation Case with FunnyQT | 5,824 |
Software process models need to be variant-rich, in the sense that they should be systematically customizable to specific project goals and project environments. It is currently very difficult to model Variant-Rich Process (VRP) because variability mechanisms are largely missing in modern process modeling languages. Variability mechanisms from other domains, such as programming languages, might be suitable for the representation of variability and could be adapted to the modeling of software processes. Mechanisms from Software Product Line Engineering (SPLE) and concepts from Aspect- Oriented Software Engineering (AOSE) show particular promise when modeling variability. This paper presents an approach that integrates variability concepts from SPLE and AOSE in the design of a VRP approach for the systematic support of tailoring in software processes. This approach has also been implemented in SPEM, resulting in the vSPEM notation. It has been used in a pilot application, which indicates that our approach based on AOSE can make process tailoring easier and more productive. | Applying AOSE Concepts to Model Crosscutting Variability in Variant-Rich
Processes | 5,825 |
Many business web-based applications do not offer applications programming interfaces (APIs) to enable other applications to access their data and functions in a programmatic manner. This makes their composition difficult (for instance to synchronize data between two applications). To address this challenge, this paper presents Abmash, an approach to facilitate the integration of such legacy web applications by automatically imitating human interactions with them. By automatically interacting with the graphical user interface (GUI) of web applications, the system supports all forms of integrations including bi-directional interactions and is able to interact with AJAX-based applications. Furthermore, the integration programs are easy to write since they deal with end-user, visual user-interface elements. The integration code is simple enough to be called a "mashup". | Abmash: Mashing Up Legacy Web Applications by Automated Imitation of
Human Actions | 5,826 |
Web Service Composition creates new composite Web Services from the collection of existing ones to be composed further and embodies the added values and potential usages of Web Services. Web Service Composition includes two aspects: Web Service orchestration denoting a workflow-like composition pattern and Web Service choreography which represents an aggregate composition pattern. There were only a few works which give orchestration and choreography a relationship. In this paper, we introduce an architecture of Web Service Composition runtime which establishes a natural relationship between orchestration and choreography through a deep analysis of the two ones. Then we use an actor-based approach to design a language called AB-WSCL to support such an architecture. To give AB-WSCL a firmly theoretic foundation, we establish the formal semantics of AB-WSCL based on concurrent rewriting theory for actors. Conclusions that well defined relationships exist among the components of AB-WSCL using a notation of Compositionality is drawn based on semantics analysis. Our works can be bases of a modeling language, simulation tools, verification tools of Web Service Composition at design time, and also a Web Service Composition runtime with correctness analysis support itself. | Formal Model of Web Service Composition: An Actor-Based Approach to
Unifying Orchestration and Choreography | 5,827 |
Product metrics, such as size or complexity, are often used to identify defect-prone parts or to focus quality assurance activities. In contrast, quality information that is available early, such as information provided by inspections, is usually not used. Currently, only little experience is documented in the literature on whether data from early defect detection activities can support the identification of defect-prone parts later in the development process. This article compares selected product and inspection metrics commonly used to predict defect-prone parts. Based on initial experience from two case studies performed in different environments, the suitability of different metrics for predicting defect-prone parts is illustrated. These studies revealed that inspection defect data seems to be a suitable predictor, and a combination of certain inspection and product metrics led to the best prioritizations in our contexts. | Guiding Testing Activities by Predicting Defect-prone Parts Using
Product and Inspection Metrics | 5,828 |
Integrating inspection processes with testing processes promises to deliver several benefits, including reduced effort for quality assurance or higher defect detection rates. Systematic integration of these processes requires knowledge regarding the relationships between these processes, especially regarding the relationship between inspection defects and test defects. Such knowledge is typically context-dependent and needs to be gained analytically or empirically. If such kind of knowledge is not available, assumptions need to be made for a specific context. This article describes the relevance of assumptions and context factors for integrating inspection and testing processes and provides mechanisms for deriving assumptions in a systematic manner. | The Relevance of Assumptions and Context Factors for the Integration of
Inspections and Testing | 5,829 |
Explicitly linking software-related activities to an organisation's higher-level goals has been shown to be critical for organizational success. GQM+Strategies provides mechanisms for explicitly linking goals and strategies, based on goal-oriented strategic measurement systems. Deploying such strategic measurement systems in an organization is highly challenging. Experience has shown that a clear deployment strategy is needed for achieving sustainable success. In particular, an adequate deployment process as well as corresponding tool support can facilitate the deployment. This paper introduces the systematical GQM+Strategies deployment process and gives an overview of GQM+Strategies modelling and associated tool support. Additionally, it provides an overview of industrial applications and describes success factors and benefits for the usage of GQM+Strategies. | A Deployment Process for Strategic Measurement Systems | 5,830 |
Measuring and evaluating software quality has become a fundamental task. Many models have been proposed to support stakeholders in dealing with software quality. However, in most cases, quality models do not fit perfectly for the target application context. Since approaches for efficiently adapting quality models are largely missing, many quality models in practice are built from scratch or reuse only high-level concepts of existing models. We present a tool-supported approach for the efficient adaptation of quality models. An initial empirical investigation indicates that the quality models obtained applying the proposed approach are considerably more consistently and appropriately adapted than those obtained following an ad-hoc approach. Further, we could observe that model adaptation is significantly more efficient (~factor 8) when using this approach. | Adapting Software Quality Models: Practical Challenges, Approach, and
First Empirical Results | 5,831 |
Testing of software or software-based systems and services is considered as one of the most effort-consuming activities in the lifecycle. This applies especially to those domains where highly iterative development and continuous integration cannot be applied. Several approaches have been proposed to use measurement as a means to improve test effectiveness and efficiency. Most of them rely on using product data, historical data, or in-process data that is not related to quality assurance ac- tivities. Very few approaches use data from early quality assurance activities such as inspection data in order to focus testing activities and thereby reduce test effort. This article gives an overview of potential benefits of using data from early defect detection activities, potentially in addition to other data, in order to focus testing activities. In addition, the article sketches an integrated inspection and testing process and its evaluation in the context of two case studies. Taking the study limitations into account, the results show an overall reduction of testing effort by up to 34%, which mirrors an efficiency improvement of up to about 50% for testing. | Using Early Quality Assurance Metrics to Focus Testing Activities | 5,832 |
New ways of working such as globally distributed development or the integration of self-motivated external developers into software ecosystems will require a better and more comprehensive understanding of developers' feelings, perceptions, motivations and identification with their tasks in their respective project environments. User experience is a concept that captures how persons feel about products, systems and services. It evolved from disciplines such as interaction design and usability to a much richer scope that includes feelings, motivations, and satisfaction. Similarly, developer experience could be defined as a means for capturing how developers think and feel about their activities within their working environments, with the assumption that an improvement of the developer experience has positive impacts on characteristics such as sustained team and project performance. This article motivates the importance of developer experience, sketches related approaches from other domains, proposes a definition of developer experience that is derived from similar concepts in other domains, describes an ongoing empirical study to better understand developer experience, and finally gives an outlook on planned future research activities. | Developer Experience: Concept and Definition | 5,833 |
A Java File Security System (JFSS) [1] has been developed by us. That is an ecrypted file system. It is developed by us because there are so many file data breaches in the past and current history and they are going to increase day by day as the reports by DataLossDB (Open Security Foundation) organization, a non-profit organization in US so it is. The JFSS is evaluated regarding the two software engineering approaches. One of them is size metric that is Lines of Code (LOC) in the software product development. Another approach is the customer oriented namely User Satisfaction Testing methodology. Satisfying our customers is an essential element to stay in business in modern world of global competition. We must satisfy and even delight our customers with the value of our software products and services to gain their loyalty and repeat business. Customer satisfaction is therefore a primary goal of process improvement programs as well as quality predictions of our software. With the help of User Satisfaction Index that is calculated for many parameters regarding the customer satisfaction. Customer Satisfaction Surveys are the best way to find the satisfaction level of our product quality. | Java File Security System (JFSS) Evaluation Using Software Engineering
Approaches | 5,834 |
Regression Testing is exclusively executed to guarantee the desirable functionality of existing software after pursuing quite a few amendments or variations in it. Perhaps, it testifies the quality of the modified software by concealing the regressions or software bugs in both functional and non-functional applications of the system. In fact, the maintenance of test suite is enormous as it necessitates a big investment of time and money on test cases on a large scale. So, minimizing the test suite becomes the indispensable requisite to lessen the budget on regression testing. Precisely, this research paper aspires to present an innovative approach for the effective selection and prioritization of test cases which in return may procure a maximum code average. | Code Coverage Based Test Case Selection and Prioritization | 5,835 |
Software-as-a-Service (SaaS) is a viable option for some companies bearing their business processes. There is a considerable adoption rate, with companies already using more than two services for over two years. However, while some companies have plans to put more business processes supported by these services in the near future, others do not know if they will. They have several concerns regarding the software providers service level. These concerns are mainly technical and functional issues, service availability and payment models. There are major changes compared to the traditional software that have implications on how the software is developed and made available to the users. The existing research addresses specific aspects and few studies give a broader view of the implications of SaaS for anyone who develops and provides software, and also for those who consumes it as an end user. What are the real needs of the Portuguese market? What fears and what is being done to mitigate them? Where should we focus our attention related to the SaaS offering in order to create more value? Thus, to analyze these questions four exploratory case studiesare used to assess the possible implications of SaaS on software developers or software providers based in Portugal and also on end-users. This article appears in the context of a realistic and deep research that includes the involvement of managers, leaders and decision makers of Portuguese companies, to realize what actually constitutes a problem in SaaS and what effectively companies would like to have available in this offer. The results of this study reveal that SaaS effectively constitutes a very interesting and solid solution for the development of Portuguese companies, however there is a lack for greater efforts particularly in terms of customization for each customer (tenant) and integration with the back-end on-premise applications. | Business and technical requirements of Software-as-a-Service:
Implications in portuguese enterprise business context | 5,836 |
Risks and potential benefits of distributing software development projects globally depend to a large extent on how to allocate work to different development sites and regions. Existing methods in task allocation are likely to omit the relevance of considering a multitude of criteria and the impact of task distribution on risks and potential benefits. To assess risks stemming from specific work distributions and to exploit organization-specific experience, we have developed a customizable risk-driven model. It consists of two main steps: Suggesting a set of task allocation alternatives based on project- and site-specific characteristics and analyzing it with respect to possible project risks stemming from the work distribution. To evaluate the model, we conducted a series of semi-structured interviews in a multinational IT company. The results of the evaluation show that the suggestions of the model mostly comply with the retrospective views voiced by the involved experienced managers. | A Risk-driven Model for Work Allocation in Global Software Development
Projects | 5,837 |
Pattern plays a vital role in software architecture and it is a general reusable solution to commonly occurring problem. Software architecture of a system is the set of structures needed to reason about the system, which comprise software elements, relations among them, and properties of both. Patterns can be implemented at run-time; they identify key resource constraints and best practices. Architecture Pattern expresses a fundamental structural organization or schema for software systems. Patterns in software architecture, offer the promise of helping the architect to identify combinations of Architecture or Solution Building Blocks that have been proven to deliver effective solutions. In Internet banking, we analyzed some attributes such as reliability, security, availability, load balancing and so on. The use of patterns, which is of a reusable component, is a good tool to help designers build load balancing systems. In this paper we are going to propose pattern based adaptive architecture for internet banking system and so the above attributes can be improved by the usage of patterns. | Pattern Based Adaptive Architecture for Internet Banking | 5,838 |
This paper examines the four main types of Evolutionary Design by computers: Evolutionary Design Optimisation, Evolutionary Art, Evolutionary Artificial Life Forms and Creative Evolutionary Design. Definitions for all four areas are provided. A review of current work in each of these areas is given, with examples of the types of applications that have been tackled. The different properties and requirements of each are examined. Descriptions of typical representations and evolutionary algorithms are provided and examples of designs evolved using these techniques are shown. The paper then discusses how the boundaries of these areas are beginning to merge, resulting in four new 'overlapping' types of Evolutionary Design: Integral Evolutionary Design, Artificial Life Based Evolutionary Design, Aesthetic Evolutionary AL and Aesthetic Evolutionary Design. Finally, the last part of the paper discusses some common problems faced by creators of Evolutionary Design systems, including: interdependent elements in designs, epistasis, and constraint handling. | Aspects of Evolutionary Design by Computers | 5,839 |
A new training algorithm is presented for delayed reinforcement learning problems that does not assume the existence of a critic model and employs the polytope optimization algorithm to adjust the weights of the action network so that a simple direct measure of the training performance is maximized. Experimental results from the application of the method to the pole balancing problem indicate improved training performance compared with critic-based and genetic reinforcement approaches. | Training Reinforcement Neurocontrollers Using the Polytope Algorithm | 5,840 |
A mean field feedback artificial neural network algorithm is developed and explored for the set covering problem. A convenient encoding of the inequality constraints is achieved by means of a multilinear penalty function. An approximate energy minimum is obtained by iterating a set of mean field equations, in combination with annealing. The approach is numerically tested against a set of publicly available test problems with sizes ranging up to 5x10^3 rows and 10^6 columns. When comparing the performance with exact results for sizes where these are available, the approach yields results within a few percent from the optimal solutions. Comparisons with other approximate methods also come out well, in particular given the very low CPU consumption required -- typically a few seconds. Arbitrary problems can be processed using the algorithm via a public domain server. | An Efficient Mean Field Approach to the Set Covering Problem | 5,841 |
The process of evolutionary emergence of purposeful adaptive behavior is investigated by means of computer simulations. The model proposed implies that there is an evolving population of simple agents, which have two natural needs: energy and reproduction. Any need is characterized quantitatively by a corresponding motivation. Motivations determine goal-directed behavior of agents. The model demonstrates that purposeful behavior does emerge in the simulated evolutionary processes. Emergence of purposefulness is accompanied by origin of a simple hierarchy in the control system of agents. | Alife Model of Evolutionary Emergence of Purposeful Adaptive Behavior | 5,842 |
In general, we can not use algebraic or enumerative methods to optimize a quality control (QC) procedure so as to detect the critical random and systematic analytical errors with stated probabilities, while the probability for false rejection is minimum. Genetic algorithms (GAs) offer an alternative, as they do not require knowledge of the objective function to be optimized and search through large parameter spaces quickly. To explore the application of GAs in statistical QC, we have developed an interactive GAs based computer program that designs a novel near optimal QC procedure, given an analytical process. The program uses the deterministic crowding algorithm. An illustrative application of the program suggests that it has the potential to design QC procedures that are significantly better than 45 alternative ones that are used in the clinical laboratories. | Design of statistical quality control procedures using genetic
algorithms | 5,843 |
A new general procedure for a priori selection of more predictable events from a time series of observed variable is proposed. The procedure is applicable to time series which contains different types of events that feature significantly different predictability, or, in other words, to heteroskedastic time series. A priori selection of future events in accordance to expected uncertainty of their forecasts may be helpful for making practical decisions. The procedure first implies creation of two neural network based forecasting models, one of which is aimed at prediction of conditional mean and other - conditional dispersion, and then elaboration of the rule for future event selection into groups of more and less predictable events. The method is demonstrated and tested by the example of the computer generated time series, and then applied to the real world time series, Dow Jones Industrial Average index. | Selection of future events from a time series in relation to estimations
of forecasting uncertainty | 5,844 |
Ever increasing computational power will require methods for automatic programming. We present an alternative to genetic programming, based on a general model of thinking and learning. The advantage is that evolution takes place in the space of constructs and can thus exploit the mathematical structures of this space. The model is formalized, and a macro language is presented which allows for a formal yet intuitive description of the problem under consideration. A prototype has been developed to implement the scheme in PERL. This method will lead to a concentration on the analysis of problems, to a more rapid prototyping, to the treatment of new problem classes, and to the investigation of philosophical problems. We see fields of application in nonlinear differential equations, pattern recognition, robotics, model building, and animated pictures. | Thinking, Learning, and Autonomous Problem Solving | 5,845 |
GoTools is a program which solves life & death problems in the game of Go. This paper describes experiments using a Genetic Algorithm to optimize heuristic weights used by GoTools' tree-search. The complete set of heuristic weights is composed of different subgroups, each of which can be optimized with a suitable fitness function. As a useful side product, an MPI interface for FreePascal was implemented to allow the use of a parallelized fitness function running on a Beowulf cluster. The aim of this exercise is to optimize the current version of GoTools, and to make tools available in preparation of an extension of GoTools for solving open boundary life & death problems, which will introduce more heuristic parameters to be fine tuned. | Optimizing GoTools' Search Heuristics using Genetic Algorithms | 5,846 |
In the present paper a newer application of Artificial Neural Network (ANN) has been developed i.e., predicting response-function results of electrical-mechanical system through ANN. This method is specially useful to complex systems for which it is not possible to find the response-function because of complexity of the system. The proposed approach suggests that how even without knowing the response-function, the response-function results can be predicted with the use of ANN to the system. The steps used are: (i) Depending on the system, the ANN-architecture and the input & output parameters are decided, (ii) Training & test data are generated from simplified circuits and through tactic-superposition of it for complex circuits, (iii) Training the ANN with training data through many cycles and (iv) Test-data are used for predicting the response-function results. It is found that the proposed novel method for response prediction works satisfactorily. Thus this method could be used specially for complex systems where other methods are unable to tackle it. In this paper the application of ANN is particularly demonstrated to electrical-circuit system but can be applied to other systems too. | Predicting Response-Function Results of Electrical/Mechanical Systems
Through Artificial Neural Network | 5,847 |
We introduce a novel evolutionary formulation of the problem of finding a maximum independent set of a graph. The new formulation is based on the relationship that exists between a graph's independence number and its acyclic orientations. It views such orientations as individuals and evolves them with the aid of evolutionary operators that are very heavily based on the structure of the graph and its acyclic orientations. The resulting heuristic has been tested on some of the Second DIMACS Implementation Challenge benchmark graphs, and has been found to be competitive when compared to several of the other heuristics that have also been tested on those graphs. | A novel evolutionary formulation of the maximum independent set problem | 5,848 |
We introduce two novel evolutionary formulations of the problem of coloring the nodes of a graph. The first formulation is based on the relationship that exists between a graph's chromatic number and its acyclic orientations. It views such orientations as individuals and evolves them with the aid of evolutionary operators that are very heavily based on the structure of the graph and its acyclic orientations. The second formulation, unlike the first one, does not tackle one graph at a time, but rather aims at evolving a `program' to color all graphs belonging to a class whose members all have the same number of nodes and other common attributes. The heuristics that result from these formulations have been tested on some of the Second DIMACS Implementation Challenge benchmark graphs, and have been found to be competitive when compared to the several other heuristics that have also been tested on those graphs. | Two novel evolutionary formulations of the graph coloring problem | 5,849 |
This paper studies how the generalization ability of neurons can be affected by mutual processing of different signals. This study is done on the basis of a feedforward artificial neural network. The mutual processing of signals can possibly be a good model of patterns in a set generalized by a neural network and in effect may improve generalization. In this paper it is discussed that the interference may also cause a highly random generalization. Adaptive activation functions are discussed as a way of reducing that type of generalization. A test of a feedforward neural network is performed that shows the discussed random generalization. | On Interference of Signals and Generalization in Feedforward Neural
Networks | 5,850 |
In this paper, feedforward neural networks are presented that have nonlinear weight functions based on look--up tables, that are specially smoothed in a regularization called the diffusion. The idea of such a type of networks is based on the hypothesis that the greater number of adaptive parameters per a weight function might reduce the total number of the weight functions needed to solve a given problem. Then, if the computational complexity of a propagation through a single such a weight function would be kept low, then the introduced neural networks might possibly be relatively fast. A number of tests is performed, showing that the presented neural networks may indeed perform better in some cases than the classic neural networks and a number of other learning machines. | Feedforward Neural Networks with Diffused Nonlinear Weight Functions | 5,851 |
Websites of a particular class form increasingly complex networks, and new tools are needed to map and understand them. A way of visualizing this complex network is by mapping it. A map highlights which members of the community have similar interests, and reveals the underlying social network. In this paper, we will map a network of websites using Kohonen's self-organizing map (SOM), a neural-net like method generally used for clustering and visualization of complex data sets. The set of websites considered has been the Blogalia weblog hosting site (based at http://www.blogalia.com/), a thriving community of around 200 members, created in January 2002. In this paper we show how SOM discovers interesting community features, its relation with other community-discovering algorithms, and the way it highlights the set of communities formed over the network. | Mapping weblog communities | 5,852 |
This paper presents a parameter-less optimization framework that uses the extended compact genetic algorithm (ECGA) and iterated local search (ILS), but is not restricted to these algorithms. The presented optimization algorithm (ILS+ECGA) comes as an extension of the parameter-less genetic algorithm (GA), where the parameters of a selecto-recombinative GA are eliminated. The approach that we propose is tested on several well known problems. In the absence of domain knowledge, it is shown that ILS+ECGA is a robust and easy-to-use optimization method. | Parameter-less Optimization with the Extended Compact Genetic Algorithm
and Iterated Local Search | 5,853 |
This paper presents an architecture which is suitable for a massive parallelization of the compact genetic algorithm. The resulting scheme has three major advantages. First, it has low synchronization costs. Second, it is fault tolerant, and third, it is scalable. The paper argues that the benefits that can be obtained with the proposed approach is potentially higher than those obtained with traditional parallel genetic algorithms. In addition, the ideas suggested in the paper may also be relevant towards parallelizing more complex probabilistic model building genetic algorithms. | An architecture for massive parallelization of the compact genetic
algorithm | 5,854 |
This paper makes a number of connections between life and various facets of genetic and evolutionary algorithms research. Specifically, it addresses the topics of adaptation, multiobjective optimization, decision making, deception, and search operators, among others. It argues that human life, from birth to death, is an adaptive or dynamic optimization problem where people are continuously searching for happiness. More important, the paper speculates that genetic algorithms can be used as a source of inspiration for helping people make decisions in their everyday life. | A philosophical essay on life and its connections with genetic
algorithms | 5,855 |
Recently, researchers have applied genetic algorithms (GAs) to address some problems in quantum computation. Also, there has been some works in the designing of genetic algorithms based on quantum theoretical concepts and techniques. The so called Quantum Evolutionary Programming has two major sub-areas: Quantum Inspired Genetic Algorithms (QIGAs) and Quantum Genetic Algorithms (QGAs). The former adopts qubit chromosomes as representations and employs quantum gates for the search of the best solution. The later tries to solve a key question in this field: what GAs will look like as an implementation on quantum hardware? As we shall see, there is not a complete answer for this question. An important point for QGAs is to build a quantum algorithm that takes advantage of both the GA and quantum computing parallelism as well as true randomness provided by quantum computers. In the first part of this paper we present a survey of the main works in GAs plus quantum computing including also our works in this area. Henceforth, we review some basic concepts in quantum computation and GAs and emphasize their inherent parallelism. Next, we review the application of GAs for learning quantum operators and circuit design. Then, quantum evolutionary programming is considered. Finally, we present our current research in this field and some perspectives. | Genetic Algorithms and Quantum Computation | 5,856 |
This paper presents two different efficiency-enhancement techniques for probabilistic model building genetic algorithms. The first technique proposes the use of a mutation operator which performs local search in the sub-solution neighborhood identified through the probabilistic model. The second technique proposes building and using an internal probabilistic model of the fitness along with the probabilistic model of variable interactions. The fitness values of some offspring are estimated using the probabilistic model, thereby avoiding computationally expensive function evaluations. The scalability of the aforementioned techniques are analyzed using facetwise models for convergence time and population sizing. The speed-up obtained by each of the methods is predicted and verified with empirical results. The results show that for additively separable problems the competent mutation operator requires O(k 0.5 logm)--where k is the building-block size, and m is the number of building blocks--less function evaluations than its selectorecombinative counterpart. The results also show that the use of an internal probabilistic fitness model reduces the required number of function evaluations to as low as 1-10% and yields a speed-up of 2--50. | Efficiency Enhancement of Probabilistic Model Building Genetic
Algorithms | 5,857 |
This paper analyzes the relative advantages between crossover and mutation on a class of deterministic and stochastic additively separable problems. This study assumes that the recombination and mutation operators have the knowledge of the building blocks (BBs) and effectively exchange or search among competing BBs. Facetwise models of convergence time and population sizing have been used to determine the scalability of each algorithm. The analysis shows that for additively separable deterministic problems, the BB-wise mutation is more efficient than crossover, while the crossover outperforms the mutation on additively separable problems perturbed with additive Gaussian noise. The results show that the speed-up of using BB-wise mutation on deterministic problems is O(k^{0.5}logm), where k is the BB size, and m is the number of BBs. Likewise, the speed-up of using crossover on stochastic problems with fixed noise variance is O(mk^{0.5}log m). | Let's Get Ready to Rumble: Crossover Versus Mutation Head to Head | 5,858 |
This paper presents a competent selectomutative genetic algorithm (GA), that adapts linkage and solves hard problems quickly, reliably, and accurately. A probabilistic model building process is used to automatically identify key building blocks (BBs) of the search problem. The mutation operator uses the probabilistic model of linkage groups to find the best among competing building blocks. The competent selectomutative GA successfully solves additively separable problems of bounded difficulty, requiring only subquadratic number of function evaluations. The results show that for additively separable problems the probabilistic model building BB-wise mutation scales as O(2^km^{1.5}), and requires O(k^{0.5}logm) less function evaluations than its selectorecombinative counterpart, confirming theoretical results reported elsewhere (Sastry & Goldberg, 2004). | Designing Competent Mutation Operators via Probabilistic Model Building
of Neighborhoods | 5,859 |
This paper studies fitness inheritance as an efficiency enhancement technique for a class of competent genetic algorithms called estimation distribution algorithms. Probabilistic models of important sub-solutions are developed to estimate the fitness of a proportion of individuals in the population, thereby avoiding computationally expensive function evaluations. The effect of fitness inheritance on the convergence time and population sizing are modeled and the speed-up obtained through inheritance is predicted. The results show that a fitness-inheritance mechanism which utilizes information on building-block fitnesses provides significant efficiency enhancement. For additively separable problems, fitness inheritance reduces the number of function evaluations to about half and yields a speed-up of about 1.75--2.25. | Efficiency Enhancement of Genetic Algorithms via Building-Block-Wise
Fitness Estimation | 5,860 |
In this paper we apply a heuristic method based on artificial neural networks in order to trace out the efficient frontier associated to the portfolio selection problem. We consider a generalization of the standard Markowitz mean-variance model which includes cardinality and bounding constraints. These constraints ensure the investment in a given number of different assets and limit the amount of capital to be invested in each asset. We present some experimental results obtained with the neural network heuristic and we compare them to those obtained with three previous heuristic methods. | Portfolio selection using neural networks | 5,861 |
This article presents the Neo-Fuzzy-Neuron Modified by Kohonen Network (NFN-MK), an hybrid computational model that combines fuzzy system technique and artificial neural networks. Its main task consists in the automatic generation of membership functions, in particular, triangle forms, aiming a dynamic modeling of a system. The model is tested by simulating real systems, here represented by a nonlinear mathematical function. Comparison with the results obtained by traditional neural networks, and correlated studies of neurofuzzy systems applied in system identification area, shows that the NFN-MK model has a similar performance, despite its greater simplicity. | Obtaining Membership Functions from a Neuron Fuzzy System extended by
Kohonen Network | 5,862 |
We describe a new neural-network technique developed for an automated recognition of solar filaments visible in the hydrogen H-alpha line full disk spectroheliograms. This technique allows neural networks learn from a few image fragments labelled manually to recognize the single filaments depicted on a local background. The trained network is able to recognize filaments depicted on the backgrounds with variations in brightness caused by atmospherics distortions. Despite the difference in backgrounds in our experiments the neural network has properly recognized filaments in the testing image fragments. Using a parabolic activation function we extend this technique to recognize multiple solar filaments which may appear in one fragment. | A Neural-Network Technique for Recognition of Filaments in Solar Images | 5,863 |
The Hopfield network has been applied to solve optimization problems over decades. However, it still has many limitations in accomplishing this task. Most of them are inherited from the optimization algorithms it implements. The computation of a Hopfield network, defined by a set of difference equations, can easily be trapped into one local optimum or another, sensitive to initial conditions, perturbations, and neuron update orders. It doesn't know how long it will take to converge, as well as if the final solution is a global optimum, or not. In this paper, we present a Hopfield network with a new set of difference equations to fix those problems. The difference equations directly implement a new powerful optimization algorithm. | A New Kind of Hopfield Networks for Finding Global Optimum | 5,864 |
The recognition of optical characters is known to be one of the earliest applications of Artificial Neural Networks, which partially emulate human thinking in the domain of artificial intelligence. In this paper, a simplified neural approach to recognition of optical or visual characters is portrayed and discussed. The document is expected to serve as a resource for learners and amateur investigators in pattern recognition, neural networking and related disciplines. | Visual Character Recognition using Artificial Neural Networks | 5,865 |
The Artificial Neural network is a functional imitation of simplified model of the biological neurons and their goal is to construct useful computers for real world problems. The ANN applications have increased dramatically in the last few years fired by both theoretical and practical applications in a wide variety of applications. A brief theory of ANN is presented and potential areas are identified and future trends are discussed. | Artificial Neural Networks and their Applications | 5,866 |
This paper discusses the notion of generalization of training samples over long distances in the input space of a feedforward neural network. Such a generalization might occur in various ways, that differ in how great the contribution of different training features should be. The structure of a neuron in a feedforward neural network is analyzed and it is concluded, that the actual performance of the discussed generalization in such neural networks may be problematic -- while such neural networks might be capable for such a distant generalization, a random and spurious generalization may occur as well. To illustrate the differences in generalizing of the same function by different learning machines, results given by the support vector machines are also presented. | Distant generalization by feedforward neural networks | 5,867 |
A dissipative particle swarm optimization is developed according to the self-organization of dissipative structure. The negative entropy is introduced to construct an opening dissipative system that is far-from-equilibrium so as to driving the irreversible evolution process with better fitness. The testing of two multimodal functions indicates it improves the performance effectively | A dissipative particle swarm optimization | 5,868 |
A self-organizing particle swarm is presented. It works in dissipative state by employing the small inertia weight, according to experimental analysis on a simplified model, which with fast convergence. Then by recognizing and replacing inactive particles according to the process deviation information of device parameters, the fluctuation is introduced so as to driving the irreversible evolution process with better fitness. The testing on benchmark functions and an application example for device optimization with designed fitness function indicates it improves the performance effectively. | Optimizing semiconductor devices by self-organizing particle swarm | 5,869 |
The adaptive constraints relaxing rule for swarm algorithms to handle with the problems with equality constraints is presented. The feasible space of such problems may be similiar to ridge function class, which is hard for applying swarm algorithms. To enter the solution space more easily, the relaxed quasi feasible space is introduced and shrinked adaptively. The experimental results on benchmark functions are compared with the performance of other algorithms, which show its efficiency. | Handling equality constraints by adaptive relaxing rule for swarm
algorithms | 5,870 |
The periodic mode is analyzed together with two conventional boundary handling modes for particle swarm. By providing an infinite space that comprises periodic copies of original search space, it avoids possible disorganizing of particle swarm that is induced by the undesired mutations at the boundary. The results on benchmark functions show that particle swarm with periodic mode is capable of improving the search performance significantly, by compared with that of conventional modes and other algorithms. | Handling boundary constraints for numerical optimization by particle
swarm flying in periodic search space | 5,871 |
A swarm algorithm framework (SWAF), realized by agent-based modeling, is presented to solve numerical optimization problems. Each agent is a bare bones cognitive architecture, which learns knowledge by appropriately deploying a set of simple rules in fast and frugal heuristics. Two essential categories of rules, the generate-and-test and the problem-formulation rules, are implemented, and both of the macro rules by simple combination and subsymbolic deploying of multiple rules among them are also studied. Experimental results on benchmark problems are presented, and performance comparison between SWAF and other existing algorithms indicates that it is efficiently. | SWAF: Swarm Algorithm Framework for Numerical Optimization | 5,872 |
Routing, as a basic phenomena, by itself, has got umpteen scopes to analyse, discuss and arrive at an optimal solution for the technocrats over years. Routing is analysed based on many factors; few key constraints that decide the factors are communication medium, time dependency, information source nature. Parametric routing has become the requirement of the day, with some kind of adaptation to the underlying network environment. Satellite constellations, particularly LEO satellite constellations have become a reality in operational to have a non-breaking voice/data communication around the world.Routing in these constellations has to be treated in a non conventional way, taking their network geometry into consideration. One of the efficient methods of optimization is putting Neural Networks to use. Few Artificial Neural Network models are very much suitable for the adaptive control mechanism, by their nature of network arrangement. One such efficient model is Hopfield Network model. This paper is an attempt to design a framework for the Hopfield Network based adaptive routing phenomena in satellite constellations. | Framework for Hopfield Network based Adaptive routing - A design level
approach for adaptive routing phenomena with Artificial Neural Network | 5,873 |
We posit a new paradigm for image information processing. For the last 25 years, this task was usually approached in the frame of Treisman's two-stage paradigm [1]. The latter supposes an unsupervised, bottom-up directed process of preliminary information pieces gathering at the lower processing stages and a supervised, top-down directed process of information pieces binding and grouping at the higher stages. It is acknowledged that these sub-processes interact and intervene between them in a tricky and a complicated manner. Notwithstanding the prevalence of this paradigm in biological and computer vision, we nevertheless propose to replace it with a new one, which we would like to designate as a two-part paradigm. In it, information contained in an image is initially extracted in an independent top-down manner by one part of the system, and then it is examined and interpreted by another, separate system part. We argue that the new paradigm seems to be more plausible than its forerunner. We provide evidence from human attention vision studies and insights of Kolmogorov's complexity theory to support our arguments. We also provide some reasons in favor of separate image interpretation issues. | Does a Plane Imitate a Bird? Does Computer Vision Have to Follow
Biological Paradigms? | 5,874 |
An operator algebra implementation of Markov chain Monte Carlo algorithms for simulating Markov random fields is proposed. It allows the dynamics of networks whose nodes have discrete state spaces to be specified by the action of an update operator that is composed of creation and annihilation operators. This formulation of discrete network dynamics has properties that are similar to those of a quantum field theory of bosons, which allows reuse of many conceptual and theoretical structures from QFT. The equilibrium behaviour of one of these generalised MRFs and of the adaptive cluster expansion network (ACEnet) are shown to be equivalent, which provides a way of unifying these two theories. | Discrete Network Dynamics. Part 1: Operator Theory | 5,875 |
Traditional Support Vector Machines (SVMs) need pre-wired finite time windows to predict and classify time series. They do not have an internal state necessary to deal with sequences involving arbitrary long-term dependencies. Here we introduce a new class of recurrent, truly sequential SVM-like devices with internal adaptive states, trained by a novel method called EVOlution of systems with KErnel-based outputs (Evoke), an instance of the recent Evolino class of methods. Evoke evolves recurrent neural networks to detect and represent temporal dependencies while using quadratic programming/support vector regression to produce precise outputs. Evoke is the first SVM-based mechanism learning to classify a context-sensitive language. It also outperforms recent state-of-the-art gradient-based recurrent neural networks (RNNs) on various time series prediction tasks. | Evolino for recurrent support vector machines | 5,876 |
We exhibit a family of neural networks of McCulloch and Pitts of size $2nk+2$ which can be simulated by a neural networks of Caianiello of size $2n+2$ and memory length $k$. This simulation allows us to find again one of the result of the following article: [Cycles exponentiels des r\'{e}seaux de Caianiello et compteurs en arithm\'{e}tique redondante, Technique et Science Informatiques Vol. 19, pages 985-1008] on the existence of neural networks of Caianiello of size $2n+2$ and memory length $k$ which describes a cycle of length $k \times 2^{nk}$. | Réseaux d'Automates de Caianiello Revisité | 5,877 |
This paper looks in detail at how an evolutionary algorithm attempts to solve instances from the multimodal problem generator. The paper shows that in order to consistently reach the global optimum, an evolutionary algorithm requires a population size that should grow at least linearly with the number of peaks. It is also shown a close relationship between the supply and decision making issues that have been identified previously in the context of population sizing models for additively decomposable problems. The most important result of the paper, however, is that solving an instance of the multimodal problem generator is like solving a peak-in-a-haystack, and it is argued that evolutionary algorithms are not the best algorithms for such a task. Finally, and as opposed to what several researchers have been doing, it is our strong belief that the multimodal problem generator is not adequate for assessing the performance of evolutionary algorithms. | On the utility of the multimodal problem generator for assessing the
performance of Evolutionary Algorithms | 5,878 |
In an evolutionary algorithm, the population has a very important role as its size has direct implications regarding solution quality, speed, and reliability. Theoretical studies have been done in the past to investigate the role of population sizing in evolutionary algorithms. In addition to those studies, several self-adjusting population sizing mechanisms have been proposed in the literature. This paper revisits the latter topic and pays special attention to the genetic algorithm with adaptive population size (APGA), for which several researchers have claimed to be very effective at autonomously (re)sizing the population. As opposed to those previous claims, this paper suggests a complete opposite view. Specifically, it shows that APGA is not capable of adapting the population size at all. This claim is supported on theoretical grounds and confirmed by computer simulations. | Revisiting Evolutionary Algorithms with On-the-Fly Population Size
Adjustment | 5,879 |
Hybrid neuro-evolutionary algorithms may be inspired on Darwinian or Lamarckian evolu- tion. In the case of Darwinian evolution, the Baldwin effect, that is, the progressive incorporation of learned characteristics to the genotypes, can be observed and leveraged to improve the search. The purpose of this paper is to carry out an exper- imental study into how learning can improve G-Prop genetic search. Two ways of combining learning and genetic search are explored: one exploits the Baldwin effect, while the other uses a Lamarckian strategy. Our experiments show that using a Lamarckian op- erator makes the algorithm find networks with a low error rate, and the smallest size, while using the Bald- win effect obtains MLPs with the smallest error rate, and a larger size, taking longer to reach a solution. Both approaches obtain a lower average error than other BP-based algorithms like RPROP, other evolu- tionary methods and fuzzy logic based methods | Lamarckian Evolution and the Baldwin Effect in Evolutionary Neural
Networks | 5,880 |
The Kak family of neural networks is able to learn patterns quickly, and this speed of learning can be a decisive advantage over other competing models in many applications. Amongst the implementations of these networks are those using reconfigurable networks, FPGAs and optical networks. In some applications, it is useful to use complex data, and it is with that in mind that this introduction to the basic Kak network with complex inputs is being presented. The training algorithm is prescriptive and the network weights are assigned simply upon examining the inputs. The input is mapped using quaternary encoding for purpose of efficienty. This network family is part of a larger hierarchy of learning schemes that include quantum models. | The Basic Kak Neural Network with Complex Inputs | 5,881 |
A method of autonomic face recognition based on the biologically plausible network of networks (NoN) model of information processing is presented. The NoN model is based on locally parallel and globally coordinated transformations in which the neurons or computational units form distributed networks, which themselves link to form larger networks. This models the structures in the cerebral cortex described by Mountcastle and the architecture based on that proposed for information processing by Sutton. In the proposed implementation, face images are processed by a nested family of locally operating networks along with a hierarchically superior network that classifies the information from each of the local networks. The results of the experiments yielded a maximum of 98.5% recognition accuracy and an average of 97.4% recognition accuracy on a benchmark database. | The NoN Approach to Autonomic Face Recognition | 5,882 |
Many real world data are sampled functions. As shown by Functional Data Analysis (FDA) methods, spectra, time series, images, gesture recognition data, etc. can be processed more efficiently if their functional nature is taken into account during the data analysis process. This is done by extending standard data analysis methods so that they can apply to functional inputs. A general way to achieve this goal is to compute projections of the functional data onto a finite dimensional sub-space of the functional space. The coordinates of the data on a basis of this sub-space provide standard vector representations of the functions. The obtained vectors can be processed by any standard method. In our previous work, this general approach has been used to define projection based Multilayer Perceptrons (MLPs) with functional inputs. We study in this paper important theoretical properties of the proposed model. We show in particular that MLPs with functional inputs are universal approximators: they can approximate to arbitrary accuracy any continuous mapping from a compact sub-space of a functional space to R. Moreover, we provide a consistency result that shows that any mapping from a functional space to R can be learned thanks to examples by a projection based MLP: the generalization mean square error of the MLP decreases to the smallest possible mean square error on the data when the number of examples goes to infinity. | Theoretical Properties of Projection Based Multilayer Perceptrons with
Functional Inputs | 5,883 |
This paper introduces an objective function that seeks to minimise the average total number of bits required to encode the joint state of all of the layers of a Markov source. This type of encoder may be applied to the problem of optimising the bottom-up (recognition model) and top-down (generative model) connections in a multilayer neural network, and it unifies several previous results on the optimisation of multilayer neural networks. | Modelling the Probability Density of Markov Sources | 5,884 |
This article investigates Kak neural networks, which can be instantaneously trained, for complex and quaternion inputs. The performance of the basic algorithm has been analyzed and shown how it provides a plausible model of human perception and understanding of images. The motivation for studying quaternion inputs is their use in representing spatial rotations that find applications in computer graphics, robotics, global navigation, computer vision and the spatial orientation of instruments. The problem of efficient mapping of data in quaternion neural networks is examined. Some problems that need to be addressed before quaternion neural networks find applications are identified. | Neural Networks with Complex and Quaternion Inputs | 5,885 |
In this paper we present a novel tool to evaluate problem solving systems. Instead of using a system to solve a problem, we suggest using the problem to evaluate the system. By finding a numerical representation of a problem's complexity, one can implement genetic algorithm to search for the most complex problem the given system can solve. This allows a comparison between different systems that solve the same set of problems. In this paper we implement this approach on pattern recognition neural networks to try and find the most complex pattern a given configuration can solve. The complexity of the pattern is calculated using linguistic complexity. The results demonstrate the power of the problem evolution approach in ranking different neural network configurations according to their pattern recognition abilities. Future research and implementations of this technique are also discussed. | Problem Evolution: A new approach to problem solving systems | 5,886 |
Some visual search tasks require to memorize the location of stimuli that have been previously scanned. Considerations about the eye movements raise the question of how we are able to maintain a coherent memory, despite the frequent drastically changes in the perception. In this article, we present a computational model that is able to anticipate the consequences of the eye movements on the visual perception in order to update a spatial memory | A Computational Model of Spatial Memory Anticipation during Visual
Search | 5,887 |
We consider flocks of artificial birds and study the emergence of V-like formations during flight. We introduce a small set of fully distributed positioning rules to guide the birds' movements and demonstrate, by means of simulations, that they tend to lead to stabilization into several of the well-known V-like formations that have been observed in nature. We also provide quantitative indicators that we believe are closely related to achieving V-like formations, and study their behavior over a large set of independent simulations. | V-like formations in flocks of artificial birds | 5,888 |
The random initialization of weights of a multilayer perceptron makes it possible to model its training process as a Las Vegas algorithm, i.e. a randomized algorithm which stops when some required training error is obtained, and whose execution time is a random variable. This modeling is used to perform a case study on a well-known pattern recognition benchmark: the UCI Thyroid Disease Database. Empirical evidence is presented of the training time probability distribution exhibiting a heavy tail behavior, meaning a big probability mass of long executions. This fact is exploited to reduce the training time cost by applying two simple restart strategies. The first assumes full knowledge of the distribution yielding a 40% cut down in expected time with respect to the training without restarts. The second, assumes null knowledge, yielding a reduction ranging from 9% to 23%. | Exploiting Heavy Tails in Training Times of Multilayer Perceptrons: A
Case Study with the UCI Thyroid Disease Database | 5,889 |
When looking for a solution, deterministic methods have the enormous advantage that they do find global optima. Unfortunately, they are very CPU-intensive, and are useless on untractable NP-hard problems that would require thousands of years for cutting-edge computers to explore. In order to get a result, one needs to revert to stochastic algorithms, that sample the search space without exploring it thoroughly. Such algorithms can find very good results, without any guarantee that the global optimum has been reached; but there is often no other choice than using them. This chapter is a short introduction to the main methods used in stochastic optimization. | Stochastic Optimization Algorithms | 5,890 |
The assessment of highly-risky situations at road intersections have been recently revealed as an important research topic within the context of the automotive industry. In this paper we shall introduce a novel approach to compute risk functions by using a combination of a highly non-linear processing model in conjunction with a powerful information encoding procedure. Specifically, the elements of information either static or dynamic that appear in a road intersection scene are encoded by using directed positional acyclic labeled graphs. The risk assessment problem is then reformulated in terms of an inductive learning task carried out by a recursive neural network. Recursive neural networks are connectionist models capable of solving supervised and non-supervised learning problems represented by directed ordered acyclic graphs. The potential of this novel approach is demonstrated through well predefined scenarios. The major difference of our approach compared to others is expressed by the fact of learning the structure of the risk. Furthermore, the combination of a rich information encoding procedure with a generalized model of dynamical recurrent networks permit us, as we shall demonstrate, a sophisticated processing of information that we believe as being a first step for building future advanced intersection safety systems | Risk Assessment Algorithms Based On Recursive Neural Networks | 5,891 |
The Boolean satisfiability problem (SAT) can be solved efficiently with variants of the DPLL algorithm. For industrial SAT problems, DPLL with conflict analysis dependent dynamic decision heuristics has proved to be particularly efficient, e.g. in Chaff. In this work, algorithms that initialize the variable activity values in the solver MiniSAT v1.14 by analyzing the CNF are evolved using genetic programming (GP), with the goal to reduce the total number of conflicts of the search and the solving time. The effect of using initial activities other than zero is examined by initializing with random numbers. The possibility of countering the detrimental effects of reordering the CNF with improved initialization is investigated. The best result found (with validation testing on further problems) was used in the solver Actin, which was submitted to SAT-Race 2006. | Actin - Technical Report | 5,892 |
Neural network models of real-world systems, such as industrial processes, made from sensor data must often rely on incomplete data. System states may not all be known, sensor data may be biased or noisy, and it is not often known which sensor data may be useful for predictive modelling. Genetic algorithms may be used to help to address this problem by determining the near optimal subset of sensor variables most appropriate to produce good models. This paper describes the use of genetic search to optimize variable selection to determine inputs into the neural network model. We discuss genetic algorithm implementation issues including data representation types and genetic operators such as crossover and mutation. We present the use of this technique for neural network modelling of a typical industrial application, a liquid fed ceramic melter, and detail the results of the genetic search to optimize the neural network model for this application. | Improved Neural Modeling of Real-World Systems Using Genetic Algorithm
Based Variable Selection | 5,893 |
Although there are some real world applications where the use of variable length representation (VLR) in Evolutionary Algorithm is natural and suitable, an academic framework is lacking for such representations. In this work we propose a family of tunable fitness landscapes based on VLR of genotypes. The fitness landscapes we propose possess a tunable degree of both neutrality and epistasis; they are inspired, on the one hand by the Royal Road fitness landscapes, and the other hand by the NK fitness landscapes. So these landscapes offer a scale of continuity from Royal Road functions, with neutrality and no epistasis, to landscapes with a large amount of epistasis and no redundancy. To gain insight into these fitness landscapes, we first use standard tools such as adaptive walks and correlation length. Second, we evaluate the performances of evolutionary algorithms on these landscapes for various values of the neutral and the epistatic parameters; the results allow us to correlate the performances with the expected degrees of neutrality and epistasis. | From Royal Road to Epistatic Road for Variable Length Evolution
Algorithm | 5,894 |
Usually the offspring-parent fitness correlation is used to visualize and analyze some caracteristics of fitness landscapes such as evolvability. In this paper, we introduce a more general representation of this correlation, the Fitness Cloud (FC). We use the bottleneck metaphor to emphasise fitness levels in landscape that cause local search process to slow down. For a local search heuristic such as hill-climbing or simulated annealing, FC allows to visualize bottleneck and neutrality of landscapes. To confirm the relevance of the FC representation we show where the bottlenecks are in the well-know NK fitness landscape and also how to use neutrality information from the FC to combine some neutral operator with local search heuristic. | Where are Bottlenecks in NK Fitness Landscapes? | 5,895 |
We proposed a new search heuristic using the scuba diving metaphor. This approach is based on the concept of evolvability and tends to exploit neutrality in fitness landscape. Despite the fact that natural evolution does not directly select for evolvability, the basic idea behind the scuba search heuristic is to explicitly push the evolvability to increase. The search process switches between two phases: Conquest-of-the-Waters and Invasion-of-the-Land. A comparative study of the new algorithm and standard local search heuristics on the NKq-landscapes has shown advantage and limit of the scuba search. To enlighten qualitative differences between neutral search processes, the space is changed into a connected graph to visualize the pathways that the search is likely to follow. | Scuba Search : when selection meets innovation | 5,896 |
We proposed a new search heuristic using the scuba diving metaphor. This approach is based on the concept of evolvability and tends to exploit neutrality which exists in many real-world problems. Despite the fact that natural evolution does not directly select for evolvability, the basic idea behind the scuba search heuristic is to explicitly push evolvability to increase. A comparative study of the scuba algorithm and standard local search heuristics has shown the advantage and the limitation of the scuba search. In order to tune neutrality, we use the NKq fitness landscapes and a family of travelling salesman problems (TSP) where cities are randomly placed on a lattice and where travel distance between cities is computed with the Manhattan metric. In this last problem the amount of neutrality varies with the city concentration on the grid ; assuming the concentration below one, this TSP reasonably remains a NP-hard problem. | How to use the Scuba Diving metaphor to solve problem with neutrality ? | 5,897 |
This work exposes which mechanisms and procesess in the Nature of evolution compute a function not computable by Turing machine. The computer with intelligence that is not higher than one bacteria population could have, but with efficency to solve the problems that are non-computable by Turing machine is represented. This theoretical construction is called Universal Evolutinary Computer and it is based on the superecursive algorithms of evolvability. | The universal evolutionary computer based on super-recursive algorithms
of evolvability | 5,898 |
Functional Data Analysis (FDA) is an extension of traditional data analysis to functional data, for example spectra, temporal series, spatio-temporal images, gesture recognition data, etc. Functional data are rarely known in practice; usually a regular or irregular sampling is known. For this reason, some processing is needed in order to benefit from the smooth character of functional data in the analysis methods. This paper shows how to extend the Radial-Basis Function Networks (RBFN) and Multi-Layer Perceptron (MLP) models to functional data inputs, in particular when the latter are known through lists of input-output pairs. Various possibilities for functional processing are discussed, including the projection on smooth bases, Functional Principal Component Analysis, functional centering and reduction, and the use of differential operators. It is shown how to incorporate these functional processing into the RBFN and MLP models. The functional approach is illustrated on a benchmark of spectrometric data analysis. | Representation of Functional Data in Neural Networks | 5,899 |
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