OpenRaiser/Intern-Atlas huggingface dataset:
On terminating improvement in two-player games
Venue: arXiv cs.GT 2014
Year: 2014

A real-valued game has the finite improvement property (FIP), if starting from an arbitrary strategy profile and letting the players change strategies to increase their individual payoffs in a sequential but non-deterministic order always reaches a Nash equilibrium. E.g., potential games have the FIP. Many of them have the FIP by chance nonetheless, since modifying even a single payoff may ruin the property. This article characterises (in quadratic time) the class of the finite games where FIP not only holds but is also preserved when modifying all the occurrences of an arbitrary payoff. The characterisation relies on a pattern-matching sufficient condition for games (finite or infinite) to enjoy the FIP, and is followed by an inductive description of this class. A real-valued game is weakly acyclic if the improvement described above can reach a Nash equilibrium. This article characterises the finite such games using Markov chains and almost sure convergence to equilibrium. It also gives an inductive description of the two-player such games.
Scalable Density-Based Distributed Clustering
Venue: arXiv cs.DB 2014
Year: 2014

Clustering has become an increasingly important task in analysing huge amounts of data. Traditional applications require that all data has to be located at the site where it is scrutinized. Nowadays, large amounts of heterogeneous, complex data reside on different, independently working computers which are connected to each other via local or wide area networks. In this paper, we propose a scalable density-based distributed clustering algorithm which allows a user-defined trade-off between clustering quality and the number of transmitted objects from the different local sites to a global server site. Our approach consists of the following steps: First, we order all objects located at a local site according to a quality criterion reflecting their suitability to serve as local representatives. Then we send the best of these representatives to a server site where they are clustered with a slightly enhanced density-based clustering algorithm. This approach is very efficient, because the local detemination of suitable representatives can be carried out quickly and independently from each other. Furthermore, based on the scalable number of the most suitable local representatives, the global clustering can be done very effectively and efficiently. In our experimental evaluation, we will show that our new scalable density-based distributed clustering approach results in high quality clusterings with scalable transmission cost.
MontiArc - Architectural Modeling of Interactive Distributed and Cyber-Physical Systems
Venue: arXiv cs.SE 2014
Year: 2014

This report presents MontiArc, a modeling language for the description of Component & Connector architectures. A component is a unit executing computations and/or storing data. Information flow between components is modeled via unidirectional connectors connecting typed, directed ports of the interfaces of components. Language features of the ADL MontiArc include hierarchical decomposition of components, subtyping by structural inheritance, component type definitions and reference declarations for reuse, generic component types and configurable components, syntactic sugar for connectors, and controlled implicit creation of connections and subcomponent declarations. This technical report gives an overview of the MontiArc language and is a reference for the MontiArc grammar intended to enable reuse and extension of MontiArc and MontiArc related tools. MontiArc is implemented using the DSL framework MontiCore. Available tools include an editor with syntax highlighting and code completion as well as a simulation framework with a Java code generator.
Scaling-Up Model-Based-Development for Large Heterogeneous Systems with Compositional Modeling
Venue: arXiv cs.SE 2014
Year: 2014

Model-based development and in particular MDA [1], [2] have promised to be especially suited for the development of complex, heterogeneous, and large software systems. However, so far MDA has failed to fulfill this promise to a larger extent because of tool support being inadequate and clumsy and methodologies not being appropriate for an effective development. This article discusses what went wrong in current MDA approaches and what needs to be done to make MDA suited for ultra-large, distributed systems.
Orchestration of Global Software Engineering Projects
Venue: arXiv cs.SE 2014
Year: 2014

Global software engineering has become a fact in many companies due to real necessity in practice. In contrast to co-located projects global projects face a number of additional software engineering challenges. Among them quality management has become much more difficult and schedule and budget overruns can be observed more often. Compared to co-located projects global software engineering is even more challenging due to the need for integration of different cultures, different languages, and different time zones - across companies, and across countries. The diversity of development locations on several levels seriously endangers an effective and goal-oriented progress of projects. In this position paper we discuss reasons for global development, sketch settings for distribution and views of orchestration of dislocated companies in a global project that can be seen as a "virtual project environment". We also present a collection of questions, which we consider relevant for global software engineering. The questions motivate further discussion to derive a research agenda in global software engineering.
Assessing usability of model driven development in industrial projects
Venue: arXiv cs.SE 2014
Year: 2014

An integral use of the model driven development paradigm influences and changes an organization's software development division rather heavily. Such a paradigm reduces some tasks in complexity and costs, but also introduces new tasks and, if introduced seriously, has severe affects on activities and roles in the software development process. As the model becomes the most important development artifact, there are new challenges to the development team, e. g. assessing the model's quality, model partitioning and configuration management for distributed teams, setup of build management, tool chaining and tracing of information through the various artifacts. Organizations coping with model driven development need to successfully introduce new tools and new ways of thinking, they are challenged in adopting their processes and training their staff. This paper presents an ongoing research project on the assessment of the usability of modeling and model driven development at a global industrial organization with its headquarters in Germany. The matter of interest is the analysis of the usability of modeling (especially with the UML) and model driven development by accomplishing an empirical, quantitative survey.
Scaling the Management of Extreme Programming Projects
Venue: arXiv cs.SE 2014
Year: 2014

XP is a code-oriented, light-weight software engineering methodology, suited merely for small-sized teams who develop software that relies on vague or rapidly changing requirements. Being very code-oriented, the discipline of systems engineering knows it as approach of incremental system change. In this contribution, we discuss the enhanced version of a concept on how to extend XP on large scale projects with hundreds of software engineers and programmers, respectively. Previous versions were already presented in [1] and [12]. The basic idea is to apply the "hierarchical approach", a management principle of reorganizing companies, as well as well-known moderation principles to XP project organization. We show similarities between software engineering methods and company reorganization processes and discuss how the elements of the hierarchical approach can improve XP. We provide guidelines on how to scale up XP to very large projects e.g. those common in telecommunication industry and IT technology consultancy firms by using moderation techniques.
Assumptions Underlying Agile Software Development Processes
Venue: arXiv cs.SE 2014
Year: 2014

Agile processes focus on facilitating early and fast production of working code, and are based on software development process models that support iterative, incremental development of software. Although agile methods have existed for a number of years now, answers to questions concerning the suitability of agile processes to particular software development environments are still often based on anecdotal accounts of experiences. An appreciation of the (often unstated) assumptions underlying agile processes can lead to a better understanding of the applicability of agile processes to particular situations. Agile processes are less likely to be applicable in situations in which core assumptions do not hold. This paper examines the principles and advocated practices of agile processes to identify underlying assumptions. The paper also identifies limitations that may arise from these assumptions and outlines how the limitations can be addresses by incorporating other software development techniques and practices into agile development environments.
Agile Test-based Modeling
Venue: arXiv cs.SE 2014
Year: 2014

Model driven architecture (MDA) concentrates on the use of models during software development. An approach using models as the central development artifact is more abstract, more compact and thus more effective and probably also less error prone. Although the ideas of MDA exist already for years, there is still much to improve in the development process as well as the underlying techniques and tools. Therefore, this paper is a follow up on, reexamining und updating the statements made there. Here two major and strongly related techniques are identified and discussed: Test case modeling and an evolutionary approach to model transformation.
An Algebraic View on the Semantics of model Composition
Venue: arXiv cs.SE 2014
Year: 2014

Due to the increased complexity of software development projects more and more systems are described by models. The sheer size makes it impractical to describe these systems by a single model. Instead many models are developed that provide several complementary views on the system to be developed. This however leads to a need for compositional models. This paper describes a foundational theory of model composition in form of an algebra to explicitly clarify different variants and uses of composition, their interplay with the semantics of the involved models and their composition operators.
View-Centric Modeling of Automotive Logical Architectures
Venue: arXiv cs.SE 2014
Year: 2014

Modeling the logical architecture is an often underestimated development step to gain an early insight into the fundamental functional properties of an automotive system. An architectural description supports developers in making design decisions for further development steps like the refinement towards a software architecture or the partition of logical functions on ECUs and buses. However, due to the large size and complexity of the system and hence the logical architecture, a good notation, method, and tooling is necessary. In this paper, we show how the logical architectures can be modeled succinctly as function nets using a SysML-based notation. The usefulness for developers is increased by comprehensible views on the complete model to describe automotive features in a self contained way including their variants, modes, and related scenarios.
Bayesian Error Based Sequences of Mutual Information Bounds
Venue: arXiv cs.IT 2014
Year: 2014

The inverse relation between mutual information (MI) and Bayesian error is sharpened by deriving finite sequences of upper and lower bounds on MI in terms of the minimum probability of error (MPE) and related Bayesian quantities. The well known Fano upper bound and Feder-Merhav lower bound on equivocation are tightened by including a succession of posterior probabilities starting at the largest, which directly controls the MPE, and proceeding to successively lower ones. A number of other interesting results are also derived, including a sequence of upper bounds on the MPE in terms of a previously introduced sequence of generalized posterior distributions. The tightness of the various bounds is illustrated for a simple application of joint spatial localization and spectral typing of a point source.
A Queueing Network Approach to the Analysis and Control of Mobility-On-Demand Systems
Venue: arXiv cs.PF 2014
Year: 2014

This paper presents a queueing network approach to the analysis and control of mobility-on-demand (MoD) systems for urban personal transportation. A MoD system consists of a fleet of vehicles providing one-way car sharing service and a team of drivers to rebalance such vehicles. The drivers then rebalance themselves by driving select customers similar to a taxi service. We model the MoD system as two coupled closed Jackson networks with passenger loss. We show that the system can be approximately balanced by solving two decoupled linear programs and exactly balanced through nonlinear optimization. The rebalancing techniques are applied to a system sizing example using taxi data in three neighborhoods of Manhattan, which suggests that the optimal vehicle-to-driver ratio in a MoD system is between 3 and 5. Lastly, we formulate a real-time closed-loop rebalancing policy for drivers and demonstrate its stability (in terms of customer wait times) for typical system loads.
Recent Progress in Image Deblurring
Venue: arXiv cs.CV 2014
Year: 2014

This paper comprehensively reviews the recent development of image deblurring, including non-blind/blind, spatially invariant/variant deblurring techniques. Indeed, these techniques share the same objective of inferring a latent sharp image from one or several corresponding blurry images, while the blind deblurring techniques are also required to derive an accurate blur kernel. Considering the critical role of image restoration in modern imaging systems to provide high-quality images under complex environments such as motion, undesirable lighting conditions, and imperfect system components, image deblurring has attracted growing attention in recent years. From the viewpoint of how to handle the ill-posedness which is a crucial issue in deblurring tasks, existing methods can be grouped into five categories: Bayesian inference framework, variational methods, sparse representation-based methods, homography-based modeling, and region-based methods. In spite of achieving a certain level of development, image deblurring, especially the blind case, is limited in its success by complex application conditions which make the blur kernel hard to obtain and be spatially variant. We provide a holistic understanding and deep insight into image deblurring in this review. An analysis of the empirical evidence for representative methods, practical issues, as well as a discussion of promising future directions are also presented.
Sign-Compute-Resolve for Random Access
Venue: arXiv cs.IT 2014
Year: 2014

We present an approach to random access that is based on three elements: physical-layer network coding, signature codes and tree splitting. Upon occurrence of a collision, physical-layer network coding enables the receiver to decode the sum of the information that was transmitted by the individual users. For each user this information consists of the data that the user wants to communicate as well as the user's signature. As long as no more than $K$ users collide, their identities can be recovered from the sum of their signatures. A splitting protocol is used to deal with the case that more than $K$ users collide. We measure the performance of the proposed method in terms of user resolution rate as well as overall throughput of the system. The results show that our approach significantly increases the performance of the system even compared to coded random access, where collisions are not wasted, but are reused in successive interference cancellation.
Do More Dropouts in Pool5 Feature Maps for Better Object Detection
Venue: arXiv cs.CV 2014
Year: 2014

Deep Convolutional Neural Networks (CNNs) have gained great success in image classification and object detection. In these fields, the outputs of all layers of CNNs are usually considered as a high dimensional feature vector extracted from an input image and the correspondence between finer level feature vectors and concepts that the input image contains is all-important. However, fewer studies focus on this deserving issue. On considering the correspondence, we propose a novel approach which generates an edited version for each original CNN feature vector by applying the maximum entropy principle to abandon particular vectors. These selected vectors correspond to the unfriendly concepts in each image category. The classifier trained from merged feature sets can significantly improve model generalization of individual categories when training data is limited. The experimental results for classification-based object detection on canonical datasets including VOC 2007 (60.1%), 2010 (56.4%) and 2012 (56.3%) show obvious improvement in mean average precision (mAP) with simple linear support vector machines.
Meta-Modeling Semantics of UML
Venue: arXiv cs.SE 2014
Year: 2014

The Unified Modelling Language is emerging as a de-facto standard for modelling object-oriented systems. However, the semantics document that a part of the standard definition primarily provides a description of the language's syntax and well-formedness rules. The meaning of the language, which is mainly described in English, is too informal and unstructured to provide a foundation for developing formal analysis and development techniques. This paper outlines a formalisation strategy for making precise the core semantics of UML. This is achieved by strengthening the denotational semantics of the existing UML metamodel. To illustrate the approach, the semantics of generalization/specialization are made precise.
BMW-ROOM An Object-Oriented Method for ASCET
Venue: arXiv cs.SE 2014
Year: 2014

This paper presents an object-oriented method customized for a tool-assisted development of car software components. Tough market conditions motivate smart software development. ASCET SD is a tool to generate target code from graphic specifications, avoiding costly programming in C. But ASCET lacks guidelines on what to do, how to do it, in what order, like a fully equipped kitchen without a cooking book. Plans to employ the tool for BMW vehicle software sparked off demand for an adequate, object-oriented real-time methodology. We show how to scan the methodology market in order to adopt an already existing method for this purpose. The result of the adaptation of a chosen method to ASCET SD is a pragmatic version of ROOM, which we call BROOM. We present a modeling guidebook that includes process recommendations not only for the automotive sector, but for real-time software development in general. The method suggests to produce early prototypes that are validated and refined to completion. BROOM offers phase-independent, harmonic guidelines. Product requirements, in form of scenarios, are transformed through several activities into operational models. BROOM takes advantage of ASCET's rich experimentation- and code generation features. These allow to validate emerging models on button press. The factual development of a simplified heating/cooling system at BMW serves as a running example throughout the paper.
Knowledge discovery via multidimensional science maps: the case of the Species Problem
Venue: arXiv cs.DL 2014
Year: 2014

Science mapping (SM), the study of the organization and development of science and technology, is a rapidly developing field within information science. The volume of available data allows this methodology to empirically address such issues as the historical development of topics, discourses, fields or the entire science system. Based on the pool of related methods, we are proposing an integration of various maps to obtain a novel kind of science map we call multidimensional. The basic idea behind is to combine the most informative relations available from various maps based on different bibliometric indicators, in order to produce a rich structrue for the study of knowledge dynamics, with special emphasis on causal-historical connections. As a proof of concept, we deploy the proposed framework in an extensive case study on a historical topic from the life sciences, namely, the debate on the species concept in biosystematics.
Symmetric Submodular Clustering with Actionable Constraint
Venue: arXiv cs.DS 2014
Year: 2014

Clustering with submodular functions has been of interest over the last few years. Symmetric submodular functions are of particular interest as minimizing them is significantly more efficient and they include many commonly used functions in practice viz. graph cuts, mutual information. In this paper, we propose a novel constraint to make clustering actionable which is motivated by applications across multiple domains, and pose the problem of performing symmetric submodular clustering subject to this constraint. We see that obtaining a $k$ partition with approximation guarantees is a non-trivial task requiring further work.
Shortest Paths in Nearly Conservative Digraphs
Venue: arXiv cs.DS 2014
Year: 2014

We introduce the following notion: a digraph $D=(V,A)$ with arc weights $c: A\rightarrow \R$ is called nearly conservative if every negative cycle consists of two arcs. Computing shortest paths in nearly conservative digraphs is NP-hard, and even deciding whether a digraph is nearly conservative is coNP-complete. We show that the "All Pairs Shortest Path" problem is fixed parameter tractable with various parameters for nearly conservative digraphs. The results also apply for the special case of conservative mixed graphs.
Adding Geographical Embedding to AS Topology Generation
Venue: arXiv cs.NI 2014
Year: 2014

To study large-scale effects on the Internet various mod- els have been introduced to generate Internet-like autono- mous system (AS) topologies. The models for large-scale AS topologies have been focused on replicating structural graph properties. One of the most promising model is the Positive Feedback Model model (PFP). These models how- ever lack the ability to generate routing path and realistic latency. We present a model to enrich the AS peering graph with peering points. Our new model allows to calculate path for the connections between end hosts and to infer the latency from these paths. We introduce a new notion for the genera- tion of AS topologies: the compactness of an AS. We introduce an algorithm based on the PFP algorithm which generates instances for our model. Verifying the gen- erated model instances shows that the resulting latencies as well as the geographic properties match measured data sets.