OpenRaiser/Intern-Atlas huggingface dataset:
Interactive Visual Exploration of Topic Models using Graphs
Venue: arXiv cs.IR 2014
Year: 2014

Probabilistic topic modeling is a popular and powerful family of tools for uncovering thematic structure in large sets of unstructured text documents. While much attention has been directed towards the modeling algorithms and their various extensions, comparatively few studies have concerned how to present or visualize topic models in meaningful ways. In this paper, we present a novel design that uses graphs to visually communicate topic structure and meaning. By connecting topic nodes via descriptive keyterms, the graph representation reveals topic similarities, topic meaning and shared, ambiguous keyterms. At the same time, the graph can be used for information retrieval purposes, to find documents by topic or topic subsets. To exemplify the utility of the design, we illustrate its use for organizing and exploring corpora of financial patents.
A Formal Methods Approach to Pattern Synthesis in Reaction Diffusion Systems
Venue: arXiv cs.AI 2014
Year: 2014

We propose a technique to detect and generate patterns in a network of locally interacting dynamical systems. Central to our approach is a novel spatial superposition logic, whose semantics is defined over the quad-tree of a partitioned image. We show that formulas in this logic can be efficiently learned from positive and negative examples of several types of patterns. We also demonstrate that pattern detection, which is implemented as a model checking algorithm, performs very well for test data sets different from the learning sets. We define a quantitative semantics for the logic and integrate the model checking algorithm with particle swarm optimization in a computational framework for synthesis of parameters leading to desired patterns in reaction-diffusion systems.
Elastic Business Process Management: State of the Art and Open Challenges for BPM in the Cloud
Venue: arXiv cs.DC 2014
Year: 2014

With the advent of cloud computing, organizations are nowadays able to react rapidly to changing demands for computational resources. Not only individual applications can be hosted on virtual cloud infrastructures, but also complete business processes. This allows the realization of so-called elastic processes, i.e., processes which are carried out using elastic cloud resources. Despite the manifold benefits of elastic processes, there is still a lack of solutions supporting them. In this paper, we identify the state of the art of elastic Business Process Management with a focus on infrastructural challenges. We conceptualize an architecture for an elastic Business Process Management System and discuss existing work on scheduling, resource allocation, monitoring, decentralized coordination, and state management for elastic processes. Furthermore, we present two representative elastic Business Process Management Systems which are intended to counter these challenges. Based on our findings, we identify open issues and outline possible research directions for the realization of elastic processes and elastic Business Process Management.
Active Dictionary Learning in Sparse Representation Based Classification
Venue: arXiv cs.CV 2014
Year: 2014

Sparse representation, which uses dictionary atoms to reconstruct input vectors, has been studied intensively in recent years. A proper dictionary is a key for the success of sparse representation. In this paper, an active dictionary learning (ADL) method is introduced, in which classification error and reconstruction error are considered as the active learning criteria in selection of the atoms for dictionary construction. The learned dictionaries are caculated in sparse representation based classification (SRC). The classification accuracy and reconstruction error are used to evaluate the proposed dictionary learning method. The performance of the proposed dictionary learning method is compared with other methods, including unsupervised dictionary learning and whole-training-data dictionary. The experimental results based on the UCI data sets and face data set demonstrate the efficiency of the proposed method.
Multiband Spectrum Access: Great Promises for Future Cognitive Radio Networks
Venue: arXiv cs.IT 2014
Year: 2014

Cognitive radio has been widely considered as one of the prominent solutions to tackle the spectrum scarcity. While the majority of existing research has focused on single-band cognitive radio, multiband cognitive radio represents great promises towards implementing efficient cognitive networks compared to single-based networks. Multiband cognitive radio networks (MB-CRNs) are expected to significantly enhance the network's throughput and provide better channel maintenance by reducing handoff frequency. Nevertheless, the wideband front-end and the multiband spectrum access impose a number of challenges yet to overcome. This paper provides an in-depth analysis on the recent advancements in multiband spectrum sensing techniques, their limitations, and possible future directions to improve them. We study cooperative communications for MB-CRNs to tackle a fundamental limit on diversity and sampling. We also investigate several limits and tradeoffs of various design parameters for MB-CRNs. In addition, we explore the key MB-CRNs performance metrics that differ from the conventional metrics used for single-band based networks.
Robust Multi-Branch Tomlinson-Harashima Precoding in Cooperative MIMO Relay Systems
Venue: arXiv cs.IT 2014
Year: 2014

This paper proposes the design of robust transceivers with Tomlinson-Harashima precoding (THP) for multiple-input multiple-output (MIMO) relay systems with amplify-and-forward (AF) protocols based on a multi-branch (MB) strategy. The MB strategy employs successive interference cancellation (SIC) on several parallel branches which are equipped with different ordering patterns so that each branch produces transmit signals by exploiting a certain ordering pattern. For each parallel branch, the proposed robust nonlinear transceiver design consists of THP at the source along with a linear precoder at the relay and a linear minimum-mean-squared-error (MMSE) receiver at the destination. By taking the channel uncertainties into account, the source and relay precoders are jointly optimised to minimise the mean-squared-error (MSE). We then employ a diagonalization method along with some attributes of matrix-monotone functions to convert the optimization problem with matrix variables into an optimization problem with scalar variables. We resort to an iterative method to obtain the solution for the relay and the source precoders via Karush-Kuhn-Tucker (KKT) conditions. An appropriate selection rule is developed to choose the nonlinear transceiver corresponding to the best branch for data transmission. Simulation results demonstrate that the proposed MB-THP scheme is capable of alleviating the effects of channel state information (CSI) errors and improving the robustness of the system.
Structure and complexity of ex post efficient random assignments
Venue: arXiv cs.GT 2014
Year: 2014

In the random assignment problem, objects are randomly assigned to agents keeping in view the agents' preferences over objects. A random assignment specifies the probability of an agent getting an object. We examine the structural and computational aspects of ex post efficiency of random assignments. We first show that whereas an ex post efficient assignment can be computed easily, checking whether a given random assignment is ex post efficient is NP-complete. Hence implementing a given random assignment via deterministic Pareto optimal assignments is NP-hard. We then formalize another concept of efficiency called robust ex post efficiency that is weaker than stochastic dominance efficiency but stronger than ex post efficiency. We present a characterization of robust ex post efficiency and show that it can be tested in polynomial time if there are a constant number of agent types. It is shown that the well-known random serial dictatorship rule is not robust ex post efficient. Finally, we show that whereas robust ex post efficiency depends solely on which entries of the assignment matrix are zero/non-zero, ex post efficiency of an assignment depends on the actual values.
Identification of Influential Scientists vs. Mass Producers by the Perfectionism Index
Venue: arXiv cs.DL 2014
Year: 2014

The concept of h-index has been proposed to easily assess a researcher's performance with a single number. However, by using only this number, we lose significant information about the distribution of citations per article in an author's publication list. In this article, we study an author's citation curve and we define two new areas related to this curve. We call these "penalty areas", since the greater they are, the more an author's performance is penalized. We exploit these areas to establish new indices, namely PI and XPI, aiming at categorizing researchers in two distinct categories: "influentials" and "mass producers"; the former category produces articles which are (almost all) with high impact, and the latter category produces a lot of articles with moderate or no impact at all. Using data from Microsoft Academic Service, we evaluate the merits mainly of PI as a useful tool for scientometric studies. We establish its effectiveness into separating the scientists into influentials and mass producers; we demonstrate its robustness against self-citations, and its uncorrelation to traditional indices. Finally, we apply PI to rank prominent scientists in the areas of databases, networks and multimedia, exhibiting the strength of the index in fulfilling its design goal.
Computing the $p$-adic Canonical Quadratic Form in Polynomial Time
Venue: arXiv cs.DS 2014
Year: 2014

An $n$-ary integral quadratic form is a formal expression $Q(x_1,..,x_n)=\sum_{1\leq i,j\leq n}a_{ij}x_ix_j$ in $n$-variables $x_1,...,x_n$, where $a_{ij}=a_{ji} \in \mathbb{Z}$. We present a randomized polynomial time algorithm that given a quadratic form $Q(x_1,...,x_n)$, a prime $p$, and a positive integer $k$ outputs a $\mathtt{U} \in \text{GL}_n(\mathbb{Z}/p^k\mathbb{Z})$ such that $\mathtt{U}$ transforms $Q$ to its $p$-adic canonical form.
Roaming charges for customers of cellular-wireless entrant and incumbent providers
Venue: arXiv cs.NI 2014
Year: 2014

We consider a simple two-player game involving a large incumbent and small entrant into a cellular wireless access provider marketplace. The entrant's customers must pay roaming charges. We assume that the roaming charges are regulated, because if they are dictated by the incumbent then they could be set so high so as to be a barrier to entry in the marketplace. The game is studied at its Nash equilibrium. A roaming charge is identified that is arguably fair in the sense that revenues for the access providers are proportionate to their infrastructure costs.
Communication-aware algorithms for target tracking in wireless sensor networks
Venue: arXiv cs.NI 2014
Year: 2014

This paper introduces algorithms for target tracking in wireless sensor networks (WSNs) that enable reduction of data communication cost. The objective of the considered problem is to control movement of a mobile sink which has to reach a moving target in the shortest possible time. Consumption of the WSN energy resources is reduced by transferring only necessary data readings (target positions) to the mobile sink. Simulations were performed to evaluate the proposed algorithms against existing methods. The experimental results confirm that the introduced tracking algorithms allow the data communication cost to be considerably reduced without significant increase in the amount of time that the sink needs to catch the target.
A non-linear learning & classification algorithm that achieves full training accuracy with stellar classification accuracy
Venue: arXiv cs.CV 2014
Year: 2014

A fast Non-linear and non-iterative learning and classification algorithm is synthesized and validated. This algorithm named the "Reverse Ripple Effect(R.R.E)", achieves 100% learning accuracy but is computationally expensive upon classification. The R.R.E is a (deterministic) algorithm that super imposes Gaussian weighted functions on training points. In this work, the R.R.E algorithm is compared against known learning and classification techniques/algorithms such as: the Perceptron Criterion algorithm, Linear Support Vector machines, the Linear Fisher Discriminant and a simple Neural Network. The classification accuracy of the R.R.E algorithm is evaluated using simulations conducted in MATLAB. The R.R.E algorithm's behaviour is analyzed under linearly and non-linearly separable data sets. For the comparison with the Neural Network, the classical XOR problem is considered.
Quantitative Computation Tree Logic Model Checking Based on Generalized Possibility Measures
Venue: arXiv cs.LO 2014
Year: 2014

We study generalized possibilistic computation tree logic model checking in this paper, which is an extension of possibilistic computation logic model checking introduced by Y.Li, Y.Li and Z.Ma (2014). The system is modeled by generalized possibilistic Kripke structures (GPKS, in short), and the verifying property is specified by a generalized possibilistic computation tree logic (GPoCTL, in short) formula. Based on generalized possibility measures and generalized necessity measures, the method of generalized possibilistic computation tree logic model checking is discussed, and the corresponding algorithm and its complexity are shown in detail. Furthermore, the comparison between PoCTL introduced in (2013) and GPoCTL is given. Finally, a thermostat example is given to illustrate the GPoCTL model-checking method.
Caroline: An Autonomously Driving Vehicle for Urban Environments
Venue: arXiv cs.RO 2014
Year: 2014

The 2007 DARPA Urban Challenge afforded the golden opportunity for the Technische Universität Braunschweig to demonstrate its abilities to develop an autonomously driving vehicle to compete with the world's best competitors. After several stages of qualification, our team CarOLO qualified early for the DARPA Urban Challenge Final Event and was among only eleven teams from initially 89 competitors to compete in the final. We had the ability to work together in a large group of experts, each contributing his expertise in his discipline, and significant organisational, financial and technical support by local sponsors who helped us to become the best non-US team. In this report, we describe the 2007 DARPA Urban Challenge, our contribution "Caroline", the technology and algorithms along with her performance in the DARPA Urban Challenge Final Event on November 3, 2007.
Executable Modeling with UML. A Vision or a Nightmare?
Venue: arXiv cs.SE 2014
Year: 2014

Extreme Programming is the most prominent new, light-weight (or agile) methods, defined to contrast the current heavy-weight and partially overloaded object-oriented methods. It focuses on the core issues of software technology. One of its principles is not to rely on diagrams to document a system. In this paper, we examine what properties a modeling language like UML must have in order to support the Extreme Programming approach effectively. In particular, we discuss how such a diagrammatic programming language must look like to replace a textual programming language and what benefits and problems such an approach may bring.
A Security Architecture for Mobile Wireless Sensor Networks
Venue: arXiv cs.CR 2014
Year: 2014

Wireless sensor networks increasingly become viable solutions to many challenging problems and will successively be deployed in many areas in the future. However, deploying new technology without security in mind has often proved to be unreasonably dangerous. We propose a security architecture for self-organizing mobile wireless sensor networks that prevents many attacks these networks are exposed to. Furthermore, it limits the security impact of some attacks that cannot be prevented. We analyse our security architecure and show that it provides the desired security aspects while still being a lightweight solution and thus being applicable for self-organizing mobile wireless sensor networks.
Towards Enabling Architectural Refactorings through Source Code Annotations
Venue: arXiv cs.SE 2014
Year: 2014

It is well known that software needs to change to meet new requirements. The synchronization of software architecture models and implementation is of high importance to keep the architecture documents useful and the software evolution process manageable. In this paper we achieve this synchronization by a two-step process. First, we augment the source code with architectural information. Second, this "lightweight architectural model" can be checked more easily against the full architectural description. Based on this approach refactorings on either side (code or architecture) are detected automatically and conformance checks become possible.
UML 2 Semantics Symposium: Formal Semantics for UML
Venue: arXiv cs.SE 2014
Year: 2014

The purpose of this symposium, held in conjunction with MoDELS 2006, was to present the current state of research of the UML 2 Semantics Project. Equally important to receiving feedback from an audience of experts was the opportunity to invite researchers in the field to discuss their own work related to a formal semantics for the Unified Modeling Language. This symposium is a follow-on to our first workshop, held in conjunction with ECMDA 2005.
Efficient Editor Generation for Compositional DSLs in Eclipse
Venue: arXiv cs.SE 2014
Year: 2014

When a domain specific language (DSL) shall be commonly used, it is important for the development team to have a comfortable editor well integrated in the project's development environment. As DSL are rather often subject to changes, efficient development and evolvement of a comfortable editor is an important success criterion for the acceptance of domain specific languages. In this paper we demonstrate how this issue is addressed in the MontiCore DSL development framework. Basically an extension of the MontiCore DSL definition language can be used to efficiently generate DSL editors for Eclipse. The generation tool also supports the compositional language definition features of MontiCore and allows therefore the reuse of existing language and editor definitions.
Evolving and Implanting Web-based E-Government Systems in Universities
Venue: arXiv cs.CY 2014
Year: 2014

The Bologna Process has triggered a major restructuring of the current university diploma into a bachelor/master system. As one effect, the administration effort for the new system has increased dramatically. As a second effect, students need and demand a much better information policy, given the new possibilities of the internet. Both to increase efficiency of the university's administration and to provide students as well as lecturers with modern e government services, it is inevitable to evolve the current IT-infrastructure of a university into a modern web-based landscape of systems that support business processes on campus. In this paper, we describe the approach taken at the Braunschweig University of Technology to evolve the existing landscape of legacy systems by adding bridges between previously unrelated parts, adding and customizing unused modules of existing software to bring information and services online and to develop new software, where old modules could not serve the necessary purposes. Most of all, both implementation of the results in university's business processes and the resulting quick feedback and wishes for feature enhancement are seen as part of the software development processes and discussed in this paper.
Heterogeneous Multi core processors for improving the efficiency of Market basket analysis algorithm in data mining
Venue: arXiv cs.DC 2014
Year: 2014

Heterogeneous multi core processors can offer diverse computing capabilities. The efficiency of Market Basket Analysis Algorithm can be improved with heterogeneous multi core processors. Market basket analysis algorithm utilises apriori algorithm and is one of the popular data mining algorithms which can utilise Map/Reduce framework to perform analysis. The algorithm generates association rules based on transactional data and Map/Reduce motivates to redesign and convert the existing sequential algorithms for efficiency. Hadoop is the parallel programming platform built on Hadoop Distributed File Systems(HDFS) for Map/Reduce computation that process data as (key, value) pairs. In Hadoop map/reduce, the sequential jobs are parallelised and the Job Tracker assigns parallel tasks to the Task Tracker. Based on single threaded or multithreaded parallel tasks in the task tracker, execution is carried out in the appropriate cores. For this, a new scheduler called MB Scheduler can be developed. Switching between the cores can be made static or dynamic. The use of heterogeneous multi core processors optimizes processing capabilities and power requirements for a processor and improves the performance of the system.
Model Checking Software Programs with First Order Logic Specifications using AIG Solvers
Venue: arXiv cs.SE 2014
Year: 2014

Static verification techniques leverage Boolean formula satisfiability solvers such as SAT and SMT solvers that operate on conjunctive normal form and first order logic formulae, respectively, to validate programs. They force bounds on variable ranges and execution time and translate the program and its specifications into a Boolean formula. They are limited to programs of relatively low complexity for the following reasons. (1) A small increase in the bounds can cause a large increase in the size of the translated formula. (2) Boolean satisfiability solvers are restricted to using optimizations that apply at the level of the formula. Finally, (3) the Boolean formulae often need to be regenerated with higher bounds to ensure the correctness of the translation. We present a method that uses sequential circuits, Boolean formulae with memory elements and hierarchical structure, and sequential circuit synthesis and verification frameworks to validate programs. (1) Sequential circuits are much more succinct than Boolean formulae with no memory elements and preserve the high-level structure of the program. (2) Encoding the problem as a sequential circuit enables the use of a number of powerful automated analysis techniques that have no counterparts for other Boolean formulae. Our method takes an imperative program with a first order logic specification consisting of a precondition and a postcondition pair, and a bound on the program variable ranges, and produces a sequential circuit with a designated output that is true when the program violates the specification.
UML-F: A Modeling Language for Object-Oriented Frameworks
Venue: arXiv cs.SE 2014
Year: 2014

The paper presents the essential features of a new member of the UML language family that supports working with object-oriented frameworks. This UML extension, called UML-F, allows the explicit representation of framework variation points. The paper discusses some of the relevant aspects of UML-F, which is based on standard UML extension mechanisms. A case study shows how it can be used to assist framework development. A discussion of additional tools for automating framework implementation and instantiation rounds out the paper.
A Note on Semantics (with an Emphasis on UML)
Venue: arXiv cs.SE 2014
Year: 2014

This note clarifies the concept of syntax and semantics and their relationships. Today, a lot of confusion arises from the fact that the word "semantics" is used in different meanings. We discuss a general approach at defining semantics that is feasible for both textual and diagrammatic notations and discuss this approach using an example formalization. The formalization of hierarchical Mealy automata and their semantics definition using input/output behaviors allows us to define a specification, as well as an implementation semantics. Finally, a classification of different approaches that fit in this framework is given. This classification may also serve as guideline when defining a semantics for a new language.