Using Custom Mininet Topology Configuring L2-Switch in Opendaylight

Software Defined Networking is a new way of making traditional hardware based network management into software based controlling. To do this, require a emulator like Mininet, a freely available open source network simulator software for creating custom topologies of our wish in virtual environment and it also permits to create OpenFlow switches, hosts and an SDN controller in a virtual network all with a simple command on a Linux Kernal.and It is a better approach to start practicing about SDN and Open-Flow as well as test SDN controllers like OpenDaylight. In this paper, by creating custom topology in python script and use of OpenDaylight controller environment for controlling flows in openflow enabled switches and then configuring L2-Switch features and observe the out comes

Entanglement of Exact Excited States of AKLT Models: Exact Results, Many-Body Scars and the Violation of Strong ETH

We obtain multiple exact results on the entanglement of the exact excited states of non-integrable models we introduced in arXiv:1708.05021. We first discuss a general formalism to analytically compute the entanglement spectra of exact excited states using Matrix Product States and Matrix Product Operators and illustrate the method by reproducing a general result on single-mode excitations. We then apply this technique to analytically obtain the entanglement spectra of the infinite tower of states of the spin-$S$ AKLT models in the zero and finite energy density limits. We show that in the zero density limit, the entanglement spectra of the tower of states are multiple shifted copies of the ground state entanglement spectrum in the thermodynamic limit. We show that such a resemblance is destroyed at any non-zero energy density. Furthermore, the entanglement entropy $\mathcal{S}$ of the states of the tower that are in the bulk of the spectrum is sub-thermal $\mathcal{S} \propto \log L$, as opposed to a volume-law $\mathcal{S} \propto L$, thus indicating a violation of the strong Eigenstate Thermalization Hypothesis (ETH). These states are examples of what are now called many-body scars. Finally, we analytically study the finite-size effects and symmetry-protected degeneracies in the entanglement spectra of the excited states, extending the existing theory.Comment: 44 pages, 6 figures v2: References adde

Evolutionary testing of autonomous software agents

A system built in terms of autonomous software agents may require even greater correctness assurance than one that is merely reacting to the immediate control of its users. Agents make substantial decisions for themselves, so thorough testing is an important consideration. However, autonomy also makes testing harder; by their nature, autonomous agents may react in different ways to the same inputs over time, because, for instance they have changeable goals and knowledge. For this reason, we argue that testing of autonomous agents requires a procedure that caters for a wide range of test case contexts, and that can search for the most demanding of these test cases, even when they are not apparent to the agents’ developers. In this paper, we address this problem, introducing and evaluating an approach to testing autonomous agents that uses evolutionary optimisation to generate demanding test cases. We propose a methodology to derive objective (fitness) functions that drive evolutionary algorithms, and evaluate the overall approach with two simulated autonomous agents. The obtained results show that our approach is effective in finding good test cases automatically

A Case Study of Test-Driven Development

Magistritöö eesmärk on analüüsida idufirmade näitel test-driven development (TDD) tarkvaraarendusprotsessides rakendamise tugevusi ja nõrkusi. Magistritöö kirjeldab uurimust kolmesetapis: esimene etapp keskendub varajases staadiumis idufirmade uurimisele, kus on jubaTDD rakendatud ning kus firma ülesandeks on rakendada tarkvara teenuse (ingl. k. SaaS)toodet oma klientidele (firma A). Selle etapi eesmärgiks on analüüsida hetkel olemasolevattarkvaraarenduse metoodikat ja millist rolli täidab TDD kogu protsessis. Teine etappkeskendub hetkel kasutatavate TDD praktikate tuvastamisele ettevõttes, mis on edukaltjuurutanud nimetatud praktika oma tarkvaraarendusse (firma B). See etapp koosnebpõhjalikust TDD praktika analüüsist firmas B - kuidas võeti TDD esmakordselt kasutusele,juurutamisel esinevad väljakutsed, TDD kasutuselevõtmise põhjused ning idufirma nägemusTDD tuleviku suhtes. Kolmas ehk viimane etapp keskendub andmete kogumisele teisteltettevõtetelt, mis kasutavad TDD-d ning analüüs, kuidas saaks antud uuringust saadudandmepõhiseid teadmisi kasutada otsuse langetamiseks firma A jaoks, arvestades TDDeeliseid ja puudusi.The purpose of this study is to analyse the benefits and/or drawbacks regarding theimplementation of Test Driven Development (TDD) as part of the software developmentlifecycle of startup companies. This study was conducted in three phases: The first phasefocused on a study of the current TDD implementations in an early stage startup companyassigned the task of delivering Software as a Service(SaaS) product to their clients (CompanyA). The main purpose of this stage will be to analyse the current existing softwaredevelopment methodology and what role (if any) TDD plays in the entire process. Thesecond phase revolved around identifying the current existing practices of TDD in a companythat has successfully embedded the practice into their software development lifecycle(Company B). This phase involved an in depth analysis of the TDD practice in Company B:how it was first introduced, the challenges faced during the initial stages of implementation,reasons for its adoption as well as their views on the future of TDD. The third and finalphase focused on gathering data from other companies that practice TDD and how theknowledge acquired from this study can be used to make a data driven decision regarding thebenefits/drawback of TDD for company A

From Smalltalk to Silicon: Towards a methodology to turn Smalltalk code into FPGA

International audienceDue to their ability to combine high performances along with flexibility, FPGAs (Field Programmable Gate Array) are used in robotic applications nowadays, especially in case of realtime applications. The FPGA circuits are often designed and configured using the Hardware Description Languages (HDLs) like VHDL or Verilog. However, although these languages provide abstractions up to the functionality level, they lack many features of todays modern languages that make them unsuited for high-level models and systems. In this paper, we present an overview of a methodology that uses a Dynamic Reflective Language, such as Smalltalk, for high level hardware/software co-design on FPGAs

Practical domain-specific debuggers using the Moldable Debugger framework

International audienceUnderstanding the run-time behavior of software systems can be a challenging activity. Debuggers are an essential category of tools used for this purpose as they give developers direct access to the running systems. Nevertheless, traditional debuggers rely on generic mechanisms to introspect and interact with the running systems, while developers reason about and formulate domain-specific questions using concepts and abstractions from their application domains. This mismatch creates an abstraction gap between the debugging needs and the debugging support leading to an inefficient and error-prone debugging effort, as developers need to recover concrete domain concepts using generic mechanisms. To reduce this gap, and increase the efficiency of the debugging process, we propose a framework for developing domain-specific debuggers, called the Moldable Debugger, that enables debugging at the level of the application domain. The Moldable Debugger is adapted to a domain by creating and combining domain-specific debugging operations with domain-specific debugging views, and adapts itself to a domain by selecting, at run time, appropriate debugging operations and views. To ensure the proposed model has practical applicability (i.e., can be used in practice to build real debuggers), we discuss, from both a performance and usability point of view, three implementation strategies. We further motivate the need for domain-specific debugging, identify a set of key requirements and show how our approach improves debugging by adapting the debugger to several domains

Software engineering principles to improve quality and performance of R software

Today’s computational researchers are expected to be highly proficient in using software to solve a wide range of problems ranging from processing large datasets to developing personalized treatment strategies from a growing range of options. Researchers are well versed in their own field, but may lack formal training and appropriate mentorship in software engineering principles. Two major themes not covered in most university coursework nor current literature are software testing and software optimization. Through a survey of all currently available Comprehensive R Archive Network packages, we show that reproducible and replicable software tests are frequently not available and that many packages do not appear to employ software performance and optimization tools and techniques. Through use of examples from an existing R package, we demonstrate powerful testing and optimization techniques that can improve the quality of any researcher’s software

Competitive binding of E3 ligases TRIM26 and WWP2 controls SOX2 in glioblastoma

The pluripotency transcription factor SOX2 is essential for the maintenance of glioblastoma stem cells (GSC), which are thought to underlie tumor growth, treatment resistance, and recurrence. To understand how SOX2 is regulated in GSCs, we utilized a proteomic approach and identified the E3 ubiquitin ligase TRIM26 as a direct SOX2-interacting protein. Unexpectedly, we found TRIM26 depletion decreased SOX2 protein levels and increased SOX2 polyubiquitination in patient-derived GSCs, suggesting TRIM26 promotes SOX2 protein stability. Accordingly, TRIM26 knockdown disrupted the SOX2 gene network and inhibited both self-renewal capacity as well as in vivo tumorigenicity in multiple GSC lines. Mechanistically, we found TRIM26, via its C-terminal PRYSPRY domain, but independent of its RING domain, stabilizes SOX2 protein by directly inhibiting the interaction of SOX2 with WWP2, which we identify as a bona fide SOX2 E3 ligase in GSCs. Our work identifies E3 ligase competition as a critical mechanism of SOX2 regulation, with functional consequences for GSC identity and maintenance