scholarly journals Control flow based cost analysis for P4

2020 ◽  
Vol 11 (1) ◽  
pp. 70-79
Author(s):  
Dániel Lukács ◽  
Gergely Pongrácz ◽  
Máté Tejfel

AbstractThe networking industry is currently undergoing a steady trend of softwarization. Yet, network engineers suffer from the lack of software development tools that support programming of new protocols. We are creating a cost analysis tool for the P4 programming language, that automatically verifies whether the developed program meets soft deadline requirements imposed by the network. In this paper, we present an approach to estimate the average execution time of P4 program based on control flow graphs. Our approach takes into consideration that many of the parts of P4 are implementation-defined: required information can be added in through incremental refinement, while missing information is handled by falling back to less precise defaults. We illustrate application of this approach to a P4 protocol in two case studies: we use it to examine the effect of a compiler optimization in the deparse stage, and to show how it enables cost modelling complex lookup table implementations. Finally, we assess future research tasks to be completed before the tool is ready for real-world usage.

2020 ◽  
pp. 251512742097966
Author(s):  
Birgitte Wraae ◽  
Candida Brush ◽  
Shahrokh Nikou

Significant research explores effectiveness of entrepreneurial curriculum, teaching innovations and programs, but less often studied is the role of entrepreneurship educators. The way that the educator sees his or her role relative to the students is of critical importance because this directly influences pedagogy choices, expectations for students and learning outcomes, as well as job satisfaction. While recent studies propose typologies characterizing pedagogical approaches of educators, few of these are based on the data from entrepreneurship educators. Framed within role identity theory, we conducted 13 in–depth interviews to examine how entrepreneurship educators perceive their role. Using the qualitative data analysis tool (NVivo), we analyzed how the relationship between their perceptions of their role and core value orientation is connected to teaching approaches. Results show that these educators view their roles as teacher-focused, network-focused, or student-focused and that these perspectives are associated with different perceptions of students’ role and learning objectives. Further, we find different levels of emphasis on roles and that personal core values are differentially linked to these roles. Implications and future research directions are discussed.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gema Ramírez-Guerrero ◽  
Javier García-Onetti ◽  
Juan Adolfo Chica-Ruiz ◽  
Manuel Arcíla-Garrido

Purpose This paper attempts to fill the gap that exists in research regarding 20th-century heritage and its social appreciation. The purpose of this paper is to explore different ways of evaluating the heritage value and tourism potential and to propose an innovative model validated in the Zarzuela Hippodrome as an example of cultural asset from 20th century with important economic, social, cultural, aesthetic and architectural aspects. Design/methodology/approach This study opted for an interpretation of heritage from an ecosystem, integrating and global paradigm, understanding the asset as a set of resources that interact with each other, generating a common and enriched tourist experience among all the elements that make it up. From this perspective, it is conceived that by modifying one of the elements, the whole (tourist) ecosystem will be equally influenced. On the other side, it was incorporated non-parametric techniques based on the implementation of surveys for the validation of the tool to the case study of the Zarzuela hippodrome. Findings The results suggest that the hippodrome's internal values have been evaluated very positively, while its external values are low. Through this study, the paper has identified several weaknesses that impede its functioning as a viable “tourist product.” The distance from the city center, the lack of available information and the scarce diffusion and tourism promotion are its main weaknesses. The proposed analysis tool reveals the importance of the active participation of visitors to evaluate cultural assets through the combination of aspects related to the conservation of cultural assets and, in turn, elements that encourage their commodification as tourist products, break down barriers between these two disciplines. Research limitations/implications The management tool proposed in this study can be used to underpin the creation of tourism experiences in cultural or heritage assets by diagnosing the current state of its tourist potential, quantifying its value in relation to the visitors’ perception and making visible those problematic aspects to develop actions to solve them. Although the present study is support for future research, as well as for improving the marketing of heritage in tourist settings, an in-depth analysis of the technical elements of heritage, as well as of its intervention (if applicable), will be necessary for the managers who want to use the tool. Social implications One of the most differentiating characteristics between the construction typology of 20th-century historical buildings is perhaps the scarcity of decorative ornamentation, with exposed concrete being the main surface coating. Many of these constructions have an important cultural and historical relevance, however, the social perception, as regards its consideration as architectural and artistic heritage seems to reflect discordant aspects. This study provides support as a decision-making tool to determine the existing valuation of a building and how to enhance it. Originality/value This study takes steps toward the creation of a model that supports decision-makers and owners of cultural assets through a measurement system that makes it possible to quantify and determine the current state of tourism use through the social evaluation of heritage criteria. It defines which are the elements that favor the resilience of the property or, on the contrary, which are those that undermine its enhancement.


1997 ◽  
Vol 2 (1) ◽  
pp. 133-152 ◽  
Author(s):  
Paul Rayson ◽  
Geoffrey N. Leech ◽  
Mary Hodges

In this article, we undertake selective quantitative analyses of the demographi-cally-sampled spoken English component of the British National Corpus (for brevity, referred to here as the ''Conversational Corpus"). This is a subcorpus of c. 4.5 million words, in which speakers and respondents (see I below) are identified by such factors as gender, age, social group, and geographical region. Using a corpus analysis tool developed at Lancaster, we undertake a comparison of the vocabulary of speakers, highlighting those differences which are marked by a very high X2 value of difference between different sectors of the corpus according to gender, age, and social group. A fourth variable, that of geographical region of the United Kingdom, is not investigated in this article, although it remains a promising subject for future research. (As background we also briefly examine differences between spoken and written material in the British National Corpus [BNC].) This study is illustrative of the potentiality of the Conversational Corpus for future corpus-based research on social differentiation in the use of language. There are evident limitations, including (a) the reliance on vocabulary frequency lists and (b) the simplicity of the transcription system employed for the spoken part of the BNC The conclusion of the article considers future advances in the research paradigm illustrated here.


2020 ◽  
Vol 23 (3) ◽  
pp. 473-493
Author(s):  
Nikita Andreevich Kataev ◽  
Alexander Andreevich Smirnov ◽  
Andrey Dmitrievich Zhukov

The use of pointers and indirect memory accesses in the program, as well as the complex control flow are some of the main weaknesses of the static analysis of programs. The program properties investigated by this analysis are too conservative to accurately describe program behavior and hence they prevent parallel execution of the program. The application of dynamic analysis allows us to expand the capabilities of semi-automatic parallelization. In the SAPFOR system (System FOR Automated Parallelization), a dynamic analysis tool has been implemented, based on on the instrumentation of the LLVM representation of an analyzed program, which allows the system to explore programs in both C and Fortran programming languages. The capabilities of the static analysis implemented in SAPFOR are used to reduce the overhead program execution, while maintaining the completeness of the analysis. The use of static analysis allows to reduce the number of analyzed memory accesses and to ignore scalar variables, which can be explored in a static way. The developed tool was tested on performance tests from the NAS Parallel Benchmarks package for C and Fortran languages. The implementation of dynamic analysis, in addition to traditional types of data dependencies (flow, anit, output), allows us to determine privitizable variables and a possibility of pipeline execution of loops. Together with the capabilities of DVM and OpenMP these greatly facilitates program parallelization and simplify insertion of the appropriate compiler directives.


Author(s):  
Rémi Géraud ◽  
Mirko Koscina ◽  
Paul Lenczner ◽  
David Naccache ◽  
David Saulpic
Keyword(s):  

Author(s):  
Bing Qiao ◽  
Hongji Yang ◽  
Alan O’Callaghan

When developing a software system, there are a number of principles, paradigms, and tools available to choose from. For a specific platform or programming language, a standard way can usually be found to archive the ultimate system; for example, a combination of an incremental development process, object-oriented analysis and design, and a well supported CASE (Computer-Aided Software Engineering) tool. Regardless of the technology to be adopted, the final outcome of the software development is always a working software system. However, when it comes to software reengineering, there is rather less consensus on either approaches or outcomes. Shall we use black-box or white-box reverse engineering for program understanding? Shall we produce data and control flow graphs, or some kind of formal specifications as the output of analysis? Each of these techniques has its pros and cons of tackling various software reengineering problems, and none of them on its own suffices to a whole reengineering project. A proper integration of various techniques capable of solving a specific issue could be an effective way to unravel a complicated software system. This kind of integration has to be done from an architectural point of view. One of the most exciting outcomes of recent efforts on software architecture is the Object Management Group’s (OMG) Model-Driven Architecture (MDA). MDA provides a unified framework for developing middleware-based modern distributed systems, and also a definite goal for software reengineering. This chapter presents a unified software reengineering methodology based on Model-Driven Architecture, which consists of a framework, a process, and related techniques.


2019 ◽  
Vol 16 (4) ◽  
pp. 172988141986216 ◽  
Author(s):  
Bin He ◽  
Shuai Wang ◽  
Yongjia Liu

Underactuated robotics is an emerging research direction in the field of robotics. The control input of the underactuated robot is less than the degree of freedom of the system. It has the advantages of lightweight, low energy consumption, excellent performance, and broad development prospects. This article reviews the state of the art on underactuated robotics. On the basis of previous studies, this article takes the non-holonomic constraint equation as the entry point to classify and summarize underactuated robot and their common mechanisms. The controllability of underactuated robot is further discussed. The control flow of underactuated robot is described based on the open–closed control method. In the closed-loop control, the control method based on the fuzzy system is mainly used. Finally, the difficulties in the current research of underactuated robot are summarized, and the future research directions are prospected.


Author(s):  
Strauss Cunha Carvalho ◽  
Renê Esteves Maria ◽  
Leonardo Schmitt ◽  
Luiz Alberto Vieira Dias
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document