135,622 research outputs found
Research Findings on Empirical Evaluation of Requirements Specifications Approaches
Numerous software requirements specification (SRS) approaches have been proposed in software engineering. However, there has been little empirical evaluation of the use of these approaches in specific contexts. This paper describes the results of a mapping study, a key instrument of the evidence-based paradigm, in an effort to understand what aspects of SRS are evaluated, in which context, and by using which research method. On the basis of 46 identified and categorized primary studies, we found that understandability is the most commonly evaluated aspect of SRS, experiments are the most commonly used research method, and the academic environment is where most empirical evaluation takes place
Evolution of statistical analysis in empirical software engineering research: Current state and steps forward
Software engineering research is evolving and papers are increasingly based
on empirical data from a multitude of sources, using statistical tests to
determine if and to what degree empirical evidence supports their hypotheses.
To investigate the practices and trends of statistical analysis in empirical
software engineering (ESE), this paper presents a review of a large pool of
papers from top-ranked software engineering journals. First, we manually
reviewed 161 papers and in the second phase of our method, we conducted a more
extensive semi-automatic classification of papers spanning the years 2001--2015
and 5,196 papers. Results from both review steps was used to: i) identify and
analyze the predominant practices in ESE (e.g., using t-test or ANOVA), as well
as relevant trends in usage of specific statistical methods (e.g.,
nonparametric tests and effect size measures) and, ii) develop a conceptual
model for a statistical analysis workflow with suggestions on how to apply
different statistical methods as well as guidelines to avoid pitfalls. Lastly,
we confirm existing claims that current ESE practices lack a standard to report
practical significance of results. We illustrate how practical significance can
be discussed in terms of both the statistical analysis and in the
practitioner's context.Comment: journal submission, 34 pages, 8 figure
Internal combustion engine sensor network analysis using graph modeling
In recent years there has been a rapid development in technologies for smart monitoring applied to many different areas (e.g. building automation, photovoltaic systems, etc.). An intelligent monitoring system employs multiple sensors distributed within a network to extract useful information for decision-making. The management and the analysis of the raw data derived from the sensor network includes a number of specific challenges still unresolved, related to the different communication standards, the heterogeneous structure and the huge volume of data.
In this paper we propose to apply a method based on complex network theory, to evaluate the performance of an Internal Combustion Engine. Data are gathered from the OBD sensor subset and from the emission analyzer. The method provides for the graph modeling of the sensor network, where the nodes are represented by the sensors and the edge are evaluated with non-linear statistical correlation functions applied to the time series pairs.
The resulting functional graph is then analyzed with the topological metrics of the network, to define characteristic proprieties representing useful indicator for the maintenance and diagnosis
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A survey of simulation techniques in commerce and defence
Despite the developments in Modelling and Simulation (M&S) tools and techniques over the past years, there has been a gap in the M&S research and practice in healthcare on developing a toolkit to assist the modellers and simulation practitioners with selecting an appropriate set of techniques. This study is a preliminary step towards this goal. This paper presents some results from a systematic literature survey on applications of M&S in the commerce and defence domains that could inspire some improvements in the healthcare. Interim results show that in the commercial sector Discrete-Event Simulation (DES) has been the most widely used technique with System Dynamics (SD) in second place. However in the defence sector, SD has gained relatively more attention. SD has been found quite useful for qualitative and soft factors analysis. From both the surveys it becomes clear that there is a growing trend towards using hybrid M&S approaches
Integrate the GM(1,1) and Verhulst models to predict software stage effort
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2009 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.Software effort prediction clearly plays a crucial role in software project management. In keeping with more dynamic approaches to software development, it is not sufficient to only predict the whole-project effort at an early stage. Rather, the project manager must also dynamically predict the effort of different stages or activities during the software development process. This can assist the project manager to reestimate effort and adjust the project plan, thus avoiding effort or schedule overruns. This paper presents a method for software physical time stage-effort prediction based on grey models GM(1,1) and Verhulst. This method establishes models dynamically according to particular types of stage-effort sequences, and can adapt to particular development methodologies automatically by using a novel grey feedback mechanism. We evaluate the proposed method with a large-scale real-world software engineering dataset, and compare it with the linear regression method and the Kalman filter method, revealing that accuracy has been improved by at least 28% and 50%, respectively. The results indicate that the method can be effective and has considerable potential. We believe that stage predictions could be a useful complement to whole-project effort prediction methods.National Natural Science Foundation of
China and the Hi-Tech Research
and Development Program of Chin
Effervescent Breakup and Combustion of Liquid Fuels: Experiment and Modelling
Tato práce se zaměřuje na oblast effervescentnĂch sprejĹŻ a jejich aplikace na kapalnĂ© spalovánĂ s dĹŻrazem na prĹŻmyslovĂ© spalovacĂ komory. Oba aspekty – modelovánĂ a experiment – jsou Ĺ™ešeny. Práce obsahuje obecnĂ˝ Ăşvod, ve kterĂ©m jsou vysvÄ›tleny základnĂ jevy rozpadu kapaliny a vĂĹ™ivĂ©ho spalovánĂ a dále je pĹ™edstavena effervescentnĂ atomizace. PotĂ© jsou popsány pouĹľitĂ© experimentálnĂ postupy jak pro měřenĂ spreje, tak pro měřenĂ tepelnĂ˝ch tokĹŻ do stÄ›n pĹ™i spalovánĂ. V následujĂcĂ kapitole jsou popsány numerickĂ© modely a jejich podstata je vysvÄ›tlena. Jsou zde uvedeny modely pro rozpad spreje, turbulenci a spalovánĂ pouĹľitĂ© bÄ›hem vĂ˝zkumu. VlastnĂ vĂ˝sledky práce jsou uvedeny formou samostatnĂ˝ch ÄŤlánkĹŻ (vydanĂ˝ch nebo pĹ™ijatĂ˝ch) s dodateÄŤnou částĂ vÄ›novanou nepublikovanĂ˝m relevantnĂm vĂ˝sledkĹŻm. Bylo zjištÄ›no, Ĺľe standardnĂ modely sprejĹŻ jsou do jistĂ© mĂry schopny popsat effervescentnĂ spreje. NicmĂ©nÄ› aby bylo moĹľnĂ© predikovat plamen kapalnĂ©ho spreje, jsou zapotĹ™ebĂ detailnÄ›jšà modely sprejĹŻ, kterĂ© dokážà pĹ™esnÄ› zachytit zmÄ›nu prĹŻmÄ›rĹŻ kapek v radiálnĂm a axiálnĂm smÄ›ru. ExperimentálnĂ měřenĂ effervescentnĂch sprejĹŻ bylo provedeno pomocĂ navrhnutĂ© metodiky. VĂ˝sledky měřenĂ byly analyzovány s dĹŻrazem na radiálnĂ a axiálnĂ vĂ˝voj prĹŻmÄ›rĹŻ kapek a nÄ›kterĂ© novĂ© jevy byly popsány. NepĹ™Ămá ĂşmÄ›rnost mezi gas-liquid-ratio a stĹ™ednĂm prĹŻmÄ›rem kapek byla potvrzena. Dále by popsán jev, kdy pro rĹŻznĂ© axiálnĂ vzdálenosti kterĂ© dojde k ĂşplnĂ©mu pĹ™evrácenĂ závislosti stĹ™ednĂho prĹŻmÄ›ru na axiálnĂ vzdálenosti. V závÄ›ru je uvedeno shrnutĂ, kterĂ© rekapituluje hlavnĂ vĂ˝sledkĹŻ a závÄ›ry. V závÄ›reÄŤnĂ˝ch poznámkách je nastĂnÄ›n moĹľnĂ˝ budoucĂ postup. ExperimentálnĂ data pro ověřovánĂ budoucĂch effervescentnĂch modelĹŻ jsou poskytnuta.This thesis presents an investigation of effervescent sprays and their application to spray combustion with emphasis on large-scale combustors. Both aspects – modelling and experiment – are addressed. The thesis contains a general introductory part, where underlying phenomena of spray forming and turbulent combustion are explained and effervescent atomization is presented. Then, adopted experimental approaches are described both for the spray measurement and for the measurement of wall heat fluxes during combustion experiments. In the following chapter numerical models and their philosophy is discussed. Models for spray formation, turbulence and combustion adopted during the research are introduced and explained. The actual results of the thesis are presented in form of separate papers (published or accepted for publication) with an additional section devoted to unpublished relevant results. It is found that standard spray models can to some extent represent effervescent sprays. However, in order to predict a spray flame more detailed spray models are needed in order to describe accurately radial and axial variations of drop sizes. Numerous experimental measurements of effervescent sprays are performed using a proposed methodology. Drop size data are analysed with emphasis on radial and axial drop size evolutions and some new phenomena are described. The inverse relationship between gas-liquid-ratio and mean diameter has been confirmed. Moreover a complete reversal in radial mean diameter trends for various axial locations has been described. Finally, a result summary is put forward that recapitulates the main accomplishments and conclusions. In the closing remarks possible future research is outlined. Experimental data for future effervescent model validations are disclosed.
Electrowetting-Based Digital Microfluidics Platform for Automated Enzyme-linked Immunosorbent Assay
Electrowetting is the effect by which the contact angle of a droplet exposed to a surface charge is modified. Electrowetting-on-dielectric (EWOD) exploits the dielectric properties of thin insulator films to enhance the charge density and hence boost the electrowetting effect. The presence of charges results in an electrically induced spreading of the droplet which permits purposeful manipulation across a hydrophobic surface. Here, we demonstrate EWOD-based protocol for sample processing and detection of four categories of antigens, using an automated surface actuation platform, via two variations of an Enzyme-Linked Immunosorbent Assay (ELISA) methods. The ELISA is performed on magnetic beads with immobilized primary antibodies which can be selected to target a specific antigen. An antibody conjugated to HRP binds to the antigen and is mixed with H 2O 2/Luminol for quantification of the captured pathogens. Assay completion times of between 6 and 10 min were achieved, whilst minuscule volumes of reagents were utilized.Peer reviewe
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