Early Quantitative Assessment of Non-Functional Requirements

Non-functional requirements (NFRs) of software systems are a well known source of uncertainty in effort estimation. Yet, quantitatively approaching NFR early in a project is hard. This paper makes a step towards reducing the impact of uncertainty due to NRF. It offers a solution that incorporates NFRs into the functional size quantification process. The merits of our solution are twofold: first, it lets us quantitatively assess the NFR modeling process early in the project, and second, it lets us generate test cases for NFR verification purposes. We chose the NFR framework as a vehicle to integrate NFRs into the requirements modeling process and to apply quantitative assessment procedures. Our solution proposal also rests on the functional size measurement method, COSMIC-FFP, adopted in 2003 as the ISO/IEC 19761 standard. We extend its use for NFR testing purposes, which is an essential step for improving NFR development and testing effort estimates, and consequently for managing the scope of NFRs. We discuss the advantages of our approach and the open questions related to its design as well

Non-functional requirements: size measurement and testing with COSMIC-FFP

The non-functional requirements (NFRs) of software systems are well known to add a degree of uncertainty to process of estimating the cost of any project. This paper contributes to the achievement of more precise project size measurement through incorporating NFRs into the functional size quantification process. We report on an initial solution proposed to deal with the problem of quantitatively assessing the NFR modeling process early in the project, and of generating test cases for NFR verification purposes. The NFR framework has been chosen for the integration of NFRs into the requirements modeling process and for their quantitative assessment. Our proposal is based on the functional size measurement method, COSMIC-FFP, adopted in 2003 as the ISO/IEC 19761 standard. Also in this paper, we extend the use of COSMIC-FFP for NFR testing purposes. This is an essential step for improving NFR development and testing effort estimates, and consequently for managing the scope of NFRs. We discuss the merits of the proposed approach and the open questions related to its design

High-frequency behavior of FeN thin films fabricated by reactive sputtering

We investigated high-frequency behavior of FeN thin films prepared by reactive sputtering through ferromagnetic resonance (FMR) and its relationship with the static magnetic properties. The FMR was observed in the frequency range from 2 to 18 GHz in the FeN films fabricated at proper nitrogen flow rate (NFR). In those FeN thin films, a decrease of the saturation magnetization and the corresponding decrease of the FMR frequency were observed as NFR was increased during the deposition. The external field dependences of the FMR frequencies were well fit to the Kittel formula and the Land\'e g-factors determined from the fit were found to be very close to the free electron value. The high-field damping parameters were almost insensitive to the growth condition of NFR. However, the low-field damping parameters exhibited high sensitivity to NFR very similar to the dependence of the hard-axis coercivity on NFR, suggesting that extrinsic material properties such as impurities and defect structures could be important in deciding the low-field damping behavior.Comment: 18 pages, 6 figures, ICAMD 2015 conferenc

Untersuchung der Eignung nozizeptiver Reflexe zur Quantifizierung der endogenen Schmerzmodulation und zur Beurteilung der Analgesie unter Allgemeinanästhesie

Introduction: Nociceptive reflexes like the nociceptive flexion reflex (NFR) or the pupillary dilation reflex (PDR) are used to measure pain and nociception in wake patients and patients under sedation. However the accuracy of these methods regarding their different fields of application is unknown. We therefore conducted three studies: in study A we measured the test-retest reliability of the endogenous pain modulation of the NFR by a conditioning stimulus, in order to examine, if the NFR is able to measure the individual ability to inhibit pain. In study B we investigated, how accurate the NFR can be scored automatically in electromyography (EMG) recordings and optimized this automatic NFR scoring procedure. In study C we investigated, how accurate immediate postoperative pain and delayed tracheal extubation can be predicted by the nociceptive reflexes PDR and NFR measured during general anaesthesia. Method: In study A we measured the conditioned pain modulation (CPM) in 40 healthy participants at two sessions through the changes in size of the NFR and in subjective pain ratings caused by a painful hot water stimulus compared to the changes caused by a painless control stimulus. In study B we compared different EMG scoring criteria and their thresholds for automatic NFR detection with expert ratings in two independent data sets derived from 60 healthy participants each and calculated multivariable classification models to improve the automatic NFR detection. In study C we measured the PDR and NFR of 110 patients before and during general anaesthesia for primary hip arthroplasty. Results: Study A showed a good test-retest reliability for the CPM of the NFR and the CPM of pain ratings as measures of endogenous pain modulation. Study B showed that in automatic NFR detection by single scoring criteria the Interval-Peak-Z-Score matches the expert ratings with highest accuracy, while multivariable EMG scoring criteria further increase this accuracy significantly. Study C showed that the PDR and NFR thresholds measured during general anaesthesia correlate with delayed tracheal extubation and the PDR threshold correlate with the immediate postoperative pain. Conclusions: Our results from study A show that the NFR is a reliable measure of endogenous pain modulation. Our results from study B show that the NFR can be automatically detected with high accuracy, which can be further improved by multivariable EMG classification models. Our results from study C show that nociceptive reflexes measured during general anaesthesia reflect the balance between nociception and analgesia.Einleitung: Nozizeptive Reflexe wie der Nozizeptive Flexorenreflex (NFR) und der Pupillendilatationsreflex (PDR) werden zur Quantifizierung von Schmerz und Nozizeption bei wachen und sedierten Patienten verwendet. Jedoch gibt es bisher über die Genauigkeit dieser Methoden in den unterschiedlichen Einsatzgebieten nur wenige Daten. Wir führten daher drei Studien durch: In Studie A untersuchten wir die Test-Retest-Reliabilität der endogenen Schmerzmodulation des NFR durch einen konditionierenden Stimulus, um zu prüfen, ob sich der NFR als Maß der körpereigenen Schmerzhemmung eignet. In Studie B untersuchten wir, wie genau sich der NFR automatisiert im Elektromyogramm (EMG) erkennen lässt und optimierten diese automatisierte Reflexdetektion. In Studie C untersuchten wir, wie genau sich der akute postoperative Schmerz und die Aufwachdauer nach einer Operation anhand der noch während der Allgemeinanästhesie gemessenen nozizeptiven Reflexe NFR und PDR vorhersagen lassen. Methodik: In Studie A bestimmten wir das Ausmaß der Conditioned Pain Modulation (CPM) von 40 gesunden Probanden zu zwei Zeitpunkten anhand der Änderung von NFR und subjektiver Schmerzbewertung durch einen schmerzhaften Heißwasserstimulus im Vergleich zur Änderung durch einen schmerzlosen Kontrollstimulus. In Studie B verglichen wir in zwei Datensätzen von je 60 gesunden Probanden verschiedene Kriterien und deren Schwellenwerte zur automatisierten NFR-Detektion im EMG mit dem Goldstandard, der Bewertung durch Experten, und entwickelten zur Verbesserung der Reflexdetektion multivariable Modelle. In Studie C untersuchten wir den PDR und den NFR vor und während einer Allgemeinanästhesie an 110 Patienten zur primären Hüftarthroplastik sowie die Aufwachdauer und das Schmerzausmaß nach der Allgemeinanästhesie. Ergebnisse: Studie A zeigte eine gute Test-Retest-Reliabilität der CPM des NFR sowie der CPM der subjektiven Schmerzbewertung. Studie B zeigte für die automatisierte NFR-Detektion durch den EMG-Parameter Interval-Peak-Z-Score eine hohe Übereinstimmung mit der Bewertung durch Experten, die durch Einbezug weiterer EMG-Parameter mittels multivariabler Modelle signifikant verbessert werden konnte. Studie C zeigte, dass die unter Allgemeinanästhesie bestimmten Schwellenwerte des PDR und des NFR mit der Aufwachdauer korrelieren und dass der Schwellenwert des PDR auch mit dem akuten postoperativen Schmerz korreliert. Schlussfolgerung: Die Ergebnisse aus Studie A zeigen, dass der NFR geeignet ist, die endogene Schmerzmodulation reliabel abzubilden. Die Ergebnisse aus Studie B zeigen, dass der NFR mit einer hohen Genauigkeit automatisiert im EMG erkannt werden kann und multivariable Modelle diese Reflexdetektion noch weiter verbessern können. Die Ergebnisse aus Studie C zeigen, dass die nozizeptiven Reflexe auch unter Allgemeinanästhesie in der Lage sind, die Balance zwischen Nozizeption und Analgesie widerzuspiegeln

Systematic alteration of ATAC-seq for profiling open chromatin in cryopreserved nuclei preparations from livestock tissues.

The use of Assay for Transposase-Accessible Chromatin (ATAC-seq) to profile chromatin accessibility has surged over the past years, but its applicability to tissues has been very limited. With the intent of preserving nuclear architecture during long-term storage, cryopreserved nuclei preparations from chicken lung were used to optimize ATAC-seq. Sequencing data were compared with existing DNase-seq, ChIP-seq, and RNA-seq data to evaluate library quality, ultimately resulting in a modified ATAC-seq method capable of generating high quality chromatin accessibility data from cryopreserved nuclei preparations. Using this method, nucleosome-free regions (NFR) identified in chicken lung overlapped half of DNase-I hypersensitive sites, coincided with active histone modifications, and specifically marked actively expressed genes. Notably, sequencing only the subnucleosomal fraction dramatically improved signal, while separation of subnucleosomal reads post-sequencing did not improve signal or peak calling. The broader applicability of this modified ATAC-seq technique was tested using cryopreserved nuclei preparations from pig tissues, resulting in NFR that were highly consistent among biological replicates. Furthermore, tissue-specific NFR were enriched for binding motifs of transcription factors related to tissue-specific functions, and marked genes functionally enriched for tissue-specific processes. Overall, these results provide insights into the optimization of ATAC-seq and a platform for profiling open chromatin in animal tissues

How do software architects consider non-functional requirements: an exploratory study

© 2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, 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 component of this work in other works.Dealing with non-functional requirements (NFRs) has posed a challenge onto software engineers for many years. Over the years, many methods and techniques have been proposed to improve their elicitation, documentation, and validation. Knowing more about the state of the practice on these topics may benefit both practitioners' and researchers' daily work. A few empirical studies have been conducted in the past, but none under the perspective of software architects, in spite of the great influence that NFRs have on daily architects' practices. This paper presents some of the findings of an empirical study based on 13 interviews with software architects. It addresses questions such as: who decides the NFRs, what types of NFRs matter to architects, how are NFRs documented, and how are NFRs validated. The results are contextualized with existing previous work.Peer ReviewedPostprint (author’s final draft

Towards a scope management of non-functional requirements in requirements engineering

Getting business stakeholders’ goals formulated clearly and project scope defined realistically increases the chance of success for any application development process. As a consequence, stakeholders at early project stages acquire as much as possible knowledge about the requirements, their risk estimates and their prioritization. Current industrial practice suggests that in most software projects this scope assessment is performed on the user’s functional requirements (FRs), while the non-functional requirements (NFRs) remain, by and large, ignored. However, the increasing software complexity and competition in the software industry has highlighted the need to consider NFRs as an integral part of software modeling and development. This paper contributes towards harmonizing the need to build the functional behavior of a system with the need to model the associated NFRs while maintaining a scope management for NFRs. The paper presents a systematic and precisely defined model towards an early integration of NFRs within the requirements engineering (RE). Early experiences with the model indicate its ability to facilitate the process of acquiring the knowledge on the priority and risk of NFRs

Experimental study of the instationary flow between two ducted Counter-rotating rotors

The purpose of this work is to study experimentally the aerodynamic characteristics of a subsonic counter-rotating axial-flow fans system operating in a ducted configuration. The fans of diameter D = 375 mm were designed to match the specification point using an original iterative method: the front rotor blade cascade is designed with a conventional inverse method, setting the radial distribution of the Euler work. The through-flow is then computed using an axisymmetric and radial equilibrium asumption, with empirical models of losses. The rear rotor is not conventional but is designed to straighten the radial profile of the tangential velocity. The design of the front rotor is then modified until the stage meets the requirements. The experimental setup is arranged such that the rotation rate of each fan is independently controlled and that the axial distance between the rotors can be varied from 17% to 310% of the mid-span chord length. Systematic measurements of the global performances and local measurements of the velocity field and of the wall pressure fluctuations are performed, in order to first validate the design method, and to explore the effects of the two specific free parameters of the system: the axial spacing and the ratio of rotation rates. The results show that the efficiency is strongly increased compared to a conventional rotor or to a rotor-stator stage. The developed design method slightly over-predicts the pressure rise and slightly under-predicts the best ratio of rotation rates. Flow angle measurements downstream of the stage show that the outflow is not completely straightened at the design point. Finally, the system is highly efficient on a wide range of flow-rates and pressure rises: this system has thus a very flexible use, with a large patch of high efficient operating points in the parameter space

Optimizing Scrubbing by Netlist Analysis for FPGA Configuration Bit Classification and Floorplanning

Existing scrubbing techniques for SEU mitigation on FPGAs do not guarantee an error-free operation after SEU recovering if the affected configuration bits do belong to feedback loops of the implemented circuits. In this paper, we a) provide a netlist-based circuit analysis technique to distinguish so-called critical configuration bits from essential bits in order to identify configuration bits which will need also state-restoring actions after a recovered SEU and which not. Furthermore, b) an alternative classification approach using fault injection is developed in order to compare both classification techniques. Moreover, c) we will propose a floorplanning approach for reducing the effective number of scrubbed frames and d), experimental results will give evidence that our optimization methodology not only allows to detect errors earlier but also to minimize the Mean-Time-To-Repair (MTTR) of a circuit considerably. In particular, we show that by using our approach, the MTTR for datapath-intensive circuits can be reduced by up to 48.5% in comparison to standard approaches