422,006 research outputs found

    Quality-aware model-driven service engineering

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    Service engineering and service-oriented architecture as an integration and platform technology is a recent approach to software systems integration. Quality aspects ranging from interoperability to maintainability to performance are of central importance for the integration of heterogeneous, distributed service-based systems. Architecture models can substantially influence quality attributes of the implemented software systems. Besides the benefits of explicit architectures on maintainability and reuse, architectural constraints such as styles, reference architectures and architectural patterns can influence observable software properties such as performance. Empirical performance evaluation is a process of measuring and evaluating the performance of implemented software. We present an approach for addressing the quality of services and service-based systems at the model-level in the context of model-driven service engineering. The focus on architecture-level models is a consequence of the black-box character of services

    Dynamic Modelling, Measurement and Control of Co-rotating Twin-Screw Extruders

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    Co-rotating twin-screw extruders are unique and versatile machines that are used widely in the plastics and food processing industries. Due to the large number of operating variables and design parameters available for manipulation and the complex interactions between them, it cannot be claimed that these extruders are currently being optimally utilised. The most significant improvement to the field of twin-screw extrusion would be through the provision of a generally applicable dynamic process model that is both computationally inexpensive and accurate. This would enable product design, process optimisation and process controller design to be performed cheaply and more thoroughly on a computer than can currently be achieved through experimental trials. This thesis is divided into three parts: dynamic modelling, measurement and control. The first part outlines the development of a dynamic model of the extrusion process which satisfies the above mentioned criteria. The dynamic model predicts quasi-3D spatial profiles of the degree of fill, pressure, temperature, specific mechanical energy input and concentrations of inert and reacting species in the extruder. The individual material transport models which constitute the dynamic model are examined closely for their accuracy and computational efficiency by comparing candidate models amongst themselves and against full 3D finite volume flow models. Several new modelling approaches are proposed in the course of this investigation. The dynamic model achieves a high degree of simplicity and flexibility by assuming a slight compressibility in the process material, allowing the pressure to be calculated directly from the degree of over-fill in each model element using an equation of state. Comparison of the model predictions with dynamic temperature, pressure and residence time distribution data from an extrusion cooking process indicates a good predictive capability. The model can perform dynamic step-change calculations for typical screw configurations in approximately 30 seconds on a 600 MHz Pentium 3 personal computer. The second part of this thesis relates to the measurement of product quality attributes of extruded materials. A digital image processing technique for measuring the bubble size distribution in extruded foams from cross sectional images is presented. It is recognised that this is an important product quality attribute, though difficult to measure accurately with existing techniques. The present technique is demonstrated on several different products. A simulation study of the formation mechanism of polymer foams is also performed. The measurement of product quality attributes such as bulk density and hardness in a manner suitable for automatic control is also addressed. This is achieved through the development of an acoustic sensor for inferring product attributes using the sounds emanating from the product as it leaves the extruder. This method is found to have good prediction ability on unseen data. The third and final part of this thesis relates to the automatic control of product quality attributes using multivariable model predictive controllers based on both direct and indirect control strategies. In the given case study, indirect control strategies, which seek to regulate the product quality attributes through the control of secondary process indicators such as temperature and pressure, are found to cause greater deviations in product quality than taking no corrective control action at all. Conversely, direct control strategies are shown to give tight control over the product quality attributes, provided that appropriate product quality sensors or inferential estimation techniques are available

    Performance measurement of employee using an integrated 360° feedback system and AHP method: A case study of municipality

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    Performance measurement plays an essential role on accelerating the efficiency of any organization. There are literally different methods for measuring the relative performance of a particular unit and many of them are involved considering various criteria. In this paper, we propose 360° feedback system for performance measurement of all employees who work for municipality of the city of Tabas located in east part of Iran. The proposed model of this paper also uses hierarchical method to cluster different attributes based on various characteristics and implements analytical hierarchy process to find the relative importance of all items. The survey uses five personal characteristics including cognitive, technical, personal and human skills and for each major item, the proposed model considers various sub-criteria. The results indicate that technical and cognitive skills are the most important personal characteristics followed by human and personal characteristics. The results of this survey show that responsibility and quality of work are the most important employee characteristics

    Empirical Verification of the Weighted System of Criteria for the Elite Water Polo Players Quality Evaluation

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    The aim of this research was to check the validity of the weighed system of criteria for evaluating the actual quality of water polo players proposed by Hraste, Dizdar and Trnini}13. The authors have determined the attributes of the measurement instrument for assessment of the overall performance efficiency of elite water polo players. Based on the determined descriptive indicators, on the coefficients of the relative importance of criteria, and on the degree of the objectivity level (interobservers’ agreement) of the expert evaluations, it can be concluded that the measuring attributes (objectivity and sensitivity) for most of the criteria are in accordance with their relative importance coefficients for a particular position in the game. Consequently, a structure of relevant criteria is proposed for each play action position in the water polo game. The established instrument for evaluation the actual quality of the elite water polo players is a precondition to establish the professional system orientation, but it would also mean and a hypotheses for adequate design tactic model of play and a process of sports preparation. In succeeding steps of developing the system of criteria and its applicability, the latent structure of the criteria variables should be determined as well as overall importance of criteria with respect to the game of water polo

    Measuring customer expectations of service quality: case airline industry

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    Objectives of the Study The first theoretical objective of this study is to discuss the concept of service quality and find out the different approaches to measure service quality. The second objective is to define a process model for measuring service quality in air transportation based on literature review. Empirical objectives are to test the process model on selected customer group. Then, the results are used to investigate what services customers consider as the cornerstones of their flight experience, and if there are any differences in service quality preferences between respondent groups (such as male/female travelers, as well as business/leisure travelers). Academic background and methodology This study provides an overview of the services and service quality literature, taking airline industry as a subject for a case study. Airline industry is reviewed as well, and the importance of services, new service development as well as service quality is discussed. The academic literature is used to build up a service process model, which is tested to find out most important service quality attributes for the customers. A survey is chosen as a primary method of data collection. The target group includes young professionals with completed or about to be completed university education. Findings and conclusions The research concluded that the customers value basic services in service process such as information on tickets and flight schedule, communication in case of flight delay as well as no delays in baggage delivery. No significant differences were found between male and female passengers, expect for one case: male respondents evaluated employees’ appearance and attitude as more important compared to female respondents. Finally, from close correlations between some of the attributes, the conclusion can be made that the respondents do not differentiate between in-flight or ground services, and view the air travel experience as a whole

    A Structure-from-Motion Pipeline for Generating Digital Elevation Models for Surface-Runoff Analysis

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    Digital Elevation Models (DEMs) are used to derive information from the morphology of a land. The topographic attributes obtained from the DEM data allow the construction of watershed delineation useful for predicting the behavior of systems and for studying hydrological processes. Imagery acquired from Unmanned Aerial Vehicles (UAVs) and 3D photogrammetry techniques offer cost-effective advantages over other remote sensing methods such as LIDAR or RADAR. In particular, a high spatial resolution for measuring the terrain microtopography. In this work, we propose a Structure from Motion (SfM) pipeline using UAVs for generating high-resolution, high-quality DEMs for developing a rainfall-runoff model to study flood areas. SfM is a computer vision technique that simultaneously estimates the 3D coordinates of a scene and the pose of a camera that moves around it. The result is a 3D point cloud which we process to obtain a georeference model from the GPS information of the camera and ground control points. The pipeline is based on open source software OpenSfM and OpenDroneMap. Encouraging experimental results on a test land show that the produced DEMs meet the metrological requirements for developing a surface-runoff model. © Published under licence by IOP Publishing Ltd.This work has been partly funded by Universidad Tecnológica de Bolívar project (FI2006T2001). The authors thank Direccion de Investigaciones Universidad Tecnologica de Bolivar for their support

    Process Model Metrics for Quality Assessment of Computer-Interpretable Guidelines in PROform

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    Background: Clinical Practice Guidelines (CPGs) include recommendations to optimize patient care and thus have the potential to improve the quality and outcomes of healthcare. To achieve this, CPG recommendations are usually formalized in terms of Computer-Interpretable Guideline (CIG) languages. However, a clear understanding of CIG models may prove complicated, due to the inherent complexity of CPGs and the specificities of CIG languages. Drawing a parallel with the Business Process Management (BPM) and the Software Engineering fields, understandability and modifiability of CIG models can be regarded as primary quality attributes, in order to facilitate their validation, as well as their adaptation to accommodate evolving clinical evidence, by modelers (typically teams made up of clinical and IT experts). This constitutes a novel approach in this area of CIG development, where understandability and modifiability aspects have not been considered to date. Objective: In this paper, we define a comprehensive set of process model metrics for CIGs described in the PROforma CIG language, with the main objective of providing tools for quality assessment of CIG models in this language. Methods: To this end, we first reinterpret a set of metrics from the BPM field in terms of PROforma and then we define new metrics to capture the singularities of PROforma models. Additionally, we report on a set of experiments to assess the relationship between the structural and logical properties of CIG models, as measured by the proposed metrics, and their understandability and modifiability from the point of view of modelers, both clinicians and IT staff. For the analysis of the experiment results, we perform statistical analysis based on a generalized linear mixed model with binary logistic regression. Results: Our contribution includes the definition of a comprehensive set of metrics that allow measuring model quality aspects of PROforma CIG models, the implementation of tools and algorithms to assess the metrics for PROforma models, and the empirical validation of the proposed metrics as quality indicators. Conclusions: In light of the results, we conclude that the proposed metrics can be of great value, as they capture the PROforma-specific features in addition to those inspired by the general-purpose BPM metrics in the literature. In particular, the newly defined metrics for PROforma prevail as statistically significant when the whole CIG model is considered, which means that they better characterize its complexity. Consequently, the proposed metrics can be used as quality indicators of the understandability, and thereby maintainability, of PROforma CIGs

    Measuring Software Process: A Systematic Mapping Study

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    Context: Measurement is essential to reach predictable performance and high capability processes. It provides support for better understanding, evaluation, management, and control of the development process and project, as well as the resulting product. It also enables organizations to improve and predict its process’s performance, which places organizations in better positions to make appropriate decisions. Objective: This study aims to understand the measurement of the software development process, to identify studies, create a classification scheme based on the identified studies, and then to map such studies into the scheme to answer the research questions. Method: Systematic mapping is the selected research methodology for this study. Results: A total of 462 studies are included and classified into four topics with respect to their focus and into three groups based on the publishing date. Five abstractions and 64 attributes were identified, 25 methods/models and 17 contexts were distinguished. Conclusion: capability and performance were the most measured process attributes, while effort and performance were the most measured project attributes. Goal Question Metric and Capability Maturity Model Integration were the main methods and models used in the studies, whereas agile/lean development and small/medium-size enterprise were the most frequently identified research contexts.Ministerio de Economía y Competitividad TIN2013-46928-C3-3-RMinisterio de Economía y Competitividad TIN2016-76956-C3-2- RMinisterio de Economía y Competitividad TIN2015-71938-RED

    A metric for collaborative networks

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    The objective of this paper is to provide a metric that could be used to define success in acollaborative network. Design/methodology/approach - The methodology of this research consists of four stages: Review, Constructing, Testing and Description. Review stage comprised of a critical review of theliterature in order to understand the characteristics of collaborative network organisations and thereasons behind the successes and failures in collaborative networks. Construction stage resulted indevelopment of a metric for collaborative networks. Testing stage tested the model through case studyin a collaborative networks organisation. The outcome of the case study was discussed at thedescription stage to assess usability and usefulness of the metric for participants in turn to generatec onclusions
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