Investigation on Statistical-based Detection Techniques For Control Valve Stiction Detection

Control valve stiction is one of the main causes that can affect the performance of a control loop. As the final control element, it can cause disruptions towards the operations especially on the plant production of oil and gas industry. An initiative had been made in 1989 where a stiction detection method is first developed to detect stiction in control valve. Since then, many methods are produced and redeveloped but only few uses the statistical-based methods. Hence, this project will cover statistical-based methods which had once been used for fault detection and will be tested for the effectiveness in detecting control valve stiction. Two case studies are chosen which are simulation case study involving stiction and non-stiction conditions namely, well-tuned controller (Base case), tightly-tuned controller (Case 1), presence of disturbances controller (Case 2) and presence of stiction controller (Case 3). Another case study is the real industrial data from a chemical plant. The process output (pv) and controller output (op) for each case are generated based on nonlinear principle component analysis (NLPCA) method. Two statistical-based methods are chosen to be tested which are generalized likelihood ratio (GLR) test as well as error testing method. Based on the results of testing for method 1, there are some limitations for GLR test method to detect between the presence of stiction and the presence of disturbances in the system. However, for method 2, it can be seen that the error testing method focusing at the root mean squared error (RMSE) calculation is an effective tool and method to detect stiction and manage to differentiate stiction and non-stiction system for the simulation and real industrial case studies chosen

Single phase inverter system using proportional resonant current control

This paper presents the harmonic reduction performance of proportional resonant (PR) current controller in single phase inverter system connected to nonlinear load. In the study, proportional resonant current controller and low pass filter is discussed to eliminate low order harmonics injection in single phase inverter system. The potential of nonlinear load in producing harmonics is showed and identified by developing a nonlinear load model using a full bridge rectifier circuit. The modelling and simulation is done in MATLAB Simulink while harmonic spectrum results are obtained using Fast Fourier Transfor. End result show PR current controller capability to overcome the injection of current harmonic problems thus improved the overall total harmonic distortion (THD)

Report from GI-Dagstuhl Seminar 16394: Software Performance Engineering in the DevOps World

This report documents the program and the outcomes of GI-Dagstuhl Seminar 16394 "Software Performance Engineering in the DevOps World". The seminar addressed the problem of performance-aware DevOps. Both, DevOps and performance engineering have been growing trends over the past one to two years, in no small part due to the rise in importance of identifying performance anomalies in the operations (Ops) of cloud and big data systems and feeding these back to the development (Dev). However, so far, the research community has treated software engineering, performance engineering, and cloud computing mostly as individual research areas. We aimed to identify cross-community collaboration, and to set the path for long-lasting collaborations towards performance-aware DevOps. The main goal of the seminar was to bring together young researchers (PhD students in a later stage of their PhD, as well as PostDocs or Junior Professors) in the areas of (i) software engineering, (ii) performance engineering, and (iii) cloud computing and big data to present their current research projects, to exchange experience and expertise, to discuss research challenges, and to develop ideas for future collaborations

Rapid Economic Growth at the Cost of Environment Degradation? Panel Data Evidience from BRIC Economies

The paper investigates whether the decline in environmental quality in BRIC economies is due to high energy consumption level which is a resultant of rapid economic growth. We answer this using environmental, macroeconomic and financial variables along with Kyoto Protocol indicators based on panel data from 1992 to 2004.http://deepblue.lib.umich.edu/bitstream/2027.42/64409/1/wp908.pd

Certification of quality management systems under ISO 9000 versus business bottom line: empirical evidence

Esta investigación, tiene como objetivo principal la posible correlación entre la calidad y los beneficios que proporciona, tanto humanos, económicos y tecnológicos, materializados en un incremento de los resultados, lo que permitirá algunas empresas resolver los desafíos y oportunidades en el mundo de hoy, cada vez más interconectado. La aplicación de las herramientas de calidad puede resultar clave para el éxito de las organizaciones, proporcionando una ventaja competitiva en la actual economía mundial y una mayor satisfacción de sus clientes en términos del valor que perciben. De forma más explicita, esta investigación pretende demostrar la relación entre la certificación ISO 9001, la medición de los costes de la calidad y los resultados de la empresa, sobre la base de un estudio empírico. Por lo tanto, este trabajo de investigación tiene como objetivo estudiar y entender la importancia de aplicar sistemas de gestión de calidad total y control de costes en la gestión de la calidad de la empresa. En particular, estamos especialmente interesados en si la aplicación de estas herramientas aumenta el resultado de la empresa. Para lograr este objetivo, hemos desarrollado un estudio empírico de las empresas certificadas por el NP EN ISO 9001:2000, en Portugal, en la región de Ribatejo (Distrito de Santarém) y recopilar datos sobre si la empresa añade valor.Quality is the main focus of the current paper, as well as the great importance of its benefits to businesses. These benefits, which shall consubstantiate increased earnings, are deemed as significant to companies from an economical, technological and human resources point of view, considering also that its development may facilitate the entrepreneurial capacity of firms to deal with the ever evolving challenges and opportunities of the current interconnected world. More specifically, the current investigation aims to demonstrate the existence of an objective relation between the standard ISO 9000 certification, quality costs measuring and earnings, based on our empirical study. So, the current investigation was aimed to study and understand the importance of the implementation of total quality management systems as well as quality cost control in a firm’s quality management system. In particular we would like to understand whether the implementation of quality tools has a positive influence in a firm’s earnings. In order to fulfil such objective within the Portuguese context, we have developed an empirical study which targeted companies accredited under NP EN ISO 9001:2000 on a particular sub-region of Portugal (Ribatejo, Santarém’s district), and collected data in order to verify whether the implementation of such quality management systems adds value to those companies

Predicting and Evaluating Software Model Growth in the Automotive Industry

The size of a software artifact influences the software quality and impacts the development process. In industry, when software size exceeds certain thresholds, memory errors accumulate and development tools might not be able to cope anymore, resulting in a lengthy program start up times, failing builds, or memory problems at unpredictable times. Thus, foreseeing critical growth in software modules meets a high demand in industrial practice. Predicting the time when the size grows to the level where maintenance is needed prevents unexpected efforts and helps to spot problematic artifacts before they become critical. Although the amount of prediction approaches in literature is vast, it is unclear how well they fit with prerequisites and expectations from practice. In this paper, we perform an industrial case study at an automotive manufacturer to explore applicability and usability of prediction approaches in practice. In a first step, we collect the most relevant prediction approaches from literature, including both, approaches using statistics and machine learning. Furthermore, we elicit expectations towards predictions from practitioners using a survey and stakeholder workshops. At the same time, we measure software size of 48 software artifacts by mining four years of revision history, resulting in 4,547 data points. In the last step, we assess the applicability of state-of-the-art prediction approaches using the collected data by systematically analyzing how well they fulfill the practitioners' expectations. Our main contribution is a comparison of commonly used prediction approaches in a real world industrial setting while considering stakeholder expectations. We show that the approaches provide significantly different results regarding prediction accuracy and that the statistical approaches fit our data best

Explaining differences in sub-national patterns of clean technology transfer to China and India

The Kyoto Protocol’s Clean Development Mechanism (CDM) has the capacity to incentivize the international transfer of environmentally sound technologies. Given that both countries are expected to have similar incentives when managing the distribution of technology transfer within the country, why do sub-national patterns in the allocation of projects with technology transfer differ? Using comparable political–economic data compiled for China and India, we offer an explanation for these differences. In China, where the government regards the CDM as a tool for achieving sustainable development, technology transfer is concentrated in provinces that need it the most and that are most conducive to receiving transfers (i.e., economically less developed, yet heavily industrialized provinces). In India, where the government takes on a “laissez-faire” approach to the CDM, neither level of economic development nor that of industrialization affects clean technology transfer. In this regard, although the incentives are similar, the capacity to pursue them is not comparable. We test these hypotheses using data on CDM technology transfer across Chinese provinces and Indian states during the 6-year period from 2004 to 2010

Developing a distributed electronic health-record store for India

The DIGHT project is addressing the problem of building a scalable and highly available information store for the Electronic Health Records (EHRs) of the over one billion citizens of India