Search results for "Systems engineering"
showing 10 items of 1230 documents
Using SOM and PCA for analysing and interpreting data from a P-removal SBR
2008
This paper focuses on the application of Kohonen self-organizing maps (SOM) and principal component analysis (PCA) to thoroughly analyse and interpret multidimensional data from a biological process. The process is aimed at enhanced biological phosphorus removal (EBPR) from wastewater. In this work, SOM and PCA are firstly applied to the data set in order to identify and analyse the relationships among the variables in the process. Afterwards, K-means algorithm is used to find out how the observations can be grouped, on the basis of their similarity, in different classes. Finally, the information obtained using these intelligent tools is used for process interpretation and diagnosis. In the…
Qualitative analysis of goat and sheep production data using self-organizing maps
2009
The aim of this study was to analyse the relationship between different small ruminant livestock production systems with different levels of specialization. The analysis is carried out by using the self-organizing map. This tool allows high-dimensional input spaces to be mapped into much lower-dimensional spaces, thus making it much more straightforward to understand any set of data. These representations enable the visual extraction of qualitative relationships among variables (visual data mining), converting the data to maps. The data used in this study were obtained from surveys completed by farmers who are principally dedicated to goat and sheep production. With the self-organizing map …
Relative Vessel Motion Tracking using Sensor Fusion, Aruco Markers, and MRU Sensors
2017
This paper presents a novel approach for estimating the relative motion between two moving offshore vessels. The method is based on a sensor fusion algorithm including a vision system and two motion reference units (MRUs). The vision system makes use of the open-source computer vision library OpenCV and a cube with Aruco markers placed onto each of the cube sides. The Extended Quaternion Kalman Filter (EQKF) is used for bad pose rejection for the vision system. The presented sensor fusion algorithm is based on the Indirect Feedforward Kalman Filter for error estimation. The system is self-calibrating in the sense that the Aruco cube can be placed in an arbitrary location on the secondary ve…
Fiber-Optic Aqueous Dipping Sensor Based on Coaxial-Michelson Modal Interferometers
2009
Fiber-optic modal interferometers with a coaxial-Michelson configuration can be used to monitor aqueous solutions by simple dipping of few centimeters of a fiber tip. The fabrication of these sensors to work around 850 nm enables the use of compact, robust, and low-cost optical spectrum analyzers. The use of this type of portable sensor system to monitor sewage treatment plants is shown.
Space of signatures as inverse limits of Carnot groups
2021
We formalize the notion of limit of an inverse system of metric spaces with 1-Lipschitz projections having unbounded fibers. The construction is applied to the sequence of free Carnot groups of fixed rank n and increasing step. In this case, the limit space is in correspondence with the space of signatures of rectifiable paths in ℝn, as introduced by Chen. Hambly-Lyons’s result on the uniqueness of signature implies that this space is a geodesic metric tree. As a particular consequence we deduce that every path in ℝn can be approximated by projections of some geodesics in some Carnot group of rank n, giving an evidence that the complexity of sub-Riemannian geodesics increases with the step.
Occlusion-based estimation of independent multinomial random variables using occurrence and sequential information
2017
Abstract This paper deals with the relatively new field of sequence-based estimation in which the goal is to estimate the parameters of a distribution by utilizing both the information in the observations and in their sequence of appearance. Traditionally, the Maximum Likelihood (ML) and Bayesian estimation paradigms work within the model that the data, from which the parameters are to be estimated, is known, and that it is treated as a set rather than as a sequence. The position that we take is that these methods ignore, and thus discard, valuable sequence -based information, and our intention is to obtain ML estimates by “extracting” the information contained in the observations when perc…
Recent developments in flow-analysis vibrational spectroscopy
2007
Abstract This review deals with developments in the new century on the use of vibrational spectroscopy techniques for detection in flow-injection analysis (FIA) systems. To provide a picture of the evolution, highlights and future developments in this field, we revisited Fourier transform infrared (FTIR), in the mid-IR and near-IR ranges, and FT-Raman spectrometry applications using different approaches, from classical FIA to modern (sequential injection analysis (SIA) or multicommutation). We used the analytical abstracts database for 2000–06 for the literature search, but we based this review very much on the experience of our team in this field.
Guest Editorial Special Section on Recent Trends and Developments in Industry 4.0 Motivated Robotic Solutions
2018
The twelve papers in this special section focus on the development of robotic solutions for smart factories in industry - the concept of the fourth industrial revolution (industry 4.0). The inclusion of robotics is expected to deeply change the future manufacturing and production processes, and lead to smart factories that will benefit from the main design principles of Industry 4.0: interoperability, virtualization, decentralization, real-time capability, service orientation, and modularity. Robotics will have a key role in this development since innovative technologies and solutions, traditionally associated with the service robotics sector, are going to migrate to industrial smarter robo…
A Study on Distributed Fault-Tolerant Service Architectures for Critical Software Systems
2021
Reliable systems have been the subject of much research in the past years, with societal dependency on computer systems becoming more and more apparent. With more and more organizations embracing DevOps culture, there is a persistent need to understand how these systems are built and what their trade-offs are. This paper discusses and benchmarks the components of a modern fault tolerant and easily scalable system, designed to maximize up-time. The paper also describes the techniques used in the development of such a system. The system architecture described is implemented through several services deployed for a new critical single sign-on system deployed at CERN (The European Laboratory for…
Issues in Software Inspection Practices
2005
The motivation for this research comes from a need to improve software inspection practices in software organizations. Even if inspections are well defined and regularly used in an organization, there may be some problems which can greatly reduce inspection effectiveness. The paper presents a list of inspection related problems which are known in the literature. It also relates some experiences from two case organizations. In addition, this paper provides an approach which helps identifying problems of this kind and directing limited improvement resources effectively.