Search results for "Civil Engineering"
showing 10 items of 1216 documents
Aspects regarding the appreciation of regularity and punctuality in the public transport system from Sibiu, Romania
2021
Regularity and punctuality are two very important measures for evaluating the quality of a public transport system. Several indicators can be used to estimate them, each with advantages and disadvantages. The paper comparatively describes a series of such indicators and presents a study conducted for two public transport lines in Sibiu, Romania. The study shows how, depending on the indicators used, the results show the influence of different factors.
Splitting Magnitude Response into Real and Imaginary Parts
2017
The determination of real and imaginary parts from magnitude responses is studied for causal linear time-invariant systems having monotonic impulse responses. It is demonstrated that the problem can be interpreted as a special filtering task in the Mellin transform domain having a diffuse magnitude response bounded by the magnitude responses of the filters corresponding to zero and maximum imaginary parts prescribed by the Kronig-Kramers relations. Discrete-time filters processing geometrically sampled magnitude responses are designed for determining the real and imaginary parts. Testing results are presented verifying the performance of the filters.
The improvement of quality management system in a porcelain factory
2019
According to SR EN ISO 9000:2015, quality management system can be considered “a set of Policies, Procedures, Processes and resources used to achieve the organization objectives and desired results, by manages the interacting processes, resources required and inter-related parts of the business”. The requirements of a quality management system that need to be implemented by companies in order to produce high quality products and to achieve continual improvement are described in ISO 9001. The aim of this research is to improve the quality management system implemented in a porcelain factory, named S.C. APULUM S.A. The implementation of ISO 9001:2015 in the organization involves monitoring pr…
Capability studies, helpful tools in process quality improvement
2017
Ability of processes to meet customer’quality requirements has become essential for providing competitive advantages such as cost savings, reducing the number of nonconfoming products or increasing customer satisfaction. This paper aims to conduct a capability study for a swaging process (that ensures an assembly dimension) of a key product characteristic (the outer diameter of a new part), related to the concept of capability and performance indices and how these metrics can be used and interpreted to become powerful tools for decision making. To achieve the goal of the paper, the following key aspects were analyzed: capability of the measurement system capability (gage R&R), production eq…
Assessment of process stability and capability in a manufacturing organization: a case study
2021
Quality is considered asthe principal factor that determines the long-termsuccess or failure of any organization. Organizations perform quality control by monitoring process output using Statistical Quality Control, performed as part of the production process (Statistical Process Control, SPC) or as a final quality control check (Acceptance Sampling).SPC is a major quality management statistical tool and its instruments (control charts and capability analysis) are applied to virtually any type of organization (manufacturing, services or transactions - for example, those involving data, communications, software, or movement of materials). The aim of this paper is to present a case study, rea…
Toward a holistic environmental impact assessment of marble quarrying and processing: proposal of a novel easy-to-use IPAT-based method.
2016
Marble is a natural dimension stone that is widely used in building due to its resistance and esthetic qualities. Unfortunately, some concerns have arisen regarding its production process because quarrying and processing activities demand significant amounts of energy and greatly affect the environment. Further, performing an environmental analysis of a production process such as that of marble requires the consideration of many environmental aspects (e.g., noise, vibrations, dust and waste production, energy consumption). Unfortunately, the current impact accounting tools do not seem to be capable of considering all of the major aspects of the (marble) production process that may affect th…
Infection risks of city canal swimming events in the Netherlands in 2016.
2018
Introduction Swimming events in city canals are gaining popularity in the Netherlands, even though canal water is usually not officially designated for recreational use. Knowledge regarding the risk of infection after swimming in canals is limited. An outbreak was reported in 2015 following a canal swimming event in Utrecht, the Netherlands. Local governments were concerned about the health risks of such events. In order to assess the safety of canal swimming, the Public Health Service (PHS) prospectively investigated two city canal swimming events in 2015. In 2016, we repeated this study, aiming to prospectively determine the risks of infection during two urban swimming events, the Utrecht…
From Buildings' End of Life to Aggregate Recycling under a Circular Economic Perspective: A Comparative Life Cycle Assessment Case Study
2021
The demolition of buildings, apart from being energy intensive and disruptive, inevitably produces construction and demolition waste (C&Dw). Unfortunately, even today, the majority of this waste ends up underexploited and not considered as valuable resources to be re-circulated into a closed/open loop process under the umbrella of circular economy (CE). Considering the amount of virgin aggregates needed in civil engineering applications, C&Dw can act as sustainable catalyst towards the preservation of natural resources and the shift towards a CE. This study completes current research by presenting a life cycle inventory compilation and life cycle assessment case study of two buildin…
Performance assessment of PPP surveys with open source software using the GNSS GPS-GLONASS-Galileo constellations
2020
In this work, the performance of the multi-GNSS (Global Navigation Satellite System) Precise Point Positioning (PPP) technique, in static mode, is analyzed. Specifically, GPS (Global Positioning System), GLONASS, and Galileo systems are considered, and quantifying the Galileo contribution is one of the main objectives. The open source software RTKLib is adopted to process the data, with precise satellite orbits and clocks from CNES (Centre National d&rsquo
Simultaneous retrieval of global scale Vegetation Optical Depth, surface roughness, and soil moisture using X-band AMSR-E observations
2019
Abstract The radiative transfer scheme implemented for the retrieval of soil moisture from passive microwaves is a function of scattering, polarization mixing and attenuation effects of soil and vegetation. Theses factors are usually represented by Vegetation Optical Depth (VOD), vegetation scattering albedo, and surface roughness parameter, along with soil moisture. The VOD is the degree to which vegetation attenuates the microwave radiation. It has generally the dominant effect from vegetation, whereas scattering is negligible and close to zero. The surface roughness (which varies in space but not much in time) is until recently, often assumed to be a global constant. In this work, we att…