454 research outputs found
Theory of constraints (TOC) production and manufacturing performance
This paper is based on an empirical study of the relationship between Theory of Constraints (TOC) production and operational performance in manufacturing plants. The study uses a survey questionnaire to collect data from a sample of 61 European firms which have implemented the TOC approach. Analysis of variance (ANOVA) technique and regression models have been employed to test the research hypotheses. The results detect many differences and similarities in adoption of TOC practices across the countries and suggest that manufacturing managers should consider adopting some TOC practices instead of others. In particular the Drum-buffer-rope methodology, the development of a Master Production Schedule based on constraints and the use of Non-constraint resources with excess capacity are among the most important practices to enhance competitive performance of manufacturing plants
Service Implementation Framework in Manufacturing Firms: A Case Study
The culture and the operational methods of service management have become a formidable competitive weapon even for manufacturing firms. The term "service factory" has been proposed for identifying that particular integration of products and services, achieved by the excellent manufacturing firm, where "service is a multidimensional concept". The creation of a service factory necessarily implies a radical change in the operational and organizational characteristics of the firm. In order to support manufacturing firms in adopting a service strategy, it is relevant on the one hand to identify the bundle of services which have to be provided for the customers and, on the other hand, to understand the implications for firm management model. As regards the first point, the paper proposes a framework which classifies the services along with two dimensions: Timedimension and target-dimension. The proposed framework is of interest for manufacturing firms because it allows a better recognition of services that are more perceptible for the customers. In the second part of the paper, authors discuss the implications of a service strategy adoption on the management model of manufacturing firms. In order to carry out this analysis, authors propose a model that combines four service dimensions with three decision-making categories (Organization, Methodologies and Technologies). In the end, the proposed framework has been applied in a sample of Italian hot water heater manufacturers and a case study analysis has been carried out
Enablers and Constraints in Implementing Lean Manufacturing: evidence from Brazilian SMEs
Lean Manufacturing has revolutionized the global manufacturing environment at an unprecedented rate. In scholarly and managerial literature, many works have reported that Lean Manufacturing is a very efficient approach and a straightforward way towards process improvements, in terms of productivity and value adding activities ratio. However, many studies on Lean Manufacturing have highlighted many problems in its implementation. The analysis carried out within the research project is aimed to the factors enabling or constraining the Lean Transformation of a firm’s production system, along with the most relevant tools or practices to be applied. The research methodology used is the so-called “Normative Delphi” with a panel formed by 32 experts coming from 16 Brazilian SMEs. Our results are partially consistent with what has already been discussed in the literature and we found that the most relevant tools/practices are: value stream mapping, 5S methodology, and Kaizen (Gemba walks); the top three enabling factors are: knowledge and sponsorship of senior management, focus on continuous improvement, and employee development fostered by the company; finally, the main critical constraints are: little support from the top management, resistance to change by middle management, and poor or non-qualified Lean training activities
Piccolo Mondo by Fanny Romagnoli and Silvia Albertoni: a study on production, circulation, materiality and content (1901-1938)
Entre as últimas duas décadas do século XIX e as três primeiras do XX é possível encontrar indícios de distribuição e circulação de livros italianos entre os imigrantes e seus descendentes. Este artigo objetiva compreender a produção e a circulação dos livros de leitura de Fanny Romagnoli e Silvia Albertoni, autoras de Piccolo Mondo, aprovados para serem adotados nas escolas elementares da Península e escolas italianas no Brasil no início do século XX e, em seguida, analisar um dos volumes, o Sillabario, destinado ao uso da primeira classe. Ancorado nas contribuições da História da Educação e na História Cultural e tendo a análise documental como procedimento adotado, o presente texto toma como fonte privilegiada os livros de leitura Piccolo Mondo, além de circulares ministeriais, dicionário biobibliográfico e jornais. Opera ainda com a categoria transnacional como uma abordagem metodológica na História da Educação. Os livros são considerados artefatos culturais que se situam na articulação entre as prescrições impostas pelos programas oficiais e os discursos singulares dos professores. Para o processo de internalização da ideia de nação italiana se fez necessário um projeto político-pedagógico capaz de reunir as noções de nação, Estado e educação moral em um único processo virtuoso. Pode-se afirmar que Piccolo Mondo aderiu ao projeto de criar um “homem novo”, cidadão de um Estado capaz de conduzir a nação à conquista da modernidade
A novel framework for the use of workflow system in the integration of supply chain tiers
The global competition has imposed challenges to supply chain integration, mainly, during the process of obtain information to make demand management decisions. This paper proposes an integrated framework for data collection, analysis and results dissemination in the supply chain management (SCM), contributing to research and alternatives for \u201cThe Bullwhip Effect\u201d issue. In this sense, it is necessary to discuss the integration of supply chain management, Enterprise Resources Planning (ERP) functionality and others systems, to enlarge this scope to the total supply chain players. The ERP web-based tool and Workflow Systems (WS) can contribute to solve issues related to supply chain management. Starting from a detailed analysis of the research background regarding current SCM definitions and integration problems, Information Technology and Communication (ITC) development and WS in order to map and ensure flow fluency; the paper proposes a model to increase the overall integrations and an application in a case study for supporting the decisions that are aligned with the company\u2019s strategic objectives. This paper is divided in: research background; proposed model of the SC integration; case study, conclusions and future research
Modelling of natural gas sweetening and dehydration processes
Two key steps involved in the natural gas production are the sweetening (via chemical absorption) and the dehydration (either via physical absorption or via adsorption on solid dessicants). In this thesis these processes are modelled using the gPROMS ProcessBuilder process simulator.ope
Comparative analysis of TMS-EEG signal using different approaches in healthy subjects
openThe integration of transcranial magnetic stimulation with electroencephalography (TMS-EEG) represents a useful non-invasive approach to assess cortical excitability, plasticity and intra-cortical connectivity in humans in physiological and pathological conditions.
However, biological and environmental noise sources can contaminate the TMS-evoked potentials (TEPs). Therefore, signal preprocessing represents a fundamental step in the analysis of these potentials and is critical to remove artefactual components while preserving the physiological brain activity.
The objective of the present study is to evaluate the effects of different signal processing pipelines, (namely Leodori et al., Rogasch et al., Mutanen et al.) applied on TEPs recorded in five healthy volunteers after TMS stimulation of the primary motor cortex (M1) of the dominant hemisphere. These pipelines were used and compared to remove artifacts and improve the quality of the recorded signals, laying the foundation for subsequent analyses. Various algorithms, such as Independent Component Analysis (ICA), SOUND, and SSP-SIR, were used in each pipeline.
Furthermore, after signal preprocessing, current localization was performed to map the TMS-induced neural activation in the cortex. This methodology provided valuable information on the spatial distribution of activity and further validated the effectiveness of the signal cleaning pipelines.
Comparing the effects of the different pipelines on the same dataset, we observed considerable variability in how the pipelines affect various signal characteristics. We observed significant differences in the effects on signal amplitude and in the identification and characterisation of peaks of interest, i.e., P30, N45, P60, N100, P180. The identification and characteristics of these peaks showed variability, especially with regard to the early peaks, which reflect the cortical excitability of the stimulated area and are the more affected by biological and stimulation-related artifacts.
Despite these differences, the topographies and source localisation, which are the most informative and useful in reconstructing signal dynamics, were consistent and reliable between the different pipelines considered.
The results suggest that the existing methodologies for analysing TEPs produce different effects on the data, but are all capable of reproducing the dynamics of the signal and its components. Future studies evaluating different signal preprocessing methods in larger populations are needed to determine an appropriate workflow that can be shared through the scientific community, in order to make the results obtained in different centres comparable
Biomechanical comparison of shorts with different pads: An Insight into the Perineum Protection Issue
An intensive use of the bicycle may increase the risk of erectile dysfunction and the compression of the perineal area has been showed to be a major mechanism leading to sexual alterations compromising the quality of life. Manufacturers claim that pads contribute to increase cyclists perineal protection ensuring a high level of comfort. To investigate the influence of various cycling pads with regard to perineal protection and level of comfort. Nine club road cyclists rode 20 min on a drum simulator, located at the Nutrition and Exercise Physiology Laboratory, at a constant speed and gear ratio wearing the shorts with 3 cycling pads of different design and thickness: basic (BAS), intermediate (INT), and endurance (END). Kinematics and pressure data were recorded at min 5, 15, and 20 of the test using a motion capture system and a pressure sensor mat. The variables of interest were: 3-dimensional pelvis excursions, peak pressure, mean pressure, and vertical force. The comfort level was assessed with a ranking order based on the subjects' perception after the 20-min trials and measuring the vertical ground reaction force under the anterior wheel as well as the length of the center of pressure (COP) trajectory on the saddle. Results showed that the vertical force and the average value of mean pressure on the saddle significantly decreased during the 20-min period of testing for BAS and END. Mean peak pressure on the corresponding perineal cyclist area significantly increased only for BAS during the 20-min period. Interestingly objective comfort indexes measured did not match cyclists subjective comfort evaluation. The lower capacity of BAS to reduce the peak pressure on the corresponding perineal area after 20 min of testing, together with its positive comfort evaluation, suggest that a balance between protection and perceived comfort should be taken into account in the choice of the pad. Hence, the quantitative approach of objective comfort indexes introduced in this study could be helpful for manufacturers in the development of their protective pads
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