| 1. |
- Andersson, Magnus, et al.
(författare)
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Inscribing Interpretive Flexibility of Context Data in Ubiquitous Computing Environments: An Action Research Study of Vertical Standard Development
- 2009
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Ingår i: International Journal of Advanced Pervasive and Ubiquitous Computing. - : IGI Global. - 1937-965X .- 1937-9668. ; 1:2, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Ubiquitous computing environments grant organizations a multitude of dynamic context data emanating from embedded and mobile components. Such data may enhance organizations’ understanding of the different contexts in which they act. However, extant IS literature indicates that the utility of context data is frequently hampered by a priori interpretations of context embodied within the acquiring technologies themselves. Building on a 5-year canonical action research study within the Swedish transport industry, this paper reports an attempt to shift the locus of interpretation of context data by rearranging an assemblage of embedded, mobile, and stationary technologies. This was done by developing a vertical standard as a means to inscribe interpretive flexibility of context data. With the objective to extend the current understanding of how to enable cross-organizational access to reinterpretable context data, the paper contributes with an analysis of existing design requirements for context-aware ecosystems. This analysis reveals the complexity of accomplishing collaborative linkages between socio-technical elements in ubiquitous computing environments, and highlights important implications for research and practice.
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| 2. |
- Andersson, Roy
(författare)
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Supply chain resilience through quality management
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The length and complexity of the supply chain tend to increase, rather than diminish, thereby making the supply chain riskier and less predictable and, hence, more vulnerable. At the same time, customers are becoming increasingly demanding. The challenge to businesses today is to create a resilient supply chain in order to manage and mitigate risk and vulnerability.The purpose of the thesis is to explore, describe and develop the use of a combined quality management philosophy in logistics processes in order to improve supply chain resilience. The findings are supported by six studies, which are presented here in six papers.The studies show that there is a lot to gain if organisations are able to combine quality management philosophies, as they are complementary to one another. TQM places its strongest emphasis on the commitment and involvement of all employees. Lean is a discipline that focuses on process speed and removal of waste in order to increase customer value. Six Sigma benefits from an added focus on variability and design of products/services and processes. It has been indicated that a combined quality management philosophy makes the logistics processes more reliable, flexible, agile and robust while reducing cost. The companies’ risk awareness has increased and their risk management has been improved, thanks to the Six Sigma training programmes and philosophy. Using a combined quality management philosophy, the speed of production could be increased, and the responsiveness and flexibility could be improved, which means quicker response to changes. It has also been indicated that a combined quality management philosophy improves the companies’ resilience, due to their increased agility and strengthened ability to handle variability and risk management. Quality management tools can be very effective in the companies’ efforts to control supply chain risk and to identify risk sources of variation, even outside the focal company. In Six Sigma projects, the root cause of variation is often found outside the focal companies, which requires more collaboration in the supply chain. However, if the companies that use a combined quality management philosophy intend to become more resilient, they must involve suppliers and customers more in their own processes and design products/services and processes together.Collaboration with the suppliers and customers and the notion of how to extend a combined quality management philosophy outside the focal company are of importance in order to make the whole supply chain resilient. This could lead to a problem, especially since the conditions for transport and logistics in regards to the application of quality methods and tools represent a large area, unexploited by the companies. On the other hand, Six Sigma has standardised training courses, and it has been demonstrated how a Six Sigma framework can enable collaboration across companies’ boundaries in the supply chain, with the use of Six Sigma training and the DMAIC-roadmap as a common platform. Even if a combined quality management philosophy is effective and efficient, the companies must re-invest in additional methods, tools and strategies to make the entire supply chain resilient. It could be this re-investment in risk prevention and mitigation solutions that enables faster process responsiveness, the establishment of a risk management culture by creating common values, culture and rules in the supply chain and the use of logistics strategies and methods.
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| 3. |
- Axelberg, Peter G.V., et al.
(författare)
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Performance Tests of a Support Vector Machine used for Classification of Voltage Disturbances
- 2006
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Ingår i: in proc. of 12th International conf. on Harmonics and Quality of Power (ICHQP 2006), Cascais, Portugal, Oct.1-5, 2006.
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a novel method for classifying voltage disturbances in electric power systems by using the Support Vector Machine (SVM) method. The proposed SVM classifier is designed to classify five common types of voltage disturbances and experiments have been conducted on recorded disturbances with good classification results. The proposed SVM classifier is also shown to be robust in terms of using training data and testing data that originate from two different power networks.
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| 4. |
- Axelberg, Peter
(författare)
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On Tracing Flicker Sources and Classification of Voltage Disturbances
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Developments in measurement technology, communication and data storage have resulted in measurement systems that produce large amount of data. Together with the long existing need for characterizing the performance of the power system this has resulted in demand for automatic and efficient information-extraction methods. The objective of the research work presented in this thesis was therefore to develop new robust methods that extract additional information from voltage and current measurements in power systems. This work has contributed to two specific areas of interest. The first part of the work has been the development of a measurement method that gives information how voltage flicker propagates (with respect to a monitoring point) and how to trace a flicker source. As part of this work the quantity of flicker power has been defined and integrated in a perceptionally relevant measurement method. The method has been validated by theoretical analysis, by simulations, and by two field tests (at low-voltage and at 130-kV level) with results that matched the theory. The conclusion of this part of the work is that flicker power can be used for efficient tracing of a flicker source and to determine how flicker propagates. The second part of the work has been the development of a voltage disturbance classification system based on the statistical learning theory-based Support Vector Machine method. The classification system shows always high classification accuracy when training data and test data originate from the same source. High classification accuracy is also obtained when training data originate from one power network and test data from another. The classification system shows, however, lower performance when training data is synthetic and test data originate from real power networks. It was concluded that it is possible to develop a classification system based on the Support Vector Machine method with “global settings” that can be used at any location without the need to retrain. The conclusion is that the proposed classification system works well and shows sufficiently high classification accuracy when trained on data that originate from real disturbances. However, more research activities are needed in order to generate synthetic data that have statistical characteristics close enough to real disturbances to replace actual recordings as training data.
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| 5. |
- Axelsson, Ann-Sofie, et al.
(författare)
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Att etablera ett kollaboratorium inom biblioteks- och informationsvetenskap : behov och utmaningar från ett praktikerperspektiv
- 2007
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Ingår i: Svensk biblioteksforskning. - : Högskolan i Borås. - 0284-4354 .- 1653-5235. ; 16:1, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- This article describes a study that investigated the need for and challenges connected to the establishment of a collaboratory - a sociotechnical forum where information and other resources can be made accessible and used by practitioners within library and information science. In order to identify needs and challenges interviews were carried out with a number of practitioners at a number of different institutions. The results reveal that there is a need for a collaboratory in order to facilitate the sharing of personal knowledge “on demand”. It is of great importance that the collaboratory is well integrated with practitioner’s daily activities.
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| 6. |
- Ayllon, David, et al.
(författare)
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Cole equation and parameter estimation from electrical bioimpedance spectroscopy measurements : A comparative study
- 2009
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Ingår i: EMBC. - Buenos Aires : IEEE Engineering in Medicine and Biology. ; , s. 3779-3782, s. 3779-3782
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Konferensbidrag (refereegranskat)abstract
- Since there are several applications of Electrical Bioimpedance (EBI) that use the Cole parameters as base of the analysis, to fit EBI measured data onto the Cole equation is a very common practice within Multifrequency-EBI and spectroscopy. The aim of this paper is to compare different fitting methods for EBI data in order to evaluate their suitability to fit the Cole equation and estimate the Cole parameters. Three of the studied fittings are based on the use of Non-Linear Least Squares on the Cole model, one using the real part only, a second using the imaginary part and the third using the complex impedance. Furthermore, a novel fitting method done on the impedance plane, without using any frequency information has been implemented and included in the comparison. Results show that the four methods perform relatively well but the best fitting in terms of standard error of estimate is the fitting obtained from the resistance only. The results support the possibility of measuring only the resistive part of the bioimpedance to accurately fit Cole equation and estimate the Cole parameters, with entailed advantages.
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| 7. |
- Bengtsson, Magnus, et al.
(författare)
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Improving yield and shape in a crushing plant
- 2009
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Ingår i: Minerals Engineering. - : Elsevier BV. - 0892-6875 .- 1872-9444. ; 22:7-8, s. 618-624
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Tidskriftsartikel (refereegranskat)abstract
- There is increasing demand to optimise yield and increase capacity of crushing plants. Research in this area has resulted in the development of numerous optimisation tools, and resent research has shown that the economic aspects of production have great influence on the optimisation results. The profitability of a product is influenced by several parameters, and control of all these parameters is necessary to use some sort of optimisation software. In this paper, we present a case study of a typical crushing plant, with the goal of reducing the number of crusher while keeping the plant capacity and quality. By reducing the number of crusher the plant will need less maintenance which will decrease the operating costs. The article presents a method to combine crushing plant simulation and optimisation with quality and economic considerations in order to successfully study alternative configurations of the plant.
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| 8. |
- Bengtsson, Magnus, 1973, et al.
(författare)
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Improving Yield and Shape in a Crushing Plant
- 2009
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Ingår i: Proceedings of 12th European Symposium on Comminution and Classification (ESCC2009).
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Konferensbidrag (refereegranskat)abstract
- There is increasing demand to optimise yield and increase capacity of crushing plants. Research in this area has resulted in the development of numerous optimisation tools, and resent research has shown that the quality aspects of production have great influence on the optimisation results. The quality and capacity of a product is influenced by several parameters, and in order to control all these parameters it is necessary to use some sort of optimisation software. In this paper, a novel approach to analyse parameters influence on product capacity and quality is presented. As an example a cone crusher and a vertical shaft impact crusher (VSI) is simulated in a tertiary stage. The simulation shows how capacity and product quality for a range of products will be affected when a parameter is changed. The paper also shows how wear will affect product capacity and quality.
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| 9. |
- Bengtsson, Magnus, et al.
(författare)
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Measuring characteristics of aggregate material from vertical shaft impact crushers
- 2006
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Ingår i: Minerals Engineering. - : Elsevier BV. - 0892-6875 .- 1872-9444. ; 19:15, s. 1479-1486
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Tidskriftsartikel (refereegranskat)abstract
- Natural gravel has traditionally been the main choice of material for Swedish concrete manufacturers. However, due to the fact that natural gravel also acts as a fresh water filter, the deposits are limited. The obvious question is how to compare machine made and natural gravel in terms of particle shape, rheology and other material characteristics. This paper will present some methods and results that demonstrate performance of different machine made rock materials. Particle shape characteristics were assessed from flow measurements in a standard cone. The vertical shaft impact crusher (VSI) produces gravel that is a good alternative to natural gravel. The quality of the material and the particle shape seem to meet concrete producers’ demands.
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| 10. |
- Bengtsson, Magnus, 1973, et al.
(författare)
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Modelling of output and power consumption in vertical shaft impact crushers
- 2008
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Ingår i: International Journal of Mineral Processing. - : Elsevier BV. - 0301-7516 .- 1879-3525. ; 88:1-2, s. 18-23
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Tidskriftsartikel (refereegranskat)abstract
- The vertical shaft impact (VSI) crusher is a commonly-used machine in aggregate production. A comprehensive understanding of the physical phenomena that influence the power consumption and the particle output of the device are essential to enable development of protocols that minimize energy consumption during rock crushing.While natural gravel has traditionally been the main choice of material for Swedish concrete manufacturers, the number of deposits is limited due to its role as a fresh water filter. It is therefore essential to achieve a product size distribution of aggregate that is on the same order as that of natural gravel to enable its use in concrete production.This work aims to present a model that predicts capacity, power and particle size distribution in a VSI crusher.
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