| 1. |
- Stöggl, Thomas, et al.
(författare)
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Automatic classification of the Sub-Techniques (Gears) used in cross-country ski skating employing a mobile phone
- 2014
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 14:11, s. 20589-20601
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the current study was to develop and validate an automatic algorithm for classification of cross-country (XC) ski-skating gears (G) using Smartphone accelerometer data. Eleven XC skiers (seven men, four women) with regional-to-international levels of performance carried out roller skiing trials on a treadmill using fixed gears (G2left, G2right, G3, G4left, G4right) and a 950-m trial using different speeds and inclines, applying gears and sides as they normally would. Gear classification by the Smartphone (on the chest) and based on video recordings were compared. Formachine-learning, a collective database was compared to individual data. The Smartphone application identified the trials with fixed gears correctly in all cases. In the 950-m trial, participants executed 140 ± 22 cycles as assessed by video analysis, with the automatic Smartphone application giving a similar value. Based on collective data, gears were identified correctly 86.0% ± 8.9% of the time, a value that rose to 90.3% ± 4.1% (P < 0.01) with machine learning from individual data. Classification was most often incorrect during transition between gears, especially to or from G3. Identification was most often correct for skiers who made relatively few transitions between gears. The accuracy of the automatic procedure for identifying G2left, G2right, G3, G4left and G4right was 96%, 90%, 81%, 88% and 94%, respectively. The algorithm identified gears correctly 100% of the time when a single gear was used and 90% of the time when different gears were employed during a variable protocol. This algorithm could be improved with respect to identification of transitions between gears or the side employed within a given gear.
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| 2. |
- Andersson, Johan, et al.
(författare)
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A Framework for Analysis of Timing and Resource Utilization targeting Complex Embedded Systems
- 2006
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Ingår i: ARTES - A network for Real-Time research and graduate Education in Sweden 1997 - 2006. - Uppsala : Department of Information Technology. - 9150618598 ; , s. 297-329
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- A problem in common of many complex software systems embedded in industrialproducts is the absence of analyzability as formal models of the systembehavior does not exist. When performing maintenance of such systems it ishard to predict how changes will impact specific system properties related totiming and resource utilization and there is therefore a significant risk of runninginto problems with unexpected side-effects of the changes made, whichincreases development time required and costs.In this paper we present the ART Framework, a set of methods and toolsthat enable behavior impact analysis for existing industrial real-time systems.The ART Framework enables developers of complex software systems to identifyproblematic side-effects of a proposed design before vast resources havebeen invested in implementation and testing. This reduces the risk of expensiveand time-consuming problems discovered late in a development projectand also reduces the risk releasing software containing latent critical errors.
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| 3. |
- Andersson, Johan, et al.
(författare)
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Extracting Simulation Models from Complex Embedded Real-Time Systems
- 2006
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Ingår i: Proceedings of the 2006 International Conference on Software Engineering Advances, ICSEA'06, Tahiti, French Polynesia. - 0769527035 ; , s. Article number 4031792-
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Konferensbidrag (refereegranskat)abstract
- A modeling process is presented for extracting timingaccurate simulation models from complex embedded real-time systems. The process is supported by two complementary methods for tool-supported model extraction, Model Synthesis and Hybrid Model Extraction. The generated models enable impact analysis for complex real-time systems with respect to dynamic system properties, such as timing and resource usage. This can make software maintenance more predictable with respect to time-to-market and development costs, since timing errors can be identified early and avoided. The contribution of the paper is the modeling process, the Hybrid Model Extraction method and an interactive modeling tool, MASS, designed to support Hybrid Model Extraction of large implementations in C.
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| 4. |
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| 5. |
- Carlson, Jan, 1976-
(författare)
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Event Pattern Detection for Embedded Systems
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Events play an important role in many computer systems, from small reactive embedded applications to large distributed systems. Many applications react to events generated by a graphical user interface or by external sensors that monitor the system environment, and other systems use events for communication and synchronisation between independent subsystems. In some applications, however, individual event occurrences are not the main point of concern. Instead, the system should respond to certain event patterns, such as "the start button being pushed, followed by a temperature alarm within two seconds". One way to specify such event patterns is by means of an event algebra with operators for combining the simple events of a system into specifications of complex patterns.This thesis presents an event algebra with two important characteristics. First, it complies with a number of algebraic laws, which shows that the algebra operators behave as expected. Second, any pattern represented by an expression in this algebra can be efficiently detected with bounded resources in terms of memory and time, which is particularly important when event pattern detection is used in embedded systems, where resource efficiency and predictability are crucial.In addition to the formal algebra semantics and an efficient detection algorithm, the thesis describes how event pattern detection can be used in real-time systems without support from the underlying operating system, and presents schedulability theory for such systems. It also describes how the event algebra can be combined with a component model for embedded system, to support high level design of systems that react to event patterns.
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| 6. |
- Cedergren, Stefan, et al.
(författare)
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A Performance Evaluation Framework for Innovation a chapter in Innovation in Business and Enterprise: Technologies and Frameworks
- 2010
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Ingår i: Innovation in Business and Enterprise. - : IGI Global. - 9781615206438 ; , s. 135-149
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter presents a framework for a conceptual evaluation of the performance of industrial product innovation activities. The framework promotes a holistic view of performance by considering three categories of activities: Planning, Implementation, and Sales and Delivery. Successful performance evaluation comes from acknowledging the fact that there are different objectives for each of the three activity categories. Moreover, performance may be expressed as a function of the performance of the Planning, the Implementation, and the Sales and Delivery activities. In this chapter the results of research involving seven large companies in Sweden, with the objective of improving the understanding of what is required to be successful when developing complex industrial products, are presented. Key factors for success as well as some general conclusions are discussed.
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| 7. |
- Cedergren, Stefan, et al.
(författare)
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Challenges with Evaluating Performance in Product Development
- 2010. - 8
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Ingår i: 17TH INTERNATIONAL PRODUCT DEVELOPMENT MANAGEMENT CONFERENCE. - Murcia, Spain.
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Konferensbidrag (refereegranskat)abstract
- The purpose of this paper is to from a managerial perspective investigate performance evaluation practices in a product development context. The focus is on exploring how managers perceive and evaluate performance in a software-intensive product development context. The research approach pursued in this research consist of a literature review combined with focused group interviews and exploratory multiple case studies. Moreover, a number of seminars have been held to discuss the findings both in academia and in practice. The result of this research indicates that product development managers are dissatisfied with their current way of evaluating performance. Performance measurements and the perception of performance are focused on cost, time and quality, i.e. what is easily measurable and not necessarily what is important. The dimensions of value creations and learning are missing. It is argued that manager perception of performance is affected by how it is measured, hence limiting the scope of the performance criteria. Thus, a change in the way managers perceive performance is necessary before there can be any change in the way performance is evaluated. Managers within product development that are dissatisfied with their performance measurement system should focus on how the organization perceive performance. By developing relevant performance criteria the first step in developing an effective performance evaluation system is made.
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| 8. |
- Cedergren, Stefan, et al.
(författare)
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Evaluation of performance in a product development context
- 2010. - 4
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Ingår i: Business Horizons. - : Elsevier. - 0007-6813 .- 1873-6068. ; 53:4, s. 359-369
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Tidskriftsartikel (refereegranskat)abstract
- In today's competitive environment, the need is greater than ever to deploy product development investments more effectively. To assist managers, we have developed two conceptual tools to support the evaluation of performance in product development. The Performance Measurement Evaluation Matrix (PMEX) helps managers evaluate performance measurement systems they currently use, in order to identify areas requiring improvement. Results from using the PMEX indicate that it is common to associate performance measurements with the efficiency aspects of time, cost, and quality, without monitoring the value created. Performance is largely perceived by managers in terms of time, cost, and quality of the activities in the later phases of the development process. We contend that an effective performance measurement system is based on performance criteria, and then derives measurements based on these. It is argued that there should be a change in the perception of performance, before performance evaluation systems can be improved. The Product Development Organizational Performance Model (PDOPM) assists in developing the perception of performance by relating uncertainty, efficiency, and effectiveness at three generic activity levels within the product development function. The use of our tools provides an improved perception of performance and its measurement, thus enabling improvements to the evaluation of performance.
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| 9. |
- Cedergren, Stefan, 1978-
(författare)
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Performance in Product Development - The Case of Complex Products
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This research addresses the concept of performance in the development of complex products. More specifically, its aim is to study how performance is perceived and measured within large global companies, and how performance measurement systems can be designed in a systematic way. The exploratory results regard how performance is currently perceived and measured. It is argued that performance measurements are focused on the later stages of the development of complex products, thus making it difficult to perform changes during the development. The focus is on lagging rather than leading indicators of performance, hence it is concluded that focus is on reporting the result rather than the causes of the result. In line with these findings is the weak link between what managers perceive as success factors and what is measured, the perception of performance being influenced by what is measured, rather than the reverse. The prescriptive results focus on the development of models and frameworks to be used during the development of complex products. A general method for developing performance indicators is presented. The concept of Products in Development is proposed, this making it possible to monitor how value is created during the development of a product. Both these models aim at complementing the currently used performance measurement system in order to support effective and efficient development of complex products. The method used in this research is mainly focused around the collection of qualitative data through a focused group interview, multiple case studies,and industrial reference-group seminars. A survey has also been used to complement the qualitative with quantitative data. The use of various research methods has made it possible to triangulate the data, thus strengthening the validity of the findings.
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| 10. |
- Cedergren, Stefan, et al.
(författare)
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PMEX — A PERFORMANCE MEASUREMENT EVALUATION MATRIX FOR THE DEVELOPMENT OF INDUSTRIAL SOFTWARE-INTENSIVE PRODUCTS
- 2011. - 6
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Ingår i: International Journal of Innovation and Technology Management (IJITM). - : World Scientific Publishing. ; 8:1, s. 55-76
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Tidskriftsartikel (refereegranskat)abstract
- The ability to measure performance is both fundamental to and critical in successful product development. Previous research has focused on adding new measurements, not on evaluating those currently used. The performance measurement evaluation matrix (PMEX) is a tool to evaluate the performance-measurement system based on success factors in the development of software-intensive products. Three case studies have been conducted to test the PMEX and the results indicate that the PMEX enables managers to determine explicitly what is and what is not measured. Time, cost, and quality seem to be the focus of the performance measurements while technology and planning activities are absent.
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