1,113 research outputs found
Sensor Fused Indoor Positioning Using Dual Band WiFi Signal Measurements
A ubiquitous and accurate positioning system for mobile devices is of great importance both to business and research due to the large number of applications and services it enables. In most outdoor environments this problem was solved by the introduction of the Global Positioning System (GPS). In indoor or suburban areas however, the GPS signals are often too weak to enable a reliable position estimate. Instead, other techniques must be utilized to provide accurate positioning. One of these is trilateration based on WiFi signal strengths. This is an auspicious technology to use partly because of the large number of access points (APs) in our everyday environment, and partly due to the possibility of measuring signal strength with a normal smartphone. The technique is further enabled by the move to include transmitters at 2.4 as well as 5 GHz in modern APs, providing a better basis for accurate position estimations. Furthermore, the motion sensors present in today’s smartphones are accurate enough to provide a short-time estimate of the user’s movement with high accuracy. In this thesis, both of these technologies are used to develop an accurate method for indoor positioning, and the contributions can be summed up into two points. The first contribution is an investigation of the behavior of two WiFi frequencies, 2.4 and 5 GHz, where their time dependent noise is proven to be almost uncorrelated with each other. This is then exploited to develop aWiFi-only trilateration algorithm by the use of a particle filter (PF), where the only restriction is that the locations of the APs need to be known. The second contribution is adding an accelerometer and a gyroscope to the algorithm, to provide a more accurate estimation. A step counter is developed using the accelerometer, and the gyroscope detects changes in heading while the WiFi signal strengths give information about the position. This makes it possible to alongside the position also estimate both heading and step length, while still keeping the only restriction of knowing the AP locations. The resulting algorithm produces position estimates with a mean error less than two meters for a specific use case, and around three meters when a more lenient user behavior is allowed
Epidemiological and experimental studies on sarcoma with focus on gastrointestinal stromal tumors
Sarcoma is the common denominator for malignant tumors of mesenchymal origin. Sarcomas encompass almost 100 diagnoses with different histology, molecular features and natural history, and may present in any part of the body. The most common sarcoma in the abdomen is the gastrointestinal stromal tumor (GIST). GIST is most frequent in the stomach followed by the small intestine, yet can occur throughout the gastrointestinal tract. The first line of treatment for GIST is complete surgical resection, if feasible. Since the discovery of targeted small-molecule therapy with imatinib in 1998 and the successful treatment of the first GIST patient two years later, this therapy has attracted much attention and GIST has become a model system for modern oncological treatment. This thesis is based on translational research in the field of sarcoma with the main focus on GIST.
In paper I, a proof-ofconcept study of intracellular imatinib measurements is presented. Cell-cultures of imatinib-sensitive and resistant cells were exposed to imatinib in different concentrations. The analysis was performed with liquid chromatography mass spectrometry and time-of-flight detection (LC/MS-TOF). The imatinib-resistant cellline had significantly lower imatinib concentrations. Clinical samples from three patients were analyzed using the same protocol and showed imatinib accumulation in tissue and a large variability between patients.
In paper II, the importance of surgical technique and surgical margins was studied. Resecting GIST with a wide margin of >2 cm normal tissue and intact covering peritoneum, lead to improved recurrence-free survival. The impact of the margin was independent when adjusting for other known risk factors such as size, site and mitotic index.
Paper III analyzed an expanded cohort of imatinib treated and resected GIST using an improved, updated protocol for mass spectrometry and drug transporter expression analysis. The previous finding of large intra- and interpatient variability of imatinib concentrations was confirmed. Plasma and tissue concentrations were not correlated to the response. Low expression of drug transport proteins was correlated to the improved histological response.
Finally, paper IV is a nested case-control study and describes trends in breast sarcoma incidence in Sweden during the period of 1993- 2003, showing a 4-fold increase of angiosarcoma. The angiosarcoma patients were overrepresented as carrying a history of breast cancer with the highest risk 5-10 years after their breast cancer diagnosis (OR 167, CI 95% 35.1-791; p<0.001). This points to the possibility that the increased use of radiotherapy could be a reason for a rise in incidence of angiosarcoma
Sensor Fused Indoor Positioning Using Dual Band WiFi Signal Measurements
In this paper, signal strengths from known WiFi access points are used together with a particle filter to perform indoor navigation. It is shown that more information is obtained by using signals of both 2.4 and 5.0 GHz, compared to using only one frequency. Thus, using both frequencies provides a more accurate positioning. The second contribution is an algorithm where WiFi measurements are combined with pedestrian dead reckoning (PDR), which is based on step counting using an accelerometer and hypotheses of the heading using a gyroscope. This was found to provide further accuracy compared to more conventional methods
Method Engineering as Design Science
In this paper, we motivate, devise, demonstrate, and evaluate an approach for the research-based development of information systems development methods (ISDMs). This approach, termed “method engineering as design science” (ME-DS), emerged from the identified need for scholars to develop ISDMs using proper research methods that meet the standards of both rigor and relevance. ISDMs occupy a position of central importance to information systems development and scholars have therefore invested extensive resources over the years in developing such methods. The method engineering (ME) discipline has developed different frameworks and methods to guide such development work and, for that purpose, they are well-suited. Still, there remains a need for applications and evaluations of ISDMs based on the demands for knowledge justification. Unfortunately, in many cases, scholars come up short with regard to how ISDMs are generated and empirically validated. While design science (DS) stresses knowledge justification, prominent DS approaches seem to be biased toward the development of IT artifacts, making this approach ill-suited for the development of method artifacts. We therefore propose eight principles that marry ME and DS, resulting in a process model with six activities to support research-based development of ISDMs. We demonstrate and evaluate ME-DS by assessing three existing research papers that propose ISDMs. These retrospectives show how ME-DS directs attention to certain aspects of the research process and provides support for future ISDM development
Evaluating End User Development as a Requirements Engineering Technique for Communicating Across Social Worlds During Systems Development
Requirements engineering is a key activity in systems development. This paper examines six systems development projects that have used end user development (EUD) as a requirements engineering technique for communicating across social worlds. For this purpose, we employed the theoretical lens of design boundary object in order to focus on functional and political ecologies during the development process. Four features were investigated: (1) the capability for common representation, (2) the capability to transform design knowledge, (3) the capability to mobilise for design action, and (4) the capability to legitimise design knowledge across social worlds. We concluded that EUD means a high degree of end user involvement and takes advantage of end users’ know-how. It has the ability to capture requirements and transfer them into the final information system without the need to make an explicit design rationale available to the systems developers. However, systems developers have little or no influence on business requirements. Their role is mainly as technical experts rather than business developers. The systems developers took control and power of technical requirements, while requirements that relate to business logic remained with the end users. Consequently, the systems developers did not act as catalysts in the systems development process
Standardization of packages at Duni AB - A process to maintain a limitation of packages and increase the filling rate.
Duni AB is a leading provider of premium solutions and products, e.g. napkins, plates, table covers, candles and food solutions. The company has recently made major organizational changes, i.e. going from a decentralized organization to a centralized organization with all product development in Malmö. There is a lot of work to be done to optimize both product and packaging development in order to reduce logistics costs and enhance production efficiency. The filling rate among the napkin packages is at present low and the fact that the company has no process for introducing new packages for napkins, has caused a large number of different box sizes. The problem of finding appropriate packages for napkins is complex, since many factors affect the packaging size and design. The lack of standardization of the boxes causes consequences during transports, handling, production and purchasing. At present Duni have no process for introducing new boxes. For this reason, the purpose of the Master thesis was to develop a process to maintain a limitation of boxes and develop standardized boxes. During the Master thesis a systems approach has been used and information has been gathered through interviews, database searching, literature studies, simulations in software for pallet utalization and a visit at Duni`s plant in Bramsche, Germany. In the Master thesis a box management tool have been developed. The tool helps to examine if existing boxes can be used for new products and illustrates how adjustment in the number of packages per box affects the choice of an appropriate box. An inventory of Duni's existing packaging solutions (primary and secondary packaging) has been done and simulations have been carried out for each primary package, trying to find the most appropriate packaging solution, concerning filling rate. Duni have got an enhanced awareness of the packaging potential, as a way to increase sales and reduce cost associated with production and handling. The packaging function at Duni is nowadays involved at an early phase of the product development and there is still much work to be done, trying to reduce the amount of boxes and increase the filling rate of the boxes. By using the box management tool it is possible for Duni to take a further step in the process of making suitable packages for napkins
UNDERSTANDING BUSINESS EMPLOYEES\u27 CONDITIONS FOR PARTICIPATING IN PUBLIC E-SERVICE DEVELOPMENT
Today there is an increased interest in user participation in development of public e-services, since it is expected to bring similar value as it has done in other types of systems development. Existing research, however, has shown that introducing user participation to public e-service development is associated with a number of challenges. In this paper we have explored three user participation schools, Participatory Design, User Centered Design and User Innovation, with regard to two challenges: a) businesses employees current mandate and willingness to participate in public e-service development and b) business employees ability to participate in public e-service development. Our interview results show that businesses employees do have mandate to participate and also want to do so. Moreover, business employees ability to participate is high with respect to ICT knowledge but rather low with respect to knowledge regarding public authorities business processes. In addition, their knowledge about laws and regulations that affect public authorities is limited. Altogether, this limits the possibilities to apply user participation schools, such as User Innovation, which rely on a high degree of user-responsibility in identifying problems and solutions
Software developers reasoning behind adoption and use of software development methods – a systematic literature review
When adopting and using a Software Development Method (SDM), it is important to stay true to the philosophy of the method; otherwise, software developers might execute activities that do not lead to the intended outcomes. Currently, no overview of SDM research addresses software developers’ reasoning behind adopting and using SDMs. Accordingly, this paper aims to survey existing SDM research to scrutinize the current knowledge base on software developers’ type of reasoning behind SDM adoption and use. We executed a systematic literature review and analyzed existing research using two steps. First, we classified papers based on what type of reasoning was addressed regarding SDM adoption and use: rational, irrational, and non-rational. Second, we made a thematic synthesis across these three types of reasoning to provide a more detailed characterization of the existing research. We elicited 28 studies addressing software developers’ reasoning and identified five research themes. Building on these themes, we framed four future research directions with four broad research questions, which can be used as a basis for future research
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