| 1. |
- Haraldsson, E, et al.
(författare)
-
Endoscopic classification of the papilla of Vater. Results of an inter- and intraobserver agreement study
- 2017
-
Ingår i: United European Gastroenterology Journal. - : Wiley. - 2050-6406 .- 2050-6414. ; 5:4, s. 504-510
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Many endoscopists acknowledge that the appearance of the papilla of Vater seems to affect biliary cannulation. To assess the association between the macroscopic appearance of the papilla and biliary cannulation and other related clinical issues, a system is needed to define the appearance of the papilla. Objective: The purpose of this study was to validate an endoscopic classification of the papilla of Vater by assessing the interobserver and intraobserver agreements among endoscopist with varying experience. Methods: An endoscopic classification, based on pictures captured from 140 different papillae, containing four types of papillae was proposed. The four types are (a) Type 1: regular papilla, no distinctive features, ‘classic appearance’; (b) Type 2: small papilla, often flat, with a diameter ≤ 3 mm (approximately 9 Fr); (c) Type 3: protruding or pendulous papilla, a papilla that is standing out, protruding or bulging into the duodenal lumen or sometimes hanging down, pendulous with the orifice oriented caudally; and (d) Type 4: creased or ridged papilla, where the ductal mucosa seems to extend distally, rather out of the papillary orifice, either on a ridge or in a crease. To assess the level of interobserver agreement, a web-based survey was sent out to 18 endoscopists, containing 50 sets of still images of the papilla, distributed between the four different types. Three months later a follow-up survey, with images from the first survey was sent to the same endoscopists. Results: Interobserver agreement was substantial (κ = 0.62, 95% confidence interval (CI) 0.58–0.65) and were similar for both experts and non-experts. The intraobserver agreement assessed with the second survey was also substantial (κ = 0.66, 95% CI 0.59–0.72). Conclusion: The proposed endoscopic classification of the papilla of Vater seems to be easy to use, irrespective of the level of experience of the endoscopist. It carries a substantial inter- and intraobserver agreement and now the clinical relevance of the four different papilla types awaits to be determined.
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| 2. |
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| 3. |
- Aidemark, Lars-Göran, et al.
(författare)
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Management accounting in public and private hospitals: : a comparative study
- 2004
-
Ingår i: Studies in managerial and financial accounting. - 1479-3512. ; 14:5, s. 427-445
-
Tidskriftsartikel (refereegranskat)abstract
- This paper investigates whether hospitals run as limited companies have more cost conscious and organizationally committed clinic superintendents when compared with public hospitals. Also, if the management accounting systems differ in the hospitals studied. Using a questionnaire, two hospital companies are compared with two hospitals controlled by political boards. According to the analysis there are no significant differences between clinic superintendents in public hospitals and hospital companies. This is true in terms of organizational commitment and cost consciousness. However, the study indicates that participation in the hospital budget-setting process and satisfaction with financial information both affect the superintendents' cost consciousness.
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| 4. |
- Bayani, Mohsen, 1981, et al.
(författare)
-
Geometric robustness and dynamic response management by structural topometry optimisation to reduce the risk for squeak and rattle
- 2022
-
Ingår i: Design Science. - : Cambridge University Press (CUP). - 2053-4701. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Historically, squeak and rattle (S&R) sounds have been among the top quality problems and a major contributor to the warranty costs in passenger cars. Geometric variation is among the main causes of S&R. Though, geometric variation analysis and robust design techniques have been passively involved in the open-loop design activities in the predesign-freeze phases of car development. Despite the successful application of topometry optimisation to enhance attributes such as weight, durability, noise and vibration and crashworthiness in passenger cars, the implementation of closed-loop structural optimisation in the robust design context to reduce the risk for S&R has been limited. In this respect, the main obstacles have been the demanding computational resources and the absence of quantified S&R risk evaluation methods. In this work, a topometry optimisation approach is proposed to involve the geometric variation analysis in an attribute balancing problem together with the dynamic response of the system. The proposed method was used to identify the potential areas of a door component that needed structural reinforcement. The main objective was to enhance the design robustness to minimise the risk for S&R by improving the system response to static geometrical uncertainties and dynamic excitation.
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| 5. |
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| 6. |
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| 7. |
- Lindkvist, Lars, et al.
(författare)
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The vision gives wings: A study of two hospitals run as limited companies
- 2004
-
Ingår i: Management Accounting Research. - : Elsevier BV. - 1044-5005 .- 1096-1224. ; 15:3, s. 305-318
-
Tidskriftsartikel (refereegranskat)abstract
- On 1 January 2000, the hospitals in Helsingborg and Ängelholm in the south of Sweden where reorganised as limited companies. This paper examines the outcome of the company formation and what mechanisms that result in change when the hospital is transferred from a local authority regime to a business-like form. The study shows that company formation in hospitals does have effects. On the short view (the first year studied), production increases and the financial situation improves. The study also shows that the leadership of the hospitals becomes more commercially minded and develops more rapid decision making procedures. The new found freedoms, the new financial structures and the possibilities to perform without budget restrictions create a foundation for goal-congruence between the medical professionals and the hospital leaderships and a common vision to strive for. This vision, to create something new in Swedish healthcare, gives wings to the organisations.
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| 8. |
- Lundh, Simon, 1980-
(författare)
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Implementation of IFRS reporting in Sweden : an interview study
- 2009
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In 2002 EU decided to require all listed companies in the European Union to prepare group accounts in accordance with IFRS for accounting periods starting on or a er 1 January 2005. e overall aim of this study is to explore public companies’ implementation of IFRS. More specifically, the study will identify and analyse the changes and challenges in group accounting for pu- blic companies implementing IFRS. e study explores how the companies in question actually experienced the implementation of IFRS instead of merely speculating on what might happen.e study is an explorative study, and consists of an interview-based study with nine interviews. e companies included in the study are listed on a Swedish market and the study consists of interviews with key people, such as Heads of Group Accounts, Chief Financial Officers (CFOs) or people with similar positions in the companies.e findings show that the implementation from a de jure point of view se- emed to imply significant group accounting changes for the public companies. As Swedish standard setters had started the convergence to international stan- dards before the implementation of IFRS, the changes in group accounting were not as great as they could have been. Overall, the companies in the study did not experience a lot of issues when implementing IFRS. Most of the issues discussed in the interviews seems to have been minor in nature. While the extent of issues experienced was minimal when the companies in the study implemented IFRS, the most common solution to a problem was to hire an accounting consultant company. Another finding from the study was that the companies most o en followed the new standards and also agreed with most of the requirements in- cluded in them. e standards was enforced mainly by the auditors and these were o en the very same companies that provided accounting consulting.
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| 9. |
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| 10. |
- Alvesson, Mats, et al.
(författare)
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Transaction Costs, Clans and Corporate Culture.
- 2004
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Ingår i: The International Library of the New Institutional Economics. - : Edward Elgar Publishing Ltd. - 1843766647 - 9781843766643 ; , s. -666
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 11. |
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| 12. |
- Andersson, Alf, et al.
(författare)
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Inline Process Control – a concept study of efficient in-line process control and process adjustment with respect to product geometry
- 2016
-
Ingår i: Swedish Production Symposium 2016 SPS 2016. - Lund, Sweden.
-
Konferensbidrag (refereegranskat)abstract
- All manufacturing processes have variation which may violate the fulfillment of assembly, functional, geometrical or esthetical requirements and difficulties to reach desired form in all areas. The cost for geometry defects rises downstream in the process chain. Therefore, it is vital to discover these defects as soon as they appear. Then adjustments can be done in the process without losing products or time. In order to find a solution for this, a project with the overall scope “development of an intelligent process control system” has been initiated. This project consists of five different work packages: Inline measurement, Process Evaluation, Corrective actions, Flexible tooling and demonstrator cell. These work packages address different areas which are necessary to fulfill the overall scope of the project. The system shall both be able to detect geometrical defects, propose adjustments and adjust simple process parameters. The results are demonstrated in a demo cell located at Chalmers University of Technology. In the demonstrator all the different areas have been verified in an industrial case study – assembly of GOR Volvo S80. Efficient offline programming for robot based measurement, efficient process evaluation based on case base reasoning (CBR) methodology, flexible fixtures and process adjustments based on corrective actions regarding in going part positioning.
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| 13. |
- Aronsson, August, 1980-
(författare)
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Löfte, tvist och försoning : Politikens spelregler i 1300-talets Norden
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis aims to explain how politics in 14th century Scandinavia were structured by a set of rules or norms of conduct – rules which were neither codified nor enforced by any outside agency, yet had a very real impact on the patterns by which political action was conducted. Taking inspiration from historical anthropology, the study sets out to analyze the ways in which political tensions and relationships, primarily within the royal elite, were negotiated in various situations. The source material – mainly letters of treaties, but also contemporary literary sources – are treated as remains of political communication within a common discursive framework.The findings of the study go against some established notions about politics in the 14th century that are prevalent in current Scandinavian research. On the whole, patterns of political behaviour during the period show great similarities to those of the earlier Middle Ages, despite the discontinuity implied by the idea of the 13th century as the era of "state formation" in Scandinavia. Rather, the kings and princes of the 14th century appear to have been ruled by quite similar norms of behaviour to those of their predecessors, albeit on a more complex scale.The concepts of peace and justice are shown to have been central to the way that political action was legitimized. No functional difference can be shown to have been made between "feudal" or personal relations, and those of the state. Peace was conceived as a state of harmony, which could only be achieved through the establishment of mutual positive bonds, and an active striving for justice. The latter was achieved, both with the aid of mediators and negotiators, and through the demonstration of force, in patterns largely similar to the practice of feuding. Likewise, acts of supplication and reconciliation are shown to have played an active part in the way that political relations were reified during the process of ending an armed conflict.
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| 14. |
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| 15. |
- Banitz, Thomas, et al.
(författare)
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Model-derived causal explanations are inherently constrained by hidden assumptions and context : The example of Baltic cod dynamics
- 2022
-
Ingår i: Environmental Modelling & Software. - : Elsevier BV. - 1364-8152 .- 1873-6726. ; 156
-
Tidskriftsartikel (refereegranskat)abstract
- Models are widely used for investigating cause-effect relationships in complex systems. However, often different models yield diverging causal claims about specific phenomena. Therefore, critical reflection is needed on causal insights derived from modeling. As an example, we here compare ecological models dealing with the dynamics and collapse of cod in the Baltic Sea. The models addressed different specific questions, but also vary widely in system conceptualization and complexity. With each model, certain ecological factors and mechanisms were analyzed in detail, while others were included but remained unchanged, or were excluded. Model-based causal analyses of the same system are thus inherently constrained by diverse implicit assumptions about possible determinants of causation. In developing recommendations for human action, awareness is needed of this strong context dependence of causal claims, which is often not entirely clear. Model comparisons can be supplemented by integrating findings from multiple models and confronting models with multiple observed patterns.
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| 16. |
- Banitz, Thomas, et al.
(författare)
-
Visualization of causation in social-ecological systems
- 2022
-
Ingår i: Ecology and Society. - : Resilience Alliance, Inc.. - 1708-3087. ; 27:1
-
Tidskriftsartikel (refereegranskat)abstract
- In social-ecological systems (SES), where social and ecological processes are intertwined, phenomena are usually complex and involve multiple interdependent causes. Figuring out causal relationships is thus challenging but needed to better understand and then affect or manage such systems. One important and widely used tool to identify and communicate causal relationships is visualization. Here, we present several common visualization types: diagrams of objects and arrows, X-Y plots, and X-Y-Z plots, and discuss them in view of the particular challenges of visualizing causation in complex systems such as SES. We use a simple demonstration model to create and compare exemplary visualizations and add more elaborate examples from the literature. This highlights implicit strengths and limitations of widely used visualization types and facilitates adequate choices when visualizing causation in SES. Thereupon, we recommend further suitable ways to account for complex causation, such as figures with multiple panels, or merging different visualization types in one figure. This provides caveats against oversimplifications. Yet, any single figure can rarely capture all relevant causal relationships in an SES. We therefore need to focus on specific questions, phenomena, or subsystems, and often also on specific causes and effects that shall be visualized. Our recommendations allow for selecting and combining visualizations such that they complement each other, support comprehensive understanding, and do justice to the existing complexity in SES. This lets visualizations realize their potential and play an important role in identifying and communicating causation.
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| 17. |
- Bayani, Mohsen, 1981, et al.
(författare)
-
Squeak and rattle prevention by geometric variation management using a two-stage evolutionary optimisation approach
- 2020
-
Ingår i: ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE). ; 2B-2020
-
Konferensbidrag (refereegranskat)abstract
- Squeak and rattle are annoying sounds that often are regarded as the indicators for defects and quality issues by the automotive customers. Among the major causes for the generation of squeak and rattle sounds, geometric variation or tolerance stack-up is a key contributor. In the assembly process, the dimensional variation in critical interfaces for generating squeak and rattle events can be magnified due to tolerance stackup. One provision to manage the tolerance stack-up in these critical interfaces is to optimise the location of connectors between parts in an assembly. Hence, the focus of this work is to prevent squeak and rattle by introducing a geometric variation management approach to be used in the design phase in the automotive industry. The objective is to identify connection configurations that result in minimum variation and deviation in selected measure points from the critical interfaces for squeak and rattle. In this study, a two-stage evolutionary optimisation scheme, based on the genetic algorithm employing the elitism pool, is introduced to fine-tune the connectors’ configuration in an assembly. The objective function was defined as the variation and the deviation in the normal direction and the squeak plane. In the first stage, the location of one-dimensional connectors was found by minimising the objective function in the rattle direction. In the second stage, the best combination of some of the connectors from the first stage was found to define planar fasteners to optimise the objective function both in the rattle direction and the squeak plane. It was shown that by using the proposed two-stage optimisation scheme, the variation and deviation results in critical interfaces for squeak and rattle improved compared to the baseline results.
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| 18. |
- Bayani, Mohsen, 1981, et al.
(författare)
-
Squeak and rattle prevention by geometric variation management using a two-stage evolutionary optimization approach
- 2022
-
Ingår i: Journal of Computing and Information Science in Engineering. - : ASME International. - 1530-9827 .- 1944-7078. ; 22:1
-
Tidskriftsartikel (refereegranskat)abstract
- Squeak and rattle are annoying sounds that are often regarded as failure indicators by car users. Geometric variation is a key contributor to the generation of squeak and rattle sounds. Optimization of the connection configuration in assemblies can be a provision to minimize this risk. However, the optimization process for large assemblies can be computationally expensive. The focus of this work is to propose a two-stage evolutionary optimization scheme to find the fittest connection configurations that minimize the risk for squeak and rattle. This was done by defining the objective functions as the measured variation and deviation in the rattle direction and the squeak plane. In the first stage, the location of the fasteners primarily contributing to the rattle direction measures is identified. In the second stage, fasteners primarily contributing to the squeak plane measures are added to the fittest configuration from phase one. It was assumed that the fasteners from the squeak group plane have a lower-order effect on the rattle direction measures, compared to the fasteners from the rattle direction group. This assumption was falsified for a set of simplified geometries. Also, a new uniform space filler algorithm was introduced to efficiently generate an inclusive and feasible starting population for the optimization process by incorporating the problem constraints in the algorithm. For two industrial cases, it was shown that by using the proposed two-stage optimization scheme, the variation and deviation measures in critical interfaces for squeak and rattle improved compared to the baseline results.
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| 19. |
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| 20. |
- Bengtsson, Marie, et al.
(författare)
-
Mapping the Road to Future Projects : Roadmapping as a Balancing and Transformation Process
- 2017
-
Ingår i: Project Management Journal. - : John Wiley & Sons. - 8756-9728 .- 1938-9507. ; 48:2, s. 39-54
-
Tidskriftsartikel (refereegranskat)abstract
- Based on a longitudinal case study in a large technology-based firm, this article shows how roadmapping can bring about an increased focus on explorative activity and a stronger future orientation in an organization. The case study shows how a radical technology vision, presented in the first roadmapping attempt, contributed to creating an awareness of the value of looking long into the future. This was, however, far from sufficient, and a second attempt with a stronger focus on collaboration and new knowledge generation was initiated to further the desired changeover. Interestingly, the case study points to the significance of visualizations as a means to support knowledge generation, as well as to protect exploration. More generally, we propose how roadmapping can be developed into a balancing and transformation tool associated with mapping as well as the creation of roads.
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| 21. |
- Bengtsson, Marie, 1977-
(författare)
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The Art of Replicating
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fokus för den här avhandlingen är företag som växer genom replikering, det vill säga genom att skapa och driva liknande enheter på många olika platser, så som t.ex. McDonald’s och Starbucks. Replikerande företags livscykel beskrivs normalt i termer av en initial utforskande fas, följt av en exploateringsfas där standardisering är en hörnsten i företagets strategi - vad som därefter följer är emellertid oklart. Varsamt åldrande innebär dock vanligtvis att man måste anta de utmaningar som följer i kölvattnet av stabilitet och förändring.Modeindustrin kan beskrivas som oberäknelig och föränderlig, och har varit så i århundraden. Konkurrensen är stenhård och efterfrågan är svår att förutse då mode och trender hela tiden förändras. Med tanke på det beroende av standadisering som finns i replikerande företag kan man fråga sig hur ett företag i modebranschen kan hantera en replikeringsstrategi. Den trade-off som finns mellan fördelarna av standardisering och fördelarna av lärande och anpassning ställs på sin spets i ett sådant företag.Renässansen stora konstnärer mötte en liknande utmaning om än i lite annan form. Baserat på kollektivt arbete skapade renässansens verkstäder såväl replikor som nya verk i mästarens namn. För verkstaden betydde det att de skulle replikera mästarens stil till den grad att enskilda bidrag från lärlingar inte gick att skilja från mästarens eget arbete. Nya lärlingar var tvungna att lära sig att “emulera” mästarens stil och fungerar som en förlängning av hans hand och öga.Den här avhandlingen tar därför avstamp i konstens värld, mer specifikt i Renässansen, för att utforska hur ett konstinspirerat förhållningssätt kan öka vår förståelse av replikeringsprocesser i erfarna företag som är verksamma i starkt föränderliga branscher och vars strategi bygger på replikering. Det empiriska underlaget för avhandlingen är en djupgående fallstudie av den svenska modekedjan Hennes & Mauritz, och bygger på deltagande observation såväl i etablerade butiker som under öppningen av nya.
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| 22. |
- Berggren, Christian, 1950-, et al.
(författare)
-
Projekt : organisation för målorientering och lärande
- 2001. - 1
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- Svenska industriföretag, tjänsteföretag och offentliga organisationer väljer i allt högre utsträckning att bedriva verksamhet i projektform. Projektet som arbetsform har gått från att ha varit något av en undantagslösning för unika insatser till att idag framstå som en ”grundbult” i sättet att organisera stora delar av verksamheten inom företag och organisationer. Därmed har också behovet av kunskaper om projektstyrning och projektorganisation ökat dramatiskt. I denna bok behandlas ledning, organisering och lärande i olika typer av projekt. Genom att boken tydligt tar sin utgångspunkt i konkreta fallbeskrivningar och kopplar dessa till aktuell organisations- och projektforskning, lämpar den sig som lärobok på projekt- och organisationskurser inom ekonom-, ingenjörs-, civilingenjörs- och systemvetarutbildningar vid universitet och högskolor. Den är också väl lämpad att användas som kursbok i företagsintern vidareutbildning, och på universitetens externa kurser och ledarskapsprogram. Boken är även intressant för var och en som på egen hand vill fundera över projektorganisationens för- och nackdelar.
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| 23. |
- Blomquist, Tomas, 1963-, et al.
(författare)
-
Ekonomisk styrning för förändring : en studie av ekonomiska styrinitiativ i hälso- och sjukvården
- 1998
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Since the end of the 1980’s Swedish county council managers has been preoccupied with planning and implementing organisational change in order to alleviate the financial problems and to create more efficient production systems. Many of these efforts to change have implied changing the systems for management accounting and control, changes that have been inspired both by market-oriented ideologies and by the governance principles of large corporations in the private sector. Literature on management accounting and control indicates however, that management is unintentionally contributing to the creation of organisational inertia and conservatism. This contradiction is formulated as a change dilemma; ”How can managerial principles that make organizations subject to bureaucratization and inertia be used as important strategies for organizational change?” The purpose of the study is thus to analyze the use of management control systems as organizational change strategies in health care, employing a change perspective on management control.When used as a change strategy, management accounting and control becomes manifest as management control initiatives. Actors handle these control inititatives by organising themselves around the issue at hand. This organising process ends or fades away when there are no need for further attention to the control initiative.Empirical studies were made in the councils of Västerbotten, Sörmland and Uppsala counties. Management control initiatives investigated were performance-related pay, quality improvement work, systematic planning procedures, provider/purchaser-models, downsizing projects and profit center systems.The systems for management accounting and control appeared to structure health care organisations in terms of spatial structuring temporal structuring and actor categorization. The management control initiatives introduced were structured as extraordinary organising processes delimited in terms of space, time and involved actors. Actors in the administrative norm system participated with the intention to change the organisation, while those in the medical norm system aimed at just handling the initiative.Management control initiatives can therefore be seen as passing opportunities to change, passing in the sense that the organising processes are temporary by nature, opportunities in the sense that temporary re-coupling can be used to achieve long-term change. One such opportunity is the formulation of control initiatives; the possibility of using simple and standardized change strategies can be useful, but only if they are also linked to the medical norm system. A second opportunity is the temporary organising processes; if the project form of organising change can also be conveyed to the medical norm system, management control initiatives could result in short, intense courses of events that actually change things. The third opportunity s the recurrent cyc ica pro perties of management accounting and control systems, enabling recurrent activities around the same themes, thereby keeping them alive.
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| 24. |
- Bohlin, Robert, 1972, et al.
(författare)
-
Data Flow and Communication Framework Supporting Digital Twin for Geometry Assurance
- 2018
-
Ingår i: ASME 2017 International Mechanical Engineering Congress and Exposition. ; 2
-
Konferensbidrag (refereegranskat)abstract
- Faster optimization algorithms, increased computer power and amount of available data, can leverage the area of simulation towards real-time control and optimization of products and production systems. This concept — often referred to as Digital Twin — enables real-time geometry assurance and allows moving from mass production to more individualized production. To master the challenges of a Digital Twin for Geometry Assurance the project Smart Assembly 4.0 gathers Swedish researchers within product development, automation, virtual manufacturing, control theory, data analysis and machine learning. The vision of Smart Assembly 4.0 is the autonomous, self-optimizing robotized assembly factory, which maximizes quality and throughput, while keeping flexibility and reducing cost, by a sensing, thinking and acting strategy. The concept is based on active part matching and self-adjusting equipment which improves geometric quality without tightening the tolerances of incoming parts. The goal is to assemble products with higher quality than the incoming parts. The concept utilizes information about individual parts to be joined (sensing), selects the best combination of parts (thinking) and adjust locator positions, clamps, weld/rivet positions and sequences (acting). The project is ongoing, and this paper specifies and highlights the infrastructure, components and data flows necessary in the Digital Twin in order to realize Smart Assembly 4.0. The framework is generic, but the paper focuses on a spot weld station where two robots join two sheet metal parts in an adjustable fixture.
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| 25. |
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| 26. |
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| 27. |
- Carlson, Johan, 1972, et al.
(författare)
-
Non-nominal path planning for robust robotic assembly
- 2013
-
Ingår i: Journal of Manufacturing Systems. - : Elsevier BV. - 0278-6125. ; 32:3, s. 429-435
-
Tidskriftsartikel (refereegranskat)abstract
- In manufacturing and assembly processes it is important, in terms of time and money, to verify the feasi-bility of the operations at the design stage and at early production planning. To achieve that, verificationin a virtual environment is often performed by using methods such as path planning and simulation ofdimensional variation. Lately, these areas have gained interest both in industry and academia, however,they are almost always treated as separate activities, leading to unnecessary tight tolerances and on-lineadjustments.To resolve this, we present a novel procedure based on the interaction between path planning tech-niques and variation simulation. This combined tool is able to compute robust assembly paths forindustrial robots, i.e. paths less sensitive to the geometrical variation existing in the robot links, in itscontrol system, and in the environment. This may lead to increased productivity and may limit errorsources. The main idea to improve robustness is to enable robots to avoid motions in areas with highvariation, preferring instead low variation zones. The method is able to deal with the different geometricalvariation due to the different robot kinematic configurations. Computing variation might be a computa-tionally expensive task or variation data might be unavailable in the entire state space, therefore threedifferent ways to estimate variation are also proposed and compared. An industrial test case from theautomotive industry is successfully studied and the results are presented.
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| 28. |
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| 29. |
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| 30. |
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| 31. |
- Dagman, Andreas, 1976, et al.
(författare)
-
Form division in automobile design - linking design and manufacturability
- 2006
-
Ingår i: Design 2006 9th International Design Conference, May 15-18, 2006, Dubrovnik, Croatia, Editor Marjanovic´, D. - 9536313790 ; 1, s. 495-502
-
Konferensbidrag (refereegranskat)
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| 32. |
- Dagman, Andreas, et al.
(författare)
-
Split-line design for given geometry and location schemes
- 2007
-
Ingår i: Journal of engineering design (Print). - : Informa UK Limited. - 0954-4828 .- 1466-1837. ; 18:4, s. 373-388
-
Tidskriftsartikel (refereegranskat)abstract
- The spatial relations between parts in an assembly can be critical for the functional and aesthetic quality of a product. In the case of the automobile, these relations can be between doors, fenders, hood, panels, and so on. Variation in these relations, caused by part and assembly variation, influences the output variation, which is what the customer sees and judges. This paper presents a computer-aided tolerancing tool that supports and improves split-line design with respect to geometrical variation. A split-line is the relation between two mating parts over a distance. The design and placement of a split-line in an automobile body are influenced by several aspects such as design language, geometrical dimensioning, crash safety, and so on. In this paper only the geometrical dimensioning aspects have been considered. The research has been carried out using simulations and analyses in a computer-aided tolerancing software. The tool presented describes a way to calculate and visualize the geometrically most robust area and split-line between two parts. The findings from the research show that it is difficult to calculate and visualize the result in flush and gap directions in the same way. The tool gives insight into how the configuration of the locating schemes influences the geometrical robustness of the design.
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| 33. |
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| 34. |
- Dahlström, Stefan, 1972, et al.
(författare)
-
Variation simulation of sheet metal assemblies using the method of influence coefficients with contact modeling
- 2007
-
Ingår i: Journal of Manufacturing Science and Engineering, Transactions of the ASME. - : ASME International. - 1087-1357 .- 1528-8935. ; 129:3, s. 615-622
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Tidskriftsartikel (refereegranskat)abstract
- Sheet metal assembly is a common assembly process for several products such as automobiles and airplanes. Since all manufacturing processes are affected by variation, and products need to have a high geometric quality, geometry-related production problems must be analyzed during early design phases. This paper discusses two methods of performing this analysis. One way of performing the simulations relatively fast is to establish linear relationships between part deviation and assembly springback deviation by using the method of influence coefficient (MIC). However, this method does not consider contact between the parts. This means that the parts are allowed to penetrate each other which can affect the accuracy of the simulation result. This paper presents a simple contact modeling technique that can be implemented in to MIC to avoid penetrations. The contact modeling consists of a contact detection and a contact equilibrium search algorithm. When implemented, MIC still only requires two finite element analysis (FEA) calculations. This paper describes the steps in the contact algorithm and how it can be used in MIC and finally the proposed contact modeling is verified by comparing the simulation result with commercial FEA software ABAQUS contact algorithm.
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| 35. |
- Digerfeldt-Månsson, Theresa, 1964-
(författare)
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Formernas liv i designföretaget : Om design och design management som konst
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Design management has become strongly associated with strategic management of creative resources or immaterial assets within the creative economy. It is a development that has involved a growing interest in the way innovative and aesthetically oriented design companies use design as a resource. They constitute a category of companies that claim to represent a unique way of looking upon design itself and also a more intuitive and entrepreneurial design management philosophy. The research concerns Swedish so-called “radical design innovators” who are active in the furniture and interior decoration industry. The study is based on in-depth interviews with leaders, and the aim has been to gain greater insight into how they look upon design as a resource. The study was done from an art point of view. Since design management, due to its alliance with creative economy, has incorporated aspects traditionally associated with the artistic sphere, the aim of the study has also been to improve our theoretical understanding of how art broadens the way by which design is looked upon as a creative resource. Art is represented by Henri Focillon and his notion of “form as life”. Art is understood as something that belongs to knowledge and reality directly at a basic level. The study shows that the design leaders perceive design-form as a poetic image, i.e. as a “lived” quality that escapes verbal definition as it appears as a movement in space, matter, mind, and time. It also shows how their intuitive design management philosophy can only be understood if we look upon design as an artistic process, i.e. a process based on the dynamic relationship between seeing, doing, and bodily being-in-the-world. To sum up the study shows the importance of conceptualizing radical design innovators as aesthetic actors - and not only as innovative ones - if we are to achieve a fuller understanding of where their creative potential resides.
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| 36. |
- Edholm, Peter, 1974, et al.
(författare)
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Geometrical Coupling Analysis to Reduce Complete Assembly Line Complexity
- 2012
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Ingår i: Proceedings of the ASME 2012 International Mechanical Engineering Congress & Exposition, IMECE2012, November 9-15, 2012, Houston, Texas, USA. - 9780791845196 ; 3:PARTS A, B, AND C, s. 89-96
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Konferensbidrag (refereegranskat)abstract
- Modern assembly lines for mass production need to fulfill several important criteria. One of them is to produce products with high geometrical quality (small geometric variation). For sheet metal assemblies, focused on in this paper, it is a very complex process to achieve good geometrical quality due to the large number of assembly steps and the geometrical variation (tolerances) of the incoming parts. One “golden rule” for sheet metal assembly lines is to always reuse fixturing points (locators) throughout the whole assembly line to minimize the geometrical variation and also the complexity of root cause analysis.A new method to measure the complexity in an assembly line has been developed and also implemented in a commercial software for Computer Aided Tolerancing. This new tool not only demonstrates the “golden rule” but could also be used to ensure minimum geometrical complexity in assembly lines to ensure controlled production and high quality products.
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| 37. |
- Edholm, Peter, 1974, et al.
(författare)
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Geometry robustness evaluation for common parts in platform architecture
- 2011
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Ingår i: International Journal of Shape Modeling. - 0218-6543. ; 16:1&2, s. 129-150
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a platform geometrical sensitivity value for a part has been defined. Calculation and simulation methods have been defined and tested to be used in industrial “real-life” environments. Present calculation and simulation methods for assembly analysis in a single product development have been used as a basis. These methods have been further developed and adapted to suit product family development, or platforms. The assembly geometrical sensitivity value can be used to predict the effect of tolerance stacking without having data of tolerance sizes available. Using sensitivity calculation in each assembly step gives an indication of the risk of functional failure and non-fulfilled specifications due to tolerance stacking. The platform geometrical sensitivity value could be used for optimization of a part or an assembly, by means of geometric variation, not only for one product environment but also for a complete product family simultaneously. This decreases the risk of sub-optimization of part location and assembly concepts. Using the platform geometrical sensitivity value, the effect of tolerance stacking could be predicted for all assemblies conceptually and the result can be used to dimension specific part tolerances. All equations and mathematical connections are described in detail in the paper but, due to the mathematical complexity of 3D modeling, the calculations have been performed in a geometry simulation tool. Further research needs to be done to establish a proper working procedure using platform geometrical sensitivity value.
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| 38. |
- Edholm, Peter, 1974, et al.
(författare)
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Geometry robustness evaluation for common parts in platform architecture
- 2010
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Ingår i: Proceedings of the 8th International Symposium on Tools and Methods of Competitive Engineering, TMCE 2010. April 12–16, 2010, Ancona, Italy. - 9789051550603 ; 2, s. 1003-1012
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Konferensbidrag (refereegranskat)abstract
- In this paper, a platform geometry goodness value for a part has been defined. Calculation and simulation methods have been defined and tested to be used in industrial "real-life" environments. Present calculation and simulation methods for assembly analysis in a single product development have been used as a basis. These methods have been further developed and adapted to suit product family development, or platforms. The platform geometry robustness value could be used for optimization of a part or an assembly, by means of geometric variation, not only for one product environment but also for a complete product family simultaneously. This decreases the risk of suboptimization of part location and assembly concepts. All equations and mathematical connections are described in detail in the paper but, due to the mathematical complexity of 3D modelling, the calculations have been performed in a geometry simulation tool. The proposed theories are based on previous work by Söderberg [7] presented mainly in section 2. The new contribution from this paper is mainly presented in sections 4.2 and 5.
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| 39. |
- Edholm, Peter, 1974, et al.
(författare)
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Minimizing Geometric Variation in Multiusage Assembly Line by Geometrical Decoupling
- 2011
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Ingår i: ASME 2011 International Mechanical Engineering Congress and Exposition, IMECE2011, November 11-17, 2011, Denver, Colorado, USA. - 9780791854891 ; 3, s. 63-71
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Konferensbidrag (refereegranskat)abstract
- Geometrical part robustness is today used as an engineering criterion in many manufacturing companies. The goal is to minimize the effect of geometrical variation by optimizing the locating schemes for the parts. Several methods and tools are today present to support geometrical robustness optimization for parts but also for assemblies. In this paper focus is on geometrical decoupling, which is one parameter of geometrical robustness, of the different locating strategies in a complete assembly line. A goodness value is proposed that describe the level of geometrical couplings in a complete assembly line together with the part robustness value. By calculating this goodness value it is possible to predict the geometrical sensitivity of a complete assembly line as well as predicting the risk of geometrical variation on the final product. To illustrate the definition of this goodness value, and also the purpose of calculating it, a case study is used where a part of a sheet metal assembly line is described. Several different scenarios (assembly concepts) are applied to clarify the meaning and to validate this definition of the goodness value. The case study shows that the goodness value gives a good indication of the level of geometrical couplings within the assembly line and that this value could be used to evaluate different assembly concepts, with their locating concepts, against each other. The goal is to have a more robust and also geometrically decoupled assembly line which the root cause analysis in production and also optimizes the geometrical quality minimizing the effect of geometrical variation of the final product from the plant.
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| 40. |
- Enberg, Cecilia, et al.
(författare)
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Exploring the dynamics of knowledge integration : Acting and interacting in project teams
- 2006
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Ingår i: Management Learning. - : SAGE Publications. - 1350-5076 .- 1461-7307. ; 37:2, s. 143-165
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Tidskriftsartikel (refereegranskat)abstract
- This article investigates knowledge integration in product development projects. While much previous literature draws attention to the need for clearly specified goals, extensive knowledge sharing and close face-to-face interaction for activity and knowledge integration, alternative explanations are offered. The findings highlight the integrative capacity of individuals' experience and tacit foreknowledge of the stacker artefact, as well as the complementary role of meetings and ad hoc problem solving. The article proposes an iterative model of the individual/collective dynamics involved and calls attention to its economizing potential. More generally, it provides an example of how the issue of knowledge integration may be reformulated into a dynamic perspective, recognizing the intergenerational learning benefits that accrue. The conclusions extend the argument of Zollo and Winter by showing how different task-related learning mechanisms may be combined and obtain their integrative capacity within an iterative process. Copyright © 2006 Sage Publications.
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| 41. |
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| 42. |
- Enberg, Cecilia, et al.
(författare)
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Knowledge integration at the edge of technology: On teamwork and complexity in new turbine development
- 2010
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Ingår i: INTERNATIONAL JOURNAL OF PROJECT MANAGEMENT. - : Elsevier Science B.V., Amsterdam.. - 0263-7863 .- 1873-4634. ; 28:8, s. 756-765
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Tidskriftsartikel (refereegranskat)abstract
- This paper takes an empirical point of departure in the development of a new steam turbine. Project work here relied on a process of iteration between a small core group of team members with extensive experience and team members with less of that currency. In this project, the core group had a major integrative role, whereas other team members were mainly responsible for the specific tasks assigned to them. Quite a few of the latter category felt uneasy about their role and felt decoupled from the project. In our analysis we use the Teamwork Quality (TWQ) construct proposed by Hoegl and Gemuenden (2001). In conclusion, our findings suggest that in highly complex projects of this type, team-based knowledge integration need not presuppose equality of participation and we introduce the notion of a Segregated Team to account for these findings.
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| 43. |
- Enberg, Cecilia, 1976-
(författare)
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Knowledge Integration in Product Development Projects
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Denna avhandling handlar om kunskapsintegration i produktutvecklingsprojekt. Med kunskapsintegration avses processer av mål-orienterad interrelatering med syfte att dra fördel av de kunskapskomplementariteter som finns mellan individer som har differentierade kunskapsbaser. Förmågan att integrera specialiserad och distribuerad kunskap är betydelsefull för många företag då den bidrar till att förklara skillnader i produktutvecklingsframgång. Dock saknas det detaljerade, empiriska, studier av kunskapsintegration. Mot denna bakgrund är syftet med denna avhandling att undersöka vilka kunskapsintegrationsmekanismer som är lämpliga att använda i olika projektkontexter.Avhandlingen är baserad på två longitudinella realtidsstudier av produktutvecklingsprojekt. En detaljerad redogörelse av projektarbetet, tillsammans med en analys, presenteras för respektive projekt. Därefter görs en komparativ analys, i vilken såväl likheter som olikheter mellan de två fallen och deras respektive projektkontext diskuteras. En iterativ modell för kunskapsintegration förslås som ett resultat av studierna. Den iterativa modellen har ett flertal egenskaper som kan bidra till att öka vår förståelse för kunskapsintegration i empiriska projektkontexter. För det första visar den på vikten av att förstå i vilken utsträckning som kunskapsproblematiken i ett specifikt projekt medför behov av såväl ”aktion” som ”interaktion” och hur dessa kompletterar varandra i en iterativ process. För det andra indikerar den betydelsen av artefakter och hur dessa kan bidra till såväl aktion som interaktion. För det tredje tar den hänsyn till det faktum att aktion och interaktion medför olika kostnader för kunskapsintegration.
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Enberg (f.d Frohm), Cecilia, 1976-, et al.
(författare)
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Interacting and interrelating in projects : exploring the individual-collective cynamic in teamwork
- 2004
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Konferensbidrag (refereegranskat)abstract
- Skillful planning and the reliance on frequent face-to-face interaction is often emphasized as preconditions for successful project work in literature on project management and product development. Our case study observations of a project involving the development of a new stacker, however, contrast with such a view. Here, most project work was carried out individually and as a matter of routine, complemented by interactive instances, such as project meetings and ad hoc problem solving interaction. Moreover, instead of a shared project goal or a shared knowledge base, the material stacker stood out as an artifact of great significance in achieving activity and knowledge coordination. Inspired by literature on sense-making, we propose a simplified model of the individual-collective dynamic in such contexts, and differentiate between processes of interacting and interrelating. Finally we discuss its coordination properties as a matter of cognitive feasibility and economizing on cost.
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| 48. |
- Forslund, Anders, 1982, et al.
(författare)
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Minimizing Weld Variation Effects Using Permutation Genetic Algorithms and Virtual Locator Trimming
- 2018
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Ingår i: Proceedings of the ASME 2017 International Mechanical Engineering Congress and Exposition. ; 2
-
Konferensbidrag (refereegranskat)abstract
- The mass production paradigm strives for uniformity, and for assembly operations to be identical for each individual product. To accommodate geometric variation between individual parts in such a process, tolerances are introduced into the design. However, for certain assembly operations this method can yield suboptimal quality. For instance, in welded assemblies, geometric variation in ingoing parts can significantly impair quality. When parts misalign in interfaces, excessive clamping force must be applied, resulting in additional residual stresses in the welded assemblies. This problem may not always be cost-effective to address simply by tightening tolerances. Therefore, under new paradigm of mass customization, the manufacturing approach can be adapted on an individual level. Since parts in welded assemblies are not easily disassembled and reused, interchangeability is not a relevant concern. This recognition means that each welded assembly can be adapted individually for the specific idiosyncrasies of ingoing parts. This paper focuses on two specific mass customization techniques; permutation genetic algorithms to assemble nominally identical parts, and virtual locator trimming. Based on these techniques, a six-step method is proposed, aimed at minimizing thing effects of geometric variation. The six steps are nominal reference point optimization, permutation GA configuration optimization, virtual locator trimming, clamping, welding simulation, and fatigue life evaluation. A case study is presented which focuses on one specific product; the turbine rear structure of a commercial turbofan engine. Using this simulation approach, the effects of using permutation genetic algorithms and virtual locator trimming to reduce variation are evaluated. The results show that both methods significantly reduce seam variation. However, virtual locator trimming is far more effective in the test case presented, since it virtually eliminates seam variation. This can be attributed to the orthogonality in fixturing. Seam variation is linked to weldability, which in turn has significant impact on estimated fatigue life. These results underscore the potential of virtual trimming and genetic algorithms in manufacturing, as a means both to reduce cost and increase functional quality.
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| 49. |
- Forslund, Anders, 1982, et al.
(författare)
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Minimizing weld variation effects using permutation genetic algorithms and virtual locator trimming
- 2018
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Ingår i: Journal of Computing and Information Science in Engineering. - : ASME International. - 1530-9827 .- 1944-7078. ; 18:4
-
Tidskriftsartikel (refereegranskat)abstract
- The mass production paradigm strives for uniformity, and for assembly operations to be identical for each individual product. To accommodate geometric variation between individual parts, tolerances are introduced into the design. However, this method can yield suboptimal quality. In welded assemblies, geometric variation in ingoing parts can significantly impair quality. When parts misalign in interfaces, excessive clamping force must be applied, resulting in additional residual stresses in the welded assemblies. This problem may not always be cost-effective to address simply by tightening tolerances. Therefore, under new paradigm of mass customization, the manufacturing approach can be adapted on an individual level. This paper focuses on two specific mass customization techniques: permutation genetic algorithms (GA) and virtual locator trimming. Based on these techniques, a six-step method is proposed, aimed at minimizing the effects of geometric variation. The six steps are nominal reference point optimization, permutation GA configuration optimization, virtual locator trimming, clamping, welding simulation, and fatigue life evaluation. A case study is presented, which focuses on the selective assembly process of a turbine rear structure of a commercial turbofan engine, where 11 nominally identical parts are welded into a ring. Using this simulation approach, the effects of using permutation GAs and virtual locator trimming to reduce variation are evaluated. The results show that both methods significantly reduce seam variation. However, virtual locator trimming is far more effective in the test case presented, since it virtually eliminates seam variation. These results underscore the potential of virtual trimming and GAs in manufacturing, as a means both to reduce cost and increase functional quality.
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| 50. |
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