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- Bengtsson, Marcus, 1977-
(författare)
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On Condition Based Maintenance and its Implementation in Industrial Settings
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In order to stay competitive, it is necessary for companies to continuously increase the effectiveness and efficiency of their production processes. High availability has, thus, increased in importance. Therefore, maintenance has gained in importance as a support function for ensuring, e.g., quality products and on-time deliveries. Maintenance, though, is a costly support function. It has been reported that as much as 70% of the total production cost can be spent on maintenance. Further, as much as one-third of the cost of maintenance is incurred unnecessarily due to bad planning, overtime cost, limited or misused preventive maintenance, and so on. In so, condition based maintenance is introduced as one solution for a more effective maintenance.In condition based maintenance, critical item characteristics are monitored in order to gain early indications of an incipient failure. Research, though, has shown that condition based maintenance has not been implemented on a wide basis. Therefore, the purpose of this research is to investigate how a condition based maintenance approach can be implemented in an industrial setting, and to develop a method that can assist companies in their implementation efforts. Further, the research has been divided in three research questions. They focus on: constituents of a condition based maintenance approach, decision-making prior implementation of condition based maintenance, and finally, the implementation of condition based maintenance in a company.By using a systems approach and a case study process, how condition based maintenance can be implemented as a routine has been investigated. The result is an implementation method in which four suggested phases are presented. The method starts with a feasibility test. It then continues with an analysis phase, an implementation phase, and an assessment phase. The conclusions can be summarized as follows: implementing condition based maintenance consists of many general enabling factors, including management support, education and training, good communication, and motivation etc.
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| 3. |
- Bergh, Mats, 1968, et al.
(författare)
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The influence of surface micro-roughness on bondability
- 1995
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Ingår i: Proceedings of the Third International Symposium on Semiconductor Wafer Bonding: Physics and Applications. ; , s. 126-
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Konferensbidrag (refereegranskat)abstract
- The requirements on a surface in terms of micro-roughness necessary to achieve spontaneous bonding on wafer contact have been investigated. Wafers from four different manufacturers, all having their special surface characteristics, were evaluated using atomic force microscopy. Their room temperature bondability was investigated using the contact wave velocity and the surface energy of the formed bond as parameters. Different wet cleaning procedures were used to modify the micro-roughness of the silicon surface. It is found that the surface rms roughness value is not a good measure for judging the bondability of a surface. Instead we propose the use of the Fourier spectrum of the surface roughness. The occurrence of low, ~0.001 Å-1, spatial frequency components of large amplitude in the Fourier spectrum of the surface roughness may affect the bondability of the surface negatively while higher frequency components are not as important
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| 5. |
- Granlund, Anna, 1984-
(författare)
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Facilitating Automation Development in Internal Logistics Systems
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The internal logistics system includes all activities connected with managing the flow of materials within the physical limits of a facility. This system is an important part of operations in need of increased focus and continuous improvements. Automation is one possible tool with a previously confirmed great potential to improve internal logistics. Despite this great potential and a growing trend of using automation in the area, internal logistics activities are still not automated to the same extent as other parts of operations. The overall aim of this research is therefore to develop knowledge that supports the successful use of automation in internal logistics systems.The automation development process has been identified as critical for the success of the use of automation. With the overall aim of the research in mind, the objective of this thesis is to develop a framework facilitating the automation development process in internal logistics systems. To help fulfil the objective, empirical data have been collected through five case studies and a survey study. During the empirical studies, the process of improving the internal logistics system and the automation development process have been analysed and the focus has been on identifying challenges and facilitators for the successful use and development of automation in internal logistics systems.The findings indicate a poor awareness of both current and desired performance of the internal logistics system at the companies studied. In addition, automation development is often conducted in an unstructured and poorly supported manner and there is often insecurity regarding what steps and actions to take. Foremost, the findings indicate a poor base for proper evaluation and decisions during automation development in internal logistics systems. This is analysed and concluded as a cause of unclear goals and requirements and the lack of a strategic view with regard to both internal logistics operations and the use and development of automation.A framework, including proposed guidelines to overcome the observed challenges by including identified factors facilitating successful automation development in internal logistics systems has been developed. The core of the framework is a proposed process model for automation development in an internal logistics context. Due to the identified importance and the lack of a strategy linked to and supporting the automation development process, the framework also includes a proposed model for an internal logistics strategy as well as a proposed model for an automation strategy.
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| 6. |
- Hjelm-Wallén, Lena, et al.
(författare)
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Det behövs mer än värnplikt
- 2016
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Ingår i: Svenska dagbladet. - 1101-2412. ; :2016-10-07, s. 6-6
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Människors säkerhet handlar om mycket mer än det rent militära. Därför är det är dags att överväga att införa allmän medborgartjänst för alla medborgare kring tjugoårsåldern.
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| 7. |
- Abarenkov, Kessy, et al.
(författare)
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Annotating public fungal ITS sequences from the built environment according to the MIxS-Built Environment standard – a report from a May 23-24, 2016 workshop (Gothenburg, Sweden)
- 2016
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Ingår i: MycoKeys. - : Pensoft Publishers. - 1314-4057 .- 1314-4049. ; 16, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Recent molecular studies have identified substantial fungal diversity in indoor environments. Fungi and fungal particles have been linked to a range of potentially unwanted effects in the built environment, including asthma, decay of building materials, and food spoilage. The study of the built mycobiome is hampered by a number of constraints, one of which is the poor state of the metadata annotation of fungal DNA sequences from the built environment in public databases. In order to enable precise interrogation of such data – for example, “retrieve all fungal sequences recovered from bathrooms” – a workshop was organized at the University of Gothenburg (May 23-24, 2016) to annotate public fungal barcode (ITS) sequences according to the MIxS-Built Environment annotation standard (http://gensc.org/mixs/). The 36 participants assembled a total of 45,488 data points from the published literature, including the addition of 8,430 instances of countries of collection from a total of 83 countries, 5,801 instances of building types, and 3,876 instances of surface-air contaminants. The results were implemented in the UNITE database for molecular identification of fungi (http://unite.ut.ee) and were shared with other online resources. Data obtained from human/animal pathogenic fungi will furthermore be verified on culture based metadata for subsequent inclusion in the ISHAM-ITS database (http://its.mycologylab.org).
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| 9. |
- Acosta, Stefan, et al.
(författare)
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Increasing incidence of ruptured abdominal aortic aneurysm : a population-based study
- 2006
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 0741-5214 .- 1097-6809. ; 44:2, s. 237-243
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of the present population-based study was to assess the trends of age- and gender-specific incidence of ruptured abdominal aortic aneurysm (rAAA). Methods. Patients with rAAA from the city of Malmo, Sweden, were studied between 2000 and 2004. An analysis of trends of incidence and mortality of rAAA in Malmo was possible because of a previous population-based study on patients with rAAA between 1971 and 1986 (autopsy rate 85% compared with 25% for the time period 2000 to 2004). The in-hospital registry of Malmo University Hospital and the databases at the Department of Pathology, Malmo, and the Institution of Forensic Medicine, Lund, identified patients with rAAA, and the in-hospital registry identified all elective repairs for AAA. Results. Compared with the time period 1971 to 1986, the overall incidence of rAAA significantly increased from 5.6 (95 % confidence interval [CI], 4.9 to 6.3) to 10.6 (95% CI, 8.9 to 12.4) per 100,000 person-years (standardized mortality ratio, 1.6; 95% CI, 1.0 to 2.1). In men aged 60 to 69 and 70 to 79 years, the incidence increased significantly from 16 (95% CI, 11 to 21) and 56 (95% Cl, 43 to 69) to 46 (95% Cl, 28 to 63) and 117 (95% CI, 84 to 149) per 100,000 person-years, respectively, whereas no increase in the age-specific incidence in women could be demonstrated. The overall incidence of elective repair of AAA increased significantly from 3.4 (95% CI, 2.8 to 4.0) to 7.0 (95% CI, 5.6 to 8.4) per 100,000 person-years and increased most significantly from 12 (95% CI, 3.4 to 32) to 68 (95% CI, 34 to 102) per 100,000 person-years in men aged 80 to 89 years and from 5.1 (95% CI, 2.4 to 9.3) to 28 (95% CI, 15 to 41) per 100,000 person-years in women aged 70 to 79 years. The elective-acute repair ratio in women increased from 2.4 to 5.6 and decreased in men from 2.1 to 1.0. Conclusions: Between 1971 to 1986 and 2000 to 2004, the incidence of rAAA increased significantly, despite a 100% increase in elective repairs and notwithstanding a potential for bias towards underestimation due to lower autopsy rates in recent years. The reason behind this increase is unclear, and further studies are needed to identify risk groups for direction of effective prevention and screening.
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