| 1. |
- 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
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Ingår i: Swedish Production Symposium 2016 SPS 2016. - Lund, Sweden.
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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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| 2. |
- Andersson, Roy, et al.
(författare)
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Similarities and differences between TQM, six sigma and lean
- 2006
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Ingår i: TQM Magazine. - : Emerald. - 0954-478X .- 1758-6887. ; 18:3, s. 282-296
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Purpose – During the last decades, different quality management concepts, including total quality management (TQM), six sigma and lean, have been applied by many different organisations. Although much important work has been documented regarding TQM, six sigma and lean, a number of questions remain concerning the applicability of these concepts in various organisations and contexts. Hence, the purpose of this paper is to describe the similarities and differences between the concepts, including an evaluation and criticism of each concept.Design/methodology/approach – Within a case study, a literature review and face‐to‐face interviews in typical TQM, six sigma and lean organisations have been carried out.Findings – While TQM, six sigma and lean have many similarities, especially concerning origin, methodologies, tools and effects, they differ in some areas, in particular concerning the main theory, approach and the main criticism. The lean concept is slightly different from TQM and six sigma. However, there is a lot to gain if organisations are able to combine these three concepts, as they are complementary. Six sigma and lean are excellent road‐maps, which could be used one by one or combined, together with the values in TQM.Originality/value – The paper provides guidance to organisations regarding the applicability and properties of quality concepts. Organisations need to work continuously with customer‐orientated activities in order to survive; irrespective of how these activities are labelled. The paper will also serve as a basis for further research in this area, focusing on practical experience of these concepts.
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| 3. |
- Bergman, Per, 1960, et al.
(författare)
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Emission from HCN and CH3OH in comets Onsala 20-m observations and radiative transfer modelling
- 2022
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 660
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Tidskriftsartikel (refereegranskat)abstract
- Aims. The aim of this work is to characterise HCN and CH3OH emission from recent comets. Methods. We used the Onsala 20-m telescope to search for millimetre transitions of HCN towards a sample of 11 recent and mostly bright comets in the period from December 2016 to November 2019. Also, CH3OH was searched for in two comets. The HCN sample includes the interstellar comet 2I/Borisov. For the short-period comet 46P/Wirtanen, we were able to monitor the variation of HCN emission over a time-span of about one month. We performed radiative transfer modelling for the observed molecular emission by also including time-dependent effects due to the outgassing of molecules. Results. HCN was detected in six comets. Two of these are short-period comets and four are long-period. Six methanol transitions were detected in 46P/Wirtanen, enabling us to determine the gas kinetic temperature. From the observations, we determined the molecular production rates using time-dependent radiative transfer modelling. For five comets, we were able to determine that the HCN mixing ratios lie near 0.1% using contemporary water production rates, Q(H2O), taken from other studies. This HCN mixing ratio was also found to be typical in our monitoring observations of 46P/Wirtanen but here we notice deviations of up to 0.2% on a daily timescale which could indicate short-time changes in outgassing activity. From our radiative transfer modelling of cometary comae, we find that time-dependent effects on the HCN level populations are of the order of 5-15% when Q(H2O) is around 2 x 10(28) mol s(-1). The effects may be stronger for comets with lower Q(H2O). The exact details of the time-dependent effects depend on the amount of neutral and electron collisions, radiative pumping, and molecular parameters such as the spontaneous rate coefficient.
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| 4. |
- Li, Jingmei, et al.
(författare)
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Prevalence of BRCA1 and BRCA2 pathogenic variants in a large, unselected breast cancer cohort
- 2019
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 144:5, s. 1195-1204
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancer patients with BRCA1/2-driven tumors may benefit from targeted therapy. It is not clear whether current BRCA screening guidelines are effective at identifying these patients. The purpose of our study was to evaluate the prevalence of inherited BRCA1/2 pathogenic variants in a large, clinically representative breast cancer cohort and to estimate the proportion of BRCA1/2 carriers not detected by selectively screening individuals with the highest probability of being carriers according to current clinical guidelines. The study included 5,122 unselected Swedish breast cancer patients diagnosed from 2001 to 2008. Target sequence enrichment (48.48 Fluidigm Access Arrays) and sequencing were performed (Illumina Hi-Seq 2,500 instrument, v4 chemistry). Differences in patient and tumor characteristics of BRCA1/2 carriers who were already identified as part of clinical BRCA1/2 testing routines and additional BRCA1/2 carriers found by sequencing the entire study population were compared using logistic regression models. Ninety-two of 5,099 patients with valid variant calls were identified as BRCA1/2 carriers by screening all study participants (1.8%). Only 416 study participants (8.2%) were screened as part of clinical practice, but this identified 35 out of 92 carriers (38.0%). Clinically identified carriers were younger, less likely postmenopausal and more likely to be associated with familiar ovarian cancer compared to the additional carriers identified by screening all patients. More BRCA2 (34/42, 81.0%) than BRCA1 carriers (23/50, 46%) were missed by clinical screening. In conclusion, BRCA1/2 mutation prevalence in unselected breast cancer patients was 1.8%. Six in ten BRCA carriers were not detected by selective clinical screening of individuals.
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| 5. |
- Nylund, Gustav, et al.
(författare)
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Transparently Wrap-Gated Semiconductor Nanowire Arrays For Studies Of Gate-Controlled Photoluminescence
- 2013
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Ingår i: Physics of Semiconductors. - : AIP. - 0094-243X .- 1551-7616. ; 1566, s. 427-428
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Konferensbidrag (refereegranskat)abstract
- We present a technique to measure gate-controlled photoluminescence (PL) on arrays of semiconductor nanowire (NW) capacitors using a transparent film of Indium-Tin-Oxide (ITO) wrapping around the nanowires as the gate electrode. By tuning the wrap-gate voltage, it is possible to increase the PL peak intensity of an array of undoped InP NWs by more than an order of magnitude. The fine structure of the PL spectrum reveals three subpeaks whose relative peak intensities change with gate voltage. We interpret this as gate-controlled state-filling of luminescing quantum dot segments formed by zincblende stacking faults in the mainly wurtzite NW crystal structure.
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