| 43521. |
- Simonsson, Peter, et al.
(författare)
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'Learning to see' the effects of improved workflow in civil engineering projects
- 2012
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Ingår i: Lean Construction Journal. - 1555-1369. ; , s. 35-48
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Tidskriftsartikel (refereegranskat)abstract
- Research Question/Hypothesis: Value Stream Mapping (VSM) can, independent of work repetition, improve the performance of civil engineering projects by allowing the site management to visualize the flows of materials, resources and information.Purpose: The purpose is to show how VSM can be used by on-site practitioners to see the day-to-day flow of work, to understand the effect of straight-forward improvements to workflow, and to see the effect of applying industrialized working methods.Research Method: Applicability of VSM to civil engineering is examined through the fixing of reinforcement in two bridge construction projects. A traditional bridge was used to map (current state) and improve (future state) workflow. The potential of modern production methods are then analyzed in a second bridge project (ideal state).Findings: Allowing the site management to visualize and to see workflow improves the work performance of the two studied bridges. Addition of easy to understand and calculable metrics for lead time, inventory level and manufacturing costs, emphasize the potential savings of reactive and proactive workflow measures (≈ 80-90 %).Limitations: The paper considers fixing of reinforcement in two bridge construction projects. Additionally, the so-called future state bridge was not actually constructed, i.e. the savings stated for the future state, even if reasonable, are an approximation.Implications: The framework to visualize current, future and ideal workflow provides a framework to extend the VSM methodology to civil engineering projects.Value for practitioners: To overcome the sub-optimized mindset in civil engineering that repeatedly leads to the same practice, the paper proposes a straightforward and easy to use framework to visualize and analyze effects of workflow improvements.
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| 43522. |
- Simonsson, Peter, et al.
(författare)
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Lönsamt att industrialisera och effektivisera brobygge
- 2008
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Ingår i: Husbyggaren : bygg, el, VVS, anläggning. - 0018-7968. ; :2, s. 22-28
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Om bygget av en bro projekteras i ett tidigt skede och sedan sker med nya arbetsmetoder kan brobygget bli en fjärdedel billigare. Samtidigt minskar tunga lyft för byggarna. Det är lönsamt att använda Lean-filosofins sätt att tänka långsiktigt.
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| 43523. |
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| 43524. |
- Simpson, Timothy W., et al.
(författare)
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Platform-based design and development : Current trends and needs in industry
- 2006
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Ingår i: Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference - 2006. - New York, : American Society of Mechanical Engineers. ; , s. 801-810
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Konferensbidrag (refereegranskat)abstract
- Many companies constantly struggle to find cost-effective solutions to satisfy the diverse demands of their customers. In this paper, we report on two recent industry-focused conferences that emphasized platform design, development, and deployment as a means to increase variety, shorten lead-times, and reduce development and production costs. The first conference, Platform Management for Continued Growth, was held November-December 2004 in Atlanta, Georgia, and the second, 2005 Innovations in Product Development Conference - Product Families and Platforms: From Strategic Innovation to Implementation, was held in November 2005 in Cambridge, Massachusetts. The two conferences featured presentations from academia and more than 20 companies who shared their successes and frustrations with platform design and deployment, platform-based product development, and product family planning. Our intent is to provide a summary of the common themes that we observed in these two conferences. Based on this discussion, we extrapolate upon industry's needs in platform design, development, and deployment to stimulate and catalyze future work in this important area of research.
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| 43525. |
- Šimsová née Zámečníková, Martina, et al.
(författare)
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Non-adiabatic dynamics in collisions of sodium and chlorine atoms and their ions
- 2022
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry. - 1463-9076 .- 1463-9084. ; 24:41, s. 25250-25257
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Tidskriftsartikel (refereegranskat)abstract
- Collisions of sodium and chlorine atoms and of their ions are studied within the diabatic two-state picture at energies below and above the ionic threshold with focus on the processes of radiative association, chemiionisation, and mutual neutralisation. The radiative-association cross sections as functions of collision energy are calculated up to 4.6 eV in the case of neutral atoms and up to 3.12 eV in the case of ions. The non-radiative charge-exchange cross sections as functions of collision energy are calculated up to 12 eV for chemiionisation and up to 10.52 eV for mutual neutralisation. The corresponding radiative-association rate coefficients are then determined up to 5300 K for the radiative association of neutral atoms and non-radiative charge-exchange and up to 3615 K for the radiative association of ions. Contribution of many Fano–Feshbach-type resonances is included to the rate coefficient of neutral-atom radiative association. The chemiionisation rate coefficients were calculated from 1000 K to 5300 K. The process of mutual neutralisation exhibits the largest cross sections and also the largest rate coefficients with values around 10−9 cm3 s−1 at all calculated temperatures, 120–5300 K.
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| 43526. |
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| 43527. |
- Šimsová-Zámečníková, Martina, et al.
(författare)
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Formation of NaCl by radiative association in interstellar environments
- 2022
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 664
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Tidskriftsartikel (refereegranskat)abstract
- Context. Radiative association is a possible way of sodium chloride (NaCl) formation in interstellar and related environments. Theoretical studies are essential since laboratory experiments are unavailable and difficult to perform.Aims. The total rate coefficient was calculated for the formation of NaCl by radiative association at 30–750 K.Methods. We included two contributing processes for the total rate-coefficient computation. One of them takes the nonadiabatic coupling between the two lowest 1Σ+ states, Χ1Σ+ and Β1Σ+, into account. The other one was calculated conventionally as a single channel and started in the continuum of the A1Π state. The individual rate coefficients were calculated from cross sections obtained up to 0.8 eV, which enabled us to calculate the rate coefficients up to 750 K. The cross section was also calculated for a one-state process within the Χ1 Σ+ state.Results. The nonadiabatic coupling enhances the formation of NaCl by radiative association by two orders of magnitude at about 30 K and by around one order of magnitude at about 750 K. The single-channel process starting in the continuum of the A1 Π state starts to contribute above around 200 K. The one-state transition model, within the Χ1Σ+ state, is not an adequate approximation for collisions in 1Σ+ symmetry. Instead, these collisions are treated in the diabatic representation in the total rate-coefficient calculation.Conclusions. The calculated total rate-coefficient function at 30–750 K can improve the astrochemical reaction networks for the CRL 2688, IRC+10216, and Orion SrcI environments, where NaCl was detected before.
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| 43528. |
- Simu, Kajsa, et al.
(författare)
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A test platform of viable methods to improve production and learning on construction sites
- 2019
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Ingår i: Emerald Reach Proceedings Series. - : Emerald Group Publishing Limited. - 2516-2853. ; 2, s. 481-487
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Purpose - A comprehensive intervention test platform, Valla Coach, including quantitative and qualitative methods to measure and improve work flows on site and promote coaching and collective learning has been developed jointly by researchers and practitioner. The study aims to describe the methodological underpinning of the platform, and discusses the preliminary results and implications. Design/Methodology/Approach - Expansive Learning Theory grounded in a cultural-historical perspective underpins the conceptual realisation of the test platform. The viability of the platform was tested in four contextually different construction sites (and contractors), combining established and new measurement tools, qualitative intervention approaches and coaching according to the production challenges at hand. Findings - Valla Coach created a space on site where researchers-as-coaches and operatives converged to co-construct (new) knowledge and learn together. The knowledge that emerged from the interactions gained legitimacy through its situatedness and practical value for the operatives. Research Limitations/Implications - Valla Coach provides opportunities for researchers and practitioners to probe the taken-for-granted. Moreover, a variety of methods and tools are tested in different contexts. The interventions prompt questioning of assumptions and make contradictions visible. Valla Coach remains work-in-progress and needs further evaluation and validation. Practical Implications - We contribute insights from negotiating socio-technical complexities, evaluating digital measurement tools and technologies and experiences of operatives. Tensions at the interface between the organisation and project are rendered visible. Originality/Value - A bottom-up approach that is a combination of practice-based tools and methods and of theories of learning and sustainable and continuous improvements where the operators are the main actors that enable productive activity.
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| 43529. |
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| 43530. |
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