1,105 research outputs found

    Towards a lean model for production management of refurbishment projects, VTT Technology: 94

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    This is the Stage 3 Report for the ApRemodel project, which aims at improving processes for multi-occupancy retrofit by generating a lean model for project delivery. In this respect, a process-driven approach has been adopted to investigate what can be done to improve the way that retrofits projects are delivered. An initial literature review, focused on the management of refurbishment works, revealed that the research on this matter is scarce. There are plenty of studies related to the broad refurbishment area, however only a small number refer to the way that those construction projects are delivered. According to the literature, construction organisations have predominantly used traditional methods for managing the production of refurbishment projects. The problem is that those tools and techniques are not often appropriate to cope with the complex characteristics inherent to construction projects, especially in the case of refurbishments. Moreover, they have often not been based on a clear theoretical foundation. As a result, numerous types of waste have been identified in refurbishment projects such as waiting time, disruptions in performing tasks on site, rework, among others. This has led to unsatisfactory project performance in terms of low productivity, project delays, and cost overrun. The first step towards better production management in refurbishment projects is recognising the complexity of the sector in order to adopt the correct approach to cope with this specific scenario. In this respect, lean construction is identified as an appropriate way to deal with the complexity and uncertainty inherent in refurbishment projects, given that this management philosophy fully integrates the conversion, flow, and value views. This document builds on the findings from the literature review as well as evidence from case studies. Managerial practices based on lean construction principles have presented successful results in the management of complex projects. Case studies available in the literature report the feasibility and usefulness of this theoretical foundation. Moreover, the evidence from these studies show considerable potential for improving the management of refurbishment works. A list of methods, tools, and techniques are identified. This report may be used by construction refurbishment organisations and housing associations as a starting point for improving the efficiency in managing production of refurbishment projects. To this end, partnerships between industry and academia are strongly recommended. 4 Although the usefulness of lean principles in complex projects is already proved, further work is needed to check what practices are best for the respective refurbishment context, as well as identifying enablers and barriers for practical adoption. Furthermore, additional studies would be also necessary to better understand the extent to which the implementation of lean philosophy might influence performance of refurbishment projects. This report should be seen as work in progress with much more to learn, as detailed research work around the sustainable retrofit process in a lean way is further developed

    Towards a lean model for production management of refurbishment projects

    Get PDF
    This is the Stage 3 Report for the ApRemodel project, which aims at improving processes for multi-occupancy retrofit by generating a lean model for project delivery. In this respect, a process-driven approach has been adopted to investigate what can be done to improve the way that retrofits projects are delivered. An initial literature review, focused on the management of refurbishment works, revealed that the research on this matter is scarce. There are plenty of studies related to the broad refurbishment area, however only a small number refer to the way that those construction projects are delivered. According to the literature, construction organisations have predominantly used traditional methods for managing the production of refurbishment projects. The problem is that those tools and techniques are not often appropriate to cope with the complex characteristics inherent to construction projects, especially in the case of refurbishments. Moreover, they have often not been based on a clear theoretical foundation. As a result, numerous types of waste have been identified in refurbishment projects such as waiting time, disruptions in performing tasks on site, rework, among others. This has led to unsatisfactory project performance in terms of low productivity, project delays, and cost overrun. The first step towards better production management in refurbishment projects is recognising the complexity of the sector in order to adopt the correct approach to cope with this specific scenario. In this respect, lean construction is identified as an appropriate way to deal with the complexity and uncertainty inherent in refurbishment projects, given that this management philosophy fully integrates the conversion, flow, and value views. This document builds on the findings from the literature review as well as evidence from case studies. Managerial practices based on lean construction principles have presented successful results in the management of complex projects. Case studies available in the literature report the feasibility and usefulness of this theoretical foundation. Moreover, the evidence from these studies show considerable potential for improving the management of refurbishment works. A list of methods, tools, and techniques are identified. This report may be used by construction refurbishment organisations and housing associations as a starting point for improving the efficiency in managing production of refurbishment projects. To this end, partnerships between industry and academia are strongly recommended. 4 Although the usefulness of lean principles in complex projects is already proved, further work is needed to check what practices are best for the respective refurbishment context, as well as identifying enablers and barriers for practical adoption. Furthermore, additional studies would be also necessary to better understand the extent to which the implementation of lean philosophy might influence performance of refurbishment projects. This report should be seen as work in progress with much more to learn, as detailed research work around the sustainable retrofit process in a lean way is further develope

    Dog–Owner Relationship, Owner Interpretations and Dog Personality Are Connected with the Emotional Reactivity of Dogs

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    We evaluated the effect of the dog–owner relationship on dogs’ emotional reactivity, quantified with heart rate variability (HRV), behavioral changes, physical activity and dog owner interpretations. Twenty nine adult dogs encountered five different emotional situations (i.e., stroking, a feeding toy, separation from the owner, reunion with the owner, a sudden appearance of a novel object). The results showed that both negative and positive situations provoked signs of heightened arousal in dogs. During negative situations, owners’ ratings about the heightened emotional arousal correlated with lower HRV, higher physical activity and more behaviors that typically index arousal and fear. The three factors of The Monash Dog–Owner Relationship Scale (MDORS) were reflected in the dogs’ heart rate variability and behaviors: the Emotional Closeness factor was related to increased HRV (p = 0.009), suggesting this aspect is associated with the secure base effect, and the Shared Activities factor showed a trend toward lower HRV (p = 0.067) along with more owner-directed behaviors reflecting attachment related arousal. In contrast, the Perceived Costs factor was related to higher HRV (p = 0.009) along with less fear and less owner-directed behaviors, which may reflect the dog’s more independent personality. In conclusion, dogs’ emotional reactivity and the dog–owner relationship modulate each other, depending on the aspect of the relationship and dogs’ individual responsivity

    Dog–Owner Relationship, Owner Interpretations and Dog Personality Are Connected with the Emotional Reactivity of Dogs

    Get PDF
    We evaluated the effect of the dog–owner relationship on dogs’ emotional reactivity, quantified with heart rate variability (HRV), behavioral changes, physical activity and dog owner interpretations. Twenty nine adult dogs encountered five different emotional situations (i.e., stroking, a feeding toy, separation from the owner, reunion with the owner, a sudden appearance of a novel object). The results showed that both negative and positive situations provoked signs of heightened arousal in dogs. During negative situations, owners’ ratings about the heightened emotional arousal correlated with lower HRV, higher physical activity and more behaviors that typically index arousal and fear. The three factors of The Monash Dog–Owner Relationship Scale (MDORS) were reflected in the dogs’ heart rate variability and behaviors: the Emotional Closeness factor was related to increased HRV (p = 0.009), suggesting this aspect is associated with the secure base effect, and the Shared Activities factor showed a trend toward lower HRV (p = 0.067) along with more owner-directed behaviors reflecting attachment related arousal. In contrast, the Perceived Costs factor was related to higher HRV (p = 0.009) along with less fear and less owner-directed behaviors, which may reflect the dog’s more independent personality. In conclusion, dogs’ emotional reactivity and the dog–owner relationship modulate each other, depending on the aspect of the relationship and dogs’ individual responsivity

    Temperature dependence of the Brewer global UV measurements

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    Spectral measurements of global UV irradiance recorded by Brewer spectrophotometers can be significantly affected by instrument-specific optical and mechanical features. Thus, proper corrections are needed in order to reduce the associated uncertainties to within acceptable levels. The present study aims to contribute to the reduction of uncertainties originating from changes in the Brewer internal temperature, which affect the performance of the optical and electronic parts, and subsequently the response of the instrument. Until now, measurements of the irradiance from various types of lamps at different temperatures have been used to characterize the instruments' temperature dependence. The use of 50 W lamps was found to induce errors in the characterization due to changes in the transmissivity of the Teflon diffuser as it warms up by the heat of the lamp. In contrast, the use of 200 or 1000 W lamps is considered more appropriate because they are positioned at longer distances from the diffuser so that warming is negligible. Temperature gradients inside the instrument can cause mechanical stresses which can affect the instrument's optical characteristics. Therefore, during the temperature-dependence characterization procedure warming or cooling must be slow enough to minimize these effects. In this study, results of the temperature characterization of eight different Brewer spectrophotometers operating in Greece, Finland, Germany and Spain are presented. It was found that the instruments' response changes differently in different temperature regions due to different responses of the diffusers' transmittance. The temperature correction factors derived for the Brewer spectrophotometers operating at Thessaloniki, Greece, and SodankylĂ€, Finland, were evaluated and were found to remove the temperature dependence of the instruments' sensitivity.This article is based upon work from COST Action ES1207 “A European Brewer Network (EUBREWNET)”, supported by COST (European Cooperation in Science and Technology) and from the ENV59-ATMOZ (“Traceability for atmospheric total column ozone”) Joint Research Programme (JRP)

    Attenuated Semliki Forest virus for cancer treatment in dogs : safety assessment in two laboratory Beagles

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    Background: Dogs suffer from spontaneous tumors which may be amenable to therapies developed for human cancer patients, and dogs may serve as large-animal cancer models. A non-pathogenic Semliki Forest virus vector VA7-EGFP previously showed promise in targeting human tumor xenografts in mice, but the oncolytic capacity of the virus in canine cancer cells and the safety of the virus in higher mammals such as dogs, are not known. We therefore assessed the oncolytic potency of VA7-EGFP against canine cancer cells by infectivity and viability assays in two dog solid tumor cell lines. Furthermore we performed a 3-week safety study in two adult Beagles which received a single intravenous injection of similar to 2 x 10(5) plaque forming units of parental A7(74) strain. Results: VA7-EGFP was able to replicate in and kill both canine cancer cell lines tested. No adverse events were observed in either of the two virus-injected adult Beagles and no infective virus could be recovered from any of the biological samples collected over the course of the study. Neutralizing antibodies to Semliki Forest virus became detectable in the dogs at 5 days post infection and remained elevated until study termination. Conclusions: Based on these results, testing of the oncolytic potential of attenuated Semliki Forest virus in canine cancer patients appears feasible.Peer reviewe

    Fractional differentiability for solutions of nonlinear elliptic equations

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    We study nonlinear elliptic equations in divergence form div⁥A(x,Du)=div⁥G.{\operatorname{div}}{\mathcal A}(x,Du)={\operatorname{div}}G. When A{\mathcal A} has linear growth in DuDu, and assuming that x↩A(x,Ο)x\mapsto{\mathcal A}(x,\xi) enjoys Bnα,qαB^\alpha_{\frac{n}\alpha, q} smoothness, local well-posedness is found in Bp,qαB^\alpha_{p,q} for certain values of p∈[2,nα)p\in[2,\frac{n}{\alpha}) and q∈[1,∞]q\in[1,\infty]. In the particular case A(x,Ο)=A(x)Ο{\mathcal A}(x,\xi)=A(x)\xi, G=0G=0 and A∈Bnα,qαA\in B^\alpha_{\frac{n}\alpha,q}, 1≀q≀∞1\leq q\leq\infty, we obtain Du∈Bp,qαDu\in B^\alpha_{p,q} for each p<nαp<\frac{n}\alpha. Our main tool in the proof is a more general result, that holds also if A{\mathcal A} has growth s−1s-1 in DuDu, 2≀s≀n2\leq s\leq n, and asserts local well-posedness in LqL^q for each q>sq>s, provided that x↩A(x,Ο)x\mapsto{\mathcal A}(x,\xi) satisfies a locally uniform VMOVMO condition

    Effect of plasma response on the fast ion losses due to ELM control coils in ITER

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    Mitigating edge localized modes (ELMs) with resonant magnetic perturbations (RMPs) can increase energetic particle losses and resulting wall loads, which have previously been studied in the vacuum approximation. This paper presents recent results of fusion alpha and NBI ion losses in the ITER baseline scenario modelled with the Monte Carlo orbit following code ASCOT in a realistic magnetic field including the effect of the plasma response. The response was found to reduce alpha particle losses but increase NBI losses, with up to 4.2% of the injected power being lost. Additionally, some of the load in the divertor was found to be shifted away from the target plates toward the divertor dome

    Fractional Sobolev-Poincaré inequalities in irregular domains

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    This paper is devoted to the study of fractional (q, p)-Sobolev-PoincarĂ© in- equalities in irregular domains. In particular, the author establishes (essentially) sharp fractional (q, p)-Sobolev-PoincarĂ© inequalities in s-John domains and in domains satisfying the quasihyperbolic boundary conditions. When the order of the fractional derivative tends to 1, our results tend to the results for the usual derivatives. Furthermore, the author verifies that those domains which support the fractional (q, p)-Sobolev-PoincarĂ© inequalities together with a separation property are s-diam John domains for certain s, depending only on the associated data. An inaccurate statement in [Buckley, S. and Koskela, P., Sobolev-PoincarĂ© implies John, Math. Res. Lett., 2(5), 1995, 577–593] is also pointed out
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