406 research outputs found
Automatic generation: A way of ensuring PLC and HMI standards
Preparing an automatic production system takes a lot of time and to be able to decrease this time virtual simulation studies are used more and more frequently. However, even if more work is performed in a virtual environment a problem is still that the same work is done more than one time in different software tools due to the lack of integration between them. The present paper presents a case study that investigates how a newly developed tool called SIMATIC Automation Designer can be used in order to close the gap between the mechanical design and the electrical design. SIMATIC Automation Designer is a Siemens software that can generate PLC code and HMI screens. The result shows that by generating PLC code and HMI screens automatically, it is possible to get the same structure and naming standard in every PLC and HMI project. This will ensure a corporate standard and will be a quality assurance of the PLC code and HMI screens
An evolutionary developmental approach to cultural evolution
Evolutionary developmental theories in biology see the processes and organization of organisms as crucial for understanding the dynamic behavior of organic evolution. Darwinian forces are seen as necessary but not sufficient for explaining observed evolutionary patterns. We here propose that the same arguments apply with even greater force to culture vis-Ă -vis cultural evolution. In order not to argue entirely in the abstract, we demonstrate the proposed approach by combining a set of different models into a provisional synthetic theory, and by applying this theory to a number of short case studies. What emerges is a set of concepts and models that allow us to consider entirely new types of explanations for the evolution of cultures. For example we see how feedback relations - both within societies and between societies and their ecological environment - have the power to shape evolutionary history in profound ways. The ambition here is not to produce a definite statement on what such a theory should look like but rather to propose a starting point along with an argumentation and demonstration of its potential
Modeling the emergence of affective polarization in the social media society
Rising political polarization in recent decades has hampered and gridlocked policymaking, as well as weakened trust in democratic institutions. These developments have been linked to the idea that new media technology fosters extreme views and political conflict by facilitating self-segregation into âecho chambersâ where opinions are isolated and reinforced. This opinion-centered picture has recently been challenged by an emerging political science literature on âaffective polarizationâ, which suggests that current polarization is better understood as driven by partisanship emerging as a strong social identity. Through this lens, politics has become a question of competing social groups rather than differences in policy position. Contrary to the opinion-centered view, this identity-centered perspective has not been subject to dynamical formal modeling, which generally permits hypotheses about micro-level explanations for macro-level phenomena to be systematically tested and explored. We here propose a formal model that links new information technology to affective polarization via social psychological mechanisms of social identity. Our results suggest that new information technology catalyzes affective polarization by lowering search and interaction costs, which shifts the balance between centrifugal and centripetal forces of social identity. We find that the macro-dynamics of social identity is characterized by two stable regimes on the societal level: one fluid regime, in which identities are weak and social connections heterogeneous, and one solid regime in which identities are strong and groups homogeneous. We also find evidence of hysteresis, meaning that a transition into a fragmented state is not readily reversed by again increasing those costs. This suggests that, due to systemic feedback effects, if polarization passes certain tipping points, we may experience run-away political polarization that is highly difficult to reverse
Optimizing optimization for design optimization",
ABSTRACT Design optimization is becoming and increasingly important tool for design. In order to have an impact on the product development process it must permeate all levels of the design in such a way that a holistic view is maintained through all stages of the design. One important area is in the case of optimization based on simulation, which generally requires non-gradient methods and as a consequence directsearch methods is a natural choice. The idea in this paper is to use the design optimization approach in the optimization algorithm itself in order to produce an efficient and robust optimization algorithm. The result is a single performance index to measure the effectiveness of an optimization algorithm, and the COMPLEX-RF optimization algorithm, with optimized parameters
Coldings tool life model applied on tool wear when machining the Maxthal material
Coldings tool life equation for metal cutting tools has been modified to suit the difficult to machine material Maxthal. The dominant tool wear mechanisms during machining of Maxthal are abrasive and adhesive wear and a strongly temperature dependent chemical deterioration. The combination of these three mechanisms leads to a considerable variation in tool life, even when the cutting speed has been varied in a relatively close range. Metal cutting experiments has been carried out as straight turning, were the wear level of the tool has been monitored by cutting force measurement. Sample tests have been performed with 3 different insert types. The results show that the best cutting conditions are obtained with a cermet insert. The difference in tool life and total cutting capacity between the studied insert types is ca 10%. The experimental data has been adapted to Coldings tool life model. Within the cutting data interval 25<vc<50 m/min, Coldings model can suggest a cutting speed for a total tool life of 7 minutes with an average accuracy better than 10%. For carbide inserts, maximum chip vol-ume flow is obtain for a fixed value of the equivalent chip thickness he, for a given tool life
Dynamic lifecycle cost modeling for adaptable design optimization of additively remanufactured aeroengine components
Additive manufacturing (AM) is being used increasingly for repair and remanufacturing of aeroengine components. This enables the consideration of a design margin approach to satisfy changing requirements, in which component lifespan can be optimized for different lifecycle scenarios. This paradigm requires lifecycle cost (LCC) modeling; however, the LCC models available in the literature consider mostly the manufacturing of a component, not its repair or remanufacturing. There is thus a need for an LCC model that can consider AM for repair/remanufacturing to quantify corresponding costs and benefits. This paper presents a dynamic LCC model that estimates cumulative costs over the in-service phase and a nested design optimization problem formulation that determines the optimal component lifespan range to minimize overall cost while maximizing performance. The developed methodology is demonstrated by means of an aeroengine turbine rear structure
Fama-Frenchs trefaktormodell och CAPM
I den hĂ€r uppsatsen testas Fama-Frenchs trefaktormodell och âCapital Asset Pricing Modelâ för att jĂ€mföra vilken av modellerna som bĂ€st förklarar avkastningen pĂ„ OMX-Stockholmsbörsen. Aktiedata frĂ„n ett urval av Large cap och Small cap aktier analyseras under Ă„ren 2010-2015. Hur vĂ€l modellerna fungerar avgörs med en regressionsanalys, dĂ€r riskpremierna RMRF, SMB och HML studeras. RMRF blev genomgĂ„ende positivt signifikant medan varken SMB eller HML var sĂ€rskilt relevanta för att förklara avkastningen. Resultatet tyder pĂ„ att trefaktormodellen förklarar avkastningen i lika hög utstrĂ€ckning som CAPM men eftersom trefaktormodellen anvĂ€nder ytterligare tvĂ„ variabler skulle modellen kunna betraktas som överflödig. Slutsatsen blir att en passiv investeringsstrategi, likt CAPM, Ă€r att föredra framför en aktiv investeringsstrategi som utgĂ„r ifrĂ„n Fama-Frenchs trefaktormodell
Toward a Macroevolutionary Theory of Human Evolution: The Social Protocell
Despite remarkable empirical and methodological advances, our theoretical understanding of the evolutionary processes that made us human remains fragmented and contentious. Here, we make the radical proposition that the cultural communities within which\ua0Homo\ua0emerged may be understood as a novel exotic form of organism. The argument begins from a deep congruence between robust features of\ua0Pan\ua0community life cycles and protocell models of the origins of life. We argue that if a cultural tradition, meeting certain requirements, arises in the context of such a âsocial protocell,â the outcome will be an evolutionary transition in individuality whereby traditions and hominins coalesce into a macroscopic bio-socio-technical system, with an organismal organization that is culturally inherited through irreversible fission events on the community level. We refer to the resulting hypothetical evolutionary individual as a âsociont.â The social protocell provides a preadapted source of alignment of fitness interests that addresses a number of open questions about the origins of shared adaptive cultural organization, and the derived genetic (and highly unusual) adaptations that support them. Also, social cooperation between hominins is no longer in exclusive focus since cooperation among traditions becomes salient in this model. This provides novel avenues for explanation. We go on to hypothesize that the fate of the hominin in such a setting would be mutualistic coadaptation into a part-whole relation with the sociont, and we propose that the unusual suite of derived features in\ua0Homo\ua0is consistent with this hypothesis
A similarity-assisted multi-fidelity approach to conceptual design space exploration
In conceptual design studies engineers typically utilize data-based surrogate models to enable rapid evaluation of design objectives that otherwise would be too computationally expensive and time-consuming to simulate. Due to the computationally expensive simulations, the data-based surrogate models are often trained using small sample sizes, resulting in low-fidelity models which can produce results that are not trustworthy. To mitigate this issue, a similarity-assisted design space exploration method is proposed. The similarity is measured between design points that have been evaluated through lower-fidelity data-based surrogate models and design points that have been evaluated using higher-fidelity physics-based simulations. This similarity information can then be used by design engineers to better understand the trustworthiness of the data produced by the low-fidelity surrogate models. Our numerical experiments demonstrate that such a similarity measurement can be used as an indicator of the trustworthiness of the lower-fidelity model predictions. Moreover, a second similarity metric is proposed for measuring the similarity of new designs to legacy designs, thus highlighting the potential to reuse knowledge, analysis models, and data. The proposed method is demonstrated by means of an aero-engine structural component conceptual design study. An open-source software tool developed to assist in data visualization is also presented
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