256 research outputs found

    A framework for smart production-logistics systems based on CPS and industrial IoT

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    Industrial Internet of Things (IIoT) has received increasing attention from both academia and industry. However, several challenges including excessively long waiting time and a serious waste of energy still exist in the IIoT-based integration between production and logistics in job shops. To address these challenges, a framework depicting the mechanism and methodology of smart production-logistics systems is proposed to implement intelligent modeling of key manufacturing resources and investigate self-organizing configuration mechanisms. A data-driven model based on analytical target cascading is developed to implement the self-organizing configuration. A case study based on a Chinese engine manufacturer is presented to validate the feasibility and evaluate the performance of the proposed framework and the developed method. The results show that the manufacturing time and the energy consumption are reduced and the computing time is reasonable. This paper potentially enables manufacturers to deploy IIoT-based applications and improve the efficiency of production-logistics systems

    The sums of the reciprocals of Fibonacci polynomials and Lucas polynomials

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    On the road to digital servitization : The (dis)continuous interplay between business model and digital technology

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    Purpose The authors seek to understand the process of digital servitization as a shift of manufacturing companies from the provision of standard products and services to smart solutions. Specifically, the authors focus on changes in the business model (i.e. the value proposition, the value delivery system and the value capture mechanism) for digital servitization. Design/methodology/approach The authors examine a Chinese air conditioner manufacturer, Gree, who became the global leader with their smart solutions. These solutions included performance-based contracts underpinned by artificial intelligence (AI)-powered air conditioners that automatically adjust to environmental changes and are capable of remote monitoring and servicing thanks to its Internet of things (IoT) technology. Findings To successfully offer smart solution value propositions, a manufacturer needs an ecosystem value delivery system composed of suppliers, distributors, partners and customers. Once the ecosystem relationships are well aligned, the manufacturer gains value with multiple value capture mechanisms (i.e. efficiency, accountability, shared customer value and novelty). To arrive at this point, a manufacturer has to pass through different stages that are characterized by both discontinuous and continuous interplay between business models and digital technologies. At the beginning of each stage, new value propositions and value delivery systems are first discontinuously created and then enabled with digital technology. As a result, new value capture mechanisms are activated. Meanwhile, the elements of the existing business model are continuously improved. Research limitations/implications By combining process-perspective and business-model lenses, the authors offer nuanced insights into how digital servitization unfolds. Practical implications Executives can obtain insights into the business model elements, they need to change over the course of digital servitization and how to manage the process. Originality/value A longitudinal case study of a traditional manufacturer that has achieved stellar success through digital servitization business models development.© Yihua Chen, Ivanka Visnjic, Vinit Parida and Zhengang Zhang. Published by Emerald Publishing Limited. This article is published under the Creative Commons Attribution (CC BY 4.0) licence. Anyone may reproduce, distribute, translate and create derivative works of this article (for both commercial and non-commercial purposes), subject to full attribution to the original publication and authors. The full terms of this licence may be seen at http://creativecommons.org/licences/by/4.0/legalcodeThe authors gratefully acknowledge the help and excellent comments provided by the International Journal of Operations & Production Management editorial team and Servitization 2.0 Special IssueEditors: Rodrigo Rabetino, Marko Kohtamäki, Christian Kowalkowski, Tim S. Baines and Rui Sousa. Yihua Chen and Zhengang Zhang acknowledge financial support from the Major Project of National Social Science Fund of China (No. 18ZDA062). Ivanka Visnjic acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities, Reference: PGC2018-2010;101022-A-100“SERSISTEMICS”. Vinit Parida acknowledges financial support from Vinnova and PiiA Process Industrial IT and Automation. The authors are also very grateful for the insightful and constructive comments from the anonymous reviewers.fi=vertaisarvioitu|en=peerReviewed

    Transparent Perfect Microwave Absorber Employing Asymmetric Resonance Cavity

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    The demand for high‐performance absorbers in the microwave frequencies, which can reduce undesirable radiation that interferes with electronic system operation, has attracted increasing interest in recent years. However, most devices implemented so far are opaque, limiting their use in optical applications that require high visible transparency. Here, a scheme is demonstrated for microwave absorbers featuring high transparency in the visible range, near‐unity absorption (≈99.5% absorption at 13.75 GHz with 3.6 GHz effective bandwidth) in the Ku‐band, and hence excellent electromagnetic interference shielding performance (≈26 dB). The device is based on an asymmetric Fabry–Pérot cavity, which incorporates a monolayer graphene and a transparent ultrathin (8 nm) doped silver layer as absorber and reflector, and fused silica as the middle dielectric layer. Guided by derived formulism, this asymmetric cavity is demonstrated with microwaves near‐perfectly and exclusively absorbs in the ultrathin graphene film. The peak absorption frequency of the cavity can be readily tuned by simply changing the thickness of the dielectric spacer. The approach provides a viable solution for a new type of microwave absorber with high visible transmittance, paving the way towards applications in the area of optics.A general strategy is presented to design a new type of microwave absorber based on an asymmetric Fabry–Pérot resonant cavity by employing monolayer graphene, transparent spacer, and ultrathin doped Ag film. This asymmetric cavity is demonstrated with microwaves near‐perfectly and exclusively absorbs in the ultrathin graphene layer at resonances and maintains high visible transmittance.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151816/1/advs1299-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151816/2/advs1299.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151816/3/advs1299_am.pd

    Intraflagellar transporter protein (IFT27), an IFT25 binding partner, is essential for male fertility and spermiogenesis in mice

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    Intraflagellar transport (IFT) is an evolutionarily conserved mechanism essential for the assembly and maintenance of most eukaryotic cilia and flagella. In mice, mutations in IFT proteins have been shown to cause several ciliopathies including retinal degeneration, polycystic kidney disease, and hearing loss. However, little is known about its role in the formation of the sperm tail, which has the longest flagella of mammalian cells. IFT27 is a component of IFT-B complex and binds to IFT25 directly. In mice, IFT27 is highly expressed in the testis. To investigate the role of IFT27 in male germ cells, the floxed Ift27 mice were bred with Stra8-iCre mice so that the Ift27 gene was disrupted in spermatocytes/spermatids. The Ift27: Stra8-iCre mutant mice did not show any gross abnormalities, and all of the mutant mice survived to adulthood. There was no difference between testis weight/body weight between controls and mutant mice. All adult homozygous mutant males examined were completely infertile. Histological examination of the testes revealed abnormally developed germ cells during the spermiogenesis phase. The epididymides contained round bodies of cytoplasm. Sperm number was significantly reduced compared to the controls and only about 2% of them remained significantly reduced motility. Examination of epididymal sperm by light microscopy and SEM revealed multiple morphological abnormalities including round heads, short and bent tails, abnormal thickness of sperm tails in some areas, and swollen tail tips in some sperm. TEM examination of epididymal sperm showed that most sperm lost the 9+2\u27\u27 axoneme structure, and the mitochondria sheath, fibrous sheath, and outer dense fibers were also disorganized. Some sperm flagella also lost cell membrane. Levels of IFT25 and IFT81 were significantly reduced in the testis of the conditional Ift27 knockout mice, and levels of IFT20, IFT74, and IFT140 were not changed. Sperm lipid rafts, which were disrupted in the conditional Ift25 knockout mice, appeared to be normal in the conditional Ift27 knockout mice. Our findings suggest that like IFT25, IFT27, even though not required for ciliogenesis in somatic cells, is essential for sperm flagella formation, sperm function, and male fertility in mice. IFT25 and IFT27 control sperm formation/function through many common mechanisms, but IFT25 has additional roles beyond IFT27

    Effects of Methotrexate on Plasma Cytokines and Cardiac Remodeling and Function in Postmyocarditis Rats

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    Excessive immune activation and inflammatory mediators may play a critical role in the pathogenesis of chronic heart failure. Methotrexate is a commonly used anti-inflammatory and immunosuppressive drug. In this study, we used a rat model of cardiac myosin-induced experimental autoimmune myocarditis to investigate the effects of low-dose methotrexate (0.1 mg/kg/d for 30 d) on the plasma level of cytokines and cardiac remodeling and function. Our study showed that levels of tumor necrosis factor-(TNF-)alpha and interleukin-6 (IL-6) are significantly increased in postmyocarditis rats, compared with the control rats. Methotrexate treatment reduced the plasma levels of TNF-alpha and IL-6 and increased IL-10 level, compared to saline treatment. In addition, postmyocarditis rats showed significant cardiac fibrosis characterized by increased myocardial collagen volume fraction, perivascular collagen area, and the ratio of collagen type I to type III, compared with the control rats. However, MTX treatment not only markedly attenuated cardiac fibrosis, diminished the left ventricular end-diastolic dimension, but also increased the left ventricular ejection fraction and fractional shortening. Collectively, these results suggest that low-dose methotrexate has ability to regulate inflammatory responses and improves cardiac function and hence contributes to prevent the development of postmyocarditis dilated cardiomyopathy
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