Showing papers by "Paris West University Nanterre La Défense published in 2019"
TL;DR: The proof-of-concept measurements show that all bi-functional metalenses exhibit two independent functionalities that can be switched by flipping the helicity of the incident illumination, which provides a promising route for the realization of reconfigurable lenses and antennas in wireless communication systems.
Abstract: Regarding miniaturized and integrated systems, a single flat device that possesses diversified functionalities is highly desirable in optical to microwave regimes. With this perspective, bifunctional metalenses constructed by meta-atoms with integrated response to propagation phase and geometric phase are proposed for independent manipulation of right-handed and left-handed circularly polarized waves. The derived general criterion is verified in the microwave region from three bifunctional metalenses operating in transmission manner. The proof-of-concept measurements show that all these metalenses exhibit two independent functionalities that can be switched by flipping the helicity of the incident illumination. Very high efficiencies of around 80%, with peak value of 91%, are achieved by the ultrathin metasurfaces of thickness 0.15λ0. The proposed metasurfaces provide a promising route for the realization of reconfigurable lenses and antennas in wireless communication systems.
159 citations
TL;DR: In this article, the bending, vibration and buckling characteristics of functionally graded porous graphene-reinforced nanocomposite curved beams are studied based on a trigonometric shear deformation theory.
88 citations
TL;DR: A Bayesian meta-analysis of individual patient data from studies investigating the effects of CBM as a behavior change intervention for the treatment of alcohol and tobacco use disorders, in individuals aware of the behavior change goal of the studies indicates the absence of enough evidence in favor or against a reliable effect ofCBM on cognitive bias and relapse rate in alcohol and Tobacco use disorders.
Abstract: Cognitive Bias Modification (CBM) refers to a family of interventions targeting substance-related cognitive biases, which have been found to play a role in the maintenance of addictive behaviors. In this study, we conducted a Bayesian meta-analysis of individual patient data from studies investigating the effects of CBM as a behavior change intervention for the treatment of alcohol and tobacco use disorders, in individuals aware of the behavior change goal of the studies. Main outcomes included reduction in the targeted cognitive biases after the intervention and in substance use or relapse rate at the short-to-long term follow-up. Additional moderators, both at the study-level (type of addiction and CBM training) and at the participant-level (amount of completed training trials, severity of substance use), were progressively included in a series of hierarchical mixed-effects models. We included 14 studies involving 2435 participants. CBM appeared to have a small effect on cognitive bias (0.23, 95% credible interval = 0.06–0.41) and relapse rate (−0.27, 95% credible interval = −0.68 – 0.22), but not on reduction of substance use. Increased training practice showed a paradoxical moderation effect on relapse, with a relatively lower chance of relapse in the control condition with increased practice, compared to the training condition. All effects were associated with extremely wide 95% credible intervals, which indicate the absence of enough evidence in favor or against a reliable effect of CBM on cognitive bias and relapse rate in alcohol and tobacco use disorders. Besides the need for a larger body of evidence, research on the topic would benefit from a stronger adherence to the current methodological standards in randomized controlled trial design and the systematic investigation of shared protocols of CBM.
87 citations
TL;DR: In this article, the structural characteristics of a curved beam, constituting of porous metal foam and graphene platelets as nanofillers for reinforcement, are evaluated considering different dispersion patterns for the graphene and porosity, shallowness of the curved beam and platelet geometry.
Abstract: Here, the investigation of thick functionally graded graphene platelets reinforced porous nanocomposite curved beams is carried out considering the static bending and elastic stability analyses based on a higher-order shear deformation theory accounting for through-thickness stretching effect. The formulation is general through which different theories can be realized for various structural applications of beam. The governing equations are developed using the Hamilton's principle and are solved by introducing the Navier's solutions. The formulation is firstly assessed considering problems for that results are available in the literature. The performance of various theories is compared here for the selected problems. The structural characteristics of curved beam, constituting of porous metal foam and graphene platelets as nanofillers for reinforcement, are evaluated considering different dispersion patterns for the graphene and porosity, shallowness of the curved beam, thickness ratio, and platelet geometry. The deflection and stress variations in the thickness direction of the beam are also examined.
84 citations
TL;DR: In this paper, the authors examine the relationship between corporate governance and corporate sustainability by focusing on two main components of companies' governance structure: boards of directors and investor relations officers (IROs).
Abstract: This paper examines the relationships between corporate governance and corporate sustainability by focusing on two main components of companies’ governance structure: boards of directors (BoDs) and investor relations officers (IROs). We propose an original empirical strategy based on the 120 biggest French capitalizations for the year 2013, allowing us to measure boards of directors’ independence and expertise, as well as investor relations officers’ convictions and communication on corporate sustainability. Our results show that corporate governance has an ambiguous impact on corporate sustainability because of opposing forces: internal, external and intermediate forces. On the one hand, the higher the proportion of inside directors, the higher the company’s environmental and governance performance, while the higher the proportion of general experts in the board room, the lower the company’s governance performance. On the other hand, investor relations officers’ beliefs that corporate sustainability is primarily driven by investors’ ethical values appear negatively related to companies’ governance performance. In sum, corporate sustainability appears positively related to internal forces (inside directors) and negatively related to external forces (general expert directors and investor activist engagement). The results of this study demonstrate the need to carry out efforts to train BoDs (specifically inside directors) and IROs to respond to corporate sustainability and to take more of a leadership role in this area.
81 citations
Trinity College, Dublin1, University of Southern Queensland2, University of Exeter3, University of Queensland4, Utrecht University5, University of Melbourne6, University of Indonesia7, Centre national de la recherche scientifique8, Paris West University Nanterre La Défense9, University of Gdańsk10, University of Lausanne11, University of Lisbon12, East China Normal University13, Université libre de Bruxelles14, University of the Witwatersrand15, University of Tennessee16, Ludwig Maximilian University of Munich17, National University of Distance Education18, Pontifical Catholic University of Chile19, The Chinese University of Hong Kong20, Aarhus University21, University of Helsinki22, Nagoya University23, University of Jena24, Universidade Federal de Sergipe25, ISCTE – University Institute of Lisbon26, University of Copenhagen27, University of Trento28, Hungarian Academy of Sciences29, Daugavpils University30, National University of Malaysia31, Kurukshetra University32, California State University33, Federal University of Paraíba34, Carleton University35
TL;DR: It is found that societal inequality enhances the perception that society is breaking down (anomie) and that a strong leader is needed to restore order (even when that leader is willing to challenge democratic values).
Abstract: Societal inequality has been found to harm the mental and physical health of its members and undermine overall social cohesion. Here, we tested the hypothesis that economic inequality is associated with a wish for a strong leader in a study involving 28 countries from five continents (Study 1, N = 6,112), a study involving an Australian community sample (Study 2, N = 515), and two experiments (Study 3a, N = 96; Study 3b, N = 296). We found correlational (Studies 1 and 2) and experimental (Studies 3a and 3b) evidence for our prediction that higher inequality enhances the wish for a strong leader. We also found that this relationship is mediated by perceptions of anomie, except in the case of objective inequality in Study 1. This suggests that societal inequality enhances the perception that society is breaking down (anomie) and that a strong leader is needed to restore order (even when that leader is willing to challenge democratic values).
76 citations
TL;DR: In this article, financial markets play a major role in contributing to the transition to a low-carbon economy, although many initiatives and developments are taking place, this is just the beginning.
Abstract: Financial markets play a major role in contributing to the transition to a low-carbon economy. Although many initiatives and developments are taking place, this is just the beginning. In this artic...
59 citations
TL;DR: The proof-of-concept experiments show that holographic imaging quality can be indeed improved by using digital meta-atoms with several bits, and the modulation of intensity distribution among focal points is experimentally realized by using the 3-bits CHM.
Abstract: In this paper, coding Huygens’ metasurface (CHM) is proposed for holographic imaging with enhanced quality. A weighted holographic algorithm is used to calculate the phase distribution at the interface and to design the CHM. Experimental demonstration performed in the microwave region validates holographic imaging with the ability to modulate energy distribution among focal points and improve image quality. By judiciously engineering both electric and magnetic dipolar resonators, the proposed digital Huygens’ meta-atom is able to provide a full transmission–phase covering the whole range of 2π together with a near-unity transmission efficiency. The proof-of-concept experiments show that holographic imaging quality can be indeed improved by using digital meta-atoms with several bits. Furthermore, the modulation of intensity distribution among focal points is experimentally realized by using the 3-bits CHM. The proposed CHM hologram shows great potential in a variety of application fields, such as programmable high-resolution imaging lenses, microscopy, data storage, information processing, and computer-generated holograms.
48 citations
TL;DR: An ultrathin reflection-type metamirror is proposed for multi-focusing with any desired focusing fashion including focal number and location, which provides a high-performance solution for low-cost and lightweight beam-shaping and beam-f focusing devices.
Abstract: An ultrathin reflection-type metamirror is proposed for multi-focusing with any desired focusing fashion including focal number and location. The metamirror is composed of reflection-type Pancharatnam–Berry (P-B) phase elements, which are able to provide full reflection phase of 2π, together with near-unity reflection efficiency by judiciously engineering the rotation angle of each latter element. A holographic algorithm is utilized to calculate the phase distribution at the interface of the metamirror to achieve the desired multi-focus spots. Experimental demonstrations performed in microwave region show good imaging quality with high reflection efficiency and imaging efficiency. The proposed metamirror provides a high-performance solution for low-cost and lightweight beam-shaping and beam-focusing devices.
42 citations
TL;DR: In this article, the authors study the case of the socially responsible investment (SRI) industry in France and present three complementary factors in the process of causing corporations to transition toward more sustainable businesses: the role of investors and, in particular, institutional investors, the importance of a clear category definition and the presence of intermediary organizations, providing ratings, scores, and other calculative devices.
Abstract: This paper studies the case of the socially responsible investment (SRI) industry in France. This case accounts for how the SRI category and practices have successfully moved from the margins of the industry in the late 1990s to become mainstream over two decades. We bring to the forefront the importance of three complementary factors in the process of causing corporations to transition toward more sustainable businesses: the role of investors and, in particular, institutional investors; the importance of the presence of a clear category definition and of intermediary organizations, providing ratings, scores, and other calculative devices; and the role of governments and regulators. With other studies, this case stresses the fundamental influence of investors in how corporations manage sustainability transitions.
41 citations
TL;DR: In this paper, a simulation-based approach for constructing metagratings in a ''unit cell by unit cell'' manner is presented, and designs for electrical and magnetic metagrates operating in the microwave and infrared domains.
Abstract: Metamaterial-inspired diffraction gratings, or $m\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}s$, have recently demonstrated superb efficiency in wavefront manipulation. Unfortunately, the absence of a systematic design procedure has held back the development of complex structures operating in different parts of the electromagnetic spectrum. The authors present a simulation-based approach for constructing metagratings in a ``unit cell by unit cell'' manner, and offer designs for electrical and magnetic metagratings operating in the microwave and infrared domains. These results will surely promote progress in metagrating applications.
TL;DR: In this article, the large amplitude free flexural vibration characteristics of fairly thick and thin functionally graded graphene platelets reinforced porous curved composite beams are investigated using finite element approach, which includes the influence of shear deformation which is represented through trigonometric function and it accounts for in-plane and rotary inertia effects.
Abstract: In this paper, the large amplitude free flexural vibration characteristics of fairly thick and thin functionally graded graphene platelets reinforced porous curved composite beams are investigated using finite element approach. The formulation includes the influence of shear deformation which is represented through trigonometric function and it accounts for in-plane and rotary inertia effects. The geometric non-linearity introducing von Karman’s assumptions is considered. The non-linear governing equations obtained based on Lagrange’s equations of motion are solved employing the direct iteration technique. The variation of non-linear frequency with amplitudes is brought out considering different parameters such as slenderness ratio of the beam, curved beam included angle, distribution pattern of porosity and graphene platelets, graphene platelet geometry and boundary conditions. The present study reveals the redistribution of vibrating mode shape at certain amplitude of vibration depending on geometric and material parameters of the curved composite beam. Also, the degree of hardening behaviour increases with the weight fraction and aspect ratio of graphene platelet. The rate of change of nonlinear behaviour depends on the level of amplitude of vibration, shallowness and slenderness ratio of the curved beam.
TL;DR: Repeated-sprint exercise resulted in greater inflammation after PSDEN, despite the decreased physical performance, and could explain the increased sleep drive at the post-lunch dip.
Abstract: To compare the effects of two types of partial sleep deprivation (PSD) at the beginning (PSDBN) and the end (PSDEN) of the night on mood, cognitive performances, biomarkers of muscle damage, haematological status and antioxidant responses before and after repeated-sprint exercise in the post-lunch dip. Fourteen male athletes performed the Running-based Anaerobic Sprint Test following: (i) baseline normal sleep night, (ii) PSDBN, or (iii) PSDEN in a randomized and counter-balanced order. During each condition, participants performed simple and choice reaction time tests, the Profile of Mood States, subjective sleepiness, and the Running-based Anaerobic Sprint Test. Plasma biomarkers of muscle damage, total blood count, and antioxidant activities were measured at rest and after the repeated sprint in the three conditions. PSDEN decreased Pmax (p=0.008; d=1.12), Pmean (p=0.002; d=1.33) and Pmin (p=0.006; d=1.15), whilst PSDBN decreased Pmean (p=0.04; d=0.68) and Pmin (p=0.028; d=0.58), in comparison with baseline. PSDEN exerted stronger effects on Pmax (p=0.013; d=0.74) and Pmean (p=0.048; d=0.54) than PSDBN. Moreover, PSDEN increased subjective sleepiness (p<0.001; d=1.93), while PSDBN impaired choice reaction time (p<0.001, d=1.89). Both PSD types decreased resting glutathione peroxidase (p<0.001; d=5.43, d=3.86), and increased aspartate amino-transferase levels (p<0.001; d=1.36, d=1.37) respectively for PSDEN and PSDBN. PSDEN decreased repeated-sprint performances more than PSDBN in the post-lunch dip. This could be explained by the lowered mood and resting antioxidant status and the increased inflammatory profile after PSDEN. Repeated-sprint exercise resulted in greater inflammation after PSDEN, despite the decreased physical performance. The drop of resting antioxidant defence and haemoglobin concentration after PSDEN could explain the increased sleep drive at the post-lunch dip.
TL;DR: This review will act as a catalyst enabling further interactions between the heritage science community, manuscript scholars, curators and conservators, and hope that biocodicology will become a highly relevant discipline in manuscript studies.
Abstract: Biocodicology, the study of the biological information stored in manuscripts, offers the possibility of interrogating manuscripts in novel ways. Exploring the biological data associated to parchment documents will add a deeper level of understanding and interpretation to these invaluable objects, revealing information about book production, livestock economies, handling, conservation and the historic use of the object. As biotechnological methods continue to improve we hope that biocodicology will become a highly relevant discipline in manuscript studies, contributing an additional perspective to the current scholarship. We hope that this review will act as a catalyst enabling further interactions between the heritage science community, manuscript scholars, curators and conservators.
TL;DR: Data analysis revealed that the relational factors studied exerted only indirect effects on whether online students completed the course, and perceived social support from teachers and peers as well as the feeling of belonging to the learning community were antecedents of the psychological processes studied.
Abstract: This study aims to understand and model the effects of relationship factors and intra-individual psychological factors on exam participation and achievement of students enrolled in an online university course The results of a survey of 506 students enrolled in university online courses showed that our initial theoretical model only partially fit the data In fact, data analysis revealed that the relational factors studied exerted only indirect effects on whether online students completed the course Perceived social support from teachers and peers, as well as the feeling of belonging to the learning community, were antecedents of the psychological processes studied As for academic self-efficacy and engagement in learning, they allowed us to directly predict taking and successfully passing exams The knowledge gained from this study helps us makes sense of the ways in which the various factors are related and the specific effect of each factor on the outputs considered
TL;DR: In this article, reflective metagratings have been used in beam steering applications with only as few as one degree of freedom (represented by a reactively loaded thin wire) per each propagating diffraction order.
Abstract: As opposed to metasurfaces, metagratings represent themselves sparse arrangements of scatterers. Established rigorous analytical models allow metagratings to overcome performance of metasurfaces in beam steering applications while handling less degrees of freedom. In this work we deal with reflective metagratings that have only as few as one degree of freedom (represented by a reactively loaded thin wire) per each propagating diffraction order. We present a detailed design procedure and fabrication of three experimental samples capable of establishing prescribed diffraction patterns. The samples are experimentally studied in an anechoic chamber dedicated to radar-cross-section bistatic measurements and results are compared with three-dimension full wave numerical simulations. We identify and analyze factors affecting operating frequency range of metagratings, suggest a strategy to increase the bandwidth.
TL;DR: It appeared that temporary self-exclusion is an interesting tool to protect online gamblers from excessive practices, but several modifications have to be made to improve its effectiveness and use.
Abstract: To prevent risks associated with online gambling, many jurisdictions propose self-exclusion strategies as a part of a responsible gambling policy. To protect online gamblers, French law provides for a 7-day temporary non-reducible and voluntary self-exclusion measure that applies only to select websites. The objective of our study was to evaluate the effectiveness of this self-exclusion measure for at-risk online gamblers. It was an experimental randomized controlled trial targeted at risk prevention. The main outcomes were the money wagered and time spent gambling assessed 15 days (short-term) and 2 months (medium-term) after the implementation of the self-exclusion measure. The effectiveness of self-exclusion was also compared according to the gambling type (pure chance games, such as lottery or scratch tickets, skill and chance bank games such as sports betting or horserace betting, and skill and chance games such as poker). Sixty participants were randomly assigned to the experimental condition (n = 30; with the implementation of a self-exclusion measure) or control condition (n = 30). The randomization was stratified according to their favorite game [pure chance games (n = 20), skill and chance bank games (n = 20), and skill and chance social games (n = 20)]. The results revealed that self-exclusion had no short-term impact—but did have a medium-term impact—on gambling habits. After 2 months, the gambling-related cognitions (“illusion of control” and “the perceived inability to stop gambling”) and the subscale “desire” of the Gambling Craving Scale (GACS) have decreased. Participants’ opinions about the impact and effectiveness of self-exclusion were discussed. To conclude, it appeared that temporary self-exclusion is an interesting tool to protect online gamblers from excessive practices, but several modifications have to be made to improve its effectiveness and use.
TL;DR: A new computational method called LOTUS is proposed to predict new driver genes, a machine-learning based approach which allows to integrate various types of data in a versatile manner, including information about gene mutations and protein-protein interactions, and can predict cancer driver genes in a pan-cancer setting as well as for specific cancer types.
Abstract: Cancer driver genes, i.e., oncogenes and tumor suppressor genes, are involved in the acquisition of important functions in tumors, providing a selective growth advantage, allowing uncontrolled proliferation and avoiding apoptosis. It is therefore important to identify these driver genes, both for the fundamental understanding of cancer and to help finding new therapeutic targets or biomarkers. Although the most frequently mutated driver genes have been identified, it is believed that many more remain to be discovered, particularly for driver genes specific to some cancer types. In this paper, we propose a new computational method called LOTUS to predict new driver genes. LOTUS is a machine-learning based approach which allows to integrate various types of data in a versatile manner, including information about gene mutations and protein-protein interactions. In addition, LOTUS can predict cancer driver genes in a pan-cancer setting as well as for specific cancer types, using a multitask learning strategy to share information across cancer types. We empirically show that LOTUS outperforms five other state-of-the-art driver gene prediction methods, both in terms of intrinsic consistency and prediction accuracy, and provide predictions of new cancer genes across many cancer types.
TL;DR: In this article, the authors focus on design management research and summarize the diversity of the relationship between these two interdisciplinary fields through a study of the international literature published between 1977 and 2017 on the subject.
Abstract: Defining the research in Design Management (DM) involves the intersection of two disciplines: management sciences and design sciences. We focus on design management research and summarize the diversity of the relationship between these two interdisciplinary fields through a study of the international literature published between 1977 and 2017 on the subject. Firstly, the hybrid territory of design management is defined through its keywords and their evolution; using various definitions of design management, a representation of the place of design within organizations then starts to emerge. Secondly, the analysis focuses on the five key themes of design management developed in the literature— the value of design, the methods and skills of design, the tools of design, its integration in other functions, and the theme of “better manager by design”—as well as the resulting models. Finally, this review of the literature highlights the emergence in the discourse of two complementary forces: design management and design leadership.
TL;DR: The organic halo effect was replicated but showed that, surprisingly, it does not arise from implicit associations, and Bayesian analyses yielded extremely strong evidence in favor of the hypothesis that the organic label leads to an underestimation of caloric value.
TL;DR: In this paper, the Fisher Information Metric and its associated Riemannian distance (namely, CES-Fisher) on the manifold of Hermitian positive definite matrices are derived.
Abstract: Scatter matrix and its normalized counterpart, referred to as shape matrix, are key parameters in multivariate statistical signal processing, as they generalize the concept of covariance matrix in the widely used Complex Elliptically Symmetric distributions. Following the framework of [1] , intrinsic Cramer–Rao bounds are derived for the problem of scatter and shape matrices estimation with samples following a Complex Elliptically Symmetric distribution. The Fisher Information Metric and its associated Riemannian distance (namely, CES-Fisher) on the manifold of Hermitian positive definite matrices are derived. Based on these results, intrinsic Cramer–Rao bounds on the considered problems are then expressed for three different distances (Euclidean, natural Riemannian, and CES-Fisher). These contributions are therefore a generalization of Theorems 4 and 5 of [1] to a wider class of distributions and metrics for both scatter and shape matrices.
TL;DR: In this paper, the authors proposed an alternative practical design of a metasurface-based converter by separating the incident plane wave and the surface wave in different half-spaces.
Abstract: Although a rigorous theoretical ground on metasurfaces has been established in the recent years on the basis of the equivalence principle, the majority of metasurfaces for converting a propagating wave into a surface wave are developed in accordance with the so-called generalized Snell's law being a simple heuristic rule for performing wave transformations. Recently, Tcvetkova et al. [Phys. Rev. B 97, 115447 (2018)] have rigorously studied this problem by means of a reflecting anisotropic metasurface, which is unfortunately difficult to realize, and no experimental results are available. In this paper, we propose an alternative practical design of a metasurface-based converter by separating the incident plane wave and the surface wave in different half-spaces. It allows one to preserve the polarization of the incident wave and substitute the anisotropic metasurface by an omega-bianisotropic one. The problem is approached from two sides: By directly solving the corresponding boundary problem and by considering the "time-reversed" scenario when a surface wave is converted into a nonuniform plane wave. Particularly, we reveal that an input surface wave plays an important role in the conversion process, influencing the conversion efficiency. To validate the theory, we develop a practical three-layer metasurface based on a conventional printed circuit board technology to mimic the omega-bianisotropic response at the microwave frequency range. The design is verified by full-wave three-dimensional numerical simulations and demonstrates high conversion efficiency. Obtained results are relevant independently of the frequency range and can be generalized to acoustics domain. It enables novel applications, from efficient excitation of waveguide modes in integrated photonic circuits to cloaking of large objects.
TL;DR: Investigation of university students' self-determination motives to act upon their nutrition interact with induced regulatory focus and regulatory-message framing to predict their behaviors or intentions to improve their eating habits revealed a fit between extrinsic motives and prevention focus.
Abstract: Regulatory focus (Higgins, 1997) and self-determination (Deci & Ryan, 2000) are two motivation theories widely applied in health-intervention research but never conjointly, despite sharing a number of theoretical similarities. In three studies (N = 578), we investigated how university students' self-determination motives to act upon their nutrition interact with induced regulatory focus and regulatory-message framing to predict their behaviors or intentions to improve their eating habits. Results revealed a fit between extrinsic motives and prevention focus: Intention increased with extrinsic motives in a prevention but not a promotion focus. The effect of intrinsic motives, however, was independent of the focus, which suggests that these motives drive intention and behavior independently of external cues. Hence, the results advocate for simultaneously taking into consideration self-determination and regulatory focus when planning a health intervention relying on motivation. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
TL;DR: In this article, the authors proposed an innovative method for collimating vortex waves at microwave frequencies, based on transformation optics, which can reduce the divergence angle of vortex waves over a wide bandwidth, and collimate vortex beams with multiple modes.
Abstract: Vortex waves have potential applications in wireless communication, because of their advantages in improving channel-transmission efficiency. However, the peculiar divergence of vortex waves seriously limits their propagation distance for communication. Thus the authors propose an innovative method for collimating vortex waves at microwave frequencies, based on transformation optics. Their all-dielectric device can reduce the divergence angle of vortex waves over a wide bandwidth, and collimate vortex beams with multiple modes.
TL;DR: In this paper, the activation of a customer stereotype affects salespersons' interpersonal orientation in the context of luxury car purchases, and the results of three complementary studies indicate that status trumps gender; gender stereotypes are activated only when status is not, indicating the expectancy-based nature of sales stereotyping.
TL;DR: In this article, Wu et al. conducted a technological analysis of a "cobble-tool" industry associated with a bone tool technology from Luobi Cave, Hainan Island, and compared it with the well-studied typical Hoabinhian site of Laang Spean in Cambodia.
Abstract: The nature of Paleolithic cultures in South China and their relationship with mainland Southeast Asia remains ill-defined. The lithic industry of South China has been characterized as a simple ‘cobble-tool’ industry, persisting from the early Pleistocene to the Holocene, while the most representative Southeast Asian industry was also marked by a pebble-tool techno-complex, the Hoabinhian, during the Late Pleistocene–Early Holocene. A possible cultural link between the two regions has been proposed by some scholars but the technological characteristics of the two industries remained elusive, as did the variability within them. In this paper we conduct technological analysis of a ‘cobble-tool’ industry associated with a bone tool technology from Luobi Cave, Hainan Island, dated to c. 11–10 ka, and compare it with the well-studied typical Hoabinhian site of Laang Spean in Cambodia. While there is a slight similarity in operational sequence (chaine operatoire), a major difference is that the Luobi Cave site can be rejected as a potential Hoabinhian site. The excavated material indicates a high degree of innovation and demonstrates a new sort of variability in the tool-kit of modern human groups during the Late Pleistocene–Early Holocene transition in South China and Southeast Asia. This study represents an initial attempt to decipher the technological cultural variability in this region. We suggest that the emergence of behavioral modernity and cultural variability should be evaluated at both regional and sub-regional scales, instead of defining them as uniform, progressive and incremental, processes. Here we present, firstly, the variability of operational sequences (chaines operatoires) within the lithic production of Luobi Cave, and then compare this assemblage with typical and well-studied Hoabinhian assemblages from Laang Spean Cave in Cambodia to make clear the regional variability or complexity of human technological behaviors. Secondly, we then discuss the role of these technological behaviors as strategies for adapting to diverse ecology and environments from the Late Pleistocene to the Holocene.
TL;DR: In this article, a finite element approach is developed for the static analysis of curved nanobeams using nonlocal elasticity beam theory based on Eringen formulation coupled with a hig...
Abstract: In the present work, a finite element approach is developed for the static analysis of curved nanobeams using nonlocal elasticity beam theory based on Eringen formulation coupled with a hig...
TL;DR: In this paper, the authors examined the impact of remittance inflows on deforestation in developing countries and investigated the role of institutional quality in enhancing remittances' effect in reducing deforestation.
TL;DR: In this paper, the authors show that the implementation of inflation targeting weakens the Fisherian relation between expected depreciation and the interest rate differential (uncovered interest parity condition) and thus is conducive to the appearance of the forward bias puzzle in emerging countries.
TL;DR: In this article, a phase-gradient metasurface (MS) lens whose elements satisfy high transmittance and desired transmission phase is proposed to achieve collimation of vortex beams generated by an orbital angular momentum (OAM) radiating source.
Abstract: In this letter, a phase-gradient metasurface (MS) lens whose elements satisfy high transmittance and desired transmission phase is proposed to achieve collimation of vortex beams generated by an orbital angular momentum (OAM) radiating source. Two different phase profiles, hyperbolic and conical, are calculated and simulated. In addition, a prototype based on the conical phase profile is fabricated and experimentally tested, which verifies that the MS lens can realize effective collimation functionality. The proposed integrated lens-antenna system is able to provide new possibilities for OAM applications in radio wireless communication, imaging, and sensing.