40 research outputs found

    Seismic Response Analysis of a Thick Overburden Consisting of Loose and Soft Soil

    Get PDF
    It is known that not only local soil conditions but also seismic wave, used in analysis, together with its input conditions had a major effect on the intensity and characteristics of ground motion. In this paper the ground motions to different input depths of base motion under the near epicenter or far epicenter conditions, using EL CENTRO record after adjusting as base motion input, for two representative sites in Shanghai were reviewed and the results of analytical studies were presented to explore the site dependent design spectra suited to local conditions

    Are Managers 'Under-the-Weather' During Earnings Conference Calls?

    Get PDF
    Earnings conference calls represent an important communication channel between managers and investors. We examine the impact of weather-induced mood on manager behavior during these calls. Using a large sample of earnings conference calls from 2006 to 2017, we find managers speak more negatively and with less (more) quantitative information (uncertainty) when local weather conditions are bad. We further identify that this negative relation is less pronounced for CFOs than CEOs. Financial expertise mitigates negative behavior bias induced by weather and we confirm with subgroups of CEOs with previous financial experience. We document a significantly negatively market reaction to weather-induced behavior that cannot be explained by existing textual analysis methods. Our results remain significant after adding controls for investor mood, separating firms into those from big and small states, mediation tests, firm fixed effects, and propensity score matching. Taken together, our findings suggest that exogenous effects of bad weather significantly impact manager behavior that the market views negatively

    In-Place FPGA Retiming for Mitigation of Variational Single-Event Transient Faults

    Full text link

    Two distinct superconducting states controlled by orientation of local wrinkles in LiFeAs

    Full text link
    We observe two types of superconducting states controlled by orientations of local wrinkles on the surface of LiFeAs. Using scanning tunneling microscopy/spectroscopy, we find type-I wrinkles enlarge the superconducting gaps and enhance the transition temperature, whereas type-II wrinkles significantly suppress the superconducting gaps. The vortices on wrinkles show a C2 symmetry, indicating the strain effects on the wrinkles. A discontinuous switch of superconductivity occurs at the border between two different wrinkles. Our results demonstrate that the local strain effect could affect superconducting order parameter of LiFeAs with a possible Lifshitz transition, by alternating crystal structure in different directions.Comment: 21 pages, 9 figure

    Multivisual Animation Character 3D Model Design Method Based on VR Technology

    No full text
    For VR systems, one of its core parts is to present people with a real and immersive 3D simulation environment. This paper uses real-time computer graphics technology, three-dimensional modeling technology, and binocular stereo vision technology to study the multivisual animation character objects in virtual reality technology; designs a binocular stereo vision animation system; designs and produces a three-dimensional model; and develops a virtual multivisual animation scene application. The main research content and work performed in the text include the research of the basic graphics rendering pipeline process and the analysis and research of each stage of the rendering pipeline. It mainly analyzes the 3D graphics algorithm used in the three-dimensional geometric transformation of computer graphics and studies the basic texture technology, basic lighting model, and other image output processes used in the fragment processing stage. Combined with the development needs of the subject, the principles of 3D animation rendering production software and 3D graphics modeling are studied, and the solid 3D model displayed in the virtual reality scene is designed and produced. This article also reflects the application of virtual reality in multivisual animation character design from the side, so it has realistic value and application prospects

    Influencing factors, mechanism and prevention of construction workers’ unsafe behaviors: a systematic literature review

    Full text link
    Unsafe behaviors of construction workers are one of the main causes of accidents at construction sites. The research on unsafe behaviors of workers helps to reduce the incidence of accidents and has attracted much attention. However, a systematic literature review in this field is still lacking, which hinders stakeholders’ comprehensive understanding of the unsafe behaviors of construction workers. Therefore, the aim of this study is to address this research gap based on retrieved literature from the Web of Science. First, the study conducted a descriptive analysis of the year, quantity, publishing organization, and keywords of the literature. In addition, three research topics were identified and discussed, including the influencing factors of construction workers’ unsafe behaviors, the formation mechanism of unsafe behaviors, and the pre-control methods of unsafe behaviors. Moreover, a research framework was proposed and future research directions were also suggested. The research findings promote stakeholders’ understanding of the influencing factors, formation mechanism, and pre-control methods of construction workers’ unsafe behaviors, and lead to future research directions in the studied field

    Determination of apparent bulk velocity of auroral images

    Get PDF
    In this paper we use a correlation analysis technique of random pattern to calculation of shift velocity of auroral image. The velocity thus obtained is a kind of apparent "average" velocity of whole image, instead of the velocity of some certain points or parts in the auroral pattern. The technique is used to an example of aurora australis recorded at Zhongshang Station of Antarctica in 1997. The typical velocity of the auroral pattern for the studied cases is about 3 km/

    Ultrafine MnO2 Nanowire Arrays Grown on Carbon Fibers for High-Performance Supercapacitors

    Get PDF
    Abstract Large-area ultrafine MnO2 nanowire arrays (NWA) directly grew on a carbon fiber (CF, used as a substrate) by a simple electrochemical method, forming three-dimensional (3D) hierarchical heterostructures of a CF@MnO2 NWA composite. As an electrode for supercapacitors, the CF@MnO2 NWA composite exhibits excellent electrochemical performances including high specific capacitance (321.3 F g−1 at 1000 mA g−1) and good rate capability. Further, the overall capacitance retention is ~99.7 % capacitance after 3000 cycles. These outstanding electrochemical performances attribute to a large number of transport channels for the penetration of electrolyte and the transportation of ions and electrons of electrodes. The as-prepared CF@MnO2 NWA composite may be a promising electrode material for high-performance supercapacitors

    Fall perception for elderly care: A fall detection algorithm in Smart Wristlet mHealth system

    No full text
    Mobile Health (mHealth) is expected to play a special role in today and the future healthcare delivery. Based on this trend, we design a Smart Wristlet mHealth system with mobile interface. The designed Smart Wristlet is dedicated to offer real-time alert for elderly fall, which is the most important when population ageing is becoming. In the Smart Wristlet mHealth system, fall detection is the 'bottleneck' of the system operation. To remove this bottleneck away, we propose a fall perception solution for elderly care. In this proposal, we abstract and construct primitive-based features from raw data collected by the Smart Wristlet mHealth system, in which the most valuable features can be selected by using a TF-IDF (Term Frequency-Inverse Document Frequency) metric. In reality, these selected features are the most effective to perform fall detection. Our system tests and clinical trials demonstrate that this proposal is eligible to turn the Smart Wristlet mHealth system into a real solution for elderly care. Results show that the recognition precision and recall can reach 93% and 88%, respectively. Compared with existing solutions, the gain from our proposal is an efficient prevention method for elderly fall, and can save more than 800 million dollars per year at today's socio-economic level. ? 2014 IEEE.EI

    A Dynamic Coupled Elastoplastic Damage Model for Rock-like Materials Considering Tension-Compression Damage and Pressure-Dependent Behavior

    No full text
    A dynamic coupled elastoplastic damage model for rock-like materials is proposed. The model takes unified strength theory as the strength criterion. To characterize the different damage between compression and tension, two damage variables both in compression and in tension are introduced into the model. The former is represented by the generalized shear plastic strain and volumetric plastic strain and the latter is expressed with the generalized shear plastic strain. Furthermore, the model takes the strain rate effect into account to reflect the strength enhancement under dynamic loading. Because of the difference in plastic hardening between compression and tension, a modified hardening function is adopted. At the same time, the volume strain from HJC model is modified to be consistent with one of continuum mechanics. The developed model is numerically implemented into LS-DYNA with a semi-implicit algorithm through a user-defined material interface (UMAT). The reliability and accuracy of the developed model are verified by the simulation of four basic experiments with different loading conditions. The proposed model was found to be applicable to different mechanical behaviors of rock-like materials under static and dynamic loading conditions
    corecore