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This paper reports a comprehensive study on the mechanical performance of large size superelastic shape memory alloy (SMA) bars, with the main focus given to their potential applications for seismic-resistant connections. A series of practical issues, including heat treatment, mechanical property assessment, and connection design/evaluation, were discussed aiming to benefit both material and civil engineering communities. The study commenced with a detailed discussion on the heat treatment strategy for SMA bars and the resulting mechanical properties including strength/stiffness, self-centring ability, energy dissipation, and fractural resistance. It was observed that the mechanical performance of the bars were quite sensitive to both annealing temperature and duration, and size effect was also evident, resulting in different appropriate heat treatment procedures for the bars with varying diameters. The optimally heattreated SMA bars were machined to the bolt form and were then used for two types of practical self-centring connections, namely, connection with all SMA bars and that with combined angles and SMA bars. Through conducting full-scale tests, both connections were shown to have stable and controllable hysteretic responses till 5% loading drift. Up to 3% drift, the self-centring performance was satisfactory for both connection types, but beyond that the presence of the angles could lead to accumulated residual rotation. Importantly, for both connections, the deformation was accommodated by the SMA bolts or angles, whereas no plastic deformation was observed at any other structural members. This confirmed the feasibility of using such connections for highly resilient structures where minimal repair work is required after earthquakes.

The present study applies the WRF model involving the single-layer urban canopy model (hereafter, WRF_UCM) to urban climate simulation of the Tokyo metropolitan area for August (2004)(2005)(2006)(2007) and compare results to (a) observations, and (b) the WRF model involving the slab urban model (hereafter, WRF_SLAB). In this urban area, WRF_UCM accurately captures the observed monthly mean daytime and nocturnal UHI, whereas WRF_SLAB does not show a nocturnal UHI. Moreover, the observed diurnal variations of the surface air temperature for central Tokyo and Kumagaya, a nearby inland city, are reproduced well by WRF_UCM. However, WRF_SLAB exhibits both a 1-hr phase shift and a 6.2 C excess oscillation magnitude over observations. In addition, WRF_UCM accurately reproduces the frequency distribution of surface air temperatures, showing a maximum at 27 C, whereas WRF_SLAB produce a bimodal distribution, with double peaks at 23 and 33 C. Finally, WRF_UCM does a much better job than WRF_SLAB at modeling the relative humidity.

Web service is one of the key communications software services for the Internet. Web phishing is one of many security threats to web services on the Internet. Web phishing aims to steal private information, such as usernames, passwords, and credit card details, by way of impersonating a legitimate entity. It will lead to information disclosure and property damage. This paper mainly focuses on applying a deep learning framework to detect phishing websites. This paper first designs two types of features for web phishing: original features and interaction features. A detection model based on Deep Belief Networks (DBN) is then presented. The test using real IP flows from ISP (Internet Service Provider) shows that the detecting model based on DBN can achieve an approximately 90% true positive rate and 0.6% false positive rate.

Summary This paper presents a comprehensive study on self‐centering dampers equipped with friction springs. The basic mechanical behavior of individual friction springs is first understood via analytical descriptions that are verified by a preliminary experimental study. The working principle, fabrication process, and mechanical performance of the proposed dampers are subsequently described, where the design details related to seismic applications are highlighted. This is followed by physical tests on three damper specimens, where the influence of the treatment of the taper surfaces of the friction springs on the overall damper behavior is examined, and the reliability of the dampers under repeated rounds of cyclic loading is evaluated. The damper specimens show reliable flag‐shaped load‐deformation hysteretic curves with excellent self‐centering capability. Satisfactory energy dissipation with an equivalent viscous damping (EVD) of up to 20% is shown, and the EVD is stabilized throughout the entire loading process. The dampers are capable of withstanding multiple rounds of cyclic loading with stable hysteretic behavior, indicating that they are fully reusable after multiple strong earthquakes. A larger friction coefficient on the taper surfaces leads to increased yield load and energy dissipation. Following the experimental study, some practical design recommendations are provided. Based on the available analytical model, an additional parametric study is performed to highlight the influences of precompression and friction condition of the friction springs on the damper behavior. Finally, the seismic performance of a building which adopts the friction spring dampers is evaluated via numerical simulation.

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