25%小偏置碰撞策略及测试评估研究

随着汽车事故的增加,且小重叠碰撞事故死亡率居高不下,小偏置碰撞试验逐渐成为焦点。基于IIHS公布的最新车辆碰撞试验结果,统计超过100余款不同类型的25%小偏置碰撞车辆,建立碰撞转角与碰撞区域的数学模型,将25%小偏置碰撞归结为三种不同的碰撞策略,分别是吸能策略、掠过策略和掠过与吸能策略;并进行试验验证,对三种策略的优缺点进行分析。结果表明,小偏置碰撞试验可运用合理的碰撞策略达到法规要求,对25%小偏置碰撞试验具有一定的参考价值。     

A survey on fog computing for the Internet of Things

Fog computing has emerged to support the requirements of IoT applications that could not be met by today’s solutions. Different initiatives have been presented to drive the development of fog, and much work has been done to improve certain aspects. However, an in-depth analysis of the different solutions, detailing how they can be integrated and applied to meet specific requirements, is still required. In this work, we present a unified architectural model and a new taxonomy, by comparing a large number of solutions. Finally, we draw some conclusions and guidelines for the development of IoT applications based on fog.     

基于儿童使用主体的建成环境评价尺度研究

评价尺度是建筑使用后评价的基 本问题之一，它是使用者评判建成环境好 坏、优劣的重要测度标准。为弥补目前环境 评价尺度研究方面的缺失，建立与儿童使用 主体相一致的建成环境评价尺度，对儿童常 用语义量词进行汇总和筛选，采用五级线 分刻度方法进行问卷调查研究。基于儿童的 理解，通过问卷试验分析，结果表明：双侧 5级区间评价尺度为：很（负面）；有点（负 面）；中等；有点（正面）；很（正面）；单侧 5级区间评价尺度为：不；好像有点；比较； 很；特别。     

In vivo evaluation of a mucoadhesive polymeric caplet for intravaginal anti-HIV-1 delivery and development of a molecular mechanistic model for thermochemical characterization

Context and objective: The aim of this study was to develop, characterize and evaluate a mucoadhesive caplet resulting from a polymeric blend (polymeric caplet) for intravaginal anti-HIV-1 delivery.

Materials and methods: Poly(lactic-co-glycolic) acid, ethylcellulose, poly(vinylalcohol), polyacrylic acid and modified polyamide 6, 10 polymers were blended and compressed to a caplet-shaped device, with and without two model drugs 3′-azido-3′-deoxythymidine (AZT) and polystyrene sulfonate (PSS). Thermal analysis, infrared spectroscopy and microscopic analysis were carried out on the caplets employing temperature-modulated DSC (TMDSC), Fourier transform infra-red (FTIR) spectrometer and scanning electron microscope, respectively. In vitro and in vivo drug release analyses as well as the histopathological toxicity studies were carried out on the drug-loaded caplets. Furthermore, molecular mechanics (MM) simulations were carried out on the drug-loaded caplets to corroborate the experimental findings.

Results and discussion: There was a big deviation between the T_g of the polymeric caplet from the T_g's of the constituent polymers indicating a strong interaction between constituent polymers. FTIR spectroscopy confirmed the presence of specific ionic and non-ionic interactions within the caplet. A controlled near zero-order drug release was obtained for AZT (20 d) and PSS (28 d). In vivo results, i.e. the drug concentration in plasma ranged between 0.012–0.332?mg/mL and 0.009–0.256?mg/mL for AZT and PSS over 1–28 d.

Conclusion: The obtained results, which were corroborated by MM simulations, attested that the developed system has the potential for effective delivery of anti-HIV-agents.     

Chitosan Microspheres as Carriers for pH‐Indicating Species in Corrosion Sensing

Chitosan microspheres containing bromocresol green, cresol red, and phenolphthalein for corrosion detection, through pH change, are synthesized in order to be used in protective coatings for aluminium alloys. Microspheres containing corrosion detection species are characterized morphologically (SEM) and physico‐chemically (FTIR, TGA). Release studies (UV–vis) are performed in corrosion‐promoting conditions (pH, NaCl), and detection studies by immersion in media associated with corrosion activity while microspheres' sensing activity is evaluated visually. Electrochemical characterization of AA2024 substrates in the presence of chitosan spheres is performed to understand material performance, and a color change is observed as a result of local pH increase in cathodic areas when corrosion takes place. These findings can be correlated with the results from release studies and seem a promising approach for corrosion sensing purposes, not only because pH increase is possible to detect due to corrosion, but also because chitosan is considered an environmentally friendly material.     

Time-series clustering – A decade review

Clustering is a solution for classifying enormous data when there is not any early knowledge about classes. With emerging new concepts like cloud computing and big data and their vast applications in recent years, research works have been increased on unsupervised solutions like clustering algorithms to extract knowledge from this avalanche of data. Clustering time-series data has been used in diverse scientific areas to discover patterns which empower data analysts to extract valuable information from complex and massive datasets. In case of huge datasets, using supervised classification solutions is almost impossible, while clustering can solve this problem using un-supervised approaches. In this research work, the focus is on time-series data, which is one of the popular data types in clustering problems and is broadly used from gene expression data in biology to stock market analysis in finance. This review will expose four main components of time-series clustering and is aimed to represent an updated investigation on the trend of improvements in efficiency, quality and complexity of clustering time-series approaches during the last decade and enlighten new paths for future works.     

Corrosion behavior of Cu–Sn bronze alloys in simulated archeological soil media

The corrosion behavior of synthetic Cu–Sn bronze alloys with six different Sn contents was examined through an electrochemical test and a synthetic test in a simulated corrosive medium. The mechanism of corrosion and the morphology of the corroded surfaces were characterized through field emission scanning electron microscopy equipped with energy-dispersive spectroscopy. At the corrosion potential, the corrosion behavior appears to be determined by the charge transfer step and the diffusion process. It was found that the bronze-IV (Cu–26.8Sn) specimen exhibited the best corrosion resistance, as evidenced by a low corrosion current density and a high impedance. This improvement resulted from an increase in the content of the Cu–Sn solid solution in the alloy, which was conducive to forming a relatively more protective passive film on the surface of the bronze alloy. This finding would be valuable in the anticorrosion protection of archeological artefacts after their excavation.     

Moving the goal posts: a reply to Dawson and Piercey

Berkeley [Minds Machines 10 (2000) 1] described a methodology that showed the subsymbolic nature of an artificial neural network system that had been trained on a logic problem, originally described by Bechtel and Abrahamsen [Connectionism and the mind. Blackwells, Cambridge, MA, 1991]. It was also claimed in the conclusion of this paper that the evidence was suggestive that the network might, in fact, count as a symbolic system. Dawson and Piercey [Minds Machines 11 (2001) 197] took issue with this latter claim. They described some lesioning studies that they argued showed that Berkeley’s (2000) conclusions were premature. In this paper, these lesioning studies are replicated and it is shown that the effects that Dawson and Piercey rely upon for their argument are merely an artifact of a threshold function they chose to employ. When a threshold function much closer to that deployed in the original studies is used, the significant effects disappear.     

低温送风系统末端装置诱导器的研究及性能评价

研究了在低温送风系统中诱导器(IDU)的结构特点、工作原理、送风方式,分析了诱导器送风口射流速度的特性,得出了诱导器空调系统的优缺点。