Enhancing Security and Privacy in Traffic-Monitoring Systems

Intelligent transportation systems increasingly depend on probe vehicles to monitor traffic: they can automatically report position, travel time, traffic incidents, and road surface problems to a telematics service provider. This kind of traffic-monitoring system could provide good coverage and timely information on many more roadways than is possible with a fixed infrastructure such as cameras and loop detectors. This approach also promises significant reductions in infrastructure cost because the system can exploit the sensing, computing, and communications devices already installed in many modern vehicles. This architecture separates data from identities by splitting communication from data analysis. Data suppression techniques can help prevent data mining algorithms from reconstructing private information from anonymous database samples     

Effects of thermo-mechanical processing and trace amount of carbon addition on tensile properties of Cu–2.5Fe–0.1P alloys

The effects of thermo-mechanical processing, including intermediate aging treatment and/or solution heat treatment, and a trace amount of carbon (C) addition were studied on tensile behavior of Cu–2.5Fe–0.1P alloys. In this study, Cu–2.5Fe–0.1P alloy sheets without and with a carbon content of 0.05 wt.% were cast and subsequently rolled and thermo-mechanically treated following various processing routes. The introduction of intermediate aging treatment between cold rolling improved the tensile strength of Cu–2.5Fe–0.1P alloys. Solution heat treatment prior to aging was proved to be detrimental on the tensile strength, probably due to recovery and recrystallization causing the complete loss of work hardening during previous cold rolling. The present study also suggested that two-step aging is more effective in improving the strength of Cu–2.5Fe–0.1P alloys than one-step aging. The effect of C addition on improving the tensile strength of Cu–2.5Fe–0.1P alloys was real but marginal, probably due to the limited solubility of C in Cu–2.5Fe matrix. The effects of intermediate heat treatments between cold-rolling processes on tensile properties of Cu–2.5Fe–0.1P specimens with and without C addition are discussed based on optical, scanning electron microscope (SEM) and transmission electron microscope (TEM) micrographs, and SEM fractographs.     

Neurofilament-L homopolymers are less mechanically stable than native neurofilaments

Neurofilaments are cytoskeletal components of neurones that are thought to play an important structural role in the axon. Specific functions of neurofilaments are not yet well defined; however, other intermediate filaments are known to have structural and mechanical functions in different cell types. The atomic force microscope (AFM) can be used to visualize and manipulate biological structures through direct physical contact. This allows the AFM to be used to probe the mechanical properties of these structures. In this paper we present AFM images of native neurofilaments isolated from bovine spinal cord, composed of NF-L, NF-M and NF-H, and filaments polymerized in vitro from purified NF-L. Morphologically these structures, in solution and under ambient conditions, are in agreement with previous data from electron microscopy. However, repeated scanning of NF-L homopolymers (in solution) produced significant disruptions of segments of filaments, both within and at the ends of the filaments. This disruption resulted in complete loss of portions of the filaments and in breaks in the continuity of the filaments. Repeated scanning of isolated native neurofilaments under similar conditions produced no detectable structural changes. Under extremely high applied forces the native neurofilaments were bent and distorted by the action of the AFM tip, but were never broken. These data suggest that purified NF-L is not sufficient to confer complete mechanical stability to neurofilaments.     

Spectroscopic studies of the gradient in the silane coupling agent/matrix interface in fiberglass-reinforced epoxy

Differential scanning calorimetry, Fourier transform infrared, and solid-state carbon 13 nuclear magnetic resonance were used to study the silane coupling agent/epoxy resin interface. Penetration of epoxy into the hydrolyzed silane has been shown. The addition of a solvent can further increase the penetration of epoxy into the hydrolyzed silane by decreasing the viscosity of the epoxy. Bulk models of the gradient in the silane coupling agent/epoxy interface have shown that the concentration of silane and the degree of hydrolysis of the silane can determine the rigidity or mobility of the interphase region. When the silane is hydrolyzed, the possible formation of entanglements may increase the rigidity of the system and decrease the degree of phase separation through the formation of an interpenetrating network.     

生产微合金化钢的几点考虑

在20世纪60～80年代,连续浇铸是钢铁工业的一项重要的工艺变革。这项技术无论对提高炼钢生产效率还是改善产品质量都产生了深刻的影响。然而,为保持产品竞争力和成本效益,需要一个统筹的炼钢方法。从铁水生产开始或者从冶炼开始,经过精炼到连铸,再到轧钢和后续工序,钢产品的整条生产路线应该整体可控。关于连铸,有2个实例可以说明这种发展趋势:改进中间包设计和冶金技术,优化浸入式水口和高水平的结晶器液面控制。无止境的洁净钢研究已经从连铸机本身转到钢包冶金。同样,无缺陷表面质量研究不再简单地专注于连铸技术,同时也将炼钢考虑进去。随着结构钢品种的合金设计转变,从普通的中碳锰钢到裂纹敏感的现代低碳微合金化HSLA钢,连铸机的设计和技术发展并驾齐驱。     

Improved separation of complex polycyclic aromatic hydrocarbon mixtures using novel column combinations in GC × GC/ToF-MS

Complex mixtures of polycyclic aromatic hydrocarbons (PAHs) are difficult to resolve because of the high degree of overlap in compound vapor pressures, boiling points, and mass spectral fragmentation patterns. The objective of this research was to improve the separation of complex PAH mixtures (including 97 different parent, alkyl-, nitro-, oxy-, thio-, chloro-, bromo-, and high molecular weight PAHs) using GC × GC/ToF-MS by maximizing the orthogonality of different GC column combinations and improving the separation of PAHs from the sample matrix interferences, including unresolved complex mixtures (UCM). Four different combinations of nonpolar, polar, liquid crystal, and nanostationary phase columns were tested. Each column combination was optimized and evaluated for orthogonality using a method based on conditional entropy that considers the quantitative peak distribution in the entire 2D space. Finally, an atmospheric particulate matter with diameter <2.5 μm (PM(2.5)) sample from Beijing, China, a soil sample from St. Maries Creosote Superfund Site, and a sediment sample from the Portland Harbor Superfund Site were analyzed for complex mixtures of PAHs. The highest chromatographic resolution, lowest synentropy, highest orthogonality, and lowest interference from UCM were achieved using a 10 m × 0.15 mm × 0.10 μm LC-50 liquid crystal column in the first dimension and a 1.2 m × 0.10 mm × 0.10 μm NSP-35 nanostationary phase column in the second dimension. In addition, the use of this column combination in GC × GC/ToF-MS resulted in significantly shorter analysis times (176 min) for complex PAH mixtures compared to 1D GC/MS (257 min), as well as potentially reduced sample preparation time.     

Dynamic pricing incentive for participatory sensing

User participation is one of the most important elements in participatory sensing application for providing adequate level of service quality. However, incentive mechanism and its economic model for user participation have been less addressed so far in this research domain. This paper studies the economic model of user participation incentive in participatory sensing applications. To stimulate user participation, we design and evaluate a novel reverse auction based dynamic pricing incentive mechanism where users can sell their sensing data to a service provider with users’ claimed bid prices. The proposed incentive mechanism focuses on minimizing and stabilizing the incentive cost while maintaining adequate level of participants by preventing users from dropping out of participatory sensing applications. Compared with random selection based fixed pricing incentive mechanism, the proposed mechanism not only reduces the incentive cost for retaining the same number of participants but also improves the fairness of incentive distribution and social welfare. It also helps us to achieve the geographically balanced sensing measurements and, more importantly, can remove the burden of accurate price decision for user data that is the most difficult step in designing incentive mechanism.     

Topic Modeling Based Warning Prioritization from Change Sets of Software Repository

Journal of Computer Science and Technology - Many existing warning prioritization techniques seek to reorder the static analysis warnings such that true positives are provided first. However,...     

Novel flame retardants, 1,2-bis(2,4,6-tribromophenoxy)ethane and 2,3,4,5,6-pentabromoethylbenzene, in United States' environmental samples

Two brominated flame retardants, 1,2-bis(2,4,6-tribromophenoxy)ethane (TBE) and 2,3,4,5,6-pentabromoethylbenzene (PEB), were detected and identified in ambient air samples from various sites in the United States. The identifications were confirmed by comparing the gas chromatographic retention times and mass spectra of the compounds found in the environment with those of authentic materials. Generally, the TBE concentrations in air were comparable to those of tetra- through hexabrominated diphenyl ethers (PBDEs) and often higher than those of decabromodiphenyl ether (BDE-209). The atmospheric TBE concentrations at locations in the southern United States were higher than those in the northern United States. TBE was also found in a sediment core from Lake Michigan; the concentrations of TBE increased with time, were lower than those of BDE-209, but were approximately 10 times higher than the sum of BDE-47, -99, and -100. The maximum PEB concentration in Chicago air was 550 pg/ m3, which was 10 times higherthan the concentration of total PBDEs in this sample. In general, the concentrations of PEB in air samples were low but detectable and were less than those of PBDEs. PEB was not found in the sediment core from Lake Michigan. These occurrences of relatively high concentrations of TBE and PEB in environmental samples may reflect the increasing usage of these compounds as flame retardants.     

Nanometer-scale oxide thin film transistor with potential for high-density image sensor applications

The integration of electronically active oxide components onto silicon circuits represents an innovative approach to improving the functionality of novel devices. Like most semiconductor devices, complementary-metal-oxide-semiconductor image sensors (CISs) have physical limitations when progressively scaled down to extremely small dimensions. In this paper, we propose a novel hybrid CIS architecture that is based on the combination of nanometer-scale amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) and a conventional Si photo diode (PD). With this approach, we aim to overcome the loss of quantum efficiency and image quality due to the continuous miniaturization of PDs. Specifically, the a-IGZO TFT with 180 nm gate length is probed to exhibit remarkable performance including low 1/f noise and high output gain, despite fabrication temperatures as low as 200 °C. In particular, excellent device performance is achieved using a double-layer gate dielectric (Al?O?/SiO?) combined with a trapezoidal active region formed by a tailored etching process. A self-aligned top gate structure is adopted to ensure low parasitic capacitance. Lastly, three-dimensional (3D) process simulation tools are employed to optimize the four-pixel CIS structure. The results demonstrate how our stacked hybrid device could be the starting point for new device strategies in image sensor architectures. Furthermore, we expect the proposed approach to be applicable to a wide range of micro- and nanoelectronic devices and systems.