Toward an RSU-unavailable lightweight certificateless key agreement scheme for VANETs

Vehicle ad-hoc networks have developed rapidly these years, whose security and privacy issues are always concerned widely. In spite of a remarkable research on their security solutions, but in which there still lacks considerations on how to secure vehicle-to-vehicle communications, particularly when infrastructure is unavailable. In this paper, we propose a lightweight certificateless and one-round key agreement scheme without pairing, and further prove the security of the proposed scheme in the random oracle model. The proposed scheme is expected to not only resist known attacks with less computation cost, but also as an efficient way to relieve the workload of vehicle-to-vehicle authentication, especially in no available infrastructure circumstance. A comprehensive evaluation, including security analysis, efficiency analysis and simulation evaluation, is presented to confirm the security and feasibility of the proposed scheme

Landslides Caused by Climate Change and Groundwater Movement in Permafrost Mountain

Climate change induced warming results in permafrost degradation. Melting permafrost subsequently leads to an increased incidence of landslides. The study area was within the northwest section of the Lesser Khingan Range in northern China along the Bei\u27an-Heihe Highway. We analyzed the impact of climate change on landslide movement in the permafrost zone via a combination of geological survey and meteorological data. The average annual temperature of the study area has increased by 3.2°C in last 60 years, and permafrost degradation is severe. Loose soil on the hillside surface provides appropriate conditions for the infiltration of atmospheric precipitation and snowmelt, and seepage from thawing permafrost. As it infiltrates downwards, water is blocked by the underlying permafrost or dense soil, and infiltrates along this barrier layer toward lower positions, forming a potential sliding zone. The combination of high density resistivity (HDR) methods based on soil resistivity values, ground-penetrating radar (GPR) methods based on characteristics of radar wave reflection, respectively, and geological drilling can be utilized to determine the regional stratigraphic distribution. This will allow the exact location of the landslide sliding surface to be precisely determined. Field test results indicate that radar reflectivity characteristics and the resistivity values of the soil in the landslide mass is significantly different from surrounding soil. There are sudden decreases in the apparent resistivity values at the sliding surface location. In addition, the radar exhibits strong reflection at the sliding surface position, with a sudden increase in the amplitude of the radar wave. Drilling results indicate that the soil has high water content at the location of the sliding surface of the landslide mass in the study area, which is entirely consistent with the GPR and HDR results. Thus, abnormal radar wave reflection and abrupt changes in apparent resistivity values can be used in practice to identify the location of landslide sliding surfaces in this region. We produce a detailed analysis of a representative landslide within the study area. Displacement monitoring locations were positioned at the trailing edge of the landslide mass and on the landslide mass surface. We then used this data to determine the relationships of landslide movement with both ground temperature and the trailing edge pore water pressure. The results suggest seasonal variation in the landslide movement process and characteristics of an annual cyclical trend. Landslide movement can be described by intermittence and low angles. The slip rate and the timing of slide occurrence exhibit relationships with the trailing edge pore water pressure of the landslide mass. The seepage of thaw water into the landslide mass will impact the trailing edge pore water pressure of the landslide mass. This phenomenon is identified as the primary cause of landslide movement

Ag nanoparticles/PPV composite nanofibers with high and sensitive opto-electronic response

The novel Ag nanoparticles/poly(p-phenylene vinylene) [PPV] composite nanofibers were prepared by electrospinning. The transmission electron microscope image shows that the average diameter of composite fibers is about 500 nm and Ag nanoparticles are uniformly dispersed in the PPV matrix with an average diameter of about 25 nm. The Fourier transform infrared spectra suggest that there could be a coordination effect to a certain extent between the Ag atom and the π system of PPV, which is significantly favorable for the dissociation of photoexcitons and the charge transfer at the interface between the Ag nanoparticle and the PPV. The Au top electrode device of the single Ag/PPV composite nanofiber exhibits high and sensitive opto-electronic responses. Under light illumination of 5.76 mW/cm2 and voltage of 20 V, the photocurrent is over three times larger than the dark current under same voltage, which indicates that this kind of composite fiber is an excellent opto-electronic nanomaterial

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

The complete chloroplast genome of Callicarpa integerrima var. chinensis (Lamiaceae) from Guilin, China, a potential medicinal plant

Callicarpa integerrima var. chinensis is one of the traditional medical herbs which has the potential for multiple diseases’ treatment. In this study, the complete chloroplast genome sequence of C. integerrima var. chinensis was sequenced and assembled. A typical quadripartite structure was observed in the chloroplast genome of C. integerrima var. chinensis which was 154179 bp in length, including a pair of inverted repeat (IR) regions (each 51396 bp) separated by a large single-copy region (LSC) of 84927 bp and a small single-copy region (SSC) of 17856 bp, and the overall GC contents of the chloroplast genome was 38.08%. Additionally, we annotated 132 genes, including 86 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Phylogenetic analysis was adopted which confirmed the position of C. integerrima var. chinensis was close to the congeneric C. formosana and C. siongsaiensis

High-performance binary blazed grating coupler used in silicon-based hybrid photodetector integration

An efficient and high-performance binary blazed grating coupler was designed based on silicon-on-insulator (SOI) used for silicon-based hybrid photodetector integration in an arrayed waveguide grating demodulation integrated microsystem. A relatively high coupling efficiency was obtained to optimize mode matching by the finite-difference time-domain method by choosing appropriate grating parameters, including period, etching depth, and fill factor. Coupling efficiency output at 1550 nm for the TE mode reached 68%. This value was \u3e60% in the wavelength range of 1450 to 1600 nm, specifically 71.4% around 1478 nm. An InP/InGaAs photodetector and SOI wafer were integrated by using benzocyclobutene (BCB) bonding. When the thickness of the BCB bonding layer was 440 nm, power absorption efficiency at 1550 nm for the TE mode reached 78.5%, whereas efficiency reached similar to 81.8% around 1475 nm

Throughout positive solutions of second-order nonlinear differential equations

In this paper, we consider the second-order nonlinear and the nonlinear neutral functional differential equations $$displaylines{ (a(t)x'(t))'+f(t,x(g(t)))=0,quad tgeq t_0cr (a(t)(x(t)-p(t)x(t-au))')'+f(t,x(g(t)))=0,quad tgeq t_0,. }$$ Using the Banach contraction mapping principle, we obtain the existence of throughout positive solutions for the above equations

Measurement of sustainable development index in China’s manufacturing industry based on Er-xiang Dual theory

In the era of high-quality development, the sustainable development of manufacturing industry has shown characteristics of the Er-xiang Dual. In this paper, we mainly adopt the Er-xiang Dual theory to construct the theoretical framework on the sustainable development of the manufacturing industry, and deduced the indexes of the sustainable development in the manufacturing sector, including the state index, process index, coordination index and comprehensive index. Subsequently, we have used the cross-sectional data of average for 2016–2018 to carry out an empirical analysis in the manufacturing sector in 30 provinces of China, and divided these 30 provinces into four echelons according to the comprehensive index. Finally, we have put forward four kinds of development strategies, namely, “creating demonstrations”, “making up for the points of weakness”, “enhancing the industrial advantages” and “cultivating the development features”. This study has enriched the theoretical framework of the sustainable development in the manufacturing sector in the era of high-quality development from the perspective of system theory, which will provide vital references to accurately assess the level of the sustainable development in the manufacturing industry in various regions of China and to formulate classified development strategies