Computer vision and driver distraction: Developing a behaviour-flagging protocol for naturalistic driving data

Naturalistic driving studies (NDS) allow researchers to discreetly observe everyday, real-world driving to better understand the risk factors that contribute to hazardous situations. In particular, NDS designs provide high ecological validity in the study of driver distraction. With increasing dataset sizes, current best practice of manually reviewing videos to classify the occurrence of driving behaviours, including those that are indicative of distraction, is becoming increasingly impractical. Current statistical solutions underutilise available data and create further epistemic problems. Similarly, technical solutions such as eye-tracking often require dedicated hardware that is not readily accessible or feasible to use. A computer vision solution based on open-source software was developed and tested to improve the accuracy and speed of processing NDS video data for the purpose of quantifying the occurrence of driver distraction. Using classifier cascades, manually-reviewed video data from a previously published NDS was reanalysed and used as a benchmark of current best practice for performance comparison. Two software coding systems were developed – one based on hierarchical clustering (HC), and one based on gender differences (MF). Compared to manual video coding, HC achieved 86 percent concordance, 55 percent reduction in processing time, and classified an additional 69 percent of target behaviour not previously identified through manual review. MF achieved 67 percent concordance, a 75 percent reduction in processing time, and classified an additional 35 percent of target behaviour not identified through manual review. The findings highlight the improvements in processing speed and correctly classifying target behaviours achievable through the use of custom developed computer vision solutions. Suggestions for improved system performance and wider implementation are discussed.     

Influence of polymer polarity on photochromic behavior of naphthodipyran doped in different polymeric matrixes

Photochromic polymer films were prepared by doping the naphthodipyran into different polymers such as Polyvinylpyrrolidone (PVP), styrene‐butadiene‐styrene (SBS) triblock copolymer, and polymethyl methacrylate (PMMA) at different concentrations. The kinetics of the photochromism/decoloration in the thin films was quantified by fitting biexponential equations to their photochromic decay curves after UV irradiation. The results show that the fastest decoloration process was in SBS, and the slowest one was in PVP. The DSC results indicate that T_g of polymeric matrix has no obvious effect on the decoloration rate of naphthodipyran. The decreasing order of the decoloration constant of naphthodipyran was consistent with increasing polarity of polymer matrixes as PVP > PMMA > SBS. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Load transfer in fractured carbon nanotubes under tension

The previous experimental evidence revealed that tensile fracture of a carbon nanotube (CNT) is triggered from the outermost layer of the graphene sheets, and then the crack grows toward the inner sheets. This work studies load transfer among the graphene sheets when a crack grows into the inner sheets. Both shear-lag modeling and finite element analysis (FEA) have been employed for analyzing the stress distribution in the graphene sheets. Numerical computations are given to the cases in which the wall numbers are two, five, and ten, respectively. The effects of the number of layers and the aspect ratio on the load transfer efficiency have been examined. The energy release and the effective Young’s modulus of a fractured CNT with respect to the number of broken layers are computed. The stress concentration at the crack tip grows with the radial crack propagation. The increase in the interlayer shear stress leads to crack deflection that forms the sword-and-sheath type of tensile fracture.     

Illicaborins A–C,three prenylated C6–C3 compounds from the fruits of Illicium arborescens

Three new prenylated C₆–C₃ compounds, illicaborins A–C (1–3), were isolated and characterised from the fruits of Illicium arborescens Hayata. Their structures were determined by extensive spectroscopic analyses (UV, CD, IR, ¹H NMR, ¹³C NMR, ¹H–¹H COSY, HMQC, HMBC, and NOESY) including molecular modelling. Compound 1 possesses a new carbon skeleton having a prenylated C₆–C₃ skeleton with an additional CH₂OH group at the C-2 position. The cytotoxic activities of compounds 1–3 were tested and evaluated against Hep-2, Daoy, MCF-7 and WiDr tumour cell lines.     

Real‐time diagnosing polymer processing in injection molding using ultrasound

Ultrasonic diagnosing technique with a new high‐temperature ultrasonic transducer is developed to real‐time diagnose polymer processing and its morphology changes in injection molding processing. Compared with the previous researches, the new technique can provide more and accurate information. In this study, ultrasound diagnosis shows that longitudinal wave can real‐time characterize the data of the injection process and polymer morphology changes, including melt flow arrival time, the part ejection time, filling and packing stages, polymer solidification process, and the morphology changes during polymer crystallization. Shear waves can real‐time diagnose Young's and shear storage modulus, anisotropy property of polymer in injection molding. During our research, real‐time ultrasonic diagnosis shows that the storage modulus along the vertical direction is larger than that of the parallel to the melt flow direction under our setup injection conditions. Scanning electron microscopy and dynamic mechanical analysis measurements present that it is because the crystalline lamellas of HDPE are parallel arrangement and grow in a vertical to melt flow direction owing to injection shear force under a certain injection conditions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Bandwidth-Constrained Routing Problem in Wireless Ad Hoc Networks

The bandwidth-constrained routing problem (BCRP) asks for a route that has sufficient bandwidth for data transmission. When BCRP is defined for wired networks, it can be solved in polynomial time. On the other hand, when it is defined for wireless ad hoc networks, it is NP-complete if the underlying MAC protocol is TDMA-based or CDMA-over-TDMA-based. In this paper, we show that BCRP is still NP-complete, even if CSMA-based or contention-based CDMA MAC prot.ocols are used. Besides, we show that BCRP is polynomial-time solvable if the channel model is collision-free and the scheduling policy is FIFO. In wireless ad hoc networks, no MAC protocol was designed before, which would lead to a polynomial-time solution to BCRP. The results of this paper suggest a design for MAC protocols that can support QoS routing well.     

In vitro antioxidant activity of liquor and semi-purified fractions from fermented squid pen biowaste by Serratia ureilytica TKU013

Antioxidative activities were found in the culture supernatant of Serratia ureilytica TKU013 with squid pen as the sole carbon/nitrogen source. The 4th day supernatant showed the strongest antioxidant activities and the highest total phenolic content. The supernatant was further purified by liquid–liquid partition, and it was found that the ethyl acetate-soluble (EA) extract exhibited the strongest antioxidant activity in a DPPH radical-scavenging assay and this was compared with the positive control, α-tocopherol. This extract was further divided into eight fractions, designated as F1–F8, by silica gel liquid chromatography. In most cases, F4 and F8 were found to possess the strongest antioxidative activities. Significant associations between the antioxidant potency and the total phenolic content, as well as between the antioxidant potency and free amino groups, were found for the supernatant, extract, and fractions. With this method, squid pen waste can be utilized and has potential in the production of functional foods.     

Extending the TAM model to explore the factors that affect Intention to Use an Online Learning Community

An online learning community enables learners to access up-to-date information via the Internet anytime–anywhere because of the ubiquity of the World Wide Web (WWW). Students can also interact with one another during the learning process. Hence, researchers want to determine whether such interaction produces learning synergy in an online learning community. In this paper, we take the Technology Acceptance Model as a foundation and extend the external variables as well as the Perceived Variables as our model and propose a number of hypotheses. A total of 436 Taiwanese senior high school students participated in this research, and the online learning community focused on learning English. The research results show that all the hypotheses are supported, which indicates that the extended variables can effectively predict whether users will adopt an online learning community. Finally, we discuss the implications of our findings for the future development of online English learning communities.