The use of hazard road signs to improve the perception of severe bends

Collision analysis indicates that many car accidents occur when negotiating a bend. Excessive speed and steering wheel errors are often given by way of explanation. Nevertheless, the underlying origin of these dramatic errors could be, at least in part, a poor estimation of bend curvature. The aim of this study was to investigate both the assessment of bend curvature by drivers and the impact of symbolic road signs that indicate a hazardous bend on this assessment. Thus, participants first viewed a video recording showing approaching bends of different curvature before being asked to assess the curvature of these bends. This assessment could either be a verbal (symbolic control) estimation of the bend's curvature and risk, or a sensorimotor (subsymbolic control) estimation of the bend's curvature (participants were asked to turn a steering wheel to mimic the position that would be necessary to accurately negotiate the bend). Results show that very severe bends (with a radius of less than 80 m) were actually underestimated. This was associated with an underestimation of risk corresponding to these bends and a poor sensorimotor anticipation of bend curvature. Road signs, which indicate risk significantly improve bend assessment, but this was of no use for sensorimotor anticipation. Thus, other indicators need to be envisaged in order to also improve this level of control.     

Analyzing the Secure Simple Pairing in Bluetooth v4.0

This paper analyzes the security of Bluetooth v4.0’s Secure Simple Pairing (SSP) protocol, for both the Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) and Bluetooth Low Energy (LE) operational modes. Bluetooth v4.0 is the latest version of a wireless communication standard for low-speed and low-range data transfer among devices in a human’s PAN. It allows increased network mobility among devices such as headsets, PDAs, wireless keyboards and mice. A pairing process is initiated when two devices desire to communicate, and this pairing needs to correctly authenticate devices so that a secret link key is established for secure communication. What is interesting is that device authentication relies on humans to communicate verification information between devices via a human-aided out-of-band channel. Bluetooth v4.0’s SSP protocol is designed to offer security against passive eavesdropping and man-in-the-middle (MitM) attacks. We conduct the first known detailed analysis of SSP for all its MitM-secure models. We highlight some issues related to exchange of public keys and use of the passkey in its models and discuss how to treat them properly.     

Comparisons of fish meat extract desalination by electrodialysis using different configurations of membrane stack

The desalination of fish meat extract was performed via electrodialysis based on different membrane stack configurations (i.e., conventional electrodialysis or packed-bed electrodialysis) at a constant current. The salt removal and brix change showed that the diluted fish meat extract could be effectively desalted using electrodialysis, while the mostly nutritional ingredients remained in the dilution. Compared with the conventional electrodialysis (ED), a lower membrane stack potential meant lower energy consumption and higher current efficiency for the same salt removal in the packed-bed electrodialysis (PBED). The results indicated that the PBED might be more suitable for use in the fish meat extract desalination due to the effects of ion exchange resins in enhancing ion electromigration and mitigating membrane fouling.     

Shift-invariant real-time edge-enhanced VanderLugt correlator using video-rate compatible photorefractive polymer

We demonstrated a real-time shift-invariant VanderLugt correlator (VLC). The VLC was implemented with a 37 microm thick bis-triarylamine side-chain polymer matrix photorefractive (PR) polymer composite operating at 532 nm wavelength. Correlation selectivity was enhanced by real-time edge enhancement. The advantage of the VLC is that its architecture allows overcoming the PR material response speed. A correlator of this type enables a fast shift-invariant search of a large optical image database. A high degree of shift invariance in our correlator was possible because of the material thickness. The angular bandwidth of this material was measured experimentally in a degenerate four-wave mixing setup, and it was found to be in a very good agreement with the theory.     

Synthesis of cation exchange resin-supported iron and magnesium oxides/hydroxides composite for nitrate removal in water

In this study, we reported on the concept and practical use of cation exchange resin (CER) for removing anions in water via pretreating the CER with metal salts. The cation exchange resin-supported iron and magnesium oxides/hydroxides composite (Fe-Mg/CER) was synthesized and introduced as a new and potential adsorbent for selective removal of nitrate ion in the water environment. Characteristics of Fe-Mg/CER were determined by techniques such as Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The results showed that Fe-Mg/CER material had a high nitrate adsorption capacity of 200 mg NO3-·g-1 with a fast equilibrium adsorption time of 30 min at pH 5. In addition, it had good durability of at least 10 times of regeneration, which could be applied to practical water and wastewater treatment.     

Magnetocaloric effect in La1-xSrxCoO3 undergoing a second-order phase transition

We have prepared rhombohedral La_1-xSr_xCoO_3-δ (x?=?0.2–0.5) compounds with a mass density ρ?≈?5.5?g/cm³. Their magnetocaloric (MC) effect is studied via the magnetic-entropy change (ΔS_m) and relative cooling power (RCP), which are calculated from initial magnetization data recorded at different temperatures. Results reveal that the ΔS_m magnitude is maximum (ΔS_max) around the ferromagnetic-paramagnetic phase transition and dependent on both the applied-field (H) magnitude and Sr content (x). For H =?50?kOe, |ΔS_max| can be tuned in the range of 1.6–2.7?J/kg?K, corresponding to RCP values of 89–141?J/kg. Among the studied La_1-xSr_xCoO_3-δ samples, the samples with x?=?0.3–0.5 have the largest |ΔS_max| values. If combining these samples as MC blocks in refrigeration application, the working temperature range of a cooling device could range from 204 to ~280?K, with |ΔS_max| stable at ~2.6?J/kg?K and RCP ≈?198?J/kg. We have also assessed the phase-transition type and magnetic order and found La_1-xSr_xCoO_3-δ undergoing a second-order phase transition. Magnetic order tends to change from the long-range type to the short-range one when x varies from 0.2 to 0.5. This is in good agreement with the results obtained from the analysis of critical behavior.     

Enhanced microwave absorption features of Ba3Co2Fe24O41 hexaferrite by high lanthanium doping concentration

Controlling material structure and its electromagnetic properties, including complex permittivity and permeability, could enhance the microwave absorption performance of the material in terms of reflection loss and effective absorption bandwidth. In this study, La-substituted barium hexaferrite, Ba_3−xLa_xCo₂Fe₂₄O₄₁ (x = 0, 0.1, 0.3, and 0.5) compounds were successfully prepared using the solid-state reaction method, and their corresponding microstructures, static magnetic properties, and electromagnetic features in 2–18 GHz were investigated. The doping of La content increased saturation magnetization, coercivity, and remnant magnetization. The Ba_2.7La_0.3Co₂Fe₂₄O₄₁ epoxied sample with 3.5 mm thickness possessed an excellent microwave absorption of −47.3 dB at 3.52 GHz, and its corresponding effective absorption bandwidths were 3.75 GHz (2.25–6 GHz) and 0.57 GHz (17.43–18 GHz). It is shown that doping with various La concentrations on Ba₃Co₂Fe₂₄O₄₁ can be used as an effective technique to tune the performance of microwave absorbers based on barium hexaferrite.