TS Tech (Japan)

In recent years, the spread of wearable medical sensors has made it possible to easily measure biological signals such as pulse rate and body acceleration (BA), and from these biological signals, it is possible to evaluate the degree of biological stress and autonomic nervous activity in daily life. Accumulated fatigue due to all-day work and lack of sleep is thought to be a contributing factor to distracted driving, and technology to estimate fatigue from biological signals during driving is desired. In this study, we investigated fatigue evaluation during a driving simulator (DS) using biological information on seven older subjects. A DS experiment was performed in the morning and afternoon, and no significant differences were observed in the change over time of heart rate variability and skin temperature. On the other hand, in the afternoon DS, changes in arousal and body movements were observed based on BA calculated from the three-axis acceleration sensor and fingertip reaction time in a psychomotor vigilance test. It is suggested that by combining biological information, it may be possible to evaluate the degree of fatigue from the presence or absence of arousal and changes in body movements while driving.

サトイモは干ばつに弱い作物であるが，灌水のタイミングやその量についての指針がない．そこで， 収益性の観点から適正な土壌水分とその制御法について検討した．2015年に雨よけ条件下で土壌水分を体積含水率で15％，25％および35％に設定した3試験区，2017年には露地条件下で慣行区（7日おき灌水），土壌水分25％区および無灌水区の3試験区を設けた．商品収量（商品として取り扱われる孫芋とひ孫芋の収量の合計）は，土壌水分35％区および慣行区（土壌水分30％程度）で多かったが，販売単価の高い3L～Sサイズ収量は土壌水分25％区が他の2処理区と同等，あるいはやや多かった．一方，下物収量は土壌水分25％区で少なかった．以上より，収益性の観点からみると土壌水分を25％前後に制御することが単位面積当たりの収益性が優れていた．

Exhaust noise is a major contributor to the radiated noise level of a vehicle, especially at idle. The radiated noise level has to meet a certain criteria based on regulation and consumer demand. In many cases, the problem appears after the vehicle is manufactured and the tailpipe noise measurement is performed indicating a high noise level that needs to be reduced. This paper describes one of those cases where the radiated noise level of a certain passenger car at idle was required to be reduced by 6 dB(A). The exhaust system consists of one main muffler and one auxiliary muffler. A 1D two-port model of the exhaust system including the two mufflers was built using commercial software. This model was validated against the measurement of the two-port matrix of both mufflers. The model was then used together with tailpipe noise measurements to estimate the characteristics of the source strength and impedance. Using a 1D model of the complete system, it was possible to propose several modifications for the vehicle manufacturer to choose from. A systematic optimization approach is presented in this paper describing several suggestions to reduce the radiated tailpipe noise.

The combined effects of 1-menthol and ethanol as a skin permeation enhancer were evaluated with two equations describing the permeability coefficient through full-thickness skin (PFT) and the full-thickness skin/vehicle concentration ratio (CFT/CV) of drugs as a function of their octanol/vehicle partition coefficient (KOV). A two-layer model was applied for skin, which consists of a stratum corneum (SC) with lipid and porous pathways and a viable epidermis and dermis (ED). The two equations contain one variable (KOV) and nine coefficients, six of which (three diffusion coefficients, the porosity of the SC, and two terms of the linear free energy relationship) were considered different, dependent on the drug vehicle. In vitro permeation of four drugs (morphine hydrochloride, atenolol, nifedipine, and vinpocetine) was determined using excised hairless rat skin and four aqueous vehicles (water, 5% 1-menthol, 40% ethanol, and 5% 1-menthol-40% ethanol) to measure each PFT. Drug concentrations in full-thickness skin were also measured to obtain CFT/CV. A nonlinear least-squares method was employed to determine six coefficients using the two equations and experimentally obtained PFT and CFT/CV. The addition of 1-menthol to water and 40% ethanol increased the diffusion coefficient of drugs in lipid and pore pathways of SC, whereas the addition of ethanol to water and 5% 1-menthol increased the drug solubility in the vehicle, decreased the skin polarity, and increased the contribution of the pore pathway to whole-skin permeation.