National Institute of Technology, Nagano College

The human sense of self is plastic and can be modulated by multisensory and sensorimotor coupling in immersive virtual reality. In particular, synchronous visuo-tactile stimulation and visuo-motor coupling via first-person control are widely used to induce embodiment. However, when these two streams promote different candidate self-locations, their relative contributions to the perceived self-location remain unclear. In this study, we examined perceived self-location using a robot-mediated self-touch paradigm that creates a cue conflict: synchronous visuo-tactile stimulation in this paradigm tends to bias self-location toward the participant’s physical body, whereas visuo-motor coupling via first-person control tends to bias self-location toward a remote robot viewpoint. We compared this conflict condition with control conditions in which either the visuo-tactile or visuo-motor stimulation was attenuated. Perceived self-location was assessed using questionnaire ratings and a behavioral estimate, namely, the Self-Location EstimatEd Pointing (SLEEP), which estimates participants’ perceived self-location using a finger-pointing task in a 360 degree image. Overall, the results are consistent with a stronger contribution of synchronous visuo-tactile stimulation than visuo-motor coupling to perceived self-location in this whole-body embodiment setting.

Miniature screws are a standard for screws with a nominal diameter of 0.3 mm to 1.4 mm, and are used in watches, optical equipment, electrical equipment, measuring equipment, etc. Machining female threads with a fluteless tap is a plastic working process that does not produce chips and has a long tool life, but it is often used for small diameter machining and is prone to tool breakage. The authors attempted to reduce the machining torque by using ultrasonic vibration for machining internal threads of miniature screws. Two types of ultrasonic vibrations, 28kHz and 40kHz, were applied to investigate the relationship between vibration frequency and machining torque. The tap used this time is a fluteless tap with a nominal diameter of 0.5 mm, which is the smallest diameter tap available on the market. Experimental conditions were investigated with and without tapping paste. As a result, the effect of ultrasonic vibration was higher when tapping paste was used.

高いエネルギー分解能をもつ無機半導体放射線検出器は，素粒子・原子核実験などの分野で使用されているが，高純度な単結晶構造を必要とし柔軟性がなく高価で大型化が難しい。本研究は，結晶構造をもたない有機材料に着目した新しい放射線検出器の開発を行った。放射線感度を高めるために，n型半導体の性質をもつ二酸化チタンを混合して有機無機ハイブリッドセンサを試作した。本論文では，二酸化チタンの含有量や粒子径の違いによるセンサ性能への影響や特徴について述べる。

This paper describes the contents of a global engineer training program at National Institute of Technology (KOSEN), Nagano College. The contents include the details of classes, overseas training, campus globalization, and e-learning system. Each program is mindful of international exchanges during the COVID-19 pandemic and this paper shows their current outcomes.

Variable magnetic flux motors have been proposed to achieve high-efficiency operation over a wide drive range ranging from high torque to high-speed. This paper clarifies the high efficiency area expansion effect of a variable flux motor with a magnetic composite material inserted in the rotor. To achieve the effect of enlarging the maximum efficiency range, this motor uses magnetic composite materials with much lower saturation magnetic flux density and iron loss than electromagnetic steel plate. This paper reports the magnetic and mechanical properties of the magnetic composite material using Fe–Si–Al alloy, considering low iron loss. The simulation results clarified the variable magnetic flux characteristics for reducing loss at high-speed rotation by actively utilizing the magnetic saturation region of the magnetic composite material. The efficiency improvement in the high-speed region is attributed to the suppression of spatial harmonics without significantly reducing the q-axis inductance. Furthermore, the proposed motor achieves both the expansion of the high-efficiency range and relaxation of mechanical stress by increasing the thickness of the bridge part adjacent to the permanent magnet.

PurposeThis study aims to evaluate a human rights-informed dementia prevention program promoting better health and social care among older adults. In this study, the authors examined whether a dual-task training would improve cognition in healthy older adults.Design/methodology/approachIndividuals attending the systematic health education program for older adults based in Japan were recruited for study inclusion, and divided into a dual-task training group (TG) and a control group (CG). The TG underwent 90 min of a weekly dual-task training for 12 weeks. Severity of dementia was measured using the Mini-Mental State Examination (MMSE) test. Brain function was assessed using a go/no-go task paradigm, during which cerebral blood flow was additionally measured using functional near-infrared spectroscopy to quantify oxyhemoglobin (oxy-Hb).FindingsMMSE total score, number of errors in the go/no-go tasks and oxy-Hb values showed significant improvements in the TG.Research limitations/implicationsOwing to the small number of participants allocated to the CG, the results must be interpreted with caution. Replication and further validation based on large-scale, randomized-controlled trials is warranted.Practical implicationsThis study highlights potential benefits of incorporating an early prevention training for dementia into a human rights-friendly health education program.Social implicationsThis study suggests a potential means to reduce costs of social security and health care by introducing a human rights-informed dementia prevention program.Originality/valueThe results suggest that dual-task training may improve cognitive function in healthy older adults, thereby contributing to better health and improvement of social health care, based on a human rights-informed health education program for the prevention of dementia.

Abstract This laboratory‐scale study attempted performance improvement and decolourization in the high‐solid thermophilic anaerobic digestion of thermally pretreated sewage sludge, as it tends to be disturbed by ammonia inhibition and colour generation. Sewage sludge was adjusted to 7%–8% total solids (TS), and pretreated at 150°C for 1 h. The digesters were operated at 55°C and 20 days hydraulic retention time. An addition of powdered activated carbon (approximately 2% of the feed TS) significantly contributed to the removal of propionate and reduced the colour in digested sludge by about 27%. Microbial analysis detected less abundance of bacterial Synergistia and archaeal Methanosarcina and implied more hydrogenotrophic methanogenesis with the activated carbon addition. Conditioning with ferric chloride for dewatering digested sludge mitigated the colour of dewatered liquor by about 67%. Therefore, these methods were demonstrated to be effective and partly overcome the above‐mentioned problems.

This study focused on the nature of a cavitating jet issuing from a small rectangular orifice the same size as a control port in a water hydraulic spool valve. The aspect ratio of the jet exit was varied to investigate the cavitation jet behavior. The flow characteristics for each aspect ratio were measured, and the jet behavior was observed with a high-speed camera. The flow characteristics of cavitating jets are changed with the aspect ratio and cavitation number. The larger aspect ratio orifice shows a higher flow rate and larger cavitation number of inception. Visualization of a cavitating jet shows that the behavior of cavitation bubbles depends on the aspect ratio. The cavitating jet region is maintained to the same dimensionless position for all aspect ratios. In addition, the distribution and time history of luminance of the visualized images for each aspect ratio shows that the cavitation generates stably in the jet shear layer.