This paper aims to uncover the multilevel causes of the Fukushima nuclear disaster (March 2011) by shedding light on the history of electric utilities and nuclear power development in Japan, the ...location choice of Fukushima as a site for building a nuclear power plant, and the unwillingness of the Tokyo Electric Power Company (TEPCO) to learn. Instead of reducing the disaster's cause exclusively to the tsunami beyond “conceivable hypothetical possibilities” (souteigai), I investigate, from a historical angle, the institutional factors of nuclear development, including the industrial and government complex for nuclear development known as the “nuclear village” (genshiryoku mura). Among the four major reports conducted by fact-finding commissions, only the Kitazawa Report and the Kurokawa Report examined how the nuclear village is associated with the disaster in terms of monopolistic structure and regulatory capture. Theory based on quantitative analysis with bad assumptions and without a history might lead us to negative implications, and causal laws. If we pay attention to history and the realism of behavioral assumptions (i.e., the unwillingness to learn and the opportunism of agents), we can mitigate the risk of acting based on bad evidence, and thus increase the likelihood of forming good policies for nuclear safety.
•Nuclear development in Japan implies numerous institutions and few capabilities.•The land chosen in Fukushima would be unsuitable for a nuclear power plant.•Ecosystem governance enables us to deviate from the myth of nuclear safety.
We have carried out research and development on an earphone-type respiratory rate measuring device, earable POCER. The name earable POCER is a combination of "earable", which is a word coined from ..."wearable" and "ear", and "POCER", which is an acronym for "point-of-care ear sensor for respiratory rate measurement". The earable POCER calculates respiratory frequency, based on the measurement values over one minute, through the simple attachment of an ear sensor to one ear of the measured subject and displays these on a tablet terminal. The earable POCER irradiates infrared light using a light-emitting diode (LED) loaded on an ear sensor to the epidermis within the ear canal and, by receiving that reflected light with a phototransistor, it measures movement of the ear canal based on respiration. In an evaluation experiment, eight healthy subjects first breathed through the nose 12 times per minute, then 16 times per minute, and finally 20 times per minute, in accordance with the flashing of a timing instruction LED. The results of these evaluation tests showed that the accuracy of the respiratory frequency was 100% for nose breathing 12 times per minute, 93.8% at 16 times, and 93.8% at 20 times.
Standard methods for swallowing function evaluation are videofluoroscopy (VF) and videoendoscopy, which are invasive and have test limitations. We examined the use of an earphone-type sensor to ...noninvasively evaluate soft palate movement in comparison with VF. Six healthy adults wore earphone sensors and swallowed barium water while being filmed by VF. A light-emitting diode at the sensor tip irradiated infrared light into the ear canal, and a phototransistor received the reflected light to detect changes in ear canal movement, including that of the eardrum. Considering that the soft palate movement corresponded to the sensor waveform, a Bland–Altman analysis was performed on the difference in time recorded by each measurement method. The average difference between the time taken from the most downward retracted position before swallowing to the most upward position during swallowing of the soft palate in VF was −0.01 ± 0.14 s. The Bland–Altman analysis showed no fixed or proportional error. The minimal detectable change was 0.28 s. This is the first noninvasive swallowing function evaluation through the ear canal. The earphone-type sensor enabled us to measure the time from the most retracted to the most raised soft palate position during swallowing and validated this method for clinical application.
In this study, an earphone-type interface named "earable TEMPO" was developed for hands-free operation, wherein the user can control the device by simply pushing the tongue against the roof of the ...mouth for about one second. This interface can be used to start and stop the music from a portable audio player. The earable TEMPO uses an earphone-type sensor equipped with a light emitting diode (LED) and a phototransistor to optically measure shape variations that occur in the external auditory meatus when the tongue is pressed against the roof of the mouth. To evaluate the operation of the earable TEMPO, experiments were performed on five subjects (men and women aged 22-58) while resting, chewing gum (representing mastication), and walking. The average accuracy was 100% while resting and chewing and 99% while walking. The precision was 100% under all conditions. The average recall value of the five subjects was 92%, 90%, and 48% while resting, masticating, and walking, respectively. All subjects were reliably able to perform the action of pressing the tongue against the roof of the mouth. The measured shape variations in the ear canal were highly reproducible, indicating that this method is suitable for various applications such as controlling a portable audio player.
We have developed an interface (mouthwitch) for a head-mounted type camera with which pictures can be taken with a head-mounted camera, hands-free, simply by "opening your mouth continuously for ...approximately one second and then closing it again". This mouthwitch uses a sensor equipped with an LED and photo transistor on the temple to optically measure the changes in the form of the temple that occur when the mouth is opened and closed. Eight test subjects (males and females aged between 21 and 44 years old) performed evaluation tests using this mouthwitch when resting, speaking, chewing, walking, and running. The results showed that all test subjects were able to open and close the mouth, and the measurement results pertaining to the temple shape changes that occurred at this time were highly reproducible. Additionally, the average value for
obtained for the eight test subjects through the verification tests was 100% when resting, chewing, or walking, and 99.8% when speaking or running. Similarly, the average values for
were 100% for all items, and the average values for
were 100% when resting or chewing, 98.8% when speaking, 97.5% when walking, and 87.5% when running.
(1) Background: A mouth-free interface is required for functional electrical stimulation (FES) in people with spinal cord injuries. We developed a novel system for clenching the human ...metacarpophalangeal (MP) joint using an earphone-type ear canal movement sensor. Experiments to control joint angle and joint stiffness were performed using the developed system. (2) Methods: The proposed FES used an equilibrium point control signal and stiffness control signal: electrical agonist–antagonist ratio and electrical agonist–antagonist sum. An angle sensor was used to acquire the joint angle, and system identification was utilized to measure joint stiffness using the external force of a robot arm. Each experiment included six and five subjects, respectively. (3) Results: While the joint angle could be controlled well by clenching with some hysteresis and delay in three subjects, it could not be controlled relatively well after hyperextension in the other subjects, which revealed a calibration problem and a change in the characteristics of the human MP joint caused by hyperextension. The joint stiffness increased with the clenching amplitude in five subjects. In addition, the results indicated that viscosity can be controlled. (4) Conclusions: The developed system can control joint angle and stiffness. In future research, we will develop a method to show that this system can control the equilibrium point and stiffness simultaneously.
In this study, we describe a technique for estimating meal times using an earphone-type wearable sensor. A small optical sensor composed of a light-emitting diode and phototransistor is inserted into ...the ear hole of a user and estimates the meal times of the user from the time variations in the amount of light received. This is achieved by emitting light toward the inside of the ear canal and receiving light reflected back from the ear canal. This proposed technique allowed "meals" to be differentiated from having conversations, sneezing, walking, ascending and descending stairs, operating a computer, and using a smartphone. Conventional devices worn on the head of users and that measure food intake can vibrate during running as the body is jolted more violently than during walking; this can result in the misidentification of running as eating by these devices. To solve this problem, we used two of our sensors simultaneously: one in the left ear and one in the right ear. This was based on our finding that measurements from the left and right ear canals have a strong correlation during running but no correlation during eating. This allows running and eating to be distinguished based on correlation coefficients, which can reduce misidentification. Moreover, by using an optical sensor composed of a semiconductor, a small and lightweight device can be created. This measurement technique can also measure body motion associated with running, and the data obtained from the optical sensor inserted into the ear can be used to support a healthy lifestyle regarding both eating and exercise.
In order to design a work environment that improves office workers’ intellectual productivity, the authors have focused on airflow, which is a key factor in thermal environments. An airflow control ...method that improves the degree of concentration is proposed, and its effectiveness is evaluated objectively and quantitatively by evaluative experiments. The designed airflow environment is composed of two airflow components: a stimulative airflow and a mild airflow. In this experiment, cognitive tasks are given to participants. The concentration time ratio (CTR), which is a quantitative and objective evaluation index of the degree of concentration, is measured. The results show that the average CTR under the proposed airflow condition is 61.1%, while that under the no airflow condition is 54.6%. The proposed airflow control shows a significant improvement in CTR, with an increase of 6.5% (p < 0.001). Consequently, our findings suggest that intellectual work can be performed better in an environment that fosters a high concentration time ratio.
•Indoor environmental control that improves concentration during intellectual work.•Objective/quantitative index of concentration to evaluate intellectual productivity.•Proposing concentration-improving airflow composed of two types of control.•Effectiveness of the proposed airflow control validated by subject experiment.•Degree of concentration improved by 6.5% under the airflow control (p < 0.001).
In recent years, due to the prevalence of virtual reality (VR) and human-computer interaction (HCI) research, along with the expectation that understanding the process of establishing sense of ...ownership, sense of agency, and limb heaviness (in this study, limb heaviness is replaced with comfort level) will contribute to the development of various medical rehabilitation, various studies have been actively conducted in these fields. Previous studies have indicated that each perceptual characteristics decrease in response to positive delay. However, it is still unclear how each perceptual characteristic changes in response to negative delay. Therefore, the purpose of this study was to deduce how changes occur in the perceptual characteristics when certain settings are manipulated using the avatar developed in this study. This study conducted experiments using an avatar system developed for this research that uses electromyography as the interface. Two separate experiments involved twelve participants: a preliminary experiment and a main experiment. As observed in the previous study, it was confirmed that each perceptual characteristics decreased for positive delay. In addition, the range of the preliminary experiment was insufficient for the purpose of this study, which was to confirm the perceptual characteristics for negative delay, thus confirming the validity of conducting this experiment. Meanwhile, the main experiment showed that the sense of ownership, sense of agency, and comfort level decreased gradually as delay time decreased, ( i.e. , this event is prior to action with intention, which could not be examined in the previous study). This suggests that control by the brain-machine interface is difficult to use when it is too fast. In addition, the distribution of the most strongly perceived settings in human perceptual characteristics was wider in regions with larger delays, suggesting this may lead to the evaluation of an internal model believed to exist in the human cerebellum. The avatar developed for this study may have the potential to create a new experimental paradigm for perceptual characteristics.
We intend to develop earphone-type wearable devices to measure occlusal force by measuring ear canal movement using an ear sensor that we developed. The proposed device can measure occlusal force ...during eating. In this work, we simultaneously measured the ear canal movement (ear sensor value), the surface electromyography (EMG) of the masseter muscle and the occlusal force six times from five subjects as a basic study toward occlusal force meter development. Using the results, we investigated the correlation coefficient between the ear sensor value and the occlusal force, and the partial correlation coefficient between ear sensor values. Additionally, we investigated the average of the partial correlation coefficient and the absolute value of the average for each subject. The absolute value results indicated strong correlation, with correlation coefficients exceeding 0.9514 for all subjects. The subjects showed a lowest partial correlation coefficient of 0.6161 and a highest value of 0.8286. This was also indicative of correlation. We then estimated the occlusal force via a single regression analysis for each subject. Evaluation of the proposed method via the cross-validation method indicated that the root-mean-square error when comparing actual values with estimates for the five subjects ranged from 0.0338 to 0.0969.
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