In this paper, we have analyzed quantum confinement effects in nanosheet MOSFETs by using a quantum drift-diffusion (QDD) model. The QDD model is a device simulator which allows to simulate quantum confinement effects in the inversion layer for advanced MOSFETs. The quantum confinement effects in nanosheets have been analyzed by comparing the simulation results by QDD and drift-diffusion (DD) model. The drain current ratio of DD to QDD is 250.1% at V_G = 0.5 V and 180.1% at V_G = 0 V. While the maximum electron density of DD exists at the interface between the insulator and the silicon sheet, that of QDD goes to near the center of the silicon sheet. The electron areal density ratio of DD to QDD is 118.3% in the direction of the 10 nm width of the silicon sheet and 176.9% in the direction of the 4 nm width.

The regenerative braking for electric vehicles is studied. The experimental device consisted of rotational load, three-phase synchronous motor, regenerative circuit and Electric Double Layer Capacitors (EDLC) as the energy storage is modeled and analyzed. Rotational kinetic energy of rotational load is converted into electric energy by regenerative motor. EDLC is charged by kinetic energy through regenerative circuit consist of switching circuit and booster circuit. In order to slow down vehicle so that drivers and passengers do not feel uneasy, the deceleration and jerk should be reduced. Therefore, deceleration is controlled by changing current value of main circuit by regenerative circuit in order to decelerate at the target deceleration when regenerative brake is applied. In addition, a regenerative braking system with high versatility and trackability to target deceleration is investigated by using PI control for regenerative circuit control, which is previously set based on the results of analysis. As a result, deceleration control in line with the target value is achieved from the start of deceleration to just before stopping. The regenerative efficiency is 11.3% and about 3% larger than the conventional system. Moreover, when the initial velocity is tripled, the regenerative efficiency is 12.3%.

DC bus systems are utilized to deliver powers to various motor loads. Inverters are placed just before motors to give appropriate powers. When the inverters are controlled to output constant powers, they may have negative impedances at the DC input bus because of constant power characteristics. This may cause a stability problem due to interactions between the inverter impedances and DC filters. This paper proposes an analytical calculation method of DC input impedance of an induction motor drive system for stability analysis by the impedance method. The developed method considers the slip control, the decoupling control, and mechanical perturbations in the small-signal model. Analysis examples by the proposed method are investigated and validated analytically and experimentally.

During sucking, the tongue undulates from the front towards the back of the tongue, showing peristaltic-like movements. We previously measured the tongue force of approximately 200 infants and have shown its dynamic properties. In this study, the movements of the infant tongue during sucking were reproduced using a four-bar linkage. We also developed a model of the oral cavity that integrated a tongue, palate, etc., including the part where a sealed is produced. The force waveforms obtained from the oral cavity model manifested the similar characteristics as those of the infant tongue. We also demonstrated that the oral cavity model could be used to measure the flow of milk.

The objective of this study is to develop a xerostomia diagnosis support system to evaluate the moistness of the oral cavity. A sensor unit was developed to measure the relative humidity by the change in voltage signal using an acrylic cylinder with an insertion of a resistive hygrometer. An artificial oral cavity that mimics the shape of a human oral cavity and oral mucosa was prepared, and the moistness of the different areas of the oral mucosa was evaluated. A statistically significant difference was observed in the time constant associated with 63% of the saturation value between the simulated healthy and dry conditions, suggesting that the oral moistness can be evaluated using the proposed system.

Recently, many parallels and distributed processing systems employing FPGAs have been proposed, and the demand from companies and laboratories has been increasing. This paper describes implementation and evaluation of distributed processing on a PCs and FPGAs hybrid system. The implemented system is capable of performing both conventional distributed processing in the PC network and distributed processing in the FPGA network. Three types of applications are implemented, and the corresponding experimental results are presented. The results demonstrate that the proposed system can use a configuration that maximizes performance or prioritizes power efficiency.

With promotion of remote work associated with the Covid-19 pandemic and expansion of the market for shared offices, introduction of a hot-desking in offices will be accelerated. Under this situation, air conditioning system is expected to operate so as to improve comfort of individual occupants according to position of occupants in a room. In this paper, we propose an air conditioning multiple point control system that determines air-conditioning setting values such that a summation of differences between zone temperatures and occupants' preferable temperatures is minimized by using thermal sensation data input by occupants. We show that this system reduced the individual’s temperature dissatisfaction and improved their comfort, both in a simulation and in an experiment on a real environment using occupant agents. In the simulation, we confirmed that the cost value, which is an index of dissatisfaction, was minimized by the proposed method in a scenario assuming an office environment. In the experiment on a real environment, we confirmed that the cost value of the proposed method was smaller than that of the comparison method, and the average difference between the occupants' preferable temperatures and the zone temperatures was reduced to about 1.0°C.

The environment surrounding the electricity system in Japan is undergoing major changes, for example, the increase in facility management costs due to the ageing of facilities, and the change in business structure due to the legal separation of the transmission and distribution sectors. Also, mass deployment of renewable energy is required. In this study, we evaluate the economic viability of a battery delivery system in which each consumer is independent of the electricity distribution network and is supplied with electricity through the delivery of cartridge storage batteries. In the battery delivery system, each consumer is equipped with the minimum necessary photovoltaic power generation equipment and storage batteries to produce and consume their own electricity. The capacity of the photovoltaic power generation system, the storage batteries, and the delivery method required to meet the electricity demand of the storage battery delivery system in depopulated areas are clarified. Also, the cost of installing the system and the cost of delivering the storage batteries are estimated to evaluate its economic efficiency.

In this paper, a new feed-back controller reduction scheme is proposed. The two-degree-of-freedom(2DOF) control system has a feed-forward controller and a feed-back controller, thereby expanding the range of feasible transfer characteristics. However, this increases the overall order of the controller. It is necessary to reduce the order in the implementation of the controller. In 2DOF control systems, it is known that the transmission characteristics change when the plant changes. A method using the Riccati equation is employed to reduce the order of the feed-back controller preserving the transfer characteristics. A numerical example is illustrated to show the effectiveness of the method.

Damage caused by crows such as damage to crops, scattering garbage on the streets, assaulting people walking beneath their nests, etc. has become a problem in various parts of the country. There are several damage abatement techniques such as protective nets, scarecrows, flashing lights, etc. However, existing methods have limited effects and are not always practical. Research using promising AI systems use expensive equipment. In this research, we propose an end-to-end real-time crow deterrent system based on the latest deep learning technology, using low-cost equipment. The proposed system detects the crow arrival and generates randomly frightening noises, including predator or bird distress calls. We conducted various experiments and confirmed the effectiveness of the proposed system.

Recently, visual inspection methods using deep learning have been proposed. In this paper, we propose a classification method using two-step deep learning. The first step is to determine whether the painting is a defect or not, and the second step is to determine the kind of painting defect. By comparing the results using various deep learning models, we show that the classification accuracy is higher than that of conventional method.