Many people use the Internet which are connected by cables between terminals. For this reason, it may be crowded and not connected in the event of a disaster or emergency. It also has weaknesses that make it vulnerable to natural and human threats. This is a problem for the communication line of the local government office. Therefore, we propose a self-employed radio propagation path that can be constructed at low cost. An MCA line was set up for the outdoor trunk line, and an LPWA line was set up for communication inside the disaster stockpile storage building. An experiments were conducted in a university campus building. In order to obtain the effectiveness, we moved inside the building to find the optimum threshold. As a result, we were able to obtain feasible data. As a result of performance experiments with Wi-Fi and LPWA, it was found that LPWA is superior to Wi-Fi.

In recent year, the number of care recipients has been increasing due to the aging has progressed. Mild care recipients have to do activities of daily living by myself, e.g. get up from bed, stand-up and sit-down motion, walking in home, brush teeth and so on. In previous study, a support system to assist the standing and sitting motion of care recipients has been proposed and Effectiveness of a seat rotation mechanism in support system was verified. The purpose of this study, the effectiveness a support system with a handrail is evaluated by a comparing waist and knee joint torques with and without handrail. In both cases stand-up and sit-down, the maximum torque of hip and knee joint can be reduced by using the handrail.

This paper proposes a full-order observer based generalized minimum variance controller equivalent to polynomial approach. Although the controller using the reduced-order observer has the equivalence, the controller cannot be extended to the generalized stabilizing controller. This paper modifies a full-order observer and proposes an equivalent controller.

This paper considers an interpolated distributed cooperative observer design and its online update for the situation that intelligent transport systems (ITS) and vehicles estimate vehicle platoons' positions in a two-dimensional plane. ITS observes some vehicles' absolute positions, and each vehicle interpolates its position based on the observed relative distance to the surrounding vehicles and the vehicles' estimated position. The observers of each vehicle use the interpolated positions to estimate their vehicles' positions. The interpolated positions are updated depending on the communication status of the surrounding vehicles using sparse modeling. We provide a distributed search algorithm to generate the shortest communication path that can share the estimated position among the observers in a short time. These methods enable us to estimate the distributed position of vehicle platoons under the condition that the positional relationship between vehicles changes on a two-dimensional plane.

For the data driven control, optimization of functions distribution on the IoT platform is important issue. In this paper, online re-tuning of PID parameter by dynamics' health indexes is described. In this technique, function elements are distributed to a local PID controller and an edge computer. For detecting the dynamics' indexes, the local PID controller operates as a detector.

In this paper, we designed a fault-diagnosis system using a multilayer perceptron for a multi-agent consensus control system. The proposed system diagnoses the presence or absence of a fault and the faulty agent, based on the fault features called residual signals. The residual generator and the fault-tolerant controller are designed based on the conventional method using H∞ and H- norm of the transfer function about the fault signal. A numerical simulation was performed to confirm the effectiveness of the proposed method.

A stable control system is easily designed with the simple adaptive control (SAC) method by using the almost strictly positive real (ASPR) condition of a plant. For the plant that does not satisfy ASPR, an SAC system can be designed by adding a parallel feed-forward compensator (PFC) to the plant. However, in this case, steady-state error between the plant output and the reference model output may remain because of the PFC output. To solve this problem, the null-space adjustor which cancels the PFC input on the steady-state of the system, has been proposed. In our study, an SAC system with the null-space adjustor was extended using a disturbance compensator. We showed the boundedness of the signal in the proposed SAC system and confirmed the effectiveness of the proposed method by the numerical simulation.

Centimeter-Level Augmentation Service (CLAS) started from Nov.1,2018 with a four-satellite constellation of the Quasi-Zenith Satellite System (QZSS). In CLAS, Centimeter Level Augmentation Information including correction and integrity information is allocated to the QZSS L6 signal and broadcast to users available for the major part of Japan. CLAS infrastructure system has increased the maximum number of satellites included in the Centimeter Level Augmentation Information to be from 11 to 17. Therefore, it seems that even if a dual-band low-cost receiver will have positioning performance comparable to that of a triple-band receiver. This paper attempts to evaluate the positioning performance of CLAS using a dual-band low-cost GNSS receiver. The experimental results show that the AQLOC-Light compatible post-processing software using a dual-band low-cost receiver performs as well as triple-band GNSS receiver. These findings contribute further to the development of a CLAS positioning system.

In this study, a skill-based method which can score an operation of a construction machinery is proposed and verified that it has an effectiveness for quantitative evaluation of beginners' operation skill. Proposed method calculates a score of a construction machinery operation based on skilled data of an expert operator. Efficient training of beginners for skill transfer can be expected by using the quantitative evaluation results.

In Japan, the 5th Science and Technology Basic Plan proposed Society 5.0 as the new vision of society. However, according to future estimates of IT human resources, there will be a shortage of about 590,000 people by 2030. Given this situation, it is necessary to develop human resources who can solve problems and create value with a basic background in mathematics and data science. It is also necessary to provide data science education throughout elementary school, junior high school, and high school, and to provide it regardless of humanities or science. In this paper, we developed, practiced, and verified the effectiveness of education for designing programs using modeling based on the concept of data science in junior high school technology education.

In this paper, we propose a method to achieve a given desired tracking property with only minimal information on the control target by combining FRIT with some extensions to the intelligent PID control system. The intelligent PID control system has a simple structure and can stabilize a system using only parameters without requiring much dynamic characteristics of a control target. Here we firstly extend the intelligent PID to Proportional differentiel leading typed PID controller, which is abbreviated as iI-PD controller, to guarantee the stability of the closed loop for broader class of plants compared with the original inteliggent PID control systems. Secondly, we apply FRIT to decide the parameters of a controller with only one-shot experiment to follow the desired response. Thus, by combining FRIT, we obtain controller parameters which is adjusted so that it enable not only output to follow the desired response but also guarantee the stability of the closed loop system with only an initial experimental data. We also verify the effectiveness of the proposed method with numerical examples.

Policies are being promoted to realize Society 5.0, which is Japan's vision of the future society. As a part of AI education, there is a need to enhance programming education at the primary and secondary education levels. Many teaching materials for learning programming have been proposed. On the other hand, from the perspective of fostering student competency, it is important to use ICT to monitor their learning situation and provide them with individualized instruction and support. This paper explains a method for quantitatively evaluating the proficiency process of programming skills. First, the learning tasks of programming in technology education will be explained. Next, the method for obtaining the learning result data will be explained. Next, show the results of learning tasks that the students worked on. Finally, consider showing the results in a graph or trade-off curve to quantitatively evaluation the students' skill level.

We are developing devices that apply a linear equation mechanism in which three joints are coupled with a differential mechanism through continuously variable transmissions (CVTs). One of these devices is an adjustable lift cart in which three joints are connected to two axes of the left and right wheels of the cart and to one axis that lifts the cart's loading platform. The adjustable lift cart can lift the loading platform up or down to a desired height while it is moved horizontally by human power. The cart's loading platform moves forward and upward (or downward) as if it is on a virtual guiding surface. Until now, the virtual guiding surface generated by the linear equation mechanism has been a flat surface defined by a single normal vector. In this work, we show that not only flat but also curved surfaces can be generated by setting the normal vector as a function of the displacement or velocity of the cart.

This paper considered a design method of a reference governor which is used to improve control response by changing the reference input to the controller without changing the controller under the input restriction. In previous studies of reference governors, online reference governors using model predictive control have been proposed. However, it is necessary to solve a constrained optimization problem repeatedly to apply such online reference governors. To solve this problem, we employed the particle swarm optimization method which is an evolutionary computation method known for its fast solution search to design online reference governor. The effectiveness of the proposed method was confirmed by a numerical simulation.

Threat modeling is a process to determine effective cybersecurity measures to secure industrial control systems (ICSs). However, deep cybersecurity knowledge is required to perform threat modeling processes and those results including prioritization of cyber attack scenarios are depended on security analysts. To reduce the dependency of analysts, it is required to express cyber attack scenarios with a structured model. In this study, a new structured model that expresses cyber attack scenarios for ICSs is proposed. The proposed model is based on the Diamond model and capable of expression behaviors of adversary in a targeted system by a structured form. The model makes it possible to express structured cyber attack scenarios and reduce dependency of analysts. This paper provides a detail of the proposed model and evaluation results of the model in terms of the usefulness of threat modeling.

In this research Markov decision process is applied to infectious disease control. A new infectious disease control method which maximizes the probability of staying in objective states under a limited budget is proposed. The effectiveness of the proposed method is shown by some computational examples.

The impact of the growth order on the Sb diffusion from compositionally-graded-InGaAsSb/highly-doled-GaAsSb base of double heterojunction bipolar transistors (DHBTs) is discussed in this paper. For the conventional emitter-up DHBT wafer, the shift of x-ray diffraction peak of InGaP emitter due to the incorporation of a few percent of Sb is found. On the other hand, there are no pronounced peak shift when the growth order is inverted for the transfer-substrate (TS) DHBTs. Transmission electron microscopy reveals that the abruptness of the emitter-base interface of conventional wafer and base-collector interface of the wafer for the TS-DHBT are degraded. This interface degradation is due to the Sb diffusion into the upper layer of GaAsSb/InGaAsSb base.

In previous report, we showed that the source-drain leakage current at off state can be suppressed by thinning the undoped channel layer even if the gate length was reduced to 25 nm in device simulation of AlGaN/GaN HEMT. On the other hand, if the source-drain leakage current can be suppressed, leak current is dominated by the leakage current between the gate and drain. In this report, the source-drain leakage current and the gate-drain leakage current are calculated when drain voltage is until 50 V. When the sufficiently small access resistance is assumed, change of Al composition of barrier has almost no effect in DC characteristics, while the gate-drain leakage is suppressed when Al composition is lower due to lower polarization charge at heterojunction. To use high Schottky barrier height of the gate of AlGaN layer with high Al composition effectively, reduction of the density of polarization charge by using semi-polar-face is proposed.

GaN-on-diamond high electron mobility transistors (GaN-on-diamond HEMTs, GoD HEMTs) were successfully fabricated using a large size mosaic diamond substrate. A mosaic diamond with size of 15mm×15mm was prepared and finely polished using novel polishing technique utilizing hydroxyl radicals generated through the catalytic reactions between transition-metal and hydrogen peroxide. GaN-based thin film which contains HEMT patterns were separated from the original substrate and finely polished. Both polished surfaces were bonded using surface-activated room temperature bonding technique with inserting very thin interfacial layer. Measured current-voltage characteristics and temperature imaging results showed that heat transition through the substrate in the fabricated GoD-HEMT improved drastically compared to the HEMT device fabricated using GaN-based thin films grown on Si substrate.

We fabricated ultra-broadband integrated optical front-end module included InP analog multiplexer ICs and Mach-Zehnder modulator. In addition to the ultra-broadband characteristics of those InP devices, we carefully designed the substrate and interconnection of the module for minimizing the loss derived from assembling. As a result, the module revealed broad EO response of 80 GHz. We successfully generated QPSK signal at the speed of 192 GBaud and demonstrated a 1.3 Tb/s/λ optical transmission (168-GBaud PDM PS-64 QAM) with this module.

The local electric field distributions inside specimens can be directly observed by differential-phase-contrast scanning transmission electron microscopy (DPC STEM). In this study, we applied DPC STEM to GaN/AlGaN/InGaN multi-heterostructures. We successfully visualized the differences in electrostatic potentials of GaN/AlGaN/InGaN.

Traditional multi-objective branch-and-bound approaches to multi-objective mixed-integer linear programming (MOMILP) problems are very expensive to search due to the huge number of Pareto-optimal solutions. In this research, we propose a practical method of dividing a multi-objective problem into multiple single-objective problems by weight vectors and applying the branch-and-bound method (BB) to each subproblem. The proposed method is named multi-objective branch-and-bound based on decomposition (MOBB/D) because it is a combination of the concept of multi-objective evolutionary algorithm based on decomposition (MOEA/D) and BB. The most important feature of MOBB/D is to obtain many Pareto solutions efficiently by sharing information between nearby subproblems in MOMILP problems. In this paper, we describe an approach to share tables in the simplex method as an example of information. Moreover, MOBB/D can control computation cost for solving MOMILP problems by adjusting the number of obtained Pareto solutions. To verify the effectiveness of the proposed method, we compared the search performance of MOBB/D with and without the use of neighborhood information.

The Ministry of Education, Culture, Sports, Science and Technology (MEXT) has called for educational institutions to realize “independent, interactive, and deep learning” in order to develop the qualities and abilities necessary for children to live in the human-centered society (Society 5.0) that Japan aims to establish in the future. As a result, active learning, such as group discussions, is becoming more common in school education. However, quantitative evaluation indicators and methods have not been established to show whether “deep learning” has been achieved or not. In this study, we propose a method to quantify the depth of learning based on the features extracted from the content of the students' comments in group discussions using the Revised Taxonomy, and to present the results to the teacher.

This paper reports demonstration and application of web-based Visual Compiler to practical computer education. Our Compiler can run on major browsers of various operating systems because it is implemented in HTML5 and JavaScript. It can provide educational visualization for the internal processing of the compiler. One of the purposes of this educational tool is to promote understanding of language processing and behavior of compiler from C-like compiler language into pseudo assembly language. Its internal structure is composed of the following four parts: input part for Replacehigh-level programmingcompiler language statements, lexical analyzer, syntax analyzer, and code generator. Our compiler supports the following practical computer education together with CPU simulator: 1) visualization of compiling process from compiler language into related assembly code graphically, 2) illustration of executing process of each assembly instruction by CPU simulator, and 3) verification that user writing compiler language program can be computed and correctly terminated by CPU. We have demonstrated example lecture of computer education with our compiler and carried out questionnaire about lecture with compiler. Qualitative and quantitative evaluation of our compiler has been affirmatively performed by means of positive results of questionnaire about our education.

Mode-locked fiber lasers are gaining a lot of attention in the industry because of their excellent performance while being relatively inexpensive. Although fiber ring is robust and has been widely used, it only achieves a repetition rate of several hundreds of MHz due to the long fiber needed to build the resonator. On the other hand, Whispering-Gallery-Mode (WGM) microresonators can achieve an extremely high repetition rate due to the smallness of the device. We explore the possibility of a passively mode-locked laser with CNTs as a saturable absorber and erbium-doped microresonator.

This paper presents a formulation of an optimization of uncertain systems and the solution technique. The optimization under uncertainties is formulated as an optimization problem which includes unknown variables in equality constraints called system equations as well as in an objective function and inequality constraints. As countermeasures against the uncertainties, a min-max criterion is applied to the objective function and robustness criteria are introduced to the inequality constraints. By differentiating state variables satisfying the equality constraints from the decision variables, we reformulate the optimization problem based on the worst case scenario of the state variables corresponding to the uncertain variables and we propose a “constraints-relaxation procedure” based method considering the equality constraints to solve the reformulated problem. In this method, a constraints-relaxed problem is solved corresponding to a finite number of samples of uncertain variables. Furthermore, a new sample of uncertain variables is sequentially generated corresponding to the inequality constraint which the solution violates most, together with state variables satisfying the system equations at the new worst-case scenario. Finally, the effectiveness of the proposed method is illustrated by numerical examples including robust AC optimal power flow considering distributed energy resources.

In rehabilitation from motor paralysis, it is important to provide appropriate sensory feedback that the body moves as desired. Appropriate feedback causes synchronous neuron firing, resulting in the recovery of function. The idea of making the system move as desired has long been studied as manual control. In this paper, based on the results of considering the systems necessary for motor rehabilitation from the viewpoint of manual control, we constructed a motor rehabilitation system in which the cursor on the display moves by sticking out the tongue for dysphagia, and conducted experiments. As a result of the experiments with healthy participants, we were able to confirm the validity of the assumption of a simulation that human is linear systems with a primary delay-system. By adding a learning compensator to the system, we were able to make the cursor follow an ideal trajectory. On the other hand, a problem was found that start-up tracking near the target value was an issue. This was due to the non-negligible amount of dead time in the human and the system, and the fact that a lot of noise was introduced due to the characteristics of the system.

In recent years, accidents caused by people using their phones while driving are becoming a social problem. Previous researches have proposed some methods to recognize operations other than driving by using a camera that shoots the driver, but there are also drivers who dislike regular video recording of his face and pose. Therefore, for the spread of the system, it is necessary to detect the distracted driving from vehicle behavior without the driver’s image. Nevertheless, there is not much research to constantly detect the distracted driving from the behavior of the vehicle. In this research, we propose the method to detect the distracted driving focusing on correction steering for lateral sway of the vehicle. Information about lateral sway of the vehicle is calculated from the lateral acceleration acquired by the digital tachograph. And we evaluated the accuracy of distracted driving detection by experiments with driving simulator and actual vehicle.

A data restoration method for the large-scale disasters is proposed. Recently, social data, e.g. resident information or medical information, are stored into information systems. The social data are backed up to remote site to protect from data loss. It is important for restoration to be able to utilize the backup data as soon as possible. Thus, a part of backup data, e.g. files, is individually restored (File-lvl Restore). To reduce the time to get backup data by the File-lvl Restore more further, we apply the parallel data downloading. However, the current method does not consider the TCP slow-start processing; thus, the number of chunks of parallel downloading becomes insufficient. In this paper, we propose a data restoration method that decides the number of chunks based on Round Trip Time and the characteristics of TCP slow-start. Our evaluation results show that the time to get the backup data by using the proposed method becomes 1/2 to 1/3 compared to the current method.

When the instantaneous frequency is estimated for a single sine wave using a finite-order Hilbert transformer, the estimated value contains an oscillation component that is an even multiple of the input signal frequency. However, the conventional method does not take into account the aliasing that occurs in the oscillation component. In this paper, we show that designing a variable filter that takes into account the aliasing of the oscillation component can achieve higher estimation accuracy.