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Recently the wireless surveillance system has been regarded highly. In order to realize the sensitive wireless surveillance system, its antenna has to perform the broadband and high gain characteristics. As the simple method, it can be realized to combine the parabolic reflector and the broadband primary antenna which has the wide and constant beam width through the wide frequency band. This time, we have tried to develop the broadband and wide beam width antennas composed of the corrugated lens and the ridged antenna as the primary antenna for the parabolic reflector. This paper introduces its configuration and the good simulated results as follows.

Under the circumstances that social robots are increasingly being developed and studied in service encounters at public spaces, are they introduced into residential environments (i.e., private space)? This study hypothesizes that a personal assistant device in residential environments should wear human-like appearance to engage in service as conversation partner. We implemented the interaction design that provides regular services as the current personal assistant and additional service as conversation partner, and then conducted a field experiment where the participants stayed in the hotel rooms with a smart speaker or a social robot. The results support the hypothesis in that of conversation amount and emotional experience by conversation. The results also suggest the possibility of commercial service, namely conversational advertisement through social robots.

Loop-closure and map-combiner detection is very important to robustly enable applying SLAM technology and generate high-definition maps in level of cities and prefectures. In addition, the detection process paves the way to evaluate the map quality at the revisited areas in terms of relative and global position errors. Accordingly, this paper proposes a unique framework for precisely detecting loop-closure and map-combiner events regardless to the driving trajectory, the vehicle sensor configurations and the environment structure. A very challenging environment including long underground tunnel and multilayer junction has been selected to emphasize the reliability, scalability and robustness of the proposed framework. The experimental results have verified the capability to detect the map-combiner events precisely even-though with the existence of a considerable low positioning accuracy by a GNSS/INS-RTK system.

Petrobras is Brazil’s largest publicly-held company, operating in the oil, natural gas, and energy industry. Internal efforts enabled Petrobras to identify Digital Transformation (DT) opportunities to further promote their operational excellence. While addressing these opportunities typically requires Research and Development (RD (ii) parallel technical feasibility assessment and conception phases, allowing to ‘fail fast’; (iii) scrum-based development management; and (iv) strategically aligned continuous experimentation to test business hypotheses. We report on first experiences of applying Lean R&D in practice. [Results] Lean R&D enabled addressing research-related uncertainties early and to efficiently deliver valuable MVPs within fast-paced four months cycles. [Conclusions] In our first experiences Lean R&D showed itself suitable for supporting DT initiatives. However, more formal case studies are needed. The business strategy alignment and the continuous support of a highly qualified research team were considered key success factors.

The new definition of the kilogram based on the Planck constant was implemented in May 2019. The National Metrology Institute of Japan (NMIJ) will realize the new kilogram by the X-ray crystal density method using a 28Si-enriched sphere. An international comparison of the realizations of the new kilogram by national metrology institutes was organized. As a participant in the comparison, the NMIJ realized the kilogram by the volume measurement and surface characterization of a 28Si-enriched sphere. Details of the measurement results and the uncertainty evaluation of the realization are described. The comparison of the realization results with previous realization results in 2016 is also provided.

The kilogram based on the Plank constant will be realized at the National Metrology Institute of Japan (NMIJ) by using the X-ray crystal density method. In this study, for the realization, the volume of a 28Si-enriched sphere, named AVO28-S5c, was measured. The volume was determined from diameter measurements taken in many directions using an optical interferometer. The apparent volume of the sphere, which does not consider the influence of the surface layers on the volume measurement, was determined with a relative standard uncertainty of $1.8\times 10^{-8}$ . The reproducibility of the kilogram realization is important for the reliable dissemination of the kilogram at the NMIJ. Therefore, the volume determined in this study was compared with that determined in 2016. These volumes were shown to agree with the uncertainty. This article provides details on the measurements, improvements of the interferometer, data analysis, and uncertainty evaluation.

To realize the kilogram using the X-ray crystal density method, 28Si crystals grown by the floating zone method are used. Samples prepared from AVO28 crystal and a new crystal, with surfaces etched in Tetramethylammonium hydroxide solution, were analyzed by electron paramagnetic resonance (EPR) spectroscopy. The EPR signals from vacancy defects were found to be below the detection limit of $1\times 10^{12}\ \mathrm{cm}^{-3}$ , which suggests that the corresponding corrections for the realization of the kilogram are equal $0.0(2)\ \mu \mathrm{g}$ . We conclude that the vacancy defects do not account for the discrepancy of $39(21)\ \mu \mathrm{g}$ between the kilograms realized using the two crystals.

The precision measurement of radiation pressure force, especially in a manner traceable to the International System of Units (SI) is of importance. For the precision measurement of radiation pressure of optical laser, a voltage balance which uses electrostatic force between electrodes has been developed at the National Metrology Institute of Japan (NMIJ). The voltage balance enables mass and force measurements traceable to the new definition of the kilogram. To confirm the reliability of the balance, the mass of a 2 mg wire weight was determined. The relative standard uncertainty of the mass measurement was estimated to be $8.4\times 10^{-4}$ . The mass of the weight was also measured by a commercially available electronic balance. The masses determined by the two different methods were in agreement within their uncertainties. Details on the measurement system and result are presented.

The objective of this study is to understand the learned-strategy of neural network-controlled robots in relation to their physical learning environments by visualizing the internal layer of the neural network. During the past few years, neural network-controlled robots that are able to learn in physical environments are becoming more common. While they can autonomously acquire strategy without human supervisions, it is becoming difficult to understand their strategy, especially when the robots, their environments and their tasks are complicated. In the critical fields that involve human safety, as in self-driving vehicles or medical robots, it is important for human to understand the strategies of the robots. In this preliminary study, we propose a hierarchical neural network with a two-dimensional topographical internal representation for training robots in physical environments. The 2D representation can then be visualized and analyzed to allow us to intuitively understand the input-output strategy of the robots in the context of their learning environments. In this paper, we explain about the learning dynamics of the neural network and the visual analysis of some physical experiments.

In this study, we attempted to classify the sex of salmon using a convolutional neural network. We collected labeled(male/female) images of salmon and other fishes, and trained the VGG16 type neural network by implementing several data argumentation techniques, cropping the bounding box of salmon. In evaluation, the F value of the classification result was found to be satisfactory by more than 99%. We demonstrated the focus point of the neural network using Grad-CAM and the classification ability depending on the background processing.

This paper presents a simple and efficient method for finding all characteristic curves of piecewise-linear resistive circuits using integer programming. In this method, the problem of finding all characteristic curves is formulated as a mixed integer programming problem, and it is solved by an integer programming solver CPLEX. It is shown that the proposed method can be implemented easily without writing complicated programs. It is also shown that all characteristic curves are obtained by solving a mixed integer programming problem only once. Numerical examples are given to confirm the effectiveness of the proposed method.

Wireless power transfer (WPT) has been realized by Teslacoil by Nicola Tesla since 1889. In recent years, WPT is often used for charging laptops and smartphones, and their output is approximately 10 W to 100 W. On the other hand, for the Electric Vehicle (EV) charging several kilowatts transfer is required in WPT. WPT has advantages such as no exposure of contacts, no sparks when connecting terminals, and no wear of contacts. These advantages make it ideal for charging electric vehicles. However, in the magnetic induction method that has been conventionally used, the transmission distance is short. On the other hand, in the Strong Coupled Magnetic Resonance (SCMR) method proposed in 2010 by MIT, the long distance power transmission is succeeded. [1]. However, the resonant coil used in [1] has a large volume due to its height. In addition, there is no example of high power transmission by using this method. In this paper, a high power thin antenna using 13.56 MHz, which can apply to EV charging, is proposed. The theory is confirmed by some experiments. As a result, the maximum antenna efficiency 93.4%, and maximum power 2.4kW transmission with 84.0% efficiency is realized under 300mm power transmission distance with 3.2mm coil thickness.

This paper describes 2.4 GHz RF peer-to-peer propagation measurements and modeling in a Japonica paddy field during 5 stages of the growth season: transplantation, panicle initiation, booting, flowering, and grain filling. From the perspective of practicality for the various setting conditions of a sensor unit, the antenna heights were placed 55,105 and 155 cm from the ground in order to evaluate signal propagation through vegetation. Detailed measurement curves of RSSI (received signal strength indication) against distance indicate the presence of various vegetation types based on the moisture conditions of plant growth. The SRET (simplified radiative energy transfer)-based model fits well depending on leaf density for NLOS (non-line-of-sight) conditions. In the case of LOS (line-of-sight) conditions, a novel model named the “TRPF (two-ray paddy field) model” is proposed in order to express the influence of vegetation for a reflection wave.

In this paper, we considered applying the simple games “CogState Research” to our methodology for elucidating the activation/inactivation mechanisms of maternal brain functions. Forty healthy subjects were recruited from women living in Tokyo and the surrounding area, Japan. Ten were not pregnant (mean age ± SD: 21.1 ± 0.7) and 30 were postnatal. As it turned out, the postnatal subjects were divided into three groups (n=10) in accordance with the progress of their child raising: within only a year (mean age ± SD: 33.0 ± 3.8), one and a half years (mean age ± SD: 33.6 ± 4.1), and approximately two years (mean age ± SD: 36.9 ± 4.7). All the postnatal subjects were delivered of their first child. To begin with, we investigated variations in a woman’s cognitive function after a time of childbearing, employing simple card games and a Groton Maze task. Secondly, hemodynamic changes at the prefrontal areas were measured using a multi-channel functional near-infrared spectroscopy (fNIRS) apparatus equipped with 3×5 probes (22 ch). For the fNIRS measurements, we used two hearing tasks: the sound of baby crying, and the Chopin’s nocturne as a control. Finally, we evaluated the changes of our subjects’ emotional states in chronological order after their time of childbearing. The accuracies relating to OC learning in the postnatal women with one and a half years after childbearing were significantly higher, as contrasted with the nonpregnant ones (P < 0.01). Furthermore, speed to GMLT task in the postnatal group was significantly higher, as contrasted with the nonpregnant one (P < 0.01). In the results of our fNIRS data for the postnatal women, we detected the correlations between cognitive functions and prefrontal hemodynamics corresponding to functional changes in a women’s hearing, as contrasted with the data results for the nonpregnant ones. Our findings support the idea that postnatal women’s cognitive functions are closely connected with memory as well as their prefrontal hemodynamics corresponding to functional changes in female hearing capabilities.

This paper introduces a Graph Slam framework for improving the accuracy of elevation-maps. The core-idea is to utilize LIDAR images in determining the relationships between the road nodes and calculate the relevant elevation constraints. Phase correlation is applied to estimate the common areas between the nodes and confirm the loop-closure events. The dead-reckoning altitudinal measurements are used to initialize the graph in order to avoid the low GPS quality and guarantee a smooth change of the map consistency. The generated elevation-maps have been compared with the GPS-RTK maps using a reliable evaluation scheme. The results have verified that the proposed method can produce elevation-maps at the same accuracy level of GPS-RTK maps in open-sky area. Moreover, it significantly recovers the low accuracy of GPS-RTK maps in critical environments. Accordingly, the generated maps can safely be used during autonomous driving with better estimation of the vehicle altitudinal position.

A millimeter-wave presystem is a system whose RF part is composed of a set of RF modules of element circuits connected via waveguides instead of being composed of an MMIC. Introducing the millimeter-wave presystem enables to shorten overall development period because the millimeter-wave presystem can be built at an early stage of MMIC development and therefore the application development can be started earlier by using the presystem. To build the millimeter-wave presystem, on-board impedance matching circuits are essential to suppress return loss in each RF module. This paper describes the design of an on-board impedance matching circuit for 79GHz millimeterwave presystem. To ensure simulation accuracy, the bonding wire, PCB, and IC in the RF module were separately modeled to fit with measured data. The on-board impedance matching circuit was designed by using these models. Owing to these accurate models, the fabricated impedance matching circuit achieved a return loss smaller than −10dB.

A novel Circuit Under on-chip-inductor structure (CUL) including high-Q inductor (Q peak > 19) formed in the redistribution layer (RDL) is proposed to reduce the chip-size of RF embedded MCUs/SoCs. A design methodology for the CUL implementation without degrading RF performance is also discussed. Measured phase noise of LC-VCO with proposed CUL structure suggests that a footprint can be effectively reduced without compromising performances. We estimate that PLL size can be reduced by 30% with the proposed technology.

We have developed a pair of sensor head and a prototype data acquisition system for positron emission tomography with a function of time-of-flight measurement. In applying a plastic scintillator suited for timing decision with its fast timing characteristic, we should thus use Compton scattering rather than photoelectric absorption. This paper gives a brief review of the system and describes the development of a plastic fiber array for the better resolution of the gamma-ray interaction position.

Accurate state recognition of traffic lights is important for a safe urban drive of autonomous vehicles. A traffic light with lower luminance than its ambient is difficult to recognize particularly in a distant. This paper proposes a strategy that improves accuracy of signal state recognition of distant traffic lights with low luminance. Digital map is used to get candidate regions of traffic lights on a captured image. Each candidate is cropped and resized to equalize the size of lamp area on the image. On the resized images, brightness channel image is modified by enhancing pixels that have hue value in the range of traffic signal color. Then, high value pixels on the SV m image, which is the muitilpied image of the satulation channel and the modified brightness channel, is regarded as candidates of lamp area. This strategy attempts to emphasize traffic signal lights darker than its ambient. Experiments in real driving data showed the performance of the proposed method.

Laser based displays have gathered much attention, and they are expected to make an alternative huge market for visible laser diodes (LDs), because only the displays may have a wide color gamut which can express ITU-R BT.2020. Single panel spatial light modulator (SLM) type projectors using broad area (BA) LDs for light sources are most popular so far, and multi-panel ones have started to spread especially for high luminosity. The laser light source for the projector consists of red, green and blue color LDs or blue LD + yellow phosphor (+ red LD). Common requests for the LDs are highly-reliable high-power operation at high case temperature.

High output power of 7.6 mW from a blue GaN-based VCSEL was successfully demonstrated under CW operation by reducing both the internal loss and the reflectivity of the front cavity mirror. The internal loss was significantly reduced by introducing the SiO 2 -buried lateral optical confinement configuration.

This paper highlights the importance of utilizing artificial intelligence to safely localize autonomous vehicles in hard weather and environmental conditions. An edge profile is created to encode the lateral road-marks as a series of peaks. A neural network is utilized to explore different relationships between the peaks among a set of map edge profiles. Based on the generalization capability of the trained network, the LIDAR profiles are reconstructed during the autonomous driving to regularly reform the peaks in terms of distribution and amplitude patterns. A reconstructed profile is then matched to the corresponding map profile to estimate the lateral vehicle position accurately. The proposed framework has been tested in very hard situations of snow and grass accumulation at the roadside, snow lines inside lanes and, on wet and old road surfaces. The experimental results have verified the reliability and safety of reconstructing LIDAR profiles to achieve precise lateral localization against the changes of road, weather and environmental conditions.

For the determination of the Avogadro constant via the XRCD-method the ratio of two temperature-dependent quantities, the unit cell volume and the sphere volume, need to be measured with the smallest possible uncertainties. Since both quantities show the same temperature dependency, only the reproducibility of the temperature measurements has to be taken into account. This paper summarizes the test measurements made for determining the accuracy of the temperature measurements of the standard platinum resistance thermometers which are used in the measurements of the silicon-lattice parameter at the INRIM and PTB, and the volume, at the NMIJ and PTB.

To determine the Avogadro constant by the International Avogadro Coordination using the x-ray crystal density method, the volume of a28Si-enriched sphere, named Si28kgOla, was measured at NMIJ. The volume was determined from the diameter measurement in 2175 directions by an optical interferometer. Taking into account the results of the surface characterization of the sphere by x-ray photoelectron spectroscopy and spectroscopic ellipsometry, the volume of the Si core excluding the surface layers was determined with a relative uncertainty of $\pmb{2\ \times\ 10^{-8}}$ . Details of the interferometer and the uncertainty analysis of the volume measurement are presented.

For the determination of the Avogadro constant using the x-ray crystal density method, surface analysis of Si spheres is essential. The difference of the surface layer thickness in vacuum and in air conditions was investigated by ellipsometry. In order to estimate the effect of vapor adsorption on the determination of the thickness of the surface layer of Si spheres, an ellipsometer with vacuum chamber and vapor controlling system is proposed.