We have developed a microfracture strength evaluation technique that uses a spherical indenter made from nano-polycrystalline diamond. The technique enables us to evaluate the fracture strength characteristics in the micro regions of diamond materials with a high accuracy, which has been difficult in the past. Through evaluation tests on various types of single crystal diamonds using the technique, it was revealed that the fracture strength of natural diamond greatly differs depending on the location in each crystal, while that of synthetic diamond is uniform with small deviations. We also confirmed that the microfracture strength of nanopolycrystalline diamond is increased through grain refinement.

Vehicle electrification has been proactively promoted because of environmental restrictions. At the same time, new functions, such as autonomous driving and V2X communication, have made vehicle systems more complex. As the development costs have risen following these trends, system development using simulation has come into widespread use to improve cost efficiency. We have been developing simulation techniques to identify the effects of improvements in our product performance in regard to power consumption. This paper introduces a simulation technique to verify the trade-off between power consumption and ride comfort.

In a visual inspection setting, quantitative and qualitative judgment is needed. To automate this particular judgment process, an algorithm that resembles human recognition ability is required. Sense Learning is our algorithm that mimics the human recognition ability using the images of non-defective products. With an autoencoder, a deep-learning-based network, the inspection AI progressively learns to reconstruct the images of non-defective products, thereby acknowledging the ideal characteristics of products. When the image of a defective product is input, the inspection AI fails to reconstruct the defective part because it has never learned the form. Based on the difference between the input image and the reconstructed image, Sense Learning detects the defective part and measures the degree of its severity.

Level 3 or higher autonomous vehicles, which themselves control all aspects of driving, require lane-specific traffic information for safe and smooth driving. While this information is expected to be generated using probe data sent from vehicles, there are still problems such as the insufficient positioning accuracy of probe data for identifying the driving lane and the low penetration rate of probe vehicles. To overcome these problems, we have developed a system for generating lane-specific traffic information. The system uses images sent from on-vehicle front view cameras, which are in widespread use today, to identify the driving lane and the propagation model of traffic congestion to supplement the probe data.

For further automation and efficiency improvement of production, industrial control systems have been increasingly connected to other information systems to exchange data. Under this circumstance, establishing security measures for control systems against malware (such as Stuxnet*1) is an urgent issue. Therefore, security design has been taken into consideration at the beginning of the system development. In collaboration with the National Institute of Advanced Industrial Science and Technology (AIST), we have been applying security design guidelines for automobiles to control systems, aiming to improve the efficiency of design procedures without depending on personal knowledge or experience. Focusing on the risk-assessment phase in security design consisting of multiple phases, this paper proposes a quantification method optimized for the risk assessment of control devices and systems by utilizing an existing vulnerability assessment system. We report on the security design results using the method, providing a case study on a control system equipped with a data logger as the key element.

Physical contact (PC) optical connectors are commonly used for their favorable connection characteristics. However, PC connectors have some drawbacks such as the necessity of careful end face cleaning and an increasing mating force as the number of fibers increases. To overcome these drawbacks, we have developed a new multi-fiber connector that has an air-gap between its end faces. Eliminating the need for PC connection, this connector offers good optical characteristics and high reliability. This paper reports on the optical characteristics and reliability test result of the new connector.

With the growth of cloud services that require high-speed communication, CFP4 and QSFP28 optical transceivers have been commonly used for 100 Gbit/s transmission. Along with an increase in the market need for higher-speed transmission beyond 100 Gbit/s, the Institute of Electrical and Electronics Engineers (IEEE) published 400GBASE-FR8/LR8 as the next-generation communication standards, and the CFP Multi-Source Agreement (MSA) defined the CFP8 form factor of an optical transceiver to support 400 Gbit/s interfaces. Against this backdrop, we have developed a new optical receiver module for 400GBASE-FR8/LR8 CFP8. Using the conventional design for 100 Gbit/s, the module has an integrated 8-ch optical de-multiplexer. This paper describes the module structure, optical characteristics, and sensitivity in 26.56 Gbaud PAM4 signal transmission.

The demand for high-speed data communication systems has been increasing to accommodate huge data communication traffic resulting from the growth of smartphone and cloud computing services via data centers. This trend has generated a strong demand for high-speed optical transceivers. To transmit electric signals without distortion, transmission lines are designed with a due consideration of characteristic impedance. Nevertheless, electric signals tend to be distorted by unexpected factors on actual circuit boards. These factors often consist of signal integrity, power integrity, and electro-magnetic interference/electro-magnetic susceptibility, which are correlative to each other. For these problems, electromagnetic field analysis plays an extremely important role. This paper describes typical contributing factors, as well as problem examples and their solutions extracted by electromagnetic field analysis.

We have developed a 40-W microwave integrated circuit (MIC) equipped with gallium nitride (GaN) high electron mobility transistors (HEMTs) that is functional in the L-band and S-band for satellite and rocket launch control applications. The MIC has a 10-W GaN HEMT in the front stage and a 40-W GaN HEMT in the post stage. It achieves an output of over 45 W, gain of over 30 dB, and power added efficiency (PAE) of 45% in the range of 1.0-1.7 GHz, while it shows an output of over 47 W, gain of over 30 dB, and PAE of 50% in the range of 2.0-2.7 GHz. The GaN HEMTs met all the reliability and lifetime requirements in a space qualification test. When used in a solid state power amplifier, the MIC will contribute to a reduction in the size and weight of satellites.

As a solution to the rapidly increasing optical traffic, 100 Gbit/s transmission systems using the digital coherent optical communication technology has been adopted in high-speed and large-capacity optical transmission. Optical transceivers are required to be operable in the long wavelength band (L-band) in addition to the conventional band (C-band). Based on the design of C-band receivers, we have developed compact optical receivers for the L-band operation. This paper presents the design and typical characteristics of the new optical receivers.

Power devices have been essential to significantly advance efficient electric power use mainly for a future electric network society that will use versatile energy sources such as renewable energy resources and electric vehicles. SiC power devices are expected to be a key for power conversion systems to cut back electric power loss. To achieve large chip dies used in high current ratings, the wafer size of SiC substrates has increased, requiring precisely controlled fabrication processes. The epitaxial layer used for the drift region in a device structure strongly influences the device performance, entailing to the requirement of epitaxial defects reduction as well as the precise control of doping concentration and thickness for stable chip production. We have successfully demonstrated an extensive defect-free epitaxial layer with an excellent doping concentration and thickness uniformity on a 150 mm diameter 4H-SiC substrate.

Due to the development and wide-spread use of high-voltage direct current (HVDC) transmission and its related equipment, the evaluation of the dielectric properties of insulation materials under HVDC has become important. While the evaluation of electric properties is generally carried out using different methods appropriate for their specific purposes, the authors have found a relatively simple technique that can simultaneously evaluate multiple dielectric properties of a material, such as permittivity, space charge behavior, and electrical conductivity, using the direct current integrated charge method. This paper describes the principle of the method and measurement results of low- and high-density polyethylene and polystyrene.

With an increase in the use of renewable energy, the problem of power system constraints in which electricity transmission is limited has become significant. One major factor of this is the restricted capacity of transmission lines. While the enhancement of the transmission line capacity is necessary to solve this problem, it requires a large amount of capital and time. Therefore, it is important to utilize existing systems to their maximum potential. For the purpose of increasing power transmission capacity of existing systems, we have been developing a real-time monitoring system for the temperature and electric current value of power transmission lines. This paper reports on the present status of our ongoing developments.

Due to technological innovation utilizing information technology (the fourth industrial revolution), major changes are taking place at manufacturing sites. Internet of Things (IoT) technology is expected to improve production capacity and efficiency through the collection and analysis of a large amount of data by networking many sensors and devices. In the automobile industry, the development of common platforms and modules has been progressing, requiring parts manufacturers to cope with demands for cost reduction in super-mass production and quality risk management to prevent mega recall. To adapt to the age of megaplatforms, we have built an innovative sintered part production line making full use of IoT technology. Based on the Sumitomo Electric Group’s manufacturing concept, Sumitomo Electric Industries Production System (SEIPS), the new production line features: (1) zoned quality control by automated inspections, (2) quality assurance in units of products using 2D codes, (3) reduction of lead time and no intermediate stock by “one-by-one production / synchronized production” through compacting, sintering, sizing, to machining, and (4) IT-based production-management and monitoring systems.

Sumitomo Electric System Solutions Co., Ltd. Develops and sells AgentNavi, a navigation software development kit for smartphones. AgentNavi offers route guidance to the destination together with information about traffic congestion and regulations.