Plasma is a useful tool to synthesize carbon nanomaterials, including diamonds, fullerenes, nanotubes, and graphenes. This review gives an overview of these carbon nanomaterials produced by thermal or nonthermal plasmas and of the authors' work related to plasma-enhanced chemical vapor deposition of carbon nanotubes, along with an analysis and numerical simulation of CH₄/H₂ feedstock gas plasmas. The amount of carbon atoms in the grown carbon nanotubes and that calculated by simulation showed good agreement. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(6): 1–8, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11504

Three-dimensional measurement and modeling systems with digital cameras on PCs are now making progress and increasingly felt to be desirable in terrestrial (close-range) photogrammetry for such sectors as cultural heritage preservation, architecture, civil engineering, manufacturing, measurement, etc. Therefore, we have developed a system to improve the accuracy of stereo-matching, which is the very core of 3D measurement. As a stereo-matching method, in order to minimize mismatch and to be robust in geometric distortions, occlusion, as well as brightness change, we invented the Coarse-to-Fine Strategy Method by integrating OCM (orientation code matching) with LSM (least squares matching). This system could attain an accuracy of 0.26 mm in experiments on a mannequin. In real-world experiments on archaeological ruins in Greece and Turkey, the accuracy was within 1 cm, compared with their blueprint plan. Formerly, workers required at least 1.5 months for this kind of survey operation with existing methods, but now only 3 or 4 days is needed. This confirmed the practicality and efficiency of the new method. Herein we demonstrate our new system of 3D measurement and stereo-matching and present some concrete examples of its practical application. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(6): 9–21, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11459

Recently, semiconductor counterfeiting has become an increasingly serious problem. Therefore, techniques to prevent counterfeiting by using random characteristic patterns that are difficult to control artificially have attracted attention. The physical unclonable function (PUF) is one of these techniques. It is a method of deriving ID information peculiar to a device by detecting random physical features that cannot be controlled during the device's manufacture. Because information such as the ID information is difficult to replicate, PUF is used as a technique to prevent counterfeiting. Several studies have been reported on PUF. The arbiter PUF, which utilizes the difference in signal propagation delay between selectors, is a typical method of composing PUF using delay characteristics. This paper proposes a new PUF which is based on the arbiter PUF. The proposed PUF introduces new multiplexing selector units. It attempts to generate an effective response using the orders of three signal arrivals. Experiments using FPGAs verify the validity of the proposed PUF. Although Uniqueness is degraded, Correctness, Steadiness, Randomness, and Resistance to machine learning attacks are improved in comparison with the conventional approach. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(6): 22–31, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11458

CFRP (Carbon Fiber Reinforced Plastic) is widely used in the structures of aircraft, automobiles, wind turbines, and rockets because of its qualities of high mechanical strength, low weight, fatigue resistance, and dimensional stability. However, these structures are often at risk of being struck by lightning. When lightning strikes such structures and lightning current flows through the CFRP, it may be structurally damaged because of the impact of the lightning strike or by ignition between layers. If there are electronic systems near the CFRP, they may break down or malfunction because of the resulting electromagnetic disturbance. In fact, the generation mechanisms of these breakdowns and malfunctions depend on the current distribution in the CFRP. Hence, it is critical to clarify the current distribution in various kinds of CFRPs. In this study, two kinds of CFRP panels, one composed of quasi-isotropic lamination layers and the other composed of 0°/90° lamination layers of unidirectional CFRP prepregs, are used to investigate the dependence of the current distribution on the nature of the lamination layers. The current distribution measurements and simulations for CFRP panels are compared with those for a same-sized aluminum plate. The knowledge of these current distribution characteristics would be very useful for designing the CFRP structures of aircraft, automobiles, wing turbines, rockets, etc. in the future. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(6): 32–40, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11457

Nanocomposite materials based on polyamide-imide have not been able to prevent nano-particles from aggregating, and therefore the development of this material has been extremely difficult. However, we prevented aggregation of nano-particles by developing the low-hygroscopicity solvent and the copolyamide-imide, and commercialized a new partial discharge-resistant enameled wire with nanocomposite polyamide-imide insulating material in 2010. The lifetime of the newly developed partial discharge-resistant nanocomposite polyamide-imide enameled wire is 1000 or more times that of ordinary organic-enameled wire. The lifetime of the new wire is also excellent in a high-temperature atmosphere. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(6): 41–48, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11456

In ultralow-field MRI with an optically pumped atomic magnetometer (OPAM), it is required for the direct detection of MR signals with high sensitivity to match the resonant frequency of potassium to that of protons. A ferrite shield box, which has high permeability and high electric resistance, can be utilized to match the resonant frequencies. In this study, analyses of magnetic field distributions in the vicinities of the sample and the potassium vapor cell of an OPAM were carried out. In addition, the uniformities of the magnetic fields in the areas of the sample and the potassium vapor cell of the OPAM and the magnetic field caused by MR signals were evaluated. These analyses indicated that the resonant frequencies of protons and potassium were matched by using the ferrite shield box with a number of combinations of height and thickness. The uniformities of the magnetic fields applied to a sample were found to be improved by placing the ferrite shield box far from the sample. Furthermore, regardless of the height, the magnetic field caused by the MR signals could be measured. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(6): 49–56, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11455 3

This paper considers cases where a specific number of nodes in an ad hoc network broadcast video and audio streams over the entire network, and proposes Load and Battery Charge Oriented Flooding (LBF), which reduces degradation in delivery quality, lowers energy consumption, and prevents nodes from being interrupted due to the complete discharge of their batteries. It also describes an evaluation of the proposed method through network simulation, and confirms its effectiveness. © 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(6): 57–66, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11567