System for augmented human–robot interaction through mixed reality and robot training by non-experts in customer service environments

Human–robot interaction during general service tasks in home or retail environment has been proven challenging, partly because (1) robots lack high-level context-based cognition and (2) humans cannot intuit the perception state of robots as they can for other humans. To solve these two problems, we present a complete robot system that has been given the highest evaluation score at the Customer Interaction Task of the Future Convenience Store Challenge at the World Robot Summit 2018, which implements several key technologies: (1) a hierarchical spatial concepts formation for general robot task planning and (2) a mixed reality interface to enable users to intuitively visualize the current state of the robot perception and naturally interact with it. The results obtained during the competition indicate that the proposed system allows both non-expert operators and end users to achieve human–robot interactions in customer service environments. Furthermore, we describe a detailed scenario including employee operation and customer interaction which serves as a set of requirements for service robots and a road map for development. The system integration and task scenario described in this paper should be helpful for groups facing customer interaction challenges and looking for a successfully deployed base to build on.     

Fast chemical vapor deposition of microcrystalline silicon by applying magnetic field to hollow electrode enhanced radio frequency glow plasma

Fast chemical vapor deposition of microcrystalline silicon by applying magnetic field to hollow electrode enhanced radio frequency (rf) glow plasma has been investigated. We have already developed a plasma generation technique called hollow electrode enhanced rf glow plasma transportation (HEEPT). In this study, we equipped a HEEPT system with a hollow cylinder shaped permanent magnet around an orifice prepared at the center of the counter electrode. The plasma was characterized by plasma emission spectroscopy. Silicon thin films were deposited on a glass substrate. It was found that increasing the magnetic flux density resulted in increasing plasma emission intensity, film deposition rate, and crystallinity. The maximum deposition rate of 6.9 nm/s was achieved with high crystallinity and photo-sensitivity at a plasma excitation frequency of 13.56 MHz, a substrate temperature of 300 °C and a magnetic flux density of 75 mT. Our results indicate that the magnetic field is effective in promoting fast chemical vapor deposition of microcrystalline silicon thin films with photo-sensitivity using the HEEPT technique. We consider that the effectiveness is due to a decrease of electron temperature caused by drift motion of electrons in the magnetic field inside the orifice.     

Effect of W-Mo balance and boron nitrides on creep rupture ductility of 9Cr steel

The effect of W-Mo balance and boron nitrides (BN) on creep rupture ductility has been investigated for five heats of 9% Cr steel with 1.5% Mo equivalent, 0.003% boron and 0.05% nitrogen at 600^oC, 650^oC and 700^oC. The maximum time to rupture was 68,718 h at 650^oC. The reduction of area (RA) slightly decreases for up to about 8000 and 1000 h at 600 and 650^oC, respectively, while it significantly decreases above those. The BN particles are responsible for the degradation in RA at low stresses and long times by accelerating the formation of creep voids. At high stresses and short times, the RA decreases with increasing time to rupture and with increasing W concentration and concomitantly with decreasing Mo concentration. The rupture ductility is evaluated by using a semi-logarithmic diagram of the RA and total elongation, showing the necking dominant and void swelling dominant regions.     

Robust stability analysis with cycling-based LPTV scaling. Part II: its properties under the use of FIR separators

This paper is concerned with robust stability analysis of discrete-time linear periodically time-varying (LPTV) systems using the cycling-based LPTV scaling approach. It consists of applying the separator-type robust stability theorem through the cycling-based treatment of such systems, where this paper aims at revealing fundamental properties of this approach when we confine ourselves to what we call finite impulse response (FIR) separators as a theoretically and numerically very tractable class of separators. Specifically, we clarify such properties of the cycling-based LPTV scaling approach using FIR separators that cannot readily be seen under the treatment of general class of separators. This is accomplished by comparing it with another approach, called lifting-based LPTV scaling using FIR separators, through the framework of representing the associated robust stability conditions with infinite matrices. More precisely, this leads us to clarifying the fundamental relationships between the cycling-based and lifting-based approaches under the use of FIR separators. We also provide a numerical example demonstrating the fundamental relationships clarified in this paper.     

X-Ray diffraction analysis of multilayer InAs-GaAs heterostructures with InAs quantum dots

Multilayer InAs-GaAs structures with an array of vertically aligned InAs quantum dots in a GaAs matrix, grown by molecular-beam epitaxy, were investigated by crystal truncation rods and high-resolution x-ray diffractometry methods. It was shown that the formation of scattering objects such as vertically aligned quantum dots in the structures strongly influences the mechanism of diffraction scattering of x-rays and changes the spatial distribution of the diffracted radiation. This is explained by the appearance of additional long-range order in the lateral arrangement of the scattering objects in the periodic structures, by the curving of the crystallographic planes in the periodic part of the structure, and by the quasiperiodicity of the deformation profile due to the vertically coupled quantum dots. The observed spatial distribution of the diffracted intensity can be explained qualitatively on the basis of a new model where the scattering layers with quantum dots consist of defect-free, coherently coupled, InAs and GaAs clusters. Fiz. Tekh. Poluprovodn. 33, 1359–1368 (November 1999)     

Suppression of Bone Necrosis around Tooth Extraction Socket in a MRONJ-like Mouse Model by E-rhBMP-2 Containing Artificial Bone Graft Administration

Medication-related osteonecrosis of the jaw (MRONJ) is related to impaired bone healing conditions in the maxillomandibular bone region as a complication of bisphosphonate intake. Although there are several hypotheses for the onset of MRONJ symptoms, one of the possible causes is the inhibition of bone turnover and blood supply leading to bone necrosis. The optimal treatment strategy for MRONJ has not been established either. BMP-2, a member of the TGF-β superfamily, is well known for regulating bone remodeling and homeostasis prenatally and postnatally. Therefore, the objectives of this study were to evaluate whether cyclophosphamide/zoledronate (CY/ZA) induces necrosis of the bone surrounding the tooth extraction socket, and to examine the therapeutic potential of BMP-2 in combination with the hard osteoinductive biomaterial, β-tricalcium phosphate (β-TCP), in the prevention and treatment of alveolar bone loss around the tooth extraction socket in MRONJ-like mice models. First, CY/ZA was intraperitoneally administered for three weeks, and alveolar bone necrosis was evaluated before and after tooth extraction. Next, the effect of BMP-2/β-TCP was investigated in both MRONJ-like prevention and treatment models. In the prevention model, CY/ZA was continuously administered for four weeks after BMP-2/β-TCP transplantation. In the treatment model, CY/ZA administration was suspended after transplantation of BMP-2/β-TCP. The results showed that CY/ZA induced a significant decrease in the number of empty lacunae, a sign of bone necrosis, in the alveolar bone around the tooth extraction socket after tooth extraction. Histological analysis showed a significant decrease in the necrotic alveolar bone around tooth extraction sockets in the BMP-2/β-TCP transplantation group compared to the non-transplanted control group in both MRONJ-like prevention and treatment models. However, bone mineral density, determined by micro-CT analysis, was significantly higher in the BMP-2/β-TCP transplanted group than in the control group in the prevention model only. These results clarified that alveolar bone necrosis around tooth extraction sockets can be induced after surgical intervention under CY/ZA administration. In addition, transplantation of BMP-2/β-TCP reduced the necrotic alveolar bone around the tooth extraction socket. Therefore, a combination of BMP-2/β-TCP could be an alternative approach for both prevention and treatment of MRONJ-like symptoms.     

Purification and characterization of enzyme responsible for N-myristoylation of octapeptide in aqueous solution without ATP and coenzyme a from Pseudomonas aeruginosa

The enzyme that catalyzes N-acyl linkage between myristic acid and the NH(2)-terminal glycine residue of the octapeptide Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg-NH(2) in aqueous solution without ATP and coenzyme A was found in Pseudomonas aeruginosa. The enzyme was purified from cell-free crude extract using DEAE-Cellulose, Sephadex G-200, CM-Sephadex C-50, and hydroxyapatite column chromatographies, and then purified approximately 1900-fold with about 1.5% recovery of enzyme activity from the crude extract. Finally, the purified enzyme showed a main band on SDS polyacrylamide gel electrophoresis after staining with Coomassie Brilliant Blue. The band corresponded to a molecular mass of approximately 60 kDa. The K(m)s of the purified enzyme for the substrate myristic acid and the octapeptide were 0.36 and 2.6 mM, respectively. When myristoyl-CoA instead of myristic acid was used as the substrate for the enzyme reaction, myristoyl octapeptide could be synthesized as observed in the case of myristic acid. The K(m) of myristoyl-CoA was 0.17 mM.     

Analysis of essential amino acid residues for catalytic activity of glutaminase from Micrococcus luteus K-3

Structural-based mutational analysis of salt-tolerant glutaminase from Micrococcus luteus K-3 (Micrococcus glutaminase) revealed that three amino acid residues, S64, K67, and E160, were essential to a catalytic reaction. The result suggested that Micrococcus glutaminase had a possible catalytic mechanism similar to class A beta-lactamase rather than glutaminase-asparaginase from Pseudomonas 7A.     

Analysis of the microstructure near the crack tip of ASME Gr.92 steel after creep crack growth

The microstructures near to and remote from the tip of a crack in ASME Gr.92 steel were investigated after creep crack growth at 873 and 898 K, focusing on the martensitic lath, the dislocation structure, and precipitates. After creep, the mean lath width near the crack tip was obviously larger than that of the virgin material, whereas the lath width remote from the crack tip was only slightly larger than that of the virgin material. The mean dislocation density near the crack tip markedly decreased after creep, whereas only a small change was observed in the dislocation density remote from the crack tip. The mean size of M₂₃C₆ particles near the crack tip after creep was larger than that of the virgin material, whereas their mean size remote from the crack tip was almost the same as that of the virgin material.     

Fe content effects on electrochemical properties of Fe-substituted Li2MnO3 positive electrode material

Fe-substituted Li₂MnO₃ including a monoclinic layered rock-salt structure (C2/m), (Li_1+x(Fe_yMn_1−y)_1−xO₂, 0 < x < 1/3, 0.1 ≤ y ≤ 0.5) was prepared by coprecipitation-hydrothermal-calcination method. The sample was assigned as two-phase composite structure consisting of the cubic rock-salt () and monoclinic ones at high Fe content above 30% (y ≥ 0.3), while the sample was assigned as a monoclinic phase (C2/m) at low Fe content less than 20%. In the monoclinic Li₂MnO₃-type structure, the Fe ion tends to substitute a Li (2b) site, which corresponds to a center position of Mn⁴⁺ hexagonal network in Mn-Li layer. The electrochemical properties including discharge characteristics under high current density (<3600 mA g⁻¹ at 30 °C) and low temperature (<−20 °C at 40 mA g⁻¹) were severely affected by chemical composition (Fe content and Li/(Fe + Mn) ratio), crystal structure (monoclinic phase content) and powder property (specific surface area). Under the optimized Fe content (0.2 < y < 0.4), the Li/sample cells showed high initial discharge capacity (240-300 mAh g⁻¹) and energy density (700-950 mWh g⁻¹) between 1.5 and 4.8 V under moderate current density, 40 mA g⁻¹ at 30 °C. Results suggest that Fe-substituted Li₂MnO₃ would be a non-excludable 3 V positive electrode material.