Nagoya Institute of Technology

About: Nagoya Institute of Technology is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Thin film & Catalysis. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

Text-to-visual speech synthesis based on parameter generation from HMM

Abstract: This paper presents a new technique for synthesizing visual speech from arbitrarily given text. The technique is based on an algorithm for parameter generation from HMM with dynamic features, which has been successfully applied to text-to-speech synthesis. In the training phase, syllable HMMs are trained with visual speech parameter sequences that represent lip movements. In the synthesis phase, a sentence HMM is constructed by concatenating syllable HMMs corresponding to the phonetic transcription for the input text. Then an optimum visual speech parameter sequence is generated from the sentence HMM in an ML sense. The proposed technique can generate synchronized lip movements with speech in a unified framework. Furthermore, coarticulation is implicitly incorporated into the generated mouth shapes. As a result, synthetic lip motion becomes smooth and realistic.

Sensorless Torsion Control of Elastic-Joint Robots With Hysteresis and Friction

Abstract: Sensorless torsion control is proposed for elastic-joint robots, with the geared drives subject to hysteresis and friction nonlinearities. The concept of the so-called “virtual torsion sensor” uses the motor torque and velocity, inherently available in most industrial robots, for estimating the reactive joint torque and predicting, based thereupon, the nonlinear joint torsion. The dynamics of the elastic-joint robot is described and augmented by a rate-independent torsion–torque hysteresis and nonlinear friction assumed on the side of motor drives. The classical two-degrees-of-freedom robot control, which includes the centralized torque feedforward control and proportional-derivative feedback control, is extended by the virtual torsion sensor in the loop. In particular, we show that the computed joint torsion can be injected in the feedback loop upon the motor position, thus making the control operating in a “virtual” joint output (link) space. The proposed control is experimentally evaluated on a single-joint setup consisting of an actuator with harmonic-drive gear and inertial load under additional impact of gravity.

Effect of wall surface reaction on a methane-air premixed flame in narrow channels with different wall materials

Abstract: In order to elucidate effect of wall material on chemical quenching behavior, a methane-air premixed flame formed in 5-mm-wide channel is investigated. In the present study, platinum, quartz, alumina and chromium are chosen as the wall materials. Platinum, chromium and alumina thin films ∼100 nm in thickness are deposited on quartz substrates using sputtering, vacuum arc plasma gun or atomic layer deposition techniques to establish equivalent thermal boundary condition with different wall chemical reactions. OH-PLIF/micro-OH-PLIF and numerical simulation with detailed reaction mechanisms are employed to examine interaction between the gas-phase and the wall surface reactions. It is clearly shown through the PLIF measurements that OH ∗ mole fraction in the vicinity of the wall is the highest for alumina, while it is decreased in order of quartz, chromium, and platinum. On the platinum surface, the gas-phase combustion is suppressed due to fast consumption of the reactants by the catalytic reaction. On the other hand, on the other surfaces, radical quenching cause the reduction of OH ∗ near the wall. By using a radical quenching model, the initial sticking coefficient associated with radical adsorption is evaluated. It is found that radical quenching does exist on the quartz wall, while the alumina surface works as an inert surface.