All issues
Volume 52, Issue 10
Displaying 1-9 of 9 articles from this issue
- |<
- <
- 1
- >
- >|
Special Issue on the New Tide of Sensing Technology
-
Toshiyuki TANAKA, Hidekata HONTANI, Yusuke KAWAKITA, Hiroshi SATO, Tos ...2016 Volume 52 Issue 10 Pages 517
Published: 2016
Released on J-STAGE: October 25, 2016
JOURNAL FREE ACCESSDownload PDF (183K)
Paper
-
Takayuki HOSHI, Shigeru HAYATA2016 Volume 52 Issue 10 Pages 518-523
Published: 2016
Released on J-STAGE: October 25, 2016
JOURNAL FREE ACCESSBonding machines suffer from a problem that a wavering disturbance of air occurs due to heaters and decreases the accuracy of vision sensing for tool positioning. Previous solutions use airflow to clear out heated air from the light path or physical/airflow walls to separate heated air from background air. Although these previous solutions have been in practical use, they have some drawbacks. Airflows reduce the bondability on the chip surface and have negative effects on the generation of FAB (free air ball) at the tip of wires. Physical walls convey heat to cameras and cause their thermal expansion, and the structure of the physical walls may vibrate due to the rapid motion of the other machine components. In order to avoid these drawbacks, we propose a new method that keeps the light path calm using ultrasonic standing wave. The incident ultrasonic wave travels vertical to the light path, and is reflected by a reflection wall. These incident and reflected ultrasonic waves make a standing wave which has a periodic structure of nodes and antinodes. The fluctuation of air is suppressed in this stable structure. To evaluate the performance of the proposed method, experiments were conducted. We took two parameters in the experiments. One was the distance between the light path (observation point) and the reflection wall. The other was the ultrasonic output. The experimental results showed that an antinode of sound pressure of the ultrasonic standing wave was the best part to suppress the fluctuation of the air and moderate ultrasound output was more effective.View full abstractDownload PDF (1113K) -
Masaya TAKE, Hiroyuki KOMORI, Nozomi SHIGEMATSU, Yuji GOTOH2016 Volume 52 Issue 10 Pages 524-530
Published: 2016
Released on J-STAGE: October 25, 2016
JOURNAL FREE ACCESSThe development of the inspection technique of detecting the slack of the high tension bolt used in an elevated bridge, a railway viaduct, and various mechanical parts, etc. is desired. The permeability inside the side of the bolt head is changed since the bolt head is compressed by bolting a plate. Therefore, the evaluation of the slack of the bolt is possible by detecting the difference of the magnetic characteristics. In this paper, the electromagnetic inspection method for measuring the slack of the steel high-tension bolt of hexagon head using the small alternating magnetic field probe sensor is proposed. The stress and flux density near the bolt head are estimated by 3-D nonlinear electromagnetic finite element method (FEM) analysis taking account of the electromagnetic property under various compressive stresses. The results showed that the non-destructive inspection of the slack of the high-tension bolts is possible by detecting the change of flux density in the proposed small inspection probe sensor.View full abstractDownload PDF (2557K) -
Toshiro NAKASHIMA, Osamu MATOBA2016 Volume 52 Issue 10 Pages 531-537
Published: 2016
Released on J-STAGE: October 25, 2016
JOURNAL FREE ACCESSWe have developed a detection method of the state of water using near-infrared light-absorption. In this paper, a new evaluation index of the frozen state of water is proposed. In this case, we focused on the light-absorption characteristics of water. The experimental results showed that the absorption peak shifts to longer wavelength when the water state changes into ice state. To remove the affect of the scattering by bubbles generated in the freezing process and the thickness of the water layer, we have proposed a new evaluation index based on absorbed light intensity ratio at two wavelengths. The index is constant even when the layer thickness changes from 1mm to 3mm and is not also affected by light scattering. This result indicates that the proposed evaluation index can be used as a criterion to detect the liquid phase (water state) or the solid phase (ice state). It has been confirmed that the method using the index is effective for monitoring the water freezing process with supercooling by the experiment.View full abstractDownload PDF (1187K) -
Takashi MIWA2016 Volume 52 Issue 10 Pages 538-544
Published: 2016
Released on J-STAGE: October 25, 2016
JOURNAL FREE ACCESSIn imaging of reflection coefficient of targets using a coherent wave, we propose a novel inverse synthetic aperture radar imaging method to obtain cross-range resolution without antenna scan or array antennas. In this method a forced vibration wave is induced outside the region of interest to vibrate the target. Sweeping the vibration frequency, a complex Doppler signal generated by the vibrated target is measured. By the Fourier transformation of the vibro-Doppler signal measured in each swept frequency, spatial reflection profile is obtained without scanning transmitter and receiver. In this paper, we show an algorithm of this method and demonstrate the validity of this method through measurements using an ultrasonic wave.View full abstractDownload PDF (1308K)
Paper
-
Takeshi UCHITANE, Nobuyasu ITO2016 Volume 52 Issue 10 Pages 545-554
Published: 2016
Released on J-STAGE: October 25, 2016
JOURNAL FREE ACCESSIn this paper, we apply a factor analysis which is a kind of multivariate statistics to the results of vehicle traffic simulation of Kobe-city, Japan. City scale traffic simulations usually output multivariate results. However, both in the context of data assimilation and in the context of statistical hypothesis testing, such results are often treated as independent variables. Lack of concerning such result correlations results in worse accuracy of the simulation result. Therefore, better statistical comparisons and better statistical analyses between simulation results are strongly required. From the results of factor analysis, it showed that the large number of simulation results were described by 33 factors. Obtained factors which had higher contribution rate were robust against the time and space of origin and destination and against the number of vehicles. Moreover, the higher contribution rate factors can be distinguished from other factors which can be obtained even if simulation settings were completely random. Though existences of such factors are out of range of this study, the knowledge of factor analysis results may help us not only explain the city traffic simply but also improve accuracy of large scale vehicle traffic simulations.View full abstractDownload PDF (7020K) -
Kunpei YAMADA, Hiroshi DEGUCHI2016 Volume 52 Issue 10 Pages 555-565
Published: 2016
Released on J-STAGE: October 25, 2016
JOURNAL FREE ACCESSEstimating future population is important process of policy making in managing social infrastructure or urban development, especially in Japan with a declining population. In this research, I described and illustrated the merits of Agent Based Simulation (ABS) method for estimating population and proposed applying the Move-Model to local policy evaluation. The model is based on household's autonomous decision making to move. As a result, this work enabled extensive analysis on how population dynamics will be changed by execution of policy plan.View full abstractDownload PDF (1712K) -
Kei SENDA, Koyu AMANO2016 Volume 52 Issue 10 Pages 566-572
Published: 2016
Released on J-STAGE: October 25, 2016
JOURNAL FREE ACCESSModel-based reinforcement learning includes two steps, estimation of a plant and planning. Planning is formulated as dynamic programming (DP) problem, which is solved by a DP method. This DP problem has an equivalent linear programming (LP) problem that can be solved by LP method, but it is generally less efficient than typical DP method. However, numerical examples show linear programming is more efficient than the typical DP method in problems whose self-transition probabilities are large. The reason is clarified by geometrical discussion of each solution of method approaches to optimal solution.View full abstractDownload PDF (685K) -
Hidekazu KAJIWARA, Naohiko HANAJIMA, Manabu AOYAGI2016 Volume 52 Issue 10 Pages 573-579
Published: 2016
Released on J-STAGE: October 25, 2016
JOURNAL FREE ACCESSWhen periodic external force is inputted to van der Pol equation, its self-excitation vibration is suppressed, and its oscillatory frequency synchronizes with frequency of the external force. This behavior is called forced entrainment. We proposed periodic input control method that can control energy of system using forced entrainment, and controlled periodic motion of various systems (such as pendulum, quasi passive walking robot and hopping robot). Because a periodic input control system whose energy is controlled by our method, vibrates without external force continuously, it is supposed that the system is a self-excitation vibration system. Therefore, we analyzed structure and characteristics of the system. First, we analyze whether periodic input system has characteristics as self-excitation vibration system. Next, we derive the condition that forced entrainment is caused by periodic external force. Finally, we show the result that inspected validity of our analysis by experiments.View full abstractDownload PDF (1294K)
- |<
- <
- 1
- >
- >|