Masanari Taniguchi

Characterization of road traffic flow from measured data of speed and time-headway -relationship between density ( k ), flow rate ( q ) and speed (V )-

Basing upon the newly defined parameters of vehicle density on road (k ) and flow rate (q), the traffic flow was analyzed from video images taken at urban, suburban and expressway. The measured data are time-headway (T) and speed (V). Both T and V are measured using the unit of second (s) and meter par second (m/s), respectively. The data were collected manually by using stopwatch. The parameter k was defined from T and V , then it became a non-dimensional parameter as a normalized one that was confined between 0 and 1 (0 < k < 1). The data of about 1000 vehicles were obtained. The relationship between k and V (k -V characteristics) was examined, which obeys the exponential function with good accuracy.

Precise Measurement of Dark Bridge between Micro-gap Electrical Contacts in a State of Thermal Equilibrium Condition

Newly discovered nonluminous (dark) bridge was precisely produced and measured its size by microscopic means. Palladium (Pd) was tested as a typical contact material. The contacts separating system was constructed by using 1 (m) long steel cantilever system. The experiments were carried out with very slow opening speed and observed the bridge growing process with the microscope. The contacts were set at the bottom side of the cantilever and controlled its moving speed (contacts separating speed) by pushing the top of the cantilever, that can reduce the displacement scale with any reduction ratio but we chose it by one-thirtieth (1/30) and we reached the separation speed of 0.05 mum/s that was enough to maintain the thermal equilibrium condition. Both the bridge voltage and the displacement of electrode were monitored and recorded. The microscopic images of the bridge were stored in the computer, from which the size of the bridge was measured for each image and plotted on a graph showing the relationship between bridge length and diameter. The results showed that enough correspond to the theoretical estimation formerly presented by the authors

Thermal Analysis of Printed Circuit Board Due to Thermal Stress By Using Thermography and Holography

By using both FEMLAB simulator and the Thermography, the thermal pattern was analyzed of printed circuit board deformed due to thermal stress. And, the deformation pattern was measured by using the holographic pattern measuring system (HPMS). As the results, both thermal pattern and deformation pattern were observed as a different pattern each other. And, we found that the HPMS could be effectively used as a tool for analyzing PCB deformation with 3-D graphic image

Observation of contact bridge phenomena at transient and steady state

Two systems have been developed for precise observation of both transient and steady state of contact bridge phenomena. The one is the system, which can separate contacts with 0.5 micrometer steps, and another is that can more precisely separate the contacts and hold the contact gap constant at any gap length. The observed bridge voltage waveforms using the former system have been presented and shown the voltage waveforms at an instant of contacts separation as both the transient and semi-steady state phenomena. A part of the observed results using the latter system has also been presented and shown the precise bridge voltage waveforms as well as its cylindrical shape, which have shown us some interesting and new phenomena. The above mentioned two cases of observed results are shown in This work.

Application of holographic interferometry measuring technique to deformation measurement of bone due to thermal stress

The holographic interferometry measuring system (HIMS) was applied to the deformation measurement of the bone which is deformed due to thermal stress. A thermo-graphic measuring system (TGMS) was also applied to show a correlation between the holographic deformation pattern and thermal pattern on the bone surface. From the experimental results, the same thermal pattern was observed for different experimental conditions, however, the different holographic pattern that correspond to the deformation was observed for each experimental condition. From this result, we found that the HIMS could be effectively used as a measuring tool for the bone deformation.

Application of digital still camera to improve the extracting process of holographic vibration fringe pattern from interferogram

As is well known, for vibration analysis of an object surface, holographic interferometry is one of the most efficient methods for noncontact measurement of microscopic displacement. For this purpose, the authors have developed a holographic pattern measuring system (HPMS) which can draw a 3D graphic image pattern of a vibrating surface. However, in the present HPMS, the fringe pattern data must be obtained manually with a digitizer, which consumes much time and is inefficient. In this study, to resolve this problem in the HPMS, the authors introduced a digital still camera to perform extraction accurately and improve the fringe pattern extraction process from the holographic interferograms.

Application of Holography to evaluation of printed circuit board connector due to thermal stress

Printed circuit board connectors (PCB connectors) were tested by using the HPMS (Holographic Pattern Measuring System) , that has been developed by the authors to estimate the surface deformation due to thermal stress. The system was well performed to investigate the PCB connector contact failure process as a model investigation. The analysis was only on a stage of qualitative, however, some important suggestions were obtained for the future usage and selection of not only PCB connector itself but also selection of socket pin for power supply in the selected connector.

3-D Graphic Image of Vibration Pattern of Printed Circuit Board by Using Holography

The authors have developed a holographic patten measuring system (HPMS) for quantitative measurement of microscopic displacement and mechanical vibration with high precision. In this study, by using the holographic interferometry technique, the microscopic displacement of PCB surface was measured with fringe pattern in case of vibration and shock that were imposed by the operation of mounted electromagnetic relay, and some different vibration patterns were observed corresponding to fixing condition of the Printed Circuit Board. In addition, a graphic image processing technique was applied and the displacement level could be quantitatively measured with an accuracy of about 0.1 mum, and could be evaluated by the 3-D graphic image pattern.

An experimental study on the relationships between the speckle noise and the deformation of optical fiber

In order to apply a speckle noise in optical fiber to sensor, the relationship between speckle noise pattern and deformation of the optical fiber was investigated. In the experiment. the He-Ne gas laser as light source, and the multi-mode and graded index optical fiber (quartz) were used. The image through the optical fiber was observed with respect to the movement of optical axis and the distortion of optical fiber. In addition. in order to extract the speckle noise pattern from the optical image, the digital image measuring system was applied. And, for both quantitative extraction and characterization of the speckle noise pattern variation, the digital logic operating technique was applied.