Journal of Technology and Social Science (JTSS, J. Tech. Soc. Sci.)
An international open-access peer-reviewed journal
TABLE OF CONTENTS
Linear Vibration Analysis of a Thin Shell-panel Including Clamped Edges
Shinichi Maruyama, Daisuke Kumagai, Takao Yamaguchi and Ken-ichi Nagai
Journal of Technology and Social Science, Vol.4, No.1, pp.1-5, 2020.
Abstract: In this paper, a new analytical method on natural frequencies and vibration modes of a thin shell-panel with clamped edge is presented. At the boundaries of two opposite edges, the shell panel is simply supported, and at the other two edges the panel is simply supported or clamped. Coordinate function of deflection is assumed with the product of power series and trigonometric function. Neglecting the effect of in-plane inertia force, the Donnell type equations are applied as the governing equation of the shell-panel. Stress function is obtained which satisfies exactly the compatibility equation with the inhomogeneous term due to the coupling with deflection and the in-plane boundary conditions. Applying Galerkin method to the equation of motion, natural frequencies and vibration modes are calculated and compared with the exact results.
Propagation of Stress Waves in Viscoelastic Rods and Plates (3) -Acoustic Impedance of a Viscoelastic Rod : the Applicability to the Inverse Calculations -
Ryuzo Horiguchi and Takao Yamaguchi
Journal of Technology and Social Science, Vol.4, No.1, pp.6-21, 2020.
Abstract: We had derived the explicit analytical expression of the complex wave number of a longitudinal wave in a viscoelastic rod and a flexural wave in a viscoelastic beam. In this study, we deal with the longitudinal waves in viscoelastic rods such as cork. This paper focuses on the inverse analysis method to identify the viscoelasticity of a specimen using the acoustic impedance of a viscoelastic rod obtained from the experiment. This method consists of inverse calculations for each step of the physical model. With our simple inverse formulas, it is possible to obtain the complex wave number from the characteristic impedance. It is also possible to identify viscoelasticity from the complex wave number. Furthermore, we developed an inverse calculation method to identify the characteristic impedance of the specimen from the acoustic impedance after the specimen. We confirmed that the conditions of direct analysis are reproduced by inverse analysis.
Digital-to-Analog Converter Layout Technique and Unit Cell Sorting Algorithm for Linearity Improvement Based on Magic Square
Masashi Higashino, Shaiful Nizam Bin Mohyar, Yao Dan, Yifei Sun, Anna Kuwana and Haruo Kobayashi
Journal of Technology and Social Science, Vol.4, No.1, pp.22-35, 2020.
Abstract: This paper describes techniques to improve the linearity of the unary digital-to-analog converter (DAC). We have developed two techniques based on magic square properties; a layout technique and a switching algorithm of unit current (capacitor) cells to canceling their systematic and/or random mismatch effects. Simulation results and discussions are provided for DAC linearity comparison in cases that the proposed magic square and conventional algorithms are used. We show that there are possibilities to obtain better unary DAC linearity by employing magic square algorithms, depending on mismatch characteristics, because the magic square has well-balanced 2-dimensional characteristics. There are rich mathematical research assets for magic squares and their usage would lead to linearity improvement algorithms for the DAC in nano-CMOS era.
Risk Impacts of Patientsf Information and Extensions of l-Diversity
Osamu Takaki, Takayuki Asao and Yoichi Seki
Journal of Technology and Social Science, Vol.4, No.1, pp.36-47, 2020.
Abstract: This paper describes the construction of an ontology to clarify and quantify the severity of health information recorded in medical databases. The proposed approach extends the definition of l-diversity to reduce the risk of an attacker identifying a patientfs health status based on medical data. The extended l-diversity is defined in accordance with the proposed ontology model. It is shown that the extended l-diversity satisfies the monotonicity property, based on which a process for anonymizing medical data is presented. Accordingly, the data satisfy the extended l-diversity and retain their usability to the greatest extent possible. In addition, the severity number of information regarding patients who visited or stayed in hospitals in Japan is estimated using our ontology model.
Facial Excise Support Equipment for Prevention of Pulmonary Aspiration Using Mouth Pressure Fluctuation
Akira Suzuki, Nobuaki Nakazawa, Yuuki Tanaka, Feng Wang and Toshikazu Matsui
Journal of Technology and Social Science, Vol.4, No.1, pp.48-53, 2020.
Abstract: There is a tendency that elderly persons decline in feeding and swallowing. It is well known that the oral training such as a facial exercise has an effect to facilitate a smoothness swallowing motion. This paper describes measurements of face exercises using PET plastic bottle and evaluations based on the electromyography (EMG). Here, the orbicularis oris muscle were focused for an evaluation. As results of APDF analysis, it could be confirmed that the motion of keep exhaling and fast exhaling, and using thin mouthpieces had effects to enhance the activity of the orbicularis oris muscle. Therefore, this paper also describes a training system based on results of analysis.
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