scholarly journals Simulation-Based Clarification of Appropriate Factors for Presenting Phosphene in Two Directions Avoiding Electrical Interference

2021 ◽  
Vol 8 (8) ◽  
pp. 111
Author(s):  
Manami Kanamaru ◽  
Phan Xuan Tan ◽  
Eiji Kamioka

Walking support systems are essential for blind people. In this study, the presentation of phosphene position is focused on as a method to detect obstacles for blind people. When the phosphene is used in a walking support system, it is necessary to accurately present the phosphene in at least three directions of the visual field. Controlling the presentation of phosphene position has been reported in several previous studies. However, methodologies to present phosphene in multiple directions without any electric interference have not as yet been investigated. In this study, therefore, appropriate stimulation factors are clarified by the simulation of electric field on the eyeball surface which is strongly related to the presentation of phosphene position in the visual field. As a result of the simulation, it was revealed that the distance of each electrode does not give a significant effect to the eyeball surface. However, the phase of alternating current significantly changed the electric field on the eyeball surface. From investigation of the simulation results, it was clarified that the transition of the electric field on the eyeball surface can be controlled using anti-phase stimulation. In addition, the methodology to present the phosphene at least in two directions was verified.

Author(s):  
Manami, K Et.al

A walking support system with phosphenes for blind people has been investigated. Phosphene is a phenomenon where a flash of light is recognized in the brain by giving an electrical stimulus to human’s visual pathway. Phosphenes can be perceived even if their eyes are closed or they are blind. It has been clarified that phosphenes can be induced to several directions if electrodes placements are precisely selected. When phosphenes are presented to two directions for recognizing two obstacles, two pairs of electrodes must be applied. In such a case, however, the electrical interference occurs due to the short distance between electrodes. In the practical use of the phosphene-based walking support system, the avoidance of electrical interference is significant in order to present the phosphenes precisely. Therefore, in this paper, we first practically investigate the electrical interference by considering the difference in phosphene induction generated by a single pair of electrodes and by two pairs of electrodes. Then, the solutions to avoid the electrical interference are discussed.


2012 ◽  
Vol 271-272 ◽  
pp. 21-25
Author(s):  
Hu Jun Jia ◽  
Yin Tang Yang ◽  
Lian Jin Zhang ◽  
Bao Xing Duan

A novel 4H-SiC MESFET with stepped-channel (stepped-spacer) structure is proposed for the first time and analyzed by 2D numerical simulation. Based on the stepped buried oxide structure of SOI which can produce additional electrical Electric field peaks, much more advantages can be obtained through a stepped-channel structure compared to that of the field terminal technology, such as an obvious increase of the breakdown voltage which is equal to the electric field to the path integral, and the lower capacitances lead to a higher cut-off frequency. The simulation results show that a 100% higher saturated drain current and a 153% larger breakdown voltage can be obtained utilizing the stepped-channel structure MESFET than those of the conventional counterpart.


Author(s):  
Soraya Rahma Hayati ◽  
Mesran Mesran ◽  
Taronisokhi Zebua ◽  
Heri Nurdiyanto ◽  
Khasanah Khasanah

The reception of journalists at the Waspada Daily Medan always went through several rigorous selections before being determined to be accepted as journalists at the Waspada Medan Daily. There are several criteria that must be possessed by each participant as a condition for becoming a journalist in the Daily Alert Medan. To get the best participants, the Waspada Medan Daily needed a decision support system. Decision Support Systems (SPK) are part of computer-based information systems (including knowledge-based systems (knowledge management)) that are used to support decision making within an organization or company. Decision support systems provide a semitructured decision, where no one knows exactly how the decision should be made. In this study the authors applied the VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) as the method to be applied in the decision support system application. The VIKOR method is part of the Multi-Attibut Decision Making (MADM) Concept, which requires normalization in its calculations. The expected results in this study can obtain maximum decisions.Keywords: Journalist Acceptance, Decision Support System, VIKOR


2020 ◽  
Vol 14 (1) ◽  
pp. 12-28
Author(s):  
Jingang Jiang ◽  
Yihao Chen ◽  
Xuefeng Ma ◽  
Yongde Zhang ◽  
Zhiyuan Huang ◽  
...  

Background: Portable life support system is used in the battlefield, disaster and in other special circumstances such as in space exploration, and underground survey to give the wounded a life support. The most dangerous period for the injured is the first hour after an injury, which is a crucial time for treatment. If the patient's vital signs were stabilized, more than 40% of the injured could be saved. The staff can efficiently complete the task if they get effective and stable vital signs during the operation. Therefore, in order to reduce the risk of disaster and battlefield mortality to improve operational safety and efficiency, it is necessary to study the portable life support system. Objective: The study aimed to provide an overview of recent portable life support system and its characteristics and design. Methods: This paper introduces the patents and products related to a portable life support system, and its characteristics and application. Results: This paper summarizes five kinds of portable life support systems which are box type, stretcher type, bed type, backpack type and mobile type. Moreover, the characteristics of different portable life support systems are analyzed. The paper expounds the problems of different types of portable life support systems and puts forward improvement methods to solve the problems. Finally, the paper points out the future development of the system. Conclusion: Portable life support system plays an increasingly important role in health care. In terms of the structure, function and control, further development and improvements are needed, along with the research on portable life support system.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1011
Author(s):  
Andi Syahrullah Sulaimana ◽  
Chao-Kai Chang ◽  
Chih-Yao Hou ◽  
Bara Yudhistira ◽  
Fuangfah Punthi ◽  
...  

This study aims to determine the physicochemical quality of seagrape (Caulerpa lentillifera) as a freshness label for products cultivated in different seasons. The applied post-harvest storage experiments compared between, within and without seawater that led to oxidative stress conditions. Water content, malondialdehyde (MDA) compound, total phenolic content (TPC), and chlorophyll content were observed at 0, 3, 6, and 9 days of storage. The storage without seawater showed sharper quality reductions by reaching 20–40% of water loss, 70–90% of MDA production, 15–25% of TPC reduction, and 40–60% of total chlorophyll degradation. The storage within seawater showed lower quality reductions due to the specific growth rates still reaching 5–10%. This study found that the greater the physicochemical quality, the slower the decomposition rates of the stored seagrape during storage. Therefore, the seagrapes’ obvious discoloration occurred earlier in winter, followed by summer and spring. Kinetics of chlorophyll degradation on seagrape in different seasons meet different order-reactions during storage. Furthermore, alternating current electric field (ACEF) treatment with 125 kV/m of intensity for 60 min can lower the spring seagrapes’ physicochemical quality by reaching 10–30% of inhibition, resulting in the shelf-life extension for up to 12 days of post-harvest storage.


2012 ◽  
Vol 503-504 ◽  
pp. 731-734
Author(s):  
Xiao Xu Liu ◽  
Min Chen ◽  
Ai Hua Tang

The engine model with 4 cylinders is built by SolidWorks, the kinematics and dynamics simulations of the engine virtual prototype are done by COSMOSMotion, the results of kinematics simulation are checked, there are very small errors between the simulation results and the calculation results according to formulas. The mainly results of dynamics simulation are given. The simulation result consists with the parameters of the engine.


2011 ◽  
Vol 189-193 ◽  
pp. 2535-2538 ◽  
Author(s):  
Hong Yan ◽  
Wen Xian Huang

The thixo-forging of magnesium matrix composite was analyzed with computer numerical simulation based on rigid viscoplastic finite element method. The constitutive model of SiCp/AZ61 composite was established in our prior literature. Behavior of metal flow and temperature field were obtained. The differences between traditional forging and thixo-forging processes were analyzed. Results indicated that thixo-forging was better in filling cavity than forging. Simulation results were good agreement with experimental ones.


2021 ◽  
pp. 1-32
Author(s):  
Vu Linh Nguyen ◽  
Chin-Hsing Kuo ◽  
Po Ting Lin

Abstract This article proposes a method for analyzing the gravity balancing reliability of spring-articulated serial robots with uncertainties. Gravity balancing reliability is defined as the probability that the torque reduction ratio (the ratio of the balanced torque to the unbalanced torque) is less than a specified threshold. The reliability analysis is performed by exploiting a Monte Carlo simulation (MCS) with consideration of the uncertainties in the link dimensions, masses, and compliance parameters. The gravity balancing begins with a simulation-based analysis of the gravitational torques of a typical serial robot. Based on the simulation results, a gravity balancing design for the robot using mechanical springs is realized. A reliability-based design optimization (RBDO) method is also developed to seek a reliable and robust design for maximized balancing performance under a prescribed uncertainty level. The RBDO is formulated with consideration of a probabilistic reliability constraint and solved by using a particle swarm optimization (PSO) algorithm. A numerical example is provided to illustrate the gravity balancing performance and reliability of a robot with uncertainties. A sensitivity analysis of the balancing design is also performed. Lastly, the effectiveness of the RBDO method is demonstrated through a case study in which the balancing performance and reliability of a robot with uncertainties are improved with the proposed method.


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