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EFFECTS OF SIDE ROUGHNESS ON BENT-WAVEGUIDE POLARIZATION CONVERTER
Get PDFThe fabrication process of a Si-wire waveguide yields sidewall roughness which scatters the propagating field. It is, therefore, important to understand the effects of the roughness on the propagating field of a functional waveguide device. In this article, a bent waveguide polarization converter with sidewall roughness is analyzed by the finite-difference time-domain method. It is found that the extinction ratio is decreased and the insertion loss is increased as the bend radius is decreased, regardless of the presence or absence of the sidewall roughness
IMPLEMENTATION OF AUTOMATIC RESONANCE COMPENSATION IN MRC-WPT USING FLEXIBLE COIL
Get PDFIn recent years, the number of mobile and wearable devices has been increasing, and there is growing interest in MRC-WPT as a power supply method for these devices. In this study, we proposed a system that automatically compensates the inductance fluctuation caused by coil deformation
Research on amusement method using catnip in MR space
Get PDFIn recent years, technologies that utilize the interaction between real and virtual space, such as AR and MR, have become a hot topic. This paper proposes a method to calculate the depth distance of a real object from a user for the purpose of communicating with a virtual character using a real object to reduce the technical distance between the virtual space and the real space.It has been difficult to obtain depth coordinates of small objects from MRHMD. In this paper, we propose a method to calculate the depth coordinates of small objects in MR space, such as the tip of a catnip, and verify the method with an amusement system. The proposed method was compared with the actual measurements and resulted in an error of about 0.001 m. The proposed method succeeded in calculating almost accurate depth coordinates
Efficiency improvement of a fluorescence detection system for radioisotope atoms generated at accelerators
Get PDFWe have been developing a laser spectroscopic method named OROCHI for the study of the nuclear structure of low-yield unstable nuclei produced by accelerators. Spin-polarized states are generated for RI atoms stopped in superfluid helium by optical pumping, and Zeeman level splitting and hyperfine structure splitting are measured by using the laser-radio frequency / microwave double resonance method. When atoms are introduced into superfluid helium, the absorption and emission wavelengths of the atoms are different. We take the advantage of the intriguing spectroscopic environment of superfluid helium. We aim to improve the efficiency of LIF(Laser Induced Fluorescence) detection to measure the unstable ^84Rb hyperfine structure splitting in superfluid helium at accelerator beamlines. For this purpose, we enlarged the intersection area between an excitation laser and an accelerated beam. We evaluated the effect of this modification
A SIMPLE METHOD FOR MEASURING VISCOSITY OF LIQUIDS : AIMING AT AN EVALUATION OF FOOD THICKNESS
Get PDFFood thickening is important to prevent aspiration in elderly, and the appropriate thickness may be varied by individual swallowing function. The purpose of this study is to propose a simple and quantitative method for measuring food thickness in comparison with the conventional evaluation methods. The method proposed in this study detects food thickness based on viscosity of foods. Key parts of this method are vibrators driven by voice coils, and the evaluation in this study is based on the impedance when the vibrators are driven at mechanical resonant frequency. In this study, the author measured several kinds of Newtonian liquids, which were different in viscosity and/or density. Density of some liquid samples was the same as that of water, and viscosity of those samples was ranging from 60.5mPa･s to 387mPa･s. Those samples showed decreased impedance relative to that of water, and the relative impedance was ranging from 97.46% to 94.25%
A STUDY OF WAYPOINT NAVIGATION FOR OUTDOOR MOBILE ROBOTS BY FUSING AERIAL PHOTOGRAPHS AND ELECTRONIC MAPS
Get PDFWaypoint navigation for autonomous mobile robots allows navigation safely and smoothly to the destination point by following predetermined waypoints that serve as route points. To assign waypoints, environmental maps are needed to accurately determine the current location and the moving direction of the mobile robot. In this paper, we propose a new waypoint navigation method using both aerial photographs and electronic maps. By fusing aerial photographs and electronic map data, waypoint navigation environmental maps can be generated without prior acquisition of environmental data by traveling. The effectiveness of the proposed system was demonstrated by using an actual autonomous mobile robot and generated environmental maps of outdoor environments to confirm the validity of the proposed waypoint navigation
A Study on Computation of Collision Probability in a Parallel Machines Model with Buffers
Get PDFLine production system is used for continuous production in manufacturing industry in order to improve production efficiency. The probability of occurring a collision is one of the most important factors in relation to the productivity of the line production system. In this paper, we present a simulation algorithm to compute collision probability in a parallel machines model with buffers. This simulation algorithm iteratively uses a method of deciding whether a collision occurs or not. This method makes use of two binary heaps to efficiently decide whether a collision occurs. Throughout simulations, we investigate the relationships between the number of machines, the number of buffers, tact time, and collision probability. Collision probability decreases as tact time increases, and there is a minimum tact time at which collision probability is about zero. The minimum tact time dramatically decreases as the number of machines increases. The minimum tact time decreases as the number of buffers increases. We confirm that the CPU time is independent of the number of buffers
The number of contacts concerning infectious disease and medical resource allocation methods on complex networks
Get PDFIt is desirable that infectious diseases such as COVID-19 and influenza end quickly. Cutting off infection routes from infection sources to hosts is very important. In order to control infecting virus effectively, we reveal the characteristics of infection sources and investigate ways to allocate medical resources. In order to investigate how much the sources of an infectious disease contribute to its outbreak, we introduce a new indicator, i.e., the number of times of infecting people with the infectious disease. This indicator is called the number of contacts. In order to obtain the number of contacts, we use the mathematical model on a network called the contact process. We obtain the number of contacts from simulation using the model, in which an infectious disease spreads. Then, we evaluate the number of contacts, and discuss correlation between the number of contacts and node’s centrality. Furthermore, we allocate medical resources to nodes in descending order of the node’s centrality. Then, we obtain the percentage of the number of uninfected nodes. From the obtained results, we discuss the usefulness of the number of contacts
LOCATION SET-COVERING PROBLEM TO COVER ALL DEMAND SITHIN A CERTAIN TIME
Get PDFDecision making in facility allocation problems involves a variety of factors, such as facility cost, time, and distance. In the location set-covering problem (LSCP), facility siting is employed as decision variables with the number of facilities as a cost factor. The problem is to find the minimum number and location of facilities that satisfy the time or distance to demand criteria. It is possible to find the siting of emergency services such as fire stations, schools, and libraries. In this study, we formulate the timed location set-covering problem (T-LSCP), which takes into account the passage of time in the LSCP. The model is based on the assumption that facilities are movable over time. Once a demand point is covered, the effect of the coverage remains for a certain time. Therefore, the number of facilities can be reduced compared to LSCP, as they do not need to be covered all the time. This problem can be applied to police patrols
The Lessons Learned from the Digital Extensive Reading Trial
Get PDFThe purpose of this research is to examine the feasibility of a digital extensive reading programme and the attitude of English-major college students toward the programme. The research was conducted in the department of English in a professional training college in Tokyo, which never offered compulsory extensive reading classes before. There were 20 participants, none of which had any experience of an extensive reading programme, or with a digital library before. The participants had one month of digital reading experience with Xreading. The research result revealed that the introduction of the digital library itself did not encourage students to establish English reading habits. The sheer amount of material to read online actually discouraged some students from reading at all. The concerns and the implications from the findings are discussed