In this study, we attempted to clarify the MAMA of broadband noise in virtual space. In the previous studies, MAMA has been measured by the method of constant stimuli. However, The results should not be taken as an estimate of the average human MAMA due to the inappropriate fitting method. Therefore, we re-examined the MAMA by QUEST+ method. In the psychophysical experiment, the subject was asked to answer the direction of movement of a circularly moving sound image at an equidistant distance of 1.5 m from the subject on a horizontal plane, using VR sound with headphones. The moving speed was at 8[deg/sec]. 9 subjects participated in this experiment, and the average MAMA were 3[deg] at 0[deg], 14[deg] at 45[deg], and 36[deg] at 90[deg]. These results indicate that the MAMA of broadband noise is larger in virtual space than in real space, and the manner of its increase was linear. By the results of the QUEST+ method, it was concluded that measurement accuracy is almost the same. And the measurement efficiency was higher than the method of constant stimuli since there are fewer procedures to calculate confidence intervals.

A computational method is proposed for interactions between deformable objects and fluid flows using the immersed boundary method and the mass-spring model. In the proposed method, the direct-forcing immersed boundary (DF/IB) method by Uhlmann is used for the computation of fluid-solid interaction. Multiple mass points are set up on the surface of a solid object and connected to each other with spring-dashpot model. The distinct element method (DEM) is used for the calculation of solid-solid and solid-wall contact forces. The proposed method is applied to lid-driven cavity flow problems with multiple deformable solid objects. The results demonstrated that the proposed method enables us to calculate the deformations of the multiple deformable solid objects due to the fluid-solid and solid-solid interactions.

Numerical simulation of particle filtration is performed using the MICS (Multiphase lncompressible flow solver with Collocated grid System) for multiphase flows and the DEM (Discrete Element Method) for uncharged or charged particle dynamics. This study deals with micro-particles and fluid flows through a single pore, which is larger than the particle size, modeled with two solid objects at the micro-scale. For an understanding of the effect of the electrostatic force between the electric-charged particles and objects, the interaction force is implemented based on Coulomb's law. The computational results show that the number density of the particles around the objects tends to be high by giving the electrostatic attractive force between the negatively charged particles and the positively charged objects. It is confirmed that there is a possibility of improving the filtration performance by the electrostatic attractive force, in addition to increasing the pore size at the same time under the given conditions.

Pathological diagnosis is an important diagnostic technique to determine a medical treatment policy. In the standard method, diagnosis of tissue slices has been investigated based on the visual inspection by microscope. However, it is difficult to evaluate a state of disease in a quantitative manner using the current methodology. Here, we propose a novel pathological diagnosis method focusing on the physical characteristics of tissue sections depending on the difference of disease state. We have found that the cracking pattern caused by applying tension to tissue sections depends on the pathological condition. By adapting such cracking pattern as a quantitative index for pathological diagnosis, it becomes possible to perform pathological diagnosis in a reliable and quantitative manner.

Information Floating (IF) is a method of delivering information to mobile nodes in target areas preventing unnecessary transmissions by permitting mobile nodes to transmit data via wireless direct links only in Transmittable Areas (TAs). IF can virtually accumulate data by making mobile nodes transmit multiple different data in the same TAs. In addition, the cooperation of multiple TAs reaccumulates temporarily lost data. In this paper, we first consider reaccumulation with the cooperation of two TAs while assuming that these TAs are points on a road. We classify the system states into two kinds based on how well the reaccumulation works using simulation results and estimate the node density representing the boundary between these two states using approximate theoretical analysis. The numerical and simulation results show that we can estimate node density to realize sufficient reaccumulation. We then show how to extend the TAs based on the above results to achieve sufficient reaccumulation and show that the proposed method is effective.

Many helmet antennas operating in the UHF band have been reported. In our laboratory, helmet antennas for disaster prevention that operates in the VHF band have been considered, and all of them have horizontal polarization and almost omnidirectional radiation patterns in the horizontal plane. In this paper, an antenna on the helmet for disaster prevention is created using a disk-loaded monopole antenna which is very low-profile and has a vertically polarized and omnidirectional radiation pattern in the horizontal plane. The VSWR characteristics, radiation pattern, and electric field distribution of this proposed antenna are analyzed using an electromagnetic field simulator, and the validity of the analysis results is confirmed through prototyping and measurement. As a result, it was confirmed that the proposed antenna can be used in the VHF band and has an omnidirectional radiation pattern in the horizontal plane. In addition, radiation in the direction of the head was reduced, and good VSWR characteristics were got even in close proximity to the human head phantom model.

In this study, we evaluated and compared the communication distance of various magnetic coupling methods using a magnetic coupling human body transceiver that we developed. The coupling schemes considered were a general inductive coupling scheme (non-resonant coupling scheme) and two types of resonant coupling schemes (low-Q resonant coupling scheme and high-Q resonant coupling scheme). First, communication characteristics were evaluated by computer simulation based on the specifications of the transceiver. Notably, when linear RLS equalizers were applied, the low-Q and high-Q resonant coupling schemes significantly improved the BER noise and transmit power characteristics compared to the non-resonant coupling schemes. Next, transmission and reception experiments were conducted using the magnetic coupling human body transceiver with a transmission frequency of 2 MHz, bit rate of 500 kbps, and linear equalizer, and the low-Q and high-Q resonant coupling systems extended the communication distance by a factor of 2 and 3, respectively, compared to the non-resonant coupling system.

In the present paper, we shall put forward an optimal control scheme to suppress the susceptible population as well as the involved economic loss with a fundamental SIR model on the basis of the Pontryagin's maximum principle theory. From the present numerical simulation results, it will be elucidated that there exists an optimal control scheme concerned with the control variable related to a ratio between the basic reproduction number and effective one under maximization scheme in terms of an appropriate objective function defined in the maximum principle approach. As a special case apart from the economic loss, it is found that the present results are reduced to the previous ones in which the economic loss was ignored in the objective function. Furthermore one may elucidate the dependence of the susceptible population and the economic loss on model parameters related to the degree the economic loss in the objective function as well as on the minimal ratio under optimal control. Then one may conclude that the susceptible populations are properly proportional to the economic loss under the presently proposed optimal control based on the maximum principle.