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Search Results: 1 - 10 of 224361 matches for " R. Maruyama "
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The Relation among the Solar Activity, the Total Ozone, QBO, NAO, and ENSO by Wavelet-Based Multifractal Analysis  [PDF]
Fumio Maruyama
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.66109
Abstract: There is an increasing interest in the relation between the solar activity and climate change. As for the solar activity, a fractal property of the sunspot number was studied by many works. In general, a fractal property was observed in the time series of dynamics of complex systems. The purposes of this study are to investigate the relations among the solar activity, total ozone, Quasi-Biennial Oscillation (QBO), the North Atlantic Oscillation (NAO), and El Ni?o-Southern Oscillation (ENSO) from a view of multi-fractality. To detect the changes of multifractality, we examined the multifractal analysis on the time series of the solar 10.7-cm radio flux (F10.7 flux), total ozone, QBO, NAO, and Ni?o3.4 indices. During the period 1950 and 2010, for the F10.7 flux and QBO index, the matching in monofractality or multifractality is observed and the increase and decrease of multifractality is similar; that is the change of multifractality is similar. In the same way, it is very similar, during the period 1985 and 2010, for the QBO and the total ozone, and during the period 1950 and 2010, for the QBO, and NAO and for the QBO, and Ni?o3.4. Compared to Ni?o3.4, the multifractality of NAO and QBO was strong and it turns out that they are undergoing unstable change.
Relationship between the Atmospheric CO2 and Climate Indices by Wavelet-Based Multifractal Analysis  [PDF]
Fumio Maruyama
Journal of Geoscience and Environment Protection (GEP) , 2019, DOI: 10.4236/gep.2019.71004
Abstract: Atmospheric concentrations of greenhouse gases are rising, leading to a positive radiative forcing of climate and an expected warming of surface temperatures. In general, fractal properties may be observed in the time series of the dynamics of complex systems. To study the relation between the atmospheric CO2 concentration and the climate indices, we investigated the change of fractal behavior of the CO2, the carbon isotope ratio (δ13C) of atmospheric CO2, the El Ni?o-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the North Atlantic Oscillation (NAO) indices using the multifractal analysis. When the atmospheric CO2 growth rate was large, the multifractality of CO2, δ13C in CO2, ENSO, and NAO was large and the changes were large from the change of fractality. The changes of CO2 and ENSO were closely related and the influence of the CO2 on the ENSO was strong from the change in fractality and wavelet coherence. When the El Ni?o occurred, the CO2 growth rate was large. The CO2 related to PDO, NAO, and global temperature from the change in fractality and wavelet coherence. Especially, the changes of CO2 and global temperature were closely related. When the global warming hiatus occurred, the multifractality of the global temperature was weaker than that of CO2 and the change of the global temperature was stable. These findings will contribute to the research of the relation between the atmospheric CO2 and climate change.
Relationship between the Sunspot Number and Solar Polar Field by Wavelet-Based Multifractal Analysis  [PDF]
Fumio Maruyama
Journal of Applied Mathematics and Physics (JAMP) , 2019, DOI: 10.4236/jamp.2019.75070
Abstract:
There is increasing interest in finding the relation between the sunspot number (SSN) and solar polar field. In general, fractal properties may be observed in the time series of the dynamics of complex systems, such as solar activity and climate. This study investigated the relations between the SSN and solar polar field by performing a multifractal analysis. To investigate the change in multifractality, we applied a wavelet transform to time series. When the SSN was maximum and minimum, the SSN showed monofractality or weak multifractality. The solar polar field showed weak multifractality when that was maximum and minimum. When the SSN became maximum, the fractality of the SSN changed from multifractality to monofractality. The multifractality of SSN became large before two years of SSN maximum, then that of the solar polar field became large and changed largely. It was found that the change in SSN triggered the change in the solar polar field. Hence, the SSN and solar polar field were closely correlated from the view point of fractals. When the maximum solar polar field before the maximum SSN was larger, the maximum SSN of the next cycle was larger. The formation of the magnetic field of the sunspots was correlated with the solar polar field.
Temperature and Heat Flux Distributions through Single and Double Window Glazing Nongray Calculation  [PDF]
Maatouk Khoukhi, Shigenao Maruyama
Smart Grid and Renewable Energy (SGRE) , 2011, DOI: 10.4236/sgre.2011.21003
Abstract: Accurate prediction of thermal radiation by applying rigorous model for the radiative heat transfer combined with the conduction and the convection has been performed for a single and double window glazing subjected to solar and thermal irradiation. The glass window is analysed as a non-gray plane-parallel medium disctritized to thin layer as-suming the glass material as participating media in one-dimensional case, using the Radiation Element Method by Ray Emission Model (REM2). The model allows the calculation of the steady-state heat flux and the temperature distribution within the glass cover. The spectral dependence of the relevant radiation properties of glass (i.e. specular reflectivity, refraction angle and absorption coefficient) is taken into account. Both solar and thermal incident irradiations are applied at the boundary surfaces using the spectral solar model proposed by Bird and Riordan. The optical constant of a commercial clear glass material have been used. The calculation has been performed during winter period and the effect of the thickness of the glass for a single glazing and of the air layer between the two panels for double glazing has been studied. The result shows that increasing the air layer, the steady heat flux decreases and the temperature distribution within the glass changes.
Positioning Training Tool for Radiography  [PDF]
Toshinori Maruyama, Hideki Yamamoto
Positioning (POS) , 2013, DOI: 10.4236/pos.2013.44029
Abstract:

Accurate positioning reduces the X-ray exposure of the subject and produces a valuable X-ray image for diagnosis. This paper describes the development of a positioning training tool that supports those studying to be radiological technologists in learning the positioning technique efficiently. Students perform the positioning on a personal computer using a three-dimensional computer graphics (3DCG) phantom constructed from computed tomography (CT) image data and confirm the produced plane image corresponding to the positioned phantom. It is expected that students will be able to undertake positioning training using our tool anywhere and at any time without using X-ray equipment. Repeated use of our training tool will help students attain a deep understanding of anatomy and acquire positioning skills efficiently and accurately.

Reciprocal Analysis of Sensible and Latent Heat Fluxes in a Forest Region Using Single Height Temperature and Humidity Based on the Bowen Ratio Concept  [PDF]
Toshisuke Maruyama, Manabu Segawa
Journal of Water Resource and Protection (JWARP) , 2016, DOI: 10.4236/jwarp.2016.87059
Abstract: Evapotranspiration in forests has been researched for a long time because it serves an important role in water resource issues and biomass production. By applying the reciprocal analysis based on the Bowen ratio concept to the canopy surface, the sum result of sensible and latent heat fluxes, i.e., actual evapotranspiration (ET), is estimated from engineering aspect using the net radiation (Rn) and heat flux into the ground (G). The new method uses air temperature and humidity at a single height by determining the relative humidity (rehs) using the canopy temperature (Ts). The validity of the method is confirmed by the latent heat flux (lE) and sensible heat flux (H) observed by mean of eddy covariance method. The heat imbalance is corrected by multiple regression analysis. The temporal change of lE and H at the canopy surface is clarified using hourly and yearly data. Furthermore, the observed and estimated monthly evapotranspiration of the sites are compared. The research is conducted using hourly data and the validation of the method is conducted using observed covariance at five sites in the world using FLUXNET.
Application of the Reciprocal Analysis for Sensible and Latent Heat Fluxes with Evapotranspiration at a Humid Region  [PDF]
Toshisuke Maruyama, Manabu Segawa
Open Journal of Modern Hydrology (OJMH) , 2016, DOI: 10.4236/ojmh.2016.64019
Abstract: Evapotranspiration acts an important role in hydrologic cycle and water resources planning. But the estimation issue still remains until nowadays. This research attempts to make clear this problem by the following way. In a humid region, by applying the Bowen ratio concept and optimum procedure on the soil surface, sensible and latent heat fluxes are estimated using net radiation (Rn) and heat flux into the ground (G). The method uses air temperature and humidity at a single height by reciprocally determining the soil surface temperature (Ts) and the relative humidity (rehs). This feature can be remarkably extended to the utilization. The validity of the method is confirmed by comparing of observed and estimated latent (lE) and sensible heat flux (H) using the eddy covariance method. The hourly change of the lE, H, Ts and rehs on the soil surface, yearly change of lE and H and relationship of estimated lE and H versus observed are clarified. Furthermore, monthly evapotranspiration is estimated from the lE. The research was conducted using hourly data of FLUXNET at a site of Japan, three sites of the United States and two sites of Europe in humid regions having over 1000 mm of annual precipitation.
Estimation of the Sensible and Latent Heat Fluxes by Reciprocal Analysis at an Arid and Semi-Arid Region  [PDF]
Toshisuke Maruyama, Manabu Segawa
Open Journal of Modern Hydrology (OJMH) , 2017, DOI: 10.4236/ojmh.2017.71003
Abstract: Sensible and latent heat flux at semi-arid and arid region, i.e., evapotranspiration, has been researched for long time because it serves an important role for water resource issues. However, the issues have not solved completely yet. Accordingly, by applying the Bowen ratio concept on the soil surface, the sensible and latent heat fluxes are reciprocally estimated using single height temperature (Tz) and humidity (rehz) with the net radiation (Rn) and heat flux into the ground (G). The procedure proposed by authors initially estimates the soil surface temperature (Ts) and the relative humidity (rehs) using optimization techniques. The method is remarkably effective to expand for estimating evapotranspiration at various regions. The validity of the method is confirmed by the latent heat flux (lE) and sensible heat flux (H) observed by the eddy covariance method. The hourly change of the lE, H, Ts and rehs on the soil surface, yearly change of lE and H and relationship of estimated lE and H versus observed are clarified. Yearly change of evapotranspiration is also estimated. The analysis is performed by general method (1), conventional method and general method (2). Above results are very useful for water resources issue and irrigation planning. The research is conducted using hourly data at eight globally dispersed sites using FLUXNET.
Relationships between pre-sunset electrojet strength, pre-reversal enhancement and equatorial spread-F onset
J. Uemoto, T. Maruyama, S. Saito, M. Ishii,R. Yoshimura
Annales Geophysicae (ANGEO) , 2010,
Abstract: The virtual height of the bottom side F-region (h'F) and equatorial spread-F (ESF) onsets at Chumphon (10.7° N, 99.4° E; 3.3° N magnetic latitude) were compared with the behaviour of equatorial electrojet (EEJ) ground strength at Phuket (8.1° N, 98.3° E; 0.1° N magnetic latitude) during the period from November 2007 to October 2008. Increase in the F-layer height and ESF onsets during the evening hours were well connected with the EEJ ground strength before sunset, namely, both the height increase and ESF onsets were suppressed when the integrated EEJ ground strength for the period from 1 to 2 h prior to sunset was negative. The finding suggests observationally that the pre-sunset E-region dynamo current and/or electric field are related to the F-region dynamics and ESF onsets around sunset.
Acetylene-Accelerated Alcohol Catalytic CVD Growth of Vertically Aligned Single-Walled Carbon Nanotubes
R. Xiang,E. Einarsson,J. Okawa,Y. Miyauchi,S. Maruyama
Physics , 2008,
Abstract: Addition of only 1% of acetylene into ethanol was found to enhance the growth rate of singlewalled carbon nanotubes (SWNTs) by up to ten times. Since acetylene is a byproduct of the thermal decomposition of ethanol, this suggests an alternative fast reaction pathway to the formation of SWNTs from ethanol via byproducts of decomposition. This accelerated growth, however, only occurred in the presence of ethanol, whereas pure acetylene at the same partial pressure resulted in negligible growth and quickly deactivated the catalyst. The dormant catalyst could be revived by reintroduction of ethanol, indicating that catalyst deactivation is divided into reversible and irreversible stages.
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