Fuji, Japan

Fuji Tokoha University is a private university in Fuji City, Shizuoka Prefecture Japan. The predecessor of the school was founded in 1990, and it was chartered as a university in 2000. The university has three departments:College of Distribution EconomicsCollege of Environment and Disaster Research University Library Wikipedia.

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Shimano T.,Fuji Tokoha University | Nishimura T.,Tohoku University | Chiga N.,Tohoku University | Shibasaki Y.,Tohoku University | And 3 more authors.
Bulletin of Volcanology | Year: 2013

We develop an automatic system for the sampling of ash fall particles, to be used for continuous monitoring of magma ascent and eruptive dynamics at active volcanoes. The system consists of a sampling apparatus and cameras to monitor surface phenomena during eruptions. The Sampling Apparatus for Time Series Unmanned Monitoring of Ash (SATSUMA-I and SATSUMA-II) is less than 10 kg in weight and works automatically for more than a month with a 10-kg lead battery to obtain a total of 30 to 36 samples in one cycle of operation. The time range covered in one cycle varies from less than an hour to several months, depending on the aims of observation, allowing researchers to target minute-scale fluctuations in a single eruptive event, as well as daily to weekly trends in persistent volcanic activity. The latest version, SATSUMA-II, also enables control of sampling parameters remotely by e-mail commands. Durability of the apparatus is high: our prototypes worked for several months, in rainy and typhoon seasons, at windy and humid locations, and under strong sunlight. We have been successful in collecting ash samples emitted from Showa crater almost everyday for more than 4 years (2008-2012) at Sakurajima volcano in southwest Japan. © 2013 Springer-Verlag Berlin Heidelberg.

Kawaguchi S.,Australian Antarctic Division | Ishida A.,Fuji Tokoha University | Ishida A.,Japan Agency for Marine - Earth Science and Technology | King R.,Australian Antarctic Division | And 6 more authors.
Nature Climate Change | Year: 2013

Marine ecosystems of the Southern Ocean are particularly vulnerable to ocean acidification. Antarctic krill (Euphausia superba; hereafter krill) is the key pelagic species of the region and its largest fishery resource. There is therefore concern about the combined effects of climate change, ocean acidification and an expanding fishery on krill and ultimately, their dependent predators - whales, seals and penguins. However, little is known about the sensitivity of krill to ocean acidification. Juvenile and adult krill are already exposed to variable seawater carbonate chemistry because they occupy a range of habitats and migrate both vertically and horizontally on a daily and seasonal basis. Moreover, krill eggs sink from the surface to hatch at 700-1,000 m (ref.), where the carbon dioxide partial pressure (p CO 2) in sea water is already greater than it is in the atmosphere. Krill eggs sink passively and so cannot avoid these conditions. Here we describe the sensitivity of krill egg hatch rates to increased CO 2, and present a circumpolar risk map of krill hatching success under projected p CO 2 levels. We find that important krill habitats of the Weddell Sea and the Haakon VII Sea to the east are likely to become high-risk areas for krill recruitment within a century. Furthermore, unless CO 2 emissions are mitigated, the Southern Ocean krill population could collapse by 2300 with dire consequences for the entire ecosystem. © 2013 Macmillan Publishers Limited. All rights reserved.

Suzuki Y.,University of Tokyo | Nagai M.,Japan National Research Institute for Earth Science and Disaster Prevention | Maeno F.,University of Tokyo | Yasuda A.,University of Tokyo | And 5 more authors.
Earth, Planets and Space | Year: 2013

After a precursory phreatic stage (2008 to 2010), the 2011 Shinmoe-dake eruption entered a phreatomagmatic stage on January 19, a sub-Plinian and lava accumulation stage at the end of January, a vulcanian stage in February-April, and a second phreatomagmatic stage in June-August. Component ratio, bulk composition, and particle size of the samples helped us define the eruptive stages. The juvenile particles were first found in the January 19 sample as pumice (8 vol%) and were consistently present as scoria and pumice particles thereafter (generally ∼50 vol%, decreasing in weaker events). The January 19 pumice has water-quench texture. After the lava accumulation, particles of that lava origin came to account for 30∼70 vol% of the ash. The second phreatomagmatic stage is proposed because of fine ash and long eruption period. The SiO2 contents of bulk ash are lower in post-January 19, 2011 eruptions, reflecting lower average SiO2 contents in 2011 ejecta than in past ejecta. The free-crystal assemblages were two pyroxenes + plagioclase + Fe-Ti oxides until 2010; olivine joined the assemblage in 2011, when juvenile ash was erupted. This change is consistent with the absence or smaller sizes of olivine phenocrysts in past ejecta.

Watanabe E.,Japan Agency for Marine - Earth Science and Technology | Onodera J.,Japan Agency for Marine - Earth Science and Technology | Harada N.,Japan Agency for Marine - Earth Science and Technology | Honda M.C.,Japan Agency for Marine - Earth Science and Technology | And 10 more authors.
Nature Communications | Year: 2014

The future conditions of Arctic sea ice and marine ecosystems are of interest not only to climate scientists, but also to economic and governmental bodies. However, the lack of widespread, year-long biogeochemical observations remains an obstacle to understanding the complicated variability of the Arctic marine biological pump. Here we show an early winter maximum of sinking biogenic flux in the western Arctic Ocean and illustrate the importance of shelf-break eddies to biological pumping from wide shelves to adjacent deep basins using a combination of year-long mooring observations and three-dimensional numerical modelling. The sinking flux trapped in the present study included considerable fresh organic material with soft tissues and was an order of magnitude larger than previous estimates. We predict that further reductions in sea ice will promote the entry of Pacific-origin biological species into the Arctic basin and accelerate biogeochemical cycles connecting the Arctic and subarctic oceans.© 2014 Macmillan Publishers Limited. All rights reserved.

Yamamoto A.,Japan Agency for Marine - Earth Science and Technology | Yamamoto A.,Hokkaido University | Yamamoto A.,University of Tokyo | Kawamiya M.,Japan Agency for Marine - Earth Science and Technology | And 5 more authors.
Biogeosciences | Year: 2012

The largest pH decline and widespread undersaturation with respect to aragonite in this century due to uptake of anthropogenic carbon dioxide in the Arctic Ocean have been projected. The reductions in pH and aragonite saturation state in the Arctic Ocean have been caused by the melting of sea ice as well as by an increase in the concentration of atmospheric carbon dioxide. Therefore, future projections of pH and aragonite saturation in the Arctic Ocean will be affected by how rapidly the reduction in sea ice occurs. The observed recent Arctic sea-ice loss has been more rapid than projected by many of the climate models that contributed to the Intergovernmental Panel on Climate Change Fourth Assessment Report. In this study, the impact of sea-ice reduction rate on projected pH and aragonite saturation state in the Arctic surface waters was investigated. Reductions in pH and aragonite saturation were calculated from the outputs of two versions of an Earth system model with different sea-ice reduction rates under similar CO2 emission scenarios. The newer model version projects that Arctic summer ice-free condition will be achieved by the year 2040, and the older version predicts ice-free condition by 2090. The Arctic surface water was projected to be undersaturated with respect to aragonite in the annual mean when atmospheric CO2 concentration reaches 513 (606) ppm in year 2046 (2056) in new (old) version. At an atmospheric CO2 concentration of 520 ppm, the maximum differences in pH and aragonite saturation state between the two versions were 0.1 and 0.21 respectively. The analysis showed that the decreases in pH and aragonite saturation state due to rapid sea-ice reduction were caused by increases in both CO2 uptake and freshwater input. Thus, the reductions in pH and aragonite saturation state in the Arctic surface waters are significantly affected by the difference in future projections for sea-ice reduction rate. Our results suggest that the future reductions in pH and aragonite saturation state could be significantly faster than previously projected if the sea-ice reduction in the Arctic Ocean keeps its present pace. © 2012 Author(s). CC Attribution 3.0 License.

Takeyasu K.,Fuji Tokoha University | Kainosho M.,Otsuma Women's University
Journal of Intelligent Manufacturing | Year: 2014

In recent years, sea and air transport has become a big trend. Getting an optimal solution with minimum costs (freight cost, warehouse cost) under certain constraints (delivery due date etc.) must be sought. Formerly, we made a mathematical formulation of the fundamental case (a single supply site and a single demand site with multiple delivery dates/different delivery quantities) and next we expanded the objective function from considering transportation costs to considering transportation costs and warehouse stock fees. Under certain constraints, a minimum cost was pursued. In this paper, the objective function is expanded to the scheme which considers a reduced cost for the volume of lots. Here, a reduced cost by the discount of volume is also taken into account when multiple lots are transported using the same type of transport. A new selection method, "Multi-step tournament selection method" which is suitable for this problem is devised and utilized in this paper. Numerical examples are examined for the cases in which the discount of volume is considered. Theoretical optimal solution is derived by using genetic algorithm. An application of genetic algorithm to International Logistics is executed before by us. In this paper, the further expansion of constraints is executed and fruitful result is obtained, which contributes to the real management of International Logistics for the better decision making. © 2013 Springer Science+Business Media New York.

Watanabe E.,Japan Agency for Marine - Earth Science and Technology | Kishi M.J.,Japan Agency for Marine - Earth Science and Technology | Kishi M.J.,Hokkaido University | Ishida A.,Japan Agency for Marine - Earth Science and Technology | And 3 more authors.
Journal of Oceanography | Year: 2012

The response of phytoplankton to the Beaufort shelf-break eddies in the western Arctic Ocean is examined using the eddy-resolving coupled sea ice-ocean model including a lower-trophic marine ecosystem formulation. The regional model driven by the reanalysis 2003 atmospheric forcing from March to November captures the major spatial and temporal features of phytoplankton bloom following summertime sea ice retreat in the shallow Chukchi shelf and Barrow Canyon. The shelf-break warm eddies spawned north of the Barrow Canyon initially transport the Chukchi shelf water with high primary productivity toward the Canada Basin interior. In the eddy-developing period, the anti-cyclonic rotational flow along the outer edge of each eddy moving offshore occasionally traps the shelf water. The primary production inside the warm eddies is maintained by internal dynamics in the eddy-maturity period. In particular, the surface central area of an anti-cyclonic eddy acquires adequate light, nutrient, and warm environment for photosynthetic activity partly attributed to turbulent mixing with underlying nutrient-rich water. The simulated biogeochemical properties with the dominance of small-size phytoplankton inside the warm eddies are consistent with the observational findings in the western Arctic Ocean. It is also suggested that the light limitation before autumn sea ice freezing shuts down the primary production in the shelf-break eddies in spite of nutrient recovery. These results indicate that the time lag between the phytoplankton bloom in the shelf region following the summertime sea ice retreat and the eddy generation along the Beaufort shelf break is an important index to determine biological regimes in the Canada Basin. © 2012 The Oceanographic Society of Japan and Springer.

Watanabe E.,Japan Agency for Marine - Earth Science and Technology | Onodera J.,Japan Agency for Marine - Earth Science and Technology | Harada N.,Japan Agency for Marine - Earth Science and Technology | Aita M.N.,Japan Agency for Marine - Earth Science and Technology | And 2 more authors.
Biogeosciences | Year: 2015

Seasonal and interannual variability in the biogenic particle sinking flux was recorded using multi-year bottom-tethered sediment trap mooring systems in the Northwind Abyssal Plain (Station NAP: 75°N, 162°W, 1975 m water depth) of the western Arctic Chukchi Borderland. Trapped particle flux at a median depth of 184 m had an obvious peak and dominance of sea ice-related diatom assemblages in August 2011. The observed particle flux was considerably suppressed throughout summer 2012. In the present study, the response of ice algal production and biomass to wind-driven changes in the physical environment was addressed using a pan-Arctic sea ice-ocean modeling approach. A sea ice ecosystem with ice algae was newly incorporated into the lower-trophic marine ecosystem model, which was previously coupled with a high-resolution (i.e., 5 km horizontal grid size) sea ice-ocean general circulation model. Seasonal model experiments covering 2-year mooring periods indicated that primary productivity of ice algae around the Chukchi Borderland depended on basin-scale wind patterns via various processes. Easterly winds in the southern part of a distinct Beaufort High supplied nutrient-rich water for euphotic zones of the NAP region via both surface Ekman transport of Chukchi shelf water and vertical turbulent mixing with underlying nutricline water in 2011. In contrast, northwesterly winds flowing in the northern part of an extended Siberian High transported oligotrophic water within the Beaufort Gyre circulation toward the NAP region in 2012. The modeled ice algal biomass during summer reflected the differences in nutrient distribution. The modeled sinking flux of particulate organic nitrogen (PON) was comparable with the time series obtained from sediment trap data in summer 2011. In contrast, lateral advection of ice algal patches of shelf origin during a great cyclone event may have caused a modeled PON flux bias in 2012. Sensitivity experiments revealed several uncertainties of model configurations of ice algal productivity, particle sinking speed, and grazing activities. Extending the year-long measurements is expected to help illustrate the more general features of ice-related biological processes in the Arctic Ocean. © Author(s) 2015.

Aburai T.,Doshisha University | Takeyasu K.,Fuji Tokoha University
2014 Joint 7th International Conference on Soft Computing and Intelligent Systems, SCIS 2014 and 15th International Symposium on Advanced Intelligent Systems, ISIS 2014 | Year: 2014

Social Networking Service (SNS) is prevailing rapidly in Japan in recent years. The most popular ones are Facebook, mixi, and Twitter, which are utilized in various fields of life together with the convenient tool such as smart-phone. In this work, a questionnaire investigation is carried out in order to clarify the current usage condition, issues and desired functions. More than 1,000 samples are gathered Bayesian network is utilized for this analysis. Sensitivity analysis is carried out by setting evidence to all items. This enables overall analysis for each item We analyzed them by sensitivity analysis and some useful results were obtained. We have presented the paper concerning this. But the volume becomes too large, therefore we have split them and this paper shows the latter half of the investigation result by setting evidence to Bayesian Network parameters. Differences in usage objectives and SNS sites are made clear by the attributes and preference of SNS users. They can be utilized effectively for marketing by clarifying the target customer through the sensitivity analysis. © 2014 IEEE.

Ishii Y.,Osaka International University | Takeyasu K.,Fuji Tokoha University
2014 Joint 7th International Conference on Soft Computing and Intelligent Systems, SCIS 2014 and 15th International Symposium on Advanced Intelligent Systems, ISIS 2014 | Year: 2014

Focusing that the equation of the exponential smoothing method (EMS) is equivalent to (1,1) order ARMA model equation, a new method of estimation of the smoothing constant in the exponential smoothing method was proposed before by us which satisfied the minimum variance of forecasting error. In this paper, we utilize the above stated theoretical solution. Firstly, we estimated the ARMA model parameter and then estimate the smoothing constants. Thus the theoretical solution is derived in a simple way and it may be utilized in various fields. This new method shows that it is useful for the time series that has various trend characteristics. The effectiveness of this method should be examined in various cases. © 2014 IEEE.

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