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Response of understory vegetation over 10 years after thinning in an old-growth cedar and cypress plantation overgrazed by sika deer in eastern Japan

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Forest Ecosystems 2017年第2期4卷 93-102页

作者： atsushi tamura Masanobu Yamane Division of Forest Research and Nature Restoration Planning Kanagawa Prefecture Natural Environment Conservation Center 657 Nanasawa AtsugiKanagawa 243-072 Japan

Background： Forest management strategies such as thinning have long been used to enhance ecosystem functions, especially in *** in plantations with high deer density, however, may not yield a desired increase in understory vegetation because deer graze on germinating plants after ***, we examine the changes in understory vegetation after thinning in plantations that have been overgrazed by sika deer to provide insight into the effects of thinning on ecosystem functions such as soil conservation and biological ***： We conducted our survey in the Tanzawa Mountains of eastern *** surveyed the change in understory vegetation within and outside of three deer exclosures on a single slope with three levels of understory vegetation cover： sparse（1%, exclosure ＂US＂）, moderate（30%, exclosure ＂MM＂）, and dense（80%, exclosure ＂LD＂） over10 years after a 30% thinning of an old-growth cedar and cypress plantation which was overgrazed by sika ***： Understory vegetation cover, biomass and species richness increased within and outside the ＂US＂ and＂MM＂ exclosures after thinning, and biomass was greater within than outside the exclosures at 10 years after *** species dominated both ＂US＂ and ＂MM＂ exclosures before thinning, and trees and shrubs dominated within the exclosures over time after *** contrast, unpalatable, grazing-tolerant, perennial,and annual species increased outside the ＂US＂ and ＂MM＂ *** noticeable changes were observed within and outside the ＂LD＂ exclosure when compared with the ＂US＂ and ＂MM＂ ***： Our results suggest that thinning a stand by 30% based on volume resulted in an increase in understory vegetation cover mainly composed of both unpalatable and grazing-tolerant species in a plantation forest where understory vegetation is sparse or moderate and sika deer density is *** emphasize that establishing deer exclosures or controlling deer is essential to ma

关键词： Biomass Deer exclosure Grazing-tolerant species Understory cover Unpalatable species

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Overview of BIM Implementation in Singapore and Japan

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Journal of Civil Engineering and Architecture 2016年第12期10卷 1305-1312页

作者： Takashi Kaneta Shuzo Furusaka atsushi tamura Nisi Deng Department of Architecture and Architectural Engineering Kyoto University Kyoto 615-8540 Japan

This paper aims to overview BIM （building information modeling） implementation in Singapore and to clarify the problems concerned with BIM in Singapore and Japan. The Singapore BIM Roadmap and related policies developed by BCA （Building and Construction Authority） are introduced at first along with the background and environment in Singapore. Despite of the assessment from Japan, BIM implementation in Singapore is not always perfect and well-equipped according to the authors＇ interviews to Japanese general contractors operating in Singapore. Japanese general contractors have ability to produce and coordinate design drawings and shop drawings by hiring in-house architects and engineers. The client and the architects can reduce project risk concerning design and drawings by transferring it to the general contractor. The authors discuss the problems on project management to show the strategy to develop the new version of BIM, hoping to share the value with all of the stakeholders of the project.

关键词： Building information modeling general contractor architect drawing project management.

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Sahara’s surface transformation forced an abrupt hydroclimate decline and Neolithic culture transition in northern China

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The Innovation 2024年第1期5卷 70-79页

作者： Yandong Hou Hao Long Sumiko Tsukamoto Zhengyao Lu Jie Chen Daniel EIbarra Toru tamura Qiong Zhang Weiyi Sun Jingran Zhang Lei Gao Manfred Frechen Ji Shen State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences(NIGLAS)Nanjing 210008China Leibniz Institute for Applied Geophysics(LIAG) Department of Geochronology30655 HannoverGermany Department of Physical Geography and Ecosystem Science Lund University22100 LundSweden Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Institute at Brown for Environment and Society and Department of Earth Environmentaland Planetary SciencesBrown UniversityProvidenceRI 02912USA Geological Survey of Japan National Institute of Advanced Industrial Science and TechnologyTsukubaIbaraki 305-8567Japan Graduate School of Frontier Sciences University of TokyoKashiwaChiba 277-8561Japan Department of Physical Geography and Bolin Centre for Climate Research Stockholm University10691 StockholmSweden School of Geography Nanjing Normal UniversityJiangsu Centre for Collaborative Innovation in Geographical Information Resource Development and ApplicationKey Laboratory of Virtual Geographic EnvironmentMinistry of Education of ChinaNanjing 210023China School of Geography and Ocean Science Nanjing UniversityNanjing 210023China

The remote forcing from land surface changes in the Sahara is hypothesized to play a pivotal role in modulating the intensity of the East Asian summer monsoon(EASM)through ocean-atmospheric *** modulation has far-reaching consequences,particularly in facilitating societal shifts documented in northern ***,we present a well-dated lake-level record from the Daihai Lake Basin in northern China,providing quantitative assessments of Holocene monsoonal precipitation and the consequent migrations of the northern boundary of the *** reconstruction,informed by a water-and-energy balance model,indicates that annual precipitation reached700 mm during 8–5 ka,followed by a rapid decline to tween 5 and 4 *** shift coherently aligns with a signi550 mm be-ficant300 km northwestward movement of the EASM northern boundary during the Middle Holocene(MH),in contrast to its current *** findings underscore that these changes cannot be entirely attributed to orbital forcing,as corroborated by simulation *** model simulations deployed in our study suggest that the presence of the Green Sahara during the MH significantly strengthened the EASM and led to a northward shift of the monsoon rainfall ***,the Sahara’s reversion to a desert landscape in the late Holocene was accompanied by a corresponding southward retraction of monsoon *** dramatic hydroclimate changes during5–4 ka likely triggered or at least contributed to a shift in Neolithic cultures and societal transformation in northern *** decreasing agricultural productivity,communities transitioned from millet farming to a mixed rainfed agriculture and animal husbandry ***,our findings elucidate not only the variability of the EASM but also the profound implications of a remote forcing,such as surface transformations of the Sahara,on climatic changes and cultural evolution in northern China.

关键词： Holocene monsoon abrupt

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Jurassic-Cretaceous Boundary Strata of the Somanakamura Group in NE Japan and their Correlation with Coeval Terrestrial Deposits in China

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Acta Geologica Sinica(English Edition) 2015年第1期89卷 285-299页

作者： LI Wei WAN Xiaoqiao atsushi MATSUOKA ZHANG Shuqin QU Haiying Tsubasa tamura Kohei YOSHINO State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Department of Geology Niigata University Research Center of Paleontology and Stratigraphy Jilin Univercity

Defining the Jurassic-Cretaceous boundary is a controversy in stratigraphic study of the world. It has been widely accepted that this boundary can be defined at the bottom of Berriasian in Tetbys, with the appearance of the ammonite Berriasellajacobi dating to ca. 145 Ma. However, it is difficult for the widespread terrestrial deposits in China to correlate with the international standard of marine facies. The Somanakamura Group in Japan is represented by a succession of marinecontinental transitional strata. It provides a bridge of marine and nonmarine stratigraphic correlation. The ammonite and radiolarian fossils preserved in this group suggest an age from Bajocian to early Valanginian. The J-K boundary was defined in or atop the Tomizawa Formation of the group according to the ammonite data. The present authors study the fossil spores and pollen newly found from the Tomizawa and Koyamada formations. Three assemblages have been recognized. They are Assemblage 1 （Cyathidites-Classopollis） from the upper part of the Tomizawa Formation, Assemblage 2 （Cyathidites-Jiaohepollis） from the lower part of the Koyamada Formation, and Assemblage 3 （Cyathidites-Spheripollenites-Ephedripites） from the middle to upper part of the Koyamada Formation. With the reference of ammonite evidence, the J-K boundary can be defined between Assemblage 1 and Assemblage 2. This palynological J-K boundary can be correlated with that of terrestrial sequence in China. However, local biostratigraphy imply that the continental J-K boundary in China is of 135 or 137 Ma age. It has a considerable discrepancy from the marine standard. Biogeographically, the distribution pattern of spores and pollen in southern China is in accordance with that in the Somanakamura Group, which parallels the Tuchengzi Formation in northeastern China. By the palynological correlation between the Somanakamura Group and the strata in southern China, and then with the sequence in northeastern China, it is suggested that th

关键词： Somanakamura Group Jurassic-Cretaceous boundary ammonites spores and pollen,Tomizawa Formation Koyamada Formation Tuchengzi Formation

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Increasing spatial coverage in rough terrain and vegetated areas using InSAR optimized pixel selection:application to Tohoku,Japan

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Geo-Spatial Information Science 2022年第2期25卷 295-311页

作者： Tamer ElGharbawi Masayuki tamura Civil and Earth Resources Engineering Department Kyoto UniversityKyotoJapan

One of the major limitations of using Interferometric Synthetic Aperture Radar(InSAR)in time series analysis is the low-phase coherence associated with rough terrain and vegetated areas,which results in limited spatial coverage in such *** scatterers technique was introduced to overcome this limitation using time-series ***,identifying major scatterers within a pixel requires the single-looked pixels oversampling which can be a demanding process especially with large interferometric stacks and vast study ***,using multilooked temporal coherent pixels was proposed to increase processing efficiency and coverage by utilizing distributed targets,but this technique may exclude pixels with reliable phase returns because of their temporal varying neighboring *** this paper,we propose a technique to identify multilooked temporal stable pixels with reliable phase returns independent of their neighboring *** conduct a simulation analysis to relate the spatial coherence of a pixel with its expected temporal correlation in the time series analysis *** found that a liberal temporal correlation threshold of 0.53 in multilooked pixels stack is equivalent to a spatial coherence threshold of 0.2 when using number of looks of 9,which is considered acceptable in temporal coherent pixels,in terms of phase standard *** these findings to study the 2011 Tohoku earthquake in the northeastern part of Japan resulted in increasing the number of usable pixels and spatial coverage index by nearly 50.4%and 36.8%,respectively,compared to the temporal coherent ***,we propose an approach to integrate GPS observations with InSAR time series analysis,which resulted in deformation maps of the megathrust 2011 Tohoku earthquake with mean RMSE of 11.4 mm and a correlation of 98%in comparison to GPS observations.

关键词： 2011 Tohoku earthquake temporal stable pixels coherence phase noise GPS coverage index

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Pediatric kidney transplantation during the COVID-19 pandemic

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World Journal of Clinical Cases 2022年第34期10卷 12494-12499页

作者： Hiroshi tamura Department of Pediatrics Kumamoto UniversityKumamoto 860-8556Japan

A waiting list for non-emergency transplant medical care was recommended in the first half of 2020 due to the coronavirus disease 2019(COVID-19)***,the number of kidney transplants temporarily ***,the waiting list for transplant medical care was lifted in the latter half of 2020 with the establishment of a polymerase chain reaction test system and the spread of infection *** basic stance is to recommend vaccination to posttransplant recipients,recipients,and donors who are scheduled to undergo transplantation,and their families,with the start of vaccine therapy in *** mortality rate of patients undergoing kidney transplants who had COVID-19 is slightly higher than healthy persons,and acute kidney injury was reported to lead to graft ***,pediatric cases of severe disease are rare and without *** transplantation medical care will be continuously provided by implementing infection prevention and treatments based on the latest evidence,promoting donated kidney transplantation,and hoping that pediatric patients with renal failure will grow up healthy,both physically and mentally,and become independent members of society,just like healthy children.

关键词： Kidney transplantation COVID-19 pandemic Children

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Dynamic robust optimal reorder point with uncertain lead time and changeable demand distribution

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第12期11卷 938-945页

作者： Masaki tamura Kazuko MORIZAWA Hiroyuki NAGASAWA Department of Electrical and Information Systems Engineering Graduate School of EngineeringOsaka Prefecture University Osaka Prefectural College of Technology

In fixed order quantity systems,uncertainty in lead time is expressed as a set of scenarios with occurrence probabilities,and the mean and variance in demand distribution are supposed to be changeable according to a known pattern.A new concept of "dynamic robust optimal reorder point" is proposed in this paper and its value is calculated as a "robust optimal reorder point function with respect to reorder time".Two approaches were employed in determining the dynamic optimal reorder *** first is a shortage rate satisfaction approach and the second is a backorder cost minimization *** former aims at finding the minimum value of reorder point at each reorder time which satisfies the condition that the cumulative distribution function (CDF) of shortage rate under a given set of scenarios in lead time is greater than or equal to a basic CDF of shortage rate predetermined by a *** the latter approach,the CDF of closeness of reorder point is defined at each reorder time to express how close to the optimal reorder points under the set of scenarios,and the dynamic optimal reorder point is defined according to stochastic *** numerical examples demonstrate the features of these dynamic robust optimal reorder points.

关键词： Reorder point Lead time Robust optimum Uncertainty Scenario

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IMPROVEMENT OF BUBBLE MODEL FOR CAVITATING FLOW SIMULATIONS

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Journal of Hydrodynamics 2009年第1期21卷 41-46页

作者： tamura Y. MATSUMOTO Y. Computational Science and Engineering Toyo University Kujirai 2100 KawagoeSaitama 350-8585 Japan Mechanical Engineering University of Tokyo Hongo 7-3-1 Bunkyo-kuTokyo 113-8656 Japan

In the present research, a bubble dynamics based model for cavitating flow simulations is extended to higher void fraction region for wider range of applications. The present bubble model is based on the so-called Rayleigh-Plesset equation that calculates a temporal bubble radius with the surrounding liquid pressure and is considered to be valid in an area below a certain void fraction. The solution algorithm is modified so that the Rayleigh-Plesset equation is no more solved once the bubble radius （or void fraction） reaches at a certain value till the liquid pressure recovers above the vapor pressure in order to overcome this problem. This procedure is expected to stabilize the numerical calculation. The results of simple two-dimensional flow field are presented compared with the existing bubble model.

关键词： cavitation model Computational Fluid Dynamics (CFD) cavitation flow Rayleigh-Plesset equation

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The Novel Current Control for Virtual Synchronous Generator

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Journal of Power and Energy Engineering 2020年第2期8卷 78-89页

作者： atsushi Umemura Rion Takahashi Junji tamura Department of Electrical and Electronic Engineering Kitami Institute of Technology Kitami Japan

In recent years, power generation using renewable energy sources has been developed as a solution to the global warming problem. Among these power generation methods, wind power generation is increasing. However, as the penetration level of wind power generation increases, the low inertia and lack of synchronous power characteristics of the penetrated power system can have a significant impact on the transient stability of the grid. The virtual synchronous generator provides the ability of virtual inertia and synchronous power to interconnected inverters. The interconnected inverter with the virtual synchronous generator ability uses, in general, PI control based current controller. This paper proposes a new current-control method and compares it with conventional methods. The proposed current control is a method that follows virtual synchronous generator model that changes every moment by solving the discrete-time linear quadratic optimal control problem for each sampling time interval. The new method follows the conventional method, and therefore the reactive power fluctuation can be suppressed and the interconnected inverter will be downsized.

关键词： Wind Energy Generation State Feedback Electric Current Control Linearization Techniques Discrete Time Model Following Control Virtual Synchronous Generator

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Stability Enhancement of Small-Scale Power Grid with Renewable Power Sources by Variable Speed Diesel Power Plant

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Journal of Power and Energy Engineering 2020年第3期8卷 1-17页

作者： Rion Takahashi atsushi Umemura Junji tamura Department of Earth Energy and Environmental Engineering Kitami Institute of Technology Kitami Japan

This paper proposes a power control method to improve a stability of a small-scale power grid with renewable energy sources. In an isolated small- scale power grid such as an island, diesel power plant is main power source which has an environmental burden and expensive running cost due to high priced fossil fuel. Thus, expanding installation of the renewable energy sources such as a wind power is strongly desirable. Such fluctuating energy sources, however, harm power quality of the small-scale power grid, and in addition, conventional power plant in the small-scale power grid cannot, in general, stabilize the grid system with such fluctuating power sources. In this study, Variable Speed Doubly-Fed Induction Generator (VS-DFIG) is proposed to be in-stalled at a diesel power plant instead of a conventional Fixed Speed Synchronous Generator (FS-SG), because quick control of a power balance in the small-scale power grid can be achieved by using the inertial energy of VS-DFIG. In addition, utilization of a Battery Energy Storage System (BESS) is also considered to assist cooperatively the VS-DFIG control. As a result of the simulation analysis by using the proposed method, it is verified that frequency fluctuations due to renewable energy source can be effectively reduced by quick power control of the VS-DFIG compared to the conventional FS-SG, and further control ability can be obtained by utilizing BESS. Moreover, the transient stability of a small-scale power grid during a grid fault can also be enhanced.

关键词： Small-Scale Power Grid Variable Speed Doubly-Fed Induction Generator (VS-DFIG) Diesel Power Plant Wind Power Battery Energy Storage System (BESS)

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