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Numerical study on tidal currents and seawater exchange in the Benoa Bay, Bali, Indonesia

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Acta Oceanologica Sinica 2014年第3期33卷 90-100页

作者： HENDRAWAN I Gede asai Koji Department of Marine Sciences Faculty of Marine Sciences and Fisheries Udayana University Department of Civil and Environmental Engineering Yamaguchi University

A three-dimensional （3-D） finite volume coastal ocean model （FVCOM） was used for the study of water cir culation and seawater exchange in the Benoa Bay, Bali Island. The M2 tidal component was forced in open boundary and discharge from six rivers was included in the numerical calculation. The M2 tidal elevation produced by the FVCOM has a good agreement with the observation data. The M2 tidal current is also suc cessfully calculated under the ebb tide and flood tide conditions. The non-linear M2 tidal residual current was produced by the coastline geometry, especially surrounding the narrow strait between the Serangan Is- land and the Benoa Peninsula. The tidal residual current also generated two small eddies within the bay and one small eddy in the bay mouth. The salinity distribution influenced by river discharge could be success- fully calculated, where the numerical calculation and the observation results have a good correlation （r2） of 0.75. Finally in order to examine the seawater exchange in the Benoa Bay, the Lagrangian particle tracking method and calculation of residence time are applied. The mechanism of particle transport to the flushing of seawater is depicted clearly by both methods.

关键词： FVCOM M2 tidal current M2 residual current salinity seawater exchange

Assessing the efficacy of health countermeasures on arrival time of infectious diseases

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Infectious Disease Modelling 2023年第2期8卷 603-616页

作者： Yusuke asai Disease Control and Prevention Center National Center for Global Health and Medicine1-21-1 ToyamaShinjuku-kuTokyo162-8655Japan

Public health measures to control the international spread of infectious diseases include strengthening quarantines and sealing *** these measures are effective in delaying the importation of infectious diseases,they also have a significant economic impact by stopping the flow of people and *** arrival time of infectious diseases is often used to assess quarantine *** the arrival time is highly dependent on the number of infected cases in the endemic country,direct comparisons have not yet been ***,this study derives an explicit relationship between the number of infected cases and arrival *** behavior is stochastic,and deterministic models are not always *** this study,random differential equations,which are differential equations with stochastic processes,were used to describe the dynamics of infection in an endemic ***,the flow of travelers from the endemic country was described in terms of survival time,and the arrival time in each country was calculated.A scenario in which PCR kits were distributed between endemic and diseasefree countries was also considered,and the impact of different distribution rates on arrival time was *** simulation results showed that increasing the distribution of PCR kits in the endemic country was more effective in delaying arrival times than using PCR kits in quarantine in disease-free *** was also found that increasing the proportion of identified infected persons in the endemic country,leading to isolation,was more important and effective in delaying arrival times than increasing the number of PCR tests.

关键词： Epidemic model Arrival time Health countermeasures Quarantine Random ODE

Simulation of Water-Soil-Structure Interactions Using Incompressible Smoothed Particle Hydrodynamics

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Computers, Materials & Continua 2020年第10期65卷 205-224页

作者： Abdelraheem M.Aly Mitsuteru asai Ehab Mahmoud Mohamed Department of Mathematics College of ScienceKing Khalid UniversityAbha62529Saudi Arabia Department of Mathematics Faculty of ScienceSouth Valley UniversityQena83523Egypt Civil Engineering Department Kyushu UniversityFukuoka819-0395Japan Electrical Engineering Department College of EngineeringPrince Sattam Bin Abdulaziz UniversityWadi Addwasir11991Saudi Arabia Electrical Engineering Department Faculty of EngineeringAswan UniversityAswan81542Egypt

In the present work,an incompressible smoothed particle hydrodynamic(SPH)method is introduced to simulate water-soil-structure *** the current calculation,the water is modelled as a Newtonian *** soil is modelled in two different *** the first case,the granular material is considered as a fluid where a Bingham type constitutive model is proposed based on Mohr-Coulomb yield-stress criterion,and the viscosity is derived from the cohesion and friction *** addition,the fictitious suspension layers between water and soil depending on the concentration of soil are *** the second case,Hooke’s law introduces elastic *** ISPH,the pressure is evaluated by solving the pressure Poisson equation using a semi-implicit algorithm based on the projection method and an eddy viscosity for water is modelled by a large eddy simulation with the Smagorinsky *** the proposed ISPH method,the pressure is stabilized to simulate the multiphase flow between soil and *** experiments for water-soil suspension flow of Louvain erosional dam break with flat soil foundation,is simulated and validated using 3D-ISPH *** between water-soil interactions with different solid structures are *** results revealed that,the suspension layers with the Bingham model of soil gives more accurate results in the experiment as compared to the case of the Bingham model without suspension *** addition,the elastic soil model by the Hooke’s law can simulate soil hump accurately as compared to the Bingham *** the simulations,avoiding erosion behind the structure for preventing the structure break during flood are investigated by using an extended structure or a wedge structure.

关键词： Bingham model ISPH method rigid body water-soil interactions

CNN-based segmentation frameworks for structural component and earthquake damage determinations using UAV images

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Earthquake Engineering and Engineering Vibration 2023年第2期22卷 359-369页

作者： Taisei Saida Muhammad Rashid Yudai Nemoto Shota Tsukamoto Takehiko asai Mayuko Nishio Graduate School of Science and Technology University of TsukubaTsukubaJapan Faculty of Engineering Information and SystemsUniversity of TsukubaTsukubaJapan

Buildings undergo various kinds of structural damage during earthquakes,and damage detection and functional assessment of these structures in the aftermath of the events have been challenging *** these circumstances,computer vision techniques offer a promising solution by automating the inspection *** study presents an effective methodology for automatic structural components and damage detection using unmanned aerial vehicle(UAV)images of damaged *** types of neural network architectures are considered for appropriate feature extractions in different task *** feature pyramid network(FPN)is employed for crack,spall,rebar,and component damage segmentation,while the UNet++network is utilized for the damage *** network training and validation,a total of 3805 original images of size 1920×1080 pixels are processed by the proposed method and reduced the image *** the FPN,the achieved highest intersection over unions(IoUs)were 0.59,0.93,0.42,and 0.99 for crack,spall,rebar,and components,*** predicted labels were found in close agreement with the ***,the UNet++recognized the semantic information and damage state with an IoU of *** demonstrated the applicability of the proposed method for automated post-earthquake building inspection process accurately without information loss from the original images.

关键词： computer vision semantic segmentation component segmentation damage evaluation FPN UNet++

The interanual rainfall variability in Indonesia corresponding to El Ni?o Southern Oscillation and Indian Ocean Dipole

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Acta Oceanologica Sinica 2019年第7期38卷 57-66页

作者： I Gede Hendrawan Koji asai Andhita Triwahyuni Diah Valentina Lestari Department of Marine Science Udayana UniversityBadungBali 80361Indonesia Graduate School Science and Engineering Yamaguchi UniversityYamaguchi 755-8611Japan Department of Environmental Engineering Faculty of EngineeringMahasaraswati UniversityDenpasarBali 80236Indonesia Center for Remote Sensing and Ocean Sciences Udayana UniversityBadungBali 80361Indonesia

The Impact of the Indian Ocean Dipole(IOD)and the El Nino Southern Oscillation(ENSO)event for Indonesian rainfall has been investigated for the period from 1950 to ***-annual change of IOD and ENSO indices are used to investigate their relationship with Indonesian *** using the wavelet transform method,we found a positive significant correlation between IOD and Indonesian rainfall on the time scale of nearly 2.5–4 ***,the positive significant correlation between ENSO(sea surface temperature anomaly at Nino3.4 area indices)and Indonesian rainfall exists for shorter than 2 years and between 5.5 to 6.5-year time scales.

关键词： IOD ENSO Indonesian rainfall wavelet

Prediction of Acoustic Absorption Performance of a Perforated Plate with Air Jets

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Journal of Thermal Science 2017年第4期26卷 378-384页

作者： Hiromitsu Hamakawa Masanori Miyazaki Yuta asai Eru Kurihara Eiichi Nishida Hidechito Hayashi Department of Mechanical Engineering Oita University700 DannoharuOita 870-1192Japan Graduate Student Oita University700 DannoharuOita 870-1192Japan Department of Mechanical Systems Engineering Shonan Institute of Technology1-1-25 Tsujido-NishikaiganFuji-sawaKanagawa 251-8511Japan Department of Mechanical Engineering Nagasaki University1-14 Bunkyo machiNagasaki852-8521Japan

The present study focuses on the prediction of acoustic absorption performance of a perforated plate with air jets by theoretical calculations. In addition, we experimentally measured the flow rate, internal pressure, acoustic pressure, and transfer function using an acoustic impedance tube. The normal incidence absorption coefficient was calculated from the measured transfer function using transfer function methods. We investigated the influences of background air space, flow velocity, thickness, aperture rate, and aperture diameter of a perforated plate on the acoustic absorption characteristics. The frequency characteristics of the acoustic absorption coefficient showed a maximum value at a local frequency. As the background air space increased, the peak frequency of acoustic absorption characteristics decreased. As the flow velocity passing through the apertures increased, the peak level of the acoustic absorption coefficient also increased. The theoretical results agreed well with the experimental ones qualitatively.

关键词： acoustic absorption perforated plate theoretical prediction acoustic impedance tube air jets

EFFECT OF INTERMITTENT HIGH FREQUENCY MAGNETIC FIELD ON INITIAL SOLIDIFICATION IN CONTINUOUS CASTING

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Acta Metallurgica Sinica(English Letters) 1997年第2期10卷 151-156页

作者： Li, T.J. Sassa, K. asai, S. Dalian Univ of Technology Dalian China

Contacting state between molten metal and a mold and initial solidification process of continuously cast metals can be controlled by imposing an intermittent magnetic *** this study, effect of the intermittent magnetic field on the initial solidification ofcontinuoasly cast metals was investigated by measuring the temperature distribution in the melt pool and the initial solidification starting position of shells. It was found that under the condition with intermittent magnetic field, the melt near meniscns is in slow cooling state, the initial solidification starting position descends, initial solidification shell thickens and the liquid-solid interface becomes smooth.

关键词： continuous casting initial solidification of metal surface quality of cast metal electromagnetic field

鞘氨醇-1-磷酸受体调节剂治疗溃疡性结肠炎的研究进展

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中华炎性肠病杂志(中英文) 2024年第5期08卷 403-406页

作者：叶尔森·阿赛高鸿亮新疆医科大学第一附属医院消化病二科乌鲁木齐

溃疡性结肠炎(UC)是一种慢性复发性炎性肠病, 涉及免疫反应失调和慢性黏膜炎症。中重度UC的主要治疗方法包括生物制剂和小分子药物。目前的研究证明需要开发针对新靶点的药物, 并且将不良事件的风险降至最低。奥扎莫德是一种选择性鞘氨... 详细信息

溃疡性结肠炎(UC)是一种慢性复发性炎性肠病, 涉及免疫反应失调和慢性黏膜炎症。中重度UC的主要治疗方法包括生物制剂和小分子药物。目前的研究证明需要开发针对新靶点的药物, 并且将不良事件的风险降至最低。奥扎莫德是一种选择性鞘氨醇-1-磷酸受体(S1PR)调节剂, 主要作用于S1PR1和S1PR5来缓解UC症状, 现已批准用于治疗中重度UC。本文就鞘氨醇-1-磷酸(S1P)信号转导通路、不同S1PR调节剂治疗UC的研究进展进行综述。

关键词：溃疡性结肠炎鞘氨醇-1-磷酸鞘氨醇-1-磷酸受体调节剂奥扎莫德机制治疗

Luminescence properties of Gd2Si2O7：Ce and Gd2Si2O7：La,Ce under vacuum ultraviolet irradiation

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Journal of Rare Earths 2016年第8期34卷 782-785页

作者： M.Koshimizu T.Yanagida Y.Fujimoto K.asai Department of Applied Chemistry Graduate School of Engineering Tohoku University 6-6-07 Aoba Aramaof Aoba-ku Sendai 980-8579 Japan Graduate School of Materials Science Nara Institute of Science and Technology 8916-5 Takayama-Cho Ikoma Nara 630-0192 Japan

The luminescence properties of Ce- or Ce and La-doped gadolinium pyrosilicate （Gd2Si2OT, GPS） were characterized using vacuum ultraviolet （VUV） excitation light. A prominent emission band was observed in the luminescence spectra with excitation at 60 nm and ascribed to 5d-4f transition of Ce3＋. Because the excitation wavelength of 60 nm corresponded to the excitation in the host matrix, this result indicated that the excitation energy transfer occurred from the host matrix to Ce3＋ ions. On the basis of the rise in the luminescence time profiles with excitation at 60 nm, the energy transfer occurred within 2 ns, which was much shorter than that of Ce-doped Gd2SiO2. For Ce-doped GPS, the decay rate was slower for the host excitation than that for direct excitation of Ce3＋. In contrast, for Ce and La-doped GPS, no significant difference was observed for the host excitation and direct excitation of Ce3＋. This result indicated that the energy transfer from the host to Ce3＋ ions led to a different radiative decay process, and that La doping had an effect on the energy transfer and decay process.

关键词： energy transfer scintillation vacuum ultraviolet rare earths