检索结果-南通市图书馆

Epidemiological impact of revoking mask-wearing recommendation on COVID-19 transmission in Tokyo,Japan

在线全文

学校读者我要写书评

暂无评论

Infectious Disease Modelling 2024年第4期9卷 1289-1300页

作者： Mayu nagata Yuta Okada Hiroshi Nishiura Kyoto University School of Public Health Yoshida-KonoeSakyoKyoto606-8601Japan

Despite the global implementation of COVID-19 mitigation measures,the disease continues to maintain *** mask wearing became one of the key measures for preventing the transmission of COVID-19 early in the pandemic period,many countries have relaxed the mandatory or recommended wearing of *** objective of the present study was to estimate the epidemiological impact of removing the mask-wearing recommendation in *** developed a model to assess the consequences of declining mask-wearing coverage after the government revoked its recommendation in February *** declining mask-wearing coverage was estimated using serial cross-sectional data,and a mathematical model was devised to determine the age-specific incidence of COVID-19 using the observed case count in Tokyo from week of October 3,2022 to October 30,*** explored model-based counterfactual scenarios to measure hypothetical situations in which the mask-wearing coverage decreases or increases relative to the observed *** results show that mask-wearing coverage declined from 97%to 69%by the week of October 30,2023,and that if the mask-wearing recommendation had continued,427 lives could have been saved in *** the mask-wearing coverage had declined to 25%of the observed level,the model suggests there might have been 1587 additional ***,revoking the mask-wearing recommendation had a substantial epidemiological *** future pandemics,our proposed approach could provide a realtime quantification of the effects of relaxing countermeasures.

关键词： COVID-19 Mask wearing recommendation Health policy Counterfactual Mathematical model

Impulse Turbine with 3D Guide Vanes for Wave Energy Conversion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2006年第1期15卷 27-30页

作者： Manabu TAKAO toshiaki SETOGUCHI Kenji KANEKO Shuichi nagata Department of Mechanical Engineering Matsue National College of Technology 14-4 Nishiikuma-cho Matsue-shi Shimane 690-8518 Japan Department of Mechanical Engineering Saga University 1 Honjo-machi Saga-shi Saga 840-8502 Japan Institute of Ocean Energy Saga University 1 Honjo-machi Saga-shi Saga 840-8502 Japan

In this study, in order to achieve further improvement of the performance of an impulse turbine with fixed guide vanes for wave energy conversion, the effect of guide vane shape on the performance was investigated by experiment. The investigation was performed by model testing under steady flow condition. As a result, it was found that the efficiency of the turbine with 3D guide vanes are slightly superior to that of the turbine with 2D guide vanes because of the increase of torque by means of 3D guide vane, though pressure drop across the turbine for the 3D case is slightly higher than that for the 2D case.

关键词： fluid machinery impulse turbine guide vane wave energy conversion.

Bell Operator Method to Classify Local Realistic Theories

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第3期27卷 29-32页

作者： Koji nagata Department of Agriculture and of Veterinary Medicine National Research Center for Protozoan Diseases University of Obihiro West 2-13 Inada Obihiro Hokkaido 080-8555 Japan

We review the historical fact of multipartite Bell inequalities with an arbitrary number of settings. An explicit local realistic model for the values of a correlation function, given in a two-setting Bell experiment （two-setting model）, works only for the specific set of settings in the given experiment, but cannot construct a local realistic model for the values of a correlation function, given in a continuous-infinite settings Bell experiment （infinite-setting model）, even though there exist two-setting models for all directions in space. Hence, the two-setting model does not have the property that the infinite-setting model has. Here, we show that an explicit two-setting model cannot construct a local realistic model for the values of a correlation function, given in an M-setting Bell experiment （M-setting model）, even though there exist two-setting models for the M measurement directions chosen in the given M-setting experiment. Hence, the two-setting model does not have the property that the M-setting model has.

关键词： Quantum information and quantum mechanics

Advances in traction methods for endoscopic submucosal dissection:What is the best traction method and traction direction?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2022年第1期28卷 1-22页

作者： Mitsuru nagata Department of Endoscopy Shonan Fujisawa Tokushukai HospitalKanagawa 251-0041Japan

Endoscopic submucosal dissection(ESD)has been developed as a treatment for superficial gastrointestinal neoplasms,which can achieve en bloc resection regardless of the lesion ***,ESD is technically difficult because endoscopists cannot bring their hand into the gastrointestinal tract,unlike surgeons in regular *** is difficult to obtain sufficient tension in the dissection plane and a good field of ***,ESD is associated with a long procedure time and a high risk of adverse events in comparison with endoscopic mucosal *** methods have been developed to provide sufficient tension for the dissection plane and a good field of vision during the ESD ***,traction direction is limited in most traction methods,resulting in insufficient effect in some *** traction direction is considered important,there have been few investigations of its *** the first half of this review,important traction methods are discussed,including traction *** second half,appropriate traction methods for each organ are *** important considerations for traction method,such as ability to adjust traction strength,interference between traction device and endoscope,and the need for specialized devices are also discussed.

关键词： Endoscopic submucosal dissection Traction method Countertraction Traction direction Vertical traction

Experimental Study on Load Characteristics in a Floating Type Pendulum Wave Energy Converter

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2014年第5期23卷 465-471页

作者： Tengen Murakami Yasutaka Imai Shuichi nagata Institute of Ocean Energy Saga University

A floating type pendulum wave energy converter(FPWEC) with a rotary vane pump as the power take-off system was proposed by Watabe et *** *** showed that this device had high energy conversion *** the previous research,the authors conducted 2D wave tank tests in regular waves to evaluate the generating efficiency of FPWEC with a power take-off system composed of pulleys,belts and a *** a result,the influence of the electrical load on the generating efficiency was ***,the load characteristics of FPWEC are pursued experimentally by using the servo motors to change the damping coefficient in this *** a later part of this paper,the motions of the model with the servo motors are compared with that of the case with the same power take-off system as the previous *** the above experiment,it may be concluded that the maximum primary conversion efficiency is achieved as high as 98%at the optimal load.

关键词： pendulum wave energy converter floating type load characteristics primary conversion efficiency

Adaptive Learning with Large Variability of Teaching Signals for Neural Networks and Its Application to Motion Control of an Industrial Robot

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2011年第1期8卷 54-61页

作者： Fusaomi nagata Keigo Watanabe Department of Mechanical Engineering Faculty of Engineering Tokyo University of Science Department of Intelligent Mechanical Systems Graduate School of Natural Science and Technology Okayama University

Recently, various control methods represented by proportional-integral-derivative （PID） control are used for robotic control. To cope with the requirements for high response and precision, advanced feedforward controllers such as gravity compensator, Coriolis/centrifugal force compensator and friction compensators have been built in the controller. Generally, it causes heavy computational load when calculating the compensating value within a short sampling period. In this paper, integrated recurrent neural networks are applied as a feedforward controller for PUMA560 manipulator. The feedforward controller works instead of gravity and Coriolis/centrifugal force compensators. In the learning process of the neural network by using back propagation algorithm, the learning coefficient and gain of sigmoid function are tuned intuitively and empirically according to teaching signals. The tuning is complicated because it is being conducted by trial and error. Especially, when the scale of teaching signal is large, the problem becomes crucial. To cope with the problem which concerns the learning performance, a simple and adaptive learning technique for large scale teaching signals is proposed. The learning techniques and control effectiveness are evaluated through simulations using the dynamic model of PUMA560 manipulator.

关键词： Neural networks large-scale teaching signal sigmoid function adaptive learning servo system PUMA560 manipulator trajectory following control nonlinear control.

Protein and non-protein sulfhydryls and disulfides in gastric mucosa and liver after gastrotoxic chemicals and sucralfate: Possible new targets of pharmacologic agents

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第14期13卷 2053-2060页

作者： Lajos Nagy Miki nagata Sandor Szabo Departments of Pathology Brigham & Women's Hospital Harvard Medical SchoolBostonMassachusetts 02115and Pathology and Laboratory Medicine ServiceDiagnostic & Molecular Medicine HCGVA Medical Center9901 East 7th St. Long BeachCA 90822United States Depts. of 3rd Internal Medicine and Family MedicineFaculty of MedicineUniversity of PecsH-7632 PecsHungary Departments of Pathology Brigham & Women's Hospital Harvard Medical SchoolBostonMassachusetts 02115and Pathology and Laboratory Medicine ServiceDiagnostic & Molecular Medicine HCGVA Medical Center9901 East 7th St. Long BeachCA 90822United States

AIM： To investigate the role of major non-protein and protein sulfhydryls and disulfides in chemically induced gastric hemorrhagic mucosal lesions （HML） and the mechanism of gastroprotective effect of sucralfate.METHODS： Rats were given 1 mL of 75% ethanol, 25%NaCl, 0.6 mol/L HCI, 0.2 mol/L NaOH or 1% ammonia solutions intragastrically （i.g.） and sacrificed 1, 3, 6 or 12 min later. Total （reduced and oxidized） glutathione （GSH ＋ GSSG）, glutathione disulfide （GSSG）, protein free sulfhydryls （PSH）, protein-glutathione mixed disulfides （PSSG） and protein cystine disulfides （PSSP） were measured in gastric mucosa and liver.RESULTS： Reduced glutathione （GSH） was depleted in the gastric mucosa after ethanol, HCI or NaCl exposure,while oxidized glutathione （GSSG） concentrations increased, except by HCI and NaOH exposure. Decreased levels of PSH after exposure to ethanol were observed,NaCl or NaOH while the total protein disulfides were increased. Ratios of reduced to oxidized glutathione or sulfhydrils to disulfides were decreased by all *** changes in thiol homeostasis were detected in the liver after i.g. abbreviation should be spelled out the first time here administration of ethanol. Sucralfate increased the concentrations of GSH and PSH and prevented the ethanol-induced changes in gastric mucosal thiol concentrations.CONCLUSION： Our modified methods are now suitable for direct measurements of major protein and nonprotein thiols/disulfides in the gastric mucosa or liver.A common element in the pathogenesis of chemically induced HML and in the mechanism of gastroprotective drugs seems to be the decreased ratios of reduced and oxidized glutathione as well as protein sulfhydryls and disulfides.

关键词： Non-protein and protein thiol Gastricmucosal injury Gastroprotection Sucralfate

Dynamics and geometry of developing planar jets based on the invariants of the velocity gradient tensor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2015年第6期27卷 894-906页

作者：吴楠楠 SAKAI Yasuhiko nagata Kouji ITO Yasumasa School of Electric Power Engineering China University of Mining and Technology Department of Mechanical Science and Engineering Nagoya University

Based on the direct numerical simulation （DNS）, the developing planar jets under different initial conditions, e.g., the con- ditions of the exit Reynolds number and the exit mean velocity profile, are investigated. We mainly focus on the characteristics of the invariants of the velocity gradient tensor, which provides insights into the evolution of the dynamics and the geometry of the planar jets along with the flow transition. The results show that the initial flow near the jet exit is strongly predominated by the dissipation over the enstrophy, the flow transition is accompanied by a severe rotation and straining of the flow elements, where the vortex structure evolves faster than the fluid element deformation, in the fully-developed state, the irrotational dissipation is dominant and the most probable geometry of the fluid elements should remain between the biaxial stretching and the axisymmetric stretching. In addition, with a small exit Re and a parabolic profile for the exit mean streamwise velocity, the decay of the mean flow field and the magnitude of the turbulent variables will be strengthened in the process of the flow transition, however, a large exit Re will promote the flow transition to the fully-developed state. The cross-impact between the exit Re and the exit mean velocity profile is also observed in the present study.

关键词： planar jet direct numerical simulation (DNS) velocity gradient tensor flow transition joint probability density function(joint pdf)

Floating Type Ocean Wave Power Station Equipped with Hydroelectric Unit

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2013年第5期22卷 467-471页

作者： Shun Okamoto toshiaki Kanemoto Toshihiko Umekage Kyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 Japan

The authors have invented the unique ocean wave power station,which is composed of the floating type platform with a pair of the floats lining up at the interval of one wave pitch and the counter-rotating type wave power unit,its runners are submerged in the seawater at the middle position of the *** profiles make the flow velocity at the runner is twice faster than that of the traditional fixed/caisson type OWC,on the ideal flow ***,the runners counter-rotate the inner and the outer armatures of the peculiar generator,respectively,and the relative rotational speed is also twice faster than the speed of the single runner/*** characteristics make the runner diameter large,namely the output higher,as requested,because the torque of the power unit never act on the floating type *** the preliminary reseach,this paper verifies to get the power using a Wells type single runner installed in the model *** runner takes the output which is affected by the oscillating amplitude of the platform,the rotational speed and the inertia force of the runner,etc.

关键词： Renewable energy Ocean wave Float Platform Counter-rotation Power unit