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Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization
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作者 Huaizhi Zong Junhui Zhang +6 位作者 Lei Jiang Kun Zhang Jun Shen Zhenyu Lu Ke Wang Yanli Wang Bing Xu 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第1期1-13,共13页
Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped robots.Among various quadruped robots,hydraulically driven quadr... Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped robots.Among various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large payloads.As the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight design.Inspired by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an LLU.We propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston rod.In addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the LLU.The mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah muscle.The mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency. 展开更多
关键词 Additive manufacturing Bionic lightweight design Limb leg unit Quadruped robot Trajectory tracking
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A Deep Learning-Based Teaching Design for High School Geography Units:Taking the Example of Landforms of the Humanistic Education Edition
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作者 Xiaojie Yuan Chenguang Zhang +3 位作者 Jiajia Li Jiqiang Niu Xiumei Li Xingjun Shi 《Journal of Contemporary Educational Research》 2024年第2期176-182,共7页
The traditional teaching methods of one-way cultivation of students can no longer meet the requirements of talent cultivation at this stage.The issue of how to promote students from passive acceptance to the independe... The traditional teaching methods of one-way cultivation of students can no longer meet the requirements of talent cultivation at this stage.The issue of how to promote students from passive acceptance to the independent cognitive understanding stage(i.e.deep learning)has become the focus of geography teaching.Therefore,under the guidance of deep learning theory,this paper takes the“landforms”knowledge unit of the Humanistic Education Edition as an example,improves the classroom teaching means through the unit teaching mode,reconstructs the“landforms”teaching unit,and explores the specific teaching of high school geography unit based on deep learning.This study provides a good example and guidelines for high school geography teaching and learning. 展开更多
关键词 Deep learning unit teaching Geography education Case design High school education
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Research on an Intelligent Decision Support System for a Conceptual Innovation Design of Pumping Units Based on TRIZ 被引量:1
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作者 Zhang Peng He Chuan Guan Hongxiang Gai Feng Qi Bin 《Petroleum Science》 SCIE CAS CSCD 2006年第1期85-91,共7页
Attention is concentrated on how to perform the innovative design during the process of pumping unit conceptual design, and how to enhance design efficiency and inspire creativity. Aiming at the shortages of conceptua... Attention is concentrated on how to perform the innovative design during the process of pumping unit conceptual design, and how to enhance design efficiency and inspire creativity. Aiming at the shortages of conceptual design, introducing the theory of inventive problem solving (TRIZ) into the mechanical product design for producing innovative ideas, and using the advanced computer-aided technique, the intelligent decision support system (IDSS) based on TRIZ (TRIZ-IDSS) has been constructed. The construction method, system structure, conceptual production, decisionmaking and evaluation of the problem solving subsystem are discussed. The innovative conceptual design of pumping units indicates that the system can help the engineers open up a new space of thinking, overcome the thinking inertia, and put forward innovative design concepts. This system also can offer the scientific instructions for the innovative design of mechanical products. 展开更多
关键词 Pumping units innovative conceptual design TRIZ intelligent decision support system
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A Survey Study of Kindergarten Teachers’Use of ChatGPT to Support Instructional Design
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作者 Wanlin Chen Yali Wang +1 位作者 Lailin Hu Gang Yang 《教育技术与创新》 2024年第3期47-55,共9页
With the rapid development of information technology,Artificial Intelligence(AI)is gradually applied to a wide range of fields,especially the powerful ability of ChatGPT to bring infinite possibilities for education,b... With the rapid development of information technology,Artificial Intelligence(AI)is gradually applied to a wide range of fields,especially the powerful ability of ChatGPT to bring infinite possibilities for education,but teachers’attitudes toward using it are not yet clear.The study investigates the use of ChatGPT by kindergarten teachers to support instructional design using questionnaires and interviews to explore the attitudes and perceptions of kindergarten teachers toward its use.The results indicate that kindergarten teachers hold positive preferences for technology acceptance,perceived self-efficacy,and learning attitudes toward using ChatGPT for instructional design.Meanwhile,the study argues that more research is needed in the future to focus on how kindergarten teachers can aptly use ChatGPT to improve the quality of instruction in realistic instructionenvironments. 展开更多
关键词 Kindergarten Teachers ChatGPT Instructional design survey Study STEM
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Design of Distorted Wave Protection Armor Units
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作者 Lou Hongen Senior Engineer, Nanjing Hydraulic Research Institute, 210029, Nanjing 《China Ocean Engineering》 SCIE EI 1992年第4期445-454,共10页
In consideration of the global optimization for engineering projects, a group of calculation formulas have been derived by means of theoretical derivation and model tests. On this basis, a design procedure for the dis... In consideration of the global optimization for engineering projects, a group of calculation formulas have been derived by means of theoretical derivation and model tests. On this basis, a design procedure for the distorted units is proposed, by means of which the distorted units of an anology shape and an identical porosity ratio with the original units can be obtained after conducting a distorted enlargement and a normal contraction. The stability waveheight and stability factor of the distorted unit can be calculated with the enlargement factor, a, of the horizontal dimension of the distorted unit, or with the contraction scale, A , of the contracted distorted unit. As a result, the stability of the armor unit can be significantly improved without increasing the quantity of concrete. For the same wave met by the original units, the thickness of placement of the contracted distorted unit can be obviously reduced, thus, a large quantity of concrete can be saved, consequently, economic benefit can be achieved. 展开更多
关键词 armor unit breakwater design STRUCTURE wave protection
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The design and practice of giant hydro turbine generating units of Three Gorges Project
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作者 Shao Jianxiong Liu Jingwang Yuan Dafu 《Engineering Sciences》 EI 2011年第3期88-95,共8页
The main technical problems that should be considered in the design of hydro-turbine generating units of Three Gorges Project (TGP) are analyzed;the key technical researches performed are summarized,and the parameters... The main technical problems that should be considered in the design of hydro-turbine generating units of Three Gorges Project (TGP) are analyzed;the key technical researches performed are summarized,and the parameters of hydro-turbine generating units are optimized through the study on key technical problems.The unit operation indicates that the performance of the hydro-turbine generating units is excellent,and the units can operate in a safe,stable and highly efficient mode for a long term.Therefore,it is verified effectively that the general technical design of units is scientific and rational. 展开更多
关键词 Three Gorges Project (TGP) 700 MW hydro-turbine generating unit unit capacity design and research operation stability practice
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The Conceptual Design Method for a Pumping Unit Based on QFD and TRIZ 被引量:4
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作者 Zhang Peng Gai Feng Guan Hongxiang Li Ping 《Petroleum Science》 SCIE CAS CSCD 2005年第4期77-82,共6页
Quality function deployment (QFD) is a quality system, that can help to design novel products that meet customers' needs. Theory of inventive problem solving (TRIZ) is a very powerful tool in helping to solve dif... Quality function deployment (QFD) is a quality system, that can help to design novel products that meet customers' needs. Theory of inventive problem solving (TRIZ) is a very powerful tool in helping to solve difficult technical problems encountered in the design process. Introducing QFD and TRIZ into the conceptual design of the pumping unit combines advantages of these two theories, therefore meeting different demands of different users. It can tell us “What should we do it” with QFD and “How should we do it” with TRIZ. The conceptual design method, which is based on QFD and TRIZ, is introduced andused to analyze and evaluate the conceptual design project of a pumping unit. 展开更多
关键词 Pumping unit quality function deployment (QFD) theory of inventive problem solving (TRIZ) conceptual design method
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基于Design-Expert的电链锯锯齿结构参数优化
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作者 刘九庆 张天翼 +1 位作者 金攀 朱斌海 《森林工程》 北大核心 2024年第2期142-150,共9页
为提高电链锯的锯切效率,对电链锯锯齿的齿形结构参数进行研究,以单位锯切功为电链锯锯切效率的衡量指标,通过对电链锯锯切过程的仿真研究,得出不同结构锯齿的单位锯切功。以电链锯锯齿中的外形前角、侧刃楔角和顶刃楔角等结构参数作为... 为提高电链锯的锯切效率,对电链锯锯齿的齿形结构参数进行研究,以单位锯切功为电链锯锯切效率的衡量指标,通过对电链锯锯切过程的仿真研究,得出不同结构锯齿的单位锯切功。以电链锯锯齿中的外形前角、侧刃楔角和顶刃楔角等结构参数作为影响因子,采用Box-Benhnken中心组合试验方法设计多因素正交试验,使用Design-expert软件进行数据分析得出最优齿形结构参数组合。研究结果表明,所选取的齿形结构参数对单位锯切功影响程度由大到小顺序依次为外形前角、侧刃楔角、顶刃楔角,并获得最优齿形结构参数组合,外形前角为10.92°、侧刃楔角为45.7°、顶刃楔角为45.41°。 展开更多
关键词 电链锯 锯切效率 齿形结构参数 design-expert 单位锯切功
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MicroGrid Designer:user-friendly design,operation and control assist tools for resilient microgrid and autonomous community 被引量:2
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作者 Ryuichi Yokoyama Yicheng Zhou 《Global Energy Interconnection》 EI CAS CSCD 2022年第3期249-258,共10页
During this decade,many countries have experienced natural and accidental disasters,such as typhoons,floods,earthquakes,and nuclear plant accidents,causing catastrophic damage to infrastructures.Since the end of 2019,... During this decade,many countries have experienced natural and accidental disasters,such as typhoons,floods,earthquakes,and nuclear plant accidents,causing catastrophic damage to infrastructures.Since the end of 2019,all countries of the world are struggling with the COVID-19 and pursuing countermeasures,including inoculation of vaccine,and changes in our lifestyle and social structures.All these experiences have made the residents in the affected regions keenly aware of the need for new infrastructures that are resilient and autonomous,so that vital lifelines are secured during calamities.A paradigm shift has been taking place toward reorganizing the energy social service management in many countries,including Japan,by effective use of sustainable energy and new supply schemes.However,such new power sources and supply schemes would affect the power grid through intermittency of power output and the deterioration of power quality and service.Therefore,new social infrastructures and novel management systems to supply energy and social service will be required.In this paper,user-friendly design,operation and control assist tools for resilient microgrids and autonomous communities are proposed and applied to the standard microgrid to verify its effectiveness and performance. 展开更多
关键词 MICROGRID Autonomous community Grid design and analysis RESILIENCE unit commitment Economic load dispatch Load frequency control Dynamic power flow Energy management system
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Mechanical and Acoustic Performance Test of New Designed Metal Noise Barrier Unit Plate with No Riveted Connection 被引量:1
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作者 LUAN Haoxiang WU Jin +3 位作者 PAN Jiayu ZHU Wanxu ZHOU Hongmei PENG Hanze 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第2期343-352,共10页
The modern transportation system is increasingly developed during recent years.It is an effective solution to set the noise barriers to reduce the traffic noise pollution caused by different kinds of transportation sy... The modern transportation system is increasingly developed during recent years.It is an effective solution to set the noise barriers to reduce the traffic noise pollution caused by different kinds of transportation systems.Many deficiencies on concrete noise barriers and metal noise barriers with rivet structure can be eliminated by a new kind of noise barrier with no-riveted structure.The mechanical performance examination and acoustic performance test are conducted on the new-designed noise barrier with no-riveted structure.The results indicate that the maximum stress is 1.74 MPa and the maximum deformation is 1.04 mm with load acting on the unit plate.The noise reduction coefficient of this kind of no-riveted noise barrier unit plate is 0.75 and its noise insulation is 40 dB,which were conform to or superior to the standard requirements.Therefore,this new designed noise barrier meets the field application requirements of mechanical and acoustic performance,which demonstrates the noise barriers can be widely promoted. 展开更多
关键词 noise barrier unit plate no-riveted connection structure design mechanical performance acoustic performance
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SIMULATION IN THERMAL DESIGN FOR ELECTRONIC CONTROL UNIT OF ELECTRONIC UNIT PUMP 被引量:1
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作者 XU Quankui ZHU Keqing ZHUO Bin MAO Xiaojian WANG Junxi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第5期1-7,共7页
The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit (ECU) design. By means of circuit simulation... The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit (ECU) design. By means of circuit simulation, the thermal design of ECU for electronic unit pump (EUP) fuel system is applied. The power dissipation model of each power component in the ECU is created and simulated. According to the analyses of simulation results, the factors which affect the power dissipation of components are analyzed. Then the ways for reducing the power dissipation of power components are carried out. The power dissipation of power components at different engine state is calculated and analyzed. The maximal power dissipation of each power component in all possible engine state is also carried out based on these simulations. A cooling system is designed based on these studies. The tests show that the maximum total power dissipation of ECU drops from 43.2 W to 33.84 W after these simulations and optimizations. These applications of simulations in thermal design of ECU can greatly increase the quality of the design, save the design cost and shorten design time 展开更多
关键词 Diesel engine Electronic unit pump Electronic control unit Circuit simulation Thermal design
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Critical care practice in India:Results of the intensive care unit need assessment survey(ININ2018) 被引量:1
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作者 Rahul Kashyap Kirtivardhan Vashistha +15 位作者 Chetan Saini Taru Dutt Dileep Raman Vikas Bansal Harpreet Singh Geeta Bhandari Nagarajan Ramakrishnan Harshit Seth Divya Sharma Premkumar Seshadri Mradul Kumar Daga Mohan Gurjar Yash Javeri Salim Surani Joseph Varon 《World Journal of Critical Care Medicine》 2020年第2期31-42,共12页
BACKGROUND A diverse country like India may have variable intensive care units(ICUs)practices at state and city levels.AIM To gain insight into clinical services and processes of care in ICUs in India,this would help ... BACKGROUND A diverse country like India may have variable intensive care units(ICUs)practices at state and city levels.AIM To gain insight into clinical services and processes of care in ICUs in India,this would help plan for potential educational and quality improvement interventions.METHODS The Indian ICU needs assessment research group of diverse-skilled individuals was formed.A pan-India survey"Indian National ICU Needs"assessment(ININ 2018-I)was designed on google forms and deployed from July 23rd-August 25th,2018.The survey was sent to select distribution lists of ICU providers from all 29 states and 7 union territories(UTs).In addition to emails and phone calls,social medial applications-WhatsApp™,Facebook™and LinkedIn™were used to remind and motivate providers.By completing and submitting the survey,providers gave their consent for research purposes.This study was deemed eligible for category-2 Institutional Review Board exempt status.RESULTS There were total 134 adult/adult-pediatrics ICU responses from 24(83%out of 29)states,and two(28%out of 7)UTs in 61 cities.They had median(IQR)16(10-25)beds and most,were mixed medical-surgical,111(83%),with 108(81%)being adult-only ICUs.Representative responders were young,median(IQR),38(32-44)years age and majority,n=108(81%)were males.The consultants were,n=101(75%).A total of 77(57%)reported to have 24 h in-house intensivist.A total of 68(51%)ICUs reported to have either 2:1 or 2≥:1 patient:nurse ratio.More than 80%of the ICUs were open,and mixed type.Protocols followed regularly by the ICUs included sepsis care,ventilator-associated pneumonia(83%each);nutrition(82%),deep vein thrombosis prophylaxis(87%),stress ulcer prophylaxis(88%)and glycemic control(92%).Digital infrastructure was found to be poor,with only 46%of the ICUs reporting high-speed internet availability.CONCLUSION In this large,national,semi-structured,need-assessment survey,the need for improved manpower including;in-house intensivists,and decreasing patient-tonurse ratios was evident.Sepsis was the most common diagnosis and quality and research initiatives to decrease sepsis mortality and ICU length of stay could be prioritized.Additionally,subsequent surveys can focus on digital infrastructure for standardized care and efficient resource utilization and enhancing compliance with existing protocols. 展开更多
关键词 Intensive care unit Critical care INDIA survey Intensive care unit survey Intensive care unit needs
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Characteristics and experience in the electrical design of the first domestically-integrated large-scale air separation unit
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作者 GONG Zhaoliang 《Baosteel Technical Research》 CAS 2009年第3期18-22,共5页
The first domestically-integrated large-scale air separation unit (ASU) with a capacity of 60 000 m^3/h was successfully built and put into operation at Baosteel. Compared with the electrical design of the imported ... The first domestically-integrated large-scale air separation unit (ASU) with a capacity of 60 000 m^3/h was successfully built and put into operation at Baosteel. Compared with the electrical design of the imported equipment of the same type,this ASU has an electrical protection interlink that is independent from the distribution control system (DCS). With the design idea of simplicity, the ASU features a simplified configuration and an audio alarm system for electrical failures. It helps reduce the failure rate of the electrical equipment and detect failures quickly and accurately. It will effectively enhance safe and stabilized production. The ASU can not only reduce the cost of investment, but also ensure a smooth and stable running of the whole electrical equipment. This study focuses on the experience and understanding of the unit design and commissioning. 展开更多
关键词 air separation unit LOCALIZATION electrical design characteristics
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Design of 8.0Mt/a Atmospheric and Vacuum Distillation Unit
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作者 Li Hejie(Luoyang Petrochemical Engineering Company ,Luoyang 471003) 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2003年第1期35-41,共7页
The design features of 8 Mt/a atmospheric and vacuum distillation unit (Ⅲ) in Zhenhai Refiningand Chemical Company are presented and various process schemes are compared. Production practice hasproved that the main p... The design features of 8 Mt/a atmospheric and vacuum distillation unit (Ⅲ) in Zhenhai Refiningand Chemical Company are presented and various process schemes are compared. Production practice hasproved that the main process design is advanced and reasonable and the process parameters basicallyreached design requirements. 展开更多
关键词 distillation unit atmospheric and vacuum distillation unit design revamping large-scale process unit imported crude
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Identification and evolution of tectonic units in the Philippine Sea Plate
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作者 Tian-yu Zhang Pan-feng Li +4 位作者 Lu-ning Shang Jing-yi Cong Xia Li Yong-jian Yao Yong Zhang 《China Geology》 2022年第1期96-109,共14页
The Philippine Sea Plate is located at the convergence zone of the Eurasian Plate,the Pacific Plate,and the Indo-Australian Plate.This paper divides the Philippine Sea Plate into two second-order tectonic units and ei... The Philippine Sea Plate is located at the convergence zone of the Eurasian Plate,the Pacific Plate,and the Indo-Australian Plate.This paper divides the Philippine Sea Plate into two second-order tectonic units and eight third-order tectonic units by summarizing the marine geological,geophysical,and submarine geomorphological data of the Philippine Sea Plate collected for years and referring to the seafloor spreading theory and the trench-arc-basin system.The two second-order tectonic units are the West Philippine Sea block and the Izu-Bonin-Mariana arc-basin system.The former includes the West Philippine Basin,the Huatung Basin,the Daito Basin,and the Palau Basin,while the latter consists of the Kyushu-Palau Ridge,the Shikoku-Parece Vela Basin,the Izu-Bonin Arc,and the Mariana Arc.Furthermore,this study concludes that the Philippine Sea Plate has undergone three stages of tectonic evolution,namely the early stage of the evolution of marginal basins with Cretaceous basement(Early Cretaceous),the middle stage of the spreading of the West Philippine Basin(Eocene),and the late stage of the subduction of the Izu-Bonin-Mariana arc-basin system(Oligocene-present).The Kyushu-Palau Ridge is a window to discover the tectonic evolution of the Philippine Sea Plate due to its unique geographical location. 展开更多
关键词 Philippine Sea Plate Tectonic unit Tectonic evolution Trench-arc-basin system Kyushu-Palau Ridge Izu-Bonin-Mariana arc Marine scientific survey
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A new design of measuring marine primary productivity to support eco-geological survey
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作者 Shao-feng Pei Ya-xuan Zhu +4 位作者 Si-yuan Ye Hong-ming Yuan Ruo-shun Guo Li-xin Pei Edward A. Laws 《China Geology》 2019年第1期112-113,共2页
1.Objective To measure marine primary productivity as precisely as possible and solve the issues existed in current devices, a new design based on the classical oxygen light-dark bottle methodology (Staehr PA et al., ... 1.Objective To measure marine primary productivity as precisely as possible and solve the issues existed in current devices, a new design based on the classical oxygen light-dark bottle methodology (Staehr PA et al., 2010) and integrated with new compact models of ‘simulated’ in situ (SIS) incubations was developed in this study, and it worked well in efficiently supporting our geological survey. 展开更多
关键词 design PRODUCTIVITY survey
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Toward Estimating the Variance in Acoustic Surveys Based on Sampling Design
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作者 Magnar Aksland 《Open Journal of Marine Science》 2011年第1期1-17,共17页
This paper develops a sampling method to estimate the integral of a function of the area with a strategy to cover the area with parallel lines of observation. This sampling strategy is special in that lines very close... This paper develops a sampling method to estimate the integral of a function of the area with a strategy to cover the area with parallel lines of observation. This sampling strategy is special in that lines very close to each other are selected much more seldom than under a uniformly random design for the positions of the parallel lines. It is also special in that the positions of some of the lines are deterministic. Two different variance estimators are derived and investigated by sampling different man made signal functions. They show different properties in that the estimator that estimate the biggest variance gives an error interval that, in some situations, may be more than ten times the error interval computed from the other estimator. It is also obvious that the second estimator underestimates the variance. The author has not succeeded to derive an expression for the expectation of this estimator. This work is motivated towards finding the variance of acoustic abundance estimates. 展开更多
关键词 ACOUSTIC ABUNDANCE ESTIMATION LINE surveys Sampling design Sampling in the Area Variance ESTIMATION
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Optimum Structural Design of a Chain-Driving Pumping Unit
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作者 Zhang Ailin and Liu Yang(Doctors,Qinhuangdao Branch of Daqing Petroleum Institute) 《China Oil & Gas》 CAS 1994年第4期45-47,共3页
In this paper the pumping unit of type QLCJ14-6 is studied.Through the belt driving unit,the mo-tor drives the driving sprocket in which the rotation rate has been reduced by the reduction ge arbox.The locus chain mov... In this paper the pumping unit of type QLCJ14-6 is studied.Through the belt driving unit,the mo-tor drives the driving sprocket in which the rotation rate has been reduced by the reduction ge arbox.The locus chain moves between the driving sprocket and upper sprocket which are vertically set.There's a special chain element in the locus chain,which drives the reciprocating holster with the main shaft linchpin and slide block.The r reciprocating g holster could only move up and down when the locus chain moves in a circle.In this way the up and down stroke of the sucker rod and the mac hine is realized.The lower end of the reciprocating holster is con-nected with the equilibrium system to make the structure balance.The balancing cylinder is re-placed by the balancing block to make the structure simplified. 展开更多
关键词 CHAIN DRIVE PUMPING unit STRUCTURAL design Optimization
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The Use of Spatial Sampling Designs in Business Surveys
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作者 Maria Michela Dickson Roberto Benedetti +1 位作者 Diego Giuliani Giuseppe Espa 《Open Journal of Statistics》 2014年第5期345-354,共10页
An innovative use of spatial sampling designs is here presented. Sampling methods which consider spatial locations of statistical units are already used in agricultural and environmental contexts, while they have neve... An innovative use of spatial sampling designs is here presented. Sampling methods which consider spatial locations of statistical units are already used in agricultural and environmental contexts, while they have never been exploited for establishment surveys. However, the rapidly increasing availability of geo- referenced information about business units makes that possible. In business studies, it may indeed be important to take into account the presence of spatial autocorrelation or spatial trends in the variables of interest, in order to have more precise and efficient estimates. The opportunity of using the most innovative spatial sampling designs in business surveys, in order to produce samples that are well spread in space, is here tested by means of Monte Carlo experiments. For all designs, the Horvitz-Thompson estimator of the population total is used both with equal and unequal inclusion probabilities. The efficiency of sampling designs is evaluated in terms of relative RMSE and efficiency gain compared with designs ignoring the spatial information. Furthermore, an evaluation of spatially balancing samples is also conducted. 展开更多
关键词 SPATIAL Sampling design BUSINESS surveys Horvitz-Thompson ESTIMATOR SPATIAL BALANCE
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Critical care practices in the world:Results of the global intensive care unit need assessment survey 2020
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作者 Faisal A Nawaz Neha Deo +3 位作者 Salim Surani William Maynard Martin L Gibbs Rahul Kashyap 《World Journal of Critical Care Medicine》 2022年第3期169-177,共9页
BACKGROUND There is variability in intensive care unit(ICU)resources and staffing worldwide.This may reflect variation in practice and outcomes across all health systems.AIM To improve research and quality improvement... BACKGROUND There is variability in intensive care unit(ICU)resources and staffing worldwide.This may reflect variation in practice and outcomes across all health systems.AIM To improve research and quality improvement measures administrative leaders can create long-term strategies by understanding the nature of ICU practices on a global scale.METHODS The Global ICU Needs Assessment Research Group was formed on the basis of diversified skill sets.We aimed to survey sites regarding ICU type,availability of staffing,and adherence to critical care protocols.An international survey‘Global ICU Needs Assessment’was created using Google Forms,and this was distributed from February 17^(th),2020 till September 23^(rd),2020.The survey was shared with ICU providers in 34 countries.Various approaches to motivating healthcare providers were implemented in securing submissions,including use of emails,phone calls,social media applications,and WhatsApp^(TM).By completing this survey,providers gave their consent for research purposes.This study was deemed eligible for category-2 Institutional Review Board exempt status.RESULTS There were a total 121 adult/adult-pediatrics ICU responses from 34 countries in 76 cities.A majority of the ICUs were mixed medical-surgical[92(76%)].108(89%)were adult-only ICUs.Total 36 respondents(29.8%)were 31-40 years of age,with 79(65%)male and 41(35%)female participants.89 were consultants(74%).A total of 71(59%)respondents reported having a 24-h inhouse intensivist.A total of 87(72%)ICUs were reported to have either a 2:1 or≥2:1 patient/nurse ratio.About 44%of the ICUs were open and 76%were mixed type(medical-surgical).Protocols followed regularly by the ICUs included sepsis care(82%),ventilator-associated pneumonia(79%);nutrition(76%),deep vein thrombosis prophylaxis(84%),stress ulcer prophylaxis(84%),and glycemic control(89%).CONCLUSION Based on the findings of this international,multi-dimensional,needs-assessment survey,there is a need for increased recruitment and staffing in critical care facilities,along with improved patientto-nurse ratios.Future research is warranted in this field with focus on implementing appropriate health standards,protocols and resources for optimal efficiency in critical care worldwide. 展开更多
关键词 Intensive care unit Critical care GLOBAL survey Intensive care unit survey Intensive care unit needs
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