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Study of Stress Sources and Critical Stress Combinations for the Input Shaft of a Longitudinally Mounted Four Speed Automotive Automatic Transmission Model
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作者 N. A. Abdel-Halim 《Modern Mechanical Engineering》 2013年第1期44-49,共6页
In the present paper;two models of the input shaft for a Longitudinal Mounted four Speed Automotive Automatic Transmission for the first time were introduced to describe the input shaft critical loads. In the first mo... In the present paper;two models of the input shaft for a Longitudinal Mounted four Speed Automotive Automatic Transmission for the first time were introduced to describe the input shaft critical loads. In the first model;the DC (Direct Clutch) connects two gears together. This gives no change in the set torque (the set output torque equal to the set input torque). In the second model;the ODB (Over Drive Brake) fixes one element of the planetary set. This is resulting, the gear set gives reduction ratio (the set output torque is not equal to the set input torque). So, the transmission input shaft is worked under two different working operating conditions of torque. Also, it is loaded by a two vertical loads which are coming from the turbine and planetary set loads respectively. They are shown that there are three critical combinations of forces (contact force, shear force, and normal force) applied on the input shaft. The critical forces can be possibility exist three types of cracks for the input shaft cross section they are: transverse (torsion stress), longitudinal (bending stress), and vertical (shear stress). The three cracks are studied in this article. The article considers three stress factors: shearing torsion stress, shear stress, and bending stress. 展开更多
关键词 ongitudinally Mounted Automotive automatic transmission Input SHAFT Stresses TORQUE CONVERTER TORQUE Ratio TORQUE CONVERTER WEIGHT Simple PLANETARY Gear Set WEIGHT
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Investigation of Self Excited Torsional Vibrations of Different Configurations of Automatic Transmission Systems during Engagement
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作者 Eid O. A. Abd Elmaksoud E M. Rabeih +1 位作者 N A Abdel-halim S M. El Demerdash 《Engineering(科研)》 2011年第12期1171-1181,共11页
The vehicle drive line system is subjected to torsional vibration from different sources of the system such as;engine fluctuating torque, Hook’s joint and the final drive. However, the essential source is the frictio... The vehicle drive line system is subjected to torsional vibration from different sources of the system such as;engine fluctuating torque, Hook’s joint and the final drive. However, the essential source is the friction torque induced in the friction elements, during their engagement. In the automatic transmission system, the planetary gear set includes several friction elements such as;clutch, band brakes, and one way clutch. During the engagement, severe torsional vibration is induced by friction which is noticeable by the passengers in the form of what so called vehicle shunt. In present paper, a torsional vibration model for Drive Line (DL) system includes three different configurations of automatic transmission is constructed. A computer program using MATLAB subroutines is implemented to obtain the system response. Effect of system parameters on the dynamic behavior and stability has been investigated. The system damping and the trend of the friction coefficient have an essential effect on the dynamic behavior and stability of the system. The system response is now predictable with change of the system parameters which opens up the opportunity in future to control the vibration level. 展开更多
关键词 SELF EXCITED Torsional Vibration Computer Simulation Ravigneaux PLANETARY GEAR SET Compound PLANETARY GEAR SET Longitudinally Mounted automatic transmission
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A Novel Cascaded PID Controller for Automatic Generation Control Analysis With Renewable Sources 被引量:5
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作者 Aurobindo Behera Tapas Kumar Panigrahi +1 位作者 PrakashK·Ray Arun Kumar Sahoo 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第6期1438-1451,共14页
Present day power scenarios demand a high quality uninterrupted power supply and needs environmental issues to be addressed. Both concerns can be dealt with by the introduction of the renewable sources to the existing... Present day power scenarios demand a high quality uninterrupted power supply and needs environmental issues to be addressed. Both concerns can be dealt with by the introduction of the renewable sources to the existing power system. Thus, automatic generation control(AGC) with diverse renewable sources and a modified-cascaded controller are presented in the paper.Also, a new hybrid scheme of the improved teaching learning based optimization-differential evolution(hITLBO-DE) algorithm is applied for providing optimization of controller parameters. A study of the system with a technique such as TLBO applied to a proportional integral derivative(PID), integral double derivative(IDD) and PIDD is compared to hITLBO-DE tuned cascaded controller with dynamic load change.The suggested methodology has been extensively applied to a 2-area system with a diverse source power system with various operation time non-linearities such as dead-band of, generation rate constraint and reheat thermal units. The multi-area system with reheat thermal plants, hydel plants and a unit of a wind-diesel combination is tested with the cascaded controller scheme with a different controller setting for each area. The variation of the load is taken within 1% to 5% of the connected load and robustness analysis is shown by modifying essential factors simultaneously by± 30%. Finally, the proposed scheme of controller and optimization technique is also tested with a 5-equal area thermal system with non-linearities. The simulation results demonstrate the superiority of the proposed controller and algorithm under a dynamically changing load. 展开更多
关键词 automatic generation control(AGC) cascaded CONTROLLER hybrid improved teaching learning based optimization-differential evolution(hITLBO-DE) algorithm INTEGRAL of SQUARE time multiplied by SQUARE error(ISTSE)
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OFDM Wireless Downhole Transmission Systems and Proposed SLM Method for PAPR Reduction 被引量:4
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作者 Renze Luo Yupu Dang +1 位作者 Rui Li Jiao Yang 《Communications and Network》 2014年第1期9-14,共6页
At present, mud pulse transmission systems are widely used in downhole data transmission. But the systems are very low in transmission efficiency, only 5-10 bits/s, with very large anti-inter-symbol-interference (ISI)... At present, mud pulse transmission systems are widely used in downhole data transmission. But the systems are very low in transmission efficiency, only 5-10 bits/s, with very large anti-inter-symbol-interference (ISI). It cannot meet high requirements for high-speed transmission of modern logging system. The development of communication technology has laid some foundation for this requirement. For this purpose, the Orthogonal Frequency Division Multiplexing (OFDM) Wireless Downhole Transmission Systems are proposed for the first time because of their high transmission rate, anti-inter-symbol-interference (ISI), and high spectral efficiency, etc. Due to non-linear power amplifier (PA) of logging systems with limited dynamic range, the drawbacks of high peak-average power ratio (PAPR) may outweigh all the potential benefits of OFDM wireless downhole transmission systems. Selective mapping (SLM) method can reduce the PAPR of OFDM logging signals without distortion. But at the receiver, the conventional SLM method needs exact bits of side information (SI) to recover the data signal. The probability of erroneous SI detection has a significant influence on the error performance of the system. And individual transmissions of SI result in the reduction of bandwidth efficiency. To restore the exact data signal, our scheme codes the SI bits by linear block codes (LBC), and is easily decoded by syndrome decoding. And then the coding SI bits are superimposed onto the logging signals to omit SI bits transmission. The theory and simulation results show that the proposed method has better performance than the conventional one. Accordingly, the OFDM wireless downhole transmission systems can tackle the high PAPR problem, and highten the transmission rate of logging signals. 展开更多
关键词 ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING WIRELESS DOWNHOLE transmission Systems ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) Logging While Drilling (LWD) Peak-to-Average Power Ratio (PAPR) Selected Mapping (SLM)
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Design of 1000-kV AC Single-Circuit Overhead Transmission Line
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作者 Li Yongwei1,Yuan Jun2,Zhao Quanjiang3,Cao Yujie4,Chen Haibo21.China Power Engineering Consulting Group Corporation 2.State Grid Corporation of China +1 位作者 3.Central Southern China Electric Power Design Institute 4.North China Electric Power Design Institute Co.Ltd. Wang Xingguo 《Electricity》 2010年第3期38-42,共5页
The UHVAC 1 000-kV transmission system is so far the one with the most advanced transmission technique applied and highest operation voltage.There are no guidelines or standards available for the design of 1 000-kV ov... The UHVAC 1 000-kV transmission system is so far the one with the most advanced transmission technique applied and highest operation voltage.There are no guidelines or standards available for the design of 1 000-kV overhead transmission line in China.Study on key technologies and design schemes shall be carried out to ascertain the technical principles and construction standards for project construction,which are presented in this paper based on the Southeast Shanxi-Nanyang-Jingmen test and demonstration transmission line.A comparison and analysis of technical data and economic indices between UHV line and other lines are also described. 展开更多
关键词 transmission LINE transmission LINE transmission technique project construction transmission system key technologies technical data DESIGN paper based principles comparison operation analysis Study test FAR
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Implementation of Mooring Automatic Positioning System for Deepwater Semi-Submersible Platform Based on Dual-Stage Actuator
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作者 Tao Sun Wenbin Gui +1 位作者 Zhigang Yu Zhimin Gao 《Open Journal of Modelling and Simulation》 2014年第2期67-76,共10页
The automatic positioning control of mooring system for deepwater semi-submersible platform has become a key issue in the research and development field of deep-sea resources. The Dual- Stage Actuator (DSA) proposed i... The automatic positioning control of mooring system for deepwater semi-submersible platform has become a key issue in the research and development field of deep-sea resources. The Dual- Stage Actuator (DSA) proposed in this paper can replace the single actuator to achieve the high speed and high precision positioning by cooperative control. The relative model and control algorithm of motion trajectory (CAMT) are designed and validated, which proves that the method proposed in this paper is effective. 展开更多
关键词 DEEPWATER SEMI-SUBMERSIBLE Platform MOORING automatic POSITIONING Dual-Stage Actuator (DSA) HIGH Speed and HIGH Precision the Control Algorithm of Motion Trajectory (CAMT)
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Automatic Scallion Seedling Feeding Mechanism with an Asymmetrical High-order Transmission Gear Train 被引量:1
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作者 Xiong Zhao Jun Ye +2 位作者 Mengyan Chu Li Dai Jianneng Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2020年第1期148-161,共14页
The current automatic scallion-transplanting machine is a complicated mechanism composed of two linkage mechanisms and two band carriers.It delivers seedlings ine ciently because of the movement limitations of the lin... The current automatic scallion-transplanting machine is a complicated mechanism composed of two linkage mechanisms and two band carriers.It delivers seedlings ine ciently because of the movement limitations of the linkage mechanism.This paper proposes a new high-order non-circular gear train for an automatic scallion-seedling feeding mechanism.The proposed gear train has an asymmetrical transmission ratio;i.e.,its transmission ratio varies.This allows the mechanism’s execution component to move in a long displacement and rotate in a large rotation angle.The long displacement enables the execution component to reach the designed working position,and the large rotation angle allows it to feed a scallion in the required pose.A mathematical model for calculating the asymmetrical transmission ratio was established according to the closure requirements and the full-cycle motion of the driven gear pitch curve.Then,the parameter-design model of the new seedling-feeding mechanism was established,based on precise pose points and trajectory-shape control points.Moreover,an aided-design program was developed to obtain the parameter-solution domain of the scallion-seedling feeding mechanism.The mechanism parameters,which met the seedling-feeding function,were optimized to determine the transmission ratio,using a program and a kinematic simulation.Finally,a prototype of the mechanism was produced,and a seedling-feeding experiment was carried out.One-thousand seedlings were tested at a rate of 100 seedlings per minute,and the statistical success rate was 93.4%.Thus,the automatic scallion-seedling feeding mechanism significantly improves the e ciency of automatically transplanting scallions. 展开更多
关键词 Asymmetric transmission Scallion TRANSPLANTING HIGH-ORDER GEAR NON-CIRCULAR GEAR Planetary GEAR train
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Homopteran Vector Biomarkers for Efficient Circulative Plant Virus Transmission are Conserved in Multiple Aphid Species and the Whitefly Bemisia tabaci 被引量:1
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作者 Michelle Cilia Michael Bereman +2 位作者 Tara Fish Michael J MacCoss stewart Gray 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第2期249-262,共14页
Plant viruses in the families Luteoviridae and Geminiviridae are phloem restricted and are transmitted in a persistent,circulative manner by homopteran insects.Using fluorescence 2-D difference gel electrophoresis to ... Plant viruses in the families Luteoviridae and Geminiviridae are phloem restricted and are transmitted in a persistent,circulative manner by homopteran insects.Using fluorescence 2-D difference gel electrophoresis to compare the proteomes of F2 genotypes of Schizaphis graminum segregating for virus transmission ability,we recently discovered a panel of protein biomarkers that predict vector competency.Here we used aphid and whitefly nucleotide and expressed sequence tag database mining to test whether these biomarkers are conserved in other homopteran insects.S.graminum gene homologs that shared a high degree of predicted amino acid identity were discovered in two other aphid species and in the whitefly Bemisia tabaci.Selected reaction monitoring mass spectrometry was used to validate the expression of these biomarkers proteins in multiple aphid vector species.The conservation of these proteins in multiple insect taxa that transmit plant viruses along the circulative transmission pathway creates the opportunity to use these biomarkers to rapidly identify insect populations that are the most efficient vectors and allow them to be targeted for control prior to the spread of virus within a crop. 展开更多
关键词 APHID WHITEFLY Schizaphis graminum Bemisia tabaci Acyrthosiphon pisum Toxoptera citricida Myzuspersicae proteomics biomarker circulative transmission BEGOMOVIRUS LUTEOVIRUS GEMINIVIRUS leaflaopper selected reaction monitoring SRM mass spectrometry targeted proteomics Skyline
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Design and dynamic simulation of hydraulic system of a new automatic transmission 被引量:15
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作者 王书翰 徐向阳 +3 位作者 刘艳芳 戴振坤 TEN BERGE P 曲巍 《Journal of Central South University》 SCIE EI CAS 2009年第4期697-701,共5页
A new hydraulic system of a novel automatic transmission (AT) was designed. The dimension and structure of valves and cylinders were designed by theoretical calculation. The dynamic simulation model of hydraulic syste... A new hydraulic system of a novel automatic transmission (AT) was designed. The dimension and structure of valves and cylinders were designed by theoretical calculation. The dynamic simulation model of hydraulic system of AT was established by ITI-SimulationX. Simulation results and theoretical design results were compared to confirm the simulation model. Based on the confirmed simulation model, the simulation results of pressure and flow of the hydraulic system were analyzed. The dynamic simulation method is very helpful for designing and analyzing the performance of hydraulic system and further optimization design. The theoretical design method and dynamic simulation model are feasible for the real industrial applications. The research results can be used in hydraulic system design and optimization. 展开更多
关键词 仿 仿
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An intelligent automatic correlation method of oilbearing strata based on pattern constraints:An example of accretionary stratigraphy of Shishen 100 block in Shinan Oilfield of Bohai Bay Basin,East China
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作者 WU Degang WU Shenghe +1 位作者 LIU Lei SUN Yide 《Petroleum Exploration and Development》 SCIE 2024年第1期180-192,共13页
Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thic... Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thickness,an intelligent automatic correlation method of oil-bearing strata based on pattern constraints is formed.We propose to introduce knowledge-driven in automatic correlation of oil-bearing strata,constraining the correlation process by stratigraphic sedimentary patterns and improving the similarity measuring machine and conditional constraint dynamic time warping algorithm to automate the correlation of marker layers and the interfaces of each stratum.The application in Shishen 100 block in the Shinan Oilfield of the Bohai Bay Basin shows that the coincidence rate of the marker layers identified by this method is over 95.00%,and the average coincidence rate of identified oil-bearing strata reaches 90.02% compared to artificial correlation results,which is about 17 percentage points higher than that of the existing automatic correlation methods.The accuracy of the automatic correlation of oil-bearing strata has been effectively improved. 展开更多
关键词 oil-bearing strata automatic correlation contrastive learning stratigraphic sedimentary pattern marker layer similarity measuring machine conditional constraint dynamic time warping algorithm
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Automatic recognition of depression based on audio and video:A review
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作者 Meng-Meng Han Xing-Yun Li +4 位作者 Xin-Yu Yi Yun-Shao Zheng Wei-Li Xia Ya-Fei Liu Qing-Xiang Wang 《World Journal of Psychiatry》 SCIE 2024年第2期225-233,共9页
Depression is a common mental health disorder.With current depression detection methods,specialized physicians often engage in conversations and physiological examinations based on standardized scales as auxiliary mea... Depression is a common mental health disorder.With current depression detection methods,specialized physicians often engage in conversations and physiological examinations based on standardized scales as auxiliary measures for depression assessment.Non-biological markers-typically classified as verbal or non-verbal and deemed crucial evaluation criteria for depression-have not been effectively utilized.Specialized physicians usually require extensive training and experience to capture changes in these features.Advancements in deep learning technology have provided technical support for capturing non-biological markers.Several researchers have proposed automatic depression estimation(ADE)systems based on sounds and videos to assist physicians in capturing these features and conducting depression screening.This article summarizes commonly used public datasets and recent research on audio-and video-based ADE based on three perspectives:Datasets,deficiencies in existing research,and future development directions. 展开更多
关键词 Depression recognition Deep learning automatic depression estimation System Audio processing Image processing Feature fusion Future development
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In situ atomic-scale observation of size-dependent (de) potassiation and reversible phase transformation in tetragonal FeSe anodes
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作者 Ran Cai Lixia Bao +12 位作者 Wenqi Zhang Weiwei Xia Chunhao Sun Weikang Dong Xiaoxue Chang Ze Hua Ruiwen Shao Toshio Fukuda Zhefei Sun Haodong Liu Qiaobao Zhang Feng Xu Lixin Dong 《InfoMat》 SCIE CAS CSCD 2023年第1期161-171,共11页
Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the explo... Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the exploration of appro-priate electrode materials with the correct size for reversibly accommodating large K+ions presents a significant challenge.In addition,the reaction mecha-nisms and origins of enhanced performance remain elusive.Here,tetragonal FeSe nanoflakes of different sizes are designed to serve as an anode for PIBs,and their live and atomic-scale potassiation/depotassiation mechanisms are revealed for the first time through in situ high-resolution transmission electron micros-copy.We found that FeSe undergoes two distinct structural evolutions,sequen-tially characterized by intercalation and conversion reactions,and the initial intercalation behavior is size-dependent.Apparent expansion induced by the intercalation of K+ions is observed in small-sized FeSe nanoflakes,whereas unexpected cracks are formed along the direction of ionic diffusion in large-sized nanoflakes.The significant stress generation and crack extension originating from the combined effect of mechanical and electrochemical interactions are elucidated by geometric phase analysis and finite-element analysis.Despite the different intercalation behaviors,the formed products of Fe and K_(2)Se after full potassiation can be converted back into the original FeSe phase upon depotassiation.In particular,small-sized nanoflakes exhibit better cycling perfor-mance with well-maintained structural integrity.This article presents the first successful demonstration of atomic-scale visualization that can reveal size-dependent potassiation dynamics.Moreover,it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs. 展开更多
关键词 elucidated by geometric phase analysis and finite-element analysis. Despite the different intercalation behaviors the formed products of Fe and K 2 Se after full potassiation can be converted back into the original FESE phase upon depotassiation. In particular small-sized nanoflakes exhibit better cycling perfor- mance with well-maintained structural integrity. This article presents the first successful demonstration of ATOMIC-SCALE visualization that can reveal size- dependent potassiation dynamics. Moreover it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs. KEYWOR DS in situ transmission electron microscopy potassium-ion batteries potassium-ion storage mechanism SIZE-DEPENDENT effects TETRAGONAL FESE
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Beliefs and practices of young women on utilization of prevention of mother to child transmission of HIV services in Malawi
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作者 Sadandaula Rose Muheriwa Angela Chimwaza +2 位作者 Alfred O. Maluwa Betty Mkwinda Nyasulu Mercy Pindani 《Health》 2013年第7期1172-1179,共8页
This study explored beliefs and actual practices of young women on utilization of Prevention of Mother to Child Transmission (PMTCT) of HIV services in Balaka district of Southern Malawi. The study design wascross sec... This study explored beliefs and actual practices of young women on utilization of Prevention of Mother to Child Transmission (PMTCT) of HIV services in Balaka district of Southern Malawi. The study design wascross sectional which utilized qualitative data collection and analysis methods. In-depth interviews were conducted on 12 young mothers of 15 to 24 years old. The respondents were drawn from 6 health centres in the district during their visits to either the under-five clinic, HIV and AIDS support groups or HIV follow up clinics. Data were analyzed using thematic analysis approach. Overall the respondents had positive beliefs on utilization of PMTCT services. They believed that adherence to PMTCT guidelines such as condom use, taking of Nevirapine (NVP) and exclusive breastfeeding protected the baby from contracting the virus. Nevertheless, all respondents believed that HIV testing was mandatory and that early weaning caused malnutrition and death of babies. Actual practice was very low. Very few young mothers breastfed exclusively, weaned their babies abruptly and took NVP as recommended. Not all positive beliefs translated into positive behavior. Lack of male support, inability of the midwives to provide comprehensive care to HIV infected mothers and their infants, and fear of stigma and discrimination were other factors that hindered utilization of PMTCT services. Culture was also a major barrier because traditionally babies are expected to be breastfed and supplements are fed to babies too. Therefore, there is a need to mobilize communities on PMTCT of HIV. Education programmes in HIV should emphasize behavior change interventions and should focus on both men and women and significant others. There is also need to intensify monitoring and evaluation of health workers’ activities to ensure that beliefs translate into positive behavior. 展开更多
关键词 PREVENTION of Mother to Child transmission of HIV HIV Positive Young Women BELIEFS on PMTCT SERVICES PMTCT Practice EXCLUSIVE Breast Feeding
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Automatic Identification for Laparoscopic Surgical Procedure for Ligation and Online Distinction of Abnormal Manipulation for Thread Knotting
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作者 Chiharu Ishii Takanori Sato +1 位作者 Kaito Murano Hideki Kawamura 《International Journal of Clinical Medicine》 2015年第12期887-898,共12页
Laparoscopic surgery is a difficult surgical procedure compared with laparotomy. In particular, considerable skills and care are required for thread knotting in laparoscopic surgery. In this paper, a method for automa... Laparoscopic surgery is a difficult surgical procedure compared with laparotomy. In particular, considerable skills and care are required for thread knotting in laparoscopic surgery. In this paper, a method for automatic identification of a laparoscopic surgical procedure for ligation and online distinction of an abnormality, defined as any unusual manipulation, in the identified surgical procedure is proposed. Ligation is divided into several individual surgical procedures, and on the basis of the threshold criteria, each surgical procedure is identified. Next, the identified surgical procedure, thread knotting, is classified as either normal or abnormal using a self-organizing map. Finally, to reduce surgical error, an abnormality warning system which warns detection of an unusual manipulation in the surgical procedure to the operator is constructed. 展开更多
关键词 automatic Identification of SURGICAL PROCEDURE DISTINCTION of ABNORMAL MANIPULATION in SURGICAL PROCEDURE Abnormality Warning System Surface Electromyogram (SEMG) Self-Organizing Map (SOM)
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Application of clutch to clutch gear shift technology for a new automatic transmission 被引量:4
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作者 鲁曦 王书翰 +1 位作者 刘艳芳 徐向阳 《Journal of Central South University》 SCIE EI CAS 2012年第10期2788-2796,共9页
For the purpose of engineering development for a new 8-step speed automatic transmission,a simplified dynamic model for this gearbox was established and key parameters which affected the shift quality were analyzed.Ai... For the purpose of engineering development for a new 8-step speed automatic transmission,a simplified dynamic model for this gearbox was established and key parameters which affected the shift quality were analyzed.Aiming at four different shift types,the ideal characteristics of shift clutch and engine control were set up.By using torque estimation method,PI slip control algorithm and engine coordinated control principle,the control model and transmission controller were well developed for three shift phases which included rapid-fill phase,torque phase and inertia phase.The testing environment on the rig and prototype vehicle level was built and the testing results obtained in ultimate condition could verify the accuracy and feasibility of this shift control strategy.The peak jerk during shift process was controlled within ±2 g/s where the smooth gearshift was obtained.The development proposal and algorithm have a high value for engineering application. 展开更多
关键词
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Design and Experimental Research on Seedling Pick-Up Mechanism of Planetary Gear Train with Combined Non-circular Gear Transmission 被引量:7
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作者 Yaxin Yu Jikun Liu +4 位作者 Bingliang Ye Gaohong Yu Xuejun Jin Liang Sun Junhua Tong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第3期42-54,共13页
Currently, transplanting mechanisms for dryland plug seedlings in China are mainly semiautomatic and have low efficiency. The rotary seedling pick-up mechanism with a planetary gear train for non-uniform intermittent ... Currently, transplanting mechanisms for dryland plug seedlings in China are mainly semiautomatic and have low efficiency. The rotary seedling pick-up mechanism with a planetary gear train for non-uniform intermittent transmission, and a concave and convex locking arc device, has a large rigid impact. To solve these problems, according to the design requirements for a dryland plug seedling transplanting mechanism, a rotary seedling pick-up mechanism of a planetary gear train with combined non-circular gear transmission of incomplete eccentric circular and noncircular gears was proposed. This has the characteristics of two-times greater fluctuation of the transmission ratio in a cycle, and can achieve a non-uniform continuous drive. Through analysis of the working principle of the seedling pick-up mechanism, its kinematics model was established. The human–computer interaction optimization method and self-developed computer-aided analysis and optimization software were used to obtain a set of parameters that satisfy the operation requirements of the seedling pick-up mechanism. According to the optimized parameters, the structure of the seedling pick-up mechanism was designed, a virtual prototype of the mechanism was created, and a physical prototype was manufactured. A virtual motion simulation of the mechanism was performed, high-speed photographic kinematics tests were conducted, and the kinematic properties of the physical prototype were investigated, whereby the correctness of the theoretical model and the optimized design of the mechanism were verified. Further, laboratory seedling pick-up tests were conducted. The success ratio of seedling pick-up was 93.8% when the seedling pick-up efficiency of the mechanism was 60 plants per minute per row, indicating that the mechanism has a high efficiency and success ratio for seedling pick-up and can be applied to a dryland plug seedling transplanter. 展开更多
关键词 Dryland plug SEEDLING transplanter Rotary SEEDLING PICK-UP MECHANISM transmission ratio Non-uniform continuous transmission COMBINED NON-CIRCULAR gear transmission Optimization design
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Model of an Atom by Analogy with the Transmission Line
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作者 Milan Perkovac 《Journal of Modern Physics》 2013年第7期899-903,共5页
Model of an atom by analogy with the transmission line is derived using Maxwell’s equations and Lorentz’ theory of electrons. To be realistic such a model requires that the product of the structural coefficient of L... Model of an atom by analogy with the transmission line is derived using Maxwell’s equations and Lorentz’ theory of electrons. To be realistic such a model requires that the product of the structural coefficient of Lecher’s transmission lines σ and atomic number Z is constant. It was calculated that this electromechanical constant is 8.27756, and we call it structural constant. This constant builds the fine-structure constant 1/α = 137.036, and with permeability μ, permittivity ε and elementary charge e builds Plank’s constant h. This suggests the electromagnetic character of Planck’s constant. The relations of energy, frequency, wavelength and momentum of electromagnetic wave in an atom are also derived. Finally, an equation, similar to Schrodinger’s equation, was derived, with a clear meaning of the wave function, which represents the electric or magnetic field strength of the observed electromagnetic wave. 展开更多
关键词 Lecher transmission Line Lorentz Theory of ELECTRONS Maxwells Equations Model of ATOM PLANCK CONSTANT Structural CONSTANT Transverse Mass Wave Equation
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Relationship between Maternal PBMC HBV cccDNA and HBV Serological Markers and its Effect on HBV Intrauterine Transmission 被引量:8
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作者 WANG Dan Dan YI Lin Zhu +7 位作者 WU Li Na YANG Zhi Qing HAO Hai Yun SHI Xiao Hong WANG Bo FENG Shu Ying FENG Yong Liang WANG Su Ping 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2019年第5期315-323,共9页
Objective To investigate the relationship between maternal peripheral blood mononuclear cells (PBMC) hepatitis B virus(HBV) covalenty closed circular deoxyribonucleic acid(cccDNA) and other HBV serological markers and... Objective To investigate the relationship between maternal peripheral blood mononuclear cells (PBMC) hepatitis B virus(HBV) covalenty closed circular deoxyribonucleic acid(cccDNA) and other HBV serological markers and its effects on HBV intrauterine transmission. Methods We enrolled 290 newborns and their hepatitis B surface antigen(HBsAg) positive mothers. HBV cccDNA in PBMC and HBV DNA in serum were detected by a real‐time PCR‐TaqM an probe while HBV serological markers were detected with an electrochemiluminescence immunoassay. Results There was a positive correlation between the levels of PBMC HBV cccD NA and serum HBV DNA and HBeA g(r = 0.436 and 0.403, P < 0.001). The detection rate of pattern A [‘HBsA g(+), HBeA g(+), and anti‐HBc(+)’] was significantly higher in the PBMC HBV cccD NA positive group than in the control group(χ^2 = 48.48, P < 0.001). There was a significant association between HBV intrauterine transmission and PBMC HBV cccD NA(χ^2 = 9.28, P = 0.002). In the presence of serum HBV DNA, HBeA g, and PBMC HBV cccD NA, the risk of HBV intrauterine transmission was three times higher(OR = 3.69, 95% CI: 1.30‐10.42) than that observed in their absence. The risk of HBV intrauterine transmission was the greatest(OR = 5.89, 95% CI: 2.35‐14.72) when both PBMC HBV cccD NA and pattern A were present. A Bayesian network model showed that maternal PBMC HBV cccD NA was directly related to HBV intrauterine transmission. Conclusion PBMC HBV cccDNA may be a direct risk factor for HBV intrauterine transmission. Our study suggests that serological markers could be combined with PBMC‐related markers in prenatal testing. 展开更多
关键词 Hepatitis B virus INTRAUTERINE transmission Peripheral blood MONONUCLEAR cells Covalently closed circular deoxyribonucleic acid SEROLOGICAL markers
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Design and application of electric oil pump in automatic transmission for efficiency improvement and start–stop function 被引量:1
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作者 刘艳芳 董鹏 +1 位作者 刘洋 徐向阳 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第3期570-580,共11页
For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmissi... For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function. 展开更多
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Automatic Detection Instrument for the Ratio of Chlorine to Bromine in Oxidized Liquid of Bromine Production Based on Fuzzy Method
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作者 Yu Naigong Wang Kaiyan 《仪器仪表学报》 EI CAS CSCD 北大核心 2006年第z1期159-161,共3页
In the process of bromine production,because of lag adjustment methods,there are problems of adjusting delay,raw material wastage and low growth rate.By considering the nature of bromine production,with the help of fu... In the process of bromine production,because of lag adjustment methods,there are problems of adjusting delay,raw material wastage and low growth rate.By considering the nature of bromine production,with the help of fuzzy data processing method,computer detection and display technique,we designed an automatic detection instrument for the ratio of chlorine to bromine in oxidized liquid of bromine production.This instrument can be used to detect the different parameters of raw materials adjustment and control in real time,and afford assurance that raw materials will be adjusted in time.This paper briefly introduces the working mechanism,hardware and software design of the instrument. 展开更多
关键词 BROMINE production fuzzy relation list RATIO of CHLORINE to BROMINE in OXIDIZED LIQUID OXIDIZING electric potential automatic detection
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