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Application of Opening and Closing Morphology in Deep Learning-Based Brain Image Registration
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作者 Yue Yang Shiyu Liu +4 位作者 Shunbo Hu Lintao Zhang Jitao Li Meng Li Fuchun Zhang 《Journal of Beijing Institute of Technology》 EI CAS 2023年第5期609-618,共10页
In order to improve the registration accuracy of brain magnetic resonance images(MRI),some deep learning registration methods use segmentation images for training model.How-ever,the segmentation values are constant fo... In order to improve the registration accuracy of brain magnetic resonance images(MRI),some deep learning registration methods use segmentation images for training model.How-ever,the segmentation values are constant for each label,which leads to the gradient variation con-centrating on the boundary.Thus,the dense deformation field(DDF)is gathered on the boundary and there even appears folding phenomenon.In order to fully leverage the label information,the morphological opening and closing information maps are introduced to enlarge the non-zero gradi-ent regions and improve the accuracy of DDF estimation.The opening information maps supervise the registration model to focus on smaller,narrow brain regions.The closing information maps supervise the registration model to pay more attention to the complex boundary region.Then,opening and closing morphology networks(OC_Net)are designed to automatically generate open-ing and closing information maps to realize the end-to-end training process.Finally,a new registra-tion architecture,VM_(seg+oc),is proposed by combining OC_Net and VoxelMorph.Experimental results show that the registration accuracy of VM_(seg+oc) is significantly improved on LPBA40 and OASIS1 datasets.Especially,VM_(seg+oc) can well improve registration accuracy in smaller brain regions and narrow regions. 展开更多
关键词 three dimensional(3D)medical image registration deep learning opening operation closing operation MORPHOLOGY
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Panorama of the Opening-Closing Tectonics Theory in China 被引量:2
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作者 YANGWeiran ZHENGJiandong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第6期1229-1234,共6页
The opening-closing tectonics theory, a theory about opening-closing tectonics, is a viewpoint regarding geotectonics suggested by a group of Chinese scientists. Opening and closing are two basic geological movements,... The opening-closing tectonics theory, a theory about opening-closing tectonics, is a viewpoint regarding geotectonics suggested by a group of Chinese scientists. Opening and closing are two basic geological movements, which may result in a series of structures. The highest level of opening is the appearance of oceans and the highest level of closing is the consolidation of continents. Based on field investigations, the authors consider that identifying the marks of opening-closing tectonics is the basis of the issue and classifying the types of opening-closing tectonics is the key of the issue. This paper briefly discusses the substance and the future of the study on the opening-closing tecton cs in China. The authors hope to share relevant information with geoscientists in the world in this field. 展开更多
关键词 China opening-closing tectonics opening-closing cycle opening-closing type
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Analysis of the Heat Transfer Efficiency of an Automobile Engine under Different Grille Opening and Closing Conditions 被引量:1
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作者 Jian Song 《Fluid Dynamics & Materials Processing》 EI 2022年第2期345-354,共10页
Computational Fluid Dynamics is used to assess the thermal(heat transfer)performances of an automobile engine considering different grille opening and closing degrees.For this purpose the entire vehicle is modelled an... Computational Fluid Dynamics is used to assess the thermal(heat transfer)performances of an automobile engine considering different grille opening and closing degrees.For this purpose the entire vehicle is modelled and three fundamental aspects are examined,namely,the open area of the air intake grille,the position of the upper and lower grilles and their shape.The results show that the opening area and position of the grille have some influence also on the aerodynamic characteristics of the automobile.With an increase in the opening angle of the grille,the CD(Drag Coefficient)value of the whole vehicle becomes higher.When the air intake grille of the car is fully open or closed,the CD value is 0.35434 or 0.31777,respectively,that is,the flow resistance in the engine compartment accounts for 10.32%of the CD value for the whole automobile. 展开更多
关键词 Air intake grille opening and closing degree automobile engine heat transfer function simulation and optimization
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Value of negative pressure sealing drainage on wound healing of Gustilo IIIB and IIIC open fractures
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作者 Bo Fang Yong-Sheng Wang +2 位作者 Wei Li Kai Ying Gang Zong 《World Journal of Clinical Cases》 SCIE 2024年第20期4199-4205,共7页
BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has... BACKGROUND Gustilo III fractures have a high incidence and are difficult to treat.Patients often experience difficulty in wound healing.Negative pressure drainage technology can help shorten wound healing time and has positive value in improving patient prognosis.AIM To explore the clinical value of the negative pressure sealing drainage technique in wound healing of Gustilo IIIB and IIIC open fractures.METHODS Eighty patients with Gustilo IIIB and IIIC open fractures with skin and soft tissue injuries who were treated in the Second People’s Hospital of Dalian from March 2019 to December 2021 were selected as the research subjects.They were divided into a study group(n=40,healed with negative pressure closed drainage)and a control group(n=40,healed with conventional dressing changes)according to the variation in the healing they received.The efficacy of the clinical interventions,the variations in the regression indicators(time to wound healing,time to fracture healing,time to hospitalization),and the conversion and healing of bacterial wounds were compared 1-3 mo after the intervention.RESULTS The total effective rate of patients among the study group was 95.00%(38/40),which was notably higher than 75.00%(30/40)among the control group(P<0.05).The wound healing time,fracture healing time,and hospital stay of the patients in the study group was shorter than the control group(P<0.05).After the intervention,the negative bacterial culture at the wound site rate and wound healing rate of the patients among the study group increased compared to the control group(P<0.05).CONCLUSION Negative pressure sealing and drainage technology has a good therapeutic effect on patients with Gustilo IIIB and IIIC open fracture wounds with skin and soft tissue injury.It can notably enhance the wound healing rate and the negative rate of bacteria on the wound surface and help to speed up the recovery process of patients. 展开更多
关键词 Negative pressure closed drainage Gustilo type III open fracture Wound healing Clinical outcome Research value
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Late Precambrian Scissors--Type Opening--Closing Tectonics and Its Dynamics in South China 被引量:1
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作者 Xu Zhigang Institute of Mineral Deposits, Chinese Academy of Geological Sciences, Beijing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1996年第2期109-122,共14页
In this paper the author first reviews 6 major advances in the study of Precambrian geologyand tectonics of South China during the last decade, and then proposes the following new modelof Late Precambrian scissors-typ... In this paper the author first reviews 6 major advances in the study of Precambrian geologyand tectonics of South China during the last decade, and then proposes the following new modelof Late Precambrian scissors-type opening-closing tectonic evolution in the region. (1) Besidesthe Middle-Late Proterozoic low-grade metamorphic basement, there existed a LateArchaean-Early Proterozoic medium- to high-garde metamorphic basement in South China;both of them formed the united Yangtze-Cathaysia (craton) at the end of the Early Proterozoic,with the Jiangxi-Anhui-Zhejiang palaeogulf extending into the inland and the Jiangxi-Anhui-Jiangsu Peninsula lying on the northern side of the palaeogulf.(2) From the Middle Proterozoic,the present Guangxi-Guizhou-Hunan area in the western-central oldland was subjected toextensional rifting and became a rift trough, thus resulting in counterclockwise rotation of the'Cathaysian block' and clockwise rotation of the 'Yangtze block'; moreover, the southwardcompression of the Dabie-Jiaonan block which split from the southern margin of the NorthChina plate and was accreted to the northern margin of the Jiangxi-Anhui-Jiangsu Peninsula ledto the scissors-type closing of the Jiangxi-Anhui-Zhejiang palaeogulf during the Middle-earlyLate Proterozoic, which further influenced the Early Palaeozoic tectonic evolution of the region. 展开更多
关键词 Yangtze-Cathaysia Jiangxi-Anhui-Zhejiang palaeogulf Late Precambrian scissors-type opening-closing tectonics
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OPEN表和CLOSED表的合一 被引量:2
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作者 冯乃勤 王岁花 +1 位作者 郑延斌 冯国燚 《计算机工程与应用》 CSCD 北大核心 2003年第16期100-101,125,共3页
在人工智能传统的搜索方法中,一直是将OPEN表和CLOSED表分开的。这不仅增加了搜索算法的复杂性,久而久之,也许禁锢了人们的思想。文章试图改变这种状况,提出了一种与众不同的新思路,巧妙地将OPEN表和CLOSED表合二为一,减少了一些工作量... 在人工智能传统的搜索方法中,一直是将OPEN表和CLOSED表分开的。这不仅增加了搜索算法的复杂性,久而久之,也许禁锢了人们的思想。文章试图改变这种状况,提出了一种与众不同的新思路,巧妙地将OPEN表和CLOSED表合二为一,减少了一些工作量,在一定程度上降低了算法的复杂性。 展开更多
关键词 搜索 0PEN表 CLOSED表 算法复杂性
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Comparison between open phase fault of arc suppression coil and single phase to earth fault in coal mine distribution network 被引量:3
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作者 LI Xiao-bo WANG Chong-lin 《Journal of China University of Mining and Technology》 EI 2008年第3期368-372,共5页
When, in a coal mine distribution network whose neutral point is grounded by an arc suppression coil (ASC), a fault occurs in the ASC, compensation cannot be properly realized. Furthermore, it can damage the safe and ... When, in a coal mine distribution network whose neutral point is grounded by an arc suppression coil (ASC), a fault occurs in the ASC, compensation cannot be properly realized. Furthermore, it can damage the safe and reliable run of the network. We first introduce a three-phase five-column arc suppression coil (TPFCASC) and discuss its autotracking compensation theory. Then we compare the single phase to ground fault of the coal mine distribution network with an open phase fault at the TPFCASC using the Thévenin theory, the symmetrical-component method and the complex sequence network respectively. The results show that, in both types of faults, zero-sequence voltage of the network will appear and the maximum magnitude of this zero-sequence voltage is different in both faults. Based on this situation, a protection for the open phase fault at the TPFCASC should be estab-lished. 展开更多
关键词 open phase PROTECTION single phase to ground fault three-phase five-column arc suppression coil (TPFCASC)
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Internal Lateral Sphincterotomy in Yaounde: Comparative Short-Term Results of Open versus Closed Techniques 被引量:1
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作者 Georges Bwelle Motto Yannick Mahamat Ekani Boukar +4 位作者 Guy Aristide Bang Joseph Cyrille Chopkeng Ngoumfe Fabrice Tientcheu Tim Arthur Essomba Maurice Aurélien Sosso 《Surgical Science》 2021年第11期374-380,共7页
<b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:Verdana;"></span><b> </b><span style="font-family:Verdan... <b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:Verdana;"></span><b> </b><span style="font-family:Verdana;">Chronic anal fissure is a benign disorder which is associated with considerable discomfort. </span><span style="font-family:Verdana;"><b></b></span><b><b><span style="font-family:Verdana;">Aim of the Work:</span></b><span style="font-family:;" "=""><span style="font-family:Verdana;"></span></span></b><b> </b><span style="font-family:;" "=""><span style="font-family:Verdana;">The aim of this study was to compare the post-operative results of open and closed internal lateral sphincterotomies in the short and medium term.</span><b> </b></span><span style="font-family:Verdana;"><b></b></span><b><b><span style="font-family:Verdana;">Patient and Methods:</span></b><span style="font-family:;" "=""><span style="font-family:Verdana;"></span></span></b><b> </b><span style="font-family:Verdana;">We carried out a prospective randomized comparative study in the digestive and visceral surgery departments of Central Hospital of Yaounde over a period of 15</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">months. Patients were evaluated for each technique by several variables, including duration of surgery, post-operative pain, recurrence, surgical wound infection, gas and/or stool incontinence, and healing time with follow-up up to 12</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">months postoperatively.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;"><b></b></span><b><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:;" "=""><span style="font-family:Verdana;"></span></span></b><b> </b><span style="font-family:Verdana;">A total of 63 patients underwent surgery within them we had 32 open lateral internal sphincterotom</span><span style="font-family:Verdana;">ies</span><span style="font-family:Verdana;"> (group 1) and 31 closed lateral internal sphincterotom</span><span style="font-family:Verdana;">ies</span><span style="font-family:Verdana;"> (group 2). There were 35 men and 28 women with a sex ratio of 1.25. The mean age was 35.36 ± 10.16 years with extremes ranging from 19 to 62 years. The typical presentation was pain on defecation. The majority of fissures were located at the posterior commissure. The average duration of the procedure was longer in patients in group 1 (15.34 minutes) compared to 5.22 minutes in patients in group 2. We found 3.12% of surgical wound infections in patients in group 1 and neither patient in group 2. Gas incontinence was 6.45% in group 2 patients and 28.12% in group 1.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">The mean intensity of pain at 24 hours post-operative was between</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">4 and 6 on </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">visual analogue scale in patients in group 2 and between 7 and 10 in group 1. Wound healing time was 8.9 days in group </span><span style="font-family:Verdana;">1</span><span style="font-family:Verdana;"> and 4 days in group 2 patients. The hospital stay was 24 hours for both groups of patients. No recurrence was noted during the 6-month</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">follow-up period.</span><b> </b></span><span style="font-family:;" "=""><span style="font-family:Verdana;"><b></b></span><b><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"></span></b></span><b> </b><span style="font-family:Verdana;">Closed lateral internal anal sphincterotomy is the treatment of choice for chronic anal fissures because it is effective and associated with </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">lower complication rate than the open sphincterotomy technique.</span> 展开更多
关键词 Anal Fissure Internal Lateral Sphincterotomy open Technique Close Technique
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Open-closed Loop ILC Corrected with Angle Relationship of Output Vectors for Tracking Control of Manipulator 被引量:8
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作者 WANG Hong-Bin WANG Yan 《自动化学报》 EI CSCD 北大核心 2010年第12期1758-1765,共8页
关键词 ILC 自动化 跟踪控制 仿真
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Open-plus-closed-loop control for chaotic motion of 3D rigid pendulum 被引量:2
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作者 戈新生 邹奎 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第4期403-412,共10页
An open-plus-closed-loop (OPCL) control problem for the chaotic motion of a 3D rigid pendulum subjected to a constant gravitationM force is studied. The 3D rigid pendulum is assumed to be consist of a rigid body sup... An open-plus-closed-loop (OPCL) control problem for the chaotic motion of a 3D rigid pendulum subjected to a constant gravitationM force is studied. The 3D rigid pendulum is assumed to be consist of a rigid body supported by a fixed and frictionless pivot with three rotational degrees. In order to avoid the singular phenomenon of Euler's angular velocity equation, the quaternion kinematic equation is used to describe the motion of the 3D rigid pendulum. An OPCL controller for chaotic motion of a 3D rigid pendulum at equilibrium position is designed. This OPCL controller contains two parts: the open-loop part to construct an ideal trajectory and the closed-loop part to stabilize the 3D rigid pendulum. Simulation results show that the controller is effective and efficient. 展开更多
关键词 3D rigid pendulum QUATERNION chaotic motion Poincar section open-plus-closed-loop (OPCL) control
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TRANSFER OPEN OR CLOSED SETVALUED MAPPING AND GENERALIZ-ATION OF H-KKM THEOREM WITH APPLICATIONS
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作者 李秉友 苏家宝 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1994年第10期981-987,共7页
In this paper ,we introduce a class of generalized mapping called transfer open orclosed valued mapping to generalize the KKM theorem on H-space.Then asapplications,using our H-KKM theorem,we prove some coincidence th... In this paper ,we introduce a class of generalized mapping called transfer open orclosed valued mapping to generalize the KKM theorem on H-space.Then asapplications,using our H-KKM theorem,we prove some coincidence theorems.matching theorems and vector valued minimax inequalities which generalize slightly thecorresponding results in[1,2,4,5,6,7]. 展开更多
关键词 transfer closed or open setvalued mapping coincidence theorem.H-KKM mapping matching theorem
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A screw dislocation near one open inhomogeneity and another closed inhomogeneity both permitting constant interior stresses
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作者 Xu WANG Ping YANG P.SCHIAVONE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第2期173-182,共10页
We prove that the interior stresses within both a non-parabolic open inhomogeneity and another interacting non-elliptical closed inhomogeneity can still remain constant when the matrix is simultaneously under the acti... We prove that the interior stresses within both a non-parabolic open inhomogeneity and another interacting non-elliptical closed inhomogeneity can still remain constant when the matrix is simultaneously under the action of a screw dislocation and uniform remote anti-plane stresses.The constancy of interior stresses is realized through the construction of a conformal mapping function for the doubly connected domain occupied by the surrounding matrix.The mapping function is endowed with the information describing the screw dislocation via the incorporation of two specifically defined logarithmic terms.The constant interior stress fields are observed to be independent of the specific open and closed shapes of the two inhomogeneities and the existence of the screw dislocation.In contrast,the existence of the neighboring screw dislocation significantly affects the open and closed shapes of the two inhomogeneities. 展开更多
关键词 constant stress field open inhomogeneity closed inhomogeneity screw dislocation conformal mapping
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Effects of subject’s wakefulness state and health status on approximated entropy during eye opening and closure test of routine EEG examination
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作者 Maen Alaraj Tadanori Fukami Fumito Ishikawa 《Journal of Biomedical Science and Engineering》 2012年第2期75-94,共20页
This study tested a novel method designed to provide useful information for medical diagnosis and treatment. We measured electroencephalography (EEG) during a test of eye opening and closing, a common test in routine ... This study tested a novel method designed to provide useful information for medical diagnosis and treatment. We measured electroencephalography (EEG) during a test of eye opening and closing, a common test in routine EEG examination. This test is mainly used for measuring the degree of alpha blocking and sensitivity during eyes opening and closing. However, because these factors depend on the subject’s awareness, drowsiness can interfere with accurate diagnosis. We sought to determine the optimal EEG frequency band and optimal brain region for distinguishing healthy individuals from patients suffering from several neurophysiological diseases (including dementia, cerebrovascular disorder, schizophrenia, alcoholism, and epilepsy) while fully awake, and while in an early drowsy state. We tested four groups of subjects (awake healthy subjects, drowsy healthy subjects, awake patients and drowsy patients). The complexity of EEG band frequencies over five lobes in the human brain was analyzed using wavelet-based approximate entropy (ApEn). Two-way analysis of variance tested the effects of the two factors of interest (subjects’ health state, and subjects’ wakefulness state) on five different lobes of the brain during eyes opening and closing. The complexity of the theta and delta bands over frontal and central regions, respectively, was significantly greater in the healthy state during eyes opening. In contrast, patients exhibited increased complexity of gamma band activity over the temporal region only, during eyes-close. The early drowsy state and wakefulness state increased the complexity of theta band activity over the temporal region only during eyes-close and eyes-open states respectively, and this change was significantly greater in control subjects compared with patients. We propose that this method may be useful in routine EEG examination, to aid medical doctors and clinicians in distinguishing healthy individuals from patients, regardless of whether the subject is fully awake or in the early stages of drowsiness. 展开更多
关键词 EEG ROUTINE EXAMINATION Eyes opening and closing TEST Discrete Wavelet Approximate ENTROPY
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Free torsion of thin-walled structural members of open-and closed-sections
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作者 Long-yuan LI D.EASTERBROOK 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第1期25-32,共8页
Free torsion of thin-walled structures of open- and closed-sections is a classical elastic mechanics problem, which, in literature, is often solved by the method of membrane analogy. The method of membrane analogy, ho... Free torsion of thin-walled structures of open- and closed-sections is a classical elastic mechanics problem, which, in literature, is often solved by the method of membrane analogy. The method of membrane analogy, however, can be only applied to structures of a single material. If the structure consists of both open- and closed-sections, the method of membrane analogy is difficult to be applied. In this paper, a new method is presented for solving the free torsion of thin-walled structures of open- and/or closed- sections with multiple materials. By utilizing a simple statically indeterminate concept, torsional equations are derived based on the equilibrium and compatibility conditions. The method presented here not only is very simple and easy to understand but also can be applied to thin-walled structures of combined open- and closed-sections with multiple materials. 展开更多
关键词 TORSION THIN-WALLED open-section closed-section shear flow shear stress
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Between Closeness and Openness --An Understanding of Guild Characteristics from the Succession of Industrial and Commercial Management Right of Baxian County in Qing Dynasty
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《长江师范学院学报》 2012年第7期138-140,共3页
关键词 《长江师范学院学报》 英文摘要 期刊 编辑工作
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基于SSA−LSTM的风速异常波动检测方法 被引量:3
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作者 邓立军 袁金波 +1 位作者 刘剑 尚文天 《煤炭科学技术》 EI CAS CSCD 北大核心 2024年第3期139-147,共9页
针对传统统计方法对风门开闭导致传感器监测数据异常波动的漏报率和误报率高的问题,通过挖掘风速传感器中时间序列数据中的数据特征,提出了一种基于奇异谱分析法(SSA)与长短期记忆神经网络(LSTM)组合的SSA−LSTM风速异常波动检测方法。... 针对传统统计方法对风门开闭导致传感器监测数据异常波动的漏报率和误报率高的问题,通过挖掘风速传感器中时间序列数据中的数据特征,提出了一种基于奇异谱分析法(SSA)与长短期记忆神经网络(LSTM)组合的SSA−LSTM风速异常波动检测方法。首先利用SSA对风速传感器监测数据进行预处理,将风速数据分解为趋势分量、周期分量和噪声分量,通过重组趋势分量和噪声分量去除因湍流脉动产生的数据噪声;然后对LSTM进行参数优化,利用优化后的LSTM模型对预处理数据进行预测并得到重构风速;最后以对数概率密度函数计算监测风速与重构风速的异常分数,通过计算训练集数据样本的异常分数设定阈值对监测风速进行异常检测。试验结果表明:SSA去除因湍流脉动产生的数据噪声效果较好,在不影响数据波动情况下去除噪声分量,有助于提高风速重构效果和异常检测准确率;LSTM在无异常波动时能正确重构因湍流脉动导致的小幅波且与实际数据拟合效果较好,在有异常波动时根据历史波动趋势对异常波动段进行重构,可有效提高异常检测的准确率。通过对比分析,所提方法比ARIMA、BP、CNN模型的重构效果更好,异常检测准确率为99.2%,F1-Score为0.97,验证了所提方法的可靠性。表明本文所提方法在检测因风门开闭导致的风速异常波动上具有一定的应用价值。 展开更多
关键词 异常波动 风门开闭 异常检测 奇异谱分析 长短期记忆 时间序列
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“枢经学说”的哲学思考
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作者 李建敏 唐宏亮 +7 位作者 庞军 王开龙 王雄将 谭树生 卢栋明 刘振威 梁英业 胡庆 《辽宁中医杂志》 CAS 北大核心 2024年第9期30-33,共4页
中医“枢经学说”源自经典著作《黄帝内经》中的“开阖枢”理论,该理论最初用于解释三阴三阳的作用和相互关系,经引申、衍化、发展、升华后,用来分析、阐释、推演中医现象,指导中医临床。通过探讨“开阖枢”与经络之气、脏腑功能、五官... 中医“枢经学说”源自经典著作《黄帝内经》中的“开阖枢”理论,该理论最初用于解释三阴三阳的作用和相互关系,经引申、衍化、发展、升华后,用来分析、阐释、推演中医现象,指导中医临床。通过探讨“开阖枢”与经络之气、脏腑功能、五官九窍、肢体关节的关系,阐释了枢经学说的关系本体论内涵;通过探讨认识客体的历史客观性、认识主体的主观能动性、科学的实践观,阐释了枢经学说之辨证的认识论内涵;并且提出了下一步的研究愿景和初步构想。 展开更多
关键词 枢经学说 开阖枢 哲学思考
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有机玻璃管道直接水锤压力特性试验研究
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作者 张小莹 边少康 +2 位作者 冯梦雪 陆伟 张健 《排灌机械工程学报》 CSCD 北大核心 2024年第1期37-42,共6页
为了了解黏弹性管道的水锤压力特性,文中通过搭建水库-管道-阀门系统模型,进行了系列关阀水锤试验,针对有机玻璃管道中末端阀门初始开度分别为30%,100%时关阀产生的直接水锤压力变化规律进行了研究,从黏弹性材料的本构关系角度分析了关... 为了了解黏弹性管道的水锤压力特性,文中通过搭建水库-管道-阀门系统模型,进行了系列关阀水锤试验,针对有机玻璃管道中末端阀门初始开度分别为30%,100%时关阀产生的直接水锤压力变化规律进行了研究,从黏弹性材料的本构关系角度分析了关阀时间对黏弹性材料直接水锤的影响机理,并对2种不同初始开度下阀门附近的流场进行了三维数值模拟.研究结果表明:黏弹性管道中直接水锤压力变化规律与传统的水锤理论不符,直接水锤压力不仅与阀门的关闭时间有关,还与阀门的初始开度有关,满足“阀门关闭越快,直接水锤压力越大”与“阀门初始开度越小,直接水锤压力越大”的规律. 展开更多
关键词 黏弹性管道 直接水锤 关阀时间 阀门开度 试验研究
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食品包装热成型机电动八杆开合模机构的运动及受力分析
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作者 谢志刚 陈小芹 许智扬 《食品与机械》 CSCD 北大核心 2024年第1期90-94,共5页
目的:解决热成型机的核心部件开合模机构相关杆件设计及其分析技术难题。方法:运用解析法阐述了一种热成型机的电动八杆开合模机构的运动和受力分析。结果:基于实例计算得到执行滑块位移与曲柄转角关系曲线,并进一步推导了速度和加速度... 目的:解决热成型机的核心部件开合模机构相关杆件设计及其分析技术难题。方法:运用解析法阐述了一种热成型机的电动八杆开合模机构的运动和受力分析。结果:基于实例计算得到执行滑块位移与曲柄转角关系曲线,并进一步推导了速度和加速度变化规律;同时还揭示了片材挤压阶段的理论合模力和各杆件受力变化趋势及特点。结论:实现了在不具备专业软件的条件下对电动八杆开合模机构的分析,缩短了设计和试制周期。 展开更多
关键词 热成型机 开合模机构 八杆 连杆机构 食品包装
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物料转运设备闭式泵控多马达行走液压系统
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作者 刘杰 宁博 +3 位作者 丘铭军 张永峰 彭立广 温肖 《重型机械》 2024年第1期94-98,共5页
某生产线超大超重物料在生产转运过程中工况要求非常高,特别是要求行走驱动系统稳定可靠且能耗低装机功率小。通过对比分析传统常用的比例阀控马达同步行走液压系统和闭式泵控多马达行走液压系统原理和技术特点,最终以闭式泵控多马达行... 某生产线超大超重物料在生产转运过程中工况要求非常高,特别是要求行走驱动系统稳定可靠且能耗低装机功率小。通过对比分析传统常用的比例阀控马达同步行走液压系统和闭式泵控多马达行走液压系统原理和技术特点,最终以闭式泵控多马达行走液压系统作为生产线试验台实验对象,对其加载和停止过程中马达进出油口压力进行了试验研究,为未来闭式泵控多马达行走液压系统在重载转运设备的批量生产使用提供指导。 展开更多
关键词 闭式泵 液压系统 开式系统 超大超重物料
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