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Analysis of the Gravity-1 Sea Launch System and Technical Features
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作者 ZHANG Tao HUANG Shuai +2 位作者 Ma Ma BU Xiangwei XU Guoguang 《Aerospace China》 2024年第1期18-27,共10页
Sea launch has the characteristics of flexible launching points, high landing area safety, and good economy. In recent years, it has become one of the important launch methods. Since 2019, China has carried out a tota... Sea launch has the characteristics of flexible launching points, high landing area safety, and good economy. In recent years, it has become one of the important launch methods. Since 2019, China has carried out a total of 11 successful sea launches. The Gravity-1(YL-1) sea launch system consists of a launch vehicle system and a sea launch platform. The sea launch program includes roll on/roll off boarding, sea mooring, sea maneuvering, anchoring and positioning, system testing, and formal launch. Through the maiden flight of YL-1, the design and manufacturing technology of large tonnage dedicated launch ship, launch vehicle vertical transfer and roll on/roll off boarding technology, anti-shake technology for sea launch, simple inflatable flexible insulation protective cover technology, and remote wireless measurement and control technology have been fully verified. 展开更多
关键词 YL-1 sea launch system technical features
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Analysis of OSA Syndrome from PPG Signal Using CART-PSO Classifier with Time Domain and Frequency Domain Features 被引量:1
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作者 N.Kins Burk Sunil R.Ganesan B.Sankaragomathi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2019年第2期351-375,共25页
Obstructive Sleep Apnea(OSA)is a respiratory syndrome that occurs due to insufficient airflow through the respiratory or respiratory arrest while sleeping and sometimes due to the reduced oxygen saturation.The aim of ... Obstructive Sleep Apnea(OSA)is a respiratory syndrome that occurs due to insufficient airflow through the respiratory or respiratory arrest while sleeping and sometimes due to the reduced oxygen saturation.The aim of this paper is to analyze the respiratory signal of a person to detect the Normal Breathing Activity and the Sleep Apnea(SA)activity.In the proposed method,the time domain and frequency domain features of respiration signal obtained from the PPG device are extracted.These features are applied to the Classification and Regression Tree(CART)-Particle Swarm Optimization(PSO)classifier which classifies the signal into normal breathing signal and sleep apnea signal.The proposed method is validated to measure the performance metrics like sensitivity,specificity,accuracy and F1 score by applying time domain and frequency domain features separately.Additionally,the performance of the CART-PSO(CPSO)classification algorithm is evaluated through comparing its measures with existing classification algorithms.Concurrently,the effect of the PSO algorithm in the classifier is validated by varying the parameters of PSO. 展开更多
关键词 OBSTRUCTIVE sleep APNEA photoplethysmogram SIGNAL time DOMAIN features frequency DOMAIN features classification and regression tree CLASSIFIER particle swarm optimization algorithm.
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An Approach to Fault Diagnosis of Rotating Machinery Using the Second-Order Statistical Features of Thermal Images and Simplified Fuzzy ARTMAP
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作者 Faisal Al Thobiani Van Tung Tran Tiedo Tinga 《Engineering(科研)》 2017年第6期524-539,共16页
Thermal image, or thermogram, becomes a new type of signal for machine condition monitoring and fault diagnosis due to the capability to display real-time temperature distribution and possibility to indicate the mach... Thermal image, or thermogram, becomes a new type of signal for machine condition monitoring and fault diagnosis due to the capability to display real-time temperature distribution and possibility to indicate the machine’s operating condition through its temperature. In this paper, an investigation of using the second-order statistical features of thermogram in association with minimum redundancy maximum relevance (mRMR) feature selection and simplified fuzzy ARTMAP (SFAM) classification is conducted for rotating machinery fault diagnosis. The thermograms of different machine conditions are firstly preprocessed for improving the image contrast, removing noise, and cropping to obtain the regions of interest (ROIs). Then, an enhanced algorithm based on bi-dimensional empirical mode decomposition is implemented to further increase the quality of ROIs before the second-order statistical features are extracted from their gray-level co-occurrence matrix (GLCM). The highly relevant features to the machine condition are selected from the total feature set by mRMR and are fed into SFAM to accomplish the fault diagnosis. In order to verify this investigation, the thermograms acquired from different conditions of a fault simulator including normal, misalignment, faulty bearing, and mass unbalance are used. This investigation also provides a comparative study of SFAM and other traditional methods such as back-propagation and probabilistic neural networks. The results show that the second-order statistical features used in this framework can provide a plausible accuracy in fault diagnosis of rotating machinery. 展开更多
关键词 Thermal Images SECOND-ORDER Statistical features Gray-Level CO-OCCURRENCE Matrix Minimum Redundancy Maximum RELEVANCE Rotating Machinery Fault Diagnosis Simplified Fuzzy ARTMAP
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石板优化加工虚拟技术的研究 被引量:4
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作者 赵民 彭新楚 邵萌 《沈阳建筑大学学报(自然科学版)》 EI CAS 2005年第2期160-163,共4页
目的利用虚拟技术来解决石板优化加工提高石材大板的利用率.方法通过石板特征采集仪将石材大板的3个主要特征即尺寸特征、轮廓特征、表面纹理特征采集到CAD系统中,并基于VB对串口编程技术和AutoCAD二次开发技术来建立石板的虚拟原型库.... 目的利用虚拟技术来解决石板优化加工提高石材大板的利用率.方法通过石板特征采集仪将石材大板的3个主要特征即尺寸特征、轮廓特征、表面纹理特征采集到CAD系统中,并基于VB对串口编程技术和AutoCAD二次开发技术来建立石板的虚拟原型库.结果通过虚拟原型库对具有不规则外型的石材大板进行实时优化排样,避开石材了表面空洞、大斑等缺陷.同时可对工程区域进行模拟铺设,检查纹理走向、色彩搭配.还能帮助ERP系统指导生产,精确调整库存和采购.结论利用此仪器可建立石材板材的虚拟原型库,改善石板型材的加工,可提高材料的利用率,提高墙面和地面整体的美观性,减少型材上的缺陷,也便于库存和采购的管理. 展开更多
关键词 AutoCAD CAD ERP VB
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中国直立人形态特征的变异——颅骨测量数据的统计分析 被引量:10
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作者 刘武 张银运 《人类学学报》 CSCD 北大核心 2005年第2期121-136,共16页
近年,亚洲直立人化石特征的变异及其意义引起了学术界较多的关注。不断有学者提出周口店直立人无论在非测量性特征,还是在测量特征方面都具有不同于印度尼西亚及非洲直立人的表现特点,有人甚至对将周口店直立人化石特征作为直立人的典... 近年,亚洲直立人化石特征的变异及其意义引起了学术界较多的关注。不断有学者提出周口店直立人无论在非测量性特征,还是在测量特征方面都具有不同于印度尼西亚及非洲直立人的表现特点,有人甚至对将周口店直立人化石特征作为直立人的典型特征的观点提出了置疑。为进一步探讨这些有争议的问题,本文采用多变量统计分析方法对33件非洲和欧亚地区直立人颅骨测量数据进行了分析。我们发现亚洲大陆的周口店和南京直立人与生活在东南亚群岛的印度尼西亚直立人具有不同的颅骨测量特征。中国标本以较窄的前额部和枕部,以及宽阔的颅骨中部为特点。而印度尼西亚标本的额部和枕部的宽度与颅骨中部的宽度相对较为接近。非洲直立人在这些颅骨测量特征的表现上与印度尼西亚直立人接近,呈现出相对宽阔的额部和枕部。中国的和县直立人在颅骨测量特征的表现上与印度尼西亚和非洲直立人接近,而与周口店和南京直立人明显不同。基于这些发现,本文就直立人头骨测量特征的稳定性、周口店直立人颅骨特征的表现特点、东亚直立人的地区变异与时代变化、头骨形态与测量特征的对应性等问题进行了讨论。 展开更多
关键词 西
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First and Second Order Statistics Features for Classification of Magnetic Resonance Brain Images
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作者 Namita Aggarwal R. K. Agrawal 《Journal of Signal and Information Processing》 2012年第2期146-153,共8页
In literature, features based on First and Second Order Statistics that characterizes textures are used for classification of images. Features based on statistics of texture provide far less number of relevant and dis... In literature, features based on First and Second Order Statistics that characterizes textures are used for classification of images. Features based on statistics of texture provide far less number of relevant and distinguishable features in comparison to existing methods based on wavelet transformation. In this paper, we investigated performance of texture-based features in comparison to wavelet-based features with commonly used classifiers for the classification of Alzheimer’s disease based on T2-weighted MRI brain image. The performance is evaluated in terms of sensitivity, specificity, accuracy, training and testing time. Experiments are performed on publicly available medical brain images. Experimental results show that the performance with First and Second Order Statistics based features is significantly better in comparison to existing methods based on wavelet transformation in terms of all performance measures for all classifiers. 展开更多
关键词 Alzheimers Disease Magnetic RESONANCE Imaging Feature Extraction Discrete WAVELET TRANSFORM FIRST and Second Order Statistical features
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Digital Economy: A Vision From The Future
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作者 Valentina Bondarenko 《Journal of Economic Science Research》 2020年第1期16-23,共8页
The article shows that the foundation of the digital economy can be a new paradigm for predicting the future from the future,i.e.from the future in which the development goal has already been achieved.This allows to m... The article shows that the foundation of the digital economy can be a new paradigm for predicting the future from the future,i.e.from the future in which the development goal has already been achieved.This allows to minimize all costs and completely avoid incorrect system solutions of the existing trial-and-error approach.Using the achievements of the technological revolution of Industry 4.0,an effective digital economy can be formed only when it is seen as an economy of coordinated interests between the state,business,society and the interests of each individual in real time at every local level.This will make it possible to solve the problem of ensuring the high quality of life not of citizens in general,but of each individual. 展开更多
关键词 Glushkov VM OGAS Scientific and technical progress Industry 4.0 Digital economy CRISIS New methodological tools GOAL Complexity Integrity CONSISTENCY Interdisciplinarity A SINGLE indicator A SINGLE criterion of efficiency Forecasting the FUTURE from the FUTURE
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Epidemiological and clinical features,treatment status,and economic burden of traumatic spinal cord injury in China:a hospital-based retrospective study 被引量:5
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作者 Hengxing Zhou Yongfu Lou +32 位作者 Lingxiao Chen Yi Kang Lu Liu Zhiwei Cai David BAnderson Wei Wang Chi Zhang Jinghua Wang Guangzhi Ning Yanzheng Gao Baorong He Wenyuan Ding Yisheng Wang Wei Mei Yueming Song Yue Zhou Maosheng Xia Huan Wang Jie Zhao Guoyong Yin Tao Zhang Feng Jing Rusen Zhu Bin Meng Li Duan Zhongmin Zhang Desheng Wu Zhengdong Cai Lin Huang Zhanhai Yin Kainan Li Shibao Lu Shiqing Feng 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第5期1126-1132,共7页
Traumatic spinal cord injury is potentially catastrophic and can lead to permanent disability or even death.China has the largest population of patients with traumatic spinal cord injury.Previous studies of traumatic ... Traumatic spinal cord injury is potentially catastrophic and can lead to permanent disability or even death.China has the largest population of patients with traumatic spinal cord injury.Previous studies of traumatic spinal cord injury in China have mostly been regional in scope;national-level studies have been rare.To the best of our knowledge,no national-level study of treatment status and economic burden has been performed.This retrospective study aimed to examine the epidemiological and clinical features,treatment status,and economic burden of traumatic spinal cord injury in China at the national level.We included 13,465 traumatic spinal cord injury patients who were injured between January 2013 and December 2018 and treated in 30 hospitals in 11 provinces/municipalities representing all geographical divisions of China.Patient epidemiological and clinical features,treatment status,and total and daily costs were recorded.Trends in the percentage of traumatic spinal cord injuries among all hospitalized patients and among patients hospitalized in the orthopedic department and cost of care were assessed by annual percentage change using the Joinpoint Regression Program.The percentage of traumatic spinal cord injuries among all hospitalized patients and among patients hospitalized in the orthopedic department did not significantly change overall(annual percentage change,-0.5%and 2.1%,respectively).A total of 10,053(74.7%)patients underwent surgery.Only 2.8%of patients who underwent surgery did so within 24 hours of injury.A total of 2005(14.9%)patients were treated with high-dose(≥500 mg)methylprednisolone sodium succinate/methylprednisolone(MPSS/MP);615(4.6%)received it within 8 hours.The total cost for acute traumatic spinal cord injury decreased over the study period(-4.7%),while daily cost did not significantly change(1.0%increase).Our findings indicate that public health initiatives should aim at improving hospitals’ability to complete early surgery within 24 hours,which is associated with improved sensorimotor recovery,increasing the awareness rate of clinical guidelines related to high-dose MPSS/MP to reduce the use of the treatment with insufficient evidence. 展开更多
关键词 China clinical features COSTS EPIDEMIOLOGY methylprednisolone sodium succinate METHYLPREDNISOLONE retrospective study traumatic spinal cord injury TREATMENT
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滇西无量山逆冲推覆带山前飞来峰的构造成因 被引量:9
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作者 王世锋 王二七 《地质学报》 EI CAS CSCD 北大核心 2005年第3期317-322,共6页
印度板块相对于我国华南地块的向北运动在滇西三江地区造成许多地块发生大规模的顺时针旋转,其中,由于刚性度上的差异,临沧花岗岩基的旋转对邻近地块的影响最为明显,导致兰坪—思茅盆地的大规模缩短和无量山的隆升。无量山的隆升是一系... 印度板块相对于我国华南地块的向北运动在滇西三江地区造成许多地块发生大规模的顺时针旋转,其中,由于刚性度上的差异,临沧花岗岩基的旋转对邻近地块的影响最为明显,导致兰坪—思茅盆地的大规模缩短和无量山的隆升。无量山的隆升是一系列逆冲断片的叠置造成的,其中,古生界无量山群浅变质岩位于最上部,三叠系麦初箐组含煤砂板岩位于中部,侏罗-白垩系红层位于最下部。在无量山的北东山前散布有许多飞来峰,盖在侏罗-白垩系红层之上,由于这些飞来峰的岩性和无量山群及麦初箐组很相似,前人将其视为推覆体。近年来,笔者针对这些飞来峰的变形和地貌特征以及与无量山的构造关系开展系统研究,认为它们是在重力作用下从无量山滑覆下来的岩块,并在滑覆的过程中岩石发生了掀斜。无量山的顶部山峰大多位于同一高度,十分平坦,代表一次侵蚀夷平事件,这说明在推覆造山之后发生过大规模的侵蚀作用,在此之前无量山要高的多,因此造山带边缘的推覆岩片具有很大的势能,这是重力滑覆作用得以发生的条件。可以推测飞来峰的滑覆发生在造山期后,很可能发生在无量山大规模的侵蚀作用期间,因为在此时大气降水多,山体边坡稳定性差。 展开更多
关键词 西 -
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织物表面折皱的小波分析与自组织神经网络等级评定 被引量:4
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作者 杨晓波 黄秀宝 《中国图象图形学报(A辑)》 CSCD 北大核心 2005年第4期473-478,共6页
为了提取较为精细的图像信息,引入了多尺度2维小波分析织物的表面折皱。织物图像首先经过高斯滤波,再利用小波变换分解并从中提取高频信息,然后结合4种表征织物折皱的特征参数,计算不同折皱等级模板的特征值,通过分析特征值与折皱等级... 为了提取较为精细的图像信息,引入了多尺度2维小波分析织物的表面折皱。织物图像首先经过高斯滤波,再利用小波变换分解并从中提取高频信息,然后结合4种表征织物折皱的特征参数,计算不同折皱等级模板的特征值,通过分析特征值与折皱等级的相关系数,表明这4种特征参数可以作为模式识别的输入量;最后采用Kohonen自组织神经网络客观评定织物的折皱等级,自组织神经网络将不同等级的织物折皱模板进行分类,并以此为依据,确定26种不同织物类型的折皱等级。为了定量描述评定结果,通过计算客观评定与主观评定结果的相关系数,验证该方法的可行性。 展开更多
关键词 KOHONEN
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Retrospective analysis of pathological types and imaging features in pancreatic cancer: A comprehensive study
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作者 Yang-Gang Luo Mei Wu Hong-Guang Chen 《World Journal of Gastrointestinal Oncology》 SCIE 2025年第1期121-129,共9页
BACKGROUND Pancreatic cancer remains one of the most lethal malignancies worldwide,with a poor prognosis often attributed to late diagnosis.Understanding the correlation between pathological type and imaging features ... BACKGROUND Pancreatic cancer remains one of the most lethal malignancies worldwide,with a poor prognosis often attributed to late diagnosis.Understanding the correlation between pathological type and imaging features is crucial for early detection and appropriate treatment planning.AIM To retrospectively analyze the relationship between different pathological types of pancreatic cancer and their corresponding imaging features.METHODS We retrospectively analyzed the data of 500 patients diagnosed with pancreatic cancer between January 2010 and December 2020 at our institution.Pathological types were determined by histopathological examination of the surgical spe-cimens or biopsy samples.The imaging features were assessed using computed tomography,magnetic resonance imaging,and endoscopic ultrasound.Statistical analyses were performed to identify significant associations between pathological types and specific imaging characteristics.RESULTS There were 320(64%)cases of pancreatic ductal adenocarcinoma,75(15%)of intraductal papillary mucinous neoplasms,50(10%)of neuroendocrine tumors,and 55(11%)of other rare types.Distinct imaging features were identified in each pathological type.Pancreatic ductal adenocarcinoma typically presents as a hypodense mass with poorly defined borders on computed tomography,whereas intraductal papillary mucinous neoplasms present as characteristic cystic lesions with mural nodules.Neuroendocrine tumors often appear as hypervascular lesions in contrast-enhanced imaging.Statistical analysis revealed significant correlations between specific imaging features and pathological types(P<0.001).CONCLUSION This study demonstrated a strong association between the pathological types of pancreatic cancer and imaging features.These findings can enhance the accuracy of noninvasive diagnosis and guide personalized treatment approaches. 展开更多
关键词 Pancreatic cancer Pathological types Imaging features Retrospective analysis Diagnostic accuracy
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Product Image Classification Based on Fusion Features
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作者 杨晓慧 刘静静 杨利军 《Chinese Quarterly Journal of Mathematics》 2015年第3期429-441,共13页
Two key challenges raised by a product images classification system are classification precision and classification time. In some categories, classification precision of the latest techniques, in the product images cl... Two key challenges raised by a product images classification system are classification precision and classification time. In some categories, classification precision of the latest techniques, in the product images classification system, is still low. In this paper, we propose a local texture descriptor termed fan refined local binary pattern, which captures more detailed information by integrating the spatial distribution into the local binary pattern feature. We compare our approach with different methods on a subset of product images on Amazon/e Bay and parts of PI100 and experimental results have demonstrated that our proposed approach is superior to the current existing methods. The highest classification precision is increased by 21% and the average classification time is reduced by 2/3. 展开更多
关键词 product image CLASSIFICATION FAN refined local binary pattern(FRLBP) PYRAMID HISTOGRAM of orientated gradients(PHOG) FUSION features
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日本汽车产业的构造特征与发展趋向 被引量:2
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作者 孙明贵 《现代日本经济》 CSSCI 2005年第3期31-35,共5页
日本汽车产业按照产业序列不同将汽车整车厂家和零部件厂家组织成金字塔型结构,在这种构造中,整车企业与众多的零部件企业建立了系列化的、连续交易制度,这种制度在20世纪90年代后受到挑战。汽车厂家受市场不振的影响,逐渐调整经营战略... 日本汽车产业按照产业序列不同将汽车整车厂家和零部件厂家组织成金字塔型结构,在这种构造中,整车企业与众多的零部件企业建立了系列化的、连续交易制度,这种制度在20世纪90年代后受到挑战。汽车厂家受市场不振的影响,逐渐调整经营战略,采取了扩大海外生产、改革零部件采购方式、削减产品成本和部件单元化与标准化以及缩短新车开发周期等主要措施。零部件企业也根据汽车厂家的战略变化调整了自己的生存战略。 展开更多
关键词 2090
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Diffuse large B-cell lymphoma arising from follicular lymphoma with warthin’s tumor of the parotid gland-immunophenotypic and genetic features: A case report 被引量:1
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作者 Chang-Song Wang Xia Chu +5 位作者 Di Yang Lei Ren Nian-Long Meng Xue-Xia Lv Tian Yun Yan-Sha Cao 《World Journal of Clinical Cases》 SCIE 2019年第22期3895-3903,共9页
BACKGROUND Warthin’s tumor(WT)is composed of several cysts that are lined with tall,bilayered oncocytic columnar cells and lymphoid stroma.Within WT,the two components rarely transform into carcinoma or lymphoma,and ... BACKGROUND Warthin’s tumor(WT)is composed of several cysts that are lined with tall,bilayered oncocytic columnar cells and lymphoid stroma.Within WT,the two components rarely transform into carcinoma or lymphoma,and when it does,carcinoma is the most common type.Approximately 28 cases of lymphoma with WT have been reported,most of which were non-Hodgkin lymphomas,and only a few cases were Hodgkin lymphomas.In the present report,we studied a case of diffuse large B cell lymphoma(DLBCL)arising from follicular lymphoma(FL)with WT in the parotid gland and its immunophenotypic and genetic features.CASE SUMMARY A 67-year-old man presented with a slowly enlarging right cheek mass for 12 years,and the mass began to change in size over a 2-mo time period.Over time,the patient felt mild local pain and right cheek discomfort.His medical history included a hepatitis B virus infection for 20 years and 30 years of smoking.Gross examination of the excised specimen showed a gray-red and gray-white appearance and a soft texture lobulated external surface neoplasm that measured 9 cm×8 cm×7 cm and was well circumscribed by relative normal parotid gland tissue.In cross section,the cut surfaces of the neoplasm were multicystic and had a homogeneous scaly appearance.A small fluid was discovered in the cyst.Bilateral oxyphilic,cuboidal or polygonal epithelium cells and lymphoid intraparenchymal components were observed.Many medium-to large-sized lymphoid cells were observed diffusely in part of the neoplasm,and a few secondary lymphoid follicles were observed at the center or edge of the neoplasm.Immunohistochemical staining showed that the columnar oncocytic cells were positive for AE1/AE3;neoplastic cells located in coarctate follicular were positive for CD20,Pax-5,bcl-2 and bcl-6;and the adjacent diffusely medium-to large-sized lymphoid cells were positive for Pax-5,bcl-6,CD20,MUM-1,bcl-2 and CD79a.The bcl-6(3q27)break-apart rearrangement was observed,and an Epstein Barr virus test was negative in the tumor cells.The patient survived 6 months after being diagnosed without any treatment.CONCLUSION WT-associated lymphoma is a very rare neoplasm in the parotid gland.Most cases are B cell non-Hodgkin lymphomas and involve middle-age and older males.This case highlights the extremely rare association of DLBCL arising from FL with WT and the importance of deliberate evaluation of the WT intraparenchymal stroma.Molecular detection techniques have potential advantages in the diagnosis of lymphoma with WT. 展开更多
关键词 DIFFUSE large B cell LYMPHOMA Warthins TUMOR PAROTID GLAND Follicularlymphoma Case report GENETIC feature
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A STUDY ON THE TECHNICAL PROPERTIES OF PEPSET NO-BAKE RESIN-BONDED SAND AND FACTORS HAVING INFLUENCE
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作者 杨晶 赵丽萍 程军 《兵工学报》 EI CAS CSCD 北大核心 2000年第1期-,共3页
通过试验研究了PEPSET树脂自硬砂工艺应用于铝铸件生产的性能及其影响因素。指出 PEPSET 树脂自硬砂工艺在硬化速度、流动性、发气性、溃散性等方面性能良好, 利于复杂铝铸件的造型制芯,有望成为树脂自硬砂工艺的一个重要发展方向。
关键词 PEPSET A STUDY ON THE technical PROPERTIES OF PEPSET NO-BAKE
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青藏高原东南部MCC的地域特点分析 被引量:28
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作者 杨本湘 陶祖钰 《气象学报》 CAS CSCD 北大核心 2005年第2期236-242,共7页
青藏高原东南部是一个对流天气频繁发生的地区.在该地区生成发展的MCC不仅给当地造成大范围的雷电和强降水天气,还对长江中下游地区的天气产生明显的影响.文中通过对2001~2002年6~9月发生在该地区的16个MCC个例的分析,得出其具有明显... 青藏高原东南部是一个对流天气频繁发生的地区.在该地区生成发展的MCC不仅给当地造成大范围的雷电和强降水天气,还对长江中下游地区的天气产生明显的影响.文中通过对2001~2002年6~9月发生在该地区的16个MCC个例的分析,得出其具有明显的地域特点:(1) MCC最易发生在100°E附近的横断山脉地区和105°E附近的成都平原地区,且后者多于前者;(2) 它们都具有生命史短,水平尺度较小和生消变化快的特点,但东部型生消时间晚,降水量大;西部型生消时间早,降水量小;(3) 东部型和西部型MCC发生前的环流背景和成熟阶段的垂直结构也有明显不同.东部型MCC在形成前中低层有明显的水汽输送,在成熟阶段中低层有较强的正涡度环流,有较弱的垂直风切变,具有较为典型的MCC特征;而西部型MCC在形成前中低层水汽输送不明显,成熟阶段的正涡度环流不强,处于较强高空急流的正下方,具有与强风暴相类似的一些特征. 展开更多
关键词 MCC 2001~2002 西
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Identification of Question and Non-Question Segments in Arabic Monologues Using Prosodic Features: Novel Type-2 Fuzzy Logic and Sensitivity-Based Linear Learning Approaches
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作者 Sunday Olusanya Olatunji Lahouari Cheded +1 位作者 Wasfi G. Al-Khatib Omair Khan 《Journal of Intelligent Learning Systems and Applications》 2013年第3期165-175,共11页
In this paper, we extend our previous study of addressing the important problem of automatically identifying question and non-question segments in Arabic monologues using prosodic features. We propose here two novel c... In this paper, we extend our previous study of addressing the important problem of automatically identifying question and non-question segments in Arabic monologues using prosodic features. We propose here two novel classification approaches to this problem: one based on the use of the powerful type-2 fuzzy logic systems (type-2 FLS) and the other on the use of the discriminative sensitivity-based linear learning method (SBLLM). The use of prosodic features has been used in a plethora of practical applications, including speech-related applications, such as speaker and word recognition, emotion and accent identification, topic and sentence segmentation, and text-to-speech applications. In this paper, we continue to specifically focus on the Arabic language, as other languages have received a lot of attention in this regard. Moreover, we aim to improve the performance of our previously-used techniques, of which the support vector machine (SVM) method was the best performing, by applying the two above-mentioned powerful classification approaches. The recorded continuous speech is first segmented into sentences using both energy and time duration parameters. The prosodic features are then extracted from each sentence and fed into each of the two proposed classifiers so as to classify each sentence as a Question or a Non-Question sentence. Our extensive simulation work, based on a moderately-sized database, showed the two proposed classifiers outperform SVM in all of the experiments carried out, with the type-2 FLS classifier consistently exhibiting the best performance, because of its ability to handle all forms of uncertainties. 展开更多
关键词 ARABIC Monologues Prosodic features Type-2 FUZZY LOGIC Systems Sensitivity Based LINEAR LearningMethod Support Vector Machines
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原发性肝癌肿瘤微血管形态特征与其生物学特性的关系 被引量:6
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作者 李功杰 杨立 +2 位作者 史晓林 盛复庚 乔鹏岗 《世界华人消化杂志》 CAS 北大核心 2005年第13期1503-1506,共4页
目的:探讨HCC肿瘤微血管特征与其大小、细胞分化程度、DSA血供分型等生物学特性的关系. 方法:选取手术切除前做过血管造影且未做栓塞治疗的HCC标本32例.对不同分化程度、大小、DSA血供分型肝癌的MVD、肿瘤微血管直径、肿瘤梁索直径、肿... 目的:探讨HCC肿瘤微血管特征与其大小、细胞分化程度、DSA血供分型等生物学特性的关系. 方法:选取手术切除前做过血管造影且未做栓塞治疗的HCC标本32例.对不同分化程度、大小、DSA血供分型肝癌的MVD、肿瘤微血管直径、肿瘤梁索直径、肿瘤微血管梁索直径比进行相关统计学分析. 结果:随HCC生长,肿瘤微血管分型有增高的趋势(rs=0.55,P=0.001):肝癌DSA血供分型随肿瘤微血管分型增加呈增加的趋势(rs=0.56,P=0.001);不同大小肝癌MVD不同,3-5 cm组肝癌的MVD最大,与≤3 cm及>5 cm组比P=0.005及P:0.016:随HCC 生长,微血管直径有增高的趋势;肿瘤MVD在乏血供、中等血供、富血供HCC中分别为45.34±21.18、69.50±54.18和61.56±38.94,乏血供组MVD明显小于中等血供和富血供组(P=0.014,P=0.031).肿瘤微血管直径、微血管梁索直径比有随HCC血供分级由乏血供至富血供有明显的增加趋势,乏血供HCC肿瘤微血管直径明显低于富血供HCC(P=0.044),其血管梁索直径比明显低于中等血供和富血供组(P=0.017, P=0.008);富血供HCC与中等血供相比,MVD基本相似,而富血供HCC的微血管直径有大于中等血供HCC的趋势;MVD与肝癌分化程度无关(P>0.05). 结论:HCC在生长的不同阶段,其肿瘤微血管特征是不同的,并有一定的发展规律;HCC的DSA不同血供类型之间有明显的肿瘤微血管特征差异. 展开更多
关键词 HCC MVD DSA HCC
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基于电子地图的遥感影像自动粗定位研究 被引量:6
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作者 徐建斌 洪文 +2 位作者 刘喆 吴一戎 向茂生 《测试技术学报》 EI 2005年第1期91-94,共4页
 在GIS的基础上,提出了一种新的遥感图像自动定位方法.将GIS技术和遥感技术相结合,利用GIS软件从电子地图中提取出线状图层一定范围内各点的经纬度坐标,将这些信息作为参考源,同时对遥感图像进行二值化和边沿提取,将提取出来的遥感图...  在GIS的基础上,提出了一种新的遥感图像自动定位方法.将GIS技术和遥感技术相结合,利用GIS软件从电子地图中提取出线状图层一定范围内各点的经纬度坐标,将这些信息作为参考源,同时对遥感图像进行二值化和边沿提取,将提取出来的遥感图像的线状特征作为目标源,然后在分辨率匹配和投影变换的基础上对二者进行匹配,引入Hausdorff距离作为相似性测度,最后获取遥感图像的定位信息. 展开更多
关键词 HAUSDORFF GIS GIS 沿 线
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麦蚜对小麦冠层光谱特性的影响研究 被引量:30
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作者 乔红波 程登发 +3 位作者 孙京瑞 田喆 陈林 林芙蓉 《植物保护》 CAS CSCD 北大核心 2005年第2期21-26,共6页
通过对田间不同程度麦蚜危害的小麦冠层反射光谱测量,研究了各波段反射光谱的变异特征,并对光谱反射曲线进行微分分析。结果表明:在麦蚜危害的初期,近红外反射率明显降低,即陡坡效应受到明显的削弱,随着麦蚜危害程度加重,小麦冠层的反... 通过对田间不同程度麦蚜危害的小麦冠层反射光谱测量,研究了各波段反射光谱的变异特征,并对光谱反射曲线进行微分分析。结果表明:在麦蚜危害的初期,近红外反射率明显降低,即陡坡效应受到明显的削弱,随着麦蚜危害程度加重,小麦冠层的反射率在不同波段有明显下降,尤其在近红外区下降更为显著。利用光谱微分技术,对受麦蚜不同程度危害的小麦冠层反射率求一阶导数,得到红边斜率。结果表明,麦蚜危害后小麦冠层的红边斜率在近红外波段发生剧烈的变化,且随着危害程度的加重其值逐步下降。将归一化植被指数(NDVI)分别和百株蚜量进行相关及回归分析,并对监测蚜虫敏感波段的选择做了初步的探讨。 展开更多
关键词 线
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