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DEVELOPMENT OF A HYBRID MODEL FOR THREE-DIMENSIONAL GIS 被引量:14
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作者 SHI Wenzhong 《Geo-Spatial Information Science》 2000年第2期6-12,共7页
This paper presents a hybrid model for three-dimensional Geographical Information Systems which is an integration of surface- and volume-based models. The Triangulated Irregular Network (TIN) and octree models are int... This paper presents a hybrid model for three-dimensional Geographical Information Systems which is an integration of surface- and volume-based models. The Triangulated Irregular Network (TIN) and octree models are integrated in this hybrid models. The TIN model works as a surface-based model which mainly serves for surface presentation and visualization. On the other hand, the octree encoding supports volumetric analysis. The designed data structure brings a major advantage in the three-dimensional selective retrieval. This technique increases the efficiency of three-dimensional data operation. 展开更多
关键词 hybrid three-dimensional model TIN model octree model gis
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浅谈GIS技术在避难场所选址中的应用
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作者 杨舒 杨振华 +1 位作者 田茗瑜 王琨 《科学技术创新》 2025年第1期84-87,共4页
随着GIS技术的不断发展,GIS技术在选址领域的优势日益显著,目前已成为该领域研究使用的重要技术手段。本文以包头市中心城区现有的中小学操场作为紧急避难场所的备选点,应用LA模型理论,运用GIS空间分析和网络分析方法,构建紧急避难场所... 随着GIS技术的不断发展,GIS技术在选址领域的优势日益显著,目前已成为该领域研究使用的重要技术手段。本文以包头市中心城区现有的中小学操场作为紧急避难场所的备选点,应用LA模型理论,运用GIS空间分析和网络分析方法,构建紧急避难场所配置模型,讨论其作为紧急避难场所的选址情况,并进行数量优化。最终从102个备选点中确定55个点作为紧急避难场所选址点。本研究可为城市防震减灾规划的紧急避难场所区位优化提供理论基础。 展开更多
关键词 gis空间分析 公共设施区位配置模型(LA模型) 包头市中心城区 紧急避难场
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基于BIM+GIS的高速公路基础设施数字化基础平台研究
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作者 沈国焱 周栓科 +3 位作者 尹光明 刘武 吕若丹 张茜 《价值工程》 2025年第1期46-49,共4页
公路工程建设周期长、专业多、数据资料类型多、基础信息结构化程度低,要实现公路全周期、多要素的数字化建设,必然会面临海量数据的融合、处理、维护等,传统信息化系统构架或者人工管理方式,无法完成相关工作,导致公路工程数据全周期... 公路工程建设周期长、专业多、数据资料类型多、基础信息结构化程度低,要实现公路全周期、多要素的数字化建设,必然会面临海量数据的融合、处理、维护等,传统信息化系统构架或者人工管理方式,无法完成相关工作,导致公路工程数据全周期流转与共享不畅,海量数据集成与管理困难。传统业务数字化建设系统性差,现有系统多基于某具体业务或工点,导致业务数据兼容性、标准性、统一性难以支撑全生命周期的传递与应用。本文提出基于BIM+GIS的高速公路基础设施数字化基础平台,在解决上述痛点的同时,旨在实现道路全要素、全周期、全业务、数字化管理应用基础数据支撑。作为基础底座,为建管、养护和营运等业务系统提供标准化的道路要素数据、应用接口以及道路设施设备的2D/3D模型和高精度地图等可视化服务和支撑。 展开更多
关键词 公路工程 BIM+gis 基础数据 全生命周期
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GIS扩建过程中连接母线的应力强度仿真分析
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作者 付威 蒋晓东 +1 位作者 彭澎 王闯 《高压电器》 北大核心 2025年第1期12-18,共7页
气体绝缘封闭开关(GIS)是广泛使用的电力设备,对现有GIS设备进行扩建是提高变电站输送能力的迫切需求。在GIS扩建过程中,连接母线承载着原设备及新设备之间的机械与电气连接,连接母线的稳定性是GIS正常运行的基本保障。文中设计了一种... 气体绝缘封闭开关(GIS)是广泛使用的电力设备,对现有GIS设备进行扩建是提高变电站输送能力的迫切需求。在GIS扩建过程中,连接母线承载着原设备及新设备之间的机械与电气连接,连接母线的稳定性是GIS正常运行的基本保障。文中设计了一种同水平位置布置的连接母线,并对母线在短路电流作用下的应力进行仿真分析。建立有限元模型,施加峰值为125 kA的短路电流负载,得到了150 ms内的应力时程曲线。结果表明母线各零件应力基本随时间呈先增大再减小趋势,应力最大值约在12~20 ms出现,螺栓处应力最大值显著大于导线处。母线两侧的盆式绝缘子主要受力点为三相导线镶嵌处,同时盆式绝缘子在短路电流最大相位置所受力矩最大。文中研究结果可对GIS扩建过程中连接母线的设计提供参考。 展开更多
关键词 gis 母线 盆式绝缘子 有限元仿真
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基于FME技术实现CAD与GIS数据共享的研究
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作者 谢亮 《科学技术创新》 2025年第1期108-111,共4页
为了促进CAD与GIS数据的高效共享与应用,本文介绍了利用FME技术进行数据转换的方法。首先,通过CAD数据预处理确保数据质量;随后,详细探讨了分层设色、要素符号与编码标准设计,为数据转换提供了标准依据。在此基础上,本文构建了GIS数据库... 为了促进CAD与GIS数据的高效共享与应用,本文介绍了利用FME技术进行数据转换的方法。首先,通过CAD数据预处理确保数据质量;随后,详细探讨了分层设色、要素符号与编码标准设计,为数据转换提供了标准依据。在此基础上,本文构建了GIS数据库,并通过语义映射技术实现了CAD与GIS数据的共享。最后,对共享数据进行了质量检查,确保了数据的准确性和可靠性。研究结果表明,利用FME技术可以有效实现CAD与GIS数据共享,为地理信息数据的集成与应用提供了有力支持。 展开更多
关键词 FME技术 CAD gis 数据 共享
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Three-dimensional visualization technology for guiding one-step percutaneous transhepatic cholangioscopic lithotripsy for the treatment of complex hepatolithiasis 被引量:2
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作者 Yong-Qing Ye Ya-Wen Cao +6 位作者 Rong-Qi Li En-Ze Li Lei Yan Zhao-Wei Ding Jin-Ming Fan Ping Wang Yi-Xiang Wu 《World Journal of Gastroenterology》 SCIE CAS 2024年第28期3393-3402,共10页
BACKGROUND Biliary stone disease is a highly prevalent condition and a leading cause of hospitalization worldwide.Hepatolithiasis with associated strictures has high residual and recurrence rates after traditional mul... BACKGROUND Biliary stone disease is a highly prevalent condition and a leading cause of hospitalization worldwide.Hepatolithiasis with associated strictures has high residual and recurrence rates after traditional multisession percutaneous transhepatic cholangioscopic lithotripsy(PTCSL).AIM To study one-step PTCSL using the percutaneous transhepatic one-step biliary fistulation(PTOBF)technique guided by three-dimensional(3D)visualization.METHODS This was a retrospective,single-center study analyzing,140 patients who,between October 2016 and October 2023,underwent one-step PTCSL for hepatolithiasis.The patients were divided into two groups:The 3D-PTOBF group and the PTOBF group.Stone clearance on choledochoscopy,complications,and long-term clearance and recurrence rates were assessed.RESULTS Age,total bilirubin,direct bilirubin,Child-Pugh class,and stone location were similar between the 2 groups,but there was a significant difference in bile duct strictures,with biliary strictures more common in the 3D-PTOBF group(P=0.001).The median follow-up time was 55.0(55.0,512.0)days.The immediate stone clearance ratio(88.6%vs 27.1%,P=0.000)and stricture resolution ratio(97.1%vs 78.6%,P=0.001)in the 3D-PTOBF group were significantly greater than those in the PTOBF group.Postoperative complication(8.6%vs 41.4%,P=0.000)and stone recurrence rates(7.1%vs 38.6%,P=0.000)were significantly lower in the 3D-PTOBF group.CONCLUSION Three-dimensional visualization helps make one-step PTCSL a safe,effective,and promising treatment for patients with complicated primary hepatolithiasis.The perioperative and long-term outcomes are satisfactory for patients with complicated primary hepatolithiasis.This minimally invasive method has the potential to be used as a substitute for hepatobiliary surgery. 展开更多
关键词 HEPATOLITHIASIS One-step percutaneous transhepatic cholangioscopic lithotripsy Biliary disease three-dimensional visualization Clinical efficacy
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Three-dimensional cell-based strategies for liver regeneration 被引量:1
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作者 DAN GUO XI XIA JIAN YANG 《BIOCELL》 SCIE 2024年第7期1023-1036,共14页
Liver regeneration and the development of effective therapies for liver failure remain formidable challenges in modern medicine.In recent years,the utilization of 3D cell-based strategies has emerged as a promising ap... Liver regeneration and the development of effective therapies for liver failure remain formidable challenges in modern medicine.In recent years,the utilization of 3D cell-based strategies has emerged as a promising approach for addressing these urgent clinical requirements.This review provides a thorough analysis of the application of 3D cell-based approaches to liver regeneration and their potential impact on patients with end-stage liver failure.Here,we discuss various 3D culture models that incorporate hepatocytes and stem cells to restore liver function and ameliorate the consequences of liver failure.Furthermore,we explored the challenges in transitioning these innovative strategies from preclinical studies to clinical applications.The collective insights presented herein highlight the significance of 3D cell-based strategies as a transformative paradigm for liver regeneration and improved patient care. 展开更多
关键词 three-dimensional Liver regeneration ORGANOIDS Stem cells Cell therapy
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基于组合赋权和GIS的雪崩灾害危险性评估
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作者 朱留魁 刘健 《科学技术创新》 2025年第1期25-28,共4页
采用组合赋权与地理信息系统(GIS)技术,对雪崩灾害的危险性进行了全面评估。首先,通过文献调研和实地考察,确定影响雪崩灾害发生的关键因素,包括气候、地形条件、以及其他相关因素;采用AHP和熵权法进行组合赋权确定综合权重,以反映各因... 采用组合赋权与地理信息系统(GIS)技术,对雪崩灾害的危险性进行了全面评估。首先,通过文献调研和实地考察,确定影响雪崩灾害发生的关键因素,包括气候、地形条件、以及其他相关因素;采用AHP和熵权法进行组合赋权确定综合权重,以反映各因素对雪崩灾害的不同影响程度;此外,利用GIS技术对综合权重进行空间分析和可视化表达,构建雪崩灾害危险性分布图。综合运用组合赋权和GIS技术,对禾木乡道X852线的雪崩灾害危险性进行有效评估。 展开更多
关键词 AHP 熵权法 组合赋权 gis 雪害评估
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Three-dimensional models:from cell culture to Patient-Derived Organoid and its application to future liposarcoma research
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作者 SAYUMI TAHARA SYDNEY RENTSCH +4 位作者 FERNANDA COSTAS CASAL DE FARIA PATRICIA SARCHET ROMA KARNA FEDERICA CALORE RAPHAEL E.POLLOCK 《Oncology Research》 SCIE 2025年第1期1-13,共13页
Liposarcoma is one of the most common soft tissue sarcomas,however,its occurrence rate is still rare compared to other cancers.Due to its rarity,in vitro experiments are an essential approach to elucidate liposarcoma ... Liposarcoma is one of the most common soft tissue sarcomas,however,its occurrence rate is still rare compared to other cancers.Due to its rarity,in vitro experiments are an essential approach to elucidate liposarcoma pathobiology.Conventional cell culture-based research(2D cell culture)is still playing a pivotal role,while several shortcomings have been recently under discussion.In vivo,mouse models are usually adopted for pre-clinical analyses with expectations to overcome the issues of 2D cell culture.However,they do not fully recapitulate human dedifferentiated liposarcoma(DDLPS)characteristics.Therefore,three-dimensional(3D)culture systems have been the recent research focus in the cell biology field with the expectation to overcome at the same time the disadvantages of 2D cell culture and in vivo animal models and fill in the gap between them.Given the liposarcoma rarity,we believe that 3D cell culture techniques,including 3D cell cultures/co-cultures,and Patient-Derived tumor Organoids(PDOs),represent a promising approach to facilitate liposarcoma investigation and elucidate its molecular mechanisms and effective therapy development.In this review,we first provide a general overview of 3D cell cultures compared to 2D cell cultures.We then focus on one of the recent 3D cell culture applications,Patient-Derived Organoids(PDOs),summarizing and discussing several PDO methodologies.Finally,we discuss the current and future applications of PDOs to sarcoma,particularly in the field of liposarcoma. 展开更多
关键词 Cell culture LIPOSARCOMA Patient-Derived Organoid(PDO) SPHEROID three-dimensional(3D)cell culture
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基于国产化GIS的深圳市CIM地下空间平台研究及探索
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作者 周丹 张会 《智能建筑与智慧城市》 2025年第1期16-18,共3页
文章围绕城市建设、运行和应急管理中的地下空间资源底数不清、隐蔽性强、可知不可见等难点和痛点,开展了地下空间多源异构数据管理、复杂数据空间表达等关键技术的研究,用于支撑信创环境下地下空间复杂场景的应用。在应用探索中,采用... 文章围绕城市建设、运行和应急管理中的地下空间资源底数不清、隐蔽性强、可知不可见等难点和痛点,开展了地下空间多源异构数据管理、复杂数据空间表达等关键技术的研究,用于支撑信创环境下地下空间复杂场景的应用。在应用探索中,采用了具有跨平台GIS内核的国产化Map GIS平台软件,构建了覆盖多端、安全可信的CIM地下空间平台框架,推进了深圳市地下“透明化”管理,提升了地下空间风险防控能力,为超大型城市的地下空间资产管理、应急管理、公共安全等方面提供应用案例参考。 展开更多
关键词 地下空间平台 CIM gis 国产化
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BIM+GIS技术在来宾西高速中应用探索
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作者 杨朝栋 梁承斌 +1 位作者 蒋志强 彭林峰 《价值工程》 2025年第1期43-45,共3页
BIM+GIS融合技术可以将地理信息与建筑信息模型结合起来形成三维可视化的环境,帮助工程项目进行路线选择、地形分析、生产调度和协同,具有非常显著的时间和成本优势。本文针对来宾西高速公路在建设中的应用场景,探索了BIM+GIS的关键技... BIM+GIS融合技术可以将地理信息与建筑信息模型结合起来形成三维可视化的环境,帮助工程项目进行路线选择、地形分析、生产调度和协同,具有非常显著的时间和成本优势。本文针对来宾西高速公路在建设中的应用场景,探索了BIM+GIS的关键技术应用,以期为同类工程项目提供参考借鉴。 展开更多
关键词 BIM gis 公路工程 红线分析 实时量测 720全景 路基土石方收方
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基于GIS的河南省洛宁县滑坡灾害易发性评价
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作者 何海洋 《中国水土保持》 2025年第1期81-85,共5页
洛宁县地处河南省西部山地丘陵区,地质构造复杂,加之近年来极端强降雨频发,滑坡灾害增多,造成了重大人员伤亡和经济损失,因此做好洛宁县滑坡灾害易发性分区可为科学防灾减灾提供数据支撑。基于ArcGIS空间分析获取研究区域高程、坡度、... 洛宁县地处河南省西部山地丘陵区,地质构造复杂,加之近年来极端强降雨频发,滑坡灾害增多,造成了重大人员伤亡和经济损失,因此做好洛宁县滑坡灾害易发性分区可为科学防灾减灾提供数据支撑。基于ArcGIS空间分析获取研究区域高程、坡度、坡向、岩组、降水量、土地利用类型和归一化植被指数共7个指标因子,采用信息量模型对研究区进行栅格叠加后,利用自然断点法将研究区信息量值划分为极低、低、中、高易发区,结果表明:滑坡主要分布在高程500~<750 m、坡度0°~<20°的区域,且绝大部分滑坡所处的地貌为起伏山地;高易发区面积为627.95 km^(2),占全县总面积的27.23%;评价模型精度经ROC曲线检验,AUC值为0.8034,说明基于GIS建立的信息量模型对洛宁县滑坡易发性评价效果良好。 展开更多
关键词 滑坡灾害 易发性评价 gis 信息量模型 洛宁县
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Development of a toroidal soft x-ray imaging system and application for investigating three-dimensional plasma on J-TEXT
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作者 赵传旭 李建超 +9 位作者 张晓卿 王能超 丁永华 杨州军 江中和 严伟 李杨波 毛飞越 任正康 the J-TEXT Team 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第3期94-99,共6页
A toroidal soft x-ray imaging(T-SXRI)system has been developed to investigate threedimensional(3D)plasma physics on J-TEXT.This T-SXRI system consists of three sets of SXR arrays.Two sets are newly developed and locat... A toroidal soft x-ray imaging(T-SXRI)system has been developed to investigate threedimensional(3D)plasma physics on J-TEXT.This T-SXRI system consists of three sets of SXR arrays.Two sets are newly developed and located on the vacuum chamber wall at toroidal positionsφof 126.4°and 272.6°,respectively,while one set was established previously atφ=65.50.Each set of SXR arrays consists of three arrays viewing the plasma poloidally,and hence can be used separately to obtain SXR images via the tomographic method.The sawtooth precursor oscillations are measured by T-SXRI,and the corresponding images of perturbative SXR signals are successfully reconstructed at these three toroidal positions,hence providing measurement of the 3D structure of precursor oscillations.The observed 3D structure is consistent with the helical structure of the m/n=1/1 mode.The experimental observation confirms that the T-SXRI system is able to observe 3D structures in the J-TEXT plasma. 展开更多
关键词 SXR imaging J-TEXT tokamak three-dimensional measurement MHD
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Three-dimensional structural models,evolution and petroleum geological significances of transtensional faults in the Ziyang area,central Sichuan Basin,SW China
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作者 TIAN Fanglei GUO Tonglou +6 位作者 HE Dengfa GU Zhanyu MENG Xianwu WANG Renfu WANG Ying ZHANG Weikang LU Guo 《Petroleum Exploration and Development》 SCIE 2024年第3期604-620,共17页
With drilling and seismic data of Transtensional(strike-slip)Fault System in the Ziyang area of the central Sichuan Basin,SW China plane-section integrated structural interpretation,3-D fault framework model building,... With drilling and seismic data of Transtensional(strike-slip)Fault System in the Ziyang area of the central Sichuan Basin,SW China plane-section integrated structural interpretation,3-D fault framework model building,fault throw analyzing,and balanced profile restoration,it is pointed out that the transtensional fault system in the Ziyang 3-D seismic survey consists of the northeast-trending F_(I)19 and F_(I)20 fault zones dominated by extensional deformation,as well as 3 sets of northwest-trending en echelon normal faults experienced dextral shear deformation.Among them,the F_(I)19 and F_(I)20 fault zones cut through the Neoproterozoic to Lower Triassic Jialingjiang Formation,presenting a 3-D structure of an“S”-shaped ribbon.And before Permian and during the Early Triassic,the F_(I)19 and F_(I)20 fault zones underwent at least two periods of structural superimposition.Besides,the 3 sets of northwest-trending en echelon normal faults are composed of small normal faults arranged in pairs,with opposite dip directions and partially left-stepped arrangement.And before Permian,they had formed almost,restricting the eastward growth and propagation of the F_(I)19 fault zone.The F_(I)19 and F_(I)20 fault zones communicate multiple sets of source rocks and reservoirs from deep to shallow,and the timing of fault activity matches well with oil and gas generation peaks.If there were favorable Cambrian-Triassic sedimentary facies and reservoirs developing on the local anticlinal belts of both sides of the F_(I)19 and F_(I)20 fault zones,the major reservoirs in this area are expected to achieve breakthroughs in oil and gas exploration. 展开更多
关键词 transtensional(strike-slip)fault three-dimensional structural model structural evolution petroleum geological significance Ziyang area Sichuan Basin
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Hyper accuracy three-dimensional virtual anatomical rainbow model facilitates surgical planning and safe selective clamping during robot-assisted partial nephrectomy
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作者 Francesco Ditonno Antonio Franco +8 位作者 Celeste Manfredi Daniele Amparore Enrico Checcucci Marco De Sio Alessandro Antonelli Cosimo De Nunzio Cristian Fiori Francesco Porpiglia Riccardo Autorino 《Asian Journal of Urology》 CSCD 2024年第4期660-665,共6页
Objective:To highlight the role of hyper accuracy three-dimensional(3D)reconstruction in facilitating surgical planning and guiding selective clamping during robot-assisted partial nephrectomy(RAPN).Methods:A transper... Objective:To highlight the role of hyper accuracy three-dimensional(3D)reconstruction in facilitating surgical planning and guiding selective clamping during robot-assisted partial nephrectomy(RAPN).Methods:A transperitoneal RAPN was performed in a 62-year-old male patient presenting with a 4 cm right anterior interpolar renal mass(R.E.N.A.L nephrometry score 7A).An abnormal vasculature was observed,with a single renal vein and two right renal arteries originating superiorly to the vein and anterior,when dividing in their segmental branches.According to the hyper accuracy 3D(HA3D^(®))rainbow model(MEDICS Srl,Turin,Italy),one branch belonging to one of the segmental arteries was feeding the tumor.This allowed for an accurate prediction of the area vascularized by each arterial branch.The 3D model was included in the intraoperative console view during the whole procedure,using the TilePro feature.A step-by-step explanation of the procedure is provided in the video attached to the present article.Results:The operative time was 90 min with a warm ischemia time on selective clamping of 13 min.Estimated blood loss was 180 mL.No intraoperative complication was encountered and no drain was placed at the end of the procedure.The patient was discharged on postoperative Day 2,without any early postoperative complications.The final pathology report showed a pathological tumor stage 1 clear cell renal cell carcinoma with negative surgical margins.Conclusion:The present study and the attached video illustrate the value of 3D rainbow model during the planning and execution of a RAPN with selective clamping.It shows how the surgeon can rely on this model to be more efficient by avoiding unnecessary surgical steps,and to safely adopt a“selective”clamping strategy that can translate in minimal functional impact. 展开更多
关键词 Hyper accuracy three-dimensional rainbow model Augmented reality Clear cell renal cell carcinoma Robot-assisted partial nephrectomy Selective clamping
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电力变压器和GIS设备安装调试技术研究
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作者 李德润 牛子孺 +1 位作者 代馨田 李志戈 《中国设备工程》 2025年第1期254-256,共3页
在电力系统构建及运维体系中,变压器及其相关装置的安装与调试环节占据着至关重要的地位。该环节的精确执行对于电网的安全性、可靠性和高效运行具有决定性影响。其重要性显而易见,任何微小的偏差或疏忽均可能对电力系统的整体性能造成... 在电力系统构建及运维体系中,变压器及其相关装置的安装与调试环节占据着至关重要的地位。该环节的精确执行对于电网的安全性、可靠性和高效运行具有决定性影响。其重要性显而易见,任何微小的偏差或疏忽均可能对电力系统的整体性能造成重大影响。因此,在实际操作过程中,必须严格遵守既定的安装程序和技术规范,确保各步骤的精确性。同时,为确保装置在投入运行后能够持续稳定、可靠地工作,必须满足电力系统相关的工作规范和安装规程。本文对变压器及GIS设备的安装、调试等技术细节进行了深入探讨,目的在于通过细致的研究与分析,揭示其技术关键点与难点,为电力系统的安全稳定运行提供坚实的技术支撑。本研究不仅具有显著的理论价值,而且对电力系统的实际运维工作具有重要的指导意义。 展开更多
关键词 电力变压器 气体绝缘金属封闭开关设备(gis) 安装与调试
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Three-dimensional(3D)parametric measurements of individual gravels in the Gobi region using point cloud technique
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作者 JING Xiangyu HUANG Weiyi KAN Jiangming 《Journal of Arid Land》 SCIE CSCD 2024年第4期500-517,共18页
Gobi spans a large area of China,surpassing the combined expanse of mobile dunes and semi-fixed dunes.Its presence significantly influences the movement of sand and dust.However,the complex origins and diverse materia... Gobi spans a large area of China,surpassing the combined expanse of mobile dunes and semi-fixed dunes.Its presence significantly influences the movement of sand and dust.However,the complex origins and diverse materials constituting the Gobi result in notable differences in saltation processes across various Gobi surfaces.It is challenging to describe these processes according to a uniform morphology.Therefore,it becomes imperative to articulate surface characteristics through parameters such as the three-dimensional(3D)size and shape of gravel.Collecting morphology information for Gobi gravels is essential for studying its genesis and sand saltation.To enhance the efficiency and information yield of gravel parameter measurements,this study conducted field experiments in the Gobi region across Dunhuang City,Guazhou County,and Yumen City(administrated by Jiuquan City),Gansu Province,China in March 2023.A research framework and methodology for measuring 3D parameters of gravel using point cloud were developed,alongside improved calculation formulas for 3D parameters including gravel grain size,volume,flatness,roundness,sphericity,and equivalent grain size.Leveraging multi-view geometry technology for 3D reconstruction allowed for establishing an optimal data acquisition scheme characterized by high point cloud reconstruction efficiency and clear quality.Additionally,the proposed methodology incorporated point cloud clustering,segmentation,and filtering techniques to isolate individual gravel point clouds.Advanced point cloud algorithms,including the Oriented Bounding Box(OBB),point cloud slicing method,and point cloud triangulation,were then deployed to calculate the 3D parameters of individual gravels.These systematic processes allow precise and detailed characterization of individual gravels.For gravel grain size and volume,the correlation coefficients between point cloud and manual measurements all exceeded 0.9000,confirming the feasibility of the proposed methodology for measuring 3D parameters of individual gravels.The proposed workflow yields accurate calculations of relevant parameters for Gobi gravels,providing essential data support for subsequent studies on Gobi environments. 展开更多
关键词 Gobi gravels three-dimensional(3D)parameters point cloud 3D reconstruction Random Sample Consensus(RANSAC)algorithm Density-Based Spatial Clustering of Applications with Noise(DBSCAN)
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应用GIS模糊层次分析法对森林火灾风险区划——以湖南省宁远县为例
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作者 陈国富 《东北林业大学学报》 CAS 北大核心 2025年第2期114-121,151,共9页
应用ArcGIS的模糊逻辑和层次分析法,对湖南省宁远县的森林火灾风险进行评估和火险区划研究,参与评估的火险因子包括环境、人类活动和地形因子。研究结果表明:温度、降水、海拔和归一化植被指数(NDVI)对研究区域林火风险的影响最为显著;... 应用ArcGIS的模糊逻辑和层次分析法,对湖南省宁远县的森林火灾风险进行评估和火险区划研究,参与评估的火险因子包括环境、人类活动和地形因子。研究结果表明:温度、降水、海拔和归一化植被指数(NDVI)对研究区域林火风险的影响最为显著;宁远县47.6%的区域被确定为四级及以上火险等级,主要分布于该县中部的大部分地区,该县火险情况严峻;编制的森林火灾风险图预测精度达82.7%。模糊层次分析法在森林火灾风险预测中展现出较好的效果,可作为林火预测和火险制图的重要工具,编制的森林火灾风险图为宁远县的林火管理提供了科学参考依据。 展开更多
关键词 森林火灾 火险区划 地理信息系统 多准则决策分析 模糊层次分析法
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Temporal Three-Dimensional Ontology for Geographical Information Science (GIS)—A Review 被引量:1
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作者 Uznir Ujang Alias Abdul Rahman 《Journal of Geographic Information System》 2013年第3期314-323,共10页
While the use of three-dimensional (3D) geographical information system (GIS) is becoming in rapid development and being used in various fields such as urban and regional planning, disaster management and planning, mo... While the use of three-dimensional (3D) geographical information system (GIS) is becoming in rapid development and being used in various fields such as urban and regional planning, disaster management and planning, mobile navigation and etc., commercial and open source GIS software packages tend to offer 3D-GIS functionalities for their products. On the basis, GIS analysis functions are to provide information with respect to geographical location and by having 3D spatial data as an input, it will give advantages in providing horizontal position information. However, to analyze moving objects (temporal) in 3D seems not an easy task and not fully supported by current GIS platform packages. Previously in two-dimensional (2D) GIS practice, main issue addressed by researchers in managing temporal spatial objects is GIS packages were designed based on hardware and software constraints whereby it should be based on the temporal spatial objects ontology. Nowadays, the trend of managing temporal 3D data is via 3D spatial simulation or animation. This approach will not in assistance for GIS users in conducting spatial queries. Without having a suitable ontology and valid topological data structure for temporal 3D data, it will cause repetitive of temporal data (redundancy) and complications in executing spatial analysis in 3D environment. Therefore this paper focuses on the ontology for managing moving 3D spatial objects (i.e. air pollution, flood). The characteristics of moving objects were reviewed thoroughly by categorizing it based on its different appearances. Moreover, existing methods in managing temporal database were addressed and discussed for its practicalities. Another important aspect in managing temporal 3D objects is the implementation of topological data structures for 3D spatial objects were reviewed. In the last section of this paper it summarized the issues and further ideas towards implementing and managing temporal 3D spatial objects in GIS based on the Geoinformation Ontology (GeO). 展开更多
关键词 MULTIDIMENSIONAL gis TEMPORAL gis Geoinformation ONTOLOGY 3D gis 3D CITY Modeling
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GIS-based Numerical Modelling of Debris Flow Motion across Three-dimensional Terrain 被引量:2
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作者 WU Jian CHEN Guang-qi +1 位作者 ZHENG Lu ZHANG Ying-bin 《Journal of Mountain Science》 SCIE CSCD 2013年第4期522-531,共10页
The objective of this study is to incorporate a numerical model with GIS to simulate the movement, erosion and deposition of debris flow across the three dimensional complex terrain. In light of the importance of eros... The objective of this study is to incorporate a numerical model with GIS to simulate the movement, erosion and deposition of debris flow across the three dimensional complex terrain. In light of the importance of erosion and deposition processes during debris flow movement, no entrainment assumption is unreasonable. The numerical model considering these processes is used for simulating debris flow. Raster grid networks of a digital elevation model in GIS provide a uniform grid system to describe complex topography. As the raster grid can be used as the finite difference mesh, the numerical model is solved numerically using the Leap-frog finite difference method. Finally, the simulation results can be displayed by GIS easily and used to debris flow evaluation. To illustrate this approach, the proposed methodology is applied to the Yohutagawa debris flow that occurred on 2oth October 2010, in Amami- Oshima area, Japan. The simulation results that reproduced the movement, erosion and deposition are in good agreement with the field investigation. The effectiveness of the dam in this real-ease is also verified by this approach. Comparison with the results were simulated by other models, shows that the present coupled model is more rational and effective. 展开更多
关键词 Debris flow Numerical simulation gis MOVEMENT EROSION DEPOSITION Equilibriumconcentration
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