Results 31 to 40 of about 17,002 (171)
体表光学图像引导技术联合图像引导放疗技术等中心双引导复位在乳腺癌调强放疗中的应用
Zhongshan Daxue xuebao. Yixue kexue ban, 2023 目的探讨体表光学图像引导技术（SGRT）联合图像引导放疗技术（IGRT）在乳腺癌术后放疗中实施等中心双引导复位的可行性，评估新的复位模式相对于传统复位模式的误差精度差异。方法回顾性分析2021年7月13日至2022年10月15日在中山大学肿瘤防治中心ELEKTA infinity加速器放疗的乳腺癌保乳术后患者，按不同复位方式分为模拟机复位组（模拟组）41例和双引导复位组（双引导组）40例。模拟组采用模拟机进行复位，首次用CBCT扫描并记录摆位误差 ...
陈雪梅 +7 more
doaj
Latin American Policy, Volume 16, Issue 2, June 2025.ABSTRACT This study examines the effects of the Covid‐19 pandemic on preexisting cash transfers and labor programs across Latin America, analyzing their temporal expansion and identifying the determinants of changes in their generosity and coverage, with a particular focus on the inclusion of informal workers.
Luis Vargas‐Faulbaum +2 more
wiley +1 more source
基于高斯混合模型 Varian NovalisTX 直线加速器盆腔肿瘤放疗摆位误差分布预测模型的构建
Zhongshan Daxue xuebao. Yixue kexue ban, 2019 【目的】构建 Varian NovalisTX 直线加速器盆腔肿瘤放疗摆位误差分布预测模型。【方法】选取加速器 治 疗 30 例 盆 腔 肿 瘤 患 者 先 验 IGRT 摆 位 误 差 数 据 ，采 用 高 斯 混 合 模 型 构 建 误 差 分 布 预 测 模 型 ，并 求 解 分 析 模 型 参数。【结果】由模型参数可知摆位误差主要往μ1~μ4 四个中心点方向集中；中心点坐标表明误差在 Vrt 方向（-3.88~4.28）mm 和 Lng 方 向（-2.41~1.54）mm 较 大 ，Lat 方 ...
丘敏敏 +4 more
doaj
六维床在头、胸、腹部肿瘤常规直线加速器放射治疗中的摆位误差回顾性分析
Fushe yanjiu yu fushe gongyi xuebao回顾性分析基于加速器六维床摆位的肿瘤患者的CBCT（Cone-Beam CT，CBCT）图像，比较患者的摆位误差数据，分析肿瘤患者六维床放射治疗中分次内摆位误差的数据，研究六维床对不同位置肿瘤产生的摆位效果差异。选取2020年3月至2023年9月于本中心接受放疗的肿瘤患者85例，分成脑瘤、肺癌、直肠癌和乳腺癌。统计4组患者在左右、头脚、腹背6个自由度（X、Y、Z和Rx、Ry、Rz）的首次和分次内摆位误差。采用双样本异方差t检验对比分析不同瘤种在各个方向上的分次内摆位误差 ...
万 宝 +8 more
doaj +1 more source
基于数据相关性分析的全光纤电流互感器误差状态在线评估方法研究
Gaoya dianqi, 2022 全光纤电流互感器是特高压输电系统中电流测量的关键设备，复杂的物理结构导致其测量误差易受多种因素的影响，稳定性较差。常规的误差检测方法是定期利用标准互感器进行比对测试，无法及时发现误差状态的劣化趋势，且经济性较差。针对这一问题，文中提出了一种基于相关性分析的全光纤电流互感器误差状态评估方法：采集换流站同一测量点下三台全光纤电流互感器的测量数据，在电气物理相关性的约束下，针对全光纤电流互感器的测量数据进行主元分形，将误差评估映射为Q统计量的变化分析。数据分析表明 ...
叶剑涛 +5 more
doaj
Ultrasound in Obstetrics &Gynecology, Volume 65, Issue 5, Page 624-632, May 2025.ABSTRACT Objectives Placental insufficiency contributes to many obstetric pathologies, but there is no bedside clinical tool to evaluate placental perfusion. We have developed a method to acquire multiple three‐dimensional (3D) power Doppler (PD) ultrasound (US) volumes of placental vasculature, with infrared camera tracking of the precise spatial ...
A. Xue +5 more
wiley +1 more source
Landscape‐scale predictions of future grassland conversion to cropland or development
Conservation Biology, Volume 39, Issue 1, February 2025.Abstract Grassland conservation planning often focuses on high‐risk landscapes, but many grassland conversion models are not designed to optimize conservation planning because they lack multidimensional risk assessments and are misaligned with ecological and conservation delivery scales.
Kevin W. Barnes +2 more
wiley +1 more source
World Medical &Health Policy, Volume 16, Issue 4, Page 547-557, December 2024.Abstract We evaluate the effect of the recent spate of tax reform laws on cigarette and fermented liquor consumption in the Philippines using an error correction model that utilizes regularly available national data. Since 2012, the Philippine government passed three reform measures that substantially increases cigarette and alcohol excise taxes to ...
Rutcher M. Lacaza +1 more
wiley +1 more source
TELESIS error matrixes correction of BESII(北京谱仪Ⅱ TELESIS误差矩阵的修正)
Zhejiang Daxue xuebao. Lixue ban, 2002 借鉴北京谱议Ⅱ第1批27×106J/ψ数据带电径迹和中性径迹误差矩阵修正的方法,选取J/ψ衰变到μ+μ- 和辐射e+e-过程的数据样本,研究了北京谱议Ⅱ第2批数据误差矩阵的修正:(1)利用J/ψ→μ+μ-样本,对带电径迹完成了RUN-by-RUN误差矩阵刻度.(2) 利用J/ψ→γe+e-样本,在0.2～1.4 GeV能量范围内,完成了桶部簇射计数器(BSC)中对中性径迹的沉积能量和空间位置测量的误差矩阵修正.经上述误差矩阵修正后,北京谱议Ⅱ的TELESIS可以较好地满足J/ψ数据分析工作的进一步要求.
YUANJian-ming(袁建明) +2 more
doaj +1 more source
Methods in Ecology and Evolution, Volume 15, Issue 10, Page 1757-1763, October 2024.Abstract Large language models (LLMs) are a type of artificial intelligence (AI) that can perform various natural language processing tasks. The adoption of LLMs has become increasingly prominent in scientific writing and analyses because of the availability of free applications such as ChatGPT. This increased use of LLMs not only raises concerns about
Natalie Cooper +4 more
wiley +1 more source