为了解决Duval Pentagon1法不能表征各种变压器故障模式可信度的问题,提出了一种基于空间分析理论改进的方法。首先,采用核密度估计(kernel density estimation,KDE)方法对各种变压器故障模式数据进行空间分布密度分析;其次,应用B样条...为了解决Duval Pentagon1法不能表征各种变压器故障模式可信度的问题,提出了一种基于空间分析理论改进的方法。首先,采用核密度估计(kernel density estimation,KDE)方法对各种变压器故障模式数据进行空间分布密度分析;其次,应用B样条理论构造各种变压器故障模式密度曲面;最后,利用空间叠置分析方法实现变压器故障模式识别。实例分析结果表明:与Duval Pentagon1法相比,改进后的Duval Pentagon1法的总体诊断准确率提升了8.42%,并且能够定量地表征各种变压器故障模式可信度。研究结果可为变压器油中溶解气体图形分析方法的改进提供参考。展开更多
Yolk sac tumors of the ovary are rare entities that account for 2% - 5% of all ovarian tumors. They represent the second most common histological variant of malignant germ cell tumors of the ovary after dysgerminomas....Yolk sac tumors of the ovary are rare entities that account for 2% - 5% of all ovarian tumors. They represent the second most common histological variant of malignant germ cell tumors of the ovary after dysgerminomas. Yolk sac tumors are most commonly encountered in women in the second and third decades. Microscopically, they are highly polymorphic and can present in a pure form or associated with another contingent of germ cell tumor. We report the case of a 26-year-old woman, who underwent surgery for a large right ovarian tumor rupturing into the peritoneal cavity. The ovarian tumor was revealed by ascites of great abundance and abdomino-pelvic pain. On histological examination, the diagnosis of yolk sac tumor in its pure and polyvesicular vitelline pattern was made. Through this observation, we propose to discuss the anatomoclinical particularities of these tumors by emphasizing the importance of histology for the diagnosis as well as the need of an early and appropriate management.展开更多
文摘Yolk sac tumors of the ovary are rare entities that account for 2% - 5% of all ovarian tumors. They represent the second most common histological variant of malignant germ cell tumors of the ovary after dysgerminomas. Yolk sac tumors are most commonly encountered in women in the second and third decades. Microscopically, they are highly polymorphic and can present in a pure form or associated with another contingent of germ cell tumor. We report the case of a 26-year-old woman, who underwent surgery for a large right ovarian tumor rupturing into the peritoneal cavity. The ovarian tumor was revealed by ascites of great abundance and abdomino-pelvic pain. On histological examination, the diagnosis of yolk sac tumor in its pure and polyvesicular vitelline pattern was made. Through this observation, we propose to discuss the anatomoclinical particularities of these tumors by emphasizing the importance of histology for the diagnosis as well as the need of an early and appropriate management.
