Motion simulator usually appears the phenomenon of false cues and the workspace is limited in the process of washout. The proposed washout algorithm combines fuzzy logic control with the vestibular system to design th...Motion simulator usually appears the phenomenon of false cues and the workspace is limited in the process of washout. The proposed washout algorithm combines fuzzy logic control with the vestibular system to design the tilt coordination fuzzy adaptive filter, in order to minimize the vestibular sensory error below the human perception threshold. Owing to tilt coordination angular velocity limiter, the loss of low-pass acceleration must be compensated by the acceleration transform model. The translational channel decreases the possibility of the workspace beyond limitation and expands the scope of motion platform simulating input acceleration by using third-order filter. The simulation results show that the proposed algorithm can effectively overcome the phase retardation of classical washout algorithm, and then prevent the produce of false cues, decrease the displacement of motion platform simultaneously; in addition, white Gaussian noise simulates large variations in acceleration. The proposed washout algorithm can have maximal extreme value of acceleration and accurate simulating performance in general. It also proves that the proposed washout algorithm has a strong adaptability and reliability, which can effectively improve the dynamic fidelity for motion simulator.展开更多
Animals’ regional femur blood (F) alteration was studied under an inadequate decompression by using the inhaled isotope 133Xe washout method. Results showed that the average F on left and right side of minipigs’ fem...Animals’ regional femur blood (F) alteration was studied under an inadequate decompression by using the inhaled isotope 133Xe washout method. Results showed that the average F on left and right side of minipigs’ femur decreased from 15.4±1.8 and 16 .9±2.0 ml/ (100 g.min) (before exposure) to 10±1.8 and 11.1±1.6 ml/(100mg.min) (after expposure for 1.5 h under the pressure of 0.5 MPa and then decompression to normal with the rate of 0.03~0.04MPa/min), respectively; the blood flow of hematopoietic marrow tissues (f1)on both sides also decreased from 19.3±2.0 and 22.1±1.9 ml/(100mg.min) to 13.9±1.4 and 13.8±1.0 ml/(100 mg.min). The exact same alteration also happened in the experiment on New Zealand rabbits. It indicates that inadequate decompression in hyperbaric exposure can give rise to decrease animals’ bone blood flow and insufficient bone blood supply serves as one of the reasons for causing decompressive osteonecrosis.展开更多
背景使用行政管理数据时,确立清晰、适当的慢性病洗脱期时长是正确确定反复就医的慢性病患者发病时点、确定新发病例的基础。目的通过系统文献回顾,综述确定洗脱期时长的方法,以期为我国研究者后续使用行政管理数据识别慢性病新发病例...背景使用行政管理数据时,确立清晰、适当的慢性病洗脱期时长是正确确定反复就医的慢性病患者发病时点、确定新发病例的基础。目的通过系统文献回顾,综述确定洗脱期时长的方法,以期为我国研究者后续使用行政管理数据识别慢性病新发病例时确认洗脱期长短、正确识别新发病例提供思路。方法于2021年10月,系统检索PubMed、Web of Science、EmBase、中国知网、维普中文科技期刊全文数据库、万方知识服务平台,获取有关利用行政管理数据探究慢性病发病、患病情况的文献,检索时限均为建库至2022-10-01。由两名研究者独立筛选文献并提取相关信息,并采用定性研究报告评价标准(SRQR)评价文献方法学质量后,使用描述性分析法总结洗脱期时长的确定方法。结果共纳入26篇文献,纳入文献的SRQR评分均≥15分,方法学质量较好。文献所使用的数据主要来自加拿大、美国、澳大利亚等行政管理数据完整、丰富的国家(地区),聚焦的疾病包括糖尿病、肿瘤、精神分裂症等多种慢性病。研究指出,设定合适的洗脱期时长是准确识别发病病例的基础。目前,文献中确定洗脱期时长的方法主要包括直接限定法、一致性检验法和逆向生存函数法三大类,其中最常用的方法是直接限定法,逆向生存曲线法的使用率相对较低。结论直接限定法、一致性检验法和逆向生存函数法均有相应的优势和局限性,方法的选择标准、判断标准和稳定性有待进一步探究。展开更多
基金Funded by the National Natural Science Foundation of China(U1233107)Civil Aviation Science and Technology Innovation Project of China(MHRD20140210)
文摘Motion simulator usually appears the phenomenon of false cues and the workspace is limited in the process of washout. The proposed washout algorithm combines fuzzy logic control with the vestibular system to design the tilt coordination fuzzy adaptive filter, in order to minimize the vestibular sensory error below the human perception threshold. Owing to tilt coordination angular velocity limiter, the loss of low-pass acceleration must be compensated by the acceleration transform model. The translational channel decreases the possibility of the workspace beyond limitation and expands the scope of motion platform simulating input acceleration by using third-order filter. The simulation results show that the proposed algorithm can effectively overcome the phase retardation of classical washout algorithm, and then prevent the produce of false cues, decrease the displacement of motion platform simultaneously; in addition, white Gaussian noise simulates large variations in acceleration. The proposed washout algorithm can have maximal extreme value of acceleration and accurate simulating performance in general. It also proves that the proposed washout algorithm has a strong adaptability and reliability, which can effectively improve the dynamic fidelity for motion simulator.
文摘Animals’ regional femur blood (F) alteration was studied under an inadequate decompression by using the inhaled isotope 133Xe washout method. Results showed that the average F on left and right side of minipigs’ femur decreased from 15.4±1.8 and 16 .9±2.0 ml/ (100 g.min) (before exposure) to 10±1.8 and 11.1±1.6 ml/(100mg.min) (after expposure for 1.5 h under the pressure of 0.5 MPa and then decompression to normal with the rate of 0.03~0.04MPa/min), respectively; the blood flow of hematopoietic marrow tissues (f1)on both sides also decreased from 19.3±2.0 and 22.1±1.9 ml/(100mg.min) to 13.9±1.4 and 13.8±1.0 ml/(100 mg.min). The exact same alteration also happened in the experiment on New Zealand rabbits. It indicates that inadequate decompression in hyperbaric exposure can give rise to decrease animals’ bone blood flow and insufficient bone blood supply serves as one of the reasons for causing decompressive osteonecrosis.
文摘背景使用行政管理数据时,确立清晰、适当的慢性病洗脱期时长是正确确定反复就医的慢性病患者发病时点、确定新发病例的基础。目的通过系统文献回顾,综述确定洗脱期时长的方法,以期为我国研究者后续使用行政管理数据识别慢性病新发病例时确认洗脱期长短、正确识别新发病例提供思路。方法于2021年10月,系统检索PubMed、Web of Science、EmBase、中国知网、维普中文科技期刊全文数据库、万方知识服务平台,获取有关利用行政管理数据探究慢性病发病、患病情况的文献,检索时限均为建库至2022-10-01。由两名研究者独立筛选文献并提取相关信息,并采用定性研究报告评价标准(SRQR)评价文献方法学质量后,使用描述性分析法总结洗脱期时长的确定方法。结果共纳入26篇文献,纳入文献的SRQR评分均≥15分,方法学质量较好。文献所使用的数据主要来自加拿大、美国、澳大利亚等行政管理数据完整、丰富的国家(地区),聚焦的疾病包括糖尿病、肿瘤、精神分裂症等多种慢性病。研究指出,设定合适的洗脱期时长是准确识别发病病例的基础。目前,文献中确定洗脱期时长的方法主要包括直接限定法、一致性检验法和逆向生存函数法三大类,其中最常用的方法是直接限定法,逆向生存曲线法的使用率相对较低。结论直接限定法、一致性检验法和逆向生存函数法均有相应的优势和局限性,方法的选择标准、判断标准和稳定性有待进一步探究。
