Let ε ： y^2 = x3 ＋ Ax ＋ B be an elliptic curve defined over the finite field Zp（p 〉 3） and G be a rational point of prime order N on ε. Define a subset of ZN, the residue class ring modulo N, asS：={n：n∈ZN,n...Let ε ： y^2 = x3 ＋ Ax ＋ B be an elliptic curve defined over the finite field Zp（p 〉 3） and G be a rational point of prime order N on ε. Define a subset of ZN, the residue class ring modulo N, asS：={n：n∈ZN,n≠0,（X（nG）/p）=1} where X（nG） denotes the x-axis of the rational points nC and （＊/P） is the Legendre symbol. Some explicit results on quasi-randomness of S are investigated. The construction depends on the intrinsic group structures of elliptic curves and character sums along elliptic curves play an important role in the proofs.展开更多
We study the quasi-random choice method （QRCM） for the Liouville equation of ge- ometrical optics with discontinuous locM wave speed. This equation arises in the phase space computation of high frequency waves throu...We study the quasi-random choice method （QRCM） for the Liouville equation of ge- ometrical optics with discontinuous locM wave speed. This equation arises in the phase space computation of high frequency waves through interfaces, where waves undergo partial transmissions and reflections. The numerical challenges include interface, contact discon- tinuities, and measure-valued solutions. The so-called QRCM is a random choice method based on quasi-random sampling （a deterministic alternative to random sampling）. The method not only is viscosity-free but also provides faster convergence rate. Therefore, it is appealing for the prob!em under study which is indeed a Hamiltonian flow. Our analy- sis and computational results show that the QRCM 1） is almost first-order accurate even with the aforementioned discontinuities; 2） gives sharp resolutions for all discontinuities encountered in the problem; and 3） for measure-valued solutions, does not need the level set decomposition for finite difference/volume methods with numerical viscosities.展开更多
目的系统评价冬虫夏草治疗慢性阻塞性肺疾病的临床疗效。方法计算机检索CBM、CNKI、WanFang Data、VIP、PubMed、Cochrane Central Register of Controlled Trials(2013年第7期)以及EMbase,查找天然虫草或人工虫草制剂治疗慢性阻塞性肺...目的系统评价冬虫夏草治疗慢性阻塞性肺疾病的临床疗效。方法计算机检索CBM、CNKI、WanFang Data、VIP、PubMed、Cochrane Central Register of Controlled Trials(2013年第7期)以及EMbase,查找天然虫草或人工虫草制剂治疗慢性阻塞性肺疾病的随机或半随机对照试验。按照Cochrane系统评价方法筛选文献、提取资料并评价质量后,采用RevMan 5.2软件进行Meta分析。结果共纳入14个半随机对照试验,1 162例患者。Meta分析结果显示:①人工虫草制剂+常规治疗组的总有效率优于常规治疗组[稳定期RR=1.33,95%CI(1.14,1.54),P=0.000 3;急性期RR=1.36,95%CI(1.14,1.62),P=0.000 8]。人工虫草制剂+常规治疗组对稳定期患者的肺功能指标FEV1/FVC[MD=5.48,95%CI(3.22,7.74),P<0.000 01]、FEV1%[MD=3.75,95%CI(0.91,6.59),P=0.010]以及6分钟步行试验[MD=43.51,95%CI(27.66,59.36),P<0.000 01]均有较好的改善作用。但尚缺乏报告血气分析、免疫功能和生存质量的研究,以及对急性期患者各项指标的报告。②1个研究结果显示,人工虫草制剂+常规治疗组与斯奇康+常规治疗组的总有效率无明显差异,前者的肺功能有更好的改善。结论现有证据表明,人工虫草制剂治疗慢性阻塞性肺疾病有一定效果,尤其可改善稳定期患者的肺功能和运动耐力,提高治疗总有效率。但纳入研究质量低,影响了合并结果的论证强度。今后尚需进一步开展高质量、大样本的临床研究验证其临床效果。展开更多
基金Supported by the National Natural Science Foundation of China(No.61170246)the Program for New Century Excellent Talents in Fujian Province University of China(No.JK2010047)the Open Funds of State Key Laboratory of Information Security (Chinese Academy of Sciences)(No.01-01-1)
文摘Let ε ： y^2 = x3 ＋ Ax ＋ B be an elliptic curve defined over the finite field Zp（p 〉 3） and G be a rational point of prime order N on ε. Define a subset of ZN, the residue class ring modulo N, asS：={n：n∈ZN,n≠0,（X（nG）/p）=1} where X（nG） denotes the x-axis of the rational points nC and （＊/P） is the Legendre symbol. Some explicit results on quasi-randomness of S are investigated. The construction depends on the intrinsic group structures of elliptic curves and character sums along elliptic curves play an important role in the proofs.
文摘We study the quasi-random choice method （QRCM） for the Liouville equation of ge- ometrical optics with discontinuous locM wave speed. This equation arises in the phase space computation of high frequency waves through interfaces, where waves undergo partial transmissions and reflections. The numerical challenges include interface, contact discon- tinuities, and measure-valued solutions. The so-called QRCM is a random choice method based on quasi-random sampling （a deterministic alternative to random sampling）. The method not only is viscosity-free but also provides faster convergence rate. Therefore, it is appealing for the prob!em under study which is indeed a Hamiltonian flow. Our analy- sis and computational results show that the QRCM 1） is almost first-order accurate even with the aforementioned discontinuities; 2） gives sharp resolutions for all discontinuities encountered in the problem; and 3） for measure-valued solutions, does not need the level set decomposition for finite difference/volume methods with numerical viscosities.
基金supported by the Joint Fund of the State Key Laboratory of Coal Resources and Safe Mining-Beijing University Outstanding Young Scientists Program Project (BJJWZYJH01201911413037)State Key Laboratory of“Coal Resources and Safe Mining”Open Fund (SKLCRSM19ZZ02)。
