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991.
Multifractal analysis of surface EMG signals for assessing muscle fatigue during static contractions 总被引:1,自引:0,他引:1
WANG Gang REN Xiao-mei LI Lei WANG Zhi-zhong 《浙江大学学报(A卷英文版)》2007,8(6):910-915
This study is aimed at assessing muscle fatigue during a static contraction using multifractal analysis and found that the surface electromyographic (SEMG) signals characterized multiffactality during a static contraction. By applying the method of direct determination ofthef(a) singularity spectrum, the area of the multifractal spectrum of the SEMG signals was computed. The results showed that the spectrum area significantly increased during muscle fatigue. Therefore the area could be used as an assessor of muscle fatigue. Compared with the median frequency (MDF)--the most popular indicator of muscle fatigue, the spectrum area presented here showed higher sensitivity during a static contraction. So the singularity spectrum area is considered to be a more effective indicator than the MDF for estimating muscle fatigue. 相似文献
992.
The yeast strain (Y18) was isolated from a soil sample collected from Fildes Peninsula, Antarctica. The strain is a psychrophilic yeast with optimum and maximum growth temperatures of 10 ℃ and 18 ℃, respectively. Teliospores were formed after 7 d on malt agar, when the germination of teliospores was observed. Both inositol and D-glucuronate were assimilated. Positive results of the DBB (diazonium blue B) color reaction, urease test, and starch formation were observed. The major CoQ is Qs. All results indicated that Y18 belongs to the genes of Mrakia. The 18S rDNA sequence analyses showed that Y18 is closely related to Mrakiafrigida. DNA-DNA relatedness study, and some biochemistry characteristics indicated that Y18 represents a new species for which Mrakia psychrophila sp. nov. is proposed. 相似文献
993.
Genetic analysis of fruit shape traits at different maturation stages in sponge gourd 总被引:5,自引:0,他引:5
The fruit shape is important quantitative trait closely related to the fruit quality. However, the genetic model of fruit shapes has not been proposed. Therefore, in the present study, analysis of genetic effects for fruit shape traits (fruit length and fruit perimeter) in sponge gourd was conducted by employing a developmental genetic model including fruit direct effects and maternal effects. Analysis approaches of unconditional and conditional variances were applied to evaluate the genetic behavior of fruit shape traits at economical and physiological maturation times. The results of variance analysis indicated that fruit length and fruit perimeter were simultaneously affected by fruit direct genetic effects and maternal effects. Fruit direct genetic effects were relatively more important for fruit shape traits at whole developmental period. The gene expression was most active at the economical maturation stage (1-12 d after flowering) for two shape traits, and the activation of gene was mostly due to direct dominance effects at physiological maturation stage (13-60 datter flowering). The coefficients due to different genetic effects, as well as the phenotypic correlation coefficients, varied significantly between fruit shape traits themselves at various maturation stages. The results showed that it was relatively easy to improve fruit shape traits for industrial purpose by carefully selecting the parents at economical maturation stage instead of that at physiological maturation stage. 相似文献
994.
995.
MENG Qing-xuan 《浙江大学学报(A卷英文版)》2007,8(6):932-938
Corporate restructuring was identified as a new industrial force that has great impact on economic values and that therefore has become central in daily financial decision making. This article investigates the optimal restructuring strategies under different dynamic factors and their numerous impacts on firm value. The concept of quasi-leverage is introduced and valuation models are built for corporate debt and equity under imperfect market conditions. The model's input variables include the quasi-leverage and other firm-specific parameters, the output variables include multiple corporate security values. The restructuring cost is formulated in the form of exponential function, which allows us to observe the sensitivity of the variation in security values. The unified model and its analytical solution developed in this research allow us to examine the continuous changes of security values by dynamically changing the coupon rates, riskless interest rate, bankruptcy cost, quasi-leverage, personal tax rate, corporate taxes rate, transaction cost, firm risk, etc., so that the solutions provide useful guidance for financing and restructuring decisions. 相似文献
996.
HAN Jing-wei YU Yao-yong 《浙江大学学报(A卷英文版)》2007,8(6):963-968
In this work, we study the Asanov Finsler metric F=α(β2/α2 gβ/α 1)1/2exp{(G/2)arctan[β/(hα) G/2]}, where α=(αijyiyj)1/2 is a Riemannian metric and β=biyj is a 1-form, g∈(-2,2), h=(1-g2/4)1/2, G=g/h. We give the necessary and sufficient condition for Asanov metric to be locally projectively flat, i.e., α is projectively flat and β is parallel with respect to α. Moreover, we proved that the Douglas tensor of Asanov Finsler metric vanishes if and only if β is parallel with respect to α. 相似文献
997.
In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P(S) ∝ e^-αs' where S represents nucleotide cluster size. The cluster-size distribution P(S1+S2) with the total size of sequential C-G cluster and A-T cluster S1+S2 were also studied. P(S1+S2) follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L(n) and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence. 相似文献
998.
Comparison of high order aberration after conventional and customized ablation in myopic LASIK in different eyes of the same patient 总被引:4,自引:0,他引:4
Purpose: To verify whether there exists any difference in higher order aberrations after undergoing myopic LASIK (laser in situ keratomileusis) with conventional ablation and customized ablation in different eyes of the same patient. Methods: This was a prospective randomized study of 54 myopic eyes (27 patients) that underwent LASIK using the Nidek EC-5000 ex-cimer laser system (Nidek, Gamagori, Japan). Topography-guided customized aspheric treatment zone (CATz) was used in the first eye of the patient (study group) and the other eye of the same patient was operated on with conventional ablation (control group). Higher order aberrations [root-mean-square (RMS) in the 5-mm zone] of both groups were observed with the Nidek OPD-Scan aberrometer before and 3 months after LASIK. Preoperative mean refractive error was similar between two eyes of the same patient (t=?0.577, P>0.05). Results: Preoperatively, higher order aberrations (RMS in the 5-mm zone) in the CATz ablation and conventional groups were (0.3600±0.0341) μm and (0.2680±0.1421) μm, respectively. This difference was not statistically significant (t=1.292, P>0.05). Three months after LASIK, higher order aberrations (RMS in 5-mm zone) in the CATz ablation and conventional groups were (0.3627±0.1510) μm and (0.3991±0.1582) μm, respectively. No statistically significant difference was noted between pre- and postoperative higher order aberrations in the CATz group (t=?0.047, P>0.05). However, a statistically significant increase in higher order aberrations was observed after conventional ablation (t=?5.261, P<0.05). A statistically sig-nificant difference was noted in the increase of higher order aberrations after LASIK between groups (t=?2.050, P=0.045). Con-clusion: LASIK with conventional ablation and topography-guided CATz ablation resulted in the same BSCVA (best specta-cle-corrected visual acuity) 3 month after LASIK. Higher order aberrations were increased, but the increase of higher order ab-errations after customized ablation treatment was less than that after conventional ablation. 相似文献
999.
Learners’ ability in dealing with socio-scientific issues has been highlighted in contemporary science education. This study explored the effects of different on-line searching activities on high school students’ cognitive structure outcomes and informal reasoning outcomes. By using a quasi-experimental research approach, thirty-three students were assigned to a “guided searching task group”, while thirty-five students were assigned to an “unguided searching task group”. The treatments of this study were two different on-line searching activities. All the participants were asked to search relevant information regarding nuclear power usage on the Internet during the period of two classes (100 min). However, the students in the un-guided searching task group were asked to search freely, while those in the guided searching task group were provided with a searching guideline. The participants’ cognitive structures outcomes as well as their informal reasoning outcomes regarding nuclear power usage were assessed before and after the conduct of on-line searching tasks. The results of ANCOVA revealed that the students in the guided on-line searching task group significantly outperformed their counterparts in the extent (p < 0.01) and the richness of their cognitive structures (p < 0.01). Also, they significantly outperformed their counterparts in the usage of the two information processing strategies, “comparing” (p < 0.05) and “inferring or explaining” (p < 0.05). Moreover, it was also found that the students in the guided on-line searching task group only outperformed their counterparts in their supportive argument construction (p < 0.05). In other words, the guided searching tasks did help the students obtain better cognitive structure outcomes; however, the increments on their cognitive structure outcomes may only help them to propose more supportive arguments, but their rebuttal construction (an important indicator for their reasoning quality) was not particularly improved. 相似文献
1000.
Gerard A. Postiglione 《Higher Education》2011,62(6):789-814
This paper presents a perspective on the capacity of colleges and universities during past and present economic shocks. The
main argument is that the environment of the global recession—an Asia far more economically integrated than during past economic
shocks, with more unified aspirations to be globally competitive and socially responsible—no longer delay reforms in higher
education. In fact, the global recession has become an opportune time for higher education in Asia, specifically developing
countries in eastern (East and Southeast) Asia, to continue reforming governance and administration, access and equity, internal
and external efficiency, and regional collaboration. Economic shocks have accelerated reforms in higher education, especially
those for promoting innovation in their economies, though more is needed in improving governance and access for underserved
populations. This paper examines the cases of China, Mongolia, and Vietnam as examples of how the global recession and regional
integration are growing forces in shaping their higher education reform and development. The paper also identifies a series
of measures for increasing the resilience of higher education systems in serving poor and vulnerable populations during economic
recessions. Responses to the global economic recession by nations in eastern Asia are likely to improve the global shift in
economy and human capital. 相似文献