首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6篇
  免费   0篇
教育   4篇
科学研究   2篇
  2021年   1篇
  2013年   1篇
  2011年   1篇
  2010年   1篇
  2008年   1篇
  2007年   1篇
排序方式: 共有6条查询结果,搜索用时 0 毫秒
1
1.
In this paper, more efficient, low-complexity and reliable region of interest (ROI) image codec for compressing smooth low texture remote sensing images is proposed. We explore the efficiency of the modified ROI codec with respect to the selected set of convenient wavelet filters, which is a novel method. Such ROI coding experiment analysis representing low bit rate lossy to high quality lossless reconstruction with timing analysis is useful for improving remote sensing ground truth sur- veillance efficiency in terms of time and quality. The subjective [i.e. fair, five observer (HVS) evaluations using enhanced 3D picture view Hyper memory display technology] and the objective results revealed that for faster ground truth ROI coding applications, the Symlet-4 adaptation performs better than Biorthogonal 4.4 and Biorthogonal 6.8. However, the discrete Meyer wavelet adaptation is the best solution for delayed ROI image reconstructions.  相似文献   
2.
P. Ajith  K. G. Arun 《Resonance》2011,16(10):922-932
We present a broad overview of the emerging field of gravitational-wave astronomy. Although gravitational waves have not been directly detected yet, the worldwide scientific community is engaged in an exciting search for these elusive waves. Once detected, they will open up a new observational window to the Universe.  相似文献   
3.

Open Educational Resources (OER) integrated online courses provide a rich and a flexible learning environment to acquire knowledge and skills among undergraduates. A significant issue with OER-integrated online courses is the poorly addressed instructional design features. Instructionally rich online courses will have a greater impact on both teaching and learning. This study is aimed at exploring different support systems in relation to the undergraduate learning process through the design of OER-integrated online courses. It explored design features under four main Instructional Design (ID) aspects, being: Information Design, Instruction Design, Interface Design and Interaction Design. The study adopted a Design-Based Research approach through analysis, design, development, implementation and evaluation of an intervention in multiple phases, using mixed methodologies. This resulted in a design framework with reusable design principles for OER-integrated online learning. The outcomes of this study will contribute to enhance OER-integrated course design and to develop undergraduate education.

  相似文献   
4.
Chemoprevention represents a new intervention strategy to control some type of carcinogenesis especially in subjects at high risk for cancer development. Experimental and epidemiological data indicate that a variety of nutritional factors including vitamin C and E are effective to lower the risk of some types of cancer. However large prospective studies have failed to find such significant association. A comparative and combined in vitro antimutagenic potential of two antioxidant vitamins ascorbic acid (vitamin C) and α-tocopherol (vitamin E) were evaluated using Ame’s Salmonella typhimurium test assay. Directly acting mutagens such as sodium azide (NaN3) and 4-Nitro-o-phenylenediamine (NPDA), and N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) were used to induce mutation in salmonella strains TA 98 and TA 100. Vitamin C significantly (P < 0.01) and dose dependently inhibited the mutagenicity induced by all the three mutagens. The percent inhibitions of vitamin C at 15 mg/plate were 33.8% (NaN3), 52.5 % (MNNG) and 55.4 % (NPDA). Vitamin E (15 mg/plate) was effective to inhibit mutagenicity induced by NaN3 and MNNG but did not inhibit mutation induced by NPDA. Combination of vitamins (vitamin C plus vitamin E) produced only an additive antimutagenic activity when compared to their activity at 5 mg/plate. The results of the study concluded that vitamin C is a better antimutagenic agent than vitamin E and combination of vitamins did not produce any synergistic activity.  相似文献   
5.
Comparing the fit of alternative models has become a standard procedure for analyzing covariance structure analysis. Comparison of alternative models is typically accomplished by examining the fit of each model to sample data. It is argued that rather than using this indirect approach, one should do direct comparisons of the similarities and differences among competing models. It is shown that among the existing good‐ness‐of‐fit indexes, the root mean square residual (RMSR) is the only one that can be used for this purpose. However, the RMSR fails to satisfy some important statistical desiderata. Rao's Distance (RD), an alternate measure, is shown to overcome this limitation of RMSR. The preference for RD over RMSR for model comparisons is illustrated through a detailed analysis of a particular sample of multitrait‐multimethod data. A simulation study conducted to empirically investigate the sampling behavior of RD reveals that the true orderings of intermodel proximities are recovered (on average) with a fair degree of accuracy.  相似文献   
6.
Iron is an essential nutrient for a number of cellular activities. However, excess cellular iron can be toxic by producing reactive oxygen species (ROS) such as superoxide anion (O2) and hydroxyl radical (HO·) that damage proteins, lipids and DNA. Mutagenic and genotoxic end products of lipid peroxidation can induce the decline of mitochondrial respiration and are associated with various human ailments including aging, neurodegenerative disorders, cancer etc. Zingiber officinale Roscoe (ginger) is a widely used spice around the world. The protective effect of aqueous ethanol extract of Z. officinale against ROS-induced in vitro lipid peroxidation and DNA damage was evaluated in this study. The lipid peroxidation was induced by hydroxyl radical generated from Fenton’s reaction in rat liver and brain homogenates and mitochondrial fraction (isolated from rat liver). The DNA protection was evaluated using H2O2-induced changes in pBR-322 plasmid and Fenton reaction-induced DNA fragmentation in rat liver. The results indicated that Z. officinale significantly (P<0.001) protected the lipid peroxidation in all the tissue homogenate/mitochondria. The extract at 2 and 0.5 mg/ml could protect 92 % of the lipid peroxidation in brain homogenate and liver mitochondria respectively. The percent inhibition of lipid peroxidation at 1mg/ml of Z. officinale in the liver homogenate was 94 %. However, the extract could partially alleviate the DNA damage. The protective mechanism can be correlated to the radical scavenging property of Z. officinale. The results of the study suggest the possible nutraceutical role of Z. officinale against the oxidative stress induced human ailments.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号