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排序方式: 共有526条查询结果,搜索用时 31 毫秒
501.
TURAL DINCER Gvner AKDENIZ Ali Rlza 《美中教育评论》2008,5(12):54-59
There are many factors influence the level of students' achievement in education. Studies show that one of these factors is "learning approach of a student". Research findings generally have identified two approaches of learning: deep and surface. When a student uses the deep approach, he/she has an intrinsic interest in subject matter and is interested in ideas and conclusions to understand the subject matter. When a student employs the surface approach, he/she merely memorizes knowledge to pass any exam in school. The aim of this study is to determine learning approaches of science student teachers and to examine the relationships among the variables, such as level of students' class and gender. The sample of this study consists of 108 student teachers from the Science Education Program at Department of Primary Science Education in Karadeniz Technical University. Approaches to learning of science student teachers are assessed using the Revised Two-factor Study Process Questionnaire (R-SPQ-2F), a scale developed by Biggs, et al (2001) consisting of 20 items on a 5 point Likert Scale. According to findings, science student teachers generally have deep learning approaches. Moreover, learning approaches of science student teachers have not changed related to gender. 相似文献
502.
河北医药制造企业实施联合采购,能有效降低企业采购成本、提升利润空间。就联合采购实施的优势、模式以及需要解决等问题进行探讨。 相似文献
503.
Seyed Javad Mirabedini Mohammad Teshnehlab M. H. Shenasa Ali Movaghar Amir Masoud Rahmani 《浙江大学学报(A卷英文版)》2008,9(12):1666-1675
We propose a novel approach called adaptive fuzzy ant-based routing (AFAR), where a group of intelligent agents (or ants) builds paths between a pair of nodes, exploring the network concurrently and exchanging obtained information to update the routing tables. Routing decisions can be made by the fuzzy logic technique based on local information about the current network state and the knowledge constructed by a previous set of behaviors of other agents. The fuzzy logic technique allows multiple constraints such as path delay and path utilization to be considered in a simple and intuitive way. Simulation tests show that AFAR outperforms OSPF, AntNet and ASR, three of the currently most important state-of-the-art algorithms, in terms of end-to-end delay, packet delivery, and packet drop ratio. AFAR is a promising alternative for routing of data in next generation networks. 相似文献
504.
Collaborative filtering (CF) is a popular method for personalizing product recommendations for e-commerce applications. In order to recommend a product to a user and predict that user’s preference, CF utilizes product evaluation ratings of like-minded users. The process of finding like-minded users forms a social network among all users and each link between two users represents an implicit connection between them. Users having more connections with others are the most influential users. Attacking recommender systems is a new issue for these systems. Here, an attacker tries to manipulate a recommender system in order to change the recommendation output according to her wish. If an attacker succeeds, her profile is used over and over again by the recommender system, making her an influential user. In this study, we applied the established attack detection methods to the influential users, instead of the whole user set, to improve their attack detection performance. Experiments were conducted using the same settings previously used to test the established methods. The results showed that the proposed influence-based method had better detection performance and improved the stability of a recommender system for most attack scenarios. It performed considerably better than established detection methods for attacks that inserted low numbers of attack profiles (20–25 %). 相似文献
505.
Ramesh Ramji Ming Wang Ali Asgar S. Bhagat Daniel Tan Shao Weng Nitish V. Thakor Chwee Teck Lim Chia-Hung Chen 《Biomicrofluidics》2014,8(3)
Droplet-based microfluidics has shown potential in high throughput single cell assays by encapsulating individual cells in water-in-oil emulsions. Ordering cells in a micro-channel is necessary to encapsulate individual cells into droplets further enhancing the assay efficiency. This is typically limited due to the difficulty of preparing high-density cell solutions and maintaining them without cell aggregation in long channels (>5 cm). In this study, we developed a short pinched flow channel (5 mm) to separate cell aggregates and to form a uniform cell distribution in a droplet-generating platform that encapsulated single cells with >55% encapsulation efficiency beating Poisson encapsulation statistics. Using this platform and commercially available Sox substrates (8-hydroxy-5-(N,N-dimethylsulfonamido)-2-methylquinoline), we have demonstrated a high throughput dynamic single cell signaling assay to measure the activity of receptor tyrosine kinases (RTKs) in lung cancer cells triggered by cell surface ligand binding. The phosphorylation of the substrates resulted in fluorescent emission, showing a sigmoidal increase over a 12 h period. The result exhibited a heterogeneous signaling rate in individual cells and showed various levels of drug resistance when treated with the tyrosine kinase inhibitor, gefitinib. 相似文献
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Mst. Marium Begum Zakia Sultana Md. Ershad Ali Md. Safkath Ibne Jami Proma Khondkar Md. Masuduzzaman Khan Md. Mominul Haque 《Indian journal of clinical biochemistry : IJCB》2014,29(4):452-461
High blood glucose level, elevated level of liver enzyme, necrosis and shrinkage of islets of Langerhans has been implicated in the pathogenesis of type 2 diabetes. High blood glucose cause oxidative stress, production of free radical as well as elevated SGPT and SGOT level. Both glibenclamide and simvastatin in fixed dose used as antihyperglycemic antidyslipidemic and antioxidative agents for type 2 diabetes treatment. This study therefore aimed to evaluate the antihyperglycemic, antidyslipidemic and antioxidative effect of fixed dose combination of glibenclamide (0.6 mg/70 kg body weight) and simvastatin (5 mg/70 kg body weight) on long term alloxan induced diabetic rats with cardiovascular disease using various diagnostic kits as a parameter of phamacotherapeutic and pharmacological effect. The study was carried out using 96 Swiss Albino male rats weighing about 200–220 g. Combination therapy induced a significant decrease in blood glucose level in alloxan induced diabetic rats, from 33.75 ± 1.65 to 5.80 ± 0.07 mmol/l 2 h after last dose administration, after 4 weeks treatment. In case of dyslipidemic effect, combination therapy reduced total cholesterol (45 %), triglyceride (36 %) and low density lipoprotein-cholesterol (32 %) levels significantly and increased high density lipoprotein-cholesterol level (57 %) in comparison with their respective diabetic control groups. Results of this study showed that combination therapy effectively decreased SGPT (ALAT) (55 %) and SGOT (ASAT) (51 %) in comparison with diabetic control group. It was also observed that catalase and superoxide dismutase enzyme activity was increased by 58 and 91 % respectively in comparison with diabetic control group after 4 weeks treatment with combination of both drugs. In conclusion, these findings of combination therapy (glibenclamide and simvastatin) on alloxan induced diabetes in rats are significantly better than monotherapy using single drug. The results of the present study suggest that, combination of the fixed dose of glibenclamide and simvastatin might be efficacious in patients with diabetic dyslipidemia and increased oxidative stress. Furthermore, this combination therapy offer dosage convenience to the patients and by virtue of its dual mode of action might be a useful addition to the therapeutic armamentarium for patients with diabetic dyslipidemia and oxidative stress. 相似文献
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510.
Zhenwei Liu Ali Saberi Anton A. Stoorvogel Donya Nojavanzadeh 《Journal of The Franklin Institute》2021,358(9):4864-4882
In this paper, we design scale-free collaborative protocols for state and regulated state synchronization of homogeneous multi-agent systems (MAS) with arbitrary fast convergence. The protocol design solely depends on the knowledge of the agents’ model and does not require any information about the communication network and the number of agents. Moreover, our protocols can achieve synchronization with any desired convergence rate by simply tuning a design parameter. 相似文献