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Search Results: 1 - 10 of 127069 matches for " LI Xiangli "
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The Discrimination Classification in the Listed Companies in Accordance with the Market Quality Indexes
Xiangli LI,Shaorong SUN
Management Science and Engineering , 2010,
Abstract: All listed companies in the Shanghai Stock Exchange in 2008 were ranked according to the total market capitalization, the revenue and the net profit. The top 100 listed companies and the countdown listed companies were selected. Then the random 100 listed companies were extracted. The two discrimination classification functions of the listed companies in accordance with the market quality indexes were established by the three types companies as categorical dependent variables and the price impacting index, the liquidity index, the large transaction costs and the excess volatility ratio as the independent variables that were selected among the 11 market quality indexes by the forward stepwise method. The accuracy rate of the discrimination classification functions of the listed companies was 77.74% through verifying by the original back substitution. The classification results were significant. Key words: The price impacting index; The liquidity index; The large transaction costs; The excess volatility ratio; The discrimination classification function
The Research of Three-phase Boost/Buck-boost DC-AC Inverter  [PDF]
Xiangli Li, Zhaoyang Yan, Yanni Gao, Hanhong Qi
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.54B174

This paper presents a new inverter based on three-phase Boost/Buck-boost single-stage inverter. The basic configuration of the new topology and their fundamental principle are firstly introduced, the method of design double-loop controller and sliding mode controller are clarified, analyzed and compared in the following. Finally the validity and feasibility of the new topology are tested by simulation. The results indicate that regulation of the voltage transfer ratio and output frequency can be realized optionally by the new converter, furthermore the harmonic distortion of waveform is low. So the inherent drawback of low voltage transfer ratio of traditional converter is effectively settled. This study may provide inspiration for further engineering application.

The Control Technology Research of the Z-source Three-phase Four-bridge Arm Inverter  [PDF]
Xiangli Li, Zhaoyang Yan, Keke Pan, Chenghao Ma, Hanhong Qi
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.54B142

Z-source inverter can boost the voltage of the DC-side, allow the two switches of the same bridge arm conducting at the same time and it has some other advantages. The zero-sequence current flows through the fourth leg of the three-phase four-leg inverter so the three-phase four-leg inverter can work with unbalanced load. This paper presents a Z-source three-phase four-leg inverter which combines a Z-source network with three-phase four-leg inverter. The circuit uses simple SPWM modulation technique and the fourth bridge arm uses fully compensated control method. The inverter can maintain a symmetrical output voltage when the proposed scheme under the unbalanced load.

The Current and Future of Software Securities and Vulnerabilities  [PDF]
Cuixue Zhang, Meijiao Zhou, Yalian Xie, Xiangli Li
Journal of Software Engineering and Applications (JSEA) , 2014, DOI: 10.4236/jsea.2014.71001

As it has been stepping into the e-time period, software, which is considered as the key factor of the network and computer development, has become an integral part of everyday life. Millions of people may perform transaction through internet, mobile phone, ATM, and send e-mails, handle word processing or spreadsheets for different purposes. In another word, the network and information have been related to our daily life completely. Then, by IT advancing, the awareness of software security becomes a hot and serious topic. This paper will give some comments in various aspects, such as, in the beginning of the SDLC (System Development Life Cycle), how do designers analyze the functional and non-functional requirements and choose the proper development model? And then the testing professors take which kinds of methods to test the software with white-box testing or black-box testing to discover the vulnerabilities and flaws. At the same time, the paper gives some examples to demonstrate why the security of software is pretty important and what we should do to secure that. In addition, the paper will talk something about the enterprises’ actions to build a more secure network environment.

Understanding Children’s Physical Activity and Health-Related Quality of Life: An Expectancy-Value Approach  [PDF]
Xiangli Gu
Advances in Physical Education (APE) , 2017, DOI: 10.4236/ape.2017.72013
Abstract: This review paper explores the motivational processes in physical education related to physical activity and health-related quality of life among children and adolescents. First, we review the existing body of literature relating to children’s health-related quality of life. Next, we present the expectancy-value model of achievement choice as a framework for investigating how children’s motivation in physical activity settings interacts with physical activity and health-related quality of life. In the following section, we discuss social-contextual factors within the motivational climate, and how they can enhance or constrain decisions to be physically active and influence health-related quality of life. We conclude by identifying emerging research issues, implications for practice, and suggestions for future research directions.
Changes of Children’s Motivation in Physical Education and Physical Activity: A Longitudinal Perspective  [PDF]
Xiangli Gu, Tao Zhang
Advances in Physical Education (APE) , 2016, DOI: 10.4236/ape.2016.63022
Abstract: Children’s motivation towards Physical Education (PE) decreases over the elementary school year, but little is known about how and why those declines influence changes of children’s intention and Physical Activity (PA). Guided by the expectancy-value model, this study attempted to examine the relationship between changes of children’s motivation to changes in children’s intention for future participation in PE and PA over an academic year. Using a repeated measurement technique, 354 (4th 180, 5th 174) school children’s expectancy-related beliefs, task values, intention, and PA were assessed twice over one academic school year. Time 1 was at the beginning of the fall semester, and Time 2 was at the end of the subsequent spring semester. Students’ expectancy-related beliefs and task values were positively related to their intention and PA at both Time 1 and Time 2. A factorial repeated measure MANOVA showed that decreases in task values and intention were significant (p < .01). Regression analyses indicated that decreases in children’s expectancy-related beliefs and task values explained significant variance in a decrease in their intention. Additionally, changes of expectancy-related beliefs emerged as significant predictors of changes in children’s PA. The findings revealed that children perceived less values toward PE across one academic year. Consequently, this change could contribute to the decreases in children’s intention for future participation. Thus, PE teachers should focus on learning activities students perceive as important, interesting, and usefulness in elementary school.

A Performance Value Adaptive Routing for Mobile Ad Hoc Network
Xiangli Li,Kaimin Wei,Xiaolin Sun,Yanhong Gao
Journal of Networks , 2011, DOI: 10.4304/jnw.6.9.1367-1372
Abstract: The traditional route selection algorithm of the Ad Hoc network are mainly based on the shortest path and do not take into account any other routing factors. As a result, it increases the number of the unreliable route. It also forms a lot of “hot spot”, which affect the performance of the network. Thus this paper proposes a performance value adaptive routing for mobile ad hoc network (PVAR), which is mainly based on the performance value of the route. The PVAR uses a cross-layer design method that involves the medium access control layer and the network layer, and introduces a new route selection algorithm. Simulation results show that the PVAR can perform much better than the DSR in route reliability improving, congestion controlling and load balancing.
A Study on the Innovation of Teaching Management in Southwest Petroleum University  [PDF]
Xiangli Meng
Creative Education (CE) , 2019, DOI: 10.4236/ce.2019.106079
Abstract: The level of teaching management in colleges and universities affects the quality of teaching management in colleges and universities, teaching quality in colleges and universities, and further affects the quality of personnel training in colleges and universities. At present, Southwest Petroleum University is strengthening the management of teaching and improving its management level. There are many factors affecting the teaching management level and quality of Southwest Petroleum University. As one of the main carriers of teaching management of Southwest Petroleum University, students have important theoretical and practical significance in improving the management level by evaluating the teaching management satisfaction and finding out the existing problems and solutions. This study first summarizes the problems existing in the daily teaching management, teaching guarantee management and teaching quality management of Southwest Petroleum University. Secondly, it analyses the causes of the problems. Finally, it puts forward the corresponding solutions to the problems and causes.
Co-Deletion of Chromosome 1p/19q and IDH1/2 Mutation in Glioma Subsets of Brain Tumors in Chinese Patients
Xiaohui Ren, Xiangli Cui, Song Lin, Junmei Wang, Zhongli Jiang, Dali Sui, Jing Li, Zhongcheng Wang
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0032764
Abstract: Objective To characterize co-deletion of chromosome 1p/19q and IDH1/2 mutation in Chinese brain tumor patients and to assess their associations with clinical features. Methods In a series of 528 patients with gliomas, pathological and radiological materials were reviewed. Pathological constituents of tumor subsets, incidences of 1p/19q co-deletion and IDH1/2 mutation in gliomas by regions and sides in the brain were analyzed. Results Overall, 1p and 19q was detected in 339 patients by FISH method while the sequence of IDH1/2 was determined in 280 patients. Gliomas of frontal, temporal and insular origin had significantly different pathological constituents of tumor subsets (P<0.001). Gliomas of frontal origin had significantly higher incidence of 1p/19q co-deletion (50.4%) and IDH1/2 mutation (73.5%) than those of non-frontal origin (27.0% and 48.5%, respectively) (P<0.001), while gliomas of temporal origin had significantly lower incidence of 1p/19q co-deletion (23.9%) and IDH1/2 mutation (41.7%) than those of non-temporal origin (39.9% and 63.2%, respectively) (P = 0.013 and P = 0.003, respectively). Subgroup analysis confirmed these findings in oligoastrocytic and oligodendroglial tumors, respectively. Although the difference of 1p/19q co-deletion was not statistically significant in temporal oligodendroglial tumors, the trend was marginally significant (P = 0.082). However, gliomas from different sides of the brain did not show significant different pathological constituents, incidences of 1p/19q co-deletion or IDH1/2 mutation. Conclusion Preferential distribution of pathological subsets, 1p/19q co-deletion and IDH1/2 mutation were confirmed in some brain regions in Chinese glioma patients, implying their distinctive tumor genesis and predictive value for prognosis.
Journal of the Chilean Chemical Society , 2008, DOI: 10.4067/S0717-97072008000100020
Abstract: a rapid, simple and reliable method was devised for separation and determination of six metal cations, based on the capillary zone electrophoresis. the results showed that the complete separation of k+,cu2+, zn2+, mn2+, pb2+and cd2+canbe achieved within 5 min. anew electrolyte system containing 15 mmol-l"1 imidazole as a background absorbance reference and 8 mmol-l"1 malonic acid, 2 mmol-l-1 18-crown-6 ether as the complexing agents, 10%methanol as anorganic modifier, by using acetic acid to adjust the ph=4.40 was developed. the applied voltage was 20 kv at 25 °c. under the optimum conditions, 6 ions were separated and determined with the correlation coefficient of 0.9984-0.9993. the detection limits (s/n=3) from 0.05 (k+)to 0.75 (zn^mg-l1. the repeatability of migration times was less than 0.60% and of peak area ranged from 3.4 to 5.6% (n=6). the results were compared with aas for analyzing the real samples of waste-water and snow water
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