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Search Results: 1 - 10 of 90822 matches for " Yang Zhao "
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Estimating the Size of an Injecting Drug User Population  [PDF]
Yang Zhao
World Journal of AIDS (WJA) , 2011, DOI: 10.4236/wja.2011.13013
Abstract: This article describes a sampling and estimation scheme for estimating the size of an injecting drug user (IDU) population by combining classical sampling and respondent-driven sampling procedures. It is designed to use the information from harm reduction programs, especially, Needle Exchange Programs (NEPs). The approach involves using respondent-driven sampling design to collect a sample of injecting drug users who appear at site of NEP in a certain period of time and to obtain retrospective self-report data on the number of friends among the IDUs and number of needles exchanged for each sampled injecting drug user. A methodology is developed to estimate the size of injecting drug users who have ever used the NEP during the fixed period of time, and which allows us to estimate the proportion of injecting drug users in using NEP. The size of the IDU population is estimated by dividing the total number of IDUs who using NEPs during the period of time by the estimated proportion of IDUs in the group. The technique holds promise for providing data needed to answer questions such as “What is the size of an IDU population in a city?” and “Is that size changing?” and better understand the dynamics of the IDU population. The methodology described here can also be used to estimate size of other hard-to-reach population by using information from harm reduction programs.
Simulation and Experimental Study on the Atomization Character of the Pressure-Swirl Nozzle  [PDF]
Jianbo Zhao, Lijun Yang
Open Journal of Fluid Dynamics (OJFD) , 2012, DOI: 10.4236/ojfd.2012.24A032
Abstract: In this paper the atomization character of the pressure-swirl injector was measured by using the Phase Doppler Particle Analyzer (PDPA) in the section of 150 mm below the outlet of the orifice. The orifice diameter of the pressure-swirl injector is 0.62 mm. The atomization character includes the spray angle, the water flow rate, the Sauter mean diameter (SMD), the velocity of the particles and their distribution in the radial and the axial directions under the pressure from 1 MPa to 4.5 MPa. After that the atomization character of the pressure-swirl injector was simulated in the DPM panel. The same atomization character of the injector was calculated and compared with the experimental data. The simulation was corrected by using the experimental data which can make it accurately and the model can be used to predict and calculate the atomization character of different injectors.
Research on Combined Hot Extrusion Forming Process of Alternator Poles  [PDF]
Cheng Yang, Shengdun Zhao
Journal of Materials Science and Chemical Engineering (MSCE) , 2013, DOI: 10.4236/msce.2013.15004
Abstract:

Based on the structure analysis of alternator poles, two closed die forging steps in one heat forming process of alternator poles were put forward, as well as the forming die system. Firstly, a thicker bottom base of alternator poles was per-formed by radial forging, then the middle boss and pole claw were forming on the bottom base by backward extrusion. A 3-D coupled thermo-mechanical finite element model was created. The billet deformation, metal flow and forming load were obtained. The results showed that a filling well forging without overlap defects could be obtained by this process, and that the forming load at the first step increased slowly, but the load increased sharply at the second step when the middle boss was filling completely by the former process. An improved process was put forward, which changed the flow mode in the second forging step, it can considerably reduce the final forging load.

A New Delay-Constrained Multicast Routing Algorithm Based on Shared Edges  [PDF]
Chunde Yang, Xin Zhao
Communications and Network (CN) , 2014, DOI: 10.4236/cn.2014.61006
Abstract:

In this paper, we made a detail analysis for the ESAMPH algorithm, and proposed ESAMPH_D algorithm according to the insufficient of ESAMPH algorithm. The ESAMPH_D algorithm does not consider those paths that do not satisfy the delay constraint, so we can ensure that all paths be taken into account will meet the limit of delay constraint, then we find the least costly path in order to build a minimum cost multicast tree. Simulation results show that the algorithm is better than ESAMPH algorithm in performance.

The Network Educational Resources Construction on Meteorology Based on Data Mining  [PDF]
Rui Chen, Yang Zhao
Open Journal of Social Sciences (JSS) , 2015, DOI: 10.4236/jss.2015.36001
Abstract:

With the vigorous development of the modern network education technology, the construction of network resource developed towards digital, intelligent and personalized, in order to satisfy the distance learners of different learning needs. By analyzing the problems currently learners in the use of the repository for learning generated by the proposed use of data mining techniques to further planning and construction of the repository, and on how to improve the organizational structure of the repository, and improve the utilization of the repository, personalized to meet the current in-depth research and analysis of learning problems.

Research on the Influence of Foreign Trade on Upgrading of Industrial Structure in Shaanxi Province —Empirical Analysis Based on New Silk Road Economic Belt  [PDF]
Haizhen Yang, Wenping Zhao
Open Journal of Business and Management (OJBM) , 2016, DOI: 10.4236/ojbm.2016.43057
Abstract: The construction of the “New Silk Road Economic Belt” will inevitably expand the development scale of foreign trade in economic belt relevant area. Based on the data from 1990 to 2013 in Shaanxi Province, this paper analyzes the economic correlation effects of foreign trade on the upgrading of industrial structure in Shaanxi province by using gray relation analysis method. Results show that the foreign trade is highly correlated with GDP and three industrial added values. Moreover, performance of foreign trade and upgrading of industrial structure of Shaanxi Province are also analyzed by using Co-integration and Granger test. It is found that foreign trade has the most promotion to the third industry, the second industry follows, and the first industry least. That is to say, foreign trade of Shaanxi Province is constantly promoting industrial structure shift from “Two ? Three ? One” model to the “Three ? Two ? One” model.
Research on Corrosion Protection of Buried Steel Pipeline  [PDF]
Xiaoxu Chen, Yang Zhao
Engineering (ENG) , 2017, DOI: 10.4236/eng.2017.95030
Abstract: The corrosion types of buried steel pipelines were summarized from two aspects of internal corrosion and external corrosion; the main detection technology for internal and external corrosion was introduced; and the protective measures for corrosion and corrosion of buried steel pipelines were presented. The study of corrosion protection for buried steel pipeline provided the basis for the corrosion protection of buried steel pipeline.
The Effect of Job Autonomy on Psychological Well-Being: The Mediating Role of Personal Initiative  [PDF]
Feifei Yang, Yue Zhao
Open Journal of Social Sciences (JSS) , 2018, DOI: 10.4236/jss.2018.611017
Abstract: Employees’ psychological well-being is an important factor affecting organizational performance. Thus, through empirical study, the present article investigates the influence of employees’ job autonomy on their psychological well-being. Specifically, personal initiative will mediate this relationship. To examine a series of hypotheses we developed, online survey was used to collect data. Finally, 380 respondents were accepted. Empirical data showed that employees’ job autonomy is positively related to psychological well-being. Namely, the psychological well-being of employees will gain dramatic improvement when they possess high job autonomy. In addition, through the way of path analysis, we revealed that personal initiative plays a role of intermediary mechanism in the relationship between job autonomy and psychological well-being. In last part, we discussed the contribution, limitations, and the directions of future research.
Joint Link Scheduling for Optimal Management of Radio Resources in Satellite Systems
Zhao Yang
International Journal on Computer Science and Engineering , 2011,
Abstract: This paper mainly focuses on the solving of joint link scheduling, which is a major aspect of resource allocation in a wireless satellite communication system. A brief review of some early definitiveschedulers are presented and evaluated first, then the prevailing heuristic scheduler, alongside with the most up-to-date intelligent optimal schedulers are further introduced. Some problems which still exist in current schedulers are brought forward and discussed at the end of this paper.
Effect of Neodymium on the Crystallization, Microstructure and Colorization of Li2O-Al2O3-SiO2 Glass Ceramics  [PDF]
Xingzhong Guo, Wenyan Li, Hui Yang, Jiajie Zhao, Wenda Zhao
New Journal of Glass and Ceramics (NJGC) , 2012, DOI: 10.4236/njgc.2012.22014
Abstract: The effect of single coloring agent Nd(NO3)3 on the crystallization, microstructure and colorization of Li2O-Al2O3-SiO2 (LAS) glass ceramics were investigated by differential thermal analysis (DTA), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The introduction of little neodymium has no effect on the crystallization manner and the formation of main crystallization phase, but more neodymium will weaken the crystallization of LAS glass. Little neodymium can increase the glossiness of LAS glass ceramic, while more neodymium can color LAS glass with light purple or red purple. The colorability of neodymium for LAS glass ceramic decreases with the increase of crystallization temperature.
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