OALib Journal期刊

ISSN: 2333-9721




2019 ( 14 )

2018 ( 111 )

2017 ( 98 )

2016 ( 89 )


匹配条件: “Zhao” ,找到相关结果约34838条。
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.
Nonalgorithmicity and algorithmicity of protein science  [PDF]
Qinyi Zhao
Advances in Bioscience and Biotechnology (ABB) , 2011, DOI: 10.4236/abb.2011.25050
Abstract: The metaphysical features of the mechanism for the integration of the information underlying protein folding were studied by applying principles of system logic theory. We conclude that it is not possible to predict all protein three-dimensional structures from protein sequences by one program only. This conclusion is validated in structural genomics in that we also cannot predict protein function from three-dimensional structure by one program only. Our theory also demonstrates that bioinformation flow from gene to biological function is an integration process, rather than an expression (translation) process. A system relationship between a gene and its biological function is also proposed. This electronic document is a “live” template.
Monopoly and Economic Efficiency: Perspective from an Efficiency Wage Model  [PDF]
Bo Zhao
Modern Economy (ME) , 2011, DOI: 10.4236/me.2011.25092
Abstract: The objective of this paper is to analyze the efficiency consequences of monopoly from the perspective of an efficiency-wage model based on Shapiro and Stiglitz (1984). An important innovation of our model is that a firm can raise the probability that a shirking worker is detected by increasing its effort or investment in the monitoring of workers. By comparing with the competitive equilibrium we find that monopoly is associated with higher unemployment rate and less monitoring. Surprisingly, however, monopoly is not necessarily dominated by perfect competition in terms of economic efficiency.
In Search of the Effects of Competition on Unemployment: Evidence from OECD Countries  [PDF]
Bo Zhao
Journal of Service Science and Management (JSSM) , 2011, DOI: 10.4236/jssm.2011.44051
Abstract: This paper explores the empirical relationship between unemployment rate and product market competition in eighteen OECD countries through three sets of quantitative analyses. We find that the effect of competition on employment depends on the existing competition intensity and the relationship between the unemployment and competition appears to be inverted-N shape—in countries where existing competition intensity is either high or low, an increase in competition tends to reduce unemployment rate significantly; but for countries where existing competition intensity is moderate, intensified competition is more likely to increase unemployment rate significantly.
Research on Synthetical Production Proration of Deep Gas Well in Xu Jiaweizi Block Considering Multi Influential Factors  [PDF]
Qingbo Zhao
Smart Grid and Renewable Energy (SGRE) , 2012, DOI: 10.4236/sgre.2012.32021
Abstract: Xu deep volcanic gas reservoir is typical of complex lithology, severe inhomogeneity, big difficulty to extract. Pressure sensitivity always exists in gas reservoirs. Prorating production is too high or low, causing problems, as for the energy loss, reservoir damage, bottom effusion, thus lowing the gas productivity and affecting development benefit. So it have to research on a new reasonably production proration method considering multi influential factors. It is a reasonably production proration method considering multi influential factors in Xu gas reservoir, with guidelines such as capacity use, pressure draw down, gas recovery rate, water out and throughout water data is reasonably, so we can long term use it to guide gas field exploitation.
N-Fold Darboux Transformation for a Nonlinear Evolution Equation  [PDF]
Yannan Zhao
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.38141
Abstract: In this paper, we present a N-fold Darboux transformation (DT) for a nonlinear evolution equation. Comparing with other types of DTs, we give the relationship between new solutions and the trivial solution. The DT presented in this paper is more direct and universal to obtain explicit solutions.
Imputed Empirical Likelihood for Varying Coefficient Models with Missing Covariates  [PDF]
Peixin Zhao
Open Journal of Applied Sciences (OJAppS) , 2013, DOI: 10.4236/ojapps.2013.31B1009

The empirical likelihood-based inference for varying coefficient models with missing covariates is investigated. An imputed empirical likelihood ratio function for the coefficient functions is proposed, and it is shown that iis limiting distribution is standard chi-squared. Then the corresponding confidence intervals for the regression coefficients are constructed. Some simulations show that the proposed procedure can attenuate the effect of the missing data, and performs well for the finite sample.

Study on Sport Injuries among College Students in Wuhan  [PDF]
Ying Zhao
Advances in Physical Education (APE) , 2013, DOI: 10.4236/ape.2013.32015

Objective: To investigate the characteristics and the precaution of and reduction of sport injuries among college students in Wuhan, and to provide evidence for the prevention. Methods: Stratified and cluster random sampling method was used to choose 1103 students from a university in Wuhan. A self-designed questionnaire was used to investigate the characteristics of sport injuries among172 college students who had experienced sport injuries. Results: The incidence of sport injuries among college students in Wuhan was 15.59%. Sport injuries were closely related with sports events, sports technique, physical condition of exerciser, and ground equipment. The incidence of sport injuries was higher in basketball, soccer and physical fitness exercise. Sport injuries were mainly soft tissue damage. The locations of injuries were primary in ankle joint (56.69%). Injuries induced by basketball & soccer were prone to occur in physical education class, while injuries caused by physical fitness exercise were prone to occur in extracurricular activities. Conclusion: The incidence of sport injuries was higher in basketball & soccer, and sport injuries were prone to occur in physical education class. It was imperative to strengthen the measures of prevention and intervention in college sport injuries.

The Relationship between Share Price Gains, Corporate Performance and Risk  [PDF]
Yujuan Zhao
iBusiness (IB) , 2013, DOI: 10.4236/ib.2013.53B023

In this paper, we have tested the relationship between the stock returns, corporate performance and investment risks with the sample of listed companies in the agricultural, construction and financial industries in the A-share stock market. Descriptive statistical analysis, correlation test and regression analysis indicate that there is no relationship between stock returns and corporate performance, but there exists a positive correlation between the stock returns and investment risks in the construction and financial industries.

To Update Ideas, to Explore New Model of Financial Managemen  [PDF]
Pengfei Zhao
iBusiness (IB) , 2013, DOI: 10.4236/ib.2013.53B040

With the reform and opening up of china, and the globalization of economy, Chinese enterprises are facing more and more complex financial environment, especially since 2008 financial crisis, the government's macro-control, the relative appreciation of RMB, rising labor costs and other non-financial constraints factors, have greatly changed the financial management content, objectives, theory, methods, and ways of working etc, enterprises financial management are suffering from a huge challenge. This paper analyzes the main problems of Chinese enterprises in financial management, and gives some suggestions to work out these problems.


Copyright © 2008-2017 Open Access Library. All rights reserved.