无线数据传输系统的设计与应用

介绍一种无线数据传输系统的设计与应用。该系统以nRF24101无线收发模块和STR89C52单片机为核心。通过软、硬件设计,充分发挥“跳频”、“学习”、“配对防锵”等先进技术,实现了无线数据信息传输的安全可靠,具有低成本、易扩展、操作简单等特点,可应用于远程无线数据传输。     

Participation in Canadian Universities: The gender imbalance (1977–2005)

Females are more likely to attend Canadian universities and their participation rate has been increasing faster than that of males, generating a 15 percentage point gap by 2005. We investigate the determinants of attending university and explore the reasons for the increasing gender gap. As in the US literature, we find that conventional decompositions, averaging over the whole sample, attribute most of the gender gap to differences in variables, notably the University Premium. The average sample approach in these decompositions abstracts from the evolution over time of the participation rates by gender and from important detail at specific points in time, features that we try to overcome. We find that the rising level of the university participation rate for both women and men can be explained by changing societal norms, the dynamic influence of parental education, the University Premium, tuition fees and real income. The 2005 gap between the female and male participation rates can be accounted mostly (9 percentage points) by the gender differences in the University Premium and, to a lesser extent (6 percentage points), by differences in the coefficients in the female and male participation equations.     

磷酸三钠对提高烟草种子活力及抑制TMV的效果

通过不同质量分数的磷酸三钠溶液震荡浸泡烟草种子30 m in,对种子的出苗和大田烟株TMV的发病情况进行调查统计.结果表明：1）30%和40%的磷酸三钠溶液对增强种子的活力有明显效果,播种后14 d出苗率分别达到63.5%和69.2%,分别比清水对照提高了13.9%和19.6%;2）30%和40%的磷酸三钠溶液处理种子30 m in,可使大田烟株对TMV有显著的抑制效果,与其它处理的差异显著水平达到0.01;3）大田期烟株TMV的病情变化趋势,几乎不受磷酸三钠溶液处理的影响,而主要与降雨等气候因素关系密切.     

大学生网球教学比赛前后心率和收缩压、舒张压变化特征的实验研究

为了解大学生网球教学比赛的负荷特征,探索HR(心率)和BSP(收缩压)、BDP(舒张压)在网球运动负荷监控研究中效用,通过实验观测了12名普通大学生在网球教学比赛中的HR和BSP、BDP变化情况,研究发现:大学生网球教学比赛后即刻平均心率HR为116.17±6.73bpm;赛中最大值心率HRmax只达到144bpm。HR可作为网球运动负荷监控的有效指标,而BSP、BDP的监控效用不明显。     

无线病房呼叫系统设计与实现

为解决传统有线病房呼叫系统布线复杂、维修不便且明线不雅观等问题,设计了一种具有无线通信功能的病房呼叫系统。系统以单片机为核心,采用无线收发模块NRF2401和语音模块YY01,实现了病患与医务人员之间信息传输与反馈的功能,同时可将呼叫信息存储在监控计算机上,以便于信息管理。结果表明,系统配置灵活、功能可扩展、价格低廉,具有良好的可操作性。     

Towards cost efficient mobile service and information management in ubiquitous environment with cloud resource scheduling

The past few years have witnessed an explosive popularity of mobile services, especially in the form of smart phone applications. To cope with the limited batteries and computational capacities of mobile devices, prior studies suggest to deploy service instances in clouds for accomplishing most of the computation-intensive tasks. Service composition, which compensates for the simplicity of single service, is an effective way to utilize the plentiful services on the clouds all over the world. In this paper, we focus on the problem of service instance selection with service instance replica limitation constraint. The objective is to select the optimal set of service instances, which composes the integrated service and brings out the optimal QoS (quality of service), in terms of service response time. To characterize the problem, we establish a new QoS model, which considers the comprehensive quality over all users, not just for any single user or service instance. We prove that the problem is NP-hard, since many functionally equivalent service instances spread all over the distributed clouds. To address the problem, we classify the problem into three cases, including two special cases and the general case. We present two effective heuristic algorithms to determine the service instances selection for the two special cases, which are still NP-hard. The two special cases provide empirical bounds for the general case. We propose an algorithm that simulates a vote procedure for the users in the general case. The selected service instances, which come from the vote procedure, can satisfy a majority of users. We conduct extensive simulations for all of the algorithms. The simulation results show that our algorithms work efficiently on service response time reduction.     

HClaimE: A tool for identifying health claims in health news headlines

This study tackles the problem of extracting health claims from health research news headlines, in order to carry out veracity check. A health claim can be formally defined as a triplet consisting of an independent variable (IV – namely, what is being manipulated), a dependent variable (DV – namely, what is being measured), and the relation between the two. In this study, we develop HClaimE, an information extraction tool for identifying health claims in news headlines. Unlike the existing open information extraction (OpenIE) systems that rely on verbs as relation indicators, HClaimE focuses on finding relations between nouns, and draws on the linguistic characteristics of news headlines. HClaimE uses a Naïve Bayes classifier that combines syntactic and lexical features for identifying IV and DV nouns, and recognizes relations between IV and DV through a rule-based method. We conducted an evaluation on a set of health news headlines from ScienceDaily.com, and the results show that HClaimE outperforms current OpenIE systems: the F-measures for identifying headlines without health claims is 0.60 and that for extracting IV-relation-DV is 0.69. Our study shows that nouns can provide more clues than verbs for identifying health claims in news headlines. Furthermore, it also shows that dependency relations and bag-of-words can distinguish IV-DV noun pairs from other noun pairs. In practice, HClaimE can be used as a helpful tool to identifying health claims in news headlines, which can then be further compared against authoritative health claims for veracity. Given the linguistic similarity between health claims and other causal claims, e.g., impacts of pollution on the environment, HClaimE may also be applicable for extracting claims in other domains.     

多点信息采集系统的分析与设计——通讯及控制硬件电路设计

加强公司职员的心理健康教育,是新时期促进其全面和健康成长的迫切需要。及时、准确、全面地了解公司职员心理状况是进行心理健康教育的基础。为了提高心理测试水平,设计了心理测试系统。设计中硬件采用了Freescale公司的8位单片机MC9S08GT60作为MCU,Nordic公司的nRF24L01作为射频芯片,RS-232串口作为与上位机通信的接口完成无线通信模块,并使用C语言完成软件设计。实验结果表明:使用无线数据传输技术对团测可以起到积极的作用,具有一定的实际意义。     

Retraction statements and research malpractice in economics

We draw on rational crime theory to help analyse 55 articles that have been retracted from 734 peer-reviewed journals in the field of economics. We highlight and discuss what these findings indicate regarding the nature and pattern of research malpractice in that discipline. Particular attention is given to exploring “no reason” retractions and the policy guidelines of publishers regarding retracted papers. We conclude that the frequent vagueness of retraction statements, and a reluctance to signal research malpractice, generally results in little damage to the reputation of caught, and known, offenders. Thus, a key deterrent to engaging in research malpractice is lacking. To reduce the incidence of research malpractice, we offer several recommendations for publishers and journal editors.     

基于ADS的低噪声放大器的仿真设计

利用NE3210S01芯片对低噪声放大器进行设计,先介绍低噪声放大器的相关指标,对普通低噪声放大器进行改造,通过ADS软件对低噪声放大器进行仿真,然后对改造后的放大器的稳定性、噪声系数进行分析.