基于Prophet-LSTM模型的PM2.5浓度预测研究

作为衡量空气质量的重要指标,准确预测PM2.5浓度变化尤为重要。提出Prophet和长短期记忆（LSTM）相结合的组合预测模型（Prophet-LSTM）。在模型构建过程中,首先利用Prophet模型的可分解方法,将PM2.5日值浓度序列分解成趋势、周期和随机波动分量|然后对趋势和周期分量建立Prophet模型,对随机波动分量建立LSTM模型|最后将各分量的预测值集成得到PM2.5浓度的预测值。以郑州市PM2.5日值浓度数据为例进行实证分析,结果表明,该组合预测模型相较对比模型能够更好地预测PM2.5日值浓度的变化趋势。     

灰色模型在PM2.5预测中的应用

PM2.5对空气质量和能见度等有重要的影响,了解其变化趋势,对制定合理的治理机制具有现实意义.在传统的GM(1,1)模型的基础上,提高数据的光滑度,建立了改进的GM(1,1)模型,并利用MATLAB实现GM(1,1)模型算法.以石家庄市PM2.5浓度作为研究对象,以历史数据预测未来数据,并检验其精度.结果显示,石家庄市PM2.5浓度,在短期内仍将保持较高值,采取措施控制PM2.5浓度不容忽视.     

金华居民环保意识对PM2.5污染影响研究

随着中国空气质量的不断恶化,PM2.5污染逐渐成为大众关注的话题之一,而居民的环保意识是影响PM2.5数值的一个重要因素。为了更好地减少和防治PM2.5污染,深入了解居民环保意识对PM2.5污染的影响,对金华市居民环保意识和PM2.5污染现状进行了调研,并利用SPSS20.0软件对两者数值变化进行了相关性分析。结果表明,2013年金华市居民环保意识相比2012年明显提高,PM2.5数值相比2012年有所下降,提升居民环保意识对PM2.5污染有显著的负相关性。针对金华市具体情况提出继续倡导节能减排、绿色低碳,积极推进健康环保新理念,深入农村开展环保宣传等对策,为进一步提高居民环保意识、降低PM2.5提供理论依据。     

我国PM2.5污染特征的研究进展

PM2.5已成为全球大气环境研究热点,近年来国内学者从PM2.5区域污染特征、时空分布特征、化学组成等方面开展了研究.文章从PM2.5质量浓度水平、化学组成两方面对我国PM2.5的污染状况与污染特征进行了综述,并探讨了PM2.5质量浓度水平、化学组成及其对能见度的影响.     

基于CAN总线的PM2.5检测系统

随着人们对空气中PM2.5等污染元素的日益关注,空气质量的好坏已经成为人们生活质量的衡量标准。为了满足用户对PM2.5检测的功能需求,提出了一种基于STM32和CAN总线协议的PM2.5检测系统,该系统通过CAN总线实现数据在各系统中的实时高效传输。对整个系统精度进行试验验证,将PM2.5测量结果与现有测量产品进行对比,实验结果表明,该系统精度高、性能稳定,能快速高效地让用户知晓空气质量,可以应用于家居和工厂等领域。     

北京市空气中PM10与PM2.5的污染水平状况研究

主要对北京市三个采样点的PM10和PM2.5污染水平和时空分布进行了分析.结果表明:市区和西北城区PM10季节性变化一致,郊区与市区和西北城区有所差异,但污染水平最低.PM2 5随PM10上升而上升,但季节性变化与PM10变化不一致.PM2.5/PM10比值在3个采样点都为夏季最高.采样点间对比为:除了PM10西北城区2006年春季超过市区,其它均为市区＞西北城区＞郊区.这些结果可为颗粒物污染的进一步研究提供基础信息和建议.     

中国城市PM2.5影响因素的空间异质性分析

利用2015年全国城市PM2.5监测资料,通过全局最小二乘(OLS)和地理加权回归(GWR)分析影响PM2.5浓度的社会经济和自然因素的空间异质性.结果表明:市区人口对PM2.5浓度有正向影响,而年降水量与PM2.5浓度呈负相关.由于地区经济发展水平不同及地理环境的差异,工业用电量和年均气温对PM2.5影响具有明显的空...     

大气细颗粒物中重金属元素的含量及溶出行为

比较了同一采集周期内大气PM2.5、PM1.0中重金属含量,表明两者对重金属元素的承载能力接近。分析了PM2.5中典型重金属元素的含量,表明其中主要的重金属元素为Pb、Mn、As,含量分别为690.5、460.6、394.8 mg/kg。研究了PM2.5在水中的重金属溶出行为,结果显示PM2.5中Pb、Mn、As在水中的溶出量分别为211.3、236.0.143.4 mg/kg。进一步分析表明,Cd、Hg以水溶性成分为主;Cr、As、Pb以强酸可溶成分为主;Cu、Ni、Mn水可溶与酸可溶组分含量接近。系统分析了大气细颗粒物中重金属元素的含量及溶出行为特征,为大气污染物形成机制、毒理研究、源解析等提供了有益补充。     

基于模糊综合评价蚌埠市PM2.5时空分布规律的研究

针对蚌埠地区PM2.5污染,综合分析空气质量指数历史数据及污染物分级标准,分别构建了二级BP神经网络和模糊综合评价等模型,运用EXCEL、MATLAB等软件编程求解,将环境因素整体作为一个变量因子,研究得出蚌埠市PM2.5的时空分布规律、分区污染评估中各个监测点评估等级等结论.     

邢台市PM2.5污染现状及其防控对策的研究

PM2.5不仅是影响人体健康的可吸入细小颗粒物,而且是形成雾霾天气的主要原因。河北省邢台市今年多次出现雾霾天气,空气质量全国倒数。针对此现状,本文主要围绕PM2.5的成分、特征、来源及其对邢台市污染现状进行较全面的分析研究,有针对性地提出了几点控制PM2.5排放对策。     

脑卒中发病环境因素的定量分析模型

利用提供的数据,在合理假设前提下,给出了脑卒中发病环境因素分析模型．首先采用主成分分析法建立模型,得出影响脑卒中发病的三个因素中,第一类主成分是气温和气压,第二类主成分是相对湿度．其次利用回归分析法得到回归方程,并利用部分数据进行检验．     

潍坊市出口贸易对经济增长的协整分析

根据1994-2008年潍坊市的出口、地区生产总值的数据,在协整检验、Granger因果关系检验计量方法进行协整分析的基础上,运用EG两步法建立二者间的误差修正模型,研究了潍坊市出口贸易与经济增长的关系,并提出相应的政策建议。     

广告投入与销售量的关系

本文利用数学模型来对广告的投放进行一些科学分析,主要涵盖广告的最佳投放时间广告投放策略,同时也对不同的行业、不同的产品、甚至同一产品的不同周期,广告的投放时间、投放程度、以及投放市场的选择进行了阐述。并利用数字模型来检验广告的投放是否达到企业的最佳效果。     

Keeping your audience in mind: applying audience analysis to the design of interactive score reports

Score reports have one or more intended audiences: the people who use the reports to make decisions about test takers, including teachers, administrators, parents and test takers. Attention to audience when designing a score report supports assessment validity by increasing the likelihood that score users will interpret and use assessment results appropriately. Although most design guidelines focus on making score reports understandable to people who are not testing professionals, audiences should be defined by more than just their lack of statistical knowledge. This paper introduces an approach to identifying important audience characteristics for designing computer-based, interactive score reports. Through three examples, we demonstrate how an audience analysis suggests a design pattern, which guides the overall design of a report, as well as design details, such as data representations and scaffolding. We conclude with a research agenda for furthering the use of audience analysis in the design of interactive score reports.     

15门医学课程考试试卷质量评价与探讨

本文通过15门医学课程期末考试试卷质量的分析与评价,认为在运用教育测量技术进行考试质量分析时,必须根据考试的性质、目标及考试具体情况,选择合适的衡量标准作为参照,考试结果才能得以正确解释及应用。     

Picking winners: An empirical analysis of the determinants of educational outcomes in India

We use data from the Young Lives longitudinal survey to analyse the effect of socioeconomic conditions and gender on the educational performance of young children in India. In particular, we use data for standardised scores on two cognitive tests: the Peabody Picture Vocabulary Test (PPVT) and a maths test. Our results show that there are significant gender differences in the way that household wealth affects the educational performance of children. Specifically, boys born into wealthier households perform significantly better in maths than those from worse-off economic backgrounds. The effect of wealth on the PPVT is stronger for girls than it is for boys. The results are robust across a range of specifications. The effect of household wealth on performance differed between the genders, even when we focused our analysis on the bottom 10% and top 10% of the performance distribution. One possible explanation for these differences is parental aspirations. We tested this hypothesis and found that boys from wealthier households with higher parental educational aspirations are positively and significantly associated with higher maths scores. Further analysis showed that the moderating role of parents’ educational aspirations was more pronounced at the top of the test score distribution, an indication that more able children are associated with wealthier and more ambitious parents.     

Relationships between the use of test results and US students’ academic performance

In this study, we examined relationships between the use of test results and US students’ math, reading, and science performance in the Programme for International Student Assessment (PISA) 2009. Based on a literature review, we hypothesized that the 16 items in the PISA school questionnaire, which are related to the use of test results, can be categorized according to 4 factors. We validated this hypothesized factor structure using a confirmatory factor analysis and then obtained composite scores for each factor. As revealed by a multilevel analysis, when student and school demographic variables were controlled for, using test results to hold schools accountable to authority and the public was significantly positively related to students’ performance across all 3 subjects. No statistically significant relationship, however, was detected between students’ performance and the following uses of test scores: informing parents of their children’s performance, providing information for instructional purposes, and evaluating teachers and principals.     

An international validation of the engaged teacher scale

The purpose of this study was to test and validate the Engaged Teacher Scale (ETS) in a Turkish context (ETS-TR). In order to test the construct validity of the ETS, data were collected from 388 teachers in two northeast cities of Turkey. First-order confirmatory factor analysis results supported the 16-item and four-factor model of ETS while second-order confirmatory factor analysis suggested that a single factor was also appropriate for representing teacher engagement. Additionally, four multiple linear regression analyses were conducted to provide further validation evidence. Results showed that subscales of the ETS-TR were found to be positively correlated with teacher self-efficacy. Given our evidence of validity and reliability, we recommend researchers interested in measuring the engagement of Turkish teachers to consider using the ETS-TR. The adaptation of ETS into Turkish also provides a measure for use when conducting research examining cultural comparisons between english-speaking and Turkish teachers.     

高师公共心理学成绩考核模式探讨

考核模式的改革是高师公共心理学课程改革的重要组成部分,要建立优化的高师公共心理学成绩考核模式,必须确立科学的成绩考核的目标体系,建立多种考核方式相互补充的机制,建立系统的成绩考核的管理规范。     

试论正确运用测试反拨作用的重要性

应试教育正向素质教育转轨,这就要求人们对考试在教育中的作用有一个正确的理解,使考试回归到它应有的位置上去．本文通过对一次考试成绩的分析,探讨了考试反拨作用的正确利用对指导学生学法、改进教学方法以及提高测试质量等方面的积极作用．