Research on Prediction of Sentiment Trend of Food Safety Public Opinion

Emotion has a nearly decisive role in behavior, which will directly affect netizens’ views on food safety public opinion events, thereby affecting the development direction of public opinion on the event, and it is of great significance for food safety network public opinion to predict emotional trends to do a good job in food safety network public opinion guidance. In this paper, the dynamic text representation method XLNet is used to generate word vectors with context-dependent dependencies to distribute the text information of food safety network public opinion. Then, the word vector is input into the CNN-BiLSTM network for local semantic feature and context semantic extraction. The attention mechanism is introduced to give different weights according to the importance of features, and the emotional tendency analysis is carried out. Based on sentiment analysis, sentiment value time series data is obtained, and a time series model is constructed to predict sentiment trends. The sentiment analysis model proposed in this paper can well classify the sentiment of food safety network public opinion, and the time series model has a good effect on the prediction of food safety network public opinion sentiment trend. .

A Preliminary Study of Just-in-Time Methods for a Seamless Public Transportation Information Framework

A seamless multimodal transit system has been a goal for transportation planners and users. Owing to the developments of advanced public transportation and telecom technologies such as automatic vehicle location (AVL) and real-time passenger information system, key just-in-time (JIT) concepts can now be realized in process design and coordinated scheduling to shape a seamless multimodal transit system. JIT refers to a production system that times both movements of goods during production and delivery from suppliers together. It meets the same logic for seamless multimodal services. Therefore, this study innovatively analyzes possible public transportation technologies for JIT uses;moreover, to layout the possible application frame-work of a transportation technology based JIT multimodal transit system for main station area in Taipei city. With this innovative framework, multimodal transit services can deliver to the right place at right time.

一种分析Timed-Release公钥协议的扩展逻辑

在Coffey和Saidha提出的CS逻辑 (CS逻辑将时间与逻辑结构相结合 ,可用于形式化分析Timed release公钥协议的时间相关性秘密的安全性 )的基础上 ,提出了CS逻辑的扩展逻辑 ,它更好地反映了Timed release公钥协议的特性 ,并对一个协议实例进行了有效的形式化分析 .

A Bias-Free Time-Aware PageRank Algorithm for Paper Ranking in Dynamic Citation Networks

The process of ranking scientific publications in dynamic citation networks plays a crucial rule in a variety of applications. Despite the availability of a number of ranking algorithms, most of them use common popularity metrics such as the citation count, h-index, and Impact Factor (IF). These adopted metrics cause a problem of bias in favor of older publications that took enough time to collect as many citations as possible. This paper focuses on solving the problem of bias by proposing a new ranking algorithm based on the PageRank (PR) algorithm;it is one of the main page ranking algorithms being widely used. The developed algorithm considers a newly suggested metric called the Citation Average rate of Change (CAC). Time information such as publication date and the citation occurrence’s time are used along with citation data to calculate the new metric. The proposed ranking algorithm was tested on a dataset of scientific papers in the field of medical physics published in the Dimensions database from years 2005 to 2017. The experimental results have shown that the proposed ranking algorithm outperforms the PageRank algorithm in ranking scientific publications where 26 papers instead of only 14 were ranked among the top 100 papers of this dataset. In addition, there were no radical changes or unreasonable jump in the ranking process, i.e., the correlation rate between the results of the proposed ranking method and the original PageRank algorithm was 92% based on the Spearman correlation coefficient.

Bluetooth as a traffic sensor for stream travel time estimation under Bogazici Bosporus conditions in Turkey

Travel time estimation is an integral part of Intelligent Transportation Systems, and has been an important component in traffic management and operations for many years. Travel time, being spatial in nature, requires spatial sensors to measure it accurately. Bluetooth is emerging as a promising technology for the direct measurement of travel time, and is reported in a few studies from homogenous traffic conditions. At the same time, there have been no studies on the applicability of Bluetooth for travel time estimation in heterogeneous traffic seen in Istanbul and even that Turkey. Bluetooth data collected from a busy urban road in Istanbul city have been analyzed and the penetration rate was found to be about 5 %. Two wheelers and light motor vehicles have been detected using the Bluetooth sensor and the data have been extrapolated to estimate travel times of other classes of vehicles. The study developed linear relationships between speeds of different classes of vehicles through weighted linear regression methods and were used for the estimation of stream travel time. The results obtained were promising and show that Bluetooth is a cost-effective technology for estimation of travel time for heterogeneous traffic conditions.

Does Monetary Support Increase the Number of Scientific Papers？ An Interrupted Time Series Analysis

Purpose： One of the main indicators of scientific production is the number of papers published in scholarly journals. Turkey ranks 18th place in the world based on the number of scholarly publications. The objective of this paper is to find out if the monetary support program initiated in 1993 by the Turkish Scientific and Technological Research Council （TUBITAK） to incentivize researchers and increase the number, impact, and quality of international publications has been effective in doing so.Design/methodology/approach： We analyzed some 390,000 publications with Turkish affiliations listed in the Web of Science （WoS） database between 1976 and 2015 along with about 157,000 supported ones between 1997 and 2015. We used the interrupted time series （ITS） analysis technique （also known as ＂quasi-experimental time series analysis＂ or ＂intervention analysis＂） to test if TOBITAK＇s support program helped increase the number of publications. We defined ARIMA （1,1,0） model for ITS data and observed the impact of TOBiTAK＇s support program in 1994, 1997, and 2003 （after one, four and 10 years of its start, respectively）. The majority of publications （93%） were full papers （articles）, which were used as the experimental group while other types of contributions functioned as the control group. We also carried out a multiple regression analysis.Findings： TUBITAK＇s support program has had negligible effect on the increase of the number of papers with Turkish affiliations. Yet, the number of other types of contributions continued to increase even though they were not well supported, suggesting that TUBITAK＇s support program is probably not the main factor causing the increase in the number of papers with Turkish affiliations. Research limitations： Interrupted time series analysis shows if the ＂intervention＂ has had any significant effect on the dependent variable but it does not explain what caused the increase in the number of papers if it was not the intervention. Moreover, except the＂intervention＂, other ＂event（s）＂ that might affect the time series data （e.g., increase in the number of research personnel over the years） should not occur during the period of analysis, a prerequisite that is beyond the control of the researcher. Practical implications： TUBITAK＇s ＂cash-for-publication＂ program did not seem to have direct impact on the increase of the number of papers published by Turkish authors, suggesting that small amounts of payments are not much of an incentive for authors to publish more. It might perhaps be a better strategy to concentrate limited resources on a few high impact projects rather than to disperse them to thousands of authors as ＂micropayments.＂ Originality/value： Based on 25 years＇ worth of payments data, this is perhaps one of the first large-scale studies showing that ＂cash-for-publication＂ policies or ＂piece rates＂ paid to researchers tend to have little or no effect on the increase of researchers＇ productivity. The main finding of this paper has some implications for countries wherein publication subsidies are used as an incentive to increase the number and quality of papers published in international journals. They should be prepared to consider reviewing their existing support programs （based usually on bibliometric measures such as journal impact factors） and revising their reward policies.

Accessibility Comparison and Spatial Differentiation of Xi’an Scenic Spots with Different Modes Based on Baidu Real-time Travel

A study of the accessibility of a city’s scenic spots via different travel modes can contribute to optimization of tourism-related transportation while improving tourists’ travel-related satisfaction levels and advancing tourism. We systematically analyzed the accessibility of 56 scenic spots in Xi’an City, China, via car and public transport travel modes using the real-time travel function of the Baidu Maps API(Application Programming Interface) along with spatial analysis methods and the modal accessibility gap index of scenic spots. We obtained the following results. First, maximum and minimum travel times using public transport exceeded those using cars. Moreover, the accessibility of scenic spots via cars and public transport presented a circular spatial pattern of increasing travel time from the center to the periphery. Contrasting with travel by public transport, car travel showed a clear time-space compression effect. Second, accessibility of the scenic spots via cars and public transport showed some spatial heterogeneity, with no clear advantages of car accessibility in the central urban area. However, advantages of car accessibility were increasingly evident moving from the center to the periphery. Third, whereas the correlation of the modal accessibility gap index of scenic spots in Xi’an with global space was significantly positive, local spatial interdependence was only evident in some inner city areas and in marginal areas. Moreover, spatial heterogeneity was evident in two regions but was insignificant in other areas, indicating that the spatial interdependence of the modal accessibility gap index in most scenic spots was not apparent in terms of the overall effect of public transport routes, road networks, and the distribution of scenic spots. The improvement of public transport coverage in marginal areas and the optimization of public transport routes in central urban areas are essential tasks for improving travel using public transport in the future.

择时训练理论下公安院校警察体能课程时段设置研究

择时训练理论依托运动生物学的核心——生物节律,通过更加符合人体生物节律的运动时段进行训练,同时公安院校承载着为国家培养预备警官的重要任务,更加突出在公安院校警察体能课程中进行课程时段设置的重要性。本研究基于择时训练理论,旨在探讨公安院校警察体能课的时段设置对学员体能训练效果的影响。为此,本研究采用文献资料法、专家访谈法、实验法等对公安院校警察体能课程时段设置进行研究,并结合择时训练理论给出切实可行的训练方案,从而为公安院校学员在体能训练方面提供研究思路。

public—key密码系统破裂问题浅介

任何一个公开密钥密码系统(pkcs)可能在非确定的多项式时间内破裂,那么,最低限度,在确定的多项式时间内pkcs则不应当破裂,证明意味着,已知系统在N≠NP时是安全的.简略地说:pkcs的“破裂问题”是一个明文信息M的计算问题,而M又是由未知当前脱密密钥的密码C编码的.典型的计算问题,转换成多项式时间的等值判定性问题,而计算问题的复杂性结构是结合判定问题的分类来度量的.从而,确立了密码复杂性转换成精确结构的论点.

张恨水北京叙事中的“公共时间”

现代通俗小说是反映社会的一座富矿。20世纪二三十年代,北京的商业活动日益活跃、娱乐业逐渐兴旺,北京市民的生活节奏加快,社会交往和互动增多。为进行公共娱乐活动,市民们共享公共时间,娱乐活动的时间安排也更集中。通俗小说大家张恨水的北京叙事对北京公共时间的设定与反映,彰显了当时北京城市生活的现代特质,成为研究现代通俗小说社会学价值的典型范例。

重大突发公共卫生事件中的方舱医院建设情景重建研究

方舱医院建设是应对各类重大突发公共卫生事件的一项重要举措。现有研究大多从医学或政府管理视角定性地探讨方舱医院发挥的重要作用,还鲜有从情景重建视角研究方舱医院床位扩容的最优时空分布。本文首先构建针对重大突发公共卫生事件演化的SEIHRD模型,继而将方舱医院床位扩容问题构建为有限应急资源分配组合优化模型并设计免疫优化算法进行求解。测试结果显示,本文所给出的方舱医院床位扩容时空分布优化方案,能够对重大突发公共卫生事件中的方舱医院建设情景进行有效重建。方舱医院床位数量及其时间节点设置对累计感染者人数具有显著影响,这表明在疫情暴发初期尽早设立方舱医院,能够有效提升收治率、减少总感染人数。同时也要注意,应急救援资金投入存在阈值效应,需要设计合理的方舱医院床位扩容方案以避免应急预算资源的过度浪费。

分数卷积灰色预测模型及其在信息传播中的应用

通过构造累加生成卷积序列的离散卷积运算实现了数据序列的累加生成,并推广到分数阶卷积幂以实现分数阶累加生成。离散序列卷积运算统一了累加生成和累减生成,给定阶数即可生成相应的卷积序列。引入离散卷积运算,可以从信号处理的角度来理解累加生成。累加生成系统可视为一个线性滤波器,累加卷积序列的本质是滤波器的单位冲击响应,卷积运算对应滤波过程。在分数累加卷积序列的基础上构建了分数阶灰色预测模型。最后给出数值实验和信息传播中的实际应用案例验证理论的正确性和方法的有效性。

《印度斯坦时报》对华舆论战:以“印太”语境下的策略性叙事为例

[研究目的]当前,在中印边境争端凸显、印度将中国塑造为假想敌、借加入“印太”战略提升竞争筹码的背景下,印度主流媒体对华舆论攻势愈演愈烈,研究“印太”语境下的策略性叙事对中国夺取舆论战主动权意义重大。[研究方法]通过定量与定性相结合的方法,利用语义网络的内容分析和话语分析考察《印度斯坦时报》对华舆论战的阶段性叙事框架和策略性文本重构。[研究结论]研究发现,印媒利用策略性叙事进行的舆论战兼具政策叙事、体系叙事和身份叙事的框架特征,善用利益捆绑、情感操纵、科学伪装的叙事文本。中国对印舆论交锋应着力拓展叙事对象、提升叙事技巧、设置叙事议程,夺取舆论传播的制度性话语权。

基于HPO-LSTM的公交周转时间预测

公交周转时间的准确预测是公交智能排班的基础和前提,是制定行车时刻表的关键。为提高公交周转时间的预测精度,提出了基于猎人猎物优化长短时记忆神经网络(HPO-LSTM)的公交周转时间预测模型,将长短时记忆神经网络(LSTM)中的超参数(隐含层节点数、迭代循环数以及初始学习率)映射为猎人猎物优化算法(HPO)种群的位置;以LSTM模型预测值与真实值产生的均方根误差E_(RMS)作为种群适应度函数,优化种群位置,实现LSTM神经网络超参数寻优;用最优超参数构建LSTM神经网络,进行公交周转时间预测。采用某市公交1号线数据对模型进行验证分析,结果表明:相比于BP、LSTM、FA-BP、HPO-BP模型,HPO-LSTM模型平均绝对百分比误差E_(MAP)分别降低10.44%、4.00%、3.61%、2.04%。

美国公共图书馆夜间服务实践调研及启示

文章选取美国排名前25的公共图书馆作为研究对象,对美国公共图书馆夜间服务实践展开网络调研,从服务群体、服务空间和读者活动三方面分析了美国公共图书馆的夜间服务现状及服务特点。基于研究结果阐述了对我国公共图书馆夜间服务高质量发展的启示:创新思维,积极策划服务项目;细分受众,精准把控用户需求;吸引社会力量,加强跨界融合;深挖地域特色文化,打造夜间经济文化IP。

研究性教学方法在非全日制公共卫生硕士流行病学教学中的效果评价

目的:探讨研究性教学方法在非全日制公共卫生硕士流行病学教学中的应用效果。方法:将复旦大学公共卫生学院2017级、2018级非全日制公共卫生硕士研究生作为对照组,采用传统教学方法;2019级、2020级非全日制公共卫生硕士研究生作为试验组,采用研究性教学方法,即知识讲授结合案例讨论。比较两组学生的教学效果。结果:试验组学生的理论成绩和科研成绩均显著高于对照组,差异具有统计学意义(P<0.05)。结论:在流行病学教学中应用研究性教学方法能显著提高教学效果,并增强学生的科研实践能力。

顾及动态交通路况的高速公路消防救援可达性评估

消防救援可达性评估是优化消防站布局、提升消防服务水平的重要前提。现有研究主要聚焦于面形区域消防救援可达性评估,且多分析消防救援在距离上的可达性,暂无研究以线形、半封闭特征的高速公路为对象,并考虑实时路况来分析消防救援在时间上的可达性。通过划分不同消防救援可达区间,基于时间加权方法建立高速公路消防救援可达性指标评估模型。以长沙市为例,收集了11455个高速公路区间点作为消防救援需求点,53座消防站作为消防救援供给点,并调用在线地图(如百度地图)实时路况数据来模拟消防救援行程时间。结果表明,长沙市高速公路消防救援总体可达性为48.46,消防救援服务水平为“中”,该地区高速公路应对火灾风险能力不强,有必要增加高速公路沿线消防站数量。该研究可为优化高速公路沿线消防站布局提供理论和方法支撑。

文化综合体全时开放的公共空间设计研究——以深圳为例

全时开放公共空间设计是影响文化综合体公共空间层次和市民行为活动的重要因素,注重其设计质量对于城市公共空间和市民日常活动都具有重要意义。本文从公共活动的相关理论出发,探讨深圳文化综合体全时开放的公共空间承载市民活动的机制。从激活市民日常公共活动的角度,综合深圳市具有代表性的案例与实践,解析新趋势下文化综合体全时开放公共空间的具体设计方法,反思设计结果,提出了边界消隐、连接加强、尺度适宜、功能复合、流线立体、激发活力的设计策略。

航空货物分类分级安检模式安全性分析

为保障航空安检环节安全高效,部分机场探索实施航空货物分类分级安检模式。研究以安全性为目标,综合考虑安检错误报警概率及货物安检处理时间,分析传统安检模式和分类分级安检模式在安全性方面的差异。使用错误放行概率作为衡量安检模式安全性的指标,利用目视搜索-决策模型分析安检员判图过程,为两种安检模式建立非线性规划模型。研究显示:与传统安检模式相比,分类分级安检模式中高风险货物的比例m在(0,0.45)内才能提高系统安全性,且m最优取值为0.12;与传统安检模式相比,分类分级安检模式在货量较大、对安检处理时间较为敏感或是对安检错误报警概率容忍度较高时更能显著提高系统安全性。

不确定境遇下教育公共性的重塑

公共性与私人性相对,包含公开呈现、理性对话、共商共享、多元包容等要素。公共性是现代教育的重要特征,对个体和社会发展具有重要意义和作用。然而,在充满不确定性的现代社会,教育存在公共性缺失的风险,学生陷入了身份焦虑、人际关系冷漠和公共意识淡薄的困境。这些现象既受到不确定社会“他者”的消失、公共空间异化和消费崇拜等因素的影响,又与共同体的消逝及其引发的个体化困境密切相关。基于流动现代性理论,重塑教育公共性需重建校园公共生活,重构学生公共意识,实施“对他者负责”的道德教育。