中国农业发展:多重困境与突破路径

作为新农村建设顺利推进的经济基础和逻辑起点,农业发展主要表现为农业增产基础上的农民增收.由于增产和增收、宏观战略和微观目标不一致,在理论和经验上表现出多重困境:主体形成困境、结构调整困境、谈判能力困境和生产效率困境,农业发展的基础不稳定也不牢靠.基于此,将家庭联产承包责任制转变为以家庭专业承包责任制为基本特征的组织创新将至关重要,这个组织演化过程是对农业发展多重困境的一个系统的、积极的回应.     

A machine-learning method for improving crash injury severity analysis: a case study of work zone crashes in Cairo,Egypt

Abstract

The quality of vehicular collision data is crucial for studying the relationship between injury severity and collision factors. Misclassified injury severity data in the crash dataset, however, may cause inaccurate parameter estimates and consequently lead to biased conclusions and poorly designed countermeasures. This is particularly true for imbalanced data where the number of samples in one class far outnumber the other. To improve the classification performance of the injury severity, the paper presents a robust noise filtering technique to deal with the mislabels in the imbalanced crash dataset using the advanced machine learning algorithms. We examine the state-of-the-art filtering algorithms, including Iterative Noise Filtering based on the Fusion of Classifiers (INFFC), Iterative Partitioning Filter (IPF), and Saturation Filter (SatF). In the case study of Cairo (Egypt), the empirical results show that: (1) the mislabels in crash data significantly influence the injury severity predictions, and (2) the proposed M-IPF filter outperforms its counterparts in terms of the effectiveness and efficiency in eliminating the mislabels in crash data. The test results demonstrate the efficacy of the M-IPF in handling the data noise and mitigating the impacts thereof.     

Canadian consumer acceptance of gene-edited versus genetically modified potatoes: A choice experiment approach

In 2016, second-generation genetically modified (GM) potatoes were approved for production and sale in Canada. In this study, we analyze how consumer acceptance of GM potatoes may be affected by various factors, including the trait introduced (i.e., the product benefits), the type of breeding technology used, and the developer of the potato using any technology. We conduct an online survey and use a stated choice experiment to collect data on consumer acceptance of GM and other potatoes in Canada. Random utility models are used to analyze the economic value consumers place on the various attributes of the potatoes. Our results show that consumers are willing to pay more for a health attribute (reduced acrylamide produced when potatoes are fried) and an environmental attribute. Respondents in general need to face discounted prices to buy potatoes created by either gene editing or GM (either transgenic or cisgenic/intragenic) technologies. However, consumers are in general more accepting of the gene editing technology than the GM technologies. Our results also show that government is the most preferred developer of the potatoes, regardless of technology. Results from this study can help guide public and private management of the introduction of new foods when the products are developed with unpopular technologies.     

USB芯片CH375和C51单片机的接口设计

介绍了CH375芯片的性能和工作原理,给出了C51单片机与CH375的接口设计方案,给出了硬件电路设计和存储文件到优盘的软件代码。     

汛情下的城市防洪排涝方案分析 ——以武汉和重庆为例

2020年,长江流域发生了继1998年以后又一次流域性大洪水,作为长江中下游和上游的特大城市,武汉和重庆汛情较为严峻,但应对城市洪涝灾害的方案并不相同.本文以武汉和重庆为例,分析对比汛情下城市内涝防汛中的决策、预警预报与防洪调度、水利设施等方面情况,以期对城市洪涝灾害研究与防治问题有所借鉴.     

回顾与展望:2000-2004年的《旅游学刊》

本文对2000-2004年《旅游学刊》刊登的481篇论文进行了分类统计,并着重介绍了旅游业产业地位和作用、可持续发展和生态旅游、景区保护与管理、饭店和旅行社、旅游规划、旅游经济分析、区域旅游业发展、旅游市场与旅游者行为、研究综述等9个主题的重要文献,以此追踪近年中国旅游研究的动态,并反映《旅游学刊》为促进我国旅游业发展和旅游研究进步而做的努力。     

“60前”消费者玩转高科技产品基于反向代际影响调节作用的实证研究

针对1960年以前出生的50岁以上、居住在城市的消费者,研究了不同年龄、教育背景和月收入水平的年长消费者在高科技产品购买意愿方面的差异性,以及决策风格对于高科技产品购买意愿的影响。此外,本文还探讨了年轻一代对于年长消费者的影响,即反向代际影响对于研究人群的决策风格与高科技产品购买意愿之间关系的调节作用。本文通过研究发现不同年龄、教育背景和月收入水平的年长消费者在面对高科技产品时的购买意愿不同。同时,消费者的购物决策风格也会影响到消费者对于高科技产品的购买意愿。此外,反向代际影响对于决策风格和购买意愿之间的关系具有正向调节作用。最后,本文还根据研究结果给出了相应的管理建议。     

论现代大学教师人文素养的提升与人文精神的构建

教师的人文素养与人文精神是提升学校教育品位、提高学生人文精神水平的主要因素和重要条件.提升现代大学教师人文素养,构建现代大学教师人文精神,必须在文化、精神、制度等方面进行创新.     

对高校内部经济责任审计的思考

高校财务管理是高校管理工作的重要组成部分。当前,高校内部经济责任审计存在的主要问题是,经济责任认识及定位存在误区,目标责任界定不清及执行不到位,审计方式单一,对审计结果重视不够。落实高校内部经济责任审计,应建立经济责任审计联席会议制度,整合资源形成合力;明确责任界定,建立科学的经济责任评价依据;关注管理过程,突出经济责任审计特点;以经济责任为基础,构建评价指标体系;灵活运用审计方式,强化审计结果的运用。     

物权立法:完善土地物权体系的契机

2005年7月10日,物权法草案由全国人大常委会向全社会发布,广泛征求意见。物权法立法与土地管理工作密切相关,我们应当深入思考,认真研究,积极参与物权法草案征求意见活动,提出科学、合理的立法建议。物权制度历来都是国家法律制度的重要内容在我国,早在商朝的法律中,就有关于土地所有权制度的规定。此后,从西周一直到明清,物权制度特别是土地物权法律制度,始终是我国封建法律制度的重要内容之一。事实上,几千年中华文明,一直是伴随着土地制度的革新和演进向前发展的。但由于中华法系“诸法合一”、“民刑不分”,我国封建社会一直没有形成独…