基于改进YOLOv4的行人检测算法

针对YOLOv4算法在行人检测中精度低,实时性差的问题,提出一种基于YOLOv4的改进算法.首先将MobileNetv2作为主干网络,在减少参数量的同时保证其特征提取能力,同时在MobileNetv2中加入Bottom-up连接,减少浅层信息的丢失;然后在特征融合网络嵌入卷积模块的注意力机制模块(convolution...     

Estimated HCFC-142b emissions in China: 2000–2050

1-Chloro-1,1-difluoroethane(HCFC-142b)was both ozone depleting substance under restriction of the Montreal Protocol on Substances that Deplete the Ozone Layer(Montreal Protocol)and potent greenhouse gas with high GWP.Controlling its emissions in China will contribute to both mitigating climate change and protecting ozone.A national emission inventory of HCFC-142b for China during 2000–2012 was established and projected to2050 based on the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the Montreal Protocol,showing that(i)in contrast to the downward trend revealed by existing researches,HCFC-142b emissions kept increasing from 0.1 kt/y in 2000 to the peak of 14.4 kt/y in2012,making China a crucial contributor to global HCFC-142b emissions and(ii)for future emission projections,a continuous increase from 14.9 kt/y in 2013 to 97.2 kt/y in2050 was anticipated under the business-as-usual(BAU)scenarios,while a reduction of about 90%of the projected BAU emissions would be obtained by fulfilling the Montreal Protocol,namely an accumulative mitigation of 1578kt HCFC-142b from 2013 to 2050,equal to 103 kt ODP and 3504 Tg CO2emissions.Emissions from each province in 2012 were also estimated to identify key emission areas.Among the 31 mainland provinces in China(Hong Kong,Macao,and Taiwan were not included),Jiangsu,Zhejiang,Shandong,and Guangdong had the highest emission ratesin 2012(2.06,1.85,1.52,and 1.04 kt/y,respectively);Zhejiang,Jiangsu,and Shanghai exhibit the strongest emission strength(0.83,0.59,and 0.54 t/km2,respectively),much higher than the average national level of 0.33t/km2.     

听力加工模式在英语专业基础阶段听力教学中的实施

以“自下而上”，“自上而下”，以及“交互性”加工法为理论框架，通过分析英语专业基础阶段学生的听力理解障碍，探讨了如何在听力教学中运用三种信息加工法，有效提高教学质量的问题。     

人工智能研究中的Bottom-up方法和Top-down方法

将人工智能研究在方法上区分为Bottom-up派和Top-down派,并且分别叙述了这两种方法的哲学、历史和成果。主张两种方法走向极端是不可取的,人工智能研究要寻找两种方法的结合点,才可能避免任何一种极端方法所导致的研究复杂性。     

试论英语语音教学的内容及方式

语音教学不仅仅是教授单个音位的发音,它还包括节奏和语调等重要因素.在中国,采用自下而上法授语音,把语音教授贯彻于各个课型中,是行之有效的语音学习方法.     

A pragmatic account of mechanistic artifact explanation

A mechanistic artifact explanation is an explanation that accounts for an artifact behavior by describing the underlying mechanism. The article shows that there are different kinds of mechanistic artifact explanation: top-down and bottom-up explanation, and I also distinguish between less and more inclusive top-down explanations. To illustrate these different kinds of explanation, the behavior of a simple, fictional artifact is explained in different ways. I defend that which explanation is ideal, depends on pragmatic factors (e.g., the background knowledge of the explainee and the specific goal for which the explanation will be used). For each kind of explanation, the situations, goals and interests for which it is most appropriate are specified, resulting in a pragmatic theory of mechanistic artifact explanation. This theory is compared to Jeroen de Ridder’s account of the pragmatics of mechanistic artifact explanation.     

Rehabilitating theory: refusal of the ‘bottom-up’ construction of scientific phenomena

In this paper I inquire into Bogen and Woodward’s (1988) data/phenomena distinction, which in a similar way to Cartwright’s construal of the model of superconductivity (1995)—although in a different domain—argues for a ‘bottom-up’ construction of phenomena from data without the involvement of theory. I criticise Bogen and Woodward’s account by analysing their melting point of lead example in depth, which is usually cited in the literature to illustrate the data/phenomenon distinction. Yet, the main focus of this paper lies on Matthias Kaiser’s (1995) case study of the plate tectonic revolution, the most extensive case study that has been put forth to support the bottom-up construction of phenomena. On the basis of new historical evidence, which has been overlooked not only by Kaiser but also by the entire historical literature on the plate tectonic revolution, I demonstrate that phenomena are not constructed from the bottom-up but rather, admittedly counter-intuitively, from the top-down.