基于超声波测距的实时路况信息采集系统

基于超声波测距原理,通过AVR单片机芯片计算出道路车辆的实时速度以及车流量。采集到数据后,通过无线模块NRF24L01发送到PC端,在PC上用VB开发上位机,从而显示出实时曲线,道路信息。介绍了系统的硬件及其软件的整体设计理念,注意事项,同时给出了该系统的应用前景。     

一类具有强奇性的矩阵型偏微分方程的正解的存在性

研究矩阵型强奇异偏微分方程 其中,Ω⊂Rⁿ是有界开集,M（x）是定义在Ω上的实对称矩阵,-p<-1,0 < q < 1,λ>0是参数,f（x）∈L¹（Ω）,f（x）>0 a.e.in Ω。证明,如果存在u₀ ∈H₀¹（Ω）满足∫_Ωf（x）|u₀|^1-pdx <+∞,则对任意的λ>0上述方程都有正H₀¹-解,即慢速解。我们注意到,对于奇异方程,古典解即C²（Ω）∩C（Ω）解不一定是H₀¹（Ω）解。     

人口老龄化及其城市社区老年体育的发展

在分析我国人口老龄化背景及应对路径的基础上,结合南昌市社区老年体育状况,论述体育锻炼在应对人口老龄化挑战中的优势,研究认为发展社区老年体育是应对人口老龄化的重要途径,并在此基础上就发展社区老年体育工作,提出老年体育应成为社区体育工作重点、社区体育设施应考虑老年人的健身需求、切实加强老年人科学健身指导服务工作等几点建议.     

Information retrieval in the workplace: A comparison of professional search practices

Legal researchers, recruitment professionals, healthcare information professionals, and patent analysts all undertake work tasks where search forms a core part of their duties. In these instances, the search task is often complex and time-consuming and requires specialist expertise to identify relevant documents and insights within large domain-specific repositories and collections. Several studies have been made investigating the search practices of professionals such as these, but few have attempted to directly compare their professional practices and so it remains unclear to what extent insights and approaches from one domain can be applied to another. In this paper we describe the results of a survey of a purposive sample of 108 legal researchers, 64 recruitment professionals and 107 healthcare information professionals. Their responses are compared with results from a previous survey of 81 patent analysts. The survey investigated their search practices and preferences, the types of functionality they value, and their requirements for future information retrieval systems. The results reveal that these professions share many fundamental needs and face similar challenges. In particular a continuing preference to formulate queries as Boolean expressions, the need to manage, organise and re-use search strategies and results and an ambivalence toward the use of relevance ranking. The results stress the importance of recall and coverage for the healthcare and patent professionals, while precision and recency were more important to the legal and recruitment professionals. The results also highlight the need to ensure that search systems give confidence to the professional searcher and so trust, explainability and accountability remains a significant challenge when developing such systems. The findings suggest that translational research between the different areas could benefit professionals across domains.     

Meta-Circuit machine: Inferencing human collaborative relationships in heterogeneous information networks

Human collaborative relationship inference is a meaningful task for online social networks and is called link prediction in network science. Real-world networks contain multiple types of interacting components and can be modeled naturally as heterogeneous information networks (HINs). The current link prediction algorithms in HINs fail to effectively extract training samples from snapshots of HINs; moreover, they underutilise the differences between nodes and between meta-paths. Therefore, we propose a meta-circuit machine (MCM) that can learn and fuse node and meta-path features efficiently, and we use these features to inference the collaborative relationships in question-and-answer and bibliographic networks. We first utilise meta-circuit random walks to obtain training samples in which the basic idea is to perform biased meta-path random walks on the input and target network successively and then connect them. Then, a meta-circuit recurrent neural network (mcRNN) is designed for link prediction, which represents each node and meta-path by a dense vector and leverages an RNN to fuse the features of node sequences. Experiments on two real-world networks demonstrate the effectiveness of our framework. This study promotes the investigation of potential evolutionary mechanisms for collaborative relationships and offers practical guidance for designing more effective recommendation systems for online social networks.     

XF0362切削液系统皂化控制的应用研究

切削液的皂化是一种普遍现象,尤其在切削液浓度与温度变化较大时其皂化现象就更加明显.而XF0362切削液为了解决温度与浓度对切削液皂化作用的影响,在添加抗皂化剂P-01后改变其性能,从而解决了皂化现象.     

多功能红外语音体温计的设计

介绍一种具有非接触体温测量的新型多功能红外语音体温计。该体温计基于普朗克黑体辐射定律和高性能红外温度传感器,采用单片机数据处理和语音处理、LCD显示等技术,能够对体温进行有效准确的非接触测量。该体温计功耗低,测量速度快,并有年历、语音报温和报时,安全可靠,使用方便等特点,可广泛应用于日常保健及医学测试领域。     

Premiums,announcement returns and desperation in high tech mergers: A growth options analysis

We examine the announcements of high tech mergers using a relatively new proxy for growth options we call “growth to book.” We find this adds significantly to help explain the premiums paid and announcement period abnormal returns when acquiring tech targets. Higher synergies are expected by managers and investors when targets have low growth options and acquirers have high growth options, resulting in higher premiums paid and either less negative or more positive abnormal returns. However, we find significant variation in the results by the relative size of the target and when low growth to book (GTB) firms acquire. While high GTB acquirers tend to pay more in premiums, low GTB acquirers can pay higher premiums and receive some of the most negative returns at announcement. We find evidence some acquisitions are motivated by desperation as these acquirers have the lowest GTB and do a disproportionate number of the relatively largest deals, receiving the worst abnormal returns at announcement.     

X波段宽带低噪声放大器设计

介绍与实现了一种X波段宽带低噪声放大器（LNA）。该放大器选用NEC公司的低噪声放大管NE3210S01（HJFET）,采用微带分支线匹配结构和两级级联的方式。利用ADS软件进行设计、优化和仿真。最后研制的放大器在10-13GHz范围内增益为（21.5±1）dB,噪声系数小于2 dB,驻波比小于1.8。