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71.
介绍了射频标识（RF Tag）技术的基本原理、在战场目标识别领域的应用及部分验证试验的情况。 相似文献
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论述了基于DSP技术的RFID读写器设计方法。在描述RFID系统组成的基础上,给出了读写器的软硬件设计流程。重点阐述了DSP对接收信号的软件处理以及反冲撞功能的实现方法。该读写器已应用于开放式门禁系统中,实际应用结果表明其性能良好。 相似文献
74.
根据美军标MIL-STD-188-141A的规定,8FSK信号的解调是短波自动链路建立(ALE)系统的一项关键技术。通过把图像分割和聚类分析方法应用于8FSK信号的频谱分析,提出了基于模式识别的解调算法。测试结果表明,该算法对白噪声不敏感。 相似文献
75.
数字中频接收机(DIFR)是对中频信号直接采样,其信道化功能由数字正交下变频器和数字滤波器来实现。因此,DIFR适用于接收和处理多载波、多模式信号,可解决很多种信号之间的互通互连问题。本文基于DIFR对动态范围、带宽、自动增益控制和高速信号采集等技术需求,优化设计了一种大动态宽带DIFR,给出了该系统的实现方案、各部分的参数分配及系统设计指标;给出了一种新型的数字自动增益控制(DAGC)实现电路,并提出了其控制算法。 相似文献
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Ruth Rodríguez‐Bermúdez Marta Miranda Inmaculada Orjales María Jos Ginzo‐Villamayor Wajih Al‐Soufi Marta Lpez‐Alonso 《International Journal of Consumer Studies》2020,44(3):206-219
Although the organic sector is still relatively small, the demand for organic food is increasing throughout the world. The characterization of consumers' perception of and attitudes towards organic food is important to enable the development of marketing policies aimed at attracting conventional consumers to the sector. Consumers' behaviour studies must be conducted specifically for different regions and countries as perceptions and attitudes vary across the world. In the present study, a questionnaire was designed for administration to consumers in Galicia (Northern Spain). The questionnaire was administered to 830 consumers in 200 establishments to obtain data about the consumers' perception of and attitudes towards organic food. The survey results showed that one‐third of responders consume organic food and that the typical profile of a consumer of organic food is a middle‐aged, medium‐high class, university‐educated female living in a large village, who shops in supermarkets and preferably consume vegetables, fruits and eggs. Most people who declared that they consume organic products confuse these with home and locally produced food, indicating the potential for growth of the organic sector by providing such consumers with appropriate information. Most consumers (including conventional consumers) have a good opinion of organic food and consider that it is better for health, is of better quality than conventional food and avoid pesticide residues. However, price continues to be a barrier to the consumption of organic produce. Most respondents stated that they would consume more organic food if the price was only between 10% and 30% higher than the conventional equivalent. Finally, organic consumers in Galicia showed positive attitudes towards using local breeds in organic agriculture, both for producing food and for ecotourism and educational activities. Such activities could contribute to conserving breed biodiversity and adding value to organic farming. 相似文献
78.
In this paper, we examine the relationship between volume and return volatility using the transaction data. We introduce transaction and volume imbalance measures to capture the information content of trades. These two information measures are shown to have a strong explanatory power for return volatility and contain incremental information about the asset values over and above that conveyed by the size and frequency of trades. Also, return volatility is significantly correlated with the percentage of trading volume taking place at NYSE. This result suggests that NYSE trades are more informative and contribute more to price discovery. There is evidence that price discovery concentrates in more heavily traded stocks, particularly the Dow Jones Stocks. Finally, return volatility is found to be persistent at the intraday level. The persistence level is higher for less frequently traded stocks. Return volatility also exhibits temporal variations. In particular, return volatility is significantly higher in the opening half-hour for less frequently traded stocks. Thus, stocks with different frequencies of trades may follow different volatility processes. 相似文献
79.
陈欢 《福建商业高等专科学校学报》2014,(1):100-104
现今的网络购物依然无法取代人们日常的超市购物活动。因此,通过在现有的电子商务购物平台基础上,结合二维码、射频识别等物联网技术,设计一套应用于传统生鲜超市的电子购物系统,可以帮助人们快速、便捷地完成传统超市购物的过程。该系统利用二维码存储商品订单信息,方便快捷,便于传递;利用射频标签标识用户商品,自动识别,便于查找。 相似文献
80.