基于Geortzel算法实现高效多路DTMF检测

基于戈泽尔算法,可得到一种DTMF检测的高效算法,本文描述了这种算法及使用该算法在TMS320S50上实现的30路DTMF检测器。     

海面低仰角数字微波通信系统性能及体制分析

本文介绍了海面低仰角数字微波通信系统的特点，对海面电波多径衰落进行了理论计算，指出了通信系统抗衰落的方法和手段，并给出了一种抗衰落通信系统在海面通信试验中的测试数据。     

Seeing history: a visual assessment of the historic-grounding of Old Western tourist towns

Despite the significant role that the visual plays in the experience of tourism, few studies have specifically examined the visual appearances of heritage tourist destinations. This study sought to analyze how historically grounded the visual appearances were of two heritage tourist towns in the state of Arizona: Tombstone and Jerome. These towns were both mining towns that experienced historic booms during the days of the American Old West and survive today as tourist destinations. This study utilized a detailed visual comparison of historic and contemporary town photographs in order to assess the relative historic-grounding of building exteriors and streets. It also incorporated the findings of interviews with tourists and town residents regarding their perceptions of visual historic-grounding. Study findings offered a means to assess and compare visual historic-grounding. Additionally, they suggested that while visual historic-grounding was important to visitors, it was one of several factors influencing their perceptions of the town's historic appearance: visual appeal, personal reflections, engaging activities, and previous visitor expectations of the American Old West (often grounded in filmic-representations) worked together to visually communicate a general impression of history within each town.     

Assessing greenhouse gas emissions from electric vehicle operation in Australia using temporal vehicle charging and electricity emission characteristics

ABSTRACT

Significant interest exists in the potential for electric vehicles (EVs) to be a source of greenhouse gas (GHG) abatement. In order to establish the extent to which EVs will deliver abatement, however, a realistic understanding of the electricity and transport sector GHG emissions impacts arising from different approaches to integrating EVs into the power system is required. A key issue in this regard is the extent to which GHG emissions are a function of where and when EV charging will be enabled (or disabled) by the provision of recharging infrastructure and implementation of charging management strategies by the electricity industry. This article presents an investigation of the GHG emissions arising from electricity and gasoline consumption by plug-in hybrid EVs under a range of standard EV-power system integration scenarios. An assessment framework is presented, and GHG emissions from EV use are assessed for the New South Wales (NSW) and South Australian (SA) pools of the Australian National Electricity Market (NEM) using retrospective electricity system generation data for 2011. Results highlight that there is a range of possible outcomes depending on the integration scenario and emissions accounting approach used. This range illustrates value of a temporally explicit assessment approach in capturing the temporal alignment of electricity sector emission intensity and EV charging. Results also show the importance of a clean electricity generation mix in order for EVs to provide a GHG abatement benefit beyond what would be achieved by a hybrid (but non-plug-in) vehicle. The extent to which overnight charging in NSW is observed to produce higher emissions relative to unmanaged charging also illustrates a possible trade-off between GHG emissions and benefits for electricity industry from EV charging at times of low demand.     

Interplay between ethanol and electric vehicles as low carbon mobility options for passengers in the municipality of São Paulo

The Brazilian cities as well as many of the large urban centers in the world continue to expand, increasing the demand for mobility and transport, while, at the same time, the same cities are investing in greenhouse gas (GHG) mitigation to avoid climate change. Brazil's urbanization rate increased from 26% in 1940 to almost 70% in 1980. During this period, the Brazilian population tripled and the urban population multiplied by seven. In 2010, the transport sector in São Paulo accounted for 71% of the total emissions released by the energy sector. Ethanol has been considered a fuel with less greenhouse gas emissions, when compared with fossil fuels. However, ethanol production would have to double to meet the expected demand. Electric vehicles (EVs) market is expanding around the world, and is also an option to reduce the transport emissions, if powered by clean electricity. To assess whether the adoption of EVs might bring more benefits than the current ethanol, we develop prospective scenarios supported by the Long-range Energy Alternatives Planning (LEAP) simulation tool, taking a bottom-up tank-to-wheel approach to consider the CO₂ emissions of car in São Paulo. The scenario considering a substitution of 25% of gasoline-powered cars by EV in 2030 showed a reduction in energy consumption and CO₂ emissions, around 15% and 26% respectively in that year in comparison with 2015. We discuss the interplay between ethanol and EV, also considering emission coefficients from life cycle analysis conducted in Brazil, and concluded EV will have higher positive impact on climate change mitigation than ethanol.     

A theoretical framework of electronic word-of-mouth against the backdrop of social networking websites

This study proposed and tested a theoretical framework that explains electronic word-of-mouth (eWOM) against the backdrop of social networking websites (SNWs), which have gained substantial popularity among travelers. In particular, a United States (US) nationwide online survey was conducted and nine hypotheses were tested. The findings suggest that willingness to share knowledge and switching costs are positively related to eWOM communication. In addition, customer value (utilitarian) has positive relationships with willingness to share knowledge, perceived security, and switching cost, while customer value (hedonic) has positive relationships with willingness to share knowledge and switching costs. Last but not least, the findings indicate that perceived security does negatively impact eWOM. In light of the major findings, the article sets forth strategic implications for travel-related social networking websites.     

Empowerment in hospitality organizations: Customer orientation and organizational support

Although empowering employees has often been prescribed as an efficient strategy for hospitality organizations, the strategy alone cannot ensure success. Individual and organizational factors should be considered to increase employees’ perception of empowerment. This study examines the impact of employees’ customer orientation and organizational factors on the employee empowerment perceptions. Our findings, based on a survey of 203 guest contact employees, suggest that organizations should hire customer oriented people, guide them with service training, provide a reward system, and facilitate service standards communication in order to increase perceived empowerment. Implications of these findings for hospitality service managers are discussed.     

浅谈体育教育对学生心理健康的影响

体育教学是学校素质教育的重要组成部分,它不仪可以促进学生的身体健康,也可以促进学生的心理健康。体育教学在当代学生心理健康教育中应发挥着不可替代的特殊作用。     

科技哲学的现状及其在传播过程中面临的问题研究

科技哲学是以现代科技的变化规律和特征为研究对象的。随着科技的快速发展,科技哲学的传播也必然会出现一些问题,因此,只有在了解科技哲学的本质的基础上,分析科技哲学目前的发展和研究现状,正确认识科技哲学在传播过程中存在的问题,才能更好地促进科技哲学的传播和发展。     

影响移动通信企业顾客价值的因素分析

对于顾客价值的研究,以往都注重对定义和内涵的比较,或者是评价模型的建立。本文将研究的对象置于移动通信行业,采用了问卷调查和因子分析的方法,通过对移动通信企业顾客价值的影响因素分析,来为移动通信企业进行战略选择提供依据。