U.S. online shopping: Facts,fiction, hopes and dreams

Much online shopping research has been viewed from the seller׳s side, i.e., volume, timing and the like. This paper looks at online shopping/buying from the buyer׳s view. Based on 285,000+ individual responses from an online U.S. panel, the questionnaires, gathered between 2006 and 2013, form the analytical base. Findings include an increase in online shopping volume among a declining customer base. Consumer reported details such as leading online retailers (Amazon.com), online product preferences, comparisons of online and fixed location research and buying scenarios, buying influences and the like are discussed. Managerial implications and suggestions for future research are included.     

网络购物中的危机

本文对现今社会上的网络购物中所碰到的危机开始讲述,从而进一步深入讨论了在科技发展的今天,网络犯罪也越来越防不胜防,以致于引发我们今后必须要改善的一些方向。     

高炮随动系统自动测试中正弦机发送频率的确定

在某型高炮随动系统测试中,正弦机的发送频率直接影响着输出信号的平滑度,从而会影响测试的精度。为了避免在正弦机运行过程中,计算耗用过多机时,在正弦机发送之前,先计算出每个位置信号、前馈信号的数值,存放于内存中。本文根据该正弦机信号的特点,分析了几种正弦机角位置信号发送频率方式的优缺点,确定了正弦机发送频率的方式。     

Causality effects in return volatility measures with random times

We provide a structural approach to identify instantaneous causality effects between durations and stock price volatility. So far, in the literature, instantaneous causality effects have either been excluded or cannot be identified separately from Granger type causality effects. By giving explicit moment conditions for observed returns over (random) duration intervals, we are able to identify an instantaneous causality effect. The documented causality effect has significant impact on inference for tick-by-tick data. We find that instantaneous volatility forecasts for, e.g., IBM stock returns must be decreased by as much as 40% when not having seen the next quote change before its (conditionally) median time. Also, instantaneous volatilities are found to be much higher than indicated by standard volatility assessment procedures using tick-by-tick data. For IBM, a naive assessment of spot volatility based on observed returns between quote changes would only account for 60% of the actual volatility. For less liquidly traded stocks at NYSE this effect is even stronger.     

我国零售业电子商务发展探讨

当前,我国零售业电子商务发展存在的问题,主要体现在信息不对称影响消费者决策,交易双方的信用难以确保,支付安全问题令人担忧,物流体系滞后制约零售业电子商务发展等方面.政府应从完善信用体系,保障支付安全,加强物流系统建设,重视人才培养等方面入手,切实解决零售业电子商务在发展过程中存在的问题,从而实现我国零售业电子商务的新发展.     

政府主导,创建知名旅游购物市场品牌

繁荣的旅游购物业对地方旅游业和社会经济发展具有非常重要的意义。创建知名旅游购物市场品牌是充分发展旅游购物业的先决条件 ,这其中政府主导将起到非常关键的作用     

综合商场的经营与管理

经营与管理是综合商场经营的重要组成环节,只有做好经营与管理,进行成本控制,提高商誉,拓展经营范围,才能提高企业综合效益,求得全方位的社会信誉,获得更为广阔的商场生存和发展空间。     

利用矢量网络分析仪测量时延特性的方法

解释了无线射频系统时延指标测量的意义及重要性,介绍了使用矢量网络分析仪进行时延指标测量的基本原理,归纳了网络分析仪进行线性器件、变频器件时延测量的测量方法,重点分析了变频器件时延测量的三种方法的原理、步骤和准确度.     

预应力混凝土梁桥自振特性分析

建立双折线预应力钢筋混凝土等直梁的强迫振动的运动微分方程,分析了梁在预应力钢筋作用下的横向振动问题,将运动微分方程解耦,得到梁在预应力作用下自振频率的解析解,分析了梁的自振频率与预应力和偏心距的关系,通过实例计算,得到了梁在不同预应力时梁桥的自振频率曲线。     

新型波导-微带对脊鳍线过渡设计

介绍了一种新型的宽带波导-微带对脊鳍线过渡设计。它利用对脊鳍线自身结构的调整,就可以对频带内谐振频率产生抑制作用,不需外加任何谐振抑制结构或金属孤岛,减少了设计和制造的复杂性。这种紧凑的过渡模型不仅结构简单、尺寸短小,而且可以在宽频带范围内实现较低的插入损耗和回波损耗,方便工程上的应用。对实验样品的测试表明,在Ka全频段内其插入损耗小于0.8 dB。