iPhone语音通话中G.729A算法的优化及实现

由于G.729A运算模块中开环基音搜索占据了比较大的运算量,在分析了它的算法结构之后,提出了4∶1的抽取方法,即对采样信号点及最佳延时搜索点进行4∶1的抽取。同时,在C代码的基础上去除了串行化模块中1 bit向Word16的数据转换,避免了程序中语音数据的类型转换。最后,将优化后的G.729A封装成静态库,加载到iPhone语音通话软件中进行测试。结果显示,提出的方法降低了开环基音搜索的复杂度,在语音质量稍微有所下降的基础上,提高了语音实时性。     

Mobile learning vs. traditional classroom lessons: a comparative study

Different methods can be used for learning, and they can be compared in several aspects, especially those related to learning outcomes. In this paper, we present a study in order to compare the learning effectiveness and satisfaction of children using an iPhone game for learning the water cycle vs. the traditional classroom lesson. The iPhone game includes multiple interaction forms and combined augmented reality (AR) mini‐games with non‐AR mini‐games. The traditional classroom lesson had the same learning content as the iPhone game. Thirty‐eight children participated in the study. The analyses showed that the children made significant learning gains about the water cycle, regardless of the method used. Even though the results showed that the iPhone method achieved higher knowledge results than the traditional classroom lesson, no statistically significant differences were found between the iPhone and the classroom lesson. When analysing the motivational outcomes, the results showed that the children found the iPhone game to be more satisfying than the classroom lessons. Since the iPhone game achieved similar learning results and a higher motivational effect than the classroom lesson, this suggests that games of this kind could be used as a tool in primary schools to reinforce students' lessons.     

Urban Interactive

Valentina Croci profiles the work of entertainment design office Area/Code which foregrounds urban locations in its games. As Croci explains the approach of this NewYork-based partnership, which delivers sat nav-inspired gaming to the mobile phone, demonstrates an inherent understanding of the importance of the physical in enhancing the imaginary. Copyright © 2010 John Wiley & Sons, Ltd.     

QR Panopticism: User Behavior Triangulation and Barcode-Scanning Applications

ABSTRACT

The increasingly ubiquitous two-dimensional barcodes designed by the Denso Wave company, known as the QR code, were originally intended to track millions of parts as they moved about on high-speed assembly lines. Since then, these increasingly ubiquitous black and white squares have been applied to an ever-broader range of nonindustrial uses. In order to make use of these codes, the vast majority of consumers use smart phone technologies in order to convert the codes into usable information. However, neither Apple’s iOS nor Google’s Android operating systems include a robust native capability to decode printed barcodes. As a result, users of these devices must download and install third-party applications that will do this work for them. Our research question is straightforward: are there privacy and security risks associated with this emerging QR app ecosystem? We installed and analyzed over twenty of the most popular QR code applications. Our findings suggest that a majority of the most popular QR code readers found in the Apple App and Google Play marketplaces are not passive systems, but instead capture and transmit additional data about the device back to the application developer. The paper then considers the privacy and security implications of the QR code app ecosystem.     

An empirical analysis of smartphone personalisation: measurement and user variability

The present report is an empirical analysis of smartphone personalisation. We collected data from two groups of users to measure how they adapt the content, interface and physical appearance of their devices. This user-driven personalisation is measured with a simple heuristic approach to quantify the behaviour. Using these scores, we explore how users differ from each other in how they personalise their smartphones with a focus on gender differences, usability and device usage in the wild. Among our findings are that not all users personalise their smartphones, females and males personalise their iPhones differently, and those who personalised their phones more tended to rate it as more usable. The users who personalised more also used their device for greater periods of time on a broader range of applications. For instance, individuals who adapted their iPhones to a greater degree also accessed the Web more often and spent more time browsing once it was accessed. We conclude with a discussion of possible factors underlying the large user diversity of smartphone personalisation found in this research.     

关于iPhone 4手机信号问题的探讨

iPhone 4为达到超薄机身和玻璃外壳的设计,将天线整合到不锈钢材质外围包边,用户只要同时握住他们就会出现信号衰减。在查阅了大量资料之后,导出iPhone 4的信号问题是由软件和硬件共同产生的。具体来有三个原因,现将详细分析三个原因,提出较为合理的改进方案,旨在阐述该产品的不足之处,解答消费者的疑惑,为iPhone 4保留市场占有率提供一点儿建议。     

基于NAND的iOS数据恢复研究

iPhone作为一种市场占有率较高的主流智能行动电话,在各行各业中应用广泛。因此,也衍生出针对iPhone上各种加密信息的提取与解密、已删除信息的恢复,以及多媒体信息的真实性鉴定等需求。目前,国内对于iOS数据恢复研究成果十分欠缺,这里提出了一种通过直接读取底层NAND存储,分析NAND本身的FTL读写特性所造成的数据冗余,以此来达到成功恢复已删除数据的目的,此方法可为iOS平台上的数据恢复人员提供一定的指导作用。     

iPastoral

Architectural theorist and educator Mark Morris parallels the 18th-century enthusiasm for the Claude glass, a black mirror that framed and filtered views into painterly landscapes, with the current infatuation for a similarly small shiny black device with a capacity for taking picturesque images.     

智能手机数据的提取与恢复

随着移动通信技术的发展,手机成为人们工作生活中必备的通讯工具,与此同时,手机犯罪也与日俱增,手机取证是打击这类犯罪的有效手段。以iPhone手机为例,介绍了数据恢复工具的安装,以及对智能手机的数据进行提取与恢复的方法。