Increasing the audio watermark data rate in the construction of ubiquitous acoustic spaces

We propose “Ubiquitous Acoustic Spaces,” in which each sound source can emit some address information with audio signals and allow automatic access to its related cyber space, using handheld devices such as cell phones. In order to realize this concept, we have considered three types of extraction methods: acoustic modulation, audio fingerprints, and audio watermarking. We have proposed a novel audio watermarking technique, which allows contactless asynchronous detection of embedded audio watermarks through speaker and microphone devices. However, its embedding data rate was around 10 bps, which was not sufficient for embedding generally used URL address texts. Therefore, we have extended the embedding frequency range and proposed a duplicated embedding algorithm, which uses both the previously proposed frequency division method and the temporal division method together. By these improvements, the possible embedding data rate could be extended to 61.5 bps, and we could extract watermarks through public telephone networks, even from a cell phone sound source. In this paper, we describe our improved watermark embedding and extracting algorithms, and present experimental results on watermark extraction precision under several audio signal capturing conditions. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(1): 42–51, 2008; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20758     

Mobile communications - an overview

This article focuses on voice communications using mobile (cell) phones over mobile/cellular networks. The advances in processors, memory, signal processing, communication technologies, and several related techniques, personal mobile communications has witnessed tremendous growth. A typical mobile communication network consists of: mobile devices, BS, mobile switching centers, gateway mobile switching center. Cell phones communicate wirelessly with BSs. Base stations communicate with MSCs on fiber-optic cables or microwave links. Some of the extensions are also made in the cell phone, MMS, JPEG format, MPEG format, graphics, and animation.     

Alien Revolt (2005-2007): A Case Study of the First Location-Based Mobile Game in Brazil

Location-aware technology and Internet connectivity embedded in mobile phones allow users to navigate physical spaces and be connected to other users, bringing many activities formerly performed "online" to physical hybrid spaces. Among such activities are location-based mobile games (LBMGs), which use urban spaces as the game scenario. This article is a case study of Alien Revolt (2005-2007), the first Brazilian LBMG, released in 2005 by the company Mind Corporation and the operator Oi in Rio de Janeiro. The game uses Java-enabled cell phones equipped with location awareness to transform the city into a battlefield. Following much of the Swedish game Botfighters' (2001-2005) idea, the first LBMG, Alien Revolt's goal involves virtually shooting other players within a specific radius in the city space. Alien Revolt exemplifies how cell phones strengthen users' connections to physical space, because they are used as collective communication devices, rather than personal private technologies. Moreover, when used for location-based activities, the cell phone plays the role of a location aware technology, rather than a mobile telephone used for two-way voice communication.     

Solutions to electromagnetic interference problems between cochlear implants and GSM phones.

For persons using cochlear implants, electromagnetic compatibility (EMC) problems may sometimes be an obstacle to using digital cellular telephones. This study aimed at exploring the benefit of three new assistive listening device prototypes that eliminate or diminish EMC problems. Ten experienced cochlear implant users listened in quiet to running speech samples and a sentence test on a landline phone, a digital cellular phone with and without three prototypes. The subjects' performance was assessed using a sentence test, a subjective visual analog scale, and by ranking the best and the poorest listening condition. Compared to the other test conditions, listening to a digital cellular phone alone revealed, on average, the poorest sentence recognition scores (29%) and the poorest results in four different subjective judgments (the amount of disturbances, the clarity of the message, the quality of the sound, overall judgment) with all three implant systems tested. The prototypes generally helped the implantees to recognize speech better on the cellular telephone (by 10-21 percent units, on average). Use of assistive listening devices and further development of EMC of both cochlear implant systems and digital cellular phones needs to take place to enable smooth use of digital cellular phones for all implantees.     

A CTI System to Support the Seamless Workplace and Its Implementation

This paper proposes a CTI client/server coordination system exclusively for use with a smart phone. The system makes use of a CTI client, performing combined functions of a SIP phone and a Web browser. The proposed CTI client/server coordination system comprises SIP servers and Web servers, both of which are installed in enterprises, and CTI clients that run on smart phones in a mobile environment. Furthermore, the CTI clients perform the function of SIP phone by communicating with SIP servers. In addition, CTI clients can display telephone directories and logging of phone calls stored in Web servers. They can display screens of ordinary Web browsers. Here, one might switch between a SIP phone function and a Web communication screen with merely a single touch of the tab key. Consequently, smart phones in the mobile environment make it possible to conduct telephone meetings while browsing with a Web screen.     

Space-Based Passing Time Estimation on a Freeway Using Cell Phones as Traffic Probes

This paper examines the usability of mobile cellular networks to obtain traffic information on a freeway. The question of whether a mobile station (cell phone) can play an acceptable role as a probe for collecting traffic information on a freeway is examined. A space-based approach, wherein the probe vehicles transmit information to roadside devices as they pass through reference points, is exploited rather than a time-based approach, wherein the probe vehicles report information for every specific instant of time. The latter has been of concern to most researchers interested in the use of a mobile cellular network for collecting traffic data. First, a simple analytical model is introduced to address the usability of cell phones as traffic probes and to pinpoint which factors affect the qualification of probe phones when the space-based approach is adopted. Second, simulation experiments are also employed to deal with more realistic traffic conditions as supplementary tools for the analytical model. Finally, the actual traffic data on a freeway was considered to validate the above two hypothesized traffic conditions. The findings show that there are three main factors that affect the qualification of cell phones as a traffic probe: 1) the speed profile of the probe phone in cell coverage; 2) the variability of handoff location where the probe phone switches its jurisdictional cell; and 3) the locational relationship between a reference point and a speed jump (or drop) point in cell coverage.      

基于DCT系数的量化音频水印

近年许多水印算法被提出并应用到图像和视频中去，相较于人类视觉系统，听觉系统的敏感性使得音频水印的实现要难于图像视频水印。为了提高音频水印的不可见性，提出一种离散余弦变换（DCT）的量化音频水印算法，先是基于能量将原始音频分为两部分,对能量较大的部分进行分块离散余弦变换，然后对变换之后的中频系数均值采用量化索引调制（QIM）嵌入Arnold置乱后的二进制水印图片，保证水印的嵌入对原始音频的影响在听觉觉察范围之内。实验结果表明,算法具有很好的不可见性，并且对MP3压缩和噪声具有较好的鲁棒性。     

Audio watermarking time-frequency characteristics

In this paper, a novel audio watermarking scheme based on spread spectrum techniques is proposed. This technique embeds a digital watermark within an audio signal using the instantaneous mean frequency (IMF) of the signal. Audio watermarking offers a solution to data piracy and helps to protect the rights of the artists and copyright holders. The proposed content-based algorithm aims to satisfy and maximize both imperceptibility and robustness of the watermark. In addition, the technique uses the short-time Fourier transform of the original audio signal to estimate a weighted IMF of the signal. Based on the masking properties of the psychoacoustic model, the required sound pressure level of the watermark is calculated. Modulation is then performed to produce a signal-dependent watermark that is imperceptible. The proposed method allows 25 bits to be embedded and recovered within a 5 second sample of an audio signal. Experimental results have shown that the scheme is robust to common signal processing attacks including filtering, MP3 compression, additive noise and resampling with a bit error rate in the range of 013%.     

基于奇偶量化的图像水印嵌入与检测方法

针对数字图像水印在嵌入和提取过程中要求载体图像和水印信息都具有完整性的基本特征,提出了基于奇偶量化的自适应水印嵌入与检测方法.该方法将水印信息的二值图像进行Arnold置乱,嵌入到载体图像DCT的中频系数中,利用Watson视觉模型和JPEG量化表共同自适应地调节量化步长,由于采用奇偶量化,水印提取方法简单.实验结果表...     

基于J2ME/Mobile SVG开发平台在移动GIS中应用

本文介绍一种基于Mobile SVG的移动GIS的应用.首先分析Mobile SVG 在移动设备中的优势,继而着重阐述SVG Tiny在Mobile GIS设计中的设计思想.该技术利用J2ME实现手机上网功能,将互联网与地图服务器进行交互所得到的GIS数据在客户端进行解析,在终端屏幕上实时显示,由手机键盘实现便捷的地图浏览功能.该方法解决了地图在放大或缩小时会产生模糊失真的现象,并且数据流量较小,在以后的无线传输中有着广阔的应用前景.     

一种远程网络收费管理系统的设计与实现

在电信部门，如何进行电话、手机和BP机实时收费是一项重要的任务，本文主要介绍一种基于远程网络的管理系统，适应于电信部门进行电话、手机和BP机的实时收费。     

基于改进的SSD模型手机违规使用目标检测

针对某些对手机使用有特殊规定的场所时常面临难以准确、高效地识别手机违规使用的问题,提出了一种基于改进的SSD模型来检测手机的违规使用。利用SSD模型获取初次目标位置及区域分类,并利用改进的DenseNet模型对初次目标框进行判定,从而获得精确的手机检测边界框。为改进数据预处理流程,采用了数据扩增与图像质量改善相结合的策略。在自建的手机检测数据集上的实验结果验证了这些改进策略的有效性,改进的SSD模型定位精度可达91.1%,识别精度高达98%,相比原有SSD模型提升了35%。改进的SSD模型同时具有识别精度高和定位精度高的特点,可为智能识别违规使用手机的行为提供理论依据和技术支持。     

一种基于DCT量化的视频水印算法

图像水印技术已经得到了一定的发展,但数字视频水印的研究仍是一个难点。为了更好地保护视频数据的版权,提出了一种新的视频水印算法。对图像帧的亮度分量其进行分块,每块进行离散余弦变换,把水印数据通过正负量化嵌入到各分块的低频系数中去。为增强算法的安全性,将原始水印图像和随机二值图像作为细胞神经网络（CNN）的输入,输出的图像再被用来进行进一步嵌入操作。载体视频中的部分图像帧被用来进行多次水印嵌入。实验结果表明该方法具有较好的鲁棒性,而且算法简单,便于视频实时处理。     

Siliconization of 60 GHz

Silicon-based RF and microwave technology has had a dramatic impact on the world of wireless technology. We can now access voice/data and entertainment in virtually every corner of the globe--with everything from short range Bluetooth and WiFi networks to cellular and satellite networks--to meet different range and throughput requirements. A laptop computer without wireless capability is unthinkable today, whereas, ten years ago, these technologies were in their infancy.What do the next ten years hold? What gaps in wireless technology exist even today? Perhaps the most obvious missing link is between the various devices that we carry with us, such as cellular phones or personal digital assistants (or smart phones if you prefer), digital cameras, music and video players (such as the ubiquitous iPod), laptops, and peripherals such as external hard drives and monitors. The case of the mobile smart phone is particularly important since the existing wireless connectivity is either too slow and power hungry (Bluetooth) or designed and optimized for longer ranges (WiFi). What is missing is a wireless universal connectivity that can support high data rates demanded by large data rate multimedia applications. Wireless technology has been conspicuously absent from MP3 music players (such as Apple's iPod), which are ideal candidates for downloading music and video. While ultrawideband (UWB) technology using the 3--10 GHz band promised to fulfill these needs, it fell short in many ways, and, today, most of the start-up companies pursuing UWB have folded.     

A phone-assistive device based on Bluetooth technology for cochlear implant users

Hearing-impaired people, and particularly hearing-aid and cochlear-implant users, often have difficulty communicating over the telephone. The intelligibility of telephone speech is considerably lower than the intelligibility of face-to-face speech. This is partly because of lack of visual cues, limited telephone bandwidth, and background noise. In addition, cellphones may cause interference with the hearing aid or cochlear implant. To address these problems that hearing-impaired people experience with telephones, this paper proposes a wireless phone adapter that can be used to route the audio signal directly to the hearing aid or cochlear implant processor. This adapter is based on Bluetooth technology. The favorable features of this new wireless technology make the adapter superior to traditional assistive listening devices. A hardware prototype was built and software programs were written to implement the headset profile in the Bluetooth specification. Three cochlear implant users were tested with the proposed phone-adapter and reported good speech quality.     

The future of wireless charging [Microwave Surfing]

Ah, the freedom of walking around with a sleek ultraportable computer, surfing the Web while also chatting with a friend on a mobile phone, all through invisible wireless networks! Unfortunately, sooner or later, the computer and phone batteries run out of juice and one is forced to search for their power adapters and tether them to a power strip. If only we could charge these devices wirelessly!     

基于闲置手机锂电池的多功能移动电源

手机更新换代的速度不断加快,由于不同手机锂电池规格迥异,导致更换手机后大量仍有使用价值的手机锂电池被闲置下来,造成巨大的资源浪费,或遭填埋而造成严重的环境污染。根据手机锂电池自身的充放电特点,提出一种多功能移动电源的设计方案。该多功能移动电源以手机锂电池作为电芯,以一个5 V Micro USB端口作为充电输入端,通过两个USB端口对外输出3.7、5 V两种电压,以满足不同电子设备的需求。由于实物模型制造成本低廉且实用性强,该方案具有较高的应用推广价值。     

拍照手机在低照度时成像分辨率的测试方法研究

分析了手机拍摄静止图像的影响因素,阐述了利用ISO 12233分辨率图表测试手机低照度成像分辨率的方法。对市场上常见的两款手机进行了测试,分别用显示图像评估法和软件测试空间频率响应法给出了计算公式、检测数据及结果,比较了两种数据分析方式的优缺点并给出结论。     

Mobile phone location determination and its impact on intelligenttransportation systems

Research and development on the technologies of locating the mobile (wireless) phone caller have been rapidly gaining momentum around the world. Once these technologies are mature enough to be deployed, they will have significant impact on automotive telematics and modern public transit systems. In this paper, we discuss why locating mobile phones becomes a hot topic among telecommunications giants, what technologies are being studied and standardized, when we are going to see the actual deployment, and what services they may provide? We then consider its potential impact on future intelligent transportation systems, including telematics and public transit systems. Many of us have already recognized how important a role the communications systems play in modern transportation. In the near future, if every mobile phone is able to determine its location, advances in our current transportation systems become inevitable     

离散小波变换和混沌结合的数字图像水印算法

提出了一种基于离散小波变换和混沌理论的数字图像水印算法.在水印嵌入过程中,首先对原始图像进行离散小波变换,提取其低频部分作为嵌入区域;然后利用混沌系统产生的混沌序列对水印进行加密,再将加密后的水印进行小波变换并提取其低频部分;最后将加密水印的低频部分嵌入到原始图像的低频部分中.水印提取过程需要原始载体图像,是一种明检测.通过水印相关系数NC和峰值信噪比PSNR评价水印算法性能.实验结果表明,提出的算法可以抵抗JPEG压缩、噪声、滤波等攻击,图像水印效果很好.