This paper presents the first complete design to apply compressive sampling theory to sensor data gathering for large-scale wireless sensor networks. The successful scheme developed in this research is expected to offer fresh frame of mind for research in both compressive sampling applications and large-scale wireless sensor networks. We consider the scenario in which a large number of sensor nodes are densely deployed and sensor readings are spatially correlated. The proposed compressive data gathering is able to reduce global scale communication cost without introducing intensive computation or complicated transmission control. The load balancing characteristic is capable of extending the lifetime of the entire sensor network as well as individual sensors. Furthermore, the proposed scheme can cope with abnormal sensor readings gracefully. We also carry out the analysis of the network capacity of the proposed compressive data gathering and validate the analysis through ns-2 simulations. More importantly, this novel compressive data gathering has been tested on real sensor data and the results show the efficiency and robustness of the proposed scheme.

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Compressive data gathering for large-scale wireless sensor networks

The disclosed methods and apparatus relate generally to the electronics media industry, such as cable television (CATV), home shopping services, on-line computer services and computer memory applications. These methods and apparatus allow a user to access and make use of electronic media input and output devices by reference to and/or utilization of standard printed matter, such as magazines, textbooks, or any other printed matter that can be correlated to electronic media.

Method and apparatus for accessing electronic data via a familiar printed medium

The present invention provides a method and apparatus for the production and labeling of objects in a manner suitable for the prevention and detection of counterfeiting. Thus, the system incorporates a variety of features that make unauthorized reproduction difficult. In addition, the present invention provides an efficient means for the production of labels and verification of authenticity, whereby a recording apparatus which includes a recording medium, having anisotrophic optical domains, along with a means for transferring a portion of the recording medium to a carrier, wherein a bulk portion of the recording medium has macroscopically detectable anisotrophic optical properties and the detecting apparatus thereon.

Authentication method and system

A method of performing digital asset management of media content. In this method, a watermark reader device reads a watermark embedded into media content. The watermark conveys watermark information, such as a content identifier and creator identifier. The reader forwards the watermark information to a router. The router then uses the watermark information to find a metadata database identifier. It then sends a request for metadata along with the watermark information to the metadata database identified by the metadata database identifier. The metadata database uses the watermark information to find related metadata for the media content and sends the related metadata to the reader device.

Digital asset management and linking media signals with related data using watermarks

The present invention provides methods and systems for authenticating identification documents (100). We also teach an identification document (100) including two or more digital watermarks (27, 60). The watermarks correspond with each other or with indicia carried by the identification document (100). The correspondence can be verified to determine authenticity. We also provide digital watermark detection methods and systems to identify the different watermarks (100) through embedded orientation components. We then focus watermark message-decoding efforts on areas identified as likely including watermark orientation components (27, 60). In one implementation we provide a watermark detection trigger to identify so-called legacy documents. The trigger may indicate the presence or expected absence of a digital watermark. In other implementations we provide a versatile document authenticator to toggle between watermarking and non-watermarking authentication processes depending on a detection trigger (100).

Identification document and related methods

The disclosure describes an authentication system and related methods for authenticating printed objects. The system uses an information-based metric along with one or more print quality metrics to provide accurate detection or classification of a counterfeit printed object. The print quality metric evaluates attributes of a subject image associated with the original printer, ink or paper to detect degradation of those operations due to copying operations like an image scanning and halftone printing subsequent to the original printing of the object. The information-based metric measures message symbol errors in an optically readable code, such as a digital watermark.

Authenticating printed objects using digital watermarks associated with multidimensional quality metrics

The disclosure describes methods for using digital watermarking to authenticate digital media signals, such as images, audio and video signals. It also describes techniques for using embedded watermarks to repair altered parts of a media signal when alteration is detected. Alteration is detected using hashes, digital watermarks, and a combination of hashes and digital watermarks.

Content authentication and recovery using digital watermarks

A watermark embedder transforms a media signal from its perceptual domain to frequency domain regions and embeds a hash of data from one frequency domain region into a watermark in another frequency domain region. Alternatively, it encodes instances of the same message into the frequency domain regions. To detect alteration of the media signal, a watermark decoder transforms a suspect signal into the frequency domain regions, extracts the watermark message from a first frequency domain region and compares it with a reference derived from another frequency domain region. The reference signal is either a hash computed from the other frequency domain region of the watermarked signal, or another instance of the same message embedded into the other frequency domain region. The decoder can be used to detect alteration of the signal, such as alteration that occurs with reproduction (printing, scanning, copying, D/A-A/D conversion, etc.), compression, cropping or swapping of media signal content, etc.

Digital authentication with digital and analog documents

The disclosure details a method of measuring the quality of service of broadcast media signals by analyzing digital watermarks embedded in the received broadcast signal. This method enables the quality of the broadcast video or audio signal to be measured without having the original version of the signal before broadcast transmission. Instead, the method analyzes the strength or quality of the embedded digital watermark to determine the quality of the received broadcast signal. The degradation of a watermark signal is used to measure quality of service of broadcast signals, such as audio and video.

Measuring quality of service of broadcast multimedia signals using digital watermark analyses

A method and apparatus are described for determining a threshold, including selecting a desired false result probability, and selecting a threshold value from a threshold table corresponding to the desired false result probability. Also described are a method and apparatus for determining a threshold corresponding to a desired false result probability, including calculating a false result probability, calculating a difference value between the calculated false result probability and the desired false result probability, comparing the difference value to a first predetermined value and comparing the difference value to a second predetermined value if a result of the first comparing act is positive.

Jun Tian

Papers

Authenticating printed objects using digital watermarks associated with multidimensional quality metrics

Content authentication and recovery using digital watermarks

Digital authentication with digital and analog documents

Measuring quality of service of broadcast multimedia signals using digital watermark analyses

Method and apparatus for setting a detection threshold given a desired false probability