Jacob Löfvenberg

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Thresholds for sensation of continuous sinusoidal skin displacements were determined in 7 different test points in the glabrous skin area of the right hand of 11 human subjects. While the subjects were tracking the threshold, the frequency of the sine wave was continuously varied between 0.8 Hz and 400 Hz. THe obtained threshold-frequency functions showed(More)
Unlicensed, or illegal, copying of data is a problem in many areas. Despite various efforts in copy protection and copyright enforcement (both legal and technical), the problem still exists, and with the growing use of digital means of storing and distributing data the problem seems to be getting worse. Storing a unique, invisible marking in each(More)
Unlicensed, or illegal, copying of data is a problem in many areas. Despite various efforts in copy protection and copyright enforcement (both legal and technical), the problem still exists, and with the growing use of digital means of storing and distributing data the problem seems to be getting worse. Storing a unique, invisible marking in each(More)
In this paper we present a simplified model of parallel, on-chip buses, motivated by the movement toward CMOS technologies where the ratio between interwire capacitance and wire-to-ground capacitance is very large. We also introduce a ternary bus state representation, suitable for the bus model. Using this representation we propose a coding scheme without(More)
Coding methods for fingerprinting digital information are considered, with the aim of deterring users from copyright violation. A general model for discrete fingerprinting is presented, along with a simple embedding method for text documents. Different types of attacks are discussed, including attacks from collud-ing pirates. Some preliminary results are(More)
Illegal copies of digital objects (images, texts, movies, music etc.) are easy to make. With the use of Internet more and more products are distributed in its digital form. To prevent illegal redistribution we propose to uniquely mark each distributed copy with a digital fingerprint. This fingerprint has to be part of the information to prevent it from(More)