Hewlett-Packard

About: Hewlett-Packard is a company organization based out in Palo Alto, California, United States. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 34663 authors who have published 59808 publications receiving 1467218 citations. The organization is also known as: Hewlett Packard & Hewlett-Packard Company.

Power transfer apparatus for concurrently transmitting data and power over data wires

Abstract: Electrical supply current, sufficient to power a wireless access point, is transmitted concurrently with a network data signal across a transmission line. A power and data coupler couples the network data signal and the power signal, received through a data input and a power input respectively, and transmits the coupled signal, to a distance of three meters or more, over the transmission line to a power and data decoupler. The power and data decoupler separates the power signal from the network data signal and supplies those signals to a power output port and a data output port, respectively, for use by a wireless access node. The power signal may be modulated at a low frequency relative to the frequency of the data signal, and the network data signal has a data transmission rate of one megabit/second or higher.

Privacy, Security and Trust Issues Arising from Cloud Computing

Abstract: Cloud computing is an emerging paradigm for large scale infrastructures. It has the advantage of reducing cost by sharing computing and storage resources, combined with an on-demand provisioning mechanism relying on a pay-per-use business model. These new features have a direct impact on the budgeting of IT budgeting but also affect traditional security, trust and privacy mechanisms. Many of these mechanisms are no longer adequate, but need to be rethought to fit this new paradigm. In this paper we assess how security, trust and privacy issues occur in the context of cloud computing and discuss ways in which they may be addressed.

Association rule hiding

Abstract: Large repositories of data contain sensitive information that must be protected against unauthorized access. The protection of the confidentiality of this information has been a long-term goal for the database security research community and for the government statistical agencies. Recent advances in data mining and machine learning algorithms have increased the disclosure risks that one may encounter when releasing data to outside parties. A key problem, and still not sufficiently investigated, is the need to balance the confidentiality of the disclosed data with the legitimate needs of the data users. Every disclosure limitation method affects, in some way, and modifies true data values and relationships. We investigate confidentiality issues of a broad category of rules, the association rules. In particular, we present three strategies and five algorithms for hiding a group of association rules, which is characterized as sensitive. One rule is characterized as sensitive if its disclosure risk is above a certain privacy threshold. Sometimes, sensitive rules should not be disclosed to the public since, among other things, they may be used for inferring sensitive data, or they may provide business competitors with an advantage. We also perform an evaluation study of the hiding algorithms in order to analyze their time complexity and the impact that they have in the original database.

City of bits: space, place and the infobahn

Abstract: O ne of the continuing challenges of the information revo lution of the past few decades is that the important "stuff" of the technology is beyond the capabilities of our human senses. We can't see the bits in our computers or the electrons that represent them. We can write our thoughts and translate those thoughts into software code, but we can only imagine the logic flows, branches, and data movements that occur as that code is converted to electrons and executed. We send all these electrons into networks, where the electrons that represent the code are chunked into packets, disassembled and assembled, causing our thoughts to visit places and follow routes that our physical bodies could never go. We call this imaginary world "virtual," as though the label makes it real. We create analogs to what our senses can deal with. We talk about files and architectures and highways, pages and webs, all of which we sort of understand in the real world, thus giving us Slippery handles on the virtual. The truth is scary: our physical bodies are irrelevant in the virtual world. William Mitchell, Dean of the School of Architecture and Planning at MIT, spends 225 pages trying to relate the two worlds, but early on he tells us that he knows better by showing us the famous New Yorker cartoon of two dogs in front of a personal computer saying, "On the Internet, nobody knows you're a dog"...or if you're tall or short, young or old, strong or sick...all of which are crucial in the physical world. In many ways, what Mitchell is doing in this book is important. Creating analogs from the unknown to the known helps us manage the acceptance of the new technology. Mitchell shows these comparisons explicitly in his section headings; e.g., "Schoolhouses/Virtual Campuses," "Galleries/Virtual Museums," "Tangible Goods/Intellectual Property." These analogs not only help us better understand and accept the novel and unknown, but the analogies help us apply the new in ways that far extend the capabilities of the old. So, in our virtual museum in one time and place, we are able to see paintings that physically exist in galleries tens of thousands of miles apart, without the burden of crowds or jet lag. The virtual campus can bring to the most remote schoolhouse the best lessons of the best teachers, regardless of where or when those lessons were physically articulated. But extending the old capabilities can be either a way station to or a side track away from the ultimate benefits of the virtual world. The technology to let go of our physical selves is ready, but our society is not. Our past, built on what our senses can tell us, is an anchor keeping us stuck in the harbor of known, preventing us from sailing into the sea of unknown. Looking at birds for thousands of years got us only Icarus. It was not poor ships that kept Vikings and Phoenicians close to shore; it was fear of the dragons on the maps where the known seas ended. Again, Mitchell knows this and hints about it a bit. For example, in his discussion of Bookstores/Bit Stores, he talks about the old world of the large urban newspaper: "When the Chicago Tribune Tower was constructed, it stood as the proudly visible center of a vast collection and distribution system and as an emblem of the power of the press. Every day the news flowed in and the printed papers flowed out to the surrounding metropolis. But on the infobahn, where every node is potentially both a publication and a consumption point, such centralized concentrations of activity will be supplanted by millions of dispersed fragments." Mitchell thus hints at hut doesn't mention the long-envisioned world of Xanadu described by Ted Nelson, arguably the father of hypertext, a real break with the linear flow of the printing press paradigm, possible only in cyberspace.

Separability of very noisy mixed states and implications for nmr quantum computing

Abstract: We give a constructive proof that all mixed states of N qubits in a sufficiently small neighborhood of the maximally mixed state are separable (unentangled). The construction provides an explicit representation of any such state as a mixture of product states. We give upper and lower bounds on the size of the neighborhood, which show that its extent decreases exponentially with the number of qubits. The bounds show that no entanglement appears in the physical states at any stage of present NMR experiments. Though this result raises questions about NMR quantum computation, further analysis would be necessary to assess the power of the general unitary transformations, which are indeed implemented in these experiments, in their action on separable states.