IBM

About: IBM is a company organization based out in Armonk, New York, United States. It is known for research contribution in the topics: Layer (electronics) & Signal. The organization has 134567 authors who have published 253905 publications receiving 7458795 citations. The organization is also known as: International Business Machines Corporation & Big Blue.

CORBA fundamentals and programming

Abstract: Since it supports a wide range of approaches to system integration, CORBA is complex and often prone to subjective interpretation. An understanding of the trade-offs involved in various approaches is crucial. Fostering this kind of understanding is the inspiration for the Object Management Architecture (OMA). After a review of OMA, CORBA, and Common Object Services Specification (COSS), this book discusses object-oriented analysis and design methods and compares available object request brokers. It provides a fully-worked example with a single object implementation. Other examples address cascading object calls, inheritance, and the use of multiple object services. On the disk: Source code in C, C++ Source code in Smalltalk Interface Definition Language Interfaces.

Unextendible product bases and bound entanglement

Abstract: An unextendible product basis( UPB) for a multipartite quantum system is an incomplete orthogonal product basis whose complementary subspace contains no product state. We give examples of UPBs, and show that the uniform mixed state over the subspace complementary to any UPB is a bound entangled state. We exhibit a tripartite 2 3 2 3 2 UPB whose complementary mixed state has tripartite entanglement but no bipartite entanglement, i.e., all three corresponding 2 3 4 bipartite mixed states are unentangled. We show that members of a UPB are not perfectly distinguishable by local positive operator valued measurements and classical communication. [S0031-9007(99)09360-6]

Method and system for controlling access share storage devices in a network environment by configuring host-to-volume mapping data structures in the controller memory for granting and denying access to the devices

Abstract: The invention provides structure and method for controlling access to a shared storage device, such as a disk drive storage array, in computer systems and networks having a plurality of host computers. A method for controlling access to a hardware device in a computer system having a plurality of computers and at least one hardware device connected to the plurality of computers. The method includes the steps of associating a locally unique identifier with each the plurality of computers, defining a data structure in a memory identifying which particular ones of the computers based on the locally unique identifier may be granted access to the device; and querying the data structure to determine if a requesting one of the computers should be granted access to the hardware device. In one embodiment, the procedure for defining the data structure in memory includes defining a host computer ID map data structure in the memory; defining a port mapping table data structure comprising a plurality of port mapping table entries in the memory; defining a host identifier list data structure in the memory; defining a volume permission table data structure in the memory; and defining a volume number table data structure in the memory. In one particular embodiment, the memory is a memory of a memory controller controlling the hardware device, and the hardware device is a logical volume of a storage subsystem. The invention also provides an inventive controller structure, and a computer program product implementing the inventive method.

Beyond the conventional transistor

Abstract: This paper focuses on approaches to continuing CMOS scaling by introducing new device structures and new materials. Starting from an analysis of the sources of improvements in device performance, we present technology options for achieving these performance enhancements. These options include high-dielectric-constant (high-k) gate dielectric, metal gate electrode, double-gate FET, and strained-silicon FET. Nanotechnology is examined in the context of continuing the progress in electronic systems enabled by silicon microelectronics technology. The carbon nanotube field-effect transistor is examined as an example of the evaluation process required to identify suitable nanotechnologies for such purposes.

Scanning interferometric apertureless microscopy: optical imaging at 10 angstrom resolution.

Abstract: Interferometric near-field optical microscopy achieving a resolution of 10 angstroms is demonstrated. The scattered electric field variation caused by a vibrating probe tip in close proximity to a sample surface is measured by encoding it as a modulation in the optical phase of one arm of an interferometer. Unlike in regular near-field optical microscopes, where the contrast results from a weak source (or aperture) dipole interacting with the polarizability of the sample, the present form of imaging relies on a fundamentally different contrast mechanism: sensing the dipole-dipole coupling of two externally driven dipoles (the tip and sample dipoles) as their spacing is modulated.