An architectural framework for supporting heterogeneousinstruction-set architectures

An architectural framework that allows software applications and operating system code written for a given instruction set to migrate to different, higher performance architectures is described. The framework provides a hardware mechanism that enhances application performance while keeping the same program behavior from a user perspective. The framework is designed to accommodate program exceptions, self-modifying code, tracing, and debugging. Examples are given for IBM System/390 operating-system code and AIX utilities, showing the performance potential of the scheme using a very long instruction word (VLIW) machine as the high-performance target architecture     

A data-driven VLSI array for arbitrary algorithms

The design of specialized processing array architectures, capable of executing any given arbitrary algorithm, is proposed. An approach is adopted in which the algorithm is first represented in the form of a dataflow graph and then mapped onto the specialized processor array. The processors in this array execute the operations included in the corresponding nodes (or subsets of nodes) of the dataflow graph, while regular interconnections of these elements serve as edges of the graph. To speed up the execution, the proposed array allows the generation of computation fronts and their cancellation at a later time, depending on the arriving data operands; thus it is called a data-driven array. The structure of the basic cell and its programming are examined. Some design details are presented for two selected blocks, the instruction memory and the flag array. A scheme for mapping a dataflow graph (program) onto a hexagonally connected array is described and analyzed. Two distinct performance measures-mapping efficiency and array utilization-and some performance results are discussed     

A 1-GHz logic circuit family with sense amplifiers

This paper describes a newly developed logic circuit family based on dual-rail bit lines and sense amplifiers that is used extensively in a 1.0-GHz, single-issue, 64-bit PowerPC integer processor, gigahertz unit test site (guTS). The family consists of an incrementor, a count-leading-zero, a rotator, and a read-only memory. Each macro consists of a leaf-cell array, dual-rail bit lines, a row of sense amplifiers, a control block, and peripheral circuits. A common read-out scheme sensing the differential voltage of dual-rail bit lines is used. The hardware was fabricated in a 0.25-μm drawn channel length, six-metal-layer (Al) CMOS technology (1.8-V nominal VDD). Wafer testing was performed using a probe card. The macros were tested cycle by cycle by scanning the input data to the read/write address latches and data latches, and scanning the result out from the output receiving latches. Functional testing was performed on guTS macros at frequencies up to 1.0 GHz at 25°C with nominal VDD (1.1 GHz for the ROM)     

Relaxation Properties and Chemical Nature of Polymer Surface Layers as Related to the Strength of Adhesive Joints with Metals

A new approach based on the theory of elasticity is proposed to study relaxation properties of adhesive transition layers. It involves experimental evaluation of the rate dependence of the fracture energy of the bulk polymer and its adhesive joint.

The investigation of the interaction of a polymer surface layer with electroplated copper by XPS using the effect of differential charging (the latter produced by potential shift of the sample by 10V), makes it possible to identify the functional groups of adhesive brought into contact with substrate surface. For ABS copolymers a bond of -O … Cu type was formed.

The mechanism of adhesive contact formation and factors affecting the strength of adhesive joints could be understood better by determining the properties of surface and transition layers.     

Virtual-reality heritage presentation at Ename

Virtual reality (VR) and multimedia are central components of the heritage presentation programme at Ename, Belgium. These techniques are designed to help the visitor understand and experience the past as revealed through archaeological and historical research. The programme uses different VR approaches to bring to life archaeological remains, standing monuments and elements of the historical landscape for visitors. We named the overall project “Ename 974” to commemorate the foundation date of the first mediaeval settlement. Its major aim is to communicate new insights about archaeology, history and conservation to the general public, paying great attention to scholarly accuracy and by means of multimedia technologies. Among the most important of these technologies are on-site virtual reconstructions, museum multimedia and educational projects. Since 1998, the Ename Centre for Public Archaeology and Heritage Presentation has served as an international extension of the Ename 974 project. Its goal is to develop new technologies and new standards for heritage presentation. It also coordinates heritage presentation projects and educational programmes for partner sites around the world     

Research without external funding in North American psychiatry

OBJECTIVE: The authors investigated the extent and characteristics of published psychiatric research from U.S. and Canadian medical schools that was carried out without external funding. METHOD: They reviewed reports of unfunded research in 14 psychiatric journals, tabulating methodological factors and topics of study. They surveyed first authors about their academic duties and resources used in the studies. RESULTS: Unfunded studies represented 26% of research reports, were usually prospective, most commonly dealt with phenomenology/epidemiology or psychopharmacology, used low levels of technology, and were accomplished on a modest budget of time and money. CONCLUSIONS: Unfunded studies make a substantial and economically efficient contribution to psychiatric research. Future investigations should detail the institutional conditions necessary to sustain this type of research productivity.