Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

Learn the basic properties and designs of modern VLSI devices, as well as the factors affecting performance, with this thoroughly updated second edition. The first edition has been widely adopted as a standard textbook in microelectronics in many major US universities and worldwide. The internationally-renowned authors highlight the intricate interdependencies and subtle tradeoffs between various practically important device parameters, and also provide an in-depth discussion of device scaling and scaling limits of CMOS and bipolar devices. Equations and parameters provided are checked continuously against the reality of silicon data, making the book equally useful in practical transistor design and in the classroom. Every chapter has been updated to include the latest developments, such as MOSFET scale length theory, high-field transport model, and SiGe-base bipolar devices.

/pdf/fundamentals-of-modern-vlsi-devices-471xd7l9pf.pdf

Fundamentals of Modern VLSI Devices

A prevalent and pervasive view of designing is that it can be modeled using variables and decisions made about what values should be taken by these variables. The activity of designing is carried out with the expectation that the designed artifact will operate in the natural world and the social world. These worlds impose constraints on the variables and their values; so, design could be described as a goal-oriented, constrained, decision- making activity. However, design distinguish- es itself from other similarly described activities not only by its domain but also by additional necessary features. Designing involves exploration, exploring what variables might be appropriate. The process of explo- ration involves both goal variables and deci- sion variables. In addition, designing involves learning: Part of the exploration activity is learning about emerging features as a design proceeds. Finally, design activity occurs within two contexts: the context within which the designer operates and the context produced by the developing design itself. The designer’s perception of what the context is affects the implication of the context on the design. The context shifts as the designer’s perceptions change. Design activity can be now characterized as a goal-oriented, con- strained, decision-making, exploration, and learning activity that operates within a con- text that depends on the designer’s percep- tion of the context.

Design Prototypes: A Knowledge Representation Schema for Design

Creativity: Flow and the Psychology of Discovery and Invention

Cognitive engineering

Good electrical performance of Silicon enables high harvested power density allowing Silicon to compete with conventional thermoelectric materials such as Bi 2 Te 3 or Sb 2 Te 3 . High value of thermal conductivity eliminating the use of Silicon in thermoelectricity is no longer an unbeatable drawback since the possibility of reduction has been established and confirmed. Thermal conductivity reduction by a factor 3 over bulk value is reported in 70nm thick Silicon. The Silicon thermal conductivity can be reduced even 100× over bulk when using dedicated patterning which can block the propagation of phonons responsible for heat transport [3]. This reduction will have significant influence in launching industrialization of CMOS compatible thermogenerators.

Fabrication of integrated micrometer platform for thermoelectric measurements

A fast numerical resolution of the Poisson and current continuity equations is used to model non-quasi-static effects in MOS circuits under fast switching conditions. The resulting model is continuous over all regimes of operation and accounts for the non-instantaneous redistribution of the channel charge. The capabilities of this modelling approach are exemplified through the simulation of current mode analog circuits.

Efficient non-quasi-static MOSFETs model for circuit simulation

Ytterbium silicide provides a low Schottky barrier height to electron on n-type silicon. This property makes this material very attractive for the realization of Source/Drain contacts for n-type MOSFETs. In this communication, the study of structural and electrical properties of YbSi2-x fabricated at different temperature in Ultra-High Vacuum condition without any protective layers is presented. N-type SB-MOSFETs with ytterbium silicide based S/D contacts were fabricated at optimal silicidation temperatures on SOI substrate with an ultra thin body.

UHV Fabrication of the Ytterbium Silicide as Potential low Schottky Barrier S/D Contact Material for n-type MOSFET

abstract Interactive systems are no longer expected to be used in confined and predefined places. By increasingly taking advantage of the physical environment, interactive systems are becoming mixed, that is, merging physical and digital worlds. Moreover, they support user's mobility and thus can be referred to as " mobile mixed systems. " To overcome technology-driven development processes and to take into account their physical nature and mobile dimensions, specific design approaches are required. From this perspective, we present the interweaving of an existing design model (ASUR) for mixed systems, and a 3-D environment (SIMBA) for simulating modelled mobile mixed system. The aims are to support the investigation of mobile mixed system design through the dedicated modelling approach, and to better understand the limit of the modelled solutions through their simulation. This constitutes a first step toward an iterative method of design for mobile mixed systems, based on " midfidelity " prototyping.

Modelling and Simulation of Mobile Mixed Systems

While ubiquitous data analytics is a promising approach, analyzing spreadsheets data on tablets is a tedious task due to the limited display size and touch vocabulary. In this paper, we present the design and evaluation of novel interaction techniques relying on the combination of a tablet, holding the data, and a smartphone, used as a mediator between the user and the tablet. To this end, we propose to use stacking gestures, i.e. laying one edge of a smartphone on the tablet screen. Stacking is a cheap, easy to implement and effective way of employing always-available smartphones to improve data analysis on tablets, by augmenting the input vocabulary and extending the display surface. We first explore stacking gestures to delimitate the possible interaction vocabulary and present the manufacturing of a conductive smartphone case. Then, we propose novel stacking-based techniques to perform spreadsheet data analysis, i.e. pivot table creation and manipulation. We evaluate our stacking techniques against touch interaction as provided by current mobile spreadsheet apps. Our studies reveal that some of our interaction techniques perform 30% faster than touch for creating pivot tables.

Emmanuel Dubois

Papers

Fabrication of integrated micrometer platform for thermoelectric measurements

Efficient non-quasi-static MOSFETs model for circuit simulation

UHV Fabrication of the Ytterbium Silicide as Potential low Schottky Barrier S/D Contact Material for n-type MOSFET

Modelling and Simulation of Mobile Mixed Systems

Combining Tablets with Smartphones for Data Analytics