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

Depuis quelques annees les interfaces tangibles impliquant des interactions realisees via un objet (ou plusieurs) prennent de plus en plus d’importance dans les recherches en interaction homme-machine. L’objet tangible represente un sujet ou une action ; l’objet agit sur le systeme, telle une action sur une interface « classique ». L’interaction sur table, c’est-a-dire sur un meuble present dans la vie courante et utilise a diverses fins (bureau, table a manger, table de salon, table bar, etc.), ouvre un champ nouveau de recherche et de developpement. La mise en exergue, issue de l’etat de l’art, des definitions, modeles et problematiques, permet d’abord d’apprehender le couple (table, objet tangible) au sein d’un systeme interactif. Puis, nous proposons un cadre qui permet de positionner des applications mettant en oeuvre le couple (table, objet tangible). Le cadre est decrit de maniere a etre utilise pour positionner des applications independamment du domaine.

https://hal.archives-ouvertes.fr/hal-01386653/document

Interaction Tangible sur Table, définitions et modèles

Depuis plusieurs annees, les interfaces tangibles impliquant des interactions realisees via un ou plusieurs objets prennent une importance grandissante en interaction homme-machine. Ce domaine est en extension grâce au developpement d'objets exploitant des technologies sans contact (NFC, RFID, etc.). L'objet tangible represente un sujet ou une action ; cet objet agit sur le systeme, telle une action sur une interface « classique ». L'interaction sur table, c'est-a-dire sur un meuble present dans la vie courante et utilise a diverses fins (bureau, table a manger, table de salon, table bar, etc.), ouvre un champ nouveau de recherche et de developpement. Nous proposons d'illustrer un cadre propose dans un article conjoint, en positionnant des applications mettant en oeuvre le couple . Plusieurs applications, visant a supporter chacune une tâche metier complexe, sont decrites a la fois d'un point de vue technologique et d'un point de vue applicatif. Ces applications montrent les apports de l'association a l'interaction et sont caracterisees selon les dimensions du cadre de conception presente dans un article conjoint, montrant ainsi la genericite et le pouvoir descriptif du cadre propose.

https://hal.archives-ouvertes.fr/hal-01578894/document

Interaction Tangible sur Table, un cadre fédérateur illustré

Users of Ubiquitous Multimedia Communications Environments (UMCE), such as media spaces, have to manage a trade-off between gaining some awareness of colleagues’ ongoing activities and the risk posed to their own personal privacy by being ‘on permanent display’. UMCEs involve pervasive, continuous and heterogeneous connections between people and spaces. In order to learn more about the mechanisms underlying this trade-off, we studied a UMCE in the form of a minimal media space over a period of three months. We interpreted our results with reference to social identity theory, which casts self-identity as a set of affiliations and externally visible association with them. UMCE users themselves would define, configure and occupy places, or locales, within their spaces as a way of achieving a reliable and low-cognitive-effort management of their self-presentation. It may be that effective interpersonal and inter-group connections of this kind require attention to intra-space heterogeneity as well as heterogeneity in inter-space and technological terms. In this way, it would be possible to avoid the attentional demands of adjusting visibility through manipulations of sensor position or continually fiddling with filters. Instead, one may capitalise on a familiar regime of managing self-presentation by creating and then moving into and out of intra-space locales, each associated with a particular set of identities and audiences.

http://www.cs.bath.ac.uk/Leon/papers/WattsDuboisIHM-HCI.pdf

Managing Visibility in Ubiquitous Multimedia Communication Environments

Mixed interactive systems (MIS) denote an advanced form of interaction that aims at combining physical and digital worlds, such as mixed and augmented reality, tangible user interfaces, ubiquitous computing, etc. Their main interest relates to the use of physical artifacts from the user’s activity customary context. These can support partly the user communication with the interactive system: personal belongings and everyday physical objects are very familiar to users for smoothly interacting with the system. Initially limited to very specific domains, MIS now appear in many domains, thus motivating the need for adapted design supports. Beyond the technological issues and challenges, the variety of entities involved and the originality of the conditions of use, innovative interaction forms also trigger the need to focus on the elaboration of a solid, structured and common usability knowledge dedicated to MIS. In this chapter, we first report on a systematic review of the literature on MIS evaluation. From that review, usability recommendations were selected and deciphered before reformulating them under a common format. Finally, three different classification schemes of the usability recommendations obtained are proposed to facilitate search and retrieval, but also to better integrate them into the MIS development process.

Usability Recommendations for Mixed Interactive Systems: Extraction and Integration in a Design Process

Thinned CMOS chips transfer-bonded onto a compliant host substrate remain to date the technology of choice for applications requiring both mechanical flexibility and high frequency operation. However, the use of poorly thermally conductive host substrates raises the problem of thermal management of flexible electronics, a topic poorly addressed in literature. In this letter, we report the analysis of flexible SOI-CMOS chips ultimately-thinned-and-transfer-bonded (UTTB) onto polyimide and copper substrates. While the temperature remains limited to ~68°C on the native silicon substrate or after transfer onto a copper host substrate, infrared thermography reveals temperature peaks of up to 118°C on polyimide. The impact of self-heating in flexible SOI-CMOS is correlated with electrical performance for the three types of substrates. Beyond the property of mechanical flexibility it provides, a copper substrate is shown to slightly strengthen electrostatic integrity while maintaining a thermal landscape close to that of silicon.

https://hal.archives-ouvertes.fr/hal-02317229/document

Emmanuel Dubois

Papers

Interaction Tangible sur Table, définitions et modèles

Interaction Tangible sur Table, un cadre fédérateur illustré

Managing Visibility in Ubiquitous Multimedia Communication Environments

Usability Recommendations for Mixed Interactive Systems: Extraction and Integration in a Design Process

Thermal Analysis of Ultimately-Thinned-and-Transfer-Bonded CMOS on Mechanically Flexible Foils