Microsoft Access | EPFL Graph Search

Microsoft Access (officiellement Microsoft Office Access) est une base de données relationnelle éditée par Microsoft. Ce logiciel fait partie de la suite Microsoft Office. MS Access est composé de plusieurs programmes : le moteur de base de données Microsoft Jet, un éditeur graphique, une interface de type Query by Example pour interroger les bases de données, et le langage de programmation Visual Basic for Applications. Depuis les premières versions, l'interface de Microsoft Access permet de gérer graphiquement des collections de données dans des tables, d'établir des relations entre ces tables selon les règles habituelles des bases de données relationnelles, de créer des requêtes avec le QBE (Query by Example, ou directement en langage SQL), de créer des interfaces homme/machine et des états d'impression. Comme pour les autres logiciels Office, le VBA,Visual Basic for Applications, permet de créer des applications complètes et en réseau local, y compris en utilisant, créant ou modi

An informed environment for inhabited city simulation

In combination with the rapid technical improvements of computers, building large virtual scenes has become a popular field in computer graphics for education, films or games. Often, virtual humans populate scenes such as real reconstructed city, disappeared building or virtual town, and they are expected to provide a real life feeling. The specific aim of this thesis is to perform action planning in order to populate these scenes with virtual humans. To achieve this goal, we use a database dedicated to urban life simulation called an Informed Environment. This report presents a design methodology and associated tools for animation purposes in large scale scenes. We propose a space decomposition of the scene into a set of entities allowing automatic path computing regardless of scene size. In order to achieve human behavioural simulation, we decide to focus on the definition of scene decomposition resulting in the creation of a database. The first stage of this work consisted of building a database simulating "urban knowledge" (knowledge about location and associated functionalities) and virtual perceptions (contact with the ground, object perception etc.). These virtual perceptions, necessary for autonomy simulation, but highly costly in time processor consuming, are simulated through database access corresponding to our Informed Environment. We decided to define an ideal 3D model as a test-bed for concepts and tools, integrating both geometrical and semantical data. We also define rules for the design, storage and display options. The "urban knowledge" attached to a simulation is the base of a generic hierarchical model of space decomposition. This model of space decomposition of the 3D scene is related to a specific type of simulation and directly applied to the modelling of the tridimensional scene. Once the database is created, some tools access the database content for path/action computation, knowledge concerning a place, display optimization, places and objects. As 3D data visibility and verification with associated semantic information are difficult to observe, we have defined some tools for database visualisation, verification and modification (the "applicity" software). These tools have been developed in order to offer assistance to the user during manipulation of three-dimensional data. This system is applied to real reconstructed scenes in the framework of the European project CROSSES, for panic simulation during accident. Our field of research has also been extended to the domain of disability help in order to compute path for people with reduced mobility. Our goal was to define some tools and a few constraint methodology that automatically generate all information needed for simulating autonomous behaviour in an urban environment.

EPFL2001

BuMP: Bulk Memory Access Prediction and Streaming

Babak Falsafi, Boris Robert Grot, Javier Picorel Obando, Stavros Volos

With the end of Dennard scaling, server power has emerged as the limiting factor in the quest for more capable datacenters. Without the benefit of supply voltage scaling, it is essential to lower the energy per operation to improve server efficiency. As the industry moves to lean-core server processors, the energy bottleneck is shifting toward main memory as a chief source of server energy consumption in modern datacenters. Maximizing the energy efficiency of today's DRAM chips and interfaces requires amortizing the costly DRAM page activations over multiple row buffer accesses. This work introduces Bulk Memory Access Prediction and Streaming, or BuMP. We make the observation that a significant fraction (59-79%) of all memory accesses fall into DRAM pages with high access density, meaning that the majority of their cache blocks will be accessed within a modest time frame of the first access. Accesses to high-density DRAM pages include not only memory reads in response to load instructions, but also reads stemming from store instructions as well as memory writes upon a dirty LLC eviction. The remaining accesses go to low-density pages and virtually unpredictable reference patterns (e.g., hashed key lookups). BuMP employs a low-cost predictor to identify high-density pages and triggers bulk transfer operations upon the first read or write to the page. In doing so, BuMP enforces high row buffer locality where it is profitable, thereby reducing DRAM energy per access by 23%, and improves server throughput by 11% across a wide range of server applications.

2014

Multi-Tone Signaling and ADC-Based Digital Receiver for High-Speed Wireline Serial Links

Gain Kim

The exponential growth of Internet traffic and related demands for higher communication speed pushes processor-to-processor and processor-to-memory interconnects to provide further higher data-rate. Often time, processor-to-memory interconnectsâ speed is limited by reflections due to their multi-drop bus (MDB) channel nature, and processor-to-processor interconnectsâ speed is limited by inter-symbol interference due to the slowly-decaying channel pulse response and the operating speed and/or power efficiency of the equalization circuits. For the data-rate to continue its exponential growth, more complex modulation and equalization techniques should be employed in the transmitter (TX) and receiver (RX) circuits, given the power and silicon area budget. This thesis presents a signaling scheme designed to overcome equalization challenges related to reflection-limited interfaces such as MDB interfaces. By shaping the spectrum of the transmitted signal appropriately to the channelâs frequency characteristics, the proposed signaling enables minimization of energy-loss due to reflections. While the data-rate of conventional non-return-to-zero (NRZ) signaling over MDB is limited by its first notch frequency unless power-hungry decision-feedback equalizer (DFE) is employed, the proposed signaling scheme allows overcoming such limitation by simple encoding and decoding. Analogmulti-tone (AMT) signaling with single-sideband (SSB) radio-frequency (RF)-bands for efficient bandwidth usage is proposed for lossy point-to-point interfaces. The mutually orthogonal RF sub-bands feature self-equalization throughout the propagation through the communication medium and down-conversion at the RX, without necessitating the presence of conventional equalizers. To enable communication with higher modulation order for more efficient bandwidth utilization, an analog-to-digital converter (ADC)-based discrete multi-tone (DMT) RX is designed and implemented. Thanks to the high bandwidth efficiency of approximately 5.33 bits/Hz (including the cyclic prefix of DMT symbol) using 64-level quadrature amplitude modulation (64-QAM), the implemented RX undergoes less channel attenuation as compared to its 4-level pulse amplitude modulation (PAM-4) counterpart given target communication speed through the same channel. Moreover, the inherently parallel RX architecture of DMT signaling allows the RX digital signal processing (DSP) elements to be designed in semi-custom style without stringent timing constraints. Finally, a PAM-4 RX based on ADC with fully-digital equalization is presented. With register-transfer level (RTL) modeling of the designed digital equalizer, the results demonstrate the feasibility of frequency-domain equalization of the time-domain signal using Fourier transform and its inversion. The proposed frequency-domain equalization technique removes the necessity of symbol-by-symbol feedback loop in DSP that is present in DFE, relaxing critical timing constraints in DSP synthesis.

EPFL2018

Multi-Tone Signaling and ADC-Based Digital Receiver for High-Speed Wireline Serial Links

Gain Kim

EPFL2018

An informed environment for inhabited city simulation

EPFL2001