Search results for "emulator"

Physics-Aware Gaussian Processes for Earth Observation

2017

Earth observation from satellite sensory data pose challenging problems, where machine learning is currently a key player. In recent years, Gaussian Process (GP) regression and other kernel methods have excelled in biophysical parameter estimation tasks from space. GP regression is based on solid Bayesian statistics, and generally yield efficient and accurate parameter estimates. However, GPs are typically used for inverse modeling based on concurrent observations and in situ measurements only. Very often a forward model encoding the well-understood physical relations is available though. In this work, we review three GP models that respect and learn the physics of the underlying processes …

Automatic emulator and optimized look-up table generation for radiative transfer models

2017

This paper introduces an automatic methodology to construct emulators for costly radiative transfer models (RTMs). The proposed method is sequential and adaptive, and it is based on the notion of the acquisition function by which instead of optimizing the unknown RTM underlying function we propose to achieve accurate approximations. The Automatic Gaussian Process Emulator (AGAPE) methodology combines the interpolation capabilities of Gaussian processes (GPs) with the accurate design of an acquisition function that favors sampling in low density regions and flatness of the interpolation function. We illustrate the good capabilities of the method in toy examples and for the construction of an…

AI for Resource Allocation and Resource Allocation for AI: a two-fold paradigm at the network edge

2022

5G-and-beyond and Internet of Things (IoT) technologies are pushing a shift from the classic cloud-centric view of the network to a new edge-centric vision. In such a perspective, the computation, communication and storage resources are moved closer to the user, to the benefit of network responsiveness/latency, and of an improved context-awareness, that is, the ability to tailor the network services to the live user's experience. However, these improvements do not come for free: edge networks are highly constrained, and do not match the resource abundance of their cloud counterparts. In such a perspective, the proper management of the few available resources is of crucial importance to impr…

Pusautomātiskā testēšana ar mobilo ierīču emulatoriem un monitoru sienu

2019

Ir nepieciešama kvalitatīva testēšana, lai gūtu pārliecību par izstrādāto sistēmu. Sistēmas testus ir iespējams veikt gan manuāli, gan automatizēti, un ir izveidoti populāri paņēmieni un formulas, kā noteikt, vai konkrētos sistēmas testus labāk veikt vienā vai citā veidā. Piemēram, balstoties uz testēšanas izmaksām vai priekšrocībām. Tomēr katrs no šiem testēšanas veidiem ir ļoti ierobežots. Testējot manuāli, regresā testēšana ar laiku kļūst pārāk laikietilpīga, un, testējot automatizēti, sarežģīti ir identificēt vizuālos defektus. Tika izveidots un pētīts pusautomātiskās testēšanas ietvars, ar kura palīdzību būtu iespējams apvienot manuālās un automatizētās testēšanas labākos aspektus, tād…

FPGA implementation of a fuel cell emulator

2010

Fuel cell based systems are usually tested with the aid of high-cost and complex auxiliary devices. A fuel cell emulator is an attractive solution for preliminary downward system test. The emulator replaces the effective power source saving cost, volume and hydrogen reserve still ensuring high-accuracy of test results. The use of a highperformance fuel cell model is essential for a successful conclusion of the overall design process. Although the proposed emulator is suitable for each fuel cell type and power level, a 10W Proton Exchange Membrane Fuel Cell emulator is designed and tested. An FPGA based controller models the fuel cell steady-state and dynamic behaviour, including temperature…

A fuel cell model emulator, including temperature effects

2010

Research on the model emulator and experiment checkout of the fuel cell

2011

Multioutput Automatic Emulator for Radiative Transfer Models

2018

This paper introduces a methodology to construct emulators of costly radiative transfer models (RTMs). The proposed methodology is sequential and adaptive, and it is based on the notion of acquisition functions in Bayesian optimization. Here, instead of optimizing the unknown underlying RTM function, one aims to achieve accurate approximations. The Automatic Multi-Output Gaussian Process Emulator (AMO-GAPE) methodology combines the interpolation capabilities of Gaussian processes (GPs) with the accurate design of an acquisition function that favors sampling in low density regions and flatness of the interpolation function. We illustrate the promising capabilities of the method for the const…

An Emulator Toolbox to Approximate Radiative Transfer Models with Statistical Learning

2015

Physically-based radiative transfer models (RTMs) help in understanding the processes occurring on the Earth’s surface and their interactions with vegetation and atmosphere. When it comes to studying vegetation properties, RTMs allows us to study light interception by plant canopies and are used in the retrieval of biophysical variables through model inversion. However, advanced RTMs can take a long computational time, which makes them unfeasible in many real applications. To overcome this problem, it has been proposed to substitute RTMs through so-called emulators. Emulators are statistical models that approximate the functioning of RTMs. Emulators are advantageous in real practice because…

Improving MLC flash performance and endurance with extended P/E cycles

2015

The traditional usage pattern for NAND flash memory is the program/erase (P/E) cycle: the flash pages that make a flash block are all programmed in order and then the whole flash block needs to be erased before the pages can be programmed again. The erase operations are slow, wear out the medium, and require costly garbage collection procedures. Reducing their number is therefore beneficial both in terms of performance and endurance. The physical structure of flash cells limits the number of opportunities to overcome the 1 to 1 ratio between programming and erasing pages: a bit storing a logical 0 cannot be reprogrammed to a logical 1 before the end of the P/E cycle. This paper presents a t…