Javier Alejandro Varela

Mr. Javier Alejandro Varela


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2015
Verified
Book Chapter
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JVJavier Alejandro Varela
Javier Alejandro Varela
CBChristian Brugger
Christian Brugger
STSongyin Tang
Songyin Tang
NWNorbert Wehn
Norbert Wehn
RKRalf Korn
Ralf Korn

3 September 2021 in Journal of Imaging
Verified
Journal Article
Open access
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MTMenbere Kina Tekleyohannes
Menbere Kina Tekleyohannes
VRVladimir Rybalkin
Vladimir Rybalkin
MGMuhammad Mohsin Ghaffar
Muhammad Mohsin Ghaffar
JVJavier Alejandro Varela
Javier Alejandro Varela
NWNorbert Wehn
Norbert Wehn
ADAndreas Dengel
Andreas Dengel
In recent years, there has been an increasing demand to digitize and electronically access historical records. Optical character recognition (OCR) is typically applied to scanned historical archives to transcribe them from document images into machine-readable texts. Many libraries offer special stationary equipment for scanning historical documents. However, to digitize these records without removing them from where they are archived, portable devices that combine scanning and OCR capabilities are required. An existing end-to-end OCR software called anyOCR achieves high recognition accuracy for historical documents. However, it is unsuitable for portable devices, as it exhibits high computational complexity resulting in long runtime and high power consumption. Therefore, we have designed and implemented a configurable hardware-software programmable SoC called iDocChip that makes use of anyOCR techniques to achieve high accuracy. As a low-power and energy-efficient system with real-time capabilities, the iDocChip delivers the required portability. In this paper, we present the hybrid CPU-FPGA architecture of iDocChip along with the optimized software implementations of the anyOCR. We demonstrate our results on multiple platforms with respect to runtime and power consumption. The iDocChip system outperforms the existing anyOCR by 44× while achieving 2201× higher energy efficiency and a 3.8% increase in recognition accuracy.

18 October 2016 in Risks
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Journal Article
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SDSascha Desmettre
Sascha Desmettre
RKRalf Korn
Ralf Korn
JVJavier Alejandro Varela
Javier Alejandro Varela
NWNorbert Wehn
Norbert Wehn
Risk analysis and management currently have a strong presence in financial institutions, where high performance and energy efficiency are key requirements for acceleration systems, especially when it comes to intraday analysis. In this regard, we approach the estimation of the widely-employed portfolio risk metrics value-at-risk (VaR) and conditional value-at-risk (cVaR) by means of nested Monte Carlo (MC) simulations. We do so by combining theory and software/hardware implementation. This allows us for the first time to investigate their performance on heterogeneous compute systems and across different compute platforms, namely central processing unit (CPU), many integrated core (MIC) architecture XeonPhi, graphics processing unit (GPU), and field-programmable gate array (FPGA). To this end, the OpenCL framework is employed to generate portable code, and the size of the simulations is scaled in order to evaluate variations in performance. Furthermore, we assess different parallelization schemes, and the targeted platforms are evaluated and compared in terms of runtime and energy efficiency. Our implementation also allowed us to derive a new algorithmic optimization regarding the generation of the required random number sequences. Moreover, we provide specific guidelines on how to properly handle these sequences in portable code, and on how to efficiently implement nested MC-based VaR and cVaR simulations on heterogeneous compute systems.