Christophe Bobda

Prof. Christophe Bobda

1. Computer Science and Computer Engineering, University of Arkansas, JBHT 515, Fayetteville, AR 72701, USA
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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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4 February 2022 in ACM Transactions on Reconfigurable Technology and Systems
Verified
Journal Article
Open access
Christophe BobdaChristophe Bobda
Christophe Bobda
JMJoel Mandebi Mbongue
Joel Mandebi Mbongue
PCPaul Chow
Paul Chow
MEMohammad Ewais
Mohammad Ewais
NTNaif Tarafdar
Naif Tarafdar
RTRussell Tessier
Russell Tessier
In this article, we survey existing academic and commercial efforts to provide Field-Programmable Gate Array (FPGA) acceleration in datacenters and the cloud. The goal is a critical review of existing systems and a discussion of their evolution from single workstations with PCI-attached FPGAs in the early days of reconfigurable computing to the integration of FPGA farms in large-scale computing infrastructures. From the lessons learned, we discuss the future of FPGAs in datacenters and the cloud and assess the challenges likely to be encountered along the way. The article explores current architectures and discusses scalability and abstractions supported by operating systems, middleware, and virtualization. Hardware and software security becomes critical when infrastructure is shared among tenants with disparate backgrounds. We review the vulnerabilities of current systems and possible attack scenarios and discuss mitigation strategies, some of which impact FPGA architecture and technology. The viability of these architectures for popular applications is reviewed, with a particular focus on deep learning and scientific computing. This work draws from workshop discussions, panel sessions including the participation of experts in the reconfigurable computing field, and private discussions among these experts. These interactions have harmonized the terminology, taxonomy, and the important topics covered in this manuscript.

24 January 2013 in Sensors
Verified
Journal Article
Open access
PDF file
VDVolker Dworak
Volker Dworak
JSJoern Selbeck
Joern Selbeck
KDKarl-Heinz Dammer
Karl-Heinz Dammer
MHMatthias Hoffmann
Matthias Hoffmann
AZAli Akbar Zarezadeh
Ali Akbar Zarezadeh
Christophe BobdaChristophe Bobda
Christophe Bobda
The application of (smart) cameras for process control, mapping, and advanced imaging in agriculture has become an element of precision farming that facilitates the conservation of fertilizer, pesticides, and machine time. This technique additionally reduces the amount of energy required in terms of fuel. Although research activities have increased in this field, high camera prices reflect low adaptation to applications in all fields of agriculture. Smart, low-cost cameras adapted for agricultural applications can overcome this drawback. The normalized difference vegetation index (NDVI) for each image pixel is an applicable algorithm to discriminate plant information from the soil background enabled by a large difference in the reflectance between the near infrared (NIR) and the red channel optical frequency band. Two aligned charge coupled device (CCD) chips for the red and NIR channel are typically used, but they are expensive because of the precise optical alignment required. Therefore, much attention has been given to the development of alternative camera designs. In this study, the advantage of a smart one-chip camera design with NDVI image performance is demonstrated in terms of low cost and simplified design. The required assembly and pixel modifications are described, and new algorithms for establishing an enhanced NDVI image quality for data processing are discussed.

7 May 2013 in Journal of Real-Time Image Processing
Verified
Journal Article
Closed access
PDF file
JAJakob Anders
Jakob Anders
MMMichael Mefenza
Michael Mefenza
Christophe BobdaChristophe Bobda
Christophe Bobda
FYFranck Yonga
Franck Yonga
ZAZeyad T. Aklah
Zeyad T. Aklah
KGKevin Gunn
Kevin Gunn

12 April 2025 in ACM Transactions on Reconfigurable Technology and Systems
Verified
Journal Article
Open access
MAMuhammed Kawser Ahmed
Muhammed Kawser Ahmed
MKMaximillian Panoff Kealoha
Maximillian Panoff Kealoha
JMJoel Mandebi Mbongue
Joel Mandebi Mbongue
SSSujan Kumar Saha
Sujan Kumar Saha
ETErman Nghonda Tchinda
Erman Nghonda Tchinda
Christophe BobdaChristophe Bobda
Christophe Bobda
With the growing demand for enhanced performance and scalability in cloud applications and systems, data center architectures are evolving to incorporate heterogeneous computing fabrics that leverage CPUs, GPUs, and FPGAs. Unlike traditional processing platforms like CPUs and GPUs, FPGAs offer the unique ability for hardware reconfiguration at runtime, enabling improved and tailored performance, flexibility, and acceleration. FPGAs excel at executing large-scale search optimization, acceleration, and signal processing tasks while consuming low power and minimizing latency. Major public cloud providers, such as Amazon, Huawei, Microsoft, Alibaba, and others, have already begun integrating FPGA-based cloud acceleration services into their offerings. Although FPGAs in cloud applications facilitate customized hardware acceleration, they also introduce new security challenges that demand attention. Granting cloud users the capability to reconfigure hardware designs after deployment may create potential vulnerabilities for malicious users, thereby jeopardizing entire cloud platforms. In particular, multi-tenant FPGA services, where a single FPGA is divided spatially among multiple users, are highly vulnerable to such attacks. This article examines the security concerns associated with multi-tenant cloud FPGAs, provides a comprehensive overview of the related security, privacy and trust issues, and discusses forthcoming challenges in this evolving field of study.

Verified
Journal Article
Open access
PDF file
CFCedrique Fotsing
Cedrique Fotsing
NNNafissetou Nziengam
Nafissetou Nziengam
Christophe BobdaChristophe Bobda
Christophe Bobda
Point cloud registration combines multiple point cloud data sets collected from different positions using the same or different devices to form a single point cloud within a single coordinate system. Point cloud registration is usually achieved through spatial transformations that align and merge multiple point clouds into a single globally consistent model. In this paper, we present a new segmentation-based approach for point cloud registration. Our method consists of extracting plane structures from point clouds and then, using the 4-Point Congruent Sets (4PCS) technique, we estimate transformations that align the plane structures. Instead of a global alignment using all the points in the dataset, our method aligns 2-point clouds using their local plane structures. This considerably reduces the data size, computational workload, and execution time. Unlike conventional methods that seek to align the largest number of common points between entities, the new method aims to align the largest number of planes. Using partial point clouds of multiple real-world scenes, we demonstrate the superiority of our method compared to raw 4PCS in terms of quality of result (QoS) and execution time. Our method requires about half the execution time of 4PCS in all the tested datasets and produces better alignment of the point clouds.

10 March 2021 in Sensors
Verified
Journal Article
Open access
PDF file
Md Jubaer Hossain PanthoMd Jubaer Hossain Pantho
Md Jubaer Hossain Pantho
PBPankaj Bhowmik
Pankaj Bhowmik
Christophe BobdaChristophe Bobda
Christophe Bobda
The astounding development of optical sensing imaging technology, coupled with the impressive improvements in machine learning algorithms, has increased our ability to understand and extract information from scenic events. In most cases, Convolution neural networks (CNNs) are largely adopted to infer knowledge due to their surprising success in automation, surveillance, and many other application domains. However, the convolution operations’ overwhelming computation demand has somewhat limited their use in remote sensing edge devices. In these platforms, real-time processing remains a challenging task due to the tight constraints on resources and power. Here, the transfer and processing of non-relevant image pixels act as a bottleneck on the entire system. It is possible to overcome this bottleneck by exploiting the high bandwidth available at the sensor interface by designing a CNN inference architecture near the sensor. This paper presents an attention-based pixel processing architecture to facilitate the CNN inference near the image sensor. We propose an efficient computation method to reduce the dynamic power by decreasing the overall computation of the convolution operations. The proposed method reduces redundancies by using a hierarchical optimization approach. The approach minimizes power consumption for convolution operations by exploiting the Spatio-temporal redundancies found in the incoming feature maps and performs computations only on selected regions based on their relevance score. The proposed design addresses problems related to the mapping of computations onto an array of processing elements (PEs) and introduces a suitable network structure for communication. The PEs are highly optimized to provide low latency and power for CNN applications. While designing the model, we exploit the concepts of biological vision systems to reduce computation and energy. We prototype the model in a Virtex UltraScale+ FPGA and implement it in Application Specific Integrated Circuit (ASIC) using the TSMC 90nm technology library. The results suggest that the proposed architecture significantly reduces dynamic power consumption and achieves high-speed up surpassing existing embedded processors’ computational capabilities.