A Review on Modern Distributed Computing Paradigms: Cloud Computing, Jungle Computing and Fog Computing

The distributed computing attempts to improve performance in large-scale computing problems by resource sharing. Moreover, rising low-cost computing power coupled with advances in communications/networking and the advent of big data, now enables new distributed computing paradigms such as Cloud, Jungle and Fog computing.Cloud computing brings a number of advantages to consumers in terms of accessibility and elasticity. It is based on centralization of resources that possess huge processing power and storage capacities. Fog computing, in contrast, is pushing the frontier of computing away from centralized nodes to the edge of a network, to enable computing at the source of the data. On the other hand, Jungle computing includes a simultaneous combination of clusters, grids, clouds, and so on, in order to gain maximum potential computing power.To understand these new buzzwords, reviewing these paradigms together can be useful. Therefore, this paper describes the advent of new forms of distributed computing. It provides a definition for Cloud, Jungle and Fog computing, and the key characteristics of them are determined. In addition, their architectures are illustrated and, finally, several main use cases are introduced

Estimation of gillnets selectivity for greater lizardfish, Saurida tumbil (Bloch, 1795) in coastal waters of the Oman Sea: ---

The selectivity of greater lizardfish (Saurida tumbil), which is one of the most abundant economic species caught by gillnets in the northeast of the Oman Sea, Iranian waters, was studied. Sampling was conducted from February to March 2021. Four types of gillnets with mesh sizes of 4.8, 6.3, 10.0, and 15.3 cm were used and 857 fish specimens were collected. The catch patterns, including (snagged, gilled, wedged, and entangled) for S. tumbil were observed in gillnets. For 4.8 and 6.3 cm mesh sizes, more than 70% of the catch was mainly obtained by gilled, followed by wedged, and no found of entanglement. For 10.0 and 15.3 cm mesh sizes, the catch of 10.0 mesh size included 16% of fish caught from wedging, though most of the fish was caught by entanglement. In particular, all catches at 15.3 cm were due to entanglement. Estimation of gillnets selectivity for S. tumbil was performed using the SELECT method. The SELECT method was used to fit three various gillnet selectivity models (log-normal, skew-normal, and bi-normal). Gillnets selectivity was best estimated by a bi-modal Selection curve. The mean lengths ±SE were estimated as 31.48±0.71, 40.3±0.97, 40.1±0.75 and 43.9±1.05 cm for 4.8, 6.3, 10.0 and 15.3 cm mesh sizes, respectively. Mean lengths increased with increasing the mesh size.  Most of the fish caught in the 4.8 and 6.3 cm mesh sizes were below the first maturity length (Lm50). Considering the relative efficiency set as 0.5, that was L50 (50% retention length), the optimal mesh size was determined to be 10.0 cm. Therefore, to protect S. tumbil stock and the sustainability of the fishing resource, the gillnet mesh size should be at 10.0 cm to manage S. tumbil in this area

HyperDbg: Reinventing Hardware-Assisted Debugging (Extended Version)

Software analysis, debugging, and reverse engineering have a crucial impact in today's software industry. Efficient and stealthy debuggers are especially relevant for malware analysis. However, existing debugging platforms fail to address a transparent, effective, and high-performance low-level debugger due to their detectable fingerprints, complexity, and implementation restrictions. In this paper, we present HyperDbg, a new hypervisor-assisted debugger for high-performance and stealthy debugging of user and kernel applications. To accomplish this, HyperDbg relies on state-of-the-art hardware features available in today's CPUs, such as VT-x and extended page tables. In contrast to other widely used existing debuggers, we design HyperDbg using a custom hypervisor, making it independent of OS functionality or API. We propose hardware-based instruction-level emulation and OS-level API hooking via extended page tables to increase the stealthiness. Our results of the dynamic analysis of 10,853 malware samples show that HyperDbg's stealthiness allows debugging on average 22% and 26% more samples than WinDbg and x64dbg, respectively. Moreover, in contrast to existing debuggers, HyperDbg is not detected by any of the 13 tested packers and protectors. We improve the performance over other debuggers by deploying a VMX-compatible script engine, eliminating unnecessary context switches. Our experiment on three concrete debugging scenarios shows that compared to WinDbg as the only kernel debugger, HyperDbg performs step-in, conditional breaks, and syscall recording, 2.98x, 1319x, and 2018x faster, respectively. We finally show real-world applications, such as a 0-day analysis, structure reconstruction for reverse engineering, software performance analysis, and code-coverage analysis

On the resilience of deep learning for reduced-voltage FPGAs

Deep Neural Networks (DNNs) are inherently computation-intensive and also power-hungry. Hardware accelerators such as Field Programmable Gate Arrays (FPGAs) are a promising solution that can satisfy these requirements for both embedded and High-Performance Computing (HPC) systems. In FPGAs, as well as CPUs and GPUs, aggressive voltage scaling below the nominal level is an effective technique for power dissipation minimization. Unfortunately, bit-flip faults start to appear as the voltage is scaled down closer to the transistor threshold due to timing issues, thus creating a resilience issue.This paper experimentally evaluates the resilience of the training phase of DNNs in the presence of voltage underscaling related faults of FPGAs, especially in on-chip memories. Toward this goal, we have experimentally evaluated the resilience of LeNet-5 and also a specially designed network for CIFAR-10 dataset with different activation functions of Rectified Linear Unit (Relu) and Hyperbolic Tangent (Tanh). We have found that modern FPGAs are robust enough in extremely low-voltage levels and that low-voltage related faults can be automatically masked within the training iterations, so there is no need for costly software-or hardware-oriented fault mitigation techniques like ECC. Approximately 10% more training iterations are needed to fill the gap in the accuracy. This observation is the result of the relatively low rate of undervolting faults, i.e., <0.1%, measured on real FPGA fabrics. We have also increased the fault rate significantly for the LeNet-5 network by randomly generated fault injection campaigns and observed that the training accuracy starts to degrade. When the fault rate increases, the network with Tanh activation function outperforms the one with Relu in terms of accuracy, e.g., when the fault rate is 30% the accuracy difference is 4.92%.The research leading to these results has received funding from the European Unions Horizon 2020 Programme under the LEGaTO Project (www.legato-project.eu), grant agreement n 780681.Peer ReviewedPostprint (author's final draft

HyperDbg: Reinventing Hardware-Assisted Debugging

Software analysis, debugging, and reverse engineering have a crucial impact in today's software industry. Efficient and stealthy debuggers are especially relevant for malware analysis. However, existing debugging platforms fail to address a transparent, effective, and high-performance low-level debugger due to their detectable fingerprints, complexity, and implementation restrictions. In this paper, we present StealthDbg, a new hypervisor-assisted debugger for high-performance and stealthy debugging of user and kernel applications. To accomplish this, StealthDbg relies on state-of-the-art hardware features available in today's CPUs, such as VT-x and extended page tables. In contrast to other widely used existing debuggers, we design StealthDbg using a custom hypervisor, making it independent of OS functionality or API. We propose hardware-based instruction-level emulation and OS-level API hooking via extended page tables to increase the stealthiness. Our results of the dynamic analysis of 10,853 malware samples show that StealthDbg's stealthiness allows debugging on average 22% and 26% more samples than WinDbg and x64dbg, respectively. Moreover, in contrast to existing debuggers, StealthDbg is not detected by any of the 13 tested packers and protectors. We improve the performance over other debuggers by deploying a VMX-compatible script engine, eliminating unnecessary context switches. Our experiment on three concrete debugging scenarios shows that compared to WinDbg as the only kernel debugger, StealthDbg performs step-in, conditional breaks, and syscall recording, 2.98x, 1319x, and 2018x faster, respectively. We finally show real-world applications, such as a 0-day analysis, structure reconstruction for reverse engineering, software performance analysis, and code-coverage analysis