• Asian Journal of Atmospheric Environment
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• v.11 no.4
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• pp.322-329
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• 2017

Perturbation in ambient particulate matter ($PM_1$, $PM_{2.5}$, $PM_{10}$) and black carbon (BC) concentrations was studied during a firecracker bursting episode in Diwali (Festival of Lights) celebrations in Nagpur, India. Firecracker bursting resulted in greater escalation in fine particulates over coarse particulates while $PM_{2.5}$ was found to be dominated by $PM_1$ concentration. On the Diwali day, daily mean concentration of $PM_{2.5}$ and $PM_{10}$ exceeded Indian National Ambient Air Quality Standards by over 1.8 and 1.5 times, respectively, while daily mean BC concentration on the same day was almost two times higher than the previous day. The BC/$PM_1$ ratio reduced remarkably from about 0.26 recorded before fire-cracker bursting activity to about 0.09 during fire-cracker bursting on Diwali night in spite of simultaneous escalation in ambient BC concentration. Such aberration in BC/$PM_1$ was evidently a result of much higher escalation in $PM_1$ than BC in ambient air during firecracker bursting. The study highlighted strong perturbations in ambient $PM_1$, $PM_{2.5}$, $PM_{10}$ concentrations and BC/$PM_1$ during the firecracker bursting episode. Altered atmospheric BC/$PM_1$ ratios could serve as indicators of firecracker-polluted air and similar BC/$PM_1$ ratios in local and regional air masses might be used as diagnostic ratios for firecracker smoke.

• Journal of the Korea Society of Computer and Information
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• v.29 no.3
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• pp.107-116
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• 2024

In this paper, we analyze the performance of MicroVM when running AI applications on an edge computing environment and whether it can replace current container technology and traditional virtual machines. To achieve this, we set up Docker container, Firecracker MicroVM and KVM virtual machine environments on a Raspberry Pi 4 and executed representative AI applications in each environment. We analyze the inference time, total CPU usage and trends over time and file I/O performance on each environment. The results show that there is no significant performance difference between MicroVM and container when running AI applications. Moreover, on average, a stable inference time over multiple trials was observed on MicroVM. Therefore, we can confirm that executing AI applications using MicroVM instead of container or heavy-weight virtual machine is suitable for an edge computing.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.12-15
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• 2021

This paper is a survey on the advancement of virtualization technology. Virtualization of resources was an inevitable path in modern computer systems. This abstraction of hardware allowed the decoupling of the operating system that manages the hardware and applications' requirements by adding a layer between them. It also led to the application-centric view of computing and light virtual machines, where each represents a computer networking device. As virtualization technology ripens, the performance of virtual machines can only improve. This paper will be introducing how virtualization technology has evolved from Xen to LightVM and Firecracker.

• Explosives and Blasting
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• v.25 no.2
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• pp.23-33
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• 2007

It is difficult to measure a blast noise in the vicinity of tunnel blasting works and the effect of lowering noise changes very highly with types of soundproof materials. So, the main interest of this study focuses on the materials of a soundproof facilities and the method of noise forecast in a near distance. 20 types of the soundproof facilities are established and blast noise is generated using firecracker in a Hume concrete pipe. To analyze the variations of magnitudes of noise and frequency with the soundproof materials and types, the noise and frequency is measured in a short distance next to blast area.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.383-391
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• 2020

Purpose: To identify internal self ignition and ignition caused by external flames in energy storage rooms, and to analyze the difference between ignition due to overheating and ignition caused by external heat sources. Method: membrane melting point measurement, battery external hydrothermal experiment, battery overcharge experiment, comparative analysis of electrode plate during combustion by overcharge and external heat, overcharge combustion characteristics, external hydrothermal fire combustion characteristics, 3.4 (electrode plate comparison) / 3.5 (overcharge) /3.6 (external sequence) analysis experiment. Result: Since the temperature difference was very different depending on the position of the sensor until the fire occurred, it is judged that two temperature sensors per module are not enough to prevent the fire through temperature control in advance. Conclusion: The short circuit acts as an ignition source and ignites the mixed gas, causing a gas explosion. The electrode breaks finely due to the explosion pressure, and the powder-like lithium oxide is sparked like a firecracker by the flame reaction.