• Smart Structures and Systems
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• v.32 no.3
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• pp.179-193
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• 2023

This study explores an alternative to the existing centralized process for data anomaly detection in modern Internet of Things (IoT)-based structural health monitoring (SHM) systems. An edge intelligence framework is proposed for the early detection and classification of various data anomalies facilitating quality enhancement of acquired data before transmitting to a central system. State-of-the-art deep neural network pruning techniques are investigated and compared aiming to significantly reduce the network size so that it can run efficiently on resource-constrained edge devices such as wireless smart sensors. Further, depthwise separable convolution (DSC) is invoked, the integration of which with advanced structural pruning methods exhibited superior compression capability. Last but not least, quantization-aware training (QAT) is adopted for faster processing and lower memory and power consumption. The proposed edge intelligence framework will eventually lead to reduced network overload and latency. This will enable intelligent self-adaptation strategies to be employed to timely deal with a faulty sensor, minimizing the wasteful use of power, memory, and other resources in wireless smart sensors, increasing efficiency, and reducing maintenance costs for modern smart SHM systems. This study presents a theoretical foundation for the proposed framework, the validation of which through actual field trials is a scope for future work.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2441-2449
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• 2015

In this digital information era, utilization of images are essential for various media, and the edge is an important characteristical information of an object in images that includes the size, location, direction and etc. Many domestic and international studies are being conducted in order to detect these edge. Existing edge detection methods include Sobel, Prewitt, Roberts, Laplacian, LoG and etc. which apply fixed weight value. As these existing edge detection methods apply fixed weight mask to the image, edge detection characteristic appears slightly insufficient. Accordingly, in order to supplement these problems, this study used bottom-hat transformation from mathematical morphology and opening operation in improving the image and proposed an algorithm that detects for the edge after calculating mask-based gradient. And to evaluate the performance of the proposed algorithm, a comparison was made against the existing Sobel, Roberts, Prewitt, Laplacian, LoG edge detection methods, in illustrating visual images, and similarities were compared by calculating the MSE value based on the standard of each image.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.220-226
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• 2006

The effect of electric fields on the propagation speed of tribrachial flames has been investigated in a coflow jet by observing the transient flame propagation behavior after ignition. Without having electric fields, the propagation speed of tribrachial flame edges showed a typical behavior by having an inverse proportionality to the mixture fraction gradient at the flame edge. The behavior of flame propagation with the electric fields was investigated by applying high voltage to the central fuel nozzle and the enhancement of propagation speed has been observed by varying the applied voltage and frequency for AC electric fields. The propagation speed of tribrachial flame was also investigated by applying negative and positive DC voltages to the nozzle and similar improvements of the propagation speed were also observed. The propagation speeds of tribrachial flames in both the AC and DC electric fields were correlated well with the electric field intensity, defined by the electric voltage divided by the distance between the nozzle electrode and the edge of tribrachial flames.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.95-98
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• 2009

This paper dealt with the design guide of the conventional edge-lit backlight optic with which the on-axis luminance could be increased by trying to improve the light condensing efficiency of a bright enhancement film (BEF). First, the general design guide concerned with the backlight optic was proposed, and then its validness was experimentally proved by conducting design examples with haze controls of both diffuse film and microdot material printed on the backside of the light guide plate. Experimental results showed that the variation range of the on-axis luminance by the present approach was about $5{\sim}9%$, which would be by no means negligible in the practical application.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.21-29
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• 2020

This paper presents an effective single image haze removal using edge-preserving and adaptive transmission estimation to enhance the visibility of outdoor images vulnerable to weather and environmental conditions with computational complexity reduction. The conventional methods involve the time-consuming refinement process. The proposed transmission estimation however does not require the refinement, since it preserves the edges effectively, which selects one between the pixel-based dark channel and the patch-based dark channel in the vicinity of edges. Moreover, we propose an adaptive transmission estimation to improve the visual quality particularly in bright areas like sky. Experimental results with various hazy images represent that the proposed method is superior to the conventional methods in both subjective visual quality and computational complexity. The proposed method can be adopted to compose a haze removal module for realtime devices such as mobile devices, digital cameras, autonomous vehicles, and so on as well as PCs that have enough processing resources.

• Journal of Mechanical Science and Technology
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• v.15 no.8
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• pp.1174-1180
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• 2001

Various experimental data, including mixing areas, cross correlation factors, surface flow patterns on nozzle walls, and far field noise spectra, was used to draw a noise control mechanism in a supersonic jet. In the underexpanded case, mixing of the jet air with ambient air was significantly enhanced as presented before, and mixing noise was also dramatically reduced. Screech tones, in the overexpanded case, were effectively suppressed by trailing edge modifications, although mixing enhancement was not noticeable. From mixing and noise performance of nozzles with modified trailing edges, enhancing mixing through streamwise vortices seems an effective way to reduce mixing noise in the underexpanded flow regime. However, screech tones in the overespanded flow regime is well controlled or suppressed by making shock cells and/or spanwise large scale structures irregular and/or less organized by a proper selection of trailing edges. The noise field in the overexpanded flow regime was greatly affected by the symmetricity of the nozzle exit geometry. In the underexpanded flow regime, the effects of the symmetricity of the nozzle exit on mixing were negligible.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.696-702
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• 2007

This paper proposes a regional feature preserving adaptive interpolation algorithm for natural images. The algorithm can be used in resolution enhancement, arbitrary rotation and other applications of still images. The basic idea is to first scan the sample image to initialize a 2D array which records the edge direction of all four-pixel squares, and then use the array to adapt the interpolation at a higher resolution based on the edge structures. A hybrid approach of switching between bilinear and triangulation-based interpolation is proposed to reduce the overall computational complexity. The experiments demonstrate our adaptive interpolation and show higher PSNR results of about max 2 dB than other traditional interpolation algorithms.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.255-258
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• 2008

For rapidly increasing amount of medical images, it is difficult for radiologist to interpretate the medical images fastly and for sufficient time. We investigated whether liver CT image has good features to be analyzed by computer algorithm, We examed the CT images of liver tumors (Hepetocellular carcinomas; HCCs) and searched any potential morphologic characteristics to be analyzed by computer algorithms. On unenhanced CT, HCCs appeared hypodense After enhancement, most HCCs were hyperdense, and then. as a consequence of rapid washout, HCCS became hypodense compared with the liver parenchyma. Most CT images of HCCs showed synchronous phase-specific.morphologic features. We applied various edge detection filters to these images and some filters showed favorable performance in the detection of tile edge of liver and HCC. Therefore, theses features seems to be analyzed by computer algorithms effectively.Further studies may be warranted.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3367-3371
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• 2013

MgO nanorods were fabricated by the thermal evaporation of $Mg_3N_2$. The influence of ZnO sheathing and hydrogen plasma exposure on the photoluminescence (PL) of the MgO nanorods was studied. PL measurements of the ZnO-sheathed MgO nanorods showed two main emission bands: the near band edge emission band centered at ~380 nm and the deep level emission band centered at ~590 nm both of which are characteristic of ZnO. The near band edge emission from the ZnO-sheathed MgO nanorods was enhanced with increasing the ZnO shell layer thickness. The near band edge emission from the ZnO-sheathed MgO nanorods appeared to be enhanced further by hydrogen plasma irradiation. The underlying mechanisms for the enhancement of the NBE emission from the MgO nanorods by ZnO sheathing and hydrogen plasma exposure are discussed.

• Journal of information and communication convergence engineering
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• v.8 no.4
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• pp.405-410
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• 2010

Image processing operations like smoothing and edge detection, and many more are very widely used in areas like Computer Vision. We classify the image processing domain as seven branches-image acquirement and output, image coding and compression, image enhancement and restoration, image transformation, image segmentation, image description, and image recognition and description. We implemented algorithms of gaussian smoothing, laplace sharpening, image contrast effect, image black and white effect, image fog effect, image bright and dark effect, image median filter, and canny edge detection. Such experimental results show the figures respectively.