• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.7
• /
• pp.1518-1523
• /
• 2012

Due to development of visual media in various industrial sectors, the importance of image processing is increasing. Among the various image processing areas, edge detection is utilized widely for various fields such as object recognition, object segmentation, the medical and other industries. Edge includes the critical factors of images like size, direction and location. Then conventional methods such as Sobel, Prewitt, Roberts and Laplacian are proposed to detect edge. However, edge detection property of these methods is declined when they are applied to the image which corrupted by AWGN(Additive White Gaussian Noise). Therefore, an algorithm using modified weighted filter is proposed in this paper and our method has excellent property on edge detection.

• Journal of KIISE
• /
• v.43 no.2
• /
• pp.186-195
• /
• 2016

This paper proposes a vehicle license plate detection method in real road environments using 8 bit-MCT features and a landmark-based Adaboost method. The proposed method allows identification of the potential license plate region, and generates a saliency map that presents the license plate's location probability based on the Adaboost classification score. The candidate regions whose scores are higher than the given threshold are chosen from the saliency map. Each candidate region is adjusted by the local image variance and verified by the SVM and the histograms of the 8bit-MCT features. The proposed method achieves a detection accuracy of 85% from various road images in Korea and Europe.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.12
• /
• pp.5485-5506
• /
• 2016

In this article, a video based fire detection framework for CCTV surveillancesystems is presented. Two novel features and a novel image type with their corresponding algorithmsareproposed for this purpose. One is for the slow-smoke detection and another one is for fast-smoke/flame detection. The basic idea is slow-smoke has a highly varying chrominance/luminance texture in long periods and fast-smoke/flame has a highly varying texture waiting at the same location for long consecutive periods. Experiments with a large number of smoke/flame and non-smoke/flame video sequences outputs promising results in terms of algorithmic accuracy and speed.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.8
• /
• pp.713-717
• /
• 2015

In this paper, we propose camber monitoring system which is using on hot rolling process. In roughing mill which is one of the rolling part in hot rolling process, steel plate can be bended in width direction under the imbalance of rolling condition. This bending of steel plate in width direction is called as camber. In order to measure the camber, first, cameras which are installed over transport pathway of steel plate take pictures of whole shape of steel plate. And location value of steel plate edge is extrated from these pictures by edge detection algorithm. But, there are a lot of noises which are generated by such as water sprays, dusts, peripheral equipments in these pictures, and these noises make edge detection difficult. In order to solve this kind of problem, we developed a direction selective edge detection algorithm, and applicated in our camber monitoring system. As a result, we got stable results in spite of process noises.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.14 no.4
• /
• pp.49-54
• /
• 2005

Measuring defects on the inside and on the surface of a steel structure is very important technology in order to predict the life span of the structure. In particular, a place with a high probability that it may contain defects is a welded part and it is very important to check defects in the part, absence/presence of non-uniform substances, its shape, and the location. Many non-destructive tests can be applied, but the ultrasonic flow detection test is widely used with some advantages. The ultrasonic flow detection test, however, cannot be applied when there is a problem by a contact medium between PZT and a specimen, in case of a small and complicated shape or a moving object or when the specimen is hot. In this study, to solve the problems of the contact ultrasonic flow detection test, the non-contact ultrasonic flow detection test for sending/receiving ultrasonic waves using lasers was described. I intended to develop a non-destructive detection system applying the laser application ultrasonic test to a steel structure by detecting the defects inside of and on the surface of the specimen.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.2
• /
• pp.363-370
• /
• 2021

The perimeter intrusion detection system is very important in physical security. In this study, a micro smart device (module) using MEMS sensor was developed in IoT environment for external intrusion detection. The outer intrusion detection system applying the smart device developed in this study is installed in various installation environments, such as barbed wire of various materials and shapes, the city center, the beach, and the mountain, so that it can detect external intrusion and its location as well as false alarms. As a smart sensor that can minimize the false alarm rate and economical construction cost, it is expected that it can be used for the safe operation of major facilities and prevention of disasters and crimes.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.1
• /
• pp.245-265
• /
• 2022

In response to problems such as insufficient extraction information, low detection accuracy, and frequent misdetection in the field of Thangka image defects, this paper proposes a YOLOv5 prediction algorithm fused with the attention mechanism. Firstly, the Backbone network is used for feature extraction, and the attention mechanism is fused to represent different features, so that the network can fully extract the texture and semantic features of the defect area. The extracted features are then weighted and fused, so as to reduce the loss of information. Next, the weighted fused features are transferred to the Neck network, the semantic features and texture features of different layers are fused by FPN, and the defect target is located more accurately by PAN. In the detection network, the CIOU loss function is used to replace the GIOU loss function to locate the image defect area quickly and accurately, generate the bounding box, and predict the defect category. The results show that compared with the original network, YOLOv5-SE and YOLOv5-CBAM achieve an improvement of 8.95% and 12.87% in detection accuracy respectively. The improved networks can identify the location and category of defects more accurately, and greatly improve the accuracy of defect detection of Thangka images.

• Journal of Sensor Science and Technology
• /
• v.31 no.6
• /
• pp.441-447
• /
• 2022

This study describes a novel method for detecting and measuring partial discharge (PD) on an electrical facility such as an insulated power cable or switchgear using fiber optic sensing technology, and a distributed acoustic sensing (DAS) system. This method has distinct advantages over traditional PD sensing techniques based on an electrical method, including immunity to electromagnetic interference (EMI), long range detection, simultaneous detection for multiple points, and exact location. In this study, we present a DAS system for PD detection with performance evaluation and experimental results in a simulated environment. The results show that the system can be applied to PD detection.

• Structural Engineering and Mechanics
• /
• v.87 no.6
• /
• pp.555-574
• /
• 2023

An efficient optimization algorithm and damage-sensitive objective function are two main components in optimization-based Finite Element Model Updating (FEMU). A suitable combination of these components can considerably affect damage detection accuracy. In this study, a new hybrid damage-sensitive objective function is proposed based on combining two different objection functions to detect the location and extent of damage in structures. The first one is based on Generalized Pseudo Modal Strain Energy (GPMSE), and the second is based on the element's Generalized Flexibility Matrix (GFM). Four well-known population-based metaheuristic algorithms are used to solve the problem and report the optimal solution as damage detection results. These algorithms consist of Cuckoo Search (CS), Teaching-Learning-Based Optimization (TLBO), Moth Flame Optimization (MFO), and Jaya. Three numerical examples and one experimental study are studied to illustrate the capability of the proposed method. The performance of the considered metaheuristics is also compared with each other to choose the most suitable optimizer in structural damage detection. The numerical examinations on truss and frame structures with considering the effects of measurement noise and availability of only the first few vibrating modes reveal the good performance of the proposed technique in identifying damage locations and their severities. Experimental examinations on a six-story shear building structure tested on a shake table also indicate that this method can be considered as a suitable technique for damage assessment of shear building structures.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 1996.11a
• /
• pp.72-75
• /
• 1996

The objectives of this paper investigate the effect of installed spacing on the activation of spot type heat detection devices. The flow of hot gases under a ceiling resulting from the impingement of a fire plume activates heat detectors and sprinklers. Local temperature and velocity in this ceiling jet are usually expressed with the function of a ceiling height, the distance from a fire location and the heat release rate of fire. And detectors having different. RTI respond in different ways to the same temperature and velocity of ceiling jet. Thus great care should be taken to decide installed spacing of heat detection devices by considering above effects.