• 한국지형공간정보학회:학술대회논문집
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• 2002.11a
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• pp.117-122
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• 2002

Change detection is a useful technology that can be applied to various fields, taking temporal change information with the comparison and analysis among multi-temporal satellite images. Especially, change detection that utilizes high-resolution satellite imagery can be implemented to extract useful change information for many purposes, such as the environmental inspection, the circumstantial analysis of disaster damage, the inspection of illegal building, and the military use, which cannot be achieved by lower middle-resolution satellite imagery. However, because of the special characteristics that result from high-resolution satellite imagery, it cannot use a pixel-based method that is used for low-resolution satellite imagery. Therefore, it must be used a feature-based algorithm based on the geographical and morphological feature. This paper presents the system that builds the change map by digitizing the boundary of the changed object. In this system, we can make the change map using manual or semi-automatic digitizing through the user interface implemented with a floating window that enables to detect the sign of the change, such as the construction or dismantlement, more efficiently.

• Journal of the Korea Society of Computer and Information
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• v.20 no.5
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• pp.21-29
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• 2015

This paper proposes a shot change detection algorithm by using frame segmentation and the object changes among moving blocks. In order to detect the rapid moving changes of objects between two consecutive frames, the moving blocks on the diagonal are defined, and their histograms are calculated. When a block of the current frame is compared to the moving blocks of the next frame, the block histograms are used and the threshold of a shot change detection is automatically adjusted by Otsu's threshold method. The proposed algorithm was tested for the various types of color or gray videos such as films, dramas, animations, and video tapes in National Archives of Korea. The experimental results showed that the proposed algorithm could enhance the detection rate when compared to the studied methods that use brightness, histogram, or segmentation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.3
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• pp.362-370
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• 2011

This paper presents a K-band radar system installed on the ground moving vehicle to detect and track a high-speed target. The presented radar is separated into three search regions to satisfy a wide area detection and a limitation of the installing space of the radar, and each region performs detecting the target independently and tracking the detected target automatically. The presented radar radiating K-band FMCW waveform acquires range and velocity information of the target at the every dwell and receiving antenna of the radar is applied the multiple baseline interferometer to extract the precise angle information of the target. 3-dimensional tracking accuracy of the radar is 0.25 m RMSE measured actually through a fire experiment of an imitation target.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.5
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• pp.91-104
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• 2003

A masquerader is someone who pretends to be another user while invading the target user's accounts, directories, or files. The masquerade attack is the most serious computer misuse. Because, in most cases, after securing the other's password, the masquerader enters the computer system. The system such as IDS could not detect or response to the masquerader. The masquerade detection is the effort to find the masquerader automatically. This system will detect the activities of a masquerader by determining that user's activities violate a profile developed for that user with his audit data. From 1988, there are many efforts on this topic, but the success of the offers was limited and the performance was unsatisfactory. In this report we propose efficient masquerade detection system using SVM which create the user profile.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.4
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• pp.29-39
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• 2009

In order to respond against worms which are malicious programs automatically spreading across communication networks, worm detection approach by generating signatures resulting from analyzing worm-related packets is being mostly used. However, to avoid such signature-based detection techniques, usage of exploits employing mutated polymorphic types are becoming more prevalent. In this paper, we propose a novel static analysis approach for detecting the decryption routine of polymorphic exploit code, Our approach detects a code routine for performing the decryption of the encrypted original code which are contained with the polymorphic exploit code within the network flows. The experiment results show that our approach can detect polymorphic exploit codes in which the static analysis resistant techniques are used. It is also revealed that our approach is more efficient than the emulation-based approach in the processing performance.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.3
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• pp.555-564
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• 2022

Recently, cyberattacks are using hacking techniques utilizing intelligent and advanced malicious codes for non-face-to-face environments such as telecommuting, telemedicine, and automatic industrial facilities, and the damage is increasing. Traditional information protection systems, such as anti-virus, are a method of detecting known malicious URLs based on signature patterns, so unknown malicious URLs cannot be detected. In addition, the conventional static analysis-based malicious URL detection method is vulnerable to dynamic loading and cryptographic attacks. This study proposes a technique for efficiently detecting malicious URLs by dynamically learning malicious URL data. In the proposed detection technique, malicious codes are classified using machine learning-based feature selection algorithms, and the accuracy is improved by removing obfuscation elements after preprocessing using Weighted Euclidean Distance(WED). According to the experimental results, the proposed machine learning-based malicious URL detection technique shows an accuracy of 89.17%, which is improved by 2.82% compared to the conventional method.

• Korean Journal of Cognitive Science
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• v.23 no.2
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• pp.165-184
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• 2012

To investigate how the valence of unattended background picture modulates perceptual processing of a target letter, participants were required to detect a target letter among six letters superimposed on an IAPS picture. Perceptual load was manipulated by varying the difficulty of letter detection, and behavioral results showed more accurate and faster detection responses at the low-load condition than at the high-load condition. The analysis of ERP data of control condition at which six letters were presented without an IAPS picture showed perceptual load effects on mean amplitude of N1 and P1 ERP components. At experimental condition including an IAPS picture, interaction between valence and perceptual load was observed on mean amplitude of N1 at posterior visual processing area, and the amplitude difference between low-load condition and high-load condition was larger on a negative background picture than on a neutral background picture. The results suggest that more attentional capacity might be consumed by a negative picture than by a neutral picture, and suggest that unattended affective picture is processed automatically and influence the early perceptual processing of target stimulus.

• Journal of the Korea Computer Industry Society
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• v.3 no.9
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• pp.1279-1286
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• 2002

Generally, radiologists can fail to detect pulmonary nodules in up to 30%. If an automatic system can inform the radiologists of thelocations of the doubtful nodules in the X-ray chest images, the frequency of mistakenly observed numbers of the nodules can be potentially reduced. This software is using morphological filtering and two feature-extraction techniques. The morphological filtering is the first process, which subsequently adds the operations of erosion and dilation to the original images so that this process can transform the original X-ray chest images into manageable ones. The false-positives are frequently being mistaken as nodules but actually these are not real nodules. The second process is the two feature-extraction techniques which are used to reduce the false-positives. Therefore, this system will make more effective detection of pulmonary nodules by reducing the false-positives when applied to the X-ray chest images which is difficult to get accurate detection.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.93-102
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• 2011

In this paper we describe an efficient and easy to use network monitoring system which can identify network configuration automatically by means of capturing and analyzing the ARP broadcasting packets. After identifying network nodes, it gathers detail information of each node such as NETBIOS name and number of hop counts using ICMP and then shows subnet configuration with graphical method. This monitoring system also has a subset of intrusion detection system that can monitor any port scanning trial. With this automatic network configuration functions, it helps to lessen address keeping track overhead which is crucial for network monitoring so that it provides efficient network management.

• Journal of Biomedical Engineering Research
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• v.24 no.1
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• pp.9-13
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• 2003

An assist device was developed to identify the epidural space by continously monitoring the air-filled catheter pressure. The pressure signal appropriately amplified and filtered enabled to alarm the needle introduction into the epidural space by thresholding detection. Ten LEDs provided a visual change of catheter pressure before alarming for user convenience. Clinical trials were performed in 30 patients with 83% success rate at the first trial. When failed, the second trial was enough for successful anesthesia. The air volume introduced during each anesthesia was less than 1ml, causing side effects. Air filling of the catheter could also minimize infection possibility. Therefore, the present device guarantees safe anesthesia with user convenience.