• Journal of Korean Institute of Industrial Engineers
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• v.39 no.2
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• pp.82-89
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• 2013

Novelty detection (ND) is an effective technique that can be used to determine whether a future observation is normal or not. In the present study we propose a novelty detection algorithm that can handle a situation where the distributions of target (normal) observations are inhomogeneous. A simulation study and a real case with the TFT-LCD process demonstrated the effectiveness and usefulness of the proposed algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1416-1424
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• 1996

The problem of optimaizing multiframe targe detection (MFTD) performance si discussed. The MFTD problem is treated as a multiple hypothesis desision problem, and a ne optimality criterion for the MFTD problem is established. It is of Neyman-Pearson (NP) type which is extended to multiple hypothesis cases. An optimal solution with respect tot eh established criterion is derived, and also proposed is a suboptimal solution which reduces the compelexity accompanying the optimal one. The trade-off between the reduction of complexity and the amount of loss in the detection performance is also studied. The proposed algorithm is applied to an active sonar system and the performance is evaluated via Monte-Carlo simulations.

• Journal of Information Processing Systems
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• v.17 no.1
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• pp.124-135
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• 2021

Object detection is a fundamental yet challenging task in computer vision that plays an important role in object recognition, tracking, scene analysis and understanding. This paper aims to propose a multiproperty fusion algorithm for moving object detection. First, we build a scale-invariant feature transform (SIFT) vector field and analyze vectors in the SIFT vector field to divide vectors in the SIFT vector field into different classes. Second, the distance of each class is calculated by dispersion analysis. Next, the target and contour can be extracted, and then we segment the different images, reversal process and carry on morphological processing, the moving objects can be detected. The experimental results have good stability, accuracy and efficiency.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.4
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• pp.120-128
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• 2012

In this paper, we propose a modified iterative pre-whitening projection statistics (MIPPS) scheme for improving multi-target detection performance in non-homogeneous clutter environments. As a non-homogeneity detection (NHD) technique of space-time adaptive processing algorithm for airborne radar, the MIPPS scheme improves the average detection probability of weak target when multiple targets with different reflection signal intensities are located in close range. Numerical results show that the conventional NHD schemes suffers from the masking effect by strong targets and clutters and the proposed MIPPS scheme outperforms the conventional schemes with respect to the average detection probability of the weak target at low signal-to-clutter ratio.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.2
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• pp.225-234
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• 2018

In this paper, we consider a problem of partitioning a search area into smaller rectangular regions, so that multiple platforms can conduct search operations independently without requiring unnecessary coordination among themselves. The search area consists of cells where each cell has some prior information regarding the probability of target existence. The detection probability in particular cell is evaluated by multiplying the observation probability of the platform and the target existence probability in that cell. The total detection probability within the search area is defined as the cumulative detection probability for each cell. However, since this search area partitioning problem is NP-Hard, we decompose the problem into three sequential phases to solve this computationally intractable problem. Additionally, we discuss a special case of this problem, which can provide an optimal analytic solution. We also examine the performance of the proposed approach by comparing our results with the optimal analytic solution.

• The Journal of the Acoustical Society of Korea
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• v.39 no.4
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• pp.237-245
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• 2020

In decades, active sonar, which transmits signals and detects incident signals reflected by underwater targets, has been significantly studied since passive sonar in Anti-Submarine Warfare (ASW) detection performance becomes lowered, as underwater threats become their radiated noise reduced. In general, active sonar using Hull-Mounted Sonar (HMS) adjusts vertical tilt (depression) and sequentially transmits multiple Linear Frequency Modulation (LFM) subpulses which have non-overlapped bands, i. e. 1 kHz ~ 2 kHz, 2 kHz ~ 3 kHz, in order to reduce shadow zones. Recently, however, Generalized SFM (GSFM), which is generalized form of SFM, is proposed, and it is confirmed that subpulses of GSFM have orthogonality among each other depending on setting of GSFM parameters. Hence, in this paper, we applied GSFM to active target detection using HMS to improve the performance by the signal processing gain obtained from enlarged bandwidths of GSFM subpulses compared to those of LFM subpulses. Through simulation, we verified that when the number of subpulses is three, the matched filter gain of GSFM is approximately 5 dB higher than that of LFM.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.2 s.17
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• pp.32-40
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• 2004

In this paper, a simulation model for FLAS(Fixed Linear Arrays System) is presented and methods for effectiveness analysis are studied to analyze the valid target detection effectiveness of this system. The simulation model is constructed taking the FLAS operational specification into account, and thus the change in system specification is effectively reflected on the simulation results. The computational burden is reduced by using the pre-processed simulation parameters which are calculated from the real environmental database. Also, the cell effectiveness and TMOE(Total Measurement of Effectiveness) are computed. The target detection effectiveness of FLAS can be simulated under the multiple target interference simulation. It is shown that the presented algorithm is suitable for the underwater system which needs the simulation model for the optimum system design.

• Journal of Korea Multimedia Society
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• v.24 no.3
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• pp.416-422
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• 2021

Due to the large differences in human activity within classes, the large similarity between classes, and the problems of visual angle and occlusion, it is difficult to extract features manually, and the detection rate of human behavior is low. In order to better solve these problems, an improved Faster R-CNN-based detection algorithm is proposed in this paper. It achieves multi-object recognition and localization through a second-order detection network, and replaces the original feature extraction module with Dense-Net, which can fuse multi-level feature information, increase network depth and avoid disappearance of network gradients. Meanwhile, the proposal merging strategy is improved with Soft-NMS, where an attenuation function is designed to replace the conventional NMS algorithm, thereby avoiding missed detection of adjacent or overlapping objects, and enhancing the network detection accuracy under multiple objects. During the experiment, the improved Faster R-CNN method in this article has 84.7% target detection result, which is improved compared to other methods, which proves that the target recognition method has significant advantages and potential.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.2
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• pp.101-107
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• 2022

In this article, we propose a new protocol at fast scan mode for a sea-surface small target detection. The conventional fast scan mode is composed of coherent intrascan integration to suppress sea clutter and non-coherent interscan integration to exclude sea spikes. The proposed method realizes the coherent interscan integration by the new Fourier relationship between carrier-frequency and initial-radial-range, which can be analytically derived by using multiple carrier frequencies at fast scan mode, leading to improved detection performance, compared to the conventional non-coherent methods. In simulations, our proposed method is verified.

• Science of Emotion and Sensibility
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• v.20 no.2
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• pp.137-148
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• 2017

The present study examined the effect of stimulus contrast and color on detection of a target embedded in streams of letters. In Experiment 1, each trial displayed four rapid serial visual presentation (RSVP) streams of letters (i.e., multi-RSVP), and each stream occupied one of four different locations. Each frame in the RSVP stream had four white distractors at the locations except one frame where a dim grey target was displayed at a location with three white distractors at the remaining locations. In the low-visibility target condition, the target's grey color was slightly darker than the background grey whereas much dimmer in the high-visibility condition. Participants were asked to report presence of a predesignated target as quickly and accurately as possible upon its detection in each trial, and their target detection turned out more accurate and quicker in the high-visibility than the low-visibility condition. In Experiment 2, the same RSVP displays and task as Experiment were used, but the grey target letters in the high-visibility condition were replaced with those of distinct chromatic colors. Participants detected target presence more accurately in the high-visibility condition, but the reaction time did not differ between the visibility conditions. The results indicate that higher stimulus contrast as well as distinct color can improve perception of a target stimulus displayed among visually-demanding background, but also suggest that stimulus contrast may play a more substantial role for such perceptual improvement.