• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.1
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• pp.96-107
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• 2014

Tracking the tactical object is a fundamental affair in network-equipped modern warfare. Geodetic coordinate system based on longitude, latitude, and height is suitable to represent the location of tactical objects considering multi platform data fusion. The motion of tactical object described as a dynamic model requires an appropriate filtering to overcome the system and measurement noise in acquiring information from multiple sensors. This paper introduces the filter suitable for multi-sensor data fusion and tactical object tracking, particularly the unscented transform(UT) and its detail. The UT in Unscented Kalman Filter(UKF) uses a few samples to estimate nonlinear-propagated statistic parameters, and UT has better performance and complexity than the conventional linearization method. We show the effects of UT-based filtering via simulation considering practical tactical object tracking scenario.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.603-605
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• 1997

A new algorithm using 1-dimensional wavelet transform for autofocusing of optical instrument has been developed. Previous studies based on the conventional frequency analysis have shown that as the lens-object distance approaches the optimum value, the high frequency energy in the corresponding image shows a consistent increase. However, as conventional frequency analysis techniques hide spatial distribution of each band energy, shape information in the original signal cannot be easily utilized. In this paper, a newly devised wavelet based focus measuring scheme is presented. Unlike other frequency domain analysis techniques that simply produce "frequency-only" spectra, wavelet analysis provides a "time-frequency" localized view of a given signal. As a result, both frequency band filtering and spatial distribution filtering can easily be realized. Depending on the proposed focus quality measuring algorithm, a fast and reliable automatic focus adjustment of optical devices could be implemented.

• Journal of the Korea Society of Computer and Information
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• v.21 no.11
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• pp.23-30
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• 2016

In this paper, we propose an adaptive histogram projection technique for dynamic range compression and an efficient detail enhancement method which is enhancing strong edge while reducing noise. First, The high dynamic range image is divided into low-pass component and high-pass component by applying 'guided image filtering'. After applying 'guided filter' to high dynamic range image, second, the low-pass component of the image is compressed into 8-bit with the adaptive histogram projection technique which is using global standard deviation value of whole image. Third, the high-pass component of the image adaptively reduces noise and intensifies the strong edges using standard deviation value in local path of the guided filter. Lastly, the monitor display image is summed up with the compressed low-pass component and the edge-intensified high-pass component. At the end of this paper, the experimental result show that the suggested technique can be applied properly to the IR images of various scenes.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.4
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• pp.482-490
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• 2017

The radar signal processing procedure is divided into the pre-processing such as frequency down converting, down sampling, pulse compression, and etc, and the post-processing such as doppler filtering, extracting target information, detecting, tracking, and etc. The former is generally designed using FPGA because the procedure is relatively simple even though there are large amounts of ADC data to organize very quickly. On the other hand, in general, the latter is parallel processed by multiple DSPs because of complexity, flexibility and real-time processing. This paper presents the radar signal processor design using FPGA which includes not only the pre-processing but also the post-processing such as doppler filtering, bore-sight error, NCI(Non-Coherent Integration), CFAR(Constant False Alarm Rate) and etc.

• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.379-396
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• 2018

Purpose: The purpose of this study was to propose a standard form of noise filter drawing, which is widely used in the field of weapon systems, to define the essential specification which is not standardized at the existing drawings and to employ the reference for manufacturing and qualification test. Methods: To do that, it identifies the improvements to analyze 19 noise filter drawings, studies the principle of noise filtering to find the essential part of the spec. and reviews the MIL-STD-220C and KS IEC 60939, which is the widely used as a formal spec. pertaining to the noise filter. Throughout the study, a standard form is developed to standardize the attenuation characteristics and find eight crucial metrics to specify the noise filter. Results: The results of this study are as follows; The standardized drawings can be used as the qualification test of the item and the manufacturing and engineering documents to make the noise filter, which are also applicable to the reference document to review KDS(Korea Defense Standard) drawings.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06c
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• pp.68-73
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• 2008

전자 메일의 사용이 급증함에 따라 스팸메일의 양도 함께 증가하고 있다. 증가되는 스팸으로 인한 피해를 줄이기 위하여 여러 가지 기법들이 사용되고 있지만, 지능화되어가는 스패머들의 기술에 완전한 스팸메일의 차단은 불가능하며, 수신된 메일에 대해 사용자는 자신만의 기준으로 스팸메일 여부를 판단하고 있다. 본 논문에서는 스팸메일임에도 불구하고 수신되는 메일(FN)에 대해, 사용자의 반응 패턴을 통하여 이를 판단하고자 한다. 수신된 메일의 송신자와 제목, 보관 편지함 등에서 형태소 추출을 하고 이를 PN_DB(Positive형태소와 Negative형태소로 구성된 DB, 이하 PN_DB)로 구축한 뒤, Negative 형태소들을 Balcklist로 사용하여 FN 메일을 판단한다. FN 메일로 판단된 경우에 PN_DB에서 계산된 각각의 가중치 값을 적용하여 사용자의 과거 스팸 판단 성향이 반영된 FN_value를 시각적으로 표현함으로써 사용자의 판단을 용이하게 하는 시스템을 제안한다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.290-291
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• 2007

Barometers can provide height information steady but its accuracy becomes poor as the air data varies due to the vehicles's moving or time's elapsing. In order to keep the accuracy in spite of the air data changes, we propose a filter for the identification of baro-errors. The baro-errors mainly consist of bias and scale factor errors which gradually varies as the air data varies. With GPS height measurements, the scale factor and bias estimator is designed by applying the interacting multiple model (IMM) filtering technique to the baro-error random walk model. The resultant estimates are used to compensate current baro-measurement to supply accurate measurements steadily.

• International journal of advanced smart convergence
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• v.10 no.3
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• pp.163-171
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• 2021

Recently, Machine Learning-based visualization approaches have been proposed to combat the problem of malware detection. Unfortunately, these techniques are exposed to Adversarial examples. Adversarial examples are noises which can deceive the deep learning based malware detection network such that the malware becomes unrecognizable. To address the shortcomings of these approaches, we present Block-matching and 3D filtering (BM3D) algorithm and deep image prior based denoising technique to defend against adversarial examples on visualization-based malware detection systems. The BM3D based denoising method eliminates most of the adversarial noise. After that the deep image prior based denoising removes the remaining subtle noise. Experimental results on the MS BIG malware dataset and benign samples show that the proposed denoising based defense recovers the performance of the adversarial attacked CNN model for malware detection to some extent.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.468-473
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• 1993

Augmented proportional navigation requires the information of a target acceleration, which must be estimated by a filtering logic. The process necessary accompanies a time lag, which degrades the guidance performance. A trade-off study between augmented and conventional proportional navigation is conducted with the time lag taken into consideration. The result shows that the conventional proportional navigation has better performance against a target maneuver in the missile-target coplane, while the augmented has better performance against out-of-coplane maneuver.

• Proceedings of the Korea Society for Simulation Conference
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• 1999.04a
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• pp.32-36
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• 1999

본 연구에서는 대공 무기체계의 성능평가를 위한 시뮬레이션 모델의 개발로서 능력추정을 위한 수식의 전개와 전산프로그램을 개발하고 예제를 통하여 능력산출 예를 보였다. 본 연구에서 고려된 시뮬레이션 방법으로 Mon Carlo 시뮬레이션과 Karman Filtering을 사용하였다. 본 모델의 주요 단계로서 1) 가장 최단 경로에서의 표적과 탄두간의 상대 속도와 위치를 결정하고, 2) 표적의 탄두에 대한 취약면적을 산출하고 3) 마지막으로 표적살상 확률을 산정하는 과정의 단계에 따라 개발되었다.