• 전기전자학회논문지
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• 제24권4호
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• pp.1034-1038
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• 2020

레이더를 통한 표적식별을 효과적으로 처리하기 위해서는 표적에 대한 정확한 신호 정보가 필요하다. 그러나 이러한 표적 신호에는 잡음이 섞여 있는 경우가 일반적이며, 이 부분에 대한 연구가 지속적으로 이루어지고 있다. 특히 표적에 대한 이미지 처리, 표적신호처리, 표적식별 등이 그 예라 할 수 있겠다. 군사적 측면으로 볼 때 표적식별 분야가 중요하므로 본 논문에서는 트리 구조의 퍼지 뉴럴 네트워크를 이용하여 비행체 표적식별에 대한 연구를 수행하였다. 비행체에 대한 반사파 데이터를 활용하여 퍼지 뉴럴 네트워크를 학습시켜 모델에 대한 최적화를 수행하였고, 최적화된 모델에 표적에 대한 테스팅 데이터를 입력하여 표적식별에 대한 실험을 수행하여 그 결과를 통해 제안된 방법의 효용성을 검증하였다.

• 한국전자파학회논문지
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• 제28권10호
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• pp.810-818
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• 2017

본 논문에서는 근거리 미사일/로켓 방어시스템의 대응탄용 근접센서에 적용되는 칼만필터 기반 지면밀착 접근표적 추적기법을 제안한다. 탄의 전면에 위치한 근접센서는 지면 클러터를 최소화하기 위한 안테나의 제한된 빔폭으로 인해 위협체가 파편 분산 범위에 들어오는 순간을 감지하기 쉽지 않다. 또한 복잡한 지상 환경에서는 위협체뿐만 아니라, 바위, 나무 등과 같은 클러터 정보를 포함하여 정확한 위협체 감지에 어려움이 따른다. 이를 해결하기 위해 본 연구에서는 칼만필터 기반의 접근표적 추적기법을 제시하고, 추적성능 향상을 위한 잡음 공분산 행렬의 새로운 추정 방식을 적용한다. 이후 제안한 잡음 공분산 행렬을 적용한 칼만필터의 우수한 추적 성능을 발사시험 결과를 통해 제시하여 연구의 타당성을 검증한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.194-202
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• 2009

The paper deals with the countermeasure against structure-borne noise source and noise reduction of drainage pipes. Recently, the problem the problem of the toilet drain noise of an apartment house has been become the center of public interest and a target of public grievance. Generally, the drain noise of a toilet in the apartment house has a pink noise characteristics below 2 kHz level, and therefore, the structure-borne noise has a great effect on the entire drain noise. In order to measure the transmission loss for various kinds of pipes such as PVC pipes, cast-iron pipes and newly developed AS pipes, experimental setup containing speakers as a sound source was designed and manufactured. The second-stories measurement room with a small size anechoic chamber was constructed and the noise level for different kinds of drainage pipes was measured by the sound level meter. Through the experimental research in the study, noise reduction capacity for various kinds of drainage pipes and countermeasures against structure-borne noise source are demonstrated.

• 대한기계학회논문집A
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• 제39권4호
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• pp.437-445
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• 2015

유체는 잘 통과시키면서 소음을 줄일 수 있는 다공성 패널을 설계하는 방법을 제시한다. 주된 아이디어는 1/4 파장관을 다공성 패널의 구멍들 주위에 배열하는 것이다. 먼저, 구멍이 하나만 있는 단위모델에 대한 다양한 사례 연구를 수행한다. 패널의 두께를 증가시키지 않기 위해, 단위 모델을 수직 방향으로 세 개층으로 분할하고, 가운데 분할층을 설계 영역으로 선정한다. 투과 손실 곡선 상에서 목표투과 손실 값을 상회하는 주파수 대역이 가능한 넓도록 1/4 파장관의 개수와 배열을 결정한다. 이렇게 최적 설계된 단위 모델을 다공성 패널에 주기적으로 배열하여 설계 목적을 달성하였다. 제시된 방법은 특정 목표 주파수와 목표 투과 손실 값에 대해 전개되었지만, 다양한 목표값에 적용 가능하다.

• 말소리와 음성과학
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• 제4권3호
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• pp.103-110
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• 2012

In this paper, a target signal detection method using multiple signal classification (MUSIC) algorithm is proposed. The MUSIC algorithm is a subspace-based direction of arrival (DOA) estimation method. Using the inverse of the eigenvalue-weighted eigen spectra, the algorithm detects the DOAs of multiple sources. To apply the algorithm in target signal detection for GSC-based beamforming, we utilize its spectral response for the DOA of the target source in noisy conditions. The performance of the proposed target signal detection method is compared with those of the normalized cross-correlation (NCC), the fixed beamforming, and the power ratio method. Experimental results show that the proposed algorithm significantly outperforms the conventional ones in receiver operating characteristics (ROC) curves.

• 제어로봇시스템학회논문지
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• 제13권11호
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• pp.1053-1059
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• 2007

This paper presents a target sate estimator(TSE) with low pass filter for improving the gun driving command. The ballistic computer uses target information such as predicted range, velocity, acceleration of a target to generate the gun command. We adopt the finite impulse response(FIR) filter as our TSE to shorten calculation time for the driving command and due to its inherent stability property. We also introduce a post-processing filter to reduce the high frequency components in the output signal of a TSE which may cause instability of gun driving. The first order low pass filter has been designed based on $H{\infty}$ criteria considering the noise characteristics. To show the validity of the present scheme, simulation results are given for the overall gun driving system including aircraft target information.

• 한국군사과학기술학회지
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• 제18권3호
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• pp.253-259
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• 2015

This paper introduces a signal processing technique for discrimination of missile target. In order to detect and discriminate the target, a seeker radar makes use of chirp waveform and stretch processing to generate high resolution range profiles(HRRPs). RELAX(relaxation) algorithm, which is one of the spectral estimation techniques, was used to find scattering centers of a missile from HRRP. From the information on the distribution of one-dimensional(1-D) scattering centers on a target, we can discriminate the target without noise.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권5호
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• pp.1711-1725
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• 2014

Multi-target tracking is the main purpose of many video surveillance applications. Recently, multi-target tracking based on the particle filter method has achieved robust results by using the data association process. However, this method requires many calculations and it is inadequate for real time applications, because the number of associations exponentially increases with the number of measurements and targets. In this paper, to reduce the computational cost of the data association process, we propose a novel multi-target tracking method that excludes particle samples in the overlapped predictive region between the target to track and marginal targets. Moreover, to resolve the occlusion problem, we define an occlusion mode with the normal dynamic mode. When the targets are occluded, the mode is switched to the occlusion mode and the samples are propagated by Gaussian noise without the sampling process of the particle filter. Experimental results demonstrate the robustness of the proposed multi-target tracking method even in occlusion.

• 한국군사과학기술학회지
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• 제6권3호
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• pp.36-43
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• 2003

Multi-target away signal simulator which can simulate the radiated noises of maneuvering targets in a specified ocean range is an essential equipment for the validation of developed towed array sonar system. This simulator should provide realistic multi-channel signals those are required for beamforming on the signal processing unit of towed away system. This paper describes the overall system configuration and signal synthesis techniques for the target radiated noise. And this paper considers why the time delays between target and individual sensors are caused and how to compensate these time delays to individual sensors output. This multi-purpose target simulator could be used for the training of TASS operators.

• 한국군사과학기술학회지
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• 제8권3호
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• pp.24-32
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• 2005

This paper describes the tracking filter performance for Naval Gun Ballistic Computation Unit(BCU). BCU needs tracing filter for gun firing. Using data of tracking sensor, BCU calculates the future position of Target and Gun order in the time of flight. In this paper, tracing filter is designed with interacting multiple model(IMM). The tracking algorithm based on the IMM requirers a considerable number of sub-model for the various maneuvering target in order to have a good performance. But, in the case of ship target, the maneuvering is restricted compared with the air target. Considering the maneuvering properties and adjusting the mode transition probabilities and the process noise of sub-model, We designed the IMM3 algorithm for Naval tracking filter with three sub-model.