• Title/Summary/Keyword: 줄무늬 패턴

Search Result 21, Processing Time 0.035 seconds

Influence of the Shear Property of Seabed Appearing in the Striation Pattern of the Spectrogram of Ship-radiated Noise Measured in a Shallow Sea (천해에서 측정한 선박 방사소음 스펙트로그램의 줄무늬 패턴에 나타나는 해저면 전단성 영향)

  • Lee, Seong-Wook;Hahn, Joo-Young;Baek, Woon;Na, Jung-Yul
    • The Journal of the Acoustical Society of Korea
    • /
    • v.23 no.3
    • /
    • pp.197-205
    • /
    • 2004
  • This paper represents the results of interpretation on the cause of sign changing of the striation slopes appearing in the range-frequency domain spectrogram of ship-radiated noise measured in a shallow sea. Striation patterns and dispersion characteristics simulated from a numerical model based on mode theory at various seabed conditions show that the sign changing of the striation slopes appearing in measured signal is caused by the shear property of seabed. more specifically by the shear property of the basement lying below the sediment which is estimated about 3±1m thick.

A Euclidean Reconstruction of 3D Face Data Using a One-Shot Absolutely Coded Pattern (단일 투사 절대 코드 패턴을 이용한 3차원 얼굴 데이터의 유클리디안 복원)

  • Kim, Byoung-Woo;Yu, Sun-Jin;Lee, Sang-Youn
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.42 no.6
    • /
    • pp.133-140
    • /
    • 2005
  • This paper presents a rapid face shape acquisition system. The system is composed of two cameras and one projector. The technique works by projecting a pattern on the object and capturing two images with two cameras. We use a 'one shot' system which provides 3D data acquired by single image per camera. The system is good for rapid data acquisition as our purpose. We use the 'absolutely coded pattern' using the hue and saturation of pattern lines. In this 'absolutely coded pattern' all patterns have absolute identification numbers. We solve the correspondence problem between the two images by using epipolar geometry and absolute identification numbers. In comparison to the 'relatively coded pattern' which uses relative identification numbers, the 'absolutely coded pattern' helps obtain rapid 3D data by one to one point matching on an epipolar line. Because we use two cameras, we obtain two images which have similar hue and saturation. This enables us to have the same absolute identification numbers in both images, and we can use the absolutely coded pattern for solving the correspondence problem. The proposed technique is applied to face data and the total time for shape acquisition is estimated.

Stripe-geometry 2D Gratings for High-Efficiency Array Spot Generation (고효율 스폿 배열 발생을 위한 줄무늬형 2차원 회절격자)

  • Lee, Deug-Ju;Yoon, Byeong-Ho;Kim, Nam;Suh, Ho-Hyung
    • Korean Journal of Optics and Photonics
    • /
    • v.6 no.2
    • /
    • pp.108-114
    • /
    • 1995
  • 규칙적인 간격이 $M\timesN$ 이차원패턴과 임의 모양 빔 스폿을 발생시키기 위해 일반적인 이차원 Dammann 격자보다 재구성 에러가 작고, 높은 효율을 보이는 줄무늬형 격자를 설계하였다. 회절효율은 일반적인 이차원 Dammann 격자의 효율보다 평균 15-20% 정도 높은 60% 이상을 얻었다. 설계된 격자는 컴퓨터 시뮬레이션을 통해 회절특성을 확인하였으며 우수한 패턴 발생 결과가 확인되었다. $3\times3에서 11\times11$까지의 규칙적인 스폿 배열과 문자열에 대한 효율, 계산 시간 및 표준편차를 비교분석하였다.

  • PDF

User-friendly 3D Object Reconstruction Method based on Structured Light in Ubiquitous Environments (유비쿼터스 환경에서 구조광 기반 사용자 친화적 3차원 객체 재구성 기법)

  • Jung, Sei-Hwa;Lee, Jeongjin
    • The Journal of the Korea Contents Association
    • /
    • v.13 no.11
    • /
    • pp.523-532
    • /
    • 2013
  • Since conventional methods for the reconstruction of 3D objects used a number of cameras or pictures, they required specific hardwares or they were sensitive to the photography environment with a lot of processing time. In this paper, we propose a 3D object reconstruction method using one photograph based on structured light in ubiquitous environments. We use color pattern of the conventional method for structured light. In this paper, we propose a novel pipeline consisting of various image processing techniques for line pattern extraction and matching, which are very important for the performance of the object reconstruction. And we propose the optimal cost function for the pattern matching. Using our method, it is possible to reconstruct a 3D object with efficient computation and easy setting in ubiquitous or mobile environments, for example, a smartphone with a subminiature projector like Galaxy Beam.

Underwater Target Localization Using the Interference Pattern of Broadband Spectrogram Estimated by Three Sensors (3개 센서의 광대역 신호 스펙트로그램에 나타나는 간섭패턴을 이용한 수중 표적의 위치 추정)

  • Kim, Se-Young;Chun, Seung-Yong;Kim, Ki-Man
    • The Journal of the Acoustical Society of Korea
    • /
    • v.26 no.4
    • /
    • pp.173-181
    • /
    • 2007
  • In this paper, we propose a moving target localization algorithm using acoustic spectrograms. A time-versus-frequency spectrogram provide a information of trajectory of the moving target in underwater. For a source at sufficiently long range from a receiver, broadband striation patterns seen in spectrogram represents the mutual interference between modes which reflected by surface and bottom. The slope of the maximum intensity striation is influenced by waveguide invariant parameter ${\beta}$ and distance between target and sensor. When more than two sensors are applied to measure the moving ship-radited noise, the slope and frequency of the maximum intensity striation are depend on distance between target and receiver. We assumed two sensors to fixed point then form a circle of apollonios which set of all points whose distances from two fixed points are in a constant ratio. In case of three sensors are applied, two circle form an intersection point so coordinates of this point can be estimated as a position of target. To evaluates a performance of the proposed localization algorithm, simulation is performed using acoustic propagation program.

Vertical Stripes Extraction By Using The Gabor Filter for 3D Face Acquisition (3차원 얼굴정보 획득을 위한 가버필터를 이용한 세로줄무늬 패턴 추출)

  • 김인범;김재희
    • Proceedings of the IEEK Conference
    • /
    • 2002.06d
    • /
    • pp.133-136
    • /
    • 2002
  • In this paper, we propose a method to extract vertical stripes projected on human face using Gabor filter, Previous work cannot extract continuous vertical stripes in the eye and mouth region due to their horizontal lines, Proposed method use Gator filter adaptively according to main frequencies and directions of stripes in each block. Experimental results show that Proposed method can extract continuous vertical stripes in the eye and mouth region

  • PDF

Application of the artificial intelligence for automatic detection of shipping noise in shallow-water (천해역 선박 소음 자동 탐지를 위한 인공지능 기법 적용)

  • Kim, Sunhyo;Jung, Seom-Kyu;Kang, Donhyug;Kim, Mira;Cho, Sungho
    • The Journal of the Acoustical Society of Korea
    • /
    • v.39 no.4
    • /
    • pp.279-285
    • /
    • 2020
  • The study on the temporal and spatial monitoring of passing vessels is important in terms of protection and management the marine ecosystem in the coastal area. In this paper, we propose the automatic detection technique of passing vessel by utilizing an artificial intelligence technology and broadband striation patterns which are characteristic of broadband noise radiated by passing vessel. Acoustic measurements to collect underwater noise spectrum images and ship navigation information were conducted in the southern region of Jeju Island in South Korea for 12 days (2016.07.15-07.26). And the convolution neural network model is optimized through learning and validation processes based on the collected images. The automatic detection performance of passing vessel is evaluated by precision (0.936), recall (0.830), average precision (0.824), and accuracy (0.949). In conclusion, the possibility of the automatic detection technique of passing vessel is confirmed by using an artificial intelligence technology, and a future study is proposed from the results of this study.

Influence of the Geoacoustic Parameters of Seabed Appearing in the Broadband Interference Pattern by Moving Targets (이동 표적에 의한 광대역 간섭패턴의 지음향 인자 영향)

  • Hahn, Joo-Young;Lee, Hyeong-Uk;Lee, Bong-Ki
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.10 no.3
    • /
    • pp.43-50
    • /
    • 2007
  • A range-frequency interference pattern is analyzed in the course of the propagation of ship noise in shallow water. It has been shown to exhibit striated bands of intensity maxima and minima in the spectrogram. The slope of the striations is an invariant of the modal interference and is described by a waveguide invariant parameter $\beta$. It turns out that this interference pattern is useful for identifying the physical properties of the waveguide such as seabed properties. In this article, the interference pattern is analyzed using image processing techniques to produce the distribution of the beta and the effects of sediment types and geoacoustic parameters on beta distribution are examined and characterized by moments of the distributions.

High Resolution Depth-map Estimation in Real-time using Efficient Multi-threading (효율적인 멀티 쓰레딩을 이용한 고해상도 깊이지도의 실시간 획득)

  • Cho, Chil-Suk;Jun, Ji-In;Choo, Hyon-Gon;Park, Jong-Il
    • Journal of Broadcast Engineering
    • /
    • v.17 no.6
    • /
    • pp.945-953
    • /
    • 2012
  • A depth map can be obtained by projecting/capturing patterns of stripes using a projector-camera system and analyzing the geometric relationship between the projected patterns and the captured patterns. This is usually called structured light technique. In this paper, we propose a new multi-threading scheme for accelerating a conventional structured light technique. On CPUs and GPUs, multi-threading can be implemented by using OpenMP and CUDA, respectively. However, the problem is that their performance changes according to the computational conditions of partial processes of a structured light technique. In other words, OpenMP (using multiple CPUs) outperformed CUDA (using multiple GPUs) in partial processes such as pattern decoding and depth estimation. In contrast, CUDA outperformed OpenMP in partial processes such as rectification and pattern segmentation. Therefore, we carefully analyze the computational conditions where each outperforms the other and do use the better one in the related conditions. As a result, the proposed method can estimate a depth map in a speed of over 25 fps on $1280{\times}800$ images.