• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2000.04a
• /
• pp.171-174
• /
• 2000

In this paper, impact sound realization of composite structures is performed to investigate the possibility of a new NDE system - Tapping Sound Analysis (TSA). TSA detects the existence of damages inside the structures by comparing tapping sound with pre-computed sound data of healthy structures. Tapping on the structures is modeled as impact problem and solved using finite element method. Calculation of sound is formulated based on the coupled finite element and boundary element method. Numerical simulation of impact sound and feature extraction scheme show that the impact sound can be used in the identification of damages of laminated composites.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.39 no.2
• /
• pp.103-112
• /
• 1997

A CELTHYM(CEll-based Long-term HYdrologic Model), a pre-processor and a post-processor that can he integrated with geographic information system(GIS) were developed to predict the stream flow of a small agricultural watershed. Three kinds of routines, that are watershed boundary extraction routine(WBER), curve number calculation routine(CNR) and maximum available soil moisture calculation routine(MASR) composed pre-processor that was nicely interfaced with CELTRYM and GIS. Two kinds of routines, grapher and map composer composed post-processor that was well adapted CELTHYM output to chart making and GIS map making. The developed pre-post processor was useful for the GIS integration and spatial comprehension of the CELTHYM output.

• Journal of information and communication convergence engineering
• /
• v.9 no.2
• /
• pp.207-211
• /
• 2011

This paper presents a method for facial feature representation and recognition from the Covariance Matrices of the Gabor-filtered images. Gabor filters are a very powerful tool for processing images that respond to different local orientations and wave numbers around points of interest, especially on the local features on the face. This is a very unique attribute needed to extract special features around the facial components like eyebrows, eyes, mouth and nose. The Covariance matrices computed on Gabor filtered faces are adopted as the feature representation for face recognition. Geodesic distance measure is used as a matching measure and is preferred for its global consistency over other methods. Geodesic measure takes into consideration the position of the data points in addition to the geometric structure of given face images. The proposed method is invariant and robust under rotation, pose, or boundary distortion. Tests run on random images and also on publicly available JAFFE and FRAV3D face recognition databases provide impressively high percentage of recognition.

• Journal of Biomedical Engineering Research
• /
• v.10 no.3
• /
• pp.331-342
• /
• 1989

This paper presents a new algorithm that extracts lung region in X-Rays and enhance.j the region. Comparing to prior algorithms that enhance whole X-Ray image, this algorithm leads more effective results. For this algorithm extracts lung region first, and enhances the lung region excluding parameters of other region. For choosing optimal threshold, we compare OTSU's mothod with the proposed method. We obtain lung boundary using contour following algorithm and Rray level searching method in gray level rescaled image. We Process histogram equalization in lung region and obtain enhanced lung image. By using the proposed algorithm, we obtain lung region effectively in chest X-Ray that need in medical image diagnostic system.

• Solar Energy
• /
• v.10 no.1
• /
• pp.38-46
• /
• 1990

For the optimal design and the efficient operation of the double pipe type latent heat storage equipment, the effect of the parameters of the system were analysed. The statistical analysis showed that the theoretical and the experimental results of the volume change rate and the temperature variations were well agreed. Therefore, this theoretical model is reasonable to analyze two dimensional moving boundary problems. In the analysis of the effects of the parameters, the heat extraction fraction and the water outlet temperature of the system as function of the time were analysed depending on the initial temperature of PCM, water inlet temperature, water mass flow rate and the dimension of the inner tube.

• International Journal of CAD/CAM
• /
• v.6 no.1
• /
• pp.81-87
• /
• 2006

This paper describes a method for extracting surfaces from multi-material CT (Computed Tomography) data. Most contouring methods such as Marching Cubes algorithm assume that CT data are composed of only two materials. Some extended methods such as [3, 6] can extract surfaces from the multi-material (non-manifold) implicit representation. However, these methods are not directly applicable to CT data that are composed of three or more materials. There are two major problems that arise from fundamentals of CT. The first problem is that we have to use n(n-1)/2 threshold values for CT data contains n materials and select appropriately one threshold value for each boundary area. The second is that we cannot reconstruct only from CT data in which area three or more materials are adjacent each other. In this paper, we propose a method to solve the problems by using image analysis and demonstrate the effectiveness of the method with application examples construct polygon models from CT data of machine parts.

• Speech Sciences
• /
• v.8 no.4
• /
• pp.45-58
• /
• 2001

Modulated components of a speech signal are frequently used for speech coding, speech recognition, and speech synthesis. Time-frequency representation (TFR) reveals some information about instantaneous frequency, instantaneous bandwidth and boundary of each component of the considering speech signal. In many cases, the extraction of AM-FM components corresponding to instantaneous frequencies is difficult since the Fourier spectra of the components with time-varying instantaneous frequency are overlapped each other in Fourier frequency domain. In this paper, an efficient method decomposing speech signal into AM-FM components is proposed. A variable bandwidth filter is developed for the decomposition of speech signals with time-varying instantaneous frequencies. The variable bandwidth filter can extract AM-FM components of a speech signal whose TFRs are not overlapped in timefrequency domain. Also, amplitude and instantaneous frequency of the decomposed components are estimated by using Hilbert transform.

• ETRI Journal
• /
• v.39 no.5
• /
• pp.652-661
• /
• 2017

A mention has a noun or noun phrase as its head and constructs a chunk that defines any meaning, including a modifier. Mention detection refers to the extraction of mentions from a document. In mentions, coreference resolution refers to determining any mentions that have the same meaning. Pointer networks, which are models based on a recurrent neural network encoder-decoder, outputs a list of elements corresponding to an input sequence. In this paper, we propose mention detection using pointer networks. This approach can solve the problem of overlapped mention detection, which cannot be solved by a sequence labeling approach. The experimental results show that the performance of the proposed mention detection approach is F1 of 80.75%, which is 8% higher than rule-based mention detection, and the performance of the coreference resolution has a CoNLL F1 of 56.67% (mention boundary), which is 7.68% higher than coreference resolution using rule-based mention detection.

• Aerospace Engineering and Technology
• /
• v.10 no.2
• /
• pp.163-169
• /
• 2011

This paper introduces a method about water line detection using SAR image. The method includes pre-processing of the SAR image with the threshold of the histogram to recognize the boundary between the water and the landmass area. Finally we applied the image differentiation to detect the water line in the SAR image. The TerraSAR-X and the Cosmo-SkyMed images, which are the high spatial resolution X-band SAR data, are used for the evaluation of our algorithm. The accuracy is verified over the stream line in urban area with the result from the Cosmo-SkyMed.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.05a
• /
• pp.615-618
• /
• 2003

본 논문에서는 컨베이어 벨트상에서 이송되는 대용량 소포영상의 획득과정을 통해 ROI(Region of Interest) 고속추출하기 위한 방법 중에서 소포의 면적을 산출하기 위한 외형 좌표값을 산출하는 방법을 제시한 것이다. 이송하는 과정에서 높이센서의 값과 투입되는 각도에 따라 최장길이가 다르지만 이 값도 산출이 용이하다 이와 같은 정보와 결합하여 소포의 부피를 산출을 위해 사용될 수 있는 소포의 외형 좌표값들의 산출 방법과 활용방법을 제시한 것이다. 초기과정에는 불필요한 영역을 검사하기 위한 조건과 유사한 패턴을 단계적으로 제거하는 방법을 적용하였다. $4,096{\times}4,096$ 이상의 대용량 영상에서 불필요한 영역 제거 시간을 포함하여 평균 30.85msec 이내에 추출이 가능한 방법을 제시한 것이다.