• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.10
• /
• pp.109-115
• /
• 2016

In this paper, In this paper, we use two methods to compare the slim speakers. That way, the diaphragm scan using laser and diaphragm photographed using a thermal imaging camera. Slim speaker has the structure of a flat plate type. Break-up mode by this characteristic is displayed in a larger size. Further, since the installation space is narrow, it has limited moving coil cooling. As a result, the break-up mode slim speakers, a significant impact on quality. In this study, try to connect the break-up mode of the diaphragm, the heat transfer mode of the diaphragm. Experiment for comparison, a two-step. The first step is to measure the divided vibration through the vibration plate scan. The second step measures the diaphragm photographed using a thermal imaging camera. Then, compare the results of both of the same frequency. Thus, comparing the heat transfer pattern and the pattern of break-up mode. Tend to be analysis of break-up mode from the pattern comparison, and document for the optimum design.

• Computational Structural Engineering
• /
• v.8 no.3
• /
• pp.79-89
• /
• 1995

Two-element plate concept is incorporated into the buckling problem in order to simplify the nonlinear distribution of stress through the thickness of plate. Finite element formulations and programs based upon the Reissner functional and the modified Reissner functional using two-element plate concept are developed for buckling analysis of plates under axial compression. The two programs have been applied to obtain the linear elastic buckling behavior of axially compressed flat plates. Excellent agreement of linear elastic-solution results with exact or approximate solutions of other authors for the same boundary conditions proves the validity of the finite element method using two-element plate theory.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10b
• /
• pp.416-418
• /
• 2000

본 논문에서는 컴퓨터 비전의 한 분야인 영상처리에 의한 물체인식을 위한 선행연구로써, 차량번호판 인식 시스템을 구현하기 위한 연구의 한 부분인 차량 번호판의 일련번호부분을 추출하는 방법을 기술한다. 이진화된 전체 차량 이미지의 일련번호영역을 추출하기 위해 레이블링기법과 번호판 일련번호의 특성 등 선행지식을 이용하여 번호판의 각 일련번호를 찾아서 분할하고 추출하는 알고리즘을 제안한다. 번호판영역을 찾는 동시에 분할하고 추출해 줌으로써 복잡한 여러 알고리즘을 사용하지 않고도 비교적 정확히 번호판의 일련번호를 추출할 수 있고, 속도면에서도 상당히 우수한 결과를 보여준다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.4
• /
• pp.333-336
• /
• 2017

A speaker diaphragm generates a divided vibration. The influence of the break-up mode is sufficient to cause a shape change in the diaphragm. In this paper, is widely used in ultra-thin multi-media devices, including smart phones is the advance guard of the IT sector, the micro-speakers and its target. Micro-speakers are different from general speakers. The plate has structural form and space constraints. In particular, they utilize a closed-type drive space. It is difficult to provide cooling for the auxiliary suspension structure because of the heat generated in the moving coil. The present study considered the relationship between the break-up mode and the heat transfer of the diaphragm. An experiment was conducted in two stages to compare the embodiment of the break-up mode and heat transfer in a certain frequency range. The changes in the heat were determined through measurements and thermal imaging of the break-up mode. The break-up mode tendency of the diaphragm could be rapidly predicted based on the imaging results using the thermal imaging camera. This will help in the optimal design of micro-speakers.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.5
• /
• pp.125-134
• /
• 2004

This paper proposes a method for recognition of traffic signs using wavelet transform and shape information from the segmented traffic sign regions. It first segments traffic sign candidate regions by connected component algorithm from binary images, obtained by utilizing the RGB color ratio of each pixel in the image, and then extracts actual traffic sign regions based on their symmetries on X- and Y-axes. In the recognition stage, it utilizes shape information including moment edge correlogram and the number of crossings which concentric circular patterns from region center intersects with frequency information extracted by wavelet transform It finally performs recognition by measuring similarity with the templates in the database. The experimental results show the validity of the proposed method from geometric transformations and environmental factors.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2003.05b
• /
• pp.635-640
• /
• 2003

본 논문에서는 일본 차량 번호판 인식에 적응적 탬플릿 마스킹 방법을 이용하여 번호판 문자, 숫자를 분할하고 패턴벡터기법을 이용하여 인식하는 방법을 제안하였다 주, 야간과 거리에 따른 일본 차량 번호판 영상을 입력받아 전처리 과정을 수행한 후 에지 정보와 명도값 변화의 빈도수를 이용하여 번호판 영역을 검출하였다 검출된 번호판 영역에서 각 문자 및 숫자의 위치정보와 적응적 탬플릿을 이용하여 분할하고 번호판의 지역문자를 무게중심 패턴으로 분류 한 다음 크기와 이동에 무관한 특실을 가지는 패턴 벡터를 적용하여 문자를 인식하였으며, 숫자는 Four Segment Pattern을 이용하여 인식하도록 하였다 본 논문에서 제안한 방법을 실제 일관 차량 번호판 인식에 적용한 결과 98.8％ 추출율과 96.6％의 인식율을 나타내었다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.12 no.1
• /
• pp.1-8
• /
• 1992

A method analizing contact pressure between plate and elastic half space is presented by using F.E.M. With the method, the pressure intensities at surface nodes of half space cae be directly calculated by using flexibility matrix of half space. The method is originally presented by Y.K. Cheung et al.(3) Insted of Y.K. Cheung's method, which use a conception of equi-contact pressure area around each surface nodes of half space in the noded rectanqular element area. We use the equi-contact pressure area around the Gaussian integration points of half space surface in the noded isoparametric element area. Numarical examples are presented and compared with other's studies.

• Journal of the Korea Convergence Society
• /
• v.12 no.1
• /
• pp.29-35
• /
• 2021

License plate recognition plays a key role in intelligent transportation systems. Therefore, it is a very important process to efficiently detect the number and character areas. In this paper, we propose a method to effectively detect license plate number area by applying deep learning and semantic image segmentation algorithm. The proposed method is an algorithm that detects number and text areas directly from the license plate without preprocessing such as pixel projection. The license plate image was acquired from a fixed camera installed on the road, and was used in various real situations taking into account both weather and lighting changes. The input images was normalized to reduce the color change, and the deep learning neural networks used in the experiment were Vgg16, Vgg19, ResNet18, and ResNet50. To examine the performance of the proposed method, we experimented with 500 license plate images. 300 sheets were used for learning and 200 sheets were used for testing. As a result of computer simulation, it was the best when using ResNet50, and 95.77% accuracy was obtained.

• Proceedings of the Korean Information Science Society Conference
• /
• 1999.10b
• /
• pp.524-526
• /
• 1999

본 논문은 환경에 독립적인 자동차 영상에서 자동차 번호판 영역을 추출하는 방법을 제안하고 실험 결과를 기술한다. 번호판 주위환경에는 다양한 조건이 존재하며 이에 적응성을 가지고 빠른 추출을 수행하는 것은 매우 중요한 문제이다. 본 논문은 이러한 문제를 해결하기 위해 HSI 컬러 모델에 기반하여 번호판을 면밀히 분석하여 번호판을 유형별로 그룹화하고, 지역 분할 및 병합을 통해 빠른 시간안에 번호판 후보 영역을 검색한다. 그리고 번호판이 갖는 특성을 이용하여 후보 영역에서 번호판 영역임을 검증함으로써 자동차 번호판 영역을 찾는다.

• KIPS Transactions on Software and Data Engineering
• /
• v.3 no.9
• /
• pp.361-368
• /
• 2014

The LPR(License plate recognition) system has been developed to efficient control for complex traffic environment and currently be used in many places. However, because of light, noise, background changes, environmental changes, damaged plate, it only works limited environment, so it is difficult to use in real-time. This paper presents a heuristic segmentation algorithm for robust to noise and illumination changes and introduce a real-time license plate recognition system using it. In first step, We detect the plate utilized Haar-like feature and Adaboost. This method is possible to rapid detection used integral image and cascade structure. Second step, we determine the type of license plate with adaptive histogram equalization, bilateral filtering for denoise and segment accurate character based on adaptive threshold, pixel projection and associated with the prior knowledge. The last step is character recognition that used histogram of oriented gradients (HOG) and multi-layer perceptron(MLP) for number recognition and support vector machine(SVM) for number and Korean character classifier respectively. The experimental results show license plate detection rate of 94.29%, license plate false alarm rate of 2.94%. In character segmentation method, character hit rate is 97.23% and character false alarm rate is 1.37%. And in character recognition, the average character recognition rate is 98.38%. Total average running time in our proposed method is 140ms. It is possible to be real-time system with efficiency and robustness.