• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2008.04a
• /
• pp.490-494
• /
• 2008

U-Channel Bridge is effective bridge type, because its edge beam performs role of barrier and enables to reduce additional dead loads. Although it is effective to reduce additional dead loads, there is possibility of bridge collapse under impact load due to car crash. Also, edge beam must have ability to induce safe driving and prevent falling accidents. Therefore, it requires behavior analysis and property investigation through the vehicle impact crashing edge beam. This study presents method of structural analysis of U-channel bridge and investigates design specifications for the effect of the edge beam under the vehicle impact. Also, it carries out stability investigation of behavior of edge beam and slab, based on Korean Highway Bridge Design Specifications and AASHTO LRFD Bridge Design Specification.

• Journal of Computational Design and Engineering
• /
• v.3 no.3
• /
• pp.191-197
• /
• 2016

Since 3D measurement technologies have been widely used in manufacturing industries edge detection in a depth image plays an important role in computer vision applications. In this paper, we have proposed an edge detection process in a depth image based on the image based smoothing and morphological operations. In this method we have used the principle of Median filtering, which has a renowned feature for edge preservation properties. The edge detection was done based on Canny Edge detection principle and was improvised with morphological operations, which are represented as combinations of erosion and dilation. Later, we compared our results with some existing methods and exhibited that this method produced better results. However, this method works in multiframe applications with effective framerates. Thus this technique will aid to detect edges robustly from depth images and contribute to promote applications in depth images such as object detection, object segmentation, etc.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.3
• /
• pp.584-590
• /
• 1994

A theoretical model has been developed to analyze the jet-edge interaction and the sound radiation. The edge responding to the sinuous impinging jet is regarded as an array of dipoles and their strength is determined by the boundary condition on the edge surface. The surface pressure distribution and the edgeforce are estimated using these dipoles. Then the pressure amplitude and directivity of the sound field is obtained by summing the radiating sounds from the dipole sources. It is found that the effective source is located a little distance downstream from the edge tip. And the directivity of the sound radiation is cardioid pattern near the edge but dipole pattern far from the edge. The theoretical model is confirmed by comparing the theoretical prediction of the edgeforce and sound pressure level with available experimental data.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.4
• /
• pp.111-123
• /
• 1996

In this paper, a new edge-based segmentation algorithm for range image using pseudo reflectance images (PRIs) is proposed. A model of pseudo reflectance which is useful in analyzing three dimensional scene and objects is introduced and then three PRIs are generated by the model. For generating three PRIs, bels and jain's differential window operator is selected and three different light source directions are determined. Three edge images are extracted from each PRI and a fused (logical ORing) edge image is constructed for the benefit of enhanced edge formation. The final segmentation results of the proposed algoritm are obtained after the processing of thinning, labeling and correcting erroeneous regions with the fused edge image. The good performance of edge detection and segmentation is confirmed via computer simulation with synthetic and real range images.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.6 s.38
• /
• pp.17-26
• /
• 2005

In this paper we propose three nonparametric tests such as Wilcoxon test, Median test and Van der Waerden test, based on linear rank statistics for detecting edges in images. The methods used herein are based on detecting changes in gray-levels obtained using an edge-height parameter between two sub-regions in a 5$\times$5 window We compare and analysis the performance of three statistical edge detectors in terms of qualitative measures with the edge maps and objective, quantitative measures.

• 유체기계공업학회:학술대회논문집
• /
• 2002.12a
• /
• pp.116-122
• /
• 2002

It is addressed that the turbulent broadband sound power from a sirocco fan can be modeled by the trailing edge noise. The trailing edge noise is usually influenced by inflow turbulenca separation, and boundary layer thickness on the blade. The design parameters such as solidity (c/s) and stagger angle are specified to predict performance and noise level because the separation and slip velocity are strongly affected by them along with the flow coefficient. This paper reports the effects of the stagger angle upon the trailing edge noise for various trailing edge shapes. It is believed that the serrated trailing edge provides break-up mechanism for organized convecting vortices, thereby reduce the overall noise level for every case of stagger angle.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.15 no.11
• /
• pp.1062-1068
• /
• 2004

In the frequency range where the magnetostatic surface wave may be excited, the edge singularity of a microstrip line having a farrite layer is calculated by using the method proposed by Meixner. From the calculated edge singularity, the change of the current distribution near the edge to which the magnetostatic surface wave propagates is steeper than that near the other edge. And the edge conditions vary with frequency. These results agree with the previous numerical results.

• Journal of computational fluids engineering
• /
• v.19 no.4
• /
• pp.94-99
• /
• 2014

The aerodynamic performance of a modified NACA64-418 with blunt trailing edges of irregular shape was investigated. As the trailing edge of the airfoil was thickened, the drag of the airfoil was increased due to development of a re-circulation bubble in the wake region. To reduce the drag of the airfoil with a blunt trailing edge, the optimum shape of the trailing edge for a modified NACA64-418 was investigated. The numerical results showed that the drag of the protruding shape was much more decreased than that of the retreating shape, but the lift was almost the same regardless of shape. In addition, the pitching moment of the modified NACA64-418 with a protruding sharp trailing edge was the smallest at the given angle of attack.

• Journal of Sensor Science and Technology
• /
• v.27 no.3
• /
• pp.143-149
• /
• 2018

In this paper, we introduce an edge-spike modulation method for visible light communication (VLC). This method is effective in preventing LED flicker and 120 Hz noise interference in base-band VLC. In the VLC transmitter, edge-spikes are generated by passing the digital data through a simple RC-high pass filter (HPF). The LED modulation of the edge-spikes does not change the average power of the LED light; thus it prevents LED flicker. In the VLC receiver, the 120 Hz noise from other lighting lamps is easily eliminated by RC-HPF, while the edge-spike signal is detected normally. In our experiment, the message of an air-quality sensor was successfully transmitted using edge-spike modulation. This structure is useful in constructing, e.g., wireless gas monitoring sensor systems to warn and prevent harmful gas leakage accidents in buildings using LED light.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.10 no.1
• /
• pp.101-106
• /
• 2007

In this paper, we propose chain code based decision technique of edge orientation. Edge Information is one of the most important information for handling image signals, and is applied to various civilian and military area, such as image surveillance for military reconnaissance, restoration of noised image signal, fingerprint recognition, and so on. The conventional methods to find edge orientations exploit a certain size of mask which weights for a certain direction, so they showed limitations in the case of diagonal edges except 45 degrees. We find edge orientations using chain code. According to the experiments, the proposed method shows better performance than the conventional approaches. The exact edge orientations including diagonal directions are well found.