• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.32 no.4_1
• /
• pp.363-371
• /
• 2014

Most space-borne optical scanning systems adopt linear arrayconfigurations. The well-knownthree different types of space-borne sensors arealong-track line scanner, across-track linescanner, and three line scanner. To acquire accurate location information of an object on the ground withthose sensors, the exterior and interior orientation parameters are critical factors for both of space-borne and airborne missions. Since the imaging geometry of sensors mightchange time to time due to thermal influence, vibration, and wind, it is very important to analyze the Interior Orientation Parameters (IOP) effects on the ground. The experiments based on synthetic datasets arecarried out while the focal length biases are changing. Also, both high and low altitudes of the imagingsensor were applied. In case with the along-track line scanner, the focal length bias caused errors along the scanline direction. In the other case with the across-track one, the focal length bias caused errors alongthe scan line and vertical directions. Lastly, vertical errors were observed in the case ofthree-line scanner. Those results from this study will be able to provide the guideline for developing new linearsensors, so as for improving the accuracy of laboratory or in-flight sensor calibrations.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2020.05a
• /
• pp.580-581
• /
• 2020

얼굴을 이용한 신원인식 방법은 높은 사용 편의성과 보편성 때문에 다양한 분야에서 활용되고 있다. 그러나 타인의 얼굴 사진이나 테블릿 PC 를 통한 얼굴 동영상 재생과 같은 손쉬운 방법을 통한 얼굴 스푸핑 공격 사례가 다수 보고되고 있다. 하지만 기존의 영상의 텍스처 특징을 활용한 방법은 영상의 초점 상태에 취약하고 기계학습에 사용된 데이터에 의존적이다. 따라서 보다 강력한 스푸핑 탐지 기술이 필요하다. 본 연구에서는 다양한 각도와 거리 편차 요소를 포함하는 자체 구축 DB 와 DenseNet 을 활용한 딥러닝 기반의 위조 얼굴 검출 기술을 연구했다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.35 no.6
• /
• pp.485-494
• /
• 2017

This study focuses on automatic image registration between multiple IR images using simple preprocessing method and modified local feature extraction algorithm. The input images were preprocessed by using the median and absolute value after histogram equalization, and it could be effectively applied to reduce the brightness difference value between images by applying the similarity of extracted features to the concept of angle instead of distance. The results were evaluated using visual and inverse RMSE methods. The features that could not be achieved by the existing local feature extraction technique showed high image matching reliability and application convenience. It is expected that this method can be used as one of the automatic registration methods between multi-sensor images under specific conditions.

• Archives of design research
• /
• v.12 no.4
• /
• pp.99-108
• /
• 1999

The interior space in a passenger car is consisted with many partial elements, and the instrument panel is the most important part from all of them, which is designate the total image of the interior design and the space variation, drivability and safety of the interior space. ] The instrument panel of a passenger car in the early age had the concept of a wall between the engine room and the passenger cabin on which the instrument for the driver were fitted. Therefore the central mounting of the instruments was the typical feature regardless of the position of a driver seat. As the automobiles became more functional with many equipments, driver oriented instrument panel with energy absorbing materials had been developed, and that was the beginning of the various instrument panel design of these days. The recent instrument panels of passenger car have the tendency of going back to the central instrument mounting as it was at the past on a few cars for the strict safety regulation, a new production technology and for the enhanced drivability. It can be summarized into a few results as these with the analysis of a few recent instrument panels. -minimizing the total volume for the better frontal visibility. -energy absorbing and passive structures for the strict impact regulations. -revival of central instrument mounting for the convenience and safety through minimizing the difference of the focal length of a driver.

• Journal of radiological science and technology
• /
• v.37 no.2
• /
• pp.93-100
• /
• 2014

Recently the development of portable digital wireless imaging system, which acquires digital radiation images by using wireless LAN telecommunications function in an easy and fast way, provides lots of convenience for people. Considering the characteristics of portable imaging tests on emergency and critical patients, this study aims to suggest guidelines for Digital wireless detector by evaluating the effect of de-centering of focus-grid and displacement of subject in detector on the quality of image. The equipments used for this study were Elmo-T6 Digital Mobile X-ray system (SIMAZU Corp.), el' Tor ($14{\times}17$ "Wireless detector), Grid (10:1) and Chest & head phantom. After acquiring post-processing image according to dose increase and de-centering image of grid-focus and head phantom displacement image, this study compared, analyzed and evaluated these images by using a digital image analysis program by Image J. In the change of images based on dose increase, images were rough in the dose of 0.5 mAs, while there was no difference among images in the proper dose of 1~2 mAs and, especially from 2.5 mAs, average value of pixels radically decreased, affecting contrast. Over 3 mAs, contrast dropped due to saturation phenomenon of lungs. As the result of analysis using Image J program, with the increase of displacement between focus-grid and head phantom, the frequency of low pixel value also increase, causing the outline of surface image to disappear, which in turn affects contrast. For better quality imaging, a radiographer must be aware before the time of test that the image quality can be changed based on the critical patient's posture, movement, respiration, displacement of X-ray tube and distance of imaging.