• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.142-152
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• 2016

GPS is not able to be used for indoor positioning and currently most of techniques emerging to overcome the limit of GPS utilize private wireless networks. However, these methods require high costs for installation and maintenance, and they are inappropriate to be used in the place where precise positioning is needed as in indoor parking lots. This paper proposes a vehicular indoor positioning method based on QR-code recognition. The method gets an absolute coordinate through QR-code scanning, and obtain the location (an relative coordinate) of a black-box camera using the tilt and roll angle correction through affine transformation, scale transformation, and trigonometric function. Using these information of an absolute coordinate and an relative one, the precise position of a car is estimated. As a result, average error of 13.79cm is achieved and it corresponds to just 27.6% error rate in contrast to 50cm error of the recent technique based on wireless networks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2844-2851
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• 2015

How to recover from the multiple 2D images into 3D object has been widely studied in the field of computer vision. In order to improve the accuracy of the recovered 3D shape, it is more important that noise must be minimized and the number of image frames must be guaranteed. However, potential noise is implied when tracking feature points. And the number of image frames which is consisted of an observation matrix usually decrease because of tracking failure, occlusions, or low image resolution, and so on. Therefore, it is obviously essential that the number of image frames must be secured by recovering the missing feature points under noise. Thus, we propose the analytic approach which can control directly the error distance and orientation of missing feature point by the geometrical properties under noise distribution. The superiority of proposed method is demonstrated through experimental results for synthetic and real object.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.117-120
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• 2007

The actual condition of periodic visual acuity testing for 304 undergraduate students were investigated for the purpose of prepared some fundamental data on the development of the eye-health education program and conducting a practical application. Many undergraduate students (59.21%) had not been tested periodic visual acuity testing. The ratio of periodic visual acuity testing for female was higher than male. There was statistical significant difference dependence on the native place, the educational system, and the division of major. The ratio of periodic visual acuity testing for undergraduate students from city was 43.07%, from rural area was 24.32% (p<0.05). According to the educational system, the ratio of periodic visual acuity testing of university students was 65.71%, college students was 27.64% (p<0.001). The ratio of periodic visual acuity testing of undergraduate students who have corrected their visual acuity was 50.25%, while that of students who have not corrected was 23.36% (p<0.001).

• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.103-109
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• 2018

Purpose: This study has been conducted to develop a potato yield monitoring system, consisting of a segmentation algorithm to detect potatoes scattered on a soil surface and a counting system to count the number of potatoes and convert the data from two-dimensional images to masses. Methods: First, a segmentation algorithm was developed using top-hat filtering and processing a series of images, and its performance was evaluated in a stationary condition. Second, a counting system was developed to count the number of potatoes in a moving condition and calculate the mass of each using a mass estimation equation, where the volume of a potato was obtained from its two-dimensional image, and the potato density and a correction factor were obtained experimentally. Experiments were conducted to segment potatoes on a soil surface for different potato sizes. The counting system was tested 10 times for 20 randomly selected potatoes in a simulated field condition. Furthermore, the estimated total mass of the potatoes was compared with their actual mass. Results: For a $640{\times}480$ image size, it took 0.04 s for the segmentation algorithm to process one frame. The root mean squared deviation (RMSD) and average percentage error for the measured mass of potatoes using this counting system were 12.65 g and 7.13%, respectively, when the camera was stationary. The system performance while moving was the best in L1 (0.313 m/s), where the RMSD and percentage error were 6.92 g and 7.79%, respectively. For 20 newly prepared potatoes and 10 replication measurements, the counting system exhibited a percentage error in the mass estimation ranging from 10.17-13.24%. Conclusions: At a travel speed of 0.313 m/s, the average percentage error and standard deviation of the mass measurement using the counting system were 12.03% and 1.04%, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.2
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• pp.235-240
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• 2015

Active Safety system is requested on the market of the medium and heavy duty commercial vehicle over 4.5ton beside the market of passenger car with advancement of the digital equipment proportionally. Unlike the passenger car, the mounting position of camera in case of the medium and heavy duty commercial vehicle is relatively high, it is disadvantaged conditions for lane recognition in contradiction to passenger car. In this work, we show the method of lane recognition through the Sobel edge, based on the spatial domain processing, Hough transform and color conversion correction. Also we suggest the low error method of front vehicles recognition in order to reduce the detection error through Haar-like, Adaboost, SVM and Template matching, etc., which are the object recognition methods by frontal camera vision. It is verified that the reliability over 98% on lane recognition is obtained through the vehicle test.

• Journal of Korean Elementary Science Education
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• v.30 no.2
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• pp.129-140
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• 2011

As one of the casting plans to improve the scientific inquiry ability of the students, the aims of this study are to develop and apply a basic inquiry program for the inquiry subject of Seogwipo fossil formation, and analyze the basis inquiry ability of the students to show in the inquiry activity process actually. The results obtained in 5th grade 48 elementary school students of Seogwipo-city are as follows; Students executed observing activity using an appropriate senses such as senses of vision and touch, and showed the tendency which tries to observe the form overall rather than the partial form of the fossil formation. But the ability to utilize appropriately for predicting and inferring with the facts which could depend on observing activity was low. And we found out that the misconceptions influence on inquiry activity. Therefore, to help understanding deeper for the students' basic inquiry element, it is thought that a study of the various educational guidance ways is necessary to this. The teachers also have to study the various ways to induce the scientific conception through the application of proper teaching-learning for correction of misconceptions because misconceptions have an influence on inquiry activity together. If various inquiry programs considering the regional-specific characteristics are developed to cause students' interest, students would come to participate in inquiry activity aggressively a little more.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.4
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• pp.317-322
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• 2006

For this study we made up a question investigation to analyze a grade of satisfaction and a side effect about the prescription actual condition of contact lens of person with astigmatism among the person who has a error of refraction. The whole patient of refractive error was 46 person, there were 11 person who only wear spectacles by correction of visual acuity among person to a question investigation and 35 person who only wear contact lens. Under investigation 35 person who only wear contact lens, there were 25 person who experience the problem which occurs because of contact lens wearing for a long time. The most patient who made up a question investigation very choose remainder item except for item of very satisfaction. The their reason that could not satisfaction was non corrected astigmatism, wrong prescription, wrong Base curve, out of life span etc.

• Archives of Plastic Surgery
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• v.35 no.4
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• pp.465-470
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• 2008

Purpose: Reduction malarplasty is a popular aesthetic surgery for contouring wide and prominent zygoma. However a few patients complain postoperative results and want to revise the midfacial contour. We analyzed the etiology of unfavorable results and treated unsatisfied midfacial contours after reduction malarplasty. Methods: Total 53 patients were performed secondary operation for correction of unfavorable results after primary reduction malarplasty from elsewhere. Midfacial contour was evaluated with plain films and three-dimensional computed tomography. Unfavorable midfacial contours were corrected by secondary malarplasty. Flaring of zygomatic arch was reduced with infracturing technique and prominent zygomatic body was reduced with shaving. Drooped or displaced zygoma complex has been suspended to higher position and fixed with interosseous wiring. As adjuvant procedure, autologous fat injection has been performed in the region of depressed zygomatic body region. Results: The etiology of unfavorable midfacial contour after reduction malarplasty was classified into 7 categories: undercorrection of zygomatic arch(n=8), undercorrection of zygomatic arch and undercorrection of zygomatic body(n=6), undercorrection of zygomatic arch and overcorrection of zygomatic body(n=28), overcorrection of zygomatic body(n=3), simple asymmetry(n=4), malunion(n=2) or nonunion(n=2). Slim and balanced malar contour was achieved with treatment. And most of the patients were satisfied with the results of the surgery. Conclusion: To prevent the unfavorable results after reduction malarplasty, complete analysis of facial contour, choice of appropriate operation technique, precise osteotomy under direct vision, and security of zygoma position are important.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.164-172
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• 2019

In this paper, we implement a wheeled mobile robot that accurately and autonomously finds the optimal route from the starting point to the destination point based on computer vision in a complex indoor environment. We get a number of waypoints from the starting point to get the best route to the target through deep reinforcement learning. However, in the case of autonomous driving, the majority of cases do not reach their destination accurately due to external factors such as surface curvature and foreign objects. Therefore, we propose an algorithm to deepen the waypoints and destinations included in the planned route and then correct the route through the waypoint recognition while driving to reach the planned destination. We built an autonomous wheeled mobile robot controlled by Arduino and equipped with Raspberry Pi and Pycamera and tested the planned route in the indoor environment using the proposed algorithm through real-time linkage with the server in the OSX environment.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.4
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• pp.308-316
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• 2004

As we know that there are so many restrictions controlling the autonomous robot to turn and move in an indoor space. In this research, Ive adopted the concept ‘Omni-directional wheel’ as a driving equipment, which makes it possible for the robot to move in horizontal and diagonal directions. Most of all, we eliminated the slip error problem, which can occur when the system generates power by means of slip. In order to solve this problem, we developed a ‘slip error correction algorithm’. Following this program, whenever the robot moves in any directions, it defines its course by comparing pre-programmed direction and the current moving way, which can be decided by extracted image of floor line. Additionally, this robot also provides the limited security and service function. It detects the motion of vehicle, transmits pictures to multiple users and can be moved by simple order's. In this paper, we tried to propose a practical model which can be used in an office.