• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.3
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• pp.53-61
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• 2012

This paper proposes a real-time distance measurement system of high temperature and high speed target using infrared stereo camera. We construct an infrared stereo camera system that measure the difference between target and background temperatures for automatic target measurement. First, the proposed method detects target region based on target motion and intensity variation of local region using difference between target and background temperatures. Second, stereo matching by left and right target information is used to estimate disparity about real-time distance of target. In the proposed method using infrared stereo camera system, we compare distances in three dimension trajectory measuring instrument and in infrared stereo camera measurement. In this experiment from three video data, the result shows an average 9.68% distance error rate. The proposed method is suitable for distance and position measurement of varied targets using infrared stereo system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.587-598
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• 2021

This study aims to develop a multi-camera based MMS (Mobile Mapping System) technology for building a HD (High Definition) map for autonomous driving and for quick update. To replace expensive lidar sensors and reduce long processing times, we intend to develop a low-cost and efficient MMS by applying multiple cameras and real-time data pre-processing. To this end, multi-camera storage technology development, multi-camera time synchronization technology development, and MMS prototype development were performed. We developed a storage module for real-time JPG compression of high-speed images acquired from multiple cameras, and developed an event signal and GNSS (Global Navigation Satellite System) time server-based synchronization method to record the exposure time multiple images taken in real time. And based on the requirements of each sector, MMS was designed and prototypes were produced. Finally, to verify the performance of the manufactured multi-camera-based MMS, data were acquired from an actual 1,000 km road and quantitative evaluation was performed. As a result of the evaluation, the time synchronization performance was less than 1/1000 second, and the position accuracy of the point cloud obtained through SFM (Structure from Motion) image processing was around 5 cm. Through the evaluation results, it was found that the multi-camera based MMS technology developed in this study showed the performance that satisfies the criteria for building a HD map.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.58-64
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• 2016

In this paper presents Robust k-means clustering-based high-speed bar code decoding method to blur and lighting. for fast operation speed and robust decoding to blur, proposed method uses adaptive local threshold binarization methods that calculate threshold value by dividing blur region and a non-blurred region. Also, in order to prevent decoding fail from the noise, decoder based on k-means clustering algorithm is implemented using area data summed pixel width line of the same number of element. Results of simulation using samples taken at various worst case environment, the average success rate of proposed method is 98.47%. it showed the highest decoding success rate among the three comparison programs.

• Investigative Magnetic Resonance Imaging
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• v.14 no.1
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• pp.31-40
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• 2010

Purpose : To compare the relative values of various fast breath-hold imaging sequences for superparamagnetic iron-oxide (SPIO)-enhanced hepatic MRI for the assessment of solid focal lesions with a 3T MRI unit. Materials and Methods : 102 consecutive patients with one or more solid malignant hepatic lesions were evaluated by spoiled gradient echo (GRE) sequences with three different echo times (2.4 msec [GRE_2.4], 5.8 msec [GRE_5.8], and 10 msec [GRE_10]) for $T2^*$-weighted imaging in addition to T2-weighted turbo spin echo (TSE) sequence following intravenous SPIO injection. Image qualities of the hepatic contour, vascular landmarks and artifacts were rated by two independent readers using a four-point scale. For quantitative analysis, contrast-to-noise ratio (CNR) was measured in 170 solid focal lesions larger than 1 cm (107 hepatocellular carcinomas, nine cholangiocarcinomas and 54 metastases). Results : GRE_5.8 showed the highest mean points for hepatic contour, vascular anatomy and imaging artifact presence among all of the subjected sequences (p<0.001) and was comparable (p=0.414) with GRE_10 with regard to lesion conspicuity. The mean CNRs were significantly higher (p<0.001) in the following order: GRE_10 ($24.4{\pm}14.5$), GRE_5.8 ($14.8{\pm}9.4$), TSE ($9.7{\pm}6.3$), and GRE_2.4 ($7.9{\pm}6.4$). The mean CNRs of CCCs and metastases were higher than those of HCCs for all imaging sequences (p<0.05). Conclusion : Regarding overall performances, GRE using a moderate echo time of 5.8 msec can provide the most reliable data among the various fast breath-hold SPIO-enhanced hepatic MRI sequences at 3T unit despite the lower CNR of GRE_5.8 compared to that of GRE_10.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.8
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• pp.597-609
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• 2020

These days, the coaxial rotor system is used for various purposes like UAVs, Mars exploration helicopters, and the next-generation high-speed rotorcraft. A number of research projects on aerodynamic performance of rotor systems, including the coaxial configuration have been made previously. On the contrary, research on rotor blade deformation has been mainly carried out regarding the single rotor system, where such effort has not been enough on the coaxial system. Nonetheless, in case of the coaxial system, blade deformation analysis is much more important because of the complex air flow around the rotors, and that the distance between the two rotors is a key factor affects aerodynamic performance of the entire system. For these reasons, an experimental study on rotor blade deformation of the coaxial system was conducted using the Stereo Pattern Recognition(SPR) technique, one of the state-of-the-art of photogrammetry method. In this research, a small-scale coaxial rotor test stand designed by Korea Aerospace Research Institute(KARI) was used. With the same test stand, performance of the coaxial configuration had been studied before the experimental study on blade deformation, in order to find the relation between performance and blade deformation of the rotor system. Results of the performance test and the deformation study are presented in this article.

• The Journal of Korean Society for Radiation Therapy
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• v.23 no.1
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• pp.13-19
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• 2011

Purpose: It's essential to minimize the tumor motion and identify the exact location of the lesions to achieve the improvement in radiation therapy efficiency during SBRT. In this study, we made the established compression belt to reduce respiratory motion and evaluated the usefulness of clinical application in SBRT. Materials and Methods: We analyzed the merits and demerits of the established compression belt to reduce the respiratory motion and improved the reproducibility and precision in use. To evaluate the usefulness of improved compression belt for respiratory motion reduction in SBRT, firstly, we reviewed the spiral CT images acquired in inspiration and expiration states of 8 lung cancer cases, respectively, and analyzed the three dimensional tumor motion related to respiration. To evaluate isodose distribution, secondly, we also made the special phantom using EBT2 film (Gafchronic, ISP, USA) and we prepared the robot (Cartesian Robot-2 Axis, FARARCM4H, Samsung Mechatronics, Korea) to reproduce three dimensional tumor motion. And analysis was made for isodose curves and two dimensional isodose profiles with reproducibility of respiratory motion on the basis of CT images. Results: A respiratory motion reduction compression belt (Velcro type) that has convenient use and good reproducibility was developed. The moving differences of three dimensional tumor motion of lung cancer cases analyzed by CT images were mean 3.2 mm, 4.3 mm and 13 mm each in LR, AP and CC directions. The result of characteristic change in dose distribution using the phantom and rectangular coordinates robot showed that the distortion of isodose has great differences, mean length was 4.2 mm; the differences were 8.0% and 16.8% each for cranio-caudal and 8.1% and 10.9% each for left-right directions in underdose below the prescribed dose. Conclusion: In this study, we could develop the convenient and efficient compression belt that can make the organs' motion minimize. With this compression belt, we confirmed that underdose due to respiration can be coped with when CTV-PTV margins of mean 6 mm would be used. And we conclude that the respiratory motion reduction compression belt we developed can be used for clinical effective aids along with the gating system.

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.327-335
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• 2021

The purpose of this study is to find out the use and inconvenience of informatization devices according to the disability of the elderly. A total 10,097 data from the elderly survey were used to analyze the differences in the possession and use of information devices, usage capabilities, and injustice according to disability. Descriptive analysis was conducted to find out general characteristics and disability-related characteristics. chi-square tests were conducted to find out the difference in informatization and communication device usage ability and information device usage inconvenience according to disability. The p-value was set at 0.001. As a result of the study, the elderly with disabilities in Korea had lower smartphones and tablet PCs than the non-disabled elderly. In terms of daily inconvenience, the elderly with disabilities often responded that they had no experience or did not know about the inconvenience of online reservations for trains/high-speed buses/intercity buses, ordering kiosks at restaurants, using ATMs, or reducing bank stores. Taken together, the ability of the elderly with disabilities in Korea to possess and use informatization devices is very low and they feel more inconvenience than the non-disabled elderly. It is necessary to improve the ability to possess and use informatization devices for the elderly with disabilities in the rapidly progressing aging of the disabled and the informatization of our society.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.73-82
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• 2009

Due to the many advantages including low price, low power consumption, and miniaturization, the CMOS camera has been utilized in many applications, including mobile phones, the automotive industry, medical sciences and sensoring, robotic controls, and research in the security field. In particular, the 360 degree omni-directional camera when utilized in multi-camera applications has displayed issues of software nature, interface communication management, delays, and a complicated image display control. Other issues include energy management problems, and miniaturization of a multi-camera in the hardware field. Traditional CMOS camera systems are comprised of an embedded system that consists of a high-performance MCU enabling a camera to send and receive images and a multi-layer system similar to an individual control system that consists of the camera's high performance Micro Controller Unit. We proposed the SL-AVS (Small Size/Low power Around-View System) to be able to control a camera while collecting image data using a high speed synchronization technique on the foundation of a single layer low performance MCU. It is an initial model of the omni-directional camera that takes images from a 360 view drawing from several CMOS camera utilizing a 110 degree view. We then connected a single MCU with four low-power CMOS cameras and implemented controls that include synchronization, controlling, and transmit/receive functions of individual camera compared with the traditional system. The synchronization of the respective cameras were controlled and then memorized by handling each interrupt through the MCU. We were able to improve the efficiency of data transmission that minimizes re-synchronization amongst a target, the CMOS camera, and the MCU. Further, depending on the choice of users, respective or groups of images divided into 4 domains were then provided with a target. We finally analyzed and compared the performance of the developed camera system including the synchronization and time of data transfer and image data loss, etc.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.57-66
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• 2022

The Road Management Administration is cracking down on overloaded vehicles by installing low-speed or high-speed WIMs at toll gates and main lines on expressways. However, in recent years, the act of intelligently evading the overloaded-vehicle control system of the Road Management Administration by illegally manipulating the variable axle of an overloaded truck is increasing. In this manipulation, when entering the overloaded-vehicle checkpoint, all axles of the vehicle are lowered to pass normally, and when driving on the main road, the variable axle of the vehicle is illegally lifted with the axle load exceeding 10 tons alarmingly. Therefore, this study developed a technology to detect the state of the variable axle of a truck driving on the road using roadside camera images. In particular, this technology formed the basis for cracking down on overloaded vehicles by lifting the variable axle after entering the checkpoint and linking the vehicle with the account information of the checkpoint. Fundamentally, in this study, the tires of the vehicle were recognized using the Mask RCNN algorithm, the recognized tires were virtually arranged before and after the checkpoint, and the height difference of the vehicle was measured from the arrangement to determine whether the variable axle was lifted after the vehicle left the checkpoint.

• Korean Security Journal
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• no.24
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• pp.53-66
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• 2010

This study aims to analyze kinematic variables regarding lateral break-fall quantitatively that can protect the body, prevent the injury and minimize the impact. To this end, three Hapkido, judo athletes of H University with experience of over 5 years were selected. Test was conducted through three dimensional image analysis by checking the time and order the subjects reach a mat. In this study, lateral break-fall was repeated five times and among them, the best movement was selected. The picture shot with high-speed camera was analyzed by using KWON3D ver. 3.1 program through three dimensional coordinate calculation based on DLT method and smoothing process of data. Study results were as follows. 1. With respect to time variables shown in lateral break-fall of A, B, C athletes, there is small difference in temporal variables and in the order the body reaches a mat. With respect to average value, hand is ($0.94{\pm}0.20$), elbow ($0.97{\pm}0.17$), hip ($0.97{\pm}0.18$), back ($0.98{\pm}0.18$), and shoulder ($1.04{\pm}0.16$). Time variable the body reaches a mat in lateral break-fall is in hand, elbow, hip, back and shoulder. 2. With respect to moving distance variables shown in lateral break-fall of A, B, C athletes, hand is ($34.33{\pm}34.59$), elbow ($52.00{\pm}26.06$), hip ($70.00{\pm}15.72$), back ($153.67{\pm}17.93$), and should ($130.67{\pm}29.02$). The fact that this study contributed to improving security martial arts technique and protecting the body by understanding the principle of lateral break-fall movement is of significance. In addition, the fact that this study provided systematic basic data for improving security martial arts technique is significant.