• Journal of radiological science and technology
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• v.40 no.2
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• pp.275-280
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• 2017

In addition to tumors, normal tissues, such as the brain and myocardium can intake $^{18}F$-FDG, and the amount of $^{18}F$-FDG intake by normal tissues can be altered by the surrounding environment. Therefore, a process is necessary during which the contrasts of the tumor and normal tissues can be enhanced. Thus, this study examines the effects of glucose levels on FDG PET images of brain tissues, which features high glucose activity at all times, in small animals. Micro PET scan was performed on fourteen mice after injecting $^{18}F$-FDG. The images were compared in relation to fasting. The findings showed that the mean SUV value w as 0.84 higher in fasted mice than in non-fasted mice. During observation, the images from non-fasted mice showed high accumulation in organs other than the brain with increased surrounding noise. In addition, compared to the non-fasted mice, the fasted mice showed higher early intake and curve increase. The findings of this study suggest that fasting is important in assessing brain functions in brain PET using $^{18}F$-FDG. Additional studies to investigate whether caffeine levels and other preprocessing items have an impact on the acquired images would contribute to reducing radiation exposure in patients.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.735-747
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• 2020

Recent advanced UAV (Unmanned Aerial Vehicle) technology supply new opportunities for estimating crop condition using high resolution imagery. We analyzed the diurnal change of reflectance and NDVI (Normalized Difference Vegetation Index) in UAV imagery for crop monitoring in clear day condition. Multi-spectral images were obtained from a 5-band multi-spectral camera mounted on rotary wing UAV. Reflectance were derived by the direct method using down-welling irradiance measurement. Reflectance using UAV imagery on calibration tarp, concrete and crop experimental sites did not show stable by time and daily reproducible values. But the CV (Coefficient of Variation) of diurnal NDVI on crop experimental sites was less than 5%. As a result of comparing NDVI at the similar time for two day, the daily mean average ratio of error showed a difference of 0.62 to 3.97%. Therefore, it is considered that NDVI using UAV imagery can be used for time series crop monitoring.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.4
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• pp.77-85
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• 1990

The application of remote sensing in small scale mapping has recently been widened to various fields such as information analysis of landuse, environmental conservation and natural resources. SPOT imagery, in particular, offers data which can be processed for 3-dimensional point determination. This is made possible by its high resolution, appropriate swatch width/altitude ratio and stereo imaging capabilities. This study aims to develop a suitable polymonial and an algorithm in the determination of exterior orientation which is essential in the 3-dimensional point determination of SPOT imgery. An algorithm is presented in this study to determine the exterior orientation of a preprocessed level lB film of the satellite image. It was found that a polynominal of 15 parameters is the best fit polynominal for exterior orientation determination, where 1st order line function is used for positon ($X_o$, $Y_o$, $Z_o$) and 2nd order line function is used for orientation (${\kappa}_o$, ${\phi}_o$, ${\omega}_o$).

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.6
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• pp.133-140
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• 2005

This paper presents a rapid face shape acquisition system. The system is composed of two cameras and one projector. The technique works by projecting a pattern on the object and capturing two images with two cameras. We use a 'one shot' system which provides 3D data acquired by single image per camera. The system is good for rapid data acquisition as our purpose. We use the 'absolutely coded pattern' using the hue and saturation of pattern lines. In this 'absolutely coded pattern' all patterns have absolute identification numbers. We solve the correspondence problem between the two images by using epipolar geometry and absolute identification numbers. In comparison to the 'relatively coded pattern' which uses relative identification numbers, the 'absolutely coded pattern' helps obtain rapid 3D data by one to one point matching on an epipolar line. Because we use two cameras, we obtain two images which have similar hue and saturation. This enables us to have the same absolute identification numbers in both images, and we can use the absolutely coded pattern for solving the correspondence problem. The proposed technique is applied to face data and the total time for shape acquisition is estimated.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.637-647
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• 2019

The detection of crop stress is an important issue for the accurate assessment of yield decline. The photochemical reflectance index (PRI) was developed as a remotely sensed indicator of light use efficiency (LUE). The PRI has been tested in crop stress detection and a number of studies demonstrated the feasibility of using it. However, only few studies have focused on the use of PRI from remote sensing imagery. The monitoring of PRI using drone and satellite is made difficult by the low spectral resolution image captures. In order to estimate PRI from multispectral sensor, we propose a band fusion method using adjacent bands. The method is applied to the drone-based hyperspectral and multispectral imagery and estimated PRI explain 79% of the original PRI. And time series analyses showed that two PRI data (drone-based and SRS sensor) had very similar temporal variations. From these results, PRI from multispectral imagery using band fusion can be used as a new method for evaluation of crop stress.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.981-996
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• 2018

In agriculture, remote sensing data using earth observation satellites have many advantages over other methods in terms of time, space, and efficiency. This study analyzed the changes of reflectance and vegetation index according to atmospheric correction of images before using satellite images in agriculture. Top OF Atmosphere (TOA) reflectance and surface reflectance through atmospheric correction were calculated to compare the reflectance of each band and Normalized Vegetation difference Index (NDVI). As a result, the NDVI observed from field measurement sensors and satellites showed a higher agreement and correlation than the TOA reflectance calculated from surface reflectance using atmospheric correction. Comparing NDVI before and after atmospheric correction for multi-temporal images, NDVI increased after atmospheric corrected in all images. garlic and onion cultivation area and forest where the vegetation health was high area NDVI increased more 0.1. Because the NIR images are included in the water vapor band, atmospheric correction is greatly affected. Therefore, atmospheric correction is a very important process for NDVI time-series analysis in applying image to agricultural field.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.315-324
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• 2023

In this paper, we propose a real-time pose estimation method for a monocular camera using a particle filter integrated with UKF (unscented Kalman filter). While conventional camera tracking techniques combine camera images with data from additional devices such as gyroscopes and accelerometers, the proposed method aims to use only two-dimensional visual information from the camera without additional sensors. This leads to a significant simplification in the hardware configuration. The proposed approach is based on a particle filter integrated with UKF. The pose of the camera is estimated using UKF, which is defined individually for each particle. Statistics regarding the camera state are derived from all particles of the particle filter, from which the real-time camera pose information is computed. The proposed method demonstrates robust tracking, even in the case of rapid camera shakes and severe scene occlusions. The experiments show that our method remains robust even when most of the feature points in the image are obscured. In addition, we verify that when the number of particles is 35, the processing time per frame is approximately 25ms, which confirms that there are no issues with real-time processing.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.53-55
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• 2004

In emergency cases, such as the severe trauma involving the fracture of skull, spine, or cervical bone, from auto accident or a fall, and/or pneumothorax which can not be diagnosed exactly by the eye examination, it is necessary the radiological examination during transferring to the hospital for emergency care. The aim of this study was to design and evaluate the prototype of mobile medical image communication system based on CDMA 1X EVDO. The system consists of a laptop computer used as a transmit DICOM client, linked with cellular phone which support to the CDMA 1X EVDO communication service, and a receiving DICOM server installed in the hospital. The DR images were stored with DICOM format in the storage of transmit client. Those images were compressed into JPEG2000 format and transmitted from transmit client to the receiving server. All of those images were progressively transmitted to the receiving server and displayed on the server monitor. To evaluate the image quality, PSNR of compressed image was measured. Also, several field tests had been performed using commercial CDMA2000 1X-EVDO reverse link with the TCP/IP data segments. The test had been taken under several velocity of vehicle in seoul areas.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.1
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• pp.177-182
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• 2010

Sediment transport around artificial habitat which is induced by the change of flow due to installation of the structure plays a role not only as a defect function of subsidence and burial but also bottom-environment control function. Using Side Scan Sonar (SSS), Differential Global Positioning System (DGPS) and Scuba diving equipment, we investigated a facility condition of a dice reef installed on Pohang coast of the East Sea. Investigation result, at total 139 place, 10,526 dice reef was discovered. As the level which affects function of the above 0.5m, the case 4 place of burial (0.5~1.2m, 2.9%), scour appeared with 3 place (0.5m, 2.2%) and broken was appeared with 183 artificial reefs (1.74%). As a result, dice reef installed Pohang coast appeared to mostly stable.

• Tunnel and Underground Space
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• v.28 no.5
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• pp.387-399
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• 2018

Mine reclamation project is closely related to human's past mining activities and the current human's living environment. It is a reason for the national management. In order to efficiently carry out mine reclamation projects, a precise investigation and analysis of the underground space of the abandoned mine is required. Korea MINE RECLAMATION Corp. is developing a practical technology that is effective in investigating and actually measuring underground cavities. MIRECO EYE system is an exploration equipment for 3D digitization and figuration of underground cavities. As combining a laser, sonar and image acquisition technology, it enables access to information about inaccessible underground cavities and effective management of subsidence risk of mined area. and currently it is also utilized for various purposes in related areas such as investigating urban sinkholes. This article is precise numerical and geometric information analysis obtained through MIRECO EYE system.