• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.47-53
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• 2012

Recently many developed countries have used satellite images for classifying cropland areas to reduce time and efforts put into field survey. Korea also has used satellite images for the same purpose since KOMPSAT-2 was successfully launched and operated in 2006, but still far way to go in order to achieve the required accuracy from the products. This study evaluated the accuracy of the calculated croplands by using the objected classification method with various satellite images including ASTER, Spot-5, Rapid eye, Quickbird-2, Geo eye-1. Also, their usability and effectiveness for the cropland survey were verified by comparing with field survey data. As results. Geo eye-1 and Rapid eye showed higher accuracy to calculate the paddy field areas while Geo eye-1 and Quickbird-2 showed higher accuracy to calculate the upland field areas.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.203-212
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• 2012

This study aims to test presence of spatial autocorrelation of burn severity in Uljin and Youngduk areas burned in 2011. SPOT satellite images were used to compute the NDVI representing burn severity, and NDVI values were sampled for 5,000 randomly dispersed points for each site. Spatial autocorrelations of sampled NDVI values were analyzed with Moran's I and Variogram models. Moran's I values of burn severity in Uljin and Youngduk areas were 0.7745 and 0.7968, respectively, indicating presence of strong spatial autocorrelations. On the basis of Variogram and changes of Moran's I values by lag class, ideal sampling distance were proposed, which were 566-2,151 m for Uljin and 272-402 m for Youngduk. It was recommended to apply these ranges of sampling distance in flexible corresponding to Anisotropic characteristics of burned areas.

• Journal of the Korea Society of Computer and Information
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• v.26 no.5
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• pp.9-16
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• 2021

In this paper, we propose a building exploration drone that can be used for a digital twin-based building control system. The existing building control system using a fixed position sensor box has a problem that a management blind spot occurs. And because people patrol themselves, it takes a lot of human resources. In this paper, a drone equipped with a temperature and humidity sensor and a gas leak detection sensor is used to search the internal path of the building centering on the control blind spot. It also aims to solve the problem of the building control system by transmitting information in real time along with the video. In addition, it has a stable hovering function using an optical floor sensor and can be applied to an existing digital twin-based building control system. The results of this study are believed to be of great help in improving the quality of digital twin control systems using drones.

• Journal of Korea Multimedia Society
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• v.15 no.5
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• pp.677-691
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• 2012

Location Based Services using GPS receiver with network enabled smart phone provides various services and many business models. Currently, many context awareness models on smart phone applications are under developing. But most of the services are based on current user position and Point of Interest(POI)s, which are very static. In this paper, we proposed and implemented multimedia tourist guide system using smart phone, which are very dynamic and provides tour guide's voice and audio service on the spot. Also we provides tour experience sharing method which can easily share the videos and pictures for each users.

• Journal of the Korean Society of Visualization
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• v.7 no.1
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• pp.9-13
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• 2009

Fluorescence recovery after photobleaching (FRAP) has been widely used for the measurement of molecular diffusion in living cells and tissues. We developed an image-based FRAP (iFRAP) technique using a modified real-time microscope and a 488 nm Ar-ion laser. A fractional intensity curve was obtained from the time-lapse images of fluorescence recovery in the bleached spot to determine the diffusion coefficient of fluorescently labeled macromolecules in porous medium. We validated iFRAP through experiments with agar gels (0.5% and 1.5% w/v) containing FITC-Dextrans (10, 70 and 500 kDa MW). Further validation was performed by a Monte Carlo approach, where we simulated the three-dimensional random walk of macromolecules in agar gel model. Diffusion coefficients were deduced from the mean square displacement curves and showed good agreements with those measured by iFRAP.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.131-136
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• 2016

In this paper, we propose an Raspberry Pi2-based smart home security monitoring system. Proposed home security monitoring system was configured using a relatively tractable main processor raspberry pi2, ultrasonic sensors, and PIR sensors. In addition, The picamera is compatible with raspberry pi2 was connected to the servo motor. And by driving the attacker's location the video was recording. The Web server stores data of the recorded image and the sensor, and provides a web page to enable the monitoring at all remote locations. When examining efficiency of proposed home security monitoring system it was found that proposed system is easier to be made than existing home security system and is able to minimize the blind spot of the camera by using servo motor and is efficient and convenient and stable as it enables a user to handle an error in person and it uses reliable data.

• Korean Journal of Digital Imaging in Medicine
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• v.10 no.1
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• pp.35-40
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• 2008

I.objective The composition method with acquiring 2${\sim}$5 image not only lack perfection in compensating the geometrical distortion but could also cause inaccurate connection problem of compensating the geometrical distortion but could also cause inaccurate connection problem of continuing bone structure due to the enlargement ratio difference of ruller and bone, density difference in image composition process. This paper studies those mentioned problems through the experiments. II. Object and method Experiment 1 After attaching 3 step wedge(Pb) on detector and 2 ruller on upper, lower part of the step wedge, we have exposed them to create density difference between 1st image and 2nd image, then examined if there were any errors. Experiment 2 1st 100cm ruller was attached on the center of detector, and by escalating the distance between 2nd 100cm ruller and detector 5cm, 10cm, 15cm respectively, we investigated if there any errors caused by enlargement ratio. Experiment 3 The ruller was placed on detector, a joint photographing was performed through spot photographing after fully operating the electric field photographing to include hip joint ${\sim}$ ankle joint part and we have compared the values from two methods. III. Result : A horizontal axis error was caused when photopraphing is not poerated in equal density since the image shifted horizontally in accordance with the difference of Pb step wedge 1 due to the density difference, as the result of Epperiment 1.

• Ocean and Polar Research
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• v.35 no.1
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• pp.1-14
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• 2013

Shoreline data of the barrier islands in Nakdong River Estuary for the last three decades were assembled using six sets of aerial photographs and seven sets of satellite images. Canny Algorithm was applied to untreated data in order to obtain a wet-dry boundary as a proxy shoreline. Digital Shoreline Analysis System (DSAS 4.0) was used to estimate the rate of shoreline changes in terms of five statistical variables; SCE (Shoreline Change Envelope), NSM (Net Shoreline Movement), EPR(End Point Rate), LRR (Linear Regression Rate), and LMS (Least Median of Squares). The shoreline in Jinwoodo varied differently from one place to another during the last three decades; the west tail has advanced (i.e., seaward or southward), the west part has regressed, the south part has advanced, and the east part has regressed. After the 2000s, the rate of shoreline changes (-2.5~6.7 m/yr) increased and the east advanced. The shoreline in Shinjado shows a counterclockwise movement; the west part has advanced, but the east part has retreated. Since Shinjado was built in its present form, the west part became stable, but the east part has regressed faster. The rate of shoreline changes (-16.0~12.0 m/yr) in Shinjado is greater than that of Jinwoodo. The shoreline in Doyodeung has advanced at a rate of 31.5 m/yr. Since Doyodeung was built in its present form, the south part has regressed at the rate of -18.2 m/yr, but the east and west parts have advanced at the rate of 13.5~14.3 m/yr. Based on Digital Shoreline Analysis, shoreline changes in the barrier islands in the Nakdong River Estuary have varied both temporally and spatially, although the exact reason for the shoreline changes requires more investigation.

• Progress in Medical Physics
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• v.19 no.2
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• pp.102-112
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• 2008

We developed a high-resolution micro-CT system based on rotational gantry and flat-panel detector for live mouse imaging. This system is composed primarily of an x-ray source with micro-focal spot size, a CMOS (complementary metal oxide semiconductor) flat panel detector coupled with Csl (TI) (thallium-doped cesium iodide) scintillator, a linearly moving couch, a rotational gantry coupled with positioning encoder, and a parallel processing system for image data. This system was designed to be of the gantry-rotation type which has several advantages in obtaining CT images of live mice, namely, the relative ease of minimizing the motion artifact of the mice and the capability of administering respiratory anesthesia during scanning. We evaluated the spatial resolution, image contrast, and uniformity of the CT system using CT phantoms. As the results, the spatial resolution of the system was approximately the 11.3 cycles/mm at 10% of the MTF curve, and the radiation dose to the mice was 81.5 mGy. The minimal resolving contrast was found to be less than 46 CT numbers on low-contrast phantom imaging test. We found that the image non-uniformity was approximately 70 CT numbers at a voxel size of ${\sim}55{\times}55{\times}X100\;{\mu}^3$. We present the image test results of the skull and lung, and body of the live mice.

• Progress in Medical Physics
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• v.26 no.4
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• pp.215-222
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• 2015

In this work, we performed a proof-of-concept experiment for phase-contrast x-ray imaging (PCXI) based on a single antiscatter grid and a polychromatic x-ray source. We established a table-top setup which consists of a focused-linear grid having a strip density of 200 lines/inch, a microfocus x-ray tube having a focal-spot size of about $5{\mu}m$, and a CMOS-type flat-panel detector having a pixel size of $48{\mu}m$. By using our prototype PCXI system and the Fourier demodulation technique, we successfully obtained attenuation, scattering, and differential phase-contrast images of improved visibility from the raw images of several selected samples at x-ray tube conditions of $90kV_p$ and 0.1 mAs. Further, fusion image (e.g., the attenuation+the scattering) may have an advantage in displaying details of the sample's structures that are not clearly visible in the conventional attenuation image. Our experimental results indicate that single-grid-based approach seems a useful method for PCXI with great simplicity and minimal requirements on the setup alignment.