• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.1
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• pp.85-94
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• 1995

Remote Sensing plays an Important role when we gather and extract many informations about development of the land, circumstances of urbans, land use, surveying resource and marine, geological survey, classification of trees, and condition of trees. For geometric collection to improve the accuracy of positioning with data in the processing of projection treatment by remote sensing. Authors have compared two methods by maps and GPS. Thereafter authors study exact transmation of coordinates in the projection of satellite. Authors have tried to gain improvability of difficulties and problems in the real topography, and Authors consider the coordinates system about global superposition by satellite image.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.275-279
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• 2004

This study was done to detect the topographic and terrain change of the vicinity of the west coast. To make the basic map of the change in topology and terrain, the mosaic images were made using the images from the satellite, which were given the geometric correction based on the GCP (Ground Control Point) and DEM (Digital Elenation Model) data. The accuracy of the images was examined by .empaling them with CCP through 1:25,000's digital map. After that, among the resultant images of the 1970s and 2000s, those of Sihwa, Hwaong and Ansan, the lands reclaimed by drainage were compared to observe the change in the area. From this study, the accuracy of the images of the west coast from satellite could be acquired and the change of the topology and terrain was detected effectively. From the results, it was known that, in case of the land the topological change was not so big due to the development in the reclaimed land or the bare land. In Sihwa, the size of the land was increased 180 $\textrm{km}^2$ and that of the seashore was decreased 110 km. in Hwaong the size was increased 50 $\textrm{km}^2$ and in Ansan the city space was increased 71 $\textrm{km}^2$ due to the formation of the industrial complex.

• The Journal of Korean Physical Therapy
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• v.16 no.1
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• pp.60-69
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• 2004

Many methods have been described for the early intervention of adolescent idiopathic scoliosis. Adolescent idiopathic scoliosis is lateral and rotational spinal curvature in absence of associated congenital or neurologic abnormalities, the most common type of scoliosis observed in child and young adults, and refers to curves that develop after the age of $10{\sim}18$. The curves of adolescent idiopathic scoliosis have the potential to progress rapidly during growth. Curves are currently universally measured by the Cobb's method and Ferguson method. Some curves do not remain small, these may be mildly or severely progressive and the ribs on the convex side of the curve separate, and those on the concave side ribs approximate so rib undergoes deformation with rib humping. The latter may make angles that can affect vestibular system, balance, sensory, especially cardipulmonary function. Intervention for adolescent idiopathic scoliosis is based on the patient's age, the angular value of the curve, the maturity of their skeleton, and the topography. The purpose of intervention for adolescent idiopathic scoliosis consists of knowing how to go to the best approach the correction of the lateral curve and rotational deformity holding the achieved for the remainder of spinal growth, preventing significant cosmetic abnormality, pain and cardiopulmonary complication, control the muscle imbalance and proprioceptive postural disturbances, be less need for radical surgery to avoid early surgery.

• Medical Lasers
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• v.10 no.4
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• pp.229-237
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• 2021

Background and Objectives To assess the effectiveness of overnight orthokeratology (OK) in myopia using a new contact lens design over a one-month wearing period. Materials and Methods Participants were required to have myopia between -3.00 and -7.50D and astigmatism ≤ 2.00 D to participate in the study. The participants underwent OK with the White OK lens^® (Interojo, Pyungtek, Korea), which has a 6-curve lens design. Participants were assessed at weeks 1, 2, and 4 using slit-lamp bio-microscopy, and tested for refraction, uncorrected distance visual acuity, and corneal topography. Success was defined as achieving a Logarithm of the Minimum Angle of Resolution (logMAR) ≤ 0.1. Results A total of 46 eligible subjects with a mean age of 23.11 ± 7.89 years were recruited. Baseline logMAR was 1.18 ± 0.30 and a consistent decrease in logMAR was observed from week 1 to week 4. The success rate was 95.35% at week 4. The mean sphere significantly decreased from a mean pre-fitting value of -4.58 ± 1.28 D to a mean value of -0.65 ± 0.69 D at week 4 (p < 0.0001). Statistically significant corneal flattening was detected during keratometry at week 4. Conclusion Overnight OK with the White OK lens is effective for the correction of moderate and high myopia with astigmatism over a one-month wearing period.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.1
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• pp.12-31
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• 1999

Topex/Poseidon satellite altimetric data are used to estimate characteristics on the oceanic and atmospheric correction factors, and the mean sea level and its variations in the Yellow Sea, the East China Sea and the East Sea from September 1992 through August 1994(70cycles). For the atmospheric correction factors, the variations of dry troposphere, humid troposphere, ionosphere and inverted barometer were very small as a few centimeters, but the variations of electromagnetic bias were higher than other factors. For the oceanic correction factors, the variations of ocean tide(35cm in track 127 and 60cm in track 214) showed high ranges compared to elastic tide(5cm in track 127 and 1cm in track 214) and loading tide(1.8cm in track 127 and 1cm in track 214). It should be understood that the variations of ocean free surface is mainly under the influence of, firstly, ocean tide and, secondly, electromagnetic bias. Mean sea level in the Yellow Sea are higher than in the rest of Seas. Then its range generally comprised between -60cm and 210cm with mean value of about 100cm. Also its variations showed high values in the Yellow Sea and East China Sea, especially 5.689cm in Youngampo. This result is mainly due to the effects of local topography and tidal current.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.1
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• pp.13-18
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• 2009

Accurate solar radiation data are critical to evaluate major physiological responses of plants. For most upland crops and orchard plants growing in complex terrain, however, it is not easy for farmers or agronomists to access solar irradiance data. Here we suggest a simple method using a sun-slope geometry based topographical coefficient to estimate daily solar irradiance on any sloping surfaces from global solar radiation measured at a nearby weather station. An hourly solar irradiance ratio ($W_i$) between sloping and horizontal surface is defined as multiplication of the relative solar intensity($k_i$) and the slope irradiance ratio($r_i$) at an hourly interval. The $k_i$ is the ratio of hourly solar radiation to the 24 hour cumulative radiation on a horizontal surface under clear sky conditions. The $r_i$ is the ratio of clear sky radiation on a given slope to that on a horizontal reference. Daily coefficient for slope correction is simply the sum of $W_i$ on each date. We calculated daily solar irradiance at 8 side slope locations circumventing a cone-shaped parasitic volcano(c.a., 570m diameter for the bottom circle and 90m bottom-to-top height) by multiplying these coefficients to the global solar radiation measured horizontally. Comparison with the measured slope irradiance from April 2007 to March 2008 resulted in the root mean square error(RMSE) of $1.61MJ\;m^{-2}$ for the whole period but the RMSE for April to October(i.e., major cropping season in Korea) was much lower and satisfied the 5% error tolerance for radiation measurement. The RMSE was smallest in October regardless of slope aspect, and the aspect dependent variation of RMSE was greatest in November. Annual variation in RMSE was greatest on north and south facing slopes, followed by southwest, southeast, and northwest slopes in decreasing order. Once the coefficients are prepared, global solar radiation data from nearby stations can be easily converted to the solar irradiance map at landscape scales with the operational reliability in cropping season.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.2
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• pp.64-73
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• 2010

This research collected some multi-image information of Nakdong River Estuary Eulsukdo area in last 30 years, which are used as the basis information in running the qualitative analysis of the topography relief's deformation. First, to obtain the data, this research carried out a field survey and GCP measurement, then classified and collected the image information by analog and digital image. The acquired images which have passed a high-precise scan process and geometric correction is manufactured by Ortho Mosaic image, then divided them into 9 sections time period classification before we run a qualitative analysis. In late of 1980's there are many changes of environmental topography deformation of the Eulsukdo area which caused by large scale building constructions, appeared to be known through this research. And then in late of 1990's, we organized the wild cultivated lands, started the wetland restoration of the artificial ecology, in 2000's we are able to know the existence of topograph relief change which caused by big scale of bridge construction. Hereafter, in this quick process of the environmental and topographical change of this area caused by the 4 major rivers restoration project, the analysis results of this experiment are expected to be something applicable as important basic data.

• Korean Journal of Remote Sensing
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• v.28 no.2
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• pp.191-202
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• 2012

A high resolution satellite imagery such as KOMPSAT-2 includes a material containing rational polynomial coefficient (RPC) for three-dimensional geopositioning. However, image geometries which are calculated from the RPC must have inevitable systematic errors. Thus, it is necessary to correct systematic errors of the RPC using several ground control points (GCPs). In this paper, we propose an efficient method for automatic correction of image geometries using tie points of a stereo pair and the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) without GCPs. This method includes four steps: 1) tie points extraction, 2) determination of the ground coordinates of the tie points, 3) refinement of the ground coordinates using SRTM DEM, and 4) RPC adjustment model parameter estimation. We validates the performance of the proposed method using KOMPSAT-2 stereo pair. The root mean square errors (RMSE) achieved from check points (CPs) were about 3.55 m, 9.70 m and 3.58 m in X, Y;and Z directions. This means that we can automatically correct the systematic error of RPC using SRTM DEM.

• Journal of Yeungnam Medical Science
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• v.17 no.1
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• pp.55-65
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• 2000

Purpose: To compare the efficacy, predictability, stability and safety of excimer laser photorefracive keratectomy(PRK) for myopia and photoastigmatic refractive keratectomy(PARK) for compound myopic astigmatism. Methods: Two-hundred and three eyes(l18 eyes < -7D spherical equivalent, 85 eyes ${\geq}$ -7D spherical equivalent) received excimer laser correction for compound myopic astigmatism and 152 eyes(116 eyes < -7D, 36 eyes ${\geq}$ -7D) for simple myopia. A VISX 20/20B $VisionKey^{TM}$ excimer laser was used to perform either PARK or PRK. Visual acuity with and without correction, refraction, IOP, corneal haze, and topography were evaluated at 1, 3, 6, and 12 months postoperatively. All patients were followed up for more than 12 months. Results: Postoperative refraction were generally stable after 3 months without significant early overcorrection. At 12 months, 110(94.8%) eyes that underwent PRK and 104(88.1%) eyes that underwent PARK achieved UCVA of 20/30 or better in the group who had lower than -7D correction. For eyes treated with -7D or more, these figures were 31(86.1%) eyes after PRK and 57(67.1%) eyes after PARK. The incidences of within 1D of plano refraction at 1 year follow-up were 97.4% after PRK and 93.2% after PARK in the group who had lower than -7D correction. For eyes treated with -7D or more, these figures were 80.6% after PRK and 70.6% after PARK. Conclusions Myopia with or without astigmatism was successfully treated in most of the eyes using PRK or PARK with VISX 20/20B $VisionKey^{TM}$ excimer laser. The predictability and stability of the postoperative refraction during the first 12 months seem to be quite reliable. Further improvement of excimer laser system and software should increase the clinical outcomes and safety of refractive procedures.

• Geophysics and Geophysical Exploration
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• v.17 no.3
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• pp.163-170
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• 2014

Development of a modeling technique for accurately interpreting electromagnetic (EM) data is increasingly required. We introduce finite difference (FD) and finite-element (FE) methods for three-dimensional (3D) frequency-domain EM modeling. In the controlled-source EM methods, formulating the governing equations into a secondary electric field enables us to avoid a singularity problem at the source point. The secondary electric field is discretized using the FD or FE methods for the model region. We represent iterative and direct methods to solve the system of equations resulting from the FD or FE schemes. By applying the static divergence correction in the iterative method, the rate of convergence is dramatically improved, and it is particularly useful to compute a model including surface topography in the FD method. Finally, as an example of an airborne EM survey, we present 3D modeling using the FD method.