• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.191-194
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• 2009

Very big springback in advanced high strength steel(AHSS) sheets invokes undesired shape defects, which can be eliminated by the tool surface correction method or the forming process control method. Since the springback reduction by controlling the forming process is limited, in this study, the die correction method which finds die correction from the relationship between die design variable and springback is introduced to achieve springback reduction and is applied to the automotive side rail to reduce the springback of 75.8% within the assembly limit of 1 mm.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.3
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• pp.102-107
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• 2000

This study describes computer-aided design system for stepped asymmetric forgings. To establish the appropriate process sequence, an integrated approach based on a rule-base system was accomplished. This system has four modules, which are undercut prevention module, shape cognition module, 3D modelling module and corner/fillet correction module. These modules can be used independently or at all. The proposed shape cognition method could be widely used in forging design of asymmetric parts.

• Current Optics and Photonics
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• v.3 no.1
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• pp.72-77
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• 2019

This study was performed to analyze the optical aberrations of the cornea induced by myopic refractive surgery. Corneal total higher-order aberrations, spherical aberration and coma for 4-mm and 6-mm pupils were measured using a wave-front analyzer. The amount of aberrations of the oblate corneal optics by the achieved correction was found to be larger than for the prolate corneal shape with complete eye, in an emmetropia control group. The change in corneal shape acts as an optical factor that degrades the quality of the retinal image; it seems to be one of the important factors related to quality of vision.

• Journal of Sasang Constitutional Medicine
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• v.15 no.2
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• pp.1-8
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• 2003

1. Objects of Research This research is purposed to find role and treatment mind of Sasang constitutional medicine in human genome age, through summarizing recognition of human and etiology. treatment on diseases proposed in Sasang constitutional medicine 2. Methods of Research It was researched as bibliologically with Dong-mu's chief medical writings such as ${\ulcorner}Dongyi$ Soose Bowon(東醫壽世保元)${\lrcorner}$, ${\ulcorner}$Dongyi Soose Bowon Sasang Chongyun(東醫壽世保元四象草本卷${\lrcorner}$. 3. Results and Conclusions 1. The outlook on human of Sasang Constitutional Medicine was completed in the base on Confusianism and it recognized that human is consisted with congenital element based on 'Human nature-shape' and acquired element based on Knowledge-Acting. Dong-mu emphasised acquired element than inborn element. 2. Sasang Constitutional Medicine is thought that we ran overcome inborn limitation of each constitution through moral culture of aposteriori Knowledge-Acting. and that self-correction is methods which is applied to treatment of disease recovering Essential Qi of each constitution with moral culture of personality 3. Sasang Constitutional Medicine is recognizing Essential Qi by main standard that foretell prognosis of disease and emphasize recovery of Essential Qi through self-correction than way of 'Assisting-Good Qi' and 'Removig-Bad Qi' in treatment of disease. 4. Self-correction can be divided into non-herbal self-correction and herbal self-correction. Non-herbal self-correction is to control greed by aposteriori Knowledge-Acting and herbal self-correction is to recover Essential Qi by herb. 5. It is thought that the present constitutional disease is consisted by accumulating life habit nature of a disease of ordinary times, and Sasang Constitutional Medicine that present constitutional disease is treated through administration of life habit nature of a disease of ordinary times in Sasang Constitutional Medicine. 6. Treatment mind to correct oneself into Golden Mean through controlling Knowledge-Acting in Sasang Constitutional Medicine may get into important treatment guide of gene medicine age.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.31-41
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• 2016

Atmospheric correction as a preprocessing work should be performed to conduct accurately landcover/landuse classification using hyperspectral imagery. Atmospheric correction on airborne hyperspectral images was conducted and then the effect of atmospheric correction by comparing spectral reflectance characteristics before and after atmospheric correction for a few landuse classes was analyzed. In addition, land cover classification was first conducted respectively by the maximum likelihood method and the spectral angle mapper method after atmospheric correction and then the results were compared. Applying the spectral angle mapper method, the sea water area were able to be classified with the minimum of noise at the threshold angle of 4 arc degree. It is considered that object-based classification method, which take into account of scale, spectral information, shape, texture and so forth comprehensively, is more advantageous than pixel-based classification methods in conducting landcover classification of the coastal area with hyperspectral images in which even the same object represents various spectral characteristics.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.1
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• pp.1-14
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• 2018

In this study, we develop and propose damping correction factors for the Korean standard design spectra. The newly proposed Korean standard design spectra has been given only for 5% damping ratio. But in practice, engineers need design spectra for damping values other than 5%. To obtain design spectra for various damping values from the standard spectra, damping correction factors are derived. These factors modify the shape of design spectra in accordance with the damping ratio. Response spectra for various damping values are calculated from the earthquake records that had been used to calculate standard design spectra. They consist of 55 records from 18 earthquakes occurred in overseas intraplate regions and Korea. The regressed spectra for the damping values ranging from 0.5% to 50 % are compared with standard spectra at three regions acceleration, velocity and displacement sensitive regions. The regression analysis of these data rendered formula for damping correction factors. Finally, a single formula for damping correction factors is recommended that is valid for both horizontal and vertical design spectra and that is applicable to the entire range of periods. One thing to note that recommended damping correction factors is valid for the design spectrum of the rock grounds because the design spectra was developed based on the earthquake records of the rock ground.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.1
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• pp.27-31
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• 2007

A rolling speed dependent spread model is proposed for predicting the exit cross sectional shape in oval-round (or round-oval) pass rod rolling process when the rolling speed is very high. The effect of rolling speed on the exit cross sectional shape is measured by performing a four-pass continuous high speed (${\sim}80m/s$) rod rolling test and is described in terms of the spread correction parameter. The validity of the model is examined by applying it to rod rolling process at POSCO No.3 Rod Mill. The cross sectional shapes of workpiece predicted by the proposed model coupled with the surface profile prediction $method^{6}$ are in good agreement with those obtained experimentally.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.671-674
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• 2005

Atmospheric correction over the ocean part is more important than that over the land because the signal from the ocean is very small about one tenth of that reflected from land. In this study, the Spectral Shape Matching Method (SSMM) developed by Ahn and Shanmugam (2004) is evaluated using Landsat imagery acquired over the highly turbid Saemangeum Coastal Area. The result of SSMM is compared with COST model developed by Chavez (1991 and 1997). In principle, SSMM is simple and easy to implement on any satellite imagery, relying on both field and image properties. To assess the potential use of these methods, several field campaigns were conducted in the Saemangeum coastal area corresponding with Landsat-7 satellite's overpass on 29 May 2005. In-situ data collected from the coastal waters of Saemangeum using optical instruments (ASD field spectroradiometer) consists of ChI, Ap, SS, aooM, F(d). In order to perform SSMM, we use the in-situ water-leaving radiance spectra from clear oceanic waters to estimate the the path radiance from total signal recorded at the top of the atmosphere (TOA), due to the reason that the shape of clear water-leaving radiance spectra is nearly stable than turbid water-leaving radiance spectra. The retrieved water-leaving radiance after subtraction of path signal from TOA signal in this way is compared with that estimated by COST model. The result shows that SSMM enabled retrieval of water-leaving radiance spectra that are consistent with in-situ data obtained from Saemangeum coastal waters. The COST model yielded significantly high errors in these areas.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.341-343
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• 2006

The current spectral shape matching method (SSMM), developed by Ahn and Shanmugam (2004), relies on the assumption that the path radiance resulting from scattered photons due to air molecules and aerosols and possibly direct-reflected light from the air-sea interface is spatially homogeneous over the sub-scene of interest, enabling the retrieval of water-leaving radiances ($L_w$) from the satellite ocean color image data. This assumption remains valid for the clear atmospheric conditions, but when the distribution of aerosol loadings varies dramatically the above postulation of spatial homogeneity will be violated. In this study, we present the second version of SSMM which will take into account the horizontal variations of aerosol loading in the correction of atmospheric effects in SeaWiFS ocean color image data. The new version includes models for the correction of the effects of aerosols and Raleigh particles and a method fur computation of diffuse transmittance ($t_{os}$) as similar to SeaWiFS. We tested this method over the different optical environments and compared its effectiveness with the results of standard atmospheric correction (SAC) algorithm (Gordon and Wang, 1994) and those from in-situ observations. Findings revealed that the SAC algorithm appeared to distort the spectral shape of water-leaving radiance spectra in suspended sediments (SS) and algal bloom dominated-areas and frequently yielded underestimated or often negative values in the lower green and blue part of the electromagnetic spectrum. Retrieval of water-leaving radiances in coastal waters with very high sediments, for instance = > 8g $m^{-3}$, was not possible with the SAC algorithm. As the current SAC algorithm does not include models for the Asian aerosols, the water-leaving radiances over the aerosol-dominated areas could not be retrieved from the image and large errors often resulted from an inappropriate extrapolation of the estimated aerosol radiance from two IR bands to visible spectrum. In contrast to the above results, the new SSMM enabled accurate retrieval of water-leaving radiances in a various range of turbid waters with SS concentrations from 1 to 100 g $m^{-3}$ that closely matched with those from the in-situ observations. Regardless of the spectral band, the RMS error deviation was minimum of 0.003 and maximum of 0.46, in contrast with those of 0.26 and 0.81, respectively, for SAC algorithm. The new SSMM also remove all aerosol effects excluding areas for which the signal-to-noise ratio is much lower than the water signal.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.287-294
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• 2006

The secondary correction of cleft lip nasal deformity (CLND) presents difficult surgical problems. Characteristically, nostrils are asymmetric. The present study was aimed to examine and compare the effect of Straith's alar web Z-plasty, Millard's alar web Z-plasty, alar web excision, and lateral V-Y advancement of the alar base for augmentation of the nostril with or without lengthening the columella in CLND. The subjects were 28 patients with unilateral cleft lip, who had secondary nostril correction. The nostril correction methods were Straith's alar web Z-plasty, Millard's alar web Z-plasty, alar web excision, and lateral V-Y advancement of the alar base. Facial photographs were taken before and 20 days after the operation. By using Adobe photoshop, the columella length and the nostril width were measured from the facial frontal photograph and Worm's eye view. The degree of improvement was calculated and statistically analyzed. The degree of improvement of the columella length using Straith's alar web Z-plasty was 70.20%. And then Millard's alar web Z-plasty was 55.01%, alar web excision was 39.93%, and lateral V-Y advancement of the alar base was 16.38% in order. The degree of improvement of the nostril size using lateral V-Y advancement of the alar base was 55.26%. And then alar web excision was 52.72%, Millard's alar web Z-plasty was 34.86%, and Straith's alar web Z-plasty was 16.06% in order. Straith's alar web Z-plasty and Millard's alar web Z-plasty resulted in elongation of the columella, equalization of asymmetrical nostril, and enlargement of small nostrils. Alar web excision enlarged nostrils and restored symmetry. Lateral VY advancement of the alar base increased nostril width and enlarged nostrils. These results indicate that the correction of nostrils improve the shape and the symmetry of the nostrils in CLND.