• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.277-290
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• 1993

Dental caries is considered to be caused by demineralization by organic acid produced by microorganism. But the formation of subsurface lesion in initial caries make it diffcult to explain by simple demineralization. This study is carried out on the basis of thermodynamic concept proposed by Margolis and Moreno. The purpose of this study is to evaluate the effects of acid concentration and pH of lactate buffer system on the artificial caries lesion progress. 160 teeth without any crack, defect or opaque enamel were used and coated with nail varnish except the window ($2{\times}3$ mm). Under the constant degree of saturation(D.S.). The teeth were divided into 8 groups according to acid concentration(10mM, 25mM, 50mM, 100mM) and pH(4.3, 5.0, 6.0). Each group was immersed in buffer solution for 3, 6, 9, 18 days under controlled temperature($25^{\circ}C$). After cutting through the window and grinding, the specimens, 100-150 um in thickness, were imbibed in water or air and examined using polarilizing microscope. The depth of the surface and subsurface surface lesion were measured. 1. In the constant pH and D. S. value, the subsurface lesion progresses more rapidly as the concentration of lactic acid increases. (0.01, 0.025, 0.05, 0.1) 2. In the constant acid concentration and DS value, the subsurface lesion progresses more slowly as the pH increases. (4.3, 5.0, 5.5, 6.0) 3. The width of surface lesion seems to be constant independant of pH and acid concentration.

• Korean Journal of Digital Imaging in Medicine
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• v.17 no.1
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• pp.33-41
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• 2015

This study attempts to examine the clinical usefulness of High b-value DWI (diffusion weighted imaging) for brain tumors with an edema. Subjects were seven patients selected from 65 patients who received an MRI scan for suspected encephalopathy and confirmed diagnosis at our hospital from February to July 2015 (male: 7, average age : 66 years old). As test equipment, 3.0T MR System (ACHIEVA Release, Philips, Best, The Netherlands) and 8Channel SENSE Head Coill were used. DWI checks on the use of the variable TR 5460ms, TE 132ms, Slice Thickness 4mm, gap 1mm, Slice number 29 is, 3D T1WI is TR 8.4ms, TE 3.9ms, matrix size $240{\times}240$, Slice can set 180 piecesIt was. b value of 0, 1,000, 2,000 s/mm2 with DWI acquisition and 3D T1WI enhancement five minutes after the Slice Thickness 3mm, gap 0mm to reconstruct the upper face axis (MPR TRA CE) was. As for the experiment, in b-value 1,000 and 2,000 images, SNR and the lesion at the lesion site and CNR in the normal site opposite to the lesion are measured. WW(window width) and WL(window level) are made equal in MRICro software, and the volume of the lesion is measured from each of b-value and MPR TRA CE image. Using SPSS ver. 1.8.0.0 Mann Whitney-test was analyzed for SNR and CNR, while Kruskal-Wallis test was analyzed for volume.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.5
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• pp.103-110
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• 2008

A reliable extraction of welded area is the precedent task before the detection of weld defects in industrial radiography. This paper describes an attempt to detect and extract the welded features of steel tubes from the computed radiography(CR) images. The statistical properties are first analyzed on over 160 sample radiographic images which represent either weld or non-weld area to identify the differences between them. The analysis is then proceeded by pattern classification to determine the clustering parameters. These parameters are the width, the functional match, and continuity. The observed weld image is processed line by line to calculate these parameters for each flexible moving window in line image pixel set. The local statistic line-clustering method is used as the classifier to recognize each window data as weld or non-weld cluster. The sequential procedure is to track the edge lines between two distinct regions by iterative calculation of threshold, and it results in extracting the weld feature. Our methodology is concluded to be effective after experiment with CR weld images.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.3
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• pp.241-248
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• 2011

Purpose: The aim of this study was to present the clinical results of maxillary sinus augmentation implants and to evaluate the effects of various factors on the implant survival rate. Methods: In a total of 112 patients, 293 implants after sinus augmentation were performed. The total survival rate and the influence of the following factors on implant survival were evaluated; patient characteristics (sex, age, smoking, general disease), graft material, implant surface, implant installation stage, site of implant placement, length and width of implant, closure method for osseous window, residual alveolar bone height. Results: 1. Age ranged from 16 to 70 yr, with a mean of 45.7 yr. 2. Cumulative survival rate for the 293 implants with the maxillary sinus augmentation procedure was 94.9%. 3. Simultaneous implant installation was performed in 122 patients and delayed implant installation was performed in 117 implants. The average healing period after sinus elevation was 7.3 months for delayed implant installation and this procedure had a significantly higher survival rate. 4. There were no significant differences in sex, age, smoking, general disease, site of implant placement, length and width of implant, residual alveolar bone height and the survival rate. 5. RBM (Resorbable Blasting Media) implant surface and allograft groups had significantly lower survival rates. Conclusion: These data suggest that maxillary sinus augmentation may give more predictable results for autogenous bone grafts and delayed implant placement.

• Journal of environmental and Sanitary engineering
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• v.3 no.2 s.5
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• pp.43-60
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• 1988

This study was carried out to determine traffic noise level and analyze noise reduction effects of various sound protection facilities in the area of Seoul, Inch'on, Songchoo and Seoul- Busan Expressway from March to Octover, 1987. The results were as follows; 1. As compared with the environmental standards and the traffic noise level in heavy noise areas, traffic noise levels observed were shown in higher than environmental standards. The noise levels in Seoul were determined at 12.8-18.2 dB(A) in daytime and 19.0-26.9 dB (A) in nighttime. And incase of inch'on, it were 6.7-9.6 dB(A) in daytime, 7.9-18.9 dB(A) in nighttime, respectively. 2. The environmental noise level observed in the backside of protection facilities, such as apartment, soundproof barrier and houses, which were constructed in paralled to the road was lower about 3-5 dB(A) than perpendicular to theroad. Noise recuction effect of upper stairs in apartment was higher than lower stairs. 3. The predicted noise level obtained from the equation $({\triangle}L\;=\; -10\;log\;(^{I'1}/Ii)\;was\;\pm\;1dB$ (A) and the correlation coefficient (r) was 0.923. 4. The noise reduction effect in backside of apartment was measured at on sites and predicted by total noise loss equation. The predicted noise level was 60.9 dB(A) and the measured level was 60.6 dB(A), respectively. 5. The narrow width landscape less than 10m width was almost no effect for the protection of traffic noise. According to the synthesis of the above results, the noise level of the road was exceeding mostly the environmental standard in the heavy traffic areas. The counterplan should be set as well. The insulation of noise protection facilities were effective by the location with near distance from the road edge. The reduction effect of double window in apartment was represented so much. The prediction model could be applied to estimate the noise levels in the roadside as well as the effectiveness for the noise protection facilities.

• Journal of Chest Surgery
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• v.21 no.3
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• pp.510-517
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• 1988

With the ligation of a patent ductus arteriosus by Gross in 1938, surgeons first entered the field of congenital heart disease, and treatment of the patent ductus is representative of the rapid advance made in thoracic surgery in the last 40 years. We have had clinical experiences about 36 cases of this in the department of Thoracic & Cardiovascular surgery, Pusan Paik Hospital, Inje medical college from March 1891 to June 1987. And the results were summarized as follows. 1. There were 11 males, 25 females. The age range of the patients were from 8 months to 36 years with the mean age of 7.9 years. 2. The chief complaints of the patients on admission were frequent URI[50%], dyspnea on exertion[29.8%], chest pain[11.1% k 1%], growth retardation[2%], cough[2.8%], anorexia[2.8%]. But there were 11 patients[30.6%] having no subjective symptoms. 3. In auscultation, the usual continuous machinery murmur was noticed in 30 patients[83.3%], only systolic murmur in 6[16.7%]. 4. In the preoperative chest P-A views, there were noticed cardiomegaly in 20 cases, enlarged pulmonary conus and / or pulmonary plethora in 22 patients[61.1%]. 5. In the preoperative EGG findings, there were noticed pattern of LVH in 8 patients[22.2`], RVH in 2[5.6%], BVH in 4[11.5%] and normal in 19[52.89o]. 6. The size of PDA[mean] was 9.5 mm[length] and 8.8 mm[width], the range of length was from 4 to 29 mm and the range of width was from 4 to 18 mm. 7. There were noticed 6 cases which were combined with other anomalies[VSD in 2 cases, Coarctation of aorta in 2, Mitral regurgitation in 1, and AP window in 1]. 8. On operation, simple ligation of the ductus was performed in 30 cases[83.3%], division and suture-ligation in 5[13.9%]. 9. Postoperative complications were noticed in 4 cases[pneumonia in one case, wound infection or disruption in 3], but there were no mortality.

• Journal of the Korean Society of Costume
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• v.53 no.8
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• pp.121-135
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• 2003

The purpose of this study is to suggest a theoretical basis to name Sa(紗) and Ra(羅) remains properly by comparing and analyzing the name, usage, value, length and width of Sa(紗) and Ra(羅) recorded on documents made at the end period of Joseon. The features of Sa(紗) and Ra(羅) at the end of the Joseon Period are as follows. 1. The kinds of Sa(紗) are about 80, those of Ra(羅) are about 12, and those of Sa(紗) are significantly more than those of Ra(羅). In regard to the aspect of patterns, there were about 20 types of patterns in the case of Sa(紗), but no specific pattern for Ra(羅). 2. Some newly revealed patterns in the case of Sa (紗) are as follows. Baek -bok-mun(백복문) was a pattern full of ‘bats(박쥐[복])’, and Baek-jeop-mun(백접문) was a pattern full of ‘butterflies(나비[蝶])’ Jeop-mun(접문) was classified into ‘butterfly patterns(나비문[접문])’ and ‘traditional window flame patterns(창살문[접문])‘. 3. When considering the usages of Sa(紗) and Ra(羅), Sa(紗) was used for various detailed purposes according to their kinds and patterns, but Ra(羅) was mostly used for underwear. The most commonly used Sa(紗) was the Gab-sa type(甲紗類). On the contrary, the Go-sa type(庫紗類) was significantly less used than the Gab-sa type(甲紗類). However, it must have been of relatively high quality Sa(紗), shown by the fact that it was used for outer garments. In addition, the Gung-sa type(宮紗類) was the best quality Sa(紗), shown by the fact that it was used for court dress and official uniforms in the royal court. 4. Sa(紗) and Ra(羅) whose features have been examined we Gapsa(甲紗), Sun-in (純仁), Gosa(庫紗), Gwansa(官紗), Jusa(走紗), Eunjosa(은조사), Gwangsa(廣紗), Waesa(倭紗), Dorisa(도리사), Gong-yangsa(공양사), Rasa(羅紗), Danghangra(唐亢羅), Yanghangra(洋亢羅), Yunjura(윤주라), Eunra(銀羅), Jeohangra(저항라), Chura(秋羅). 5. Regarding the values of Sa(紗) and Ra(羅), they were high quality textures and its length and width of 1 Pil(疋), a roll of cloth, were not subdivided in detail such as in the case of plain weaved silks(平絹).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.108-111
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• 2002

CIGS film has been fabricated on soda-lime glass, which is coated with Mo film. by multi-source evaporation process. The films has been prepared with thickness of 1.0 ${\mu}m$, 1.75${\mu}m$, 2.0${\mu}m$, 2.3${\mu}m$, and 3.0${\mu}m$. X-ray diffraction analysis with film thickness shows that CIGS films exhibit a strong (112) preferred orientation. Furthermore. CIGS films exhibited distinctly decreasing the full width of half-maximum and (112) preferred peak with film thickness. Also, The film's microstructure, such as the preferred orientation, the full width at half-maximum(FWHM), and the interplanar spacing were examined by X-ray diffraction. The preparation condition and the characteristics of the unit layers were as followings ; Mo back contact DC sputter, CIGS absorber layer : three-stage coevaporation, CdS buffer layer : chemical bath deposition, ZnO window layer : RF sputtering, $MgF_2$ antireflectance : E-gun evaporation

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.235-243
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• 2002

Theoretical analysis have been performed to design the high power semiconductor laser for an optical sensor at 1.55${\mu}{\textrm}{m}$ wavelength range which is the lowest loss wavelength in optical fiber. The materials of active region and SCH were $Ln_{1-x}Ga_xAs_yP_{1-y}$. In order to use the light source of optical sensors, it has to satisfy wide spectral width and short coherence length. Therefore, in order to suppress lasing oscillation, we proposed laterally tilted PBH type with a window region. Also, tapered stripe structure was applied for high coupling efficiency into a single mode fiber. From these analyses, the devices of laterally tilted angled and bending structure were fabricated and their characteristics were measured. In the results of the measurement, the fabricated devices have sufficient output power and wide FWHM to apply to the light source of optical fiber sensors.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.410.1-410.1
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• 2016

Vanadium dioxide ($VO_2$) is a well-known material that exhibits a metal-semiconductor transition at 340 K, with drastic change of transmittance at NIR region. However, $VO_2$ based thermochromics accompany with low visible transmittance value and unfavorable color (brownish yellow). Herein, we demonstrate the adjustment of visible transmittance of $VO_2$ thin film by nanosphere template assisted patterning process using sol-gel method. 2-Dimenstional honeycomb shape was varied as function of diameter of nanosphere and coating conditions. The morphological geometry of the films was investigated by FE-SEM and AFM. Result shows that inversed shape of nanosphere was formed clearly and pattern width was altered according to the bead size. This structure creates the geometrical blank area from the position of nanosphere which improves the optical transmittance at the visible region. Moreover, such patterned $VO_2$ thin film not only maintains the optical switching efficiency, but also generate the gorgeous scattering effect which presumably support the glazing application.