• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.73-81
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• 2000

This review on ocular toxicology concentrates on the effects on ocular health and contact lens wear induced by systemically used drugs, including alcohol. Many systemically administered drugs produce ocular adverse effects. Fortunately, relatively few are capable of causing significant, irreversible visual impairment. The visual symptoms of acute intoxication are as follows : Drop in vision/visual acuity, diplopia, poor dark adaptation, increase in time for glare recovery, early cataract, decreased depth perception, blue-yellow or red-green colour defect and visual hallucinations. Blinking pattern, tear production, and discoloration of contact lenses can be affected by some systemic or local ocular medications. The cornea, conjunctiva, or eyelids may react to some systemic medications and to some preservatives used in contact lens solutions. The hydrogel contact lens act as a drug reservoir that emits the drug over time. I discuss management of contact lens-induced infectious and inflammatory conditions.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.51-61
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• 2001

Cleft lip and/or palate (CLP) is one of the most common congenital craniofacial anomalies and occurs more frequently in Asian people. Dental abnormalities in number, size, shape, and eruption of teeth are frequently associated with CLP. The purposes of this study were to investigate the effects of CLP on number, size, shape and eruption of teeth and to provide basic clinical data for diagnosis and treatment of the CLP patients. With the orthodontic and cleft charts, diagnostic models, orthopantomograms and intraoral x-ray films from 241 CLP patients who visited Dept. of Orthodontics, Seoul National University Dental Hospital, we evaluated the frequency of congenital missing teeth, supernumerary teeth, Impacted teeth, and microdontia. The results were as fellows ; 1. Frequency of congenital missing was relatively high up to $56.8\%$. Congenital missing occurred frequently in the maxillary lateral incisor and the maxillary second premolar. Among the CLP types, frequencies of congenital missing in cleft lip and Palate group and cleft lip and alveolus group were higher than those of cleft lip group and cleft palate group. And bilateral cleft showed higher frequencies than unilateral ones. 2. Supernumerary tooth was shown in $11.2\%$ of CLP patients. It occurred frequently in the area between the maxillary lateral Incisors and the maxillary canine. Among the CLP types, cleft lip group showed relatively most highest frequency. 3. Impaction was shown in $18.3\%$ of CLP patients. It occurred most frequently In the maxillary lateral incisor and the maxillary canine than other teeth. Among the CLP types, cleft lip group and cleft lip and palate group showed most highest frequencies. 4. Microdontia was shown in $15.8\%$ of CLP patients. It occurred the most frequently In the maxillary lateral incisors and maxillary canines. Among the CLP types, cleft lip and alveolus group and cleft lip and palate group showed relatively higher frequencies. There was no microdontia in cleft palate group.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.581-588
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• 2019

MRI is superior when contrasted to help the organization generate artifacts resolution, but also affect the diagnosis and create a image that can not be read. Metal is inserted into the tooth, it is necessary to often be inhibited in imaging by causing the geometric distortion due to the majority and if the difference between the magnetic susceptibility of a ferromagnetic material or paramagnetic reducing them. The purpose of this study is to conduct a metal artefact in accordance with the analysis using a diamagnetic material. The magnetic material include a wire for the orthodontic bracket and a stainless steel was used as a diamagnetic material was used copper, zinc, bismuth. Testing equipment is sequenced using 1.5T, 3T was used was measured using a SE, TSE, GE, EPI. A self-produced phantom material was used for agarose gel (10%) to a uniform signal artifacts causing materials are stainless steel were tested by placing in the center of the phantom and cover inspection of the positive cube diamagnetic material of 10mm each length.After a measurement artefact artifact zone settings area was calculated using the Wand tool After setting the Low Threshold value of 10 in the image obtained by subtracting images, including magnetic material from a pure tool phantom images using Image J. Metal artifacts occur in stainless steel metal artifact reduction was greatest in the image with the bismuth diamagnetic materials of copper and zinc is slightly reduced, but the difference in degree will not greater. The reason for this is thought to be due to hayeotgi offset most of the susceptibility in bismuth diamagnetic susceptibility of most small ferromagnetic. Most came with less artifacts in image of bismuth in both 1.5T and 3T. Sequence-specific artifact reduction was most reduced artifacts from the TSE 1.5T 3T was reduced in the most artifacts from SE. Signal-to-noise ratio was the lowest SNR is low, appears in the implant, the 1.5T was the Implant + Bi Cu and Zn showed similar results to each other. Therefore, the results of artifacts variation of diamagnetic material, magnetic susceptibility (${\chi}$) is the most this shows the reduced aspect lower than the implant artificial metal artifacts criteria in the video using low bismuth susceptibility to low material the more metal artifacts It was found that the decrease. Therefore, based on the study on the increase, the metal artifacts reduction for the whole, as well as dental prosthesis future orthodontic materials in a way that can even reduce the artifact does not appear which has been pointed out as a disadvantage of the solutions of conventional metal artifact It is considered to be material.

• Progress in Medical Physics
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• v.17 no.3
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• pp.173-178
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• 2006

The purpose of this study was to evaluate the radiation dose for clinical PET/CT protocols in clinical environments using Alderson phantom and TLDs. Radiation doses were evaluated for both Philips GEMINI 16 slice PET/CT system and GE DSTe 16 slice PET/CT system. Specific organ doses with $^{137}Cs$ transmission scan, high quality CT scan and topogram in philips GEMINI PET/CT system were measured. Specific organ doses with CT scan for attenuation map, CT scan for diagnosis and topogram in GE DSTe PET/CT system were also measured. The organs were selected based on ICRP60 recommendation. The TLDs used for measurements were selected for within an accuracy of ${\pm}5%$ and calibrated in 10 MV X-ray radiation field. The effective doses for $^{137}Cs$ transmission scan, high qualify scan, and topogram in Philips GEMINI PET/CT system were $0.14{\pm}0.950,\;29.49{\pm}1.508\;and\;0.72{\pm}0.032mSv$ respectively. The effective doses for CT scan to make attenuation map, CT scan to diagnose and topogram in GE DSTe PET/CT system were $20.06{\pm}1.003,\;24.83{\pm}0.805\;and\;0.27{\pm}0.008mSv$ respectively. We evaluated the total effective dose by adding effective dose for PET Image. The total PET/CT doses for Philips GEMINI PET/CT (Topogram+$^{137}Cs$ transmission scan+PET, Topogram+high qualify CT+PET) and GE DSTe PET/CT (Topogram +CT for attenuation map+ PET, Topogram+diagnostic CT+ PET) are $7.65{\pm}0.951,\;37.00{\pm}1.508,\;27.12{\pm}1.003\;and\;31.89{\pm}0.805mSv$ respectively. Further study may be needed to be peformed to find optimal PET/CT acquisition protocols for reducing the patient exposure with good image qualify.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.107-112
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• 2008

urpose: This thesis is a study the Night myopia was surveyed by Subjective refraction and Objective refraction (Dark retinoscopy), and analyzed the relationship between them. It also looked at the relation between Night myopia and pupil size. Methods: 82 adult subjects (ages of 19 to 44, 44 males and 38 females) were examined by Subjective refraction and Objective refraction in the light place. Then Night myopia and pupil size were examined by Subjective refraction and Objective refraction in the dark again. The Statistics were analyzed by SPSS (Statistical Package for Social Science). Results: As the subjects became younger, the observed Night myopia was getting higher in both Subjective refraction, $x^2$=219.48 (p<0.01) and Objective refraction, $x^2$=241.98 (p<0.01). The relationship was statistically significant by showing large pupil size, $x^2$=151.74 (p<0.01). In Objective refraction, as pupil size became larger in the dark place, so did Night myopia, $x^2$=84.27 (p<0.01), reaching a statistically significant correlation, however, the correlation was low in Subjective refraction. In Subjective refraction, observed Night myopia was 73%, 64 examples of 88 examples, a standard of 0.96${\pm}$0.4584D in ${\pm}$0.25D, in male examples, and it was 64%, 49 examples of 76 examples, a standard of 1.01${\pm}$0.4509D in ${\pm}$0.25D, in female examples. In Objective refraction, it was 48%, 42 examples of 88 examples, in standard of 0.85${\pm}$0.4651D in ${\pm}$0.25D, in male examples. And it was 71%, 54 examples of 76 examples, in standard of 0.96${\pm}$0.4133D in ${\pm}$0.25D, in female examples. Conclusions: Night myopia which is measured by both methods, observed as $x^2$=265.35 (p<0.01) and showed a large relationship. The correlation between the two refractions suggests that observed night myopia diopter by Subjective refraction could be used as correction of night myopia.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.650-663
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• 2007

The purpose of this study was to identify the sanitation management items of school foodservice suppliers that require improvement, by assessing their sanitation practices with food commodities. Our field assessment was performed using a total of 20 vendors supplying agricultural products, meat products, seafoods and processed products; all were located in the Seoul and Gyeonggi areas. The assessment tool for sanitation management was composed of 93 checklist items and was used to evaluate seven different categories; the facility and environment, management of the facility and equipment, food materials management, process control, water management, personal hygiene management, and laboratory instrument management. A score of two was given for "satisfactory", one for "fair", and zero for "unsatisfactory". The overall average supplier score was 1.7/2.0 (85.8%). The score of the seafood vendors was highest at 1.9 (95.4%), while the lowest score of 1.3 (65.7%) occurred with the processed product suppliers. Among the sanitation management categories, water management was scored at 2.0, while inspection management was lowest at 1.4. The subcategories indicating needed improvements for the processed product suppliers were raw materials, storage, transport and recall. For the agricultural product suppliers it was preparation management. furthermore, one item within the laboratory instrument management category was unsatisfactory for both the agricultural and processed product suppliers. In conclusion, these results can be used to develop sanitation management procedures for suppliers, as well as by administration agencies to evaluate and guide those suppliers.

• The Journal of Korean Association of Computer Education
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• v.23 no.4
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• pp.23-33
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• 2020

Online judge provides compilation, execution, and immediate feedback on the source submitted by the learner, and ensures the accuracy and reliability of the evaluation, but it's difficult to select the language according to the level of the learner because most of them provide only textual language. In this study, a block language for online judge was developed and applied to high school classes, and the difference in self-efficacy between the block language and the textual language group was confirmed. It was found that Block language group have more ability expectation to overcome disgust experience than textual language group and Textual language group have significant decrease in ability expectation to start activity and to continue activity. It implies that Block language has an effect on self-efficacy for afterward programming activities, and methods of teaching, learning and evaluation should be devised in the case of textual language so that student's self-efficacy does not deteriorate at the initial and ongoing stage of activity. The results of this study are meaningful in that it provide various implications of methods for enhancing self-efficacy in high school class of programming.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.3
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• pp.209-215
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• 2013

Cleft lip and palate, the most common craniofacial anomalies, are severe congenital defects that have an incidence of 0.28 to 3.74 per 1000 live births. Although there has been great improvement in the field of cleft surgery, surgical approach cannot be the single solution to resolve the various problems encountered in patients with cleft lip and palate. The concept of presurgical infant orthopedics (PSIO) for gradual closure of the cleft gap and simplified surgical performance was first introduced by McNeil in 1950. Recently, there are many attempts not only to approximate the alveolar segments but also to reshape the nasal cartilage. Three infants with unilateral cleft lip and palate were referred from the department of Plastic Surgery for presurgical nasoalveolar molding (PNAM). Maxillary appliances using resin with orthodontic wire were fabricated. Then these appliance was applied until patients underwent lip surgery. In all cases, the patients could wear the appliance all day since they were able to eat even with the appliance on, This resulted in significant improvements in the nasal symmetry were found. Our appliance, namely K-NAM, extends the wearing time within the limited period and as a result it is expected to maximize the treatment effects. Used properly, this appliance would play a major role in enhancing nasal symmetry with satisfactory results.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.44-44
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• 1999

저진공(1 kPa~ 100 kPa)은 대기압 측정, 비행고도, 기체의 온도 측정, 질량의 부력 보정, 레이저의 굴절률 측정등에 사용되는 영역으로 과학적 중요성을 갖고 있다. 또한 대기압 이상의 압력 측정과 고진공 측정의 경계적 역할도 수행하고 있어 압력 표준기의 국제 비교에 필수적으로 권장되는 역역이다. 이 영역에 주로 사용되는 압력 표준기는 수은 압력계(Mercury manometer)와 분동식 압력계(Deadweight piston gauge or Pressure)가 있다. 이들은 이동이 불편하거나 불가능하므로 표준기의 국제 비교에 사용되는 전달 표준기로는 보다 이동이 간편한 탄성 압력계인 CDG(Capacitance diaphragm Gauge)가 있다. 이 게이지는 반도체 산업의 공정 제어용으로도 많이 사용되고 있다. 그러나 게이지와 함께 사용되는 컨트롤러의 부피가 크고 무거우며 영점 이동이 커서 측정때 마다 재조정하여야 하는 단점이 있다. 본 논문에서는 이 같은 단점을 극복하기 위해 수정빔 진동형 진공 센서를 잔달 표준기로 사용하는 것에 대한 연구를 수행하였다. 수정빔 진동형 압력 센서는 수정빔으 공진주파수가 스트레인에 비례하는 것을 이용하여 제작된 센서로 주로 대기압 이상의 고압 측정에 많이 사용되고 있다. 먼저 수정빔의 압력과 주파수간의 관계를 측정하고 또한 내장된 수정 온도센서의 공진 주파수를 측정하여 온도 보상을 위한 자료로 사용하였다. 규격에 나와 있는 수정빔의 기하학적 형상으로부터 거동에 관한 이론 모델식을 구하고 압력교정 자료로부터 얻어진 데이터를 이 식과 비교 분석하여 적합한 특성식과 인자를 구하였으며 게이지의 불확도를 추정하였다.모델은 길이가 유한한 0-차원 실린더 모델로 가정하였고, 이에 대한 기하학적 성질 및 열역학적 성질은 유효계수를 고려하여 산출하였다. 진공용기 이중 벽 내부로 흐르는 질소가스의 유량과 온도의 계산은 진공용기 내벽과 외벽을 각각 독립적인 열전달 요소로 가정하여 구성한 모델을 이용하였다. 전체 해석에서 각 열전달 요소의 비열 값은 온도에 따라 변화하는 비열의 특성을 반영하였으며. 진공용기와 플라즈마 대향 부품의 방사율(emissivity)은 앞서 가정했던 각 온도 상승 곡선에 대해서 각각 0.1, 0.2, 1.3의 경우를 가정하여 계산하였다. 직선적으로 증가하는 온도 상승 곡선중 2$0^{\circ}C$/hr의 온도상승율을 갖는 경우가 다른 베이킹 시나리오 모델에 비해 효과적이라 생각되며 초대 필요 공급열량은 200kW 정도로 산출되었다. 실질적인 수치를 얻기 위해 보다 고차원 모델로의 해석이 필요하리라 생각된다. 끝으로 장기적인 관점에서 KSTAR 장치의 베이킹 계획도 살펴본다.습파라미터와 더불어, 본 연구에서 새롭게 제시된 주기분할층의 파라미터들이 모형의 학습성과를 높이기 위해 함께 고려된다. 한편, 이러한 학습과정에서 추가적으로 고려해야 할 파라미터 갯수가 증가함에 따라서, 본 모델의 학습성과가 local minimum에 빠지는 문제점이 발생될 수 있다. 즉, 웨이블릿분석과 인공신경망모형을 모두 전역적으로 최적화시켜야 하는 문제가 발생한다. 본 연구에서는 이 문제를 해결하기 위해서, 최근 local minimum의 가능성을 최소화하여 전역적인 학습성과를 높여 주는 인공지능기법으로서 유전자알고리즘기법을 본 연구이 통합모델에 반영하였다. 이에 대한 실

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.357-365
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• 1998

목적: 치과용 수복재료의 방사선 불투과성은 매우 다양하다. 따라서 다양한 수복재료의 방사선 불투과성을 인지하여 치질과 비교하면 이차우식의 진단에 도움이 될 수 있다. 도재의 방사선 불투과성에 따라 적절한 luting cement의 선택이 가농해진다. 수복재료의 방사선 불투과성은 알루미늄 step wedge 의 후경과 방사선 불투과성과의 상관관계 의해 측정된다. 본 연구의 목적은 CAD/CAM용 도재와 이틀의 접착에 쓰이는 접착재료의 방사선 불투과성을 조사해 적절한 재료의 선택과 이차우식 진단의 효율결정에 도움이 되게 하는데 있다. 방법: 본 실험에서는 CAD/CAM용 도재인 Vita MarkII, Dicor MGC와 이의 접착에 사용되는 Z-100, 그리고 luting cement인 Duo cement, Scotchbond resin cement를 사용해 방사선 불투과성을 측정하였다. 시편 제작을 위해 도재를 저속절단기로 두께 2mm, 3mm로 절단하였으며 Z-100과 cement시편은 두께 2mm와 3mm, 직경 7.0mm의 금속 주형을 제작한 후 재료를 양쪽 면에 유리판을 대고 조임쇠로 압접하였으며 광조사기를 사용하여 각 재료마다 두 가지 두께로 10개씩 100개의 시편을 제작하였다. 치질의 시편을 얻기 위해 교정 목적으로 최근에 발거된 정상적인 상악 소구치를 저속 절단기를 사용하여 협설측 교두정을 기준 삼아 2mm, 3mm 두께로 절단하였으며 방사선 불투과성의 기준을 위해 12개의 step으로 구성된 12mm두께의 aluminum step wedge를 사용하였다. Kodak E-Speed occlusal film에 aluminum step wedge와 시편들을 위치시킨 후 70kVp, 7mA, 2.16mm aluminum filtration으로 고정된 dental X-ray unit을 사용하여 target과 film 사이의 거리는 25cm, 노출시간은 0.2초로 하여 방사선 촬영을 한 다음, 현상된 방사선 사진상에 나타난 방사선 불투과성을 X-rite 301 densitometer를 이용하여 측정한 값들의 평균을 냈다. 얻어진 결과는 one-way ANOVA Duncan test(P<0.01)로 검증하였다. 결론: 1. Dicor MGC의 방사선 불투과성은 법랑질보다 약간 높게 나타났다.(P<0.01) 2. Vita Mark Il는 상아질보다 낮은 방사선 불투과성을 보였다.(P<0.01) 3. Z-100과 Luting cement들의 방사선 불투과성은 법랑질보다 높았다. Duo cement가 방사선 불투과성이 가장 높았고 그 다음이 Z-100, 그리고 Scotchbond resin cement 순이었다. 4. Z-100과 2종류의 방사선 불투과성 luting cement들은 Vita Mark II 와 같이 사용하면 2차우식 진단에 도움이 된다.