• Toxicological Research
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• v.19 no.3
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• pp.181-187
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• 2003

Effects of repeated treatment with butylated hydroxyanisole (BHA) on the induction of glutathione S-transferases (GSTs) and teratogenicity of cyclophosphamide were investigated in rats. Pregnant rats were orally treated with BHA (50 mg/kg) for 7 days, from days 6 to 12 of gestation, and intraperitoneally challenged with cyclophosphamide (15 mg/kg) 2 hr after the final treatment. On day 20 of gestation, the maternal and fetal abnormalities were examined. Separately, a part of rats was sacrificed for the assay of hepatic and placental GSTs activities on day 12 of gestation following 7-day treatment with BHA. Cyclophosphamide, administered on day 12 of gestation, induced 43.2% of fetal death and resorption, and 100% of malformations in live fetuses, in contrast to low fetal resorption (8.7%) and malformations (8%) in control group. The malformations include cranial defect and exencephaly (100%), micrognathia and tongue extrusion (100%), limb defects (40%), renal pelvic dilatation (39%), and cleft palate (15%). Interestingly, BHA induced GSTs activities by 62% and 46% over the control in liver and placenta, respectively, and remarkably reduced the fetal resorption (13.9%) and malformations, resulting in 62% of cranial defect and exencephaly, 68% of micrognathia and tongue extrusion, 29% of limb defects, and 14% of renal pelvic dilatation. Taken together, it is suggested that a long-term pretreatment with BHA could substantially prevent fetuses from abortion and malformations following intrauterine exposure to teratogens including cyclophosphamide by inducing phase II antioxidant enzymes such as GSTs.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.761-771
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• 2009

Detecting defects on FPD (Flat Panel Display) color filter before the full panel is made is important to reduce the manufacturing cost. Among many types of defects, the low contrast blemish such as Suzi Mura is difficult to detect using standard CCD cameras. Even skilled inspectors in the inspection line can hardly identify such defects using bare eyes. To overcome this difficulty, point spectrometer has been used to analyze the spectrum to differentiate such defects from normal color filters. However, scanning ever increasing-size color filters by a point spectrometer takes too long time to be used in real production line. We propose a system using a spectral camera which can be viewed as a line scan camera composed of an array of point spectrometers. Three types of lighting system that exhibit different illumination spectrums are devised together with a calibration method of the proposed spectral camera system. To visualize the defect areas, various processing algorithms to identify and to enhance the small differences in spectrum between defective and normal areas are developed. Experiments shows 85% successful visualization. of real samples using the proposed system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1386-1391
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• 2008

The Korean Product Liability Act established the principle that a manufacturer has a duty to take care of a person who is not the customer who bought the product for him. In this instance, there is a duty to the patient for whom the product was purchased by the hospital from the pharmaceutical company. Therefore, the pharmaceutical company has the product liability for adverse reactions to the contrast medium. But the possibility for the patient to successfully sue the pharmaceutical company is quite low, because the patient needs to prove that a "defect" in the unsafe product was the cause of his injuries. And the physician or the radiological technologist can not reduce his liability risks based on the Product Liability Act. On the contrary, The has the product liability because diluting contrast medium belongs to the product category.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.513-516
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• 2007

We introduce a new copolymer alignment film made by bridge-building structure. It is a better film to decrease the image-sticking level in LCD displays. It is noted that the image-sticking was decreased by preventing ion mixing between inter-layers through high hardness. We have investigated the electrical characteristics such as pretilt angle, Residual DC, VHR by changing cure temperature and process delay time conditions of the new alignment film. In this paper, we have investigated the solution for the deep-rooted image defect and incidentally got a contrast ratio improvement by high anchoring force and hardness elevation through the new copolymer alignment film.

• Progress in Superconductivity
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• v.3 no.1
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• pp.36-40
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• 2001

We have studied vortex dynamics in$ Bi_2$$Sr_2$$CaCu_2$O$_{8}$single crystals of unirradiated and irradiated samples by using 100 $\times$ $100\mu\textrm{m}^2$Hall sensor. Doses equivalent magnetic fields are 20 G, 100 G and 1 kG. In the magnetization measurement, a second magnetization peak (SMP) was observed in unirradiated, 20 G dose and 100 G dose samples in contrast to 1 kG dose sample. In the unirradiated sample, the SMP was observed in the range of 18 K ~ 35 K and the amplitude of the SMP decreased with increasing temperature. With increase of the irradiation dose, temperature region and sharpness of the SMP were reduced. In the magnetic relaxation measurement, we observed that the normalized relaxation rate S decreased with increasing the irradiation dose. Our results suggest that the vortex dynamics is not greatly affected by low-density columnar defects.s.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.5
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• pp.211-220
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• 2022

Recently, research on smart factories triggered by the 4th industrial revolution is being actively conducted. Accordingly, the manufacturing industry is conducting various studies to improve productivity and quality based on deep learning technology with robust performance. This paper is a study on the method of detecting tire surface defects in the visual inspection stage of the tire manufacturing process, and introduces a tire surface defect detection method using a depth image acquired through a 3D camera. The tire surface depth image dealt with in this study has the problem of low contrast caused by the shallow depth of the tire surface and the difference in the reference depth value due to the data acquisition environment. And due to the nature of the manufacturing industry, algorithms with performance that can be processed in real time along with detection performance is required. Therefore, in this paper, we studied a method to normalize the depth image through relatively simple methods so that the tire surface defect detection algorithm does not consist of a complex algorithm pipeline. and conducted a comparative experiment between the general normalization method and the normalization method suggested in this paper using YOLO V3, which could satisfy both detection performance and speed. As a result of the experiment, it is confirmed that the normalization method proposed in this paper improved performance by about 7% based on mAP 0.5, and the method proposed in this paper is effective.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.87.1-87.1
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• 2016

The unique properties of 2D materials significantly rely on the atomic structure and defects. Thus study at atomic scale is crucial for in-depth understanding of 2D materials and provides insights into its future applications. Using aberration-corrected transmission electron microscopes, atomic resolution imaging of individual atoms has been achieved even at a low kV. Ongoing optimization of aberration correction improves the spatial resolution better than angstrom and moreover boosts the contrast of light atoms. I present the recent progress of the study on the atomic structure and defects of monolayer and multilayer graphene, hBN and MoS2. Furthermore, the defect formation mechanisms of graphene, hexagonal boron nitride and MoS2 are discussed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.26-26
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• 2003

Lithium storage electrodes for rechargeable batteries require mixed electronic-ionic conduction at the particle scale in order to deliver desired energy density and power density characteristics at the device level. Recently, lithium transition metal phosphates of olivine and Nasicon structure type have become of great interest as storage cathodes for rechargeable lithium batteries due to their high energy density, low raw materials cost, environmental friendliness, and safety. However, the transport properties of this family of compounds, and especially the electronic conductivity, have not generally been adequate for practical applications. Recent work in the model olivine LiFePO$_4$, showed that control of cation stoichiometry and aliovalent doping results in electronic conductivity exceeding 10$^{-2}$ S/cm, in contrast to ~10$^{-9}$ S/cm for high purity undoped LiFePO$_4$. The increase in conductivity combined with particle size refinement upon doping allows current rates of >6 A/g to be utilized while retaining a majority of the ion storage capacity. These properties are of much practical interest for high power applications such as hybrid electric vehicles. The defect mechanism controlling electronic conductivity, and understanding of the microscopic mechanism of lithiation and delithiation obtained from combined electrochemical and microanalytical techniques, will be discussed

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.4
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• pp.336-341
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• 2008

Recently, research on a flat panel display(FPD) has focused on organic light-emitting display(OLED) which has wide angle of view, high contrast ratio and low power consumption. ITO(Indium-Tin-Oxide) films are the most widely used material as a transparent electrode of OLED and also in many other display devices like LCD or PDP. The performance and efficiency of OLED is related to the surface condition of ITO coated glass substrate. The typical surface defect of glass substrate is measured for electric characteristics and physical condition for transmittance and roughness. Since ITO coated glass substrate can be destroyed for inspection about surface roughness, sheet resistance, film thickness and transmittance, precise fabrication condition should be made based on the estimated relationship. In this paper, ITO films were prepared on the commercial glass substrate by the Ion-Plating method changing the partial pressure of gas(Ar, 02) and the chamber temperature between $200^{\circ}C$ and $300^{\circ}C$. The characteristics of films were examined by the 4-point probe, supersonic thickness measurement, transmittance measurement and AFM. We estimated the relationship between processing parameters(Ar gas, O2 gas, Temperature) and properties of ITO films (Sheet Resistance, Film Thickness, Transmittance, Surface Roughness).

• The Korean Journal of Nuclear Medicine
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• v.19 no.2
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• pp.25-41
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• 1985

간흡충증은 한국 및 동남아세아에 널리 분포되어 있는 중요한 풍토병의 하나로서 진단은 전통적으로 분변검사에 의존하여 오고 있다. 최근 들어 담관내 간흡충 및 이의 합병증의 진단을 위해 ERCP 및 contrast cholangiogram등이 시도되었으나 실제에 이용하기에는 많은 제약이 있다 하겠다. 저자는 간흡충증에 있어서 최근 소개된 $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy의 진단적 의의를 규명하고자 1982년부터 1983년까지 고신의대 부속 복음병원에서 검진한 간흡충증 환자 90명을 대상으로 하여 $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy와 formalin-ether 원침법에 의한 분변검사를 시행하였다. $^{99m}Tc-DISIDA$ scintigram소견은 간내 담관 bile flow 및 총수담관 bile flow defect, 그리고 간세포기능의 정도에 따라 자료를 분석하였고 그외 합병증의 진단은 병록 기록, 수술 소견, ERCP 등에 의존하여 결론을 얻었다. $^{99m}Tc-DISIDA$ scintigraphy는 특이한 양상의 bile flow dynamics를 나타내었으며 간내 주담관의 intermittent irregular focal bile flow defect 및 tile flow stasis를 나타내고 말초담관의 bile flow defect는 경미하고 60분 내에 담관 bile flow activity의 완전한 배설을 나타내는 경우를 mild pattern, 간내 담관의 심한 irregular bile flow dynamics 및 간내담관의 심한 irregularity (담관내벽의 심한 불규칙성), 총수담관, 간내 주담관 및 말초 담관까지 심하게 irregular bile flow stasis를 나타내며 bile flow activity의 완전 베설이 $60\sim90$분사이 혹은 90분이상까지 인지된 경우를 moderate-severe pattern으로 분류하였다. 1) 분변검사상 간흡충증은 95검사중 70검사(환자 86명중 67명)에서 양성을 보여 분변 충난검사의 양성율은 73.7%였고 음성율은 26.3%였다. 2) $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy는 90명중 70명에서 특이한 Cs-bile flow양성을 보였으며 양성율은 77.8%였으며 음성율은 22.2%였다. 3) $^{99m}Tc-DISIDA$ hepatobiliary scintigram양성율을 나타낸 환자 70명중 11명은 mild pattern, 59명은 moderate-severe pattern을 나타냈으며 그중 21명은 여러가지 간세포 기능 및 담관에 영향을 미치는 질환과 합병했지만 특이한 Cs-bile flow pattern을 dominent하게 나타내었으며 합병된 여러 질환들도 bile flow pattern상 인지 할 수 있었다. 4) $^{99m}Tc-DISIDA$ hepatobiliary scintigram 음성율을 나타낸 환자 20명중 8명은 만성간염, 5명은 간경변증, 3명은 재발성 농양성담관염(recurrent pyogenic cholangitis)과 간내담도의 stricture 및 담관담석증이 합병되었으며 scintigram상 합병증의 pattern을 나타냈고 4명에서는 low CBD obstruction을 나타내었으며 후에 CBD stone, CBD carcinoma, gall bladder Ca.의 porta hepatis 전이 및 clonorchis worms의 cluster에 의한 obstruction이 operation 및 ERCP로서 진단 되었다. 5) $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy pattern은 현재의 자각증상과 관계된 dominent disease를 나타내었으며, 공간 점유병소도 multiple project images를 시행하므로서 쉽게 발견할 수 있었다. 이와 같이 간흡충증에 있어서 $^{99m}Tc-DISIDA$ hepatobiliary scintigram은 환자의 자각증상과 관계된 질환을 규명하는 데 필요한 정보를 얻었을 수 있었으며 간내담관의 damage정도를 규명하는데 필요한 procedure임이 판명되었다.