• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.183-183
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• 2021

Deep learning methods and their application have become an essential part of prediction and modeling in water-related research areas, including hydrological processes, climate change, etc. It is known that application of deep learning leads to high availability of data sources in hydrology, which shows its usefulness in analysis of precipitation, runoff, groundwater level, evapotranspiration, and so on. However, there is still a limitation on microclimate analysis and prediction with deep learning methods because of deficiency of gauge-based data and shortcomings of existing technologies. In this study, a real-time rainfall prediction model was developed from a sky image data set with convolutional neural networks (CNNs). These daily image data were collected at Chung-Ang University and Korea University. For high accuracy of the proposed model, it considers data classification, image processing, ratio adjustment of no-rain data. Rainfall prediction data were compared with minutely rainfall data at rain gauge stations close to image sensors. It indicates that the proposed model could offer an interpolation of current rainfall observation system and have large potential to fill an observation gap. Information from small-scaled areas leads to advance in accurate weather forecasting and hydrological modeling at a micro scale.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1356-1362
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• 2005

The purpose of this study os to investigative the effect of Carrageenan-Induced Pain on lower limb muscle and ligament of rat. To evaluate pain mechanism in muscle and ligament, pain was induced by the injection of 2% $0.1m{\ell}$ carrageenan into the left lower limb muscle of rats after rats were anesthesized with 3% enflurane. Rats were killed on 72 hours after pain induction under the anesthesia. anterior rectus femoris muscle and its ligament were removed from rat hind limb. Morphological changes of them were peformed by the observation of light and electron microscopes. In the light microscopic findings, the muscle cells were polyheadral and situated with each other without small gap in control group. nucleus of cell was seen along the cell margin, and muscle cell groups were divided by regular narrow gap in cross section. In the pain-induced group, muscle cell groups were divided each other by the irregular gap, and some of groups formed larger than other cell groups by the fusion. Intercellular gap of most cell groups were increased compared with control groups. And also, perimysium of muscle cell groups was swollen in cross section. In control group, muscle cells contacted each other closely and each cell was divided by perimysium. The intracellular gaps were not seen between myofibrills, and also striations were well defined between muscle cells in longitudinal section. In pain-induced group, muscle cells were divided by the small intracellular gaps. And also, muscle cell showed many a short cross or longitudinal intercellular gaps in longitudinal section. In light microscopic findings of control group, tendon was composed with many tendon fibers contacted each other closely without gap. The free margin of tendon was fused, and apso the tendon fibers did not invaded between muscles. In pain-induced group, tendon was divided small groups by intertendinous gap, and also the margin of tendon divided by small groups. In the free margin, tendon invaded into muscle cells, and also fibroblasts between tendon fibers were long and lance-shaped. From these results, it is suggested that pain induction by carrageenan injured rat skeletal muscle and ligament by the morphological changes.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.6
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• pp.791-799
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• 2000

Statement of problem. Targis/Vectris restorations provide excellent esthetics. Marginal accuracy is significantly influenced by the preparation design. There were no studies to examine the effect of preparation design on the marginal discrepancy and fracture strength of Targis / Vectris crowns. Purpose. This study evaluated the marginal accuracy before and after cementation, and the fracture strength of FRC/Ceromer(Targis / Vectris) crowns according to different preparation design. Material and method. Three metal dies with different convergence angles($6^{\circ},\;10^{\circ},\;15^{\circ}$) were prepared. Total 30 (10 for each angle) Targis/Vectris crowns were made. The restorations were evaluated for adaptation of the margin before and after cementation, then were compressively loaded to failure. Fracture surfaces of the crowns were examined using a SEM. Results. The mean marginal gap was $49{\yen}m\;for6^{\circ},\;55{\S}>for\;10^{\circ}\;and\;70{\S}>for\;15^{\circ}$ and in clinically acceptable level. The mean marginal gap increased significantly after cementation. The increasing amount during cementation was the largest in the $6^{\circ}$ group. The crowns on 60 convergence angle had a significantly higher fracture strength than the crowns on $15^{\circ}$ angle. Mean fracture strength of total crowns regardless of convergence angle was 1390 N, which was higher than all-ceramic crowns. SEM observation showed two-mode fracture pattern. Conclusion. From the results of this study, all of the FRC/Ceromer crowns had clinically acceptable marginal accuracy and could withstand the bite force. Moreover, less convergent angle than all-ceramic crown might be recommended for preparation procedure.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.399-406
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• 2013

Reports about the intrusion of a natural tooth bounded by implants are very rare, although some concerns have been discussed on the intrusion of teeth connected to implants. A female aged 56 years received an implant (mandibular right first premolar) and post/core onto root rest (mandibular right second premolar) and was restored by single zirconia crown, respectively. Molars were implant restorations. Four month after loading, second premolar was intruded and prominent gap was shown between opposite tooth. Because nonspecific discomfort was expressed, observation was decided after explanation of prognosis of tooth without treatment. Three month later reversal to original position was detected on the periapical radiographs and fully recovered position with intimate contact was completed 11 more months later. Till now 2 years and 3 month observation is being performed. Through the observation of spontaneous recovery of a natural tooth bounded by implants, the cause of intrusion and a mechanism of spontaneous recovery could be estimated.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.221-221
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• 2022

Chromosome breakage occurred by DNA methylation inhibitor. Zebularine is known as DNA methylation inhibitor and suitable for water solubility among different DNA methylation inhibitors as 5-Azacytidine and 5-aza-2'-deoxycytidine. We used zebularine as mutagen according to different methods by roots absorption and seed imbibition. After zebularine treatment, DNA methylation inhibitor, we observed mitotic chromosome behavior what is different according to two different treatment methods. First, seed imbibition treatment in 1,000 μM of zebularine solution for 72 hours in dark conditions. The second treatment to seedlings of Keumkang was also treated in 1,000 μM of zebularine solution for 72 hours after germination. Root and shoot showed different elongations in each treatment. Root absorption treatment(3.01±0.48, 2.00±0.26) showed the shortest elongation in root and shoot than control(8.16±0.61, 4.03±0.48) and seed imbibition treatment(4.33±0.80, 2.48±0.36). It can be explained root tip meristematic cell activity was damaged by DNA methylation inhibitor. Primary root tips were collected in DW for 24 hours at low temperature(0℃) and fixed in fixation solution for 3 days to chromosome observation in mitosis. Mitotic index, chromosome structure and chromosome aberration were observed by phase-contrast microscope. Mitotic index of the control(0.29) showed twice mitotic cells as the treated groups(imbibition 0.15, absorption 0.14). Observation of chromosomes showed some short chromosomes and loosen chromosomes affected by zebularine. It is considered because of zebularine damage DNA in mitosis. We observed "gap by chromosome breakage" in chromosomes that have loose parts between centromere and telomere. It seems demethylation of zebularine occurs chromosome breakage.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.239.2-239.2
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• 2015

Graphene is a most interesting material due to its unique and outstanding properties. However, semi-metallic properties of graphene along with zero bandgap energy structure limit further application to optoelectronic devices. Recently, many researchers have shown that band gap can be induced in the Bernal stacked bilayer graphene. Several methods have been used for the controlled growth of the Bernal staked bilayer graphene, but it is still challenging to control the growth process. In this paper, we synthesize the large area Bernal stacked bilayer graphene using multi heating zone low pressure chemical vapor deposition (LPCVD). The synthesized bilayer graphenes are characterized by Raman spectroscopy, optical microscope (OM), scanning electron microscopy (SEM). High resolution transmission electron microscopy (HRTEM) is used for the observation of atomic resolution image of the graphene layers.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.31-36
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• 2001

As a part of micro engine development feasibility estimation was done through fabrication and test of down scaled combustor and MEMS fabricated spark electrode. In an experimental observation of the down scaled combustion phenomena where flame propagation was observed by optical method and pressure change in combustor which gives the information about the reaction generated thermal energy was recorded and analyzed. Optimal combustor scale was derived to be about 2mm considering increased heat loss effect and thermal energy generation capability. Through the fabrication and discharge test of MEMS electrode effects of electrode width and gap was investigated. Electrode was fabricated by thick PR mold and electroplating. From the result discharge voltage characteristic in sub millimeter scale electrode having thickness of $40{\mu}m$ was obtained. From the result base technology for design and fabrication of micro engine was obtained.

• Korean Journal of Veterinary Service
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• v.28 no.1
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• pp.23-30
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• 2005

Ethylene glycol (EG) intoxication in dogs can pose a diagnostic challenge. We investigated the effect of a lethal dose of EG to the Shepherd on blood, urine test, and histopathologic observation. Shepherds were treated orally with EG at $10\;m{\ell}/kg$ body weight. Clinically, EG caused the vomition, depression of central brain. Anion gap was increased, which was decreased pH of blood, The blood osmorality was increased at 3 hours, and BUN and creatinine was increased at 24 hour significantly. The pH of urine decreased. The crystal of calcium oxalate appeared at 6 hours. The amount of crystals increased at 12 and 24 hours. Microscopically, the degeneration of proximal tubules were shown at 1 hour and finally progressed as acute tubular nephrosis at 24 hours. These results suggest that the blood and urine test accompanied with histopathological examination be helpful to investigate the EG intoxication.

• 전기의세계
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• v.26 no.3
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• pp.76-83
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• 1977

The choice of control method and circuit must be decided after a broad inspection with the characteristics of load and control elements as well as that of electric and mechanical nature. In the present study, Pulse width modulated(PWM) SCR chopper was chosen and for the electric commutation, Jones' forced method was taken bacause of its having enough reverse bias energy. Objectives of experimentation by this system are; 1) the condition of SCR as a gate trigger pulse. 2) the observation of phenomena at the time of forced commutation 3) the experimentation on characteristics of speed control by PWM chopper. Above experimentation shows good characteristics, however, in the limit of narrow gap between the ON and OFF pulses, a complete control was not possible. So, that must be the point to be studied further alone with the harmonics influence.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.8-11
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• 1996

In one VTR(Video Tape Recorder), two or more heads are used to record or reproduce video signals. To obtain a uniform quality of a VTR, video heads should have similar charcteristics such as geometrical shapes and electro-magnetic performances. This research is aimed to develop a visual inspection system that can measure four geoemtrical parameters;HO, HI, Tw and Cw. To obtain a high realable results, DSP based image board and target based image processing algorithms were used. A series of experiments was performed for one thousands of video heads. From observation of the experimental results, the system is found to show good performance for inspection of video heads.