• Imaging Science in Dentistry
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• v.39 no.1
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• pp.41-49
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• 2009

Purpose: To detect the progression of experimentally induced periapical lesions on periapical radiograph and cone beam computed tomograph (CBCT) by quantitative analysis. Materials and Methods: After the removal of coronal pulps from premolars of two Beagle dogs, the root canals of premolars were exposed to oral environment during one week and then sealed for 70 days. Digital periapical radiographs and CBCTs were taken at baseline and every 7 days for 77 days after pulp exposure. We examined occurrence and areas of periapical bone resorption. Three comparative groups of CBCT radiographs were prepared by average projection of thin slabs with different bucco-lingual thicknesses (0.1, 3.0, and 8.0 mm) using a 3D visualization software. Radiographic densities were compensated by image normalization. Digital images were processed with mathematical morphology operations. The radiographic density and morphological features of periapical lesions were compared among three groups of CBCT in different time points. Results: In the CBCT group with 0.1 mm thickness, radiographic density (p<0.05) and trabecular bone area (p<0.01) were significantly decreased at the fifth week. However, in the CBCT groups with 3 mm and 8 mm thickness and periapical radiographs, none of densitometric and morphological features showed any significant differences in different time points. Radiographic density of periapical lesion showed increasing tendency at the eleventh week after pulp exposure. Conclusion: Radiographic detection of periapical lesions was possible at the fifth week after pulp contamination by quantitative method and was affected by buccolingual bone thickness.

• Journal of Electrochemical Science and Technology
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• v.7 no.1
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• pp.68-75
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• 2016

In this study a new, simple, precise, accurate and economic electrochemical method was developed and validated for the voltammetric determination of zolpidem (ZP) using disposable pencil graphite (PG) electrode. The anodic oxidation of ZP on the surface of the PG electrode was examined in a britton robinson (BR) buffer. Square wave and cyclic voltammetry were used as electrochemical techniques in the potential range of 0-1.2 V in the pH 8 BR buffer. In cyclic voltammetry studies, the diffusion coefficient of ZP oxidation was found to be 3.6×10^-6 cm² s^-1. On the other hand, the ZP has shown a well-defined irreversible anodic peak at 0.98 V in the square wave voltammetry mode. The PG electrode, primarily being graphite which has a large active surface area gives rise to increasing peak current with respect to ZP electrooxidation. PG electrode showed an electrocatalytic effect in anodic oxidation of ZP. A linear relationship between catalytic current response and ZP concentration was obtained over a concentration range of 10-30 μM with R.S.D. values ranging from 0.29-3.89. Limits of detection and quantitation were found to be 1 and 3 μM, respectively. Finally, the PG electrode was successfully used to determine ZP in standard and tablet dosage forms with a mean recovery of 100.69 %.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.459-465
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• 2013

This paper presents a differential interferometry technique for soil moisture change detection by measuring surface-height variation. COSMO-SkyMed SAR images were used to verify the DInSAR(differential interferometric SAR) technique. The soil penetration depth changes according to soil moisture, that causes phase change of the received signal. The height of soil surface and its displacement can be detected by a radar interferometry technique using phase difference of two received signals. To retrieve displacement variation, one of three SAR images is used as a reference image. Reference image and other two images are processed by the differential interferometry technique in the same area. The soil moisture was measured for the test sites to verify the DInSAR technique. The penetration depth is calculated by using the in-situ measured soil moisture data and it is compared with the displacement values acquired by the DInSAR technique.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.82.2-82.2
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• 2017

Korea Microlensing Telescope Network (KMTNet) is one of powerful tools for investigating primordial objects in the inner solar system in that it covers a large area of the sky ($2{\times}2$ degree2) with a high observational cadence. The Deep Ecliptic Patrol of the Southern sky (DEEP-South) survey has been scanning the southern sky using KMTNet for non-bulge time (45 full nights per year) [1] since 2015 for examining color, albedo, rotation, and shape of the solar system bodies. Since 2017 January, we have launched a new collaborative group between Korea Astronomy and Space Science Institute (KASI) and Seoul National University (SNU) with support from KASI to reinforce mutual collaboration among these institutes and further to enhance human resources development by utilizing the KMTNet/DEEP-South data. In particular, we focus on the detection of comets and asteroids spontaneously scanned in the DEEP-South for (1) investigating the secular changes in comet's activities and (2) analyzing precovery and recovery images of objects in the NASA's NEOWISE survey region. In this presentation, we will describe our scientific objectives and current status on using KMTNet data, which includes updating the accuracy of the world coordinate system (WCS) information, finding algorithm of solar system bodies in the image, and doing non-sidereal photometry.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.21 no.4
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• pp.289-296
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• 2018

Purpose: We aimed to study the pattern of liver-injury in children with dengue fever (DF) and validate serum aminotransferase ${\geq}1,000IU/L$ as a marker of severe DF. Methods: Children admitted with DF were included. DF was defined by presence of clinical criteria and positive serological or antigen tests in absence of other etiology. DF severity was graded as dengue without or with warning signs and severe dengue. Liver-injury was defined as alanine aminotransferase (ALT) more than twice the upper limit of normal (boys, 30 IU/L; girls, 21 IU/L). Results: Of 372 children with DF, 144 (38.7%) had liver-injury. Risk of liver-injury and aminotransferase levels increased with DF severity (p<0.001). Recommended ALT and aspartate aminotransferase (AST) cut-off at ${\geq}1,000IU/L$ had sensitivity 4.8% (5/105), specificity 99.3% (265/267) for detection of severe DF. In children with ALT and AST <1,000 IU/L (n=365), the area under receiver operating curves for prediction for severe DF, were 0.651 (95% confidence interval [CI], 0.588-0.714; p<0.001) for ALT and 0.647 (95% CI, 0.582-0.712; p<0.001) for AST. Serum ALT at 376 IU/L and AST at 635 IU/L had sensitivity and specificity comparable to ${\geq}1,000IU/L$ for defining severe DF. Conclusion: Liver-injury is common in DF. The ALT and AST levels increase with DF severity. ALT and AST levels of ${\geq}1,000IU/L$ could be lowered to 376 IU/L and 635 IU/L respectively for defining severe DF.

• Journal of Preventive Medicine and Public Health
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• v.7 no.2
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• pp.327-332
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• 1974

Wells are perticularly able to be a source of water-borne infections disease in the army society. Owing to untreated drinking water, high indidence of water-borne diseases are encounted in Korea. This study was carried out to evaluate the physicochemical and bacteriological states of 298 wells in army camps around Daegu city during a year from January to November, 1974. Main findings are summerized as follows: 1. Turbidity, Colorness & odor was within normal range in all samples. 2. Reaction of pH, cnsumption of KMnO4, total hardness and chlorine ion as over almost within normal range. 3. Free Ammonia was detected to 33.2% positive, and nitrite, 45.5% positive. 4. In the bacteriological test 40.3% of all samples were over the standard limit on E. Coli. 5. In comparison of nitrate and E. Coli detection, 60.1% of nitrite was over the standard limit out of the positive cases detected E. Coli. and all of E. Coli were over the standard limit out of the positive cases of nitrite. 6. The contamination was very remarkable in the spring and summer, and very diminished in the autumn and winter.

• The Plant Pathology Journal
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• v.16 no.2
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• pp.110-117
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• 2000

Potato virus X (PVX-KO) showing mild mosaic and stunting symptoms on potato (Solanum tuberosum) in Kangwon area has been isolated and characterized. EM observation of the purified virus particles showed flexuous rod shape of about 520 nm in length. The coat protein (CP) of the virus had a molecular weight of 31 kDa in SDS-PAGE analysis, and the viral RNA was approximately 6.4 kb in size in denatured agarose gel electro-phoresis. In gel-immunodiffusion tests, it reacted strongly with an antiserum to common PVX from BIOREABAAG (USA). A rabbit antiserum was produced using purified virus and used for routine PVX detection by ELISA. Cultivated potatoes in Kangwon and other areas were frequently infected with PVX-KO. Both Datura stramonium and Nicotiana tabaccum cultivars developed necrotic local lesions 5 days after inoculation, and systemic mosaic symptoms with vein clearing 2 weeks after inoculation. All the features agree with the description of other PVX strains. To confirm and determine PVX strains, reverse transcription-polymerase chain reaction experiment was conducted using specific primers for viral CP. Amplified DNA fragments were cloned and sequenced. Results showed nucleotide sequence homologies of about 88 to 99% to other PVX strains. Based on CP amino acid sequence deduced from nucleotide sequences and host range studies PVX-KO is considered a member of the type X subgroup of PVX.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7141-7148
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• 2014

Background: Oral squamous cell carcinoma (OSCC) is an important malignancy throughout the world; early detection is an important criterion for achieving high cure rate. Out of the many reported markers for OSCC, this study validated the efficacy of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in differentially diagnosing premalignant oral lesions and OSCC. Also, the study aimed to correlate the levels of salivary and serum TNF-${\alpha}$ with clinicopathologic factors. Materials and Methods: A prospective experimental laboratory study was designed. Serum and salivary samples from 100 subjects in each group of healthy control, premalignant disease (PMD) and OSCC were collected for the study following appropriate exclusion and inclusion criteria. Serum and salivary level of TNF-${\alpha}$ was analysed by enzyme linked immunosorbent assay. The data obtained were subjected to appropriate statistical analysis. Results: Increased level of both serum and salivary TNF-${\alpha}$ was observed in OSCC subjects compared to healthy control and PMD group. Receiver operator characteristic curve analysis and area under curve values showed high specificity and sensitivity for salivary TNF-${\alpha}$ in differentiating OSCC from PMD and healthy controls. There was significant increase in TNF-${\alpha}$ level in moderately and poorly differentiated lesion compared to well differentiated lesion and in stage IV of clinical stage. A positive correlation was observed only with histological grading of OSCC and TNF-${\alpha}$. Conclusions: Salivary TNF-${\alpha}$ is proved to be superior for detecting OSCC. Increase in TNF-${\alpha}$ with histological grading and clinical staging suggests a role in prognosis.

• Journal of IKEEE
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• v.10 no.1 s.18
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• pp.40-48
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• 2006

This paper presents a new rooftop surface estimation method from 3D line segments. 3D rooftop surface estimation is based on the hierarchical grouping and initiated by 3D line merging for the disconnected 3D line segments. Merged 3D lines are applied to the detection of rooftop by surface estimating technique. To estimate surfaces we detect L-corner and T-corner points, and find fixed reliable junction points. The hypothesis of the possible rooftop surfaces are estimated as polygonal surfaces by these fixed junction points and building's rooftop models are generated by testing the possible surfaces in terms of assumptions of building surface properties. We carried out experiments by synthetic images on Avenches data set and the experimental results showed that we could reliably build 3D model with 3D surfaces, errors of which came up with 0.4 - 1.3 meter, 2.5 times more accurate than the elevation date from the conventional area-based stereo.

• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.75-80
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• 2003

In this paper, we designed add current scan system basically. Although NDT system using AC method in now days had problem with limit of detection rate and limit of device organization, in this paper, we made up these problem so that designed device smaller than system used, reduction of cost of system organization and precision of measuring crack. Also, AC leakage flux system had high accuracy about minute crack in the surface and advantage of designing system easily so that we designed system for concerning about crack of surface. Furthermore, it can be able to detect exact crack of reference in wide area by using DSP320C31 chip to reduce the time of measuring crack.