• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.262-267
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• 2011

The denaturing high performance liquid chromatography(DHPLC) with fluorescence detector assay is very useful tool for detecting nucleic acids. Furthermore, loop-mediated isothermal amplification(LAMP) constitutes a potentially valuable tool for rapid diagnosis of pathogenic microorganisms. In this study, we evaluated the specificity, detection limit, and sensitivity of a LAMP method and DHPLC method for rapid detection of the hepatitis b virus(HBV). As a result, the LAMP assay reported here has the advantage of rapid detection whereas, DHPLC assay has more sensitivity than other assays. These findings suggest that LAMP and DHPLC assay may be good tool for rapid diagnosis of clinical HBV infection.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.744-758
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• 2021

This study is aimed at identifying the possibility and effectiveness of teaching methods education for professors through the development of online teaching content and providing important implications for future online teaching content development and utilization strategies by looking at the differences in the experience and needs of professors who have taken online teaching content. A university surveyed 83 professors who took the seven teaching contents developed between 2015 and 2018, and took them from 2017 to 2019. As a result of the study, professors often took online teaching content for self-development purposes, were satisfied with the overall content, and cited the low psychological burden and resistance of education through personal learning, and the possibility of repeated learning online. The differences between importance and execution in content composition, the areas of statistically significant difference were easy-to-understand delivery, appropriate and sufficient examples, interest and motivation, facilitating interaction between learners, appropriate difficulty, reflection of current trends, appropriate presentation order and ethical composition. The importance level recognized by professors in the area was higher than execution level. In conclusion, opinions for improving online teaching content were appropriate and sufficient examples in the area of content composition, interest and motivation, and reflection of the latest trends. In the area of ease of use, there was stable playback, relay function, and location-independent.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.4
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• pp.427-436
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• 2017

The purpose of this study was to examine guardian's attitudes toward behavior guidance techniques used in pediatric dentistry. In this study, 117 guardians participated and the several behavior guidance techniques being used during actual pediatric dental treatment were explained to the guardians prior to writing a questionnaire. The behavior guidance techniques explained were: tell-show-do, voice control, protective stabilization by device, protective stabilization by staff, nitrous oxide sedation, sedation, and general anesthesia. For analysis, 106 completed survey forms were selected. Tell-show-do was rated as the most acceptable technique, followed (in order of decreasing acceptance) by: voice control; protective stabilization by staff; nitrous oxide sedation; protective stabilization by device; sedation; general anesthesia. Acceptance of each behavior guidance technique was not related to guardian age, gender, patient age, patient gender, patient dental experience, type of visit, and position of doctor. Within the limit of this study, the communicative guidance techniques (tell-show-do, voice control) were more acceptable than advanced behavior guidance techniques (protective stabilization, sedation, general anesthesia). The acceptability of general anesthesia was the lowest. The results of this survey may contribute to maintain optimal dentist - guardians communication in pediatric dentistry.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.138.1-138.1
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• 2011

천상열차분야지도와 소주천문도는 전통 별자리를 돌에 새긴 한국과 중국의 대표 천문도이다. 이들 천문도는 조선 초기인 1395년과 남송시대인 1247년에 각각 만들어졌다. 비슷한 시기에 만들어진 두 천문도에는 한양(漢陽)과 개봉(開封)의 위도를 기준으로 밤하늘에 보이는 동양의 전통 별자리가 새겨져있다. 본 연구에서는 이들 두 천문도의 별자리를 비교 분석하여 각각의 특징을 찾아내고 이들을 한국과 중국의 전통 별그림과 비교하였다. 천상열차분야지도 별그림의 가장 큰 특징은 밝기에 따라 별의 크기를 다르게 새긴 과학적인 표현법이다. 이 외에도 한국과 중국 석각천문도의 별그림에는 몇 가지 차이점이 있다. 두 천문도에서 보이는 별그림의 차이를 조사한 결과 다르게 그려진 별그림에서 각각의 공통된 특징을 찾아냈다. 두 천문도의 대표적 차이점은 별자리 연결방식과 별의 상대적 위치 차이에 의한 별자리 모양이다. 아울러, 두 천문도에 그려진 서로 다른 별그림을 한국과 중국의 보천가(步天歌)와 신의상법요(新儀象法要)의 별그림과 비교하였다. 한국과 중국의 석각 천문도를 비교한 결과 두 천문도 별그림의 가장 큰 차이점은 천문도 제작의 완성도와 별그림의 유래 그리고 별자리 표현 방식의 차이에서 기인하고 있음을 확인하였다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.299-306
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• 2003

본 논문에서는 현재 사용되고 있는 소수성 검정 알고리즘의 효율성을 비교하여 효과적인 알고리즘 사용에 관한 방향을 제시하려 한다. 현재 가장 일반적으로 사용하고 있는 Miller-Rabin 소수성검정법(Miller-Rabin primality test)에 대하여, Miller-Rabin 소수성 검정법 이외에 다른 확률적 소수성 검정법으로 제안된 Frobenius-Grantham 소수성 검정법(Frobenius-Grantham primality test) 이 있다. 그러나 합성수 판별에 대한 확률적 우세함에도 불구하고, Miller-Rabin 소수성 검정법을 대체하고 있지 못하는 이유는 시간복잡도(time complexity)가 Randomized polynomial time이기 때문에 같은 확률에 대한 평균 실행 속도가 Miller-Rabin 소수성 검정법보다 크게 효율적이지 못하기 때문이다. 또한, 2002년 Manindra Agrawal이 제시한 AKS 알고리즘(AKS algorithm)은 최초의 다항식 시간내 결정적 소수성 검정법(Polynomial time deterministic primality test)이지만, 시간 복잡도에서 다항식의 차수가 높기 때문에 현재 사용되고 있는 확률적 소수성 검정법(Probabilistic primality test)을 대체하지 못할 것으로 사료된다. 본 논문에서는 최근 발표된 소수성 검정법인 Frobenius-Grantham 소수성 검정법, AKS 알고리즘과 기존의 Miller-Rabin 소수성 검정법의 장단점을 비교·분석해 보고자 한다.

• Progress in Medical Physics
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• v.10 no.1
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• pp.33-40
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• 1999

Purpose: To simulate and measure the signal intensity of various tissues near bone interface in 2D and 3D neurological MR images. Materials and Methods: In neurological proton density (PD) weighted images, every component in the head including cerebrospinal fluid (CSF), muscle and scalp, with the exception of bone, are visualised. It is possible to acquire images in 2D or 3D. A 2D fast spin-echo (FSE) sequence is chosen for the 2D acquisition and a 3D gradient-echo (GE) sequence is chosen for the 3D acquisition. To find out the signal intensities of CSF, muscle and fat (or scalp) for the 2D spin-echo(SE) and 3D gradient-echo (GE) imaging sequences, the theoretical signal intensities for 2D SE and 3D GE were calculated. For the 2D fast spin-echo (FSE) sequence, to produce the PD weighted image, long TR (4000 ms) and short TE$_{eff}$ (22 ms) were employed. For the 3D GE sequence, low flip angle (8$^{\circ}$) with short TR (35 ms) and short TE (3 ms) was used to produce the PD weighted contrast. Results: The 2D FSE sequence has CSF, muscle and scalp with superior image contrast and SNR of 39 - 57 while the 3D GE sequence has CSF, muscle and scalp with broadly similar image contrast and SNR of 26 - 33. SNR in the FSE image were better than those in the GE image and the skull edges appeared very clearly in the FSE image due to the edge enhancement effect in the FSE sequence. Furthermore, the contrast between CSF, muscle and scalp in the 2D FSE image was significantly better than in the 3D GE image, due to the strong signal intensities (or SNR) from CSF, muscle and scalp and enhanced edges of CSF. Conclusion: The signal intensity of various tissues near bone interface in neurological MR images has been simulated and measured. Both the simulation and imaging of the 2D SE and 3D GE sequences have CSF, fat and muscle with broadly similar image intensity and SNR's and have succeeded in getting all tissues about the same signal. However, in the 2D FSE sequence, image contrast between CSF, muscle and scalp was good and SNR was relatively high, imaging time was relatively short.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.1
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• pp.1-11
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• 2018

Mapping accurate spatial information is important for constructing three-dimensional (3D) spatial models and managing artificial facilities, and, especially, mapping road centerlines is necessary for constructing accurate road maps. This research developed a semi-automatic methodology for mapping road centerlines using the MMS(Mobile Mapping System) LiDAR(Light Detection And Ranging) point cloud as follows. First, the intensity image was generated from the given MMS LiDAR data through the interpolation method. Next, the line segments were extracted from the intensity image through the edge detection technique. Finally, the road centerline segments were manually selected among the extracted line segments. The statistical results showed that the generated road centerlines had 0.065 m overall accuracy but had some errors in the areas near road signs.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.111-115
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• 2012

In this paper, the thermal conductivities of ethylene glycol. based ZnO nanofluids manufactured using the pulsed wire evaporation method are experimentally measured using the transient hot wire method at temperatures in the range of $10^{\circ}C$ to $50^{\circ}C$. For this purpose, ethylene glycol.based ZnO nanofluids with 1%, 3%, and 5.5% volume fractions were manufactured using the pulsed wire evaporation method. Transmission electron microscopy (TEM) was performed to investigate the suspension stability of the ethylene glycol.based ZnO nanofluids. Based on the experimental results, the thermal conductivities of ethylene-glycol-based ZnO nanofluids increase with increasing volume fractions of ZnO nanofluids. The maximum enhancement of the thermal conductivity is 26.5% for a volume fraction of 5.5% at $22^{\circ}C$. Finally, the experimental results are compared with conventional models such as the Maxwell and Hasselman & Johnson models.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.169-175
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• 1976

A solvent extraction-atomic absorption spectrophotometry for determination of trace amount of cadmium, copper, lead and zinc and a flameless atomic absorption spectrophotometry for mercury in sea water were studied. The optimum pH range for solvent extraction was pH 4-7. A better solvent extraction efficiency was obtained with MIBK solvent than nitrobenzene, benzene, isoamylalcohol, n-buthylacetate. DDTC was more advantageous than APDC as chelating agent. The metals, chelated with DDTC and concentrated into MIBK by solvent extraction with a volume of $1\iota$ of sea water for cadmium, copper and lead, and 200m1 for zinc, were determined simultaneously by atomic absorption spectrophotometry. For mercury determination, 500ml of sea water was digested with permanganate-sulfuric acid and mercury( II ) was reduced by stannous chloride and aerated the solution with air pump until the absorbance reached a constant value. The precisions, in standard deviation, of these methods were 0.058ppb for cadmium, 0.084 ppb for copper, 0.44ppb for lead, 2.49ppb for zinc and 0.08 ppb for mercury. The sensitivities, expressed in $ppb/1\%$ absorption, were 0.058 ppb cadmium, 0. 15 ppb copper, 0.6 ppb lead, 1.2 ppb zinc and 0.01 ppb mercury respectively. No significant adsorption on the wall of polyethylene sample bottle occurred during 30 days of storing by acidification to pH 1.5 with nitric acid except zinc. Poor reproducibility was found for zinc with this method.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.1
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• pp.57-63
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• 2021

In this study, isoscoparin was selected as an indicator component to develop Silene seoulensis extract as a functional cosmetic material, and we developed an analysis method using high performance liquid chromatography (HPLC) for quality control. HPLC was performed on a Unison US-C18 with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and methanol at a flow rate of 1.0 mL/min at 35 ℃, and the detection wavelength was 330 nm. The HPLC method was performed in accordance with the international conference on harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation were 0.02 and 0.07 mg/mL respectively. Calibration curves showed good linearity (R2 > 0.99988), and the precision of analysis was satisfied (less than 0.46%). In addition, the recovery rate was in the range of 99.10 to 101.61%, it was shown to be accurate. This result indicated that the established HPLC method is very useful for the determination of marker compounds in Silene seoulensis extracts.