• 한국환경보건학회지
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• 제45권6호
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• pp.594-604
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• 2019

Objectives: This study developed and validated an analysis method of urinary metals and metalloids that can be applied inductively with coupled plasma mass spectrometry (ICP-MS). Methods: 0.3 mL of urine was used to analyze 25 metal and metalloid compounds using ICP-MS. The validation of the analytical method included linearity, accuracy, precision, and the calculation of detection limits. In addition, a comparison test was performed with the graphite furnace atomic absorption spectrometry (GF-AAS) method, which is the current standard method, with urine samples of 66 healthy subjects. Results: The linearities (R²) of calibration curves of all 25 compounds were ≥ 0.999. Of the 25 compounds, the intra-day and inter-day accuracy% of 17 and 20 met ≤15%, respectively. In addition, fifteen compounds showed ≤15% recovery% for certificated reference materials. Intraclass correlation coefficients of the comparison between the current methods and new methods in this study were 0.952 (p-value<0.001) and 0.911 (p-value<0.001) for urinary cadmium and mercury, respectively. Conclusion: This study proposes an efficient simultaneous methodology that can analyze multi elements in smaller sample amounts. More reproduction experiments are needed in the future.

• Imaging Science in Dentistry
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• 제48권2호
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• pp.121-125
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• 2018

Purpose: Detecting laryngeal cartilages (triticeous and thyroid cartilages) on panoramic radiographs is important because they may be confused with carotid artery calcifications in the bifurcation region, which are a risk factor for stroke. This study assessed the efficiency of panoramic radiography in the diagnosis of calcified laryngeal cartilages using cone-beam computed tomography (CBCT) as the reference standard. Materials and Methods: A total of 312 regions(142 bilateral, 10 left, 18 right) in 170 patients(140 males, 30 females) were examined. Panoramic radiographs were examined by an oral and maxillofacial radiologist with 11 years of experience. CBCT scans were reviewed by 2 other oral and maxillofacial radiologists. The kappa coefficient(${\kappa}$) was calculated to determine the level of intra-observer agreement and to determine the level of agreement between the 2 methods. Diagnostic indicators(sensitivity, specificity, accuracy, and false positive and false negative rates) were also calculated. P values <.05 were considered to indicate statistical significance. Results: Eighty-two images were re-examined to determine the intra-observer agreement level, and the kappa coefficient was calculated as 0.709 (P<.05). Statistically significant and acceptable agreement was found between the panoramic and CBCT images (${\kappa}=0.684$ and P<.05). The sensitivity, specificity, diagnostic accuracy rate, the false positive rate, and the false negative rate of the panoramic radiographs were 85.4%, 83.5%, 84.6%, 16.5%, and 14.6%, respectively. Conclusion: In most cases, calcified laryngeal cartilages could be diagnosed on panoramic radiographs. However, due to variation in the calcifications, diagnosis may be difficult.

• 복식
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• 제64권8호
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• pp.67-82
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• 2014

This research aims to explicate how we reveal our identity and emphasize beauty in our passion for beauty. It also attempts to find out our sense of beauty in exaggeration of visual expressions. The purpose is to represent how the contemporary knit fashion is various and exaggerated in our modern fashion world, and also to give the direction of new knitwear designs through the visual analysis of exaggerated knit fashion. Literature research was done by studying reference books and magazines, leading papers and based on a dissertation thesis. This study collected 787 designer's works published in the world's big Four collections from the 2000 S/S to 2011 S/S, in 23 seasons during 12 years. In answer to 9 experts about the criteria of classification, 520 works were chosen and analyzed according to the standard of exaggerated knitwear. The result of the study is the followings: The type of exaggeration shown in contemporary knit fashion was classified in three categories; Enlarge exaggeration, reduce exaggeration and transform exaggeration. As a sub-category, enlarge exaggeration was classified into three categories; Volume expansion and the expansion by the material, gauge and larger composition application expansion. Reduce exaggeration appeared as mini-reduction, skinny-reduction and transform exaggeration was respectively classified into deformation of the shape and patterns. The characteristics of exaggeration shown in contemporary knit fashion appeared as the new formative sense. In terms of fuller sense and surface, using various materials, gauge, changes in the composition represented challenges for textiles. The exaggerated contemporary knitwear expressed sex appeal using tight-fitting effect. Contemporary knit fashion simplified the design by taking advantage of the strong elastic attributes. It showed the beauty of women, expressed variability and limitless knit characteristics beyond the conventional thinking. In addition, it has been well represented as a form of freedom, amusement and diversity.

• 정보교육학회논문지
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• 제10권3호
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• pp.363-370
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• 2006

본 논문에서는 단위 수업 중 자료투입시기를 분석하여 초등학교 교육환경에 필요한 메타데이터 요소를 탐색하고 메타데이터 요소를 추출하여 국제적인 메타데이터 표준인 DC Core Education 의 메타데이터 표준안을 기반으로 하는 ICT 교수학습 자료 검색 및 활용을 위한 메타데이터 시스템을 개발하였다. 초등교육 현장에서 생성되는 다양한 ICT 교수학습 자료와 웹상에 존재한 양질의 교육 정보 자원들을 일반적인 수업 흐름인 도입, 전개, 정리의 메타데이터 요소를 추가하여 통합검색과 체계적인 인터페이스를 제공함으로써 초등학교 교사가 쉽고 편리하게 단위 수업에 유용한 것을 찾아내고 수업에 투입할 수 있다. 뿐만 아니라 향후 교수학습 자료를 수업에 직접 필요한 형태로 분류하여 제공하여 효율적인 교수학습 자료를 공유를 함으로써 ICT 활용 수업에 실제적인 도움을 줄 수 있을 것으로 기대된다.

• Nuclear Engineering and Technology
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• 제32권5호
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• pp.477-484
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• 2000

To estimate the degree of intake of $^{238}$ U and $^{232}$ Th through daily diet, a Korean mixed diet sample was prepared after the investigation of the amount of consumption of the daily diet which corresponds to the age of 20 to 60 years. For the analysis of U and Th, the RNAA method was applied. Two standard reference materials were used for quality control and assurance and the analytical results were compared with a certified value. The determination of U and Th in the Korean mixed diet sample was carried out under the same analytical conditions and procedures with SRM. It is found that the concentration of U and Th in a Korean mixed diet was about 35.4 ppb and 3.4 ppb. From these results, the daily intake of $^{238}$ U and $^{232}$ Th by diet is evaluated to be 6.98 and 0.67 $\mu\textrm{g}$ per day, respectively. Radioactivities related to the intake of $^{238}$ U and $^{232}$ Th were estimated to be about 86 mBq and 27 mBq per person per day and the annual dose equivalents from $^{238}$ U and $^{232}$ Th revealed as 3.18 $\mu$Sv and 0.29 $\mu$Sv per person, respectively.

• 한국측량학회지
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• 제32권4_1호
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• pp.327-333
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• 2014

도시 열 환경 개선을 위해서는 무엇보다도 특정지역의 열 환경에 대한 구조적 특성분석이 선행되어져 문제점을 분석하고 보완되어야 한다. 본 연구에서는 Landsat 위성을 활용하여 대구광역시의 1월과 8월의 열 환경의 중심성 측정, 분포도 작성, 공간통계 분석 등을 활용하여 공간적 특성에 따른 열 환경구조를 분석하였다. 분석을 위해 위성영상의 열적외밴드를 활용하여 표준정규분포화하여 점수로 중심성을 추출하였고, 국지적 공간에서의 자기 상관성을 파악하기 위한 국지적 모란지수(Local Local Moran's I)를 기초로 한 Cluster Map를 작성하여 환경공간구조의 분포 특성을 파악하였다. 따라서 위성영상을 활용한 열 환경 분포 특성과 중심지의 파악은 도시의 열 환경 개선 계획 및 관리방안을 모색하는데 필요한 중요한 기초자료로서 정부의 다양한 열환경 정책이나 계획에 우선시 되어야 할 참고자료를 제공하고자 한다.

• Bulletin of the Korean Chemical Society
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• 제13권6호
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• pp.620-624
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• 1992

The analytical performance of glow discharge mass spectrometer (GD-MS), using a flat type ion source is discussed. The efficiency of ion extraction was maximized at the distance between anode and cathode of 6 mm. At the operation condition of 4 mA, -1000 volt, and 1 mbar for the source, the optimum voltages for sampler and skimmer were40 volt and -280 volt, respectively. The intensities of Cu, Zn, and Mn were increased as a function of square root of current approximately. Korea standard reference materials (KSRM) were tested for an application study. The detection limits of most elements were obtained in the range of several ppm at the optimized operating condition. The peaks of aluminum and chromium were interfered by those of residual gases. The depth profile of nickel coated copper specimens (3, 5, 10 ${\mu}m$ thickness) were obtained by plotting time versus intensities of Ni and Cr after checking the thickness of nickel coated using a scanning electron microscope (SEM). At this moment, the sputtering rate of 0.2 ${\mu}m/min$ at the optimum operating condition was determined from the slope of the plot of time to the coating thickness. The roughness spectra of specimen's crater after 16 min, discharge were obtained using a Talysuf5m-120 roughness tester as well.

• The Journal of Advanced Prosthodontics
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• 제13권2호
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• pp.89-99
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• 2021

PURPOSE. This study aimed to compare the accuracy (trueness and precision) of interim crowns fabricated using DLP (digital light processing) according to post-curing time. MATERIALS AND METHODS. A virtual stone study die of the upper right first molar was created using a dental laboratory scanner. After designing interim crowns on the virtual study die and saving them as Standard Triangulated Language files, 30 interim crowns were fabricated using a DLP-type 3D printer. Additively manufactured interim crowns were post-cured using three different time conditions-10-minute post-curing interim crown (10-MPCI), 20-minute post-curing interim crown (20-MPCI), and 30-minute post-curing interim crown (30-MPCI) (n = 10 per group). The scan data of the external and intaglio surfaces were overlapped with reference crown data, and trueness was measured using the best-fit alignment method. In the external and intaglio surface groups (n = 45 per group), precision was measured using a combination formula exclusive to scan data (10C2). Significant differences in accuracy (trueness and precision) data were analyzed using the Kruskal-Wallis H test, and post hoc analysis was performed using the Mann-Whitney U test with Bonferroni correction (α=.05). RESULTS. In the 10-MPCI, 20-MPCI, and 30-MPCI groups, there was a statistically significant difference in the accuracy of the external and intaglio surfaces (P<.05). On the external and intaglio surfaces, the root mean square (RMS) values of trueness and precision were the lowest in the 10-MPCI group. CONCLUSION. Interim crowns with 10-minute post-curing showed high accuracy.

• Journal of the Korean Wood Science and Technology
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• 제32권5호
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• pp.45-50
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• 2004

현재 국내의 목구조 설계는 ASD (Allowable Structural Design)에 기초하여 이루어 지고 있다. 그러나 이 설계 방법은 재료의 변이와 설계에 따른 다양한 조건물을 충분히 고려하고 있지 못하고 있어 과설계의 원인이 되고 있다. 따라서 외국의 경우는 이를 극복하기 위하여 1990년 초반부터 확률론적인 접근을 통한 설계에 대한 연구가 꾸준히 진행되어 왔으며, 현재는 이에 기초한 설계 기준을 마련, 활용하고 있는 실정이다. 그러므로 본 연구에서는 국산재에 이러한 설계법을 도입하기 위하여 기존 연구에서 밝혀진 제재목과 집성재의 강도적 성능에 대한 분포 특성을 충분히 고찰하여 평균, 표준 편차, 분산, 변이 계수 동의 인자를 얻었고, 이를 통해서 국산낙엽송부재에 대해서 기존의 ASD 코드를 RBD (Reliability Based Design) 코드로 전환하여 기본적인 코드 전환 체계를 갖추고자 하였으며. RBD 코드로의 전환 시 따르게 되는 중요 변수 즉 시편 수에 대한 고찰을 하였다. 또한, 적어도 각 시편에 대해서 적어도 500개 이상의 반복수가 있어야만 어느 정도 정확한 값을 얻을 수 있음을 확인할 수 있었다.

• 한국식생활문화학회지
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• 제37권6호
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• pp.540-546
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• 2022

This study aimed to determine the changes in the vitamin B₅ content of raw and cooked vegetables. The nineteen vegetables were subjected to different cooking methods, viz. blanching, boiling, pan-broiling, and steaming. Vitamin B₅ was quantified by reversed-phase high-performance liquid chromatography (HPLC) using photodiode-array (PDA) detection (200 nm). The standard reference materials (SRM) were used to validate the accuracy of vitamin B₅ measurement method used in this study. The cooking yields ranged from 82.63 to 107.62% and decreased in most of the vegetables except bitter melon, curled mallow, and eggplant. The raw kabocha squash, Danhobak, had the highest vitamin B₅ content (0.671 mg/100 g) among the samples. All cooked vegetables showed lower vitamin B₅ content compared to the raw samples. The true retention ranged from 0% (crown daisy, blanching) to 84.49% (kabocha squash, steaming). These results indicate that vitamin B₅ is degraded after cooking. Pan-broiling and steaming are better cooking methods than the others for retaining vitamin B₅. The true retention of vitamin B₅ in the samples markedly depends on the cooking method and food matrix. These results can be used as important basic data for nutritional evaluation of meals.