• Title/Summary/Keyword: 과학 전공

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Evaluation of repeated measurement stability of dentition type of maxillary anterior tooth: an in vitro study (상악 전치의 치열 형태에 따른 스캔 반복 측정 안정성 평가: in vitro 연구)

  • Park, Dong-In;Son, Ho-Jung;Kim, Woong-Chul;Kim, Ji-Hwan
    • Journal of Technologic Dentistry
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    • v.41 no.3
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    • pp.211-217
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    • 2019
  • Purpose: The purpose of this study is to evaluate the repeated measurement stability of scans related to dentition type. Methods: A normal model and the crowding and diastema models are also duplicated using duplicating silicon. After that, a plaster model is made using a plaster-type plaster on the duplicate mold, and each model is scanned 5 times by using an extraoral scanner. The gingival part and molar part were deleted from the 3D STL file data obtained through scanning. Using the 3D stl file obtained in this way, data is nested between model groups. Thereafter, RMS values obtained were compared and evaluated. The normality test of the data was performed for the statistical application of repeated measurements with dentition type, and the normality was satisfied. Therefore, the one-way ANOVA test, which is a parametric statistical method, was applied, and post-tests were processed by the Scheffe method. Results: The average size of each RMS in the Normal, Diastema, and Crowding groups was Normal> Crowding> Diastema. However, the standard deviation was in the order of Crowding> Normal> Diastema. The average value of each data is as follows. Diastema model was the smallest ($5.51{\pm}0.55{\mu}m$), followed by the crowding model ($12.30{\pm}2.50{\mu}m$). The normal model showed the maximum error ($13.23{\pm}1.06{\mu}m$). Conclusion: There was a statistically significant difference in the repeatability of the scanning measurements according to the dentition type. Therefore, you should be more careful when scanning the normal intense or crowded dentition than scanning the interdental lining. However, this error value was within the range of applicable errors for all clinical cases.

Comparison of three-dimensional adaptation as per the rinsing time of temporary crown manufactured using a digital light processing printer (디지털 광 조명 방식으로 제작한 임시 크라운의 세척 시간에 따른 3차원 적합도 평가)

  • Lee, Beom-Il;You, Seung-Gyu;You, Seung-Min;Kim, Ji-Hwan
    • Journal of Technologic Dentistry
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    • v.42 no.4
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    • pp.334-340
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    • 2020
  • Purpose: This study aimed to compare three-dimensional adaptation with the rinsing time of the temporary crown produced using the digital light processing method. Methods: The maxillary right first molar abutment was scanned with a dental scanner. A temporary crown was designed with the scanned abutment. The designed crown was made of 10 temporary crowns using a digital light processing printer. The crowns were divided into the 5-minute and 10-minute rinsing groups; 5 temporary crown washes were performed for each group. In order to obtain the internal data, each group was scanned for a temporary crown. The three-dimensional fit was measured by superimposing the scanned internal surface data and the abutment data. The average comparison of three-dimensional adaptation was analyzed using the Mann-Whitney U test. Results: The 5-minute rinsing group showed a significantly higher adaptation of 71.42±3.08 ㎛ as compared to the 10-minute rinsing group (67.52±0.92 ㎛) (p<0.05). Conclusion: When making a temporary crown with a digital light processing method, a rinsing time of 10 minutes is appropriate.

Revisit the Cause of the Cold Surge in Jeju Island Accompanied by Heavy Snow in January 2016 (2016년 1월 폭설을 동반한 제주도 한파의 원인 재고찰)

  • Han, Kwang-Hee;Ku, Ho-Young;Bae, Hyo-Jun;Kim, Baek-Min
    • Atmosphere
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    • v.32 no.3
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    • pp.207-221
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    • 2022
  • In Jeju, on January 23, 2016, a cold surge accompanied by heavy snowfall with the most significant amount of 12 cm was the highest record in 32 years. During this period, the temperature of 850 hPa in January was the lowest in 2016. Notably, in 2016, the average surface temperature of January on the Polar cap was the highest since 1991, and 500 hPa geopotential height also showed the highest value. With this condition, the polar vortex in the northern hemisphere meandered and expanded into the subtropics regionally, covering the Korean Peninsula with very high potential vorticity up to 7 Potential Vorticity Unit. As a result, the strong cold advection, mostly driven by a northerly wind, around the Korean Peninsula occurred at over 2𝜎. Previous studies have not addressed this extreme synoptic condition linked to polar vortex expansion due to the unprecedented Arctic warming. We suggest that the occurrence of a strong Ural blocking event after the abrupt warming of the Barents/Karas seas is a major cause of unusually strong cold advection. With a specified mesoscale model simulation with SST (Sea Surface Temperature), we also show that the warmer SST condition near the Korean Peninsula contributed to the heavy snowfall event on Jeju Island.

Evaluation of marginal and internal fit of metal copings fabricated by selective laser melting (SLM 방식으로 제작한 도재관 금속하부구조물의 변연 및 내면 적합도 평가)

  • Sung-Ryung Bae;Ha-Bin Lee;Mi-Jun Noh;Ji-Hwan Kim
    • Journal of Technologic Dentistry
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    • v.45 no.1
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    • pp.1-7
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    • 2023
  • Purpose: To evaluate the marginal and internal fit of metal coping fabricated by a metal three-dimensional (3D) printer that uses selective laser melting (SLM). Methods: An extraoral scanner was used to scan a die of the prepared maxillary right first molar, and the coping was designed using computer-aided design software and saved as an stereo lithography (STL) file. Ten specimens were printed with an SLM-type metal 3D printer (SLM group), and 10 more specimens were fabricated by casting the castable patterns output generated by a digital light processing-type resin 3D printer (casting the 3D printed resin patterns [CRP] group). The fit was measured using the silicon replica technique, and 8 points (A to H) were set per specimen to measure the marginal (points A, H) and internal (points B~G) gaps. The differences among the groups were compared using the Mann-Whitney U-test (α=0.05). Results: The mean of marginal fit in the SLM group was 69.67±18.04 ㎛, while in the CRP group was 117.10±41.95 ㎛. The internal fit of the SLM group was 95.18±41.20 ㎛, and that of the CRP group was 86.35±32 ㎛. As a result of statistical analysis, there was a significant difference in marginal fit between the SLM and CRP groups (p<0.05); however, there was no significant difference in internal fit between the SLM group and the CRP group (p>0.05). Conclusion: The marginal and internal fit of SLM is within the clinically acceptable range, and it seems to be applicable in terms of fit.

Eleven previously unrecorded fungal species isolated from hyphosphere soil supporting wild mushrooms in Jeju Island (제주도 야생버섯 hyphosphere 토양에서 분리된 국내 미기록 진균 11종 보고)

  • Hyeongjin Noh;Ye In Kim;Dong Hyeung Lee;Pyung Yeol Ko;Hye Sung Park;Kang-Hyo Lee;Seong Hwan Kim
    • Journal of Mushroom
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    • v.21 no.4
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    • pp.228-240
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    • 2023
  • To understand microorganism effects on wild mushroom fruiting bodies, we investigated the fungi in hyphosphere soil supporting wild mushroom species Cortinarius violaceus, Amanita hemibapha, Laccaria vinacelavellanea, and Amanita verna found in the Gotjawal area of Jeju Island. Fungal species identification based on morphological traits and molecular analysis of ITS, LSU rDNA, and β-tubulin gene sequences resulted in isolation and identification of eleven fungal species previously unrecorded in Korea. These newly-recorded species are: Arthrinium kogelbergensis, Kalmusia longisporum, Keithomyces carneum, Neopyrenochaeta cercidis, Penicillium ranomafanaense, Phomatodes nebulosa, Pyrenochaeta nobilis, Tolypocladium album, Talaromyces kendrickii, Talaromyces qii, and Umbelopsis gibberispora, and their morphological characteristics and phylogenetic positions are described.

The Mediating Effects of Major Satisfaction in the Relationship of Nursing Professionalism and Career Preparation Behavior in Nursing Students (간호대학생의 간호전문직관과 진로준비행동의 관계에서 전공만족도의 매개효과)

  • Park, Hyeon-MI;Seok, Ja-Yeong;Park, So-Yeon;Lee, So-young
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.5
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    • pp.1151-1158
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    • 2020
  • The purpose of this study was to examine the mediating effects of perceived nursing professionalism and career preparation behavior on the effects of major satisfaction of nursing students. For this purpose, 231 nursing students from 4 university in 4 city were sampled for convenience. The result of this study were as follows:First, nursing professionalism of nursing students directly affected career preparation behavior and major satisfaction, which was statistically significant. Second, nursing professionalism showed mediating effects in relationship between career preparation behavior. Third, the major satisfaction of nursing students directly affected nursing professionalism and career preparation behavior. Based on the results of the research, it is necessary to develop an intervention program that strengthen major satisfaction of nursing students.

Enhanced Macrophage Stimulatory Activities of Extracts from Kimchi Lactic Acid Bacteria-Fermented Mixed Herbal Medicines (김치 유산균 발효 혼합생약재 추출물의 강화된 대식세포 활성)

  • Gaeuleh, Kim;Hyun Young, Shin;Se Bin, Jeong;Eun Ji, Ha;Eun-Jin, Jeong;Ji-Young, Shin;Kwang-Won, Yu
    • The Korean Journal of Food And Nutrition
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    • v.35 no.6
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    • pp.399-410
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    • 2022
  • To enhance the bioavailability and bioactivities of mixed herbal medicines (RW), they were fermented with lactic-acid bacteria isolated from kimchi into postbiotics (FRW). Then, from the results of the 16s rRNA sequencing analysis, lactic acid bacteria isolated from kimchi were identified to be of two species, namely Lactobacillus sakei and Leuconostoc mesenteroides. The FRW prepared from the RW were extracted using hot water (HW) and 70% EtOH (EtOH) for comparison of their macrophage-stimulating activities. Based on a comparison of the activities of the FRW extracts, nitric oxide (NO) production of HW was significantly higher than that in EtOH. An analysis of the chemical properties of the extracts showed that HW had higher contents of neutral sugar and uronic acid than EtOH as well as contained a large amount of glucose. In addition, crude polysaccharide (CP) was prepared to enhance the macrophage-stimulating activity. The FRW-CP not only secreted immunostimulatory mediators but also increased the expression of immunostimulatory genes (iNOS, TNF-α, MCP-1, and IL-6). The fractionated FRW-CP contained about 90% neutral sugars, and these sugars were mainly composed of glucose, galacturonic acid, and arabinose. Thus, FRW prepared by fermentation of RW with kimchi lactic acid bacteria were found to be immunostimulatory modulators.

The Influence of Perception of Strength and Academic Self-Efficacy on Major Satisfaction of Nursing College Students (간호대학생의 강점인식과 학업적 자기효능감이 전공만족도에 미치는 영향)

  • Hyun-Jin Kim;Woo-Young Chae
    • Journal of the Korean Applied Science and Technology
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    • v.41 no.1
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    • pp.138-148
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    • 2024
  • The purpose of this study is a descriptive research study to confirm the relationship between perception of strength, academic self-efficacy and major satisfaction of nursing college students and to identify factors influencing major satisfaction. The subjects of this study were 172 nursing college students located in G City, and data collection was conducted from November 7 to December 21, 2022. The collected data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients and multiple regression analysis using SPSS/WIN 28.0 program. As a result of the study, major satisfaction had a significant positive correlation with perception of strength (r=.31, p<.001) and academic self-efficacy (r=.62, p<.001). Factors affecting major satisfaction of nursing college students were academic self-efficacy (𝛽=.53, p<001.) and advice from others as motivation of choosing major (𝛽=-.20, p=.002), which explained 42.6% of variance. The results of this study will be useful used to develop strategies to improve the major satisfaction of nursing college students. In the future, a follow-up study that can expand the subjects and explain the major satisfaction of nursing college students is suggested.

역사속 과학인물 - 영국 조셉 니덤(1900~1995)

  • Park, Seong-Rae
    • The Science & Technology
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    • v.29 no.7 s.326
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    • pp.90-92
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    • 1996
  • 영국의 과학자로 중국과학사를 연구해 위대한 업적을 남기고 작년, 95세를 일기로 타계한 조셉 니덤. 케임브리지대서 생화학을 전공한 그는 29세에 스탠포드대 교수가 되는 등 세계적 생화학자로서 명성을 날렸다. 37세때 중국 유학생과의 인연으로 4년동안 중국에 체류하면서 중국과학사를 연구해 '중국의 과학과 문명'이라는 연구서를 각 분야별로 나눠 저술해 많은 서양인들의 관심을 중국 연구에 쏠리게 했다.

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Comparison of gait ability according to types of assistive device for ankle joint of chronic hemiplegic stroke survivors (발목관절 보조 도구에 따른 만성 뇌졸중 편마비 장애인의 보행 비교)

  • Park, Dong-Chun;Jung, Jung-Hee;Kim, Won-Deuk;Son, Il-Hyun;Lee, Yang-Jin;Lee, GyuChang
    • Journal of Korean Physical Therapy Science
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    • v.28 no.2
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    • pp.30-39
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    • 2021
  • Background: The purpose of this study was to compare the differences in gait and mobility according to the types of assistive device for ankle joint including ankle foot orthosis (AFO), non-elastic tape, elastic tape, and high ankle shoes in chronic hemiplegic stroke survivors. Design: A cross-over design. Methods: Twelve hemiplegic stroke survivors participated in this study, and they walked under 5 different conditions including bare feet, wearing a AFO, wearing a non-elastic tape, wearing a elastic tape, and wearing a high ankle shoes. During the participants walked, the spatio-temporal gait analysis and mobility examinations were performed. For the spatio-temporal gait analysis (gait velocity and cadence, step length, stride length, and single and double leg support time) and mobility examinations, the gait mat, TUG and TUDS were used. Results: As s results, on the AFO, non-elastic tape, elastic tape, and high ankle shoes, there were significantly differences in the all spatio-temporal gait parameters, TUG, and TUDS compared to barefoot (p<0.05). In particular, all spatio-temporal gait parameters, TUG, TUDS were significantly improved with AFO compared to barefoot. TUG was significantly improved with AFO compared to non-elastic tape, TUG and TUDS were significantly improved with AFO compared to elastic tape, gait velocity was significantly improved with non-elastic tape compared to high ankle shoes, gait velocity and TUG were significantly improved with elastic tape compared to high ankle shoes, and TUDS was significantly improved with non-elastic tape compared to elastic tape. Conclusion: The AFO, non-elastic tape, elastic tape, and high ankle shoes showed a positive effect on gait and mobility compared to barefoot, and among them, wearing AFO was most effective for improving gait and mobility of chronic hemiplegic stroke survivors.