• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권6호
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• pp.385-392
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• 2020

Objectives: This study evaluates soft tissue changes of the upper lip and nose after maxillary setback with orthognathic surgery such as Le Fort I or anterior segmental osteotomy. Materials and Methods: All 50 patients with bimaxillary protrusion and skeletal Class II malocclusion underwent Le Fort I or anterior segmental osteotomy with backward movement. Soft and hard tissue changes were analyzed using cephalograms collected preoperatively and 6 months postoperatively. Results: Cluster analysis on the ratios shows that 2 lines intersected at 4 mm point. Based on this point, we divided the subjects into 2 groups: Group A (less than 4 mm, 27 subjects) and Group B (more than 4 mm, 23 subjects). Also, each group was divided according to changes of upper incisor angle (≥4°=A1, B1 or <4°=A2, B2). The correlation between A and B groups for A'/ANS and Ls/Is (P<0.001) was significant; A'/A (P=0.002), PRN/A (P=0.043), PRN/ANS (P=0.032), and St/Is (P=0.010). Variation of nasolabial angle between the two groups was not significant. There was no significant correlation of vertical movement and angle variation. Conclusion: The ratio of soft tissue to hard tissue movement depends on the amount of posterior movement in the maxilla, showing approximately two times higher rates in most of the midface when posterior movement was greater than 4 mm. The soft tissue changes caused by posterior movement of the maxilla were little affected by angular changes of upper incisors. Interestingly, nasolabial angle showed a different tendency between A and B groups and was more affected by incisal angular changes when horizontal posterior movement was less than 4 mm.

• The Journal of Advanced Prosthodontics
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• 제14권5호
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• pp.324-333
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• 2022

PURPOSE. The purpose of this study is to evaluate translucency and masking ability of translucent zirconia compared to conventional zirconia and lithium disilicate materials. MATERIALS AND METHODS. Three types of zirconia blocks with different yttria contents (3Y, 4Y, 5.5Y) and LS blocks (Rosetta SM) were used. Ten specimens for each group were fabricated with 10 mm diameter, with both 0.8 mm and 1.5 mm thicknesses (± 0.02 mm). All groups of zirconia specimens were sintered and polished according to the manufacturer's instructions. To calculate the translucency parameter (TP), CIELAB value was measured with a spectrophotometer on black and white backgrounds. To investigate the color masking abilities, background shades of A2, normal dentin, discolored dentin, and titanium were used. The color difference (ΔE) was calculated with the CIELAB values of A2 shade background as a reference compared with the values in the various backgrounds. One-way ANOVA and Bonferroni tests were conducted (P < .05). RESULTS. The TP values of zirconia specimens increased as the yttria content increased. All materials used in the study were able to adequately mask normal dentin shade (ΔE < 5.5), but were incapable of masking severely discolored dentin (ΔE > 5.5). On the titanium background, all materials of 1.5 mm thickness were able to mask the background shade, but with a thickness of 0.8 mm, only 3Y-TZP and 4Y-PSZ were able to mask titanium background. CONCLUSION. All zirconia materials and lithium disilicate specimens used in this study were unable to adequately mask the shade of severely discolored dentin. It is recommended to use 3Y-TZP or 4Y-PSZ with a sufficient thickness of 0.8 mm or more to mask titanium.

• Journal of Sport and Applied Science
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• 제7권1호
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• pp.21-29
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• 2023

Purpose: This study was to investigate the effects of isometric exercise on muscle activity and body balance ability in asymmetrical walkers. Research design, data, and methodology: Twenty gait asymmetry people were divided to unilateral exercise group (UG, n=10) and bilateral exercise group (BG, n=10). UG were performed unilateral exercise for 60 minutes, three times a week, and 16 weeks, and BG were performed one side and then the other side alternately for 60 minutes, three times a week, and 16 weeks. Muscle activity and body balance ability were measured before, after 4 and 16 weeks isometric exercise. Moreover, SI (symmetry index; SI) was calculated from the measured value of SL (step length). Statistical analyses were conducted using one-way ANOVA and two-way ANOVA with repeated measures, a paired t-test, and multiple comparisons according to Scheffe. Results: In the muscle activity, ST decreased significantly in short step length(S-SL) and BG of LS compared to before isometric exercise(p<.05), and GCM decreased significantly in BG of S-SL(p<.05). As for body balance ability, the mSEBT-A difference between L-SL and S-SL was decreased significantly in UG(p<.05). And the respective total scores of L-SL and S-SL, mSEBT-PM and mSEBT-PL were increased significantly in BG(p<.05). Conclusions: As a result, in this study above, it was confirmed that isometric exercise improved muscle activity and body balance ability in asymmetrical walkers.

• 자동차안전학회지
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• 제6권1호
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• pp.5-9
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• 2014

Over the past ten years, since the introduction of the side crash test regulation in Europe, much research work has been performed internationally to develop new and modified test procedures to improve the level of occupant protection offered by vehicles in side crash test. This research has been co-ordinated and finally contributed to development of an AE-MDB(Advanced European Moving Deformable Barrier) and WorldSID (Worldwide Side Impact Dummy). EuroNCAP(European New Car Assessment Program) has the plan to conduct AE-MDB side crash test using WorldSID from 2015 by replacing Progressive MDB and EuroSID II. Automobile manufacturers need to respond to these changes closely. This paper is to find dominant control factor and analyze it of WorldSID 50%ile dummy injury through AE-MDB side crash test by predicting best and worst condition. And control factors will be validated within EuroNCAP regulations. This paper is analyzed by DFSS(Design for six sigma) which contains 5 control factors and is evaluated by ANOVA with the data as a result of LS-DYNA analysis correlated with crash pulse from 50 kph AE-MDB side crash test using WorldSID 50%ile dummy.

• 소성∙가공
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• 제32권1호
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• pp.12-19
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• 2023

The armature core is a part responsible for the skeleton of the steering wheel. Currently, in the case of commercial trucks, the main parts of the parts are manufactured separately and then the product is produced through welding. In the case of this production method, quality and cost problems of the welded parts occur, and an integrated armature core made of magnesium alloy is used in passenger vehicles. However, in the case of commercial trucks, there is no application case and research is insufficient. Therefore, this study aims to develop an all-in-one armature core that simultaneously applies a magnesium alloy material and a die casting method to reduce the weight and improve the quality of the existing steel armature core. The product was modeled based on the shape of a commercial product, and finite element analysis (FEA) was performed through Ls-dyna, a general-purpose analysis program. Through digital image correlation (DIC) and uniaxial tensile test, the accurate physical properties of the material were obtained and applied to the analysis. A total of four types of compression were applied by changing the angle and ground contact area of the product according to the actual reliability test conditions. analysis was carried out. As a result of FEA, it was confirmed that damage occurred in the spoke area, and spoke thickness (t_spoke), base thickness (t_base), and rim and spoke connection (R) were designated as design variables, and the total weight and maximum equivalent stress occurring in the armature core We specify an objective function that simultaneously minimizes . A prediction function was derived using the sequential response surface method to identify design variables that minimized the objective function, and it was confirmed that it was improved by 22%.

• 한국식품영양학회지
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• 제36권6호
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• pp.462-470
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• 2023

The aim of this study was to investigate the hypoglycemic effects of saengshik in Sprague-Dawley (SD) rats and to explore the potential of three commercially available saengshik products (BS, LS, WS) as an alternative diabetic meal. Blood glucose levels were measured at 30, 60, 90, 120, and 150 minutes after the ingestion of experimental materials. In experiment 1, the amount of experimental materials remained the same. We measured blood glucose-related biomarkers as the area under the blood glucose response curve (AUC), glycemic index (GI), maximum concentration (Cmax), and time to reach maximum concentration (Tmax). AUC and Cmax of the experimental group showed significant differences compared to the control group, while GI and Tmax did not show significant differences among the groups but were lower in the experimental group compared to the control group. In experiment 2, carbohydrates were adjusted to the same amount. We measured blood glucose-related biomarkers in the same manner as Experiment 1 and obtained similar results. These hypoglycemic effects appear to be attributed to phytochemicals and dietary fiber found in whole, unrefined grains. These results suggest that saengshik exerts hypoglycemic effects by modulation of glucose-related biomarkers.

• 한국방사선학회논문지
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• 제17권6호
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• pp.851-857
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• 2023

본 연구는 손 방사선검사에서 조사야 크기와 sub ROI의 변화가 EI값에 미치는 영향을 알아보고, 한국인의 평균 손 크기에 적합한 조사야 크기 및 EI값 제시하고, sub ROI 변화가 EI 값에 미치는 영향을 제시하는데 목적이 있다. hand wrist phantom을 대상으로 했으며, 조사조건은 55 kVp, 125 mA, 6.25 mAs로 설정하였고, 초점-영상수용체 간 거리는 110 cm로 적용하였다. 제조사에서 권고하는 sub ROI('ss' 타입)을 기준으로 조사야 크기 4종류(18.7"×18.7", 8"×10", 8"×7.4", 6"×7.4")와 교과서에서 권고하는 조사야 크기 8"×10"에서 sub ROI 5가지를 변화 시키며, 각각 30개의 영상을 획득하였고, 이때 장비에서 나타나는 EI를 비교분석하였다. 조사야 크기 변화에 따른 EI값은 18.7"×18.7"의 경우 1663.7±4.52, 8"×10"은 1489.1±4.49, 8"×7.4"은 1716.9±3.00, 6"×7.4"은 1681.7±3.66로 나타났으며, 각 값의 평균값은 통계적으로 유의했다. sub ROI 변화에 따른 EI값의 평균은 SS의 경우 1489.1±4.49이었으며, LS는 1694.8±5.19, AEC는 2052.9±5.96, VR은 1548.3±3.20, HR은 1663.2±4.33로 나타났다. 한국인의 손 크기를 고려한 적절한 조사야 크기는 8"×7.4"로 나타났다. 또한 손 방사선검사 시 일반적으로 알려진 조사야 크기(8"×10")를 기준으로 조사야 크기가 증가하면 EI값은 최대 15%에서 최소 11%까지 변화되었으며, sub ROI 'SS'를 기준으로 sub ROI 형태 변화에 따른 EI값은 최대 37%에서 최소 3%까지 증가하였다.

• 한국미생물·생명공학회지
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• 제28권3호
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• pp.172-179
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• 2000

여러 재질의 담체를 이용하여 H1-39변이주를 고정화시켜 3.4% 목질계 당화액을 탄소원으로 $37^{\circ}C$, $40^{\circ}C$, $43^{\circ}C$에서 에탄올 발효를 하였는데 전반적으로 유리세포 배양시보다 에탄올 수율, 생산성, 세포수율, 세포 생존율이 향상되었다 온도 37$^{\circ}C$에서는 Ca-alginate와 ABG bead에 고정화된 H1-39변이주에서 각각 가장 높은 14.8 g/1의 에탄올을 생산하였으며 특히 H1-39변이주를 ABG bead에 고정화하여 배양하였을 때 생산성이 1.23g/1-h로 가장높았다. $40^{\circ}C$에서는 ABG bead에 고정화된 H1-39 변이주에서 가장높은 15.2g/1의 에탄올을 생산하였으며 생산성도 0.84g/1-h 로 유리세포 배양시보다 약 91% 증가하였다. 한편 $43^{\circ}C$에서는 ABP고정화 배양을 통해 가장 높은 13.8g/1의 에탄올 생산과 0.77g/1-h의 생산성을 나타내어 유리세포 배양시 보다 각각 14%와 93%의 증가를 보였다.

• 대한치과교정학회지
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• 제37권2호
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• pp.125-136
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• 2007

교정치료에 따른 연조직 변화 양상은 개개인의 차이가 심하므로 교정치료 중 흔히 재평가가 필요하다. 이를 위해서 고정식 교정장치가 부착되어 있는 상태의 입술의 위치와 교정치료 종료 후의 위치에 대한 비교 예측이 필요하다. 이 연구는 교정치료가 종료되어 고정식 교정장치를 제거하는 52명을 대상으로 T1(장치제거 전), T2(장치제거 직후), T3(장치제거 1.5개월 후)의 측모두부방사선사진상에서 입술과 그 주위 연조직을 분석한 결과 다음과 같은 결론을 얻었다. 장치제거 직후(T2-T1) 하순이 후퇴하며 장치제거 직후부터 1.5개월 후 (T3-T2)까지도 계속 후퇴하였다. 장치제거 1.5개월 후 (T3-T1), 기준선(G-perpendicular line)에 대한 입술의 평균 후퇴양은 상순(Ls)에서 0.38mm, 하순(Li)은 0.88 mm를 보였다. 주로 장치제거 직후(T2-T1)에 하순이 후퇴하는 여자군과 달리 남자군은 장치제거 직후부터 1.5개월 후(T3-T2)가지 하순이 주로 후퇴하는 양상을 보였으나, 장치제거 1.5개월 후 (T3-T1)에는 남자군과 여자군간의 뚜렷한 차이를 보이지 않았다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.102-106
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• 2008

본 연구는 SWAT(Soil and Water Assessment Tool) 모형에서 공간입력자료의 다양한 해상도에 의한 수문-수질 모의결과를 비교분석 하고자 하였다. 경안천유역 상류의 농촌 소유역($1.21\;km^2$)을 대상으로 Case A(2m DEM, QucikBird 토지이용도, 1/25,000 토양도), Case B(10m DEM, 1/25,000 토지이용도, 1/25,000 토양도), Case C(30m DEM, Landsat 토지이용도, 1/25,000 토양도)에 해당하는 해상도별 공간입력자료를 구축하였다. 모형의 적용성 평가를 위해 먼저, 경안수위관측소 상류유역($255.44km^2$)을 대상으로 $1999{\sim}2002$년까지 4개년의 자료를 이용하여 유출량 및 Sediment, T-N, T-P에 대한 모형의 검보정을 실시하였다. 유출량에 대한 Nash-Sutcliffe 모형효율은 평균 0.59의 결과를 얻었으며, Sediment, T-N, T-P는 각각 2.08 tons/yr, 4.30 tons/yr, 0.70 tons/yr의 RMSE 오차로 검보정되었다. 모형의 검보정 후, 농촌 소유역을 대상으로 다양한 공간자료(Case A, B, C)를 적용하여 수문, 수질모의를 실시한 결과, 유출량은 토지이용도 해상도에 의한 모의결과의 불확실성이 가장 큰 것으로 분석되었다. QuickBird 토지이용의 유역평균 CN값이 1/25,000과 Landsat 토지이용에 비해 0.4, 1.8 더 크게 분석됨으로서 총유출량도 증가하였다. 유사량과 영영물질 오염부하량에 대한 수질모의 결과는 USLE 인자의 평균 LS 및 K, CFRG 값의 순서로 해상도별 모의결과의 불확실성이 가장 컸으며 토지이용도에 의한 평균 C값에는 큰 변화가 없는 것으로 분석되었다. Case A의 유사량은 B와 C에 비해 23.7%, 50.6% 증가하는 것으로 나타났으며, 유사량 증가에 따른 T-N, T-P 부하량 역시 Case A, B, C 순으로 높게 평가되었다.