운전면허시험 강화에 따른 교통안전 효과 분석 연구

이창민,이철기,이상수,윤일수,Lee, Chang Min,Lee, Choul Ki,Lee, Sang Soo,Yun, Ilsoo 한국ITS학회 2020 한국ITS학회논문지 Vol.19 No.5

2011년 운전면허시험 간소화 제도가 도입된 이후 변별력이 없어 교통안전에 미흡하다는 부정적인 견해가 많았다. 이에 2016년 12월 22일부터 개선된 운전면허시험이 도입되었고 현재까지 운영되고 있다. 따라서 본 연구는 개선된 운전면허시험이 도입된 이후 어떤 효과가 있었으며 무엇이 유효했는지 살펴보고자 교통안전 통계자료 분석, 체감도 조사를 수행하였다. 분석 결과, 현재 시험이 적정한 변별력을 갖췄다고 보여 지며, 과거보다 공정성 체감은 상당 수준 올라온 것으로 인식된다. 실효성 부문에서는 아직까지 운전자의 눈높이를 만족하지 못한 것으로 사료되며, 향후에는 보다 심도 있는 연구와 교통선진국 사례를 검토할 필요가 있다. After the driver test was simplified in 2011, there were criticisms of its inadequate level of safety standards. A new and improved test was adopted in December 2016. This study investigated the impact of the changes to the test on safety, and analyzed traffic safety statistics and sensory evaluations to determine the effect of the improved driving license test. The analysis concluded that the current test has a proper discrimination and that fairness has increased considerably. The analysis also identified measures that, once adopted, will improve the conduct of driver tests. In the future, it will be necessary to conduct more in-depth studies and to review cases of advanced countries.

모과내 기능성 유용성분 용매추출공정의 최적화

전주영 ( Ju Yeong Jeon ),조인희 ( In Hee Jo ),경현규 ( Hyun Kyu Kyung ),김현아 ( Hyun A Kim ),이창민 ( Chang Min Lee ),최용희 ( Yong Hee Choi ) 한국산업식품공학회 2010 산업 식품공학 Vol.14 No.2

본 연구에서는 모과내의 여러 가지 기능성 유용성분을 효과적으로 추출하기 위해서, 모과나무의 익은 열매로 만든 약재인 모과를 사용 하였다. 모과의 기능성 유용성분용매 추출 공정의 최적 조건을 확립하고자 하였다. 모과를 에탄올에 추출하여 반응표면 분석법으로 모니터링하여 최적 용매 조건을 설정하였다. 중심합성계획법에 따라 시료에 대한 용매비(X1)와 추출온도(X2), 추출시간(X3)을 요인변수로 하고 추출수율(Y1), 총페놀 함량(Y2), 전자공여능(Y3), 갈색도(Y4), 환원당(Y5)을 종속변수로 하여 시행하였다. 실험 결과 추출수율은 추출 온도와 추출 시간에 유의하게 영향을 받음을 알 수 있었다. 안장점에서 추출조건은 시료에 대한 용매비는 26.38mL/g, 추출온도는 72.82oC, 추출시간은 74.86 min에서 최대값을 나타내었다. 총페놀 함량은 용매비와 시간에 영향을 거의 받지 않았고 추출시간에는 영향을 받았으며, 최대값은 20.70mg/mL 로 나타났다. 이때의 추출조건은 시료에 대한 용매비는 22.61mL/g, 추출온도는 84.49oC, 추출시간은 77.25 min으로 나타났다. 전자공여능은 추출온도에 따라 유의하게 영향을 받은 것으로 나타났다. 안장점에서의 추출조건인 시료에 대한 용매비 10.65mL/g, 추출온도 67.78oC, 추출시간 96.75 min에서 추출수율은 94.12%로 예측되었다. 갈색도에 대한 추출조건은 시료에 대한 용매비 23.77mL/g, 추출온도 87.27oC, 추출시간 96.68 min 일 때 안장점이 나타났다. 환원당은 시료에 대한 용매비 26.83mL/g, 추출온도 82.167oC, 추출시간 81.94 min에서 10.55mg/mL로 최대값을 나타내었고 추출시간에 영향을 받았다. In this study, various active functional components in Chinese Quince were extracted by solvent extraction method. A central composit design for optimization was applied to investigate the effects of independent variables such as solvent to sample ratio (X1), extraction temperature (X2), and extraction time (X3) on the soluble solid contents (Y1), total phenols (Y2), electron donating ability (Y3), browning color (Y4) and reducing sugar contents (Y5). It was found that extraction temperature and extraction time were the main effective factors in this extraction process. The maximum soluble solid contents of 35.77% was obtained at 26.38mL/g (X1), 72.82oC (X2) and 74.86 min (X3) in saddle point. Total phenols were rarely affected by solvent ratio and extraction time, but it was affected by extraction temperature. The maximum total phenols of 20.70% was obtained at 22.61mL/g (X1), 84.49oC (X2), 77.25 min (X3) in saddle point. The electron donating ability was affected by extraction time. The maximum electron donating ability of 94.12% was obtained at 10.65mL/g (X1), 67.78oC (X2), 96.75 min (X3) in saddle point. The maximum browning color of 0.32% was obtained at 23.77mL/g (X1), 87.27oC (X2), 96.68 min (X3) in saddle point. The maximum value of reducing sugar content of 10.55% was obtained at 26.83mL/g (X1), 82.167oC (X2), 81.94 min (X3). Reducing sugar content was affected by extraction time.

다탄성 Insole의 Workload 감소 효과에 관한 연구

이창민,이경득,오연주,김진훈,Lee, Chang-Min,Lee, Kyun-Deuk,Oh, Yeon-Ju,Kim, Jin-Hoon 대한인간공학회 2007 大韓人間工學會誌 Vol.26 No.2

The Work-Related Musculoskeletal Disorders (WMSDs) can be occurred by various factors such as repetition, forceful exertions and awkward postures. Especially, occurrences of the WMSDs on the waist and lower limb are reported in workplaces, demanded standing postures for a long time, in service and manufacturing industry. The static and standing postures without movement for a long time increase work loads to the lower limb and the waist. Accordingly, anti-fatigue mat or anti-fatigue insole is used as a preventing device of the WMSDs. However anti-fatigue mats are limited in space and movement. In this study, multi-elastic insoles are designed and shown the effects of the workload reduction for a long time under the standing work. The foot pressures and EMG (Electromyography) are measured at 0 hour and after 2 hours by 6 health students in their twenties. The 6 prototype insoles are designed with three elastic (Low, Medium and High). These insoles are compared with no insole (insole type 7) as control group. The EMG measurement was conducted to waist (erector spinae muscle), thigh (vastus lateralis muscle) and calf (gastrocnemius muscle). The foot pressure is analyzed by mean pressure value and the EMG analysis is investigated through MF (Median Frequency), MPF (Mean Power Frequency) and ZCR (Zero Crossing Rate). The results of the foot pressure show that the multi-elastic insoles had smaller foot pressure value than that of no-insole. Moreover, Insole 2 and Insole 3 have the smallest increasing rate in foot pressure. The EMG results show that the multi-elastic insoles had smaller EMG shift value than that of no-insole in 2 hour, and then shift value shows the smallest value in Insole 2. Therefore, this study presents that the multi-elastic insoles have reducing effects of the work load for a long time standing work in both side of foot pressure and EMG.

IgA신장병 환자에서 발생한 호산구다발근염 1예

이창민,Lee, Chang-Min 대한임상신경생리학회 2015 Annals of Clinical Neurophysiology Vol.17 No.2

H₂S제거를 위한 아연계 탈황제 제조 및 반응특성 연구

이창민,윤여일,김성현,Lee, Chang Min,Yoon, Yea Il,Kim, Sung Hyun 한국공업화학회 1999 공업화학 Vol.10 No.2

Zinc-based sorbents for $H_2S$ removal were prepared. The reactivity of sorbents was investigated by the successive cycles of sulfidation-regeneration at $650^{\circ}C$ in a fixed bed reactor. The desulfurization sorbents were prepared with granulation method to produce a spherical pellet with good attrition resistance. The fresh and reacted sorbents were characterized by X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS) and the characteristics of sorbents on calcination conditons were analysed by Mercury Porosimetery and BET. The reactivity of sorbents decreased as the number of sulfidation-regeneration cycle increased. It is due to the zinc loss and the increase of the diffusion resistance by sintering, cracking and spalling of sorbents at the high temperature. $H_2S$를 제거를 위한 아연계 복합금속산화물 탈황제를 제조하고 반응특성을 연구하였다. 최적 황화반응 온도인 $650^{\circ}C$의 고정층에서 탈황-재생의 연속 cycle에 따른 반응성을 관찰하였다. 내마모성 향상을 위한 구형입자의 탈황제를 제조하기 위해 Granulation방법을 이용하였다. XRD와 XPS분석에 의해 zinc titanate결정생성을 확인하였고 소성조건에 따른 탈황제의 특성을 분석하기 위해 mercury porosimetry와 BET분석을 행하였다. Cycle이 증가함에 따라 고온에서의 zinc loss와 sintering, cracking, 그리고 spalling에 의한 탈황제의 확산저항의 증가로 인해 반응성은 떨어졌다.

집배원 근골격계 질환 예방을 위한 수구분대 개선에 관한 연구

이창민,오연주,Lee, Chang-Min,O, Yeon-Ju 대한인간공학회 2004 大韓人間工學會誌 Vol.23 No.4

The purpose of this study is to redesign a letter sorting station and to present the optimal work-space through the ergonomic analysis of the sorting station for reducing the 'Work-Related MusculoSkeletal Disorders(WMSDs)'. We surveyed the work environment in terms of the reason causing WMSDs. According to the survey results, Deltoid on the arm, Trapezius on the shoulder and Erector Spinae on the waist are most frequent attacking parts. Accordingly, We classified sorting stations by the horizontal work-space(Level 1, Level 2, Level 3) and the vertical work space(Level 1, Level 2) based on the criteria of ergonomic optimal work-space. In addition we improved the sorting station through investigation and analysis of the work-load regard the each defined work-space. In order to analyze the effect of the horizontal and vertical work-space, subjects carried out simulated sorting tasks. Each level(Level 1, Level 2, Level3) of the horizontal work-space is significant regarding each muscles(the shoulder, arm and waist), and each level(Level 1, Level 2) of the vertical work-space is significant regarding the arm and waist, but not shoulder. Finally, we founded the difference of work-load according to the work-spaces. Then, it is necessary to improve the work-space causing the high work-load(Level 3 of the horizontal work-space). Then, this study presented the specification of a sorting station which is suitable to the korean body size, and constructed the 3D shaped model of the stations by the ergonomic analysis.

양자점 디스플레이 기술의 현재와 미래

이창민,이우석,채희엽,Lee, Chang-Min,Lee, U-Seok,Chae, Hui-Yeop 한국진공학회 2017 진공 이야기 Vol.4 No.2

구두 굽의 형태가 인체의 근골격계에 미치는 영향에 관한 연구

이창민,정은희,Lee, Chang-Min,Jeong, Eun-Hui 대한인간공학회 2004 大韓人間工學會誌 Vol.23 No.1

In terms of women engaged in clerical job. working time of the workers who mainly keep standing with their high-heeled shoes on has been increasing. According]y. they are exposed to many kinds of foot deformation caused by loads of lower back and lower extremities due to high-heeled shoes. The type of heels they usually wear are diverse though the hight is same. In this study. we investigated most women's favorite styles of shoes concerned with heights. types and contact areas of the heels. Hence. we designed three kinds of shoes for an experiment: their contact areas with ground are 1 cm2. 2-4 cm2 and over 9 cm2 according to the heel heights. respectively. To investigate the biomechanical effects. analysis of motion and EMG were applied to the experiments. In addition. foot pressure distribution was measured for more detailed analysis. Six healthy young women were participated in this experiments. The result showed the heel becoming higher and narrower increased not only fluctuation of CBM(Center of Body Mass). but also the load of low back muscle and lower extremities. Accordingly. there was significant difference among types of the heel in terms of the role supporting load of the body. though the height is same. Especially. the difference among the pressures on a foot was most significant. In conclusion. we verified biomechanical effects are related with the contact area of a heel with ground as well as the hight.

망막질환이 동반된 난치성 녹내장에서의 유리체절제술과 평면부를 통한 아메드장치삽입술

이창민,김은아,조영욱,Chang Min Lee,Eun Ah Kim,Young Wook Cho 대한안과학회 2011 대한안과학회지 Vol.52 No.1

Purpose: To evaluate the efficacy and long-term prognosis of pars plana vitrectomy and Ahmed valve implantation for intractable glaucoma comorbid with retinal disorders. Methods: A retrospective review of 34 eyes of 30 patients receiving pars plana vitrectomy and Ahmed valve implantation for intractable glaucoma comorbid with retinal disorders was performed. Preoperative and postoperative intraocular pressure (IOP) and visual acuity, the usage of IOP-lowering medications and postoperative complications, and surgical success rate were evaluated. Results: IOP and the number of IOP-lowering medications showed a significant decrease after pars plana vitrectomy and Ahmed valve implantation, as compared to before surgery (p < 0.001). The success rate was 88%, 88%, 84% and 85% postoperatively at 1 month, 6 months, 1 year and 3 years respectively. The mean follow up period was 24.21 ± 14.99 months. Complications related to surgery included hyphema in 2 eyes, recurrent corneal epithelial erosion and defect in 2 eyes, corneal ulcer in 2 eyes and vitreous hemorrhage in 4 eyes. Visual acuity improved in 14 eyes (41.1%), no changes in 13 eyes (38.2%) and decreased in 7 eyes (20.6%). Conclusions: Pars plana vitrectomy and Ahmed valve implantation for intractable glaucoma comorbid with retinal disorders show long-term efficacy in lowering IOP. J Korean Ophthalmol Soc 2011;52(1):46-52

PSS 상 버퍼층 종류에 따른 GaN 박막 성장 특성 비교

이창민,강병훈,김대식,변동진,Lee, Chang-Min,Kang, Byung Hoon,Kim, Dae-Sik,Byun, Dongjin 한국재료학회 2014 한국재료학회지 Vol.24 No.12

GaN is most commonly used to make LED elements. But, due to differences of the thermal expansion coefficient and lattice mismatch with sapphire, dislocations have occurred at about $109{\sim}1010/cm^2$. Generally, a low temperature GaN buffer layer is used between the GaN layer and the sapphire substrate in order to reduce the dislocation density and improve the characteristics of the thin film, and thus to increase the efficiency of the LED. Further, patterned sapphire substrate (PSS) are applied to improve the light extraction efficiency. In this experiment, using an AlN buffer layer on PSS in place of the GaN buffer layer that is used mainly to improve the properties of the GaN film, light extraction efficiency and overall properties of the thin film are improved at the same time. The AlN buffer layer was deposited by using a sputter and the AlN buffer layer thickness was determined to be 25 nm through XRD analysis after growing the GaN film at $1070^{\circ}C$ on the AlN buffer CPSS (C-plane Patterned Sapphire Substrate, AlN buffer 25 nm, 100 nm, 200 nm, 300 nm). The GaN film layer formed by applying a 2 step epitaxial lateral overgrowth (ELOG) process, and by changing temperatures ($1020{\sim}1070^{\circ}C$) and pressures (85~300 Torr). To confirm the surface morphology, we used SEM, AFM, and optical microscopy. To analyze the properties (dislocation density and crystallinity) of a thin film, we used HR-XRD and Cathodoluminescence.