A Study on Water-line Performance Improvement based on OFDM System for Underwater Communication

Seungho Lee,Junghoon Lee,Inkap Park,Sijin Lee,Sunghwa Lee,Youngkwan Choi,Jintae Kim 보안공학연구지원센터 2012 International Journal of Software Engineering and Vol.6 No.4

레이저를 이용한 OLED용 유기 필름 코팅

이시진(Sijin Lee),배상윤(Sangyoon Bae),이광원(Kwangwon Lee),이강인(Kangin Lee),이종훈(Jonghoon Lee) 한국생산제조학회 2011 한국생산제조시스템학회 학술발표대회 논문집 Vol.2011 No.4

레이저를 이용하여 유기물 필름을 유기발광 다이오드(OLED) 기판에 입히는 방법에는 레이저 승화법(laser induced pattern-wise sublimation;LIPS)과 레이저 열전사법(laser induced thermal printing;LITI)이 있다. 이 두 방법에 사용하는 공여 기판에 대하여 공여기판과 수여기판 사이의 두께를 조절하면서 레이저 입사 시간에 따른 유기 필름의 승화와 OLED 기판에 부착된 유기 필름을 광학현미경, 형광현미경, 원자현미경을 이용하여 관측하고 유기물이 이동하는 과정을 분석하였다.

Analysis of Characteristics and Mortality in Cardiac Arrest Patients by Hospital Level: a Nationwide Population-based Study

Lee Sijin,Lee Sung Woo,Han Kap Su,Ki Myung,Ko Young Hwii,Kim Su Jin 대한의학회 2021 Journal of Korean medical science Vol.36 No.25

Background: Survival and post-cardiac arrest care vary considerably by hospital, region, and country. In the current study, we aimed to analyze mortality in patients who underwent cardiac arrest by hospital level, and to reveal differences in patient characteristics and hospital factors, including post-cardiac arrest care, hospital costs, and adherence to changes in resuscitation guidelines. Methods: We enrolled adult patients (≥ 20 years) who suffered non-traumatic cardiac arrest from 2006 to 2015. Patient demographics, insurance type, admission route, comorbidities, treatments, and hospital costs were extracted from the National Health Insurance Service database. We categorized patients into tertiary hospital, general hospital, and hospital groups according to the level of the hospital where they were treated. We analyzed the patients' characteristics, hospital factors, and mortalities among the three groups. We also analyzed post-cardiac arrest care before and after the 2010 guideline changes. The primary end-point was 30 days and 1 year mortality rates. Results: The tertiary hospital, general hospital, and hospital groups represented 32.6%, 49.6%, and 17.8% of 337,042 patients, respectively. The tertiary and general hospital groups were younger, had a lower proportion of medical aid coverage, and fewer comorbidities, compared to the hospital group. Post-cardiac arrest care, such as percutaneous coronary intervention, targeted temperature management, and extracorporeal membrane oxygenation, were provided more frequently in the tertiary and general hospital groups. After adjusting for age, sex, insurance type, urbanization level, admission route, comorbidities, defibrillation, resuscitation medications, angiography, and guideline changes, the tertiary and general hospital groups showed lower 1-year mortality (tertiary hospital vs. general hospital vs. hospital, adjusted odds ratios, 0.538 vs. 0.604 vs. 1; P < 0.001). After 2010 guideline changes, a marked decline in atropine use and an increase in post-cardiac arrest care were observed in the tertiary and general hospital groups. Conclusion: The tertiary and general hospital groups showed lower 30 days and 1 year mortality rates than the hospital group, after adjusting for patient characteristics and hospital factors. Higher-level hospitals provided more post-cardiac arrest care, which led to high hospital costs, and showed good adherence to the guideline change after 2010.

Effects of Acid Rain on Ecosystem in Korea

LEE,SIJIN 경기대학교부설 산업기술종합연구소 1992 산업기술종합연구소 논문집 Vol.8 No.-

In this paper, recent work on effects of acid rain on ecosystem was summerized. Acidic precipitation is the product of many sources, both natural and anthropogenic, with the precursors often transported over long distances crossing national boundaries. Althrough the cause of acid precipitation are currently being debated, the damages which caused by acid precipitation are certainly existed. To reduce the impacts of acid rain on ecosystem. the pattern of energy consumption has to be studied extensively. It is important to examine not only short-term but also long-terns effects of acid rain. An international research institute to work on transport of air pollutants, patterns of energy consumption, and effects of acid precipitation is recommended.

RIDGEWOOD AERATION SYSTEM ANALYSIS : FINE BUBBLE DOME SYSTEM

LEE,SIJIN 경기대학교부설산업기술종합연구소 1990 산업기술종합연구소 논문집 Vol.6 No.-

The Ridgewood Aeration System Analysis was initiated in March. 1983 at the Ridgewood. Wastewater Treatment facility in New Jersey. U.S.A. The purpose of this phase of the project was to evaluate the fine bubble dome aeration system. Both clean and dirty water tests were conduted under batch conditions. A comparison of the transfer efficiencies and a values for coarse and fine bubble systems is made. Significantly higher transfer efficiencies and a values resulted for the fine bubble system under batch conditions. The significant cost savings can be predicted using the fine bubble aeration system compare to the coarse bubble aeration system.

온·오프라인 교수학습을 위한 한국어 익힘책 개발의 실제 -『온라인 세종학당 사이버 한국어 익힘책』 익힘책 개발 사례를 중심으로-

이미향 ( Lee Mihyang ),손시진 ( Son Sijin ),이승연 ( Lee Seungyeon ) 이중언어학회 2022 이중언어학 Vol.87 No.-

The purpose of this study is to examine the principles and directions of the development of workbooks required for Korean language education. To this end, first of all, the current status and needs of workbooks for language education were examined, and the principle of developing workbooks, derived through the process of developing “Sejong Cyber Korean Workbook”, was discussed. Through this, the study would like to emphasise the need for multilateral discussions on the development of workbooks by learner’s situation and level, and the environment of using educational materials. The workbook is a book that allows learners to learn concepts and principles by solving questions, and is currently actively used in math subjects. On the other hand, there is little discussion on workbooks that would contribute to the process of learning a language. This seems to be because the existing foreign language education was led by teachers in the classroom. After the educational digitisation, microlearning and self-learning have been increased. Many learners who want to learn Korean abroad are difficult to learn through educators, so various auxiliary materials to help ease learning are more urgent than those in Korea. In particular, cyber Korean beginner and intermediate level workbooks should be learning materials that meet the demand for online Korean language learning and also help foreign Korean language teachers’ field guidance. The educational materials that consider both online and offline environments become a workbook that considers both self-learning and classroom use. Therefore, this book could be called ‘workbook for activities’. In addition, online workbooks should be equipped with devices to arouse learners’ interest and motivate learners. This study has focused on the importance of the future meaning of the workbook, and attempted to contribute to helping the ease of teaching and learning by deriving the principle of developing the workbook suitable for Korean language learning at King Sejong Institute. Developing and producing a workbook in the ‘cyber Korean learning’ course is a process of completing educational materials prepared at the national level. In addition, by developing the workbooks across beginner and intermediate levels, not only local learners abroad are able to do supplement and in-depth learning activities linked to the lecture contents, but also a guide book is provided to the teachers to guide them, to maximise the effectiveness of Korean and Korean culture education abroad. (Yeungnam University, Sahmyook University)

소아영양집중지원팀 활동이 정맥 영양 지원을 받는 소아 입원 환자에 미치는 영향

백시진 ( Sijin Baek ),노주현 ( Juhyun Rho ),남궁형욱 ( Hyung Wook Namgung ),이은숙 ( Eunsook Lee ),김은경,양혜란 ( Hye Ran Yang ),( Euni Lee ) 한국정맥경장영양학회 2020 한국정맥경장영양학회지 Vol.12 No.1

Purpose: Malnutrition is a common problem in hospitalized patients that can increase the risk of complications, including infections and length of hospitalization. Appropriate nutritional support is important, particularly in pediatric patients, because growth and development are closely related to the nutritional supply. This study examined the status of nutritional support for pediatric patients in general wards to determine if interventions of the pediatric nutrition support team (pNST) contribute to appropriate nutritional support and help improve their nutritional status. Methods: Between July 2016 and June 2017, all pediatric inpatients who received parenteral nutrition support at the Seoul National University Bundang Hospital were recruited and divided into the NST group and non-NST group according to the activities of pNST. The nutritional status was assessed in all subjects, and the calories and proteins delivered through nutritional support in each group were calculated and then compared with the recommended requirements in pediatric patients. Results: The number of patients recruited was 174: 100 (57.5%) in the NST group and 74 (42.5%) in the non-NST group. Significantly more calories and protein were supplied in the NST group than the non-NST group in hospitalized children aged between four and 17 years (P<0.05). In the non-NST group, the amounts of calories supplied were insufficient compared to the recommended requirements. The proportion of patients supplied with the appropriate number of calories was 60.0% in the NST group and 20.0% in the non-NST group (P<0.001), and the proportion of cases supplied with the appropriate amount of protein was 87.0% in the NST group and 62.2% in the non-NST group (P<0.001). Conclusion: Interventions of the pediatric nutrition support team contributed to the sufficient supply of calories and protein and the improvement of clinical outcomes in hospitalized children on parenteral nutrition therapy.

마이크로에멀젼 방법에 의해 제조된 Ag/TiO₂의 Reactive Orange 16 제거에 관한 연구

이시진(SiJin Lee) 한국지반환경공학회 2019 한국지반환경공학회논문집 Vol.20 No.11

본 연구에서는 장파장에서 감응하는 광촉매를 개발하기 위하여 상용화된 TiO₂에 Ag를 도핑하여 제조하였으며 광촉매 효율을 향상시키기 위하여 귀금속의 분산을 증대시키는 마이크로에멀젼 방법을 이용하였다. 제조된 Ag/TiO₂의 물리적 특성은 SEM(Scanning Electron Microscopy), FE-TEM(Field Emission Transmission Electron Microscopy), DRS(Diffuse Reflectance Spectroscopy)를 통해 분석하였다. RO 16(Reactive Orange 16)에 대한 광촉매의 제거 효율은 25ppm의 RO 16을 대상으로 UV-A 영역(365nm)에서 수행하였다. Ag의 도핑방법에 의한 광촉매 효율을 비교하기 위해 볼밀링 및 딥코팅 방법으로 제조하여 광촉매 효율을 분석하였으며 광촉매 효율에 대한 Ag 및 계면활성제 함량에 대한 최적화를 진행하였다. 도핑방법에 따른 RO 16 제거효율 분석 결과, 마이크로에멀젼 방법으로 제조한 Ag/TiO₂의 RO 16 제거효율이 가장 높았으며 Ag 함량 2wt%, 계면활성제 0.5g에서 가장 높은 제거효율을 보였다. For the development of long-wavelength responding photocatalyst, Ag was applied to commercial TiO₂ to produce Ag/TiO₂ photocatalyst. Moreover, micro-emulsion method was used in order to increase the efficiency of the photocatalyst by enhancing the dispersion of Ag. Physical properties of the manufactured catalyst were analyzed by scanning electron microscopy (SEM), field emission transmission electron microscopy (FE-TEM) and diffuse reflectance spectroscopy (DRS). For the catalytic performance measurement, RO 16 (Reactive Orange 16) removal was performed with 25 ppm RO 16 under UV-A (365 nm) irradiation. In addition, ball milling and dip-coating method were used to synthesize the photocatalyst for the comparison of the outcomes of using different synthesis methods. In addition, catalytic performance was improved by varying the Ag content and surfactant content. The highest catalytic performance was shown at Ag/TiO₂ synthesized by micro-emulsion method with 2 wt% of Ag content, and 0.5 g of the surfactant.

전자빔을 이용한 통계적 Diazinon 분해특성 연구

이시진(Sijin Lee) 한국지반환경공학회 2013 한국지반환경공학회논문집 Vol.14 No.5

본 연구에서는 전자빔공정에서 반응표면법의 하나인 Box-Behnken법을 이용하여 주요 인자로서 diazinon 농도(X₁), 조사강도(X₂)와 pH(X₃)를 토대로 3개 수준으로 구성된 실험설계에 따라 diazinon의 제거와 무기화 특성에 대해 연구하였다. 우선 pH와 diazinon 농도의 영향이 반응표면법(RSM)에 적용될 적정 범위를 결정하기 위해 수행되었다. 통계적 접근은 회귀분석과 분산분석(ANOVA)를 각 인자별 정량적 비교를 도출하기 위해 적용하였으며, 인자별 영향은 조사강도>diazinon 농도>pH의 순으로 나타났다. 회귀모델은 최적화도구를 이용하여 운영조건의 영향을 고려한 최적점을 예측하였으며, 그에 따른 모델식은 Y₁=81.73-5.58X₁+23.69X₂-14.23X₂²+4.22X₃²(R²=99.7%), Y²=35.23-3.01X₁+10.79X₂-7.58X₂² (R²=97.9%)로 도출하였다. 그에 따른 결과는 diazinon 농도 12.75mg/L와 조사강도 4.26kGy에서 diazinon 제거율 95.7%, TOC 저감율은 41.8%로 나타났다. pH 조건은 기존의 다른 고도산화공정(AOPs)에 비해 전자빔 공정에서는 유의한 영향이 없는 것으로 나타났다. In this study, the characteristics of degradation and mineralization of diazinon using a statistical approach based on Box-Behnken design (BBD, one of response surface method) was investigated in an E-beam process, and also the main factors with diazinon concentration (X₁), irradiatin intensity (X₂) and pH (X₃) which consisted of 3 levels in each factor was set up to determine the effects of factors and optimization. At first, effects of pH and diazinon concentration were investigated to determine the proper range of application on response surface method(RSM). In statistical approach, the regression analysis and analysis of variance (ANOVA) were applied to evaluate the quantitative comparison of each factors in order to obtain the effects were irradiation intensity >diazinon concentration>pH. The regression model predicted the optimization point using the response optimizer to consider the effects of operation conditions were Y₁=81.73-5.58X₁+23.69X₂-14.23X₂²+4.22X₃²(R²=99.7%), Y²=35.23-3.01X₁+10.79X₂-7.58X₂² (R²=97.9%)and 95.7% of diazinon degradation, 41.8% of TOC reduction at 12.75mg/L and 4.26kGy, respectively. The pH condition was not significantly affects on E-beam process than other advanced oxidation processes (AOPs).

Effect of Laser Beam Trajectory on Donor Plate in Laser Induced Thermal Printing Process

Kwangwon Lee,Sijin Lee,권진혁,이종훈 한국광학회 2011 Current Optics and Photonics Vol.15 No.4

Organic (Alq3) film, which was coated on a donor plate, was transferred to an organic light emitting diode (OLED) substrate with help of heat generated by a dithering laser beam. The laser beam was diffracted in an acousto-optic modulator (AOM), then focused on the laser-to-heat converting layer of the donor plate; the focused spot followed trajectories guided by rotation of a Galvano-mirror. Three different functional waveforms, sine wave, square wave, and saw tooth wave were applied to the AOM as modulation signal to generate the dithering beam. The fluorescence microscope images of the donor plate showed that the patterns of removed Alq3 film were affected considerably by the modulation waveforms and the phase difference between adjacent dithering beams. Further, the printed images of Alq3 film on the OLED substrate were different from the patterns of removed Alq3 film. Atomic force microscope images indicated that not only direct transfer but also deposition by sublimated vapor of Alq3 contributed to the pattern formation. Printed patterns affected considerably the electricity-to-light conversion characteristics of OLEDs. For uniform transfer, not only the phase relation of dithering beam lines but also adequate waveform were important.