Clinical study of alopecia areata in children over a ten-year period (2007-2017)

( Jaewon Kang ),( Sungmin Kim ),( Byungin Ro ) 대한피부과학회 2020 대한피부과학회 학술발표대회집 Vol.72 No.1

Background: Alopecia areata (AA) is a non-scarring, autoimmune, inflammatory hair loss on the scalp and/or the body. The disease affects both adults and children but there are limited data on AA in children compared to AA in adults. Objectives: The purpose of this retrospective study is to evaluate the clinical characteristics, correlation with underlying diseases, and the psychiatric dynamics of pediatric AA from 2007 to 2017. Methods: A retrospective study was performed on 211 out-patients under 14 years old who were diagnosed with alopecia areata in the alopecia clinic of dermatology department from March, 2007 to February, 2017. Results: The proportion of pediatric group in total alopecia areata was 18.0%. Clinically, the alopecia areata were 195 patients(92.4%) followed by those with alopecia totalis(4.7%) and alopecia universalis(2.8%). The ratio of male(44.5%) to female(55.5%) was 1:1.25. Family history of alopecia areata was observed in 9.5% of the patients. The patients that were most susceptible to the disease were only child, eldest child, those who were overloaded with school works, and those with deficient parent-child relationship including familial discord. The most commonly associated disease was atopic dermatitis Conclusion: We have analyzed several clinical features of the pediatric AA, including epidemiology, clinical characteristics, associated disease. This study provides useful data for future research regarding AA in children.

Erythropoietin priming improves the vasculogenic potential of G-CSF mobilized human peripheral blood mononuclear cells

Kang, Jeehoon,Yun, Ji-Yeon,Hur, Jin,Kang, Jin-A,Choi, Jae-Il,Ko, Seung Bum,Lee, Jaewon,Kim, Ju-Young,Hwang, In-Chang,Park, Young-Bae,Kim, Hyo-Soo Oxford University Press 2014 Cardiovascular research Vol.104 No.1

<P><B>Aims</B></P><P>From our previous clinical trials, intracoronary infusion of granulocyte-colony stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cells (<SUP>mob</SUP>PBMCs) proved to be effective in improving myocardial contractility and reducing infarct volume in acute myocardial infarction. We tested the effect of priming <SUP>mob</SUP>PBMCs with erythropoietin (EPO) to augment its therapeutic efficacy.</P><P><B>Methods and results</B></P><P><SUP>mob</SUP>PBMCs were obtained from healthy volunteers after a 3-day subcutaneous injection of G-CSF (10 μg/kg). About 40% of <SUP>mob</SUP>PBMCs were EPO receptor (EPOR) (+) and responded to 6 h EPO-priming (10 IU/mL) by increasing the expression of vasculogenic factors (i.e. IL8, IL10, bFGF, PDGF, MMP9) and adhesion molecules (i.e. integrin αV, β1, β2, β8) through the JAK2 and Akt pathway. These responses were also observed in PBMCs from elderly patients with coronary disease. The conditioned media from EPO-primed <SUP>mob</SUP>PBMCs contained various cytokines such as IL8, IL10, TNFα, and PDGF, which enhanced the migration and tube formation capability of endothelial cells. EPO-primed <SUP>mob</SUP>PBMCs also showed increased adhesion on endothelial cells or fibronectin. Augmented vasculogenic potential of EPO-primed <SUP>mob</SUP>PBMCs was confirmed in a Matrigel plug assay, ischaemic hindlimb, and myocardial infarction models of athymic nude mice. There were two action mechanisms: (i) cellular effects confirmed by direct incorporation of human <SUP>mob</SUP>PBSCs into mouse vasculature and (ii) indirect humoral effects confirmed by the therapeutic effect of the supernatant of EPO-primed <SUP>mob</SUP>PBMCs.</P><P><B>Conclusion</B></P><P>Brief <I>ex vivo</I> EPO-priming is a novel method to augment the vasculogenic potential of human <SUP>mob</SUP>PBMCs, which would help to achieve better results after intracoronary infusion in myocardial infarction patients.</P>

Nanoparticulate Iron Oxide Tubes from Microporous Organic Nanotubes as Stable Anode Materials for Lithium Ion Batteries

Kang, Narae,Park, Ji Hoon,Choi, Jaewon,Jin, Jaewon,Chun, Jiseul,Jung, Il Gu,Jeong, Jaehong,Park, Je‐,Geun,Lee, Sang Moon,Kim, Hae Jin,Son, Seung Uk WILEY‐VCH Verlag 2012 Angewandte Chemie Vol.124 No.27

<P><B>Röhren aus Röhren</B>: Mikroporöse organische Nanoröhren wurden durch Sonogashira‐Kupplung zwischen Tetra(4‐ethinylphenyl)methan und <I>N</I>,<I>N</I>′‐Di(4‐iodphenyl)‐4,4′‐bipyridiniumdichlorid erhalten. Diese Nanoröhren dienten als Template für sekundäre anorganische Materialien, nämlich Fe<SUB>2</SUB>O<SUB>3</SUB>‐Nanoröhren mit hoher Entladekapazität und ausgezeichneter Stabilität.</P>

Efficient Correlation Method for Satellite Thermal Analysis Model Using Multiple Linear Regression and Optimization Algorithms

Jaewon Kang,김건웅,Somin Shin,김정호 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.5

As the thermal analysis model of satellites is used as an important indicator for thermal design, it must accurately simulate the thermal behaviour of actual satellites for precise thermal design. To increase the accuracy of the thermal analysis model, it must be correlated using the thermal balance test data for actual satellite models. To achieve this, we herein propose an efficient correlation method for satellite thermal analysis models using multiple linear regression techniques with quadratic terms and optimization algorithms. The proposed method reduces the amount of computation by choosing dominant parameters through sensitivity analysis and creating a multiple linear regression model that can replace the thermal analysis model in the subsequent optimization process. Subsequently, optimization algorithms are applied to the multiple linear regression model to perform the correlation of the thermal analysis model. In this study, the numerical validation of the proposed method was performed using numerical data from a reference thermal analysis model to verify the reliability and accuracy of the proposed method before it was applied to the correlation of the thermal analysis model using experimental data. The thermal analysis result of the reference thermal analysis model was set as the target value to correlate, and quantitative performance evaluation was performed for various combinations of optimization algorithms and design of experiments methods by comparing the estimated analysis parameters. The results of this study demonstrate that the proposed method can efficiently produce an accurate correlation model for thermal analysis.

A New Accelerated Endurance Test for Terabit NAND Flash Memory Using Interference Effect

Jaewon Cha,Wooheon Kang,Junsub Chung,Kunwoo Park,Sungho Kang Institute of Electrical and Electronics Engineers 2015 IEEE transactions on semiconductor manufacturing Vol.28 No.3

<P>Limited endurance of E/W cycles is a unique restriction of flash memories and the endurance characteristics usually take a longer time to test. In this paper, we proposed a novel endurance test scheme that takes advantage of the parasitic cell-to-cell interference as well as a shortened program time to accelerate the endurance test for terabit NAND flash memory. The novelty of the new scheme is the use of a new test sequence known as even/odd row address sequence (EORAS). The interference effect during the program operation mainly affects the threshold voltage widening in the victim cell and leads to errors linearly during the read operation. We mainly focus on the correlation between the interference and device error rate during the endurance test. Based on the correlation, we use the interference effect as an acceleration factor in EORAS. EORAS is composed of a new program operation for unit test-time reduction. Our experimental results show that the proposed scheme method can induce the raw bit error rate by 50% and thereby improve the cycling time by 19.4% in a 3×-nm flash device. The proposed scheme method can also induce the raw bit error rate by 80% and thereby improve the endurance test time by 30.8% in a 2×-nm flash device. Consequently, the new endurance scheme reduces the test time by 68.4%.</P>

Girth분포를 이용한 LDPC부호의 Puncturing 기법

강재원(Jaewon Kang),박효열(Hyoyol Park),황금찬(Keumchan Whang) 한국통신학회 2004 한국통신학회 학술대회논문집 Vol.2004 No.7

부정류 흐름 모형을 이용한 농경지 배수개선계획 분석

강재원(Jaewon Kang) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.11

배수개선사업은 안전영농을 도모하는 것이지만 사업 시행 후에도 원활한 배수가 이루어지지 않아 농경지의 부분적인 침수가 발생하는 등의 문제가 있다. 본 연구에서는 부정류 해석 모형(SWMM)을 적용하고 소유역의 상황을 반영해서 배수개선사업의 설계에 대해 분석하고 대상지구 침수 피해를 경감시킬 수 있는 유수지 및 배수장 펌프 용량에 따른 영향을 검토하였다. 유역 집중형 네트워크 분석은 소유역의 유출이 본류로 직접 유입되고 배수장 유수지에 유역 전체의 내용적을 부여하였다. 소유역 분산형 네트워크 분석은 본류의 흐름상황에 소유역이 영향을 받으며 각 소유역별로 내용적을 부여하였다. 기존 분석이나 유역 집중형 네트워크 분석의 경우와는 달리 소유역 분산형 네트워크 분석의 경우에는 70 cm 이상의 침수가 배수개선 사업 후에도 발생할 가능성이 있는 것으로 분석되었다. 유수지의 면적 변화는 70 cm 이상의 침수상황 해소에 영향을 미치지 못하였으나 펌프 용량을 60.7% 상향시킨 경우 이를 해소시킬 수 있었다. 따라서 배수개선 설계 및 분석을 위해서는 소유역 분산형 네트워크를 구성하고 흐름지체 등을 고려할 수 있는 부정류 해석을 도입하는 것이 바람직 할 것으로 판단된다. Although the purpose of a drainage improvement project is to promote safe farming, partial flooding in paddy occurs due to insufficient drainage even with this project implemented. In this study, an unsteady flow analysis model was used and the design of the drainage improvement project was analyzed by considering the situation of sub-catchments. In addition, the effect of the capacity of the drainage reservoir and the capacity of drainage pumps to reduce the flooding damage in the study area was reviewed. In the catchment-intensive network analysis, the outflow of the sub-catchment flows directly into the mainstream, and the entire catchment volume is assigned to the drainage reservoir. On the other hand, in the sub-catchment distributed network analysis, each sub-catchment is affected by the flow status of the mainstream, and sub-catchment volume is assigned to each sub-catchment. Moreover, in the case of the sub-catchment distributed network analysis, unlike the existing analysis or the catchment-intensive network analysis, it was found that there is a possibility of inundation of 70 cm or more even after the application of the drainage improvement project. A change in the area of the drainage reservoir did not affect the flooded situation of 70 cm or more, but this situation could be resolved with a pump capacity increase of 60.7%. Therefore, for the design and analysis of drainage improvement, it would be desirable to construct a sub-catchment distributed network and introduce an unsteady flow analysis that can take flow delays into account.

구성주의 이론에 입각한 학습자 중심교육에 대한 연구

강재원 ( Jaewon Kang ) 현대영미어문학회 2017 현대영미어문학회 춘계학술대회 발표논문집 Vol.2017 No.-

The aim of this study examines the effect of incorporating learner-centered instructional methods within an English-through-English class on college students’ English speaking ability and affective variables toward learning English. In the class, students were supported as they led activities consisting of collaborative studying, class discussion, presentation, and peer assessment. Comparisons of pre and post treatment assessments will reveal improvement in participants’ English speaking ability and attitude. A follow up survey and interview will execute to search participants' satisfaction with the class structure. This study highlights the effectiveness of incorporating learner-centered, constructivist learning principles into university English through-English classes for developing learner speaking ability and improved attitudes toward learning English.

구성주의적 수행평가 워크숍에 참여한 예비 화학교사의 수행평가 과제 개발 과정에서 고려된 교과교육학 지식(PCK) 구성 요소 및 연계의 특징

이재원 ( Jaewon Lee ),류고운 ( Goeun Ryu ),강석진 ( Sukjin Kang ),노태희 ( Taehee Noh ),강훈식 ( Hunsik Kang ) 한국과학교육학회 2018 한국과학교육학회지 Vol.38 No.4

이 연구에서는 구성주의적 수행평가 워크숍에 참여한 예비 화학교사가 수행평가 과제 개발 과정에서 고려하는 교과교육학 지식(PCK) 구성 요소와 구성 요소 사이 연계의 특징을 분석하였다. 8명의 예비교사가 연구에 참여하였고, 이들은 3주간의 구성주의적 수행평가 워크숍 후 수행평가 과제를 개발하였다. 예비교사의 수행평가 과제 개발 과정을 조사하기 위해 발성 사고법을 사용하였고, 활동을 녹음 및 녹화하였으며 반구조화된 면담을 통하여 자료를 수집하였다. 분석 결과, 개별 수행평가 과제 개발 과정의 구상 단계에서는 과학 평가, 교수 전략, 학생, 내용에 관한 지식이 거의 동일한 비율로 나타났고, 구체화 단계에서는 과학 평가에 관한 지식이 주로 나타났다. 조별 논의 과정에서는 과학 평가, 교수 전략, 학생에 관한 지식의 비율이 거의 같았다. 그러나 과학교육과정에 관한 지식과 하위 요소 중 과학 과정 지식을 고려한 경우는 드물었다. PCK 구성 요소 사이의 연계는 개별 수행평가 과제 개발 과정의 구상 단계에서 과학 교수 전략에 관한 지식을 중심으로 나타났고, 구체화 단계와 조별 논의 과정에서는 학생에 관한 지식을 중심으로 나타났다. 그러나 과학교육과정과 내용에 관한 지식이 다른 PCK 구성 요소와 연계되는 경우는 적었다. 연구 결과를 바탕으로 교육적 시사점에 관하여 논의하였다. In this study, we investigated the characteristics of the pedagogical content knowledge (PCK) components and their integrations in the processes of developing performance assessment tasks of pre-service chemistry teachers who participated in the constructive performance assessment workshop. Eight pre-service teachers participated in this study. After three weeks of the constructivist performance assessment workshop, they developed their own performance assessment tasks. The think-aloud method was used to investigate their developing processes. Their activities were recorded and videotaped, and semi-structured interviews were also conducted. The analysis of the results revealed that the PCK component considered in the planning step showed similar frequencies for assessment, instructional strategies, students, and subject matter components. In the embodying step, assessment component was most frequent. In the discussion step, the frequencies for assessment, instructional strategies, and students components were similar. However, curriculum component and the subcomponent of science process skill were rarely used. The integrations among the PCK components were found to be centered on the instructional strategies component in the planning step and the students component in the embodying and discussion step. However, curriculum and subject matter components were rarely integrated with other PCK components. On the basis of the results, educational implications are discussed.

회귀분석 모델-최적화 알고리즘과 기계 학습을 활용한 열해석 모델 보정 기법

강재원(Jaewon kang),조진연(Jin Yeon Cho),김정호(Jeong Ho Kim) 한국항공우주학회 2022 한국항공우주학회 학술발표회 논문집 Vol.2022 No.11