내수재해 위험지구 평가 방법과 그 적용

이창준, 김민환 호남대학교 산업기술연구소 2014 녹색산업연구 Vol.20 No.1

풍수해는 매년 증가하고 있으며 그 강도도 커지고 있는 실정이다. 풍수해의 유형은 하천재해, 내수재해(호우재해), 사면재해, 토사재해, 바람재해로 구분할 수 있다. 그 중에서 내수재해에 대한 평가 방법을 소개하고 그 방법을 D군에 적용하여 내수재해 위험지구를 선정하였다. D군의 내수재해 위험요인을 분석한 결과, 우수관거 관련 문제, 외수위 상승으로 인한 피해, 우수처리 시설 문제, 주변보다 지반고가 낮은 문제, 토석류의 유입으로 하천 소통 능력 저하 등의 2차적 침수피해 등으로 분석되었다. D군의 내수재해 위험지구를 위험요인별로 분류하여 제시하였다. Storm and flood damage is increasing every year and its strength is large in Korea. Type of storm and flood damage can be classified with river disasters, domestic disasters(heavy rain disaster), slope disaster, landslides disaster, and wind disaster. A method of assessment for domestic disaster was introduced, and applied to the D-district. The risk factors for domestic disaster of D-district are insufficient channel-section problem of sewer, damage by rising water levels in river, plant problems of rainfall treatment, problems surrounding the lower elevation, and reduced cross-section due to debris flows. Domestic disaster risks for D-district were classified into several type. Factors for the disaster risk was presented. Key words: Storm and flood damage, Domestic disasters, Flood damage

하도 버퍼링에 의한 침수구역 설정 방법과 그 적용

고성찬・이창준・김민환 호남대학교 산업기술연구소 2014 녹색산업연구 Vol.20 No.1

집중호우가 발생할 때 유역의 특성을 고려한 재해 대책이 필요하다. 침수구역을 객관적으 로 평가하기 위해 지형 특성과 지형 정보를 활용하였다. 적정한 침수구구역의 설정은 침수 방지 시설을 갖추기 위한 선행 작업이다. 이 작업을 위해 최근에 개발된 Arc-Gis를 이용하 여 침수구역을 설정하였다. 이 방법을 증암천 유역에 적용하여 위험구역을 설정하였다. There is require disaster prevention considering the characteristics of the watershed when heavy rains occur. We have to objectively evaluate the flooded area using topographic characteristics and geographic information. A set of appropriate flooded area should be preceded for facilities of flood prevention. We have established a flooded area using the latest version Arc-Gis. This software was applied to the classification for flood hazard area at Jeungam-stream basin.

Transient Engine Test Bed를 이용한 가솔린엔진의 F/E 및 Emission개선에 관한 연구

이상수(Sangsu Lee),이창준(Changjun Lee),이근봉(Keunbong Lee),이문식(Moonsig Lee),이정근(Jeongkeun Rhee) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The fuel economy and emissions in a developing port injection gasoline engine with manual transmission were studied using a transient engine test bed. Because the fuel economy and emissions in the first few minutes during engine warmup show great importance, the first ECE cycle in NEDC mode was simulated. To match the fuel economy and emission levels with the roller bed test results, driver model on clutch and acceleration pedal actions were thoroughly adjusted to match engine speed and engine load of the vehicle. The faster catalyst light-off was investigated by varying crank-to-run air-fuel ratio and idle spark timing. and results showed that slightly lean air fuel ratio was more effective in heating lip the catalyst than retarding idle spark timing in terms of fuel economy. The additional engine EMS calibrations were performed to improve cruise operation points and idle regions using DOE method with L9 orthogonal test array. The overall results showed that both the fuel economy and emissions were improved during first ECE cycle in the NEDC mode test by the EMS calibration performed in this study.

Capturing information on technology convergence, international collaboration, and knowledge flow from patent documents: A case of information and communication technology

Lee, Changjun,Kogler, Dieter Franz,Lee, Daeho Elsevier 2019 Information processing & management Vol.56 No.4

<P><B>Abstract</B></P> <P>In addressing persistent gaps in existing theories, recent advances in data-driven research approaches offer novel perspectives and exciting insights across a spectrum of scientific fields concerned with technological change and the socio-economic impact thereof. The present investigation suggests a novel approach to identify and analyze the evolution of technology sectors, in this case, information and communications technology (ICT), considering international collaboration patterns and knowledge flows and spillovers via information inputs derived from patent documents.</P> <P>The objective is to utilize and explore information regarding inventors’ geo-location, technology sector classifications, and patent citation records to construct various types of networks. This, in turn, will open up avenues to discover the nature of evolutionary pathways in ICT trajectories and will also provide evidence of how the overall ICT knowledge space, as well as directional knowledge flows within the ICT space, have evolved differently. It is expected that this data-driven inquiry will deliver intuitive results for decision makers seeking evidence for future resource allocation and who are interested in identifying well-suited collaborators for the development of potential next-generation technologies. Further, it will equip researchers in technology management, economic geography, or similar fields with a systematic approach to analyze evolutionary pathways of technological advancements and further enable exploitation and development of new theories regarding technological change and its socio-economic consequences.</P>

Interaction of ε-L-β-lysine as a tail analogy of tallysomycin-A to a double helical DNA oligonucletide d(CGCTTCGAAGCG)2

Changjun Lee,원호식 한국자기공명학회 2007 Journal of the Korean Magnetic Resonance Society Vol.11 No.2

During the screening of material which has the antimicrobial activity against aminoglycoside-resistant bacteria, A new material -(L-β-lysine) polypeptide from a culture medium of Streptomyces sp.(DWGS2) was isolated, and the structure and the physicochemical properties of the new material were elucidated. The new material was separated by column chromatography of the culture medium using Dowex1×2, Silica gel, and Sephadex LH20 etc. The structure and molecular weight were determined with the data of NMR, MALDI mass, and ESI mass experiments. And the monomer obtained by hydrolysis of the new material with 6N-HCl was identified as a L-β-lysine(T2), which is a tail of bleomycin. As tail-region analogy, T2(β-lysine derivatives from streptomyces) interactions with a self-complementary oligonucleotides, d(CGCTTCGAAGCG)2, was investigated by NMR.

Development of Operator Training System in Petrochemical Plant(RDS) by Integrating Process and Accident Simulation in Real Time

Changjun Ko(고창준),Yongseok Lee(이용석),Hodong Lee(이호동),Dongju Kang(강동주),Youngsub Lim(임영섭) 한국가스학회 2018 한국가스학회 학술대회논문집 Vol.2018 No.5

Remarkably enhanced adhesion of coherently aligned catechol-terminated molecules on ultraclean ultraflat gold nanoplates

Lee, Miyeon,Park, Changjun,Lee, Hyoban,Kim, Hongki,Kim, Sang Youl,In, Insik,Kim, Bongsoo IOP 2016 Nanotechnology Vol.27 No.47

<P>We report the characterization and formation of catechol-terminated molecules immobilized on gold nanoplates (Au NPLs) using N-(3,4-dihydroxyphenethyl)-2-mercaptoacetamide (Cat-EAA-SH). Single-crystalline Au NPLs, synthesized using a one-step chemical vapor transport method, have ultraclean and ultraflat surfaces that make Cat-EAA-SH molecules aligned into a well-ordered network of a large-scale. Topographic study of the catechol-terminated molecules on Au NPLs using atomic force microscopy showed more orderly orientation and higher density, leading to significantly higher adhesion as observed from local force–distance curves than those on other Au surfaces. These coherently aligned catechol-terminated molecules on the atomically smooth gold surface led to significanty more reproducible and thus more physico-chemically meaningful measurements than was possible before by employing rough gold surfaces.</P>

Intra-industry innovation, spillovers, and industry evolution: Evidence from the Korean ICT industry

Lee, Changjun,Kim, Jang Hyun,Lee, Daeho Elsevier 2017 Telematics and Informatics Vol.34 No.8

<P><B>Abstract</B></P> <P>Companies innovate themselves to survive competition, and successful innovations are transferred to the industry as a whole through imitation. In this paper, the technical efficiency (TE) of the Korean information and communication technology (ICT) industry is estimated through stochastic frontier analysis, and the efficiencies from 2000 to 2013 are compared through meta-frontier analysis. In addition, by analyzing the effect of innovations that move the production function up on the TE and the meta-frontier efficiency through the two-stage least square model, this paper investigates the effects of innovation on other companies in the industry in the short- and long-term and how the industry evolves accordingly. As a result, sudden inflation of the meta-technology ratio caused by a few innovative firms automatically lowers the average TE. However, the innovation spills over intra-industry by the efforts of other firms trying to reach around the innovation (i.e., imitation). This recovers other firms’ TE and increases meta-frontier efficiency. In addition, this paper provides theoretical and practical implications of the results.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper estimates technical efficiency of the Korean ICT industry. </LI> <LI> It compares the efficiency of firms using meta-frontier analysis method. </LI> <LI> It investigates the effects of innovation on other firms. </LI> <LI> It also investigates how the industry evolves accordingly. </LI> </UL> </P>

Distinct Features of Brain-Resident Macrophages: Microglia and Non-Parenchymal Brain Macrophages

Lee, Eunju,Eo, Jun-Cheol,Lee, Changjun,Yu, Je-Wook Korean Society for Molecular and Cellular Biology 2021 Molecules and cells Vol.44 No.5

Tissue-resident macrophages play an important role in maintaining tissue homeostasis and innate immune defense against invading microbial pathogens. Brain-resident macrophages can be classified into microglia in the brain parenchyma and non-parenchymal brain macrophages, also known as central nervous system-associated or border-associated macrophages, in the brain-circulation interface. Microglia and non-parenchymal brain macrophages, including meningeal, perivascular, and choroid plexus macrophages, are mostly produced during embryonic development, and maintained their population by self-renewal. Microglia have gained much attention for their dual roles in the maintenance of brain homeostasis and the induction of neuroinflammation. In particular, diverse phenotypes of microglia have been increasingly identified under pathological conditions. Single-cell phenotypic analysis revealed that microglia are highly heterogenous and plastic, thus it is difficult to define the status of microglia as M1/M2 or resting/activated state due to complex nature of microglia. Meanwhile, physiological function of non-parenchymal brain macrophages remain to be fully demonstrated. In this review, we have summarized the origin and signatures of brain-resident macrophages and discussed the unique features of microglia, particularly, their phenotypic polarization, diversity of subtypes, and inflammasome responses related to neurodegenerative diseases.

Analyzing Characteristics of Construction Complaints with Construction Project Type

Lee, Ju-Hui,Lee, Changjun,Yun, Sungmin Korea Institute of Construction Engineering and Ma 2023 한국건설관리학회 논문집 Vol.24 No.3

Conflicts in a construction project not only make negative impacts on project performance such as schedule delay or cost overrun but also require social cost to resolve the conflicts. Although the conflict needs a preemptive management because a conflict usually begins with a complaint, existing studies have focused on conflict resolution after it occurs. This study identifies and categorizes complaints which mainly appear in the construction projects. Those complaints were evaluated and quantified in terms of occurrence frequency and potential to conflict through a questionnaire survey with industry experts. Using the survey results, this study examines the characteristic of complaints in linear project and clustered project, and analyzes what kind of complaints occur by project type. As the results, this study derives the complaints with high potential to the conflicts that should be managed first during managing a construction project in each project type.