북한산 둘레길과 복합신소재 구조물이 갖는 특성

박기연 한국복합신소재구조학회 2011 복합신소재학회논문집 Vol.2 No.3

캡플레이트를 이용한 장스팬용 춤이 깊은 데크의 휨성능 개선

박기연,남윤선,최영환,김영호,최성모 한국강구조학회 2013 韓國鋼構造學會 論文集 Vol.26 No.5

Slim floor system using deep decks has been developed and employed in Europe to reduce the floor height of steelstructures. Although long span buildings involving the issue of reducing floor height are being increasingly built in Korea,employing deep decks in more than 7m long span structures is likely to cause problems associated with excessive deflection. This study is applied to the long-span concrete casting of the deep deck plate usability of deflection due to bending andtorsional instability of open cross-section, as a way to improve the problem of cap plates are suggested, and the optimumlength of reinforcement and location are derived from theoretic estimation. The cap plates are placed on the deep decks withregular intervals to overcome the instability of open sections, improve the stiffness of the sections and control the deflectionat the centers. The improvement in flexural capacity associated with the location of the cap plates and the length ofreinforcement are verified through analysis and test. 철골구조의 층고를 절감을 위해 유럽을 중심으로 춤이 깊은 데크를 사용한 슬림플로어 공법이 개발되어 적용되고 있다. 국내에서도 장스팬과 층고절감을 요구하는 건물이 증가하고 있지만 7m이상 장스팬에 춤이 깊은 데크를 적용 시 과도한 처짐에 의한 사용성 문제를초래한다. 따라서 본 연구는 장스팬에 적용되는 춤이 깊은 데크의 콘크리트 타설시 처짐의 사용성 및 개방형 단면의 불안정성에 의한 휨비틀림 등의 문제를 개선하는 방안으로 Cap형태의 plate(이하 '캡 플레이트')를 두가지 형태(Flat, Hat)로 개발하고 보강 길이와 위치의 최적화를 이론적 계산을 통해 도출하였다. 이 캡플레이트를 춤이 깊은 데크의 골상부에 일정 간격으로 설치하여 상부 개방형 불안전성을 극복하고단면의 강성을 증대시켜 중앙부 처짐을 제어하고자 한다. 캡 플레이트의 설치위치와 보강길이에 따른 휨서능 개선의 효과를 해석과 실험을 통해 검증하고자 한다.

육군 사단급 복무 부적응 병사 치유를 위한 그린캠프 운영 개선방안

박기연,남궁승필,박상혁 국제문화기술진흥원 2019 The Journal of the Convergence on Culture Technolo Vol.5 No.4

This thesis analyzed descriptive statistically 202 duty maladjustment soldiers' questionnaire about satisfaction and mind change while taking course in Green camp in year 2017 to 2018, and 350 military leaders about Green camp programs about managers' general matters, duty maladjustment soldiers' general matters, about using Green camp programs. March 17th 2019 Military Manpower Administration announced total 6,214 consideration candidates of nonconformance on basic active service, 98.4% of them, which is 6,118 soldiers, are early discharged while not be able to finish their full duty. 66% (4,014 soldiers) of them are suffering from duty maladjustment. Green camp has been managed through the history of 'Vision Camp' in 2003, 'Healing Camp' in 2009 and 'Green Camp' since July, 2011. Currently, 17 Green camps are established in each military corps and each division in Second Operational Command. However, due to difference in care and capacity of lecturers and programs, each Green camp needs extra care. 본 연구는 2017년에서 2018년도 간에 그린캠프에 입소한 202명의 복무 부적응 인원들이 교육 후의 만족도와 자신 생각의 변화에 대한 설문과 간부 350명 대상 그린캠프의 운영현황에 대하여 분석하였다. 또한, 간부들의 일반적인 사항, 그린캠프 입소 병사에 관한 사항, 그린캠프 이용에 관한 사항, 소속부대 내 병사상담 관련 사항에 대해 기술통계로 분석하였다. 2019년 3월 17일 국방부는 6,214명의 현역복무 부적합 인원들 중에 6,118명의 98.4%에 달하는 인원들이 군 복무를 마무리하지 못하고 전역조치 되었다는 것을 식별되었으며, 이들 중 66%에 달하는 4,014명이 군인원들이 군 복무 부적응을 경험하였다. 따라서 군 복무 부적응으로 전역조치 되는 병사를 조기에 식별하여 민간 전문가를 이용한 교육과 진로선택 등 다양한 방법을 적용하고 필요시에 민간 전문병원을 통하여 적시적인 교육과 치료로 정상적인 군 생활을 마치고 전역할 수 있도록 하여야 할 필요성이 있다.

Characterization and Transcriptional Response of Ecdysone Receptor Gene in the Mud Crab Macrophthalmus japonicus: Effects of Osmotic Stress and Endocrine Disrupting Chemicals

박기연,김원석,곽인실 한국해양과학기술원 2019 Ocean science journal Vol.54 No.4

The ecdysone receptor (EcR) induces hormonal pathways by binding ecdysteroids to other nuclear receptors for development, reproduction, and molting processes. To further understand the role of EcR in polluted environments, we characterized EcR and assessed the transcriptional responses of the EcR gene to osmotic stress, and to endocrine disrupting chemicals (EDCs) such as bisphenol A (BPA) and di-(2-ethylhexyl) phthalate (DEHP) in the intertidal mud crab Macrophthalmus japonicus. Phylogenetic analysis showed that the ligand binding domain of M. japonicus EcR formed two different clusters among crab species. Osmotic stress prompted different expression patterns of EcR mRNA in M. japonicus crabs under low and high salinities. BPA exposure induced significant up-regulation of EcR as early as day 1 in M. japonicus gills and hepatopancreas. However, the expression levels of EcR returned to similar, or lower, levels as controls, by days 4 and 7. In contrast, EcR mRNA expression was significantly induced in M. japonicus gills and hepatopancreas exposed to most of the DEHP concentrations over all exposure times. Hepatopancreatic tissue is more sensitive than gill tissue in terms of EcR gene responses to EDCs. Taken together, these results suggest that the role of EcR in endocrine protection may involve different processes according to the type of EDCs and up-regulatory responses of the EcR transcript could be used as an indicator for detecting changes in hormonal systems caused by environmental stressors.

두께에 따른 GI Cement의 색상 변화 및 각 Shade 내의 색상 변화 추이도

박기연,신동훈 大韓齒科保存學會 1997 Restorative Dentistry & Endodontics Vol.22 No.2

Glass ionomer cements, which had been developed in 1972, were widely used as an agent for cementation, base, pit and fissure sealant, and esthetic filling material with the advantages of excellent biocompatibility, anti-cariogenic fluoride release. Specimens were made to evaluate toe color change of Glass ionomer cement with a newly developed improved Fuji Ⅱ LC. Specimens for color change study with cement thickness of 1, 2, 3mm were made and those for the study of color shift pattern were made with the assumption that new mid-shade can be made by mixing of equal amount of both shades in 2mm thickness. After 24 hours in a 37℃ incubator, CIELAB color space were evaluated with a spectrophotometer. The results were as follows; 1. All specimens discolored to dark and blue with an increased thickness in all shades(p<0.05). 2. There were significant a* space(red-green direction) changes in every A, B, C, D shade series except the erlationship between 1mm and 2mm thickness groups in B shade series. But the changes were irregular, e.e., each shade series has its own pattern. 3. Each shade series showed its own specific color shift pattern in all L*, a*, b* spaces. 4. B shade series showed less amont of changes in Δ±E than those of A and C shade series(p<0.05), but there was no significant difference in ΔE within each shade series.

Health-Risk assessment research in freshwater-seawater indicator organism

박기연,곽인실 환경독성보건학회 2020 한국독성학회 심포지움 및 학술발표회 Vol.2020 No.9

Characterize and Gene Expression of Heat Shock Protein 90 in Marine Crab Charybdis japonica following Bisphenol A and 4 -Nonylphenol Exposures

박기연,곽인실 환경독성보건학회 2014 환경독성보건학회지 Vol.29 No.-

Objectives Heat shock protein 90 (HSP90) is a highly conserved molecular chaperoneimportant in the maturation of a broad spectrum of protein. In this study, an HSP90gene was isolated from Asian paddle crab, Charybdis japonica, as a bio-indicator tomonitor the marine ecosystem. Methods This work reports the responses of C. japonica HSP90 mRNA expression tocellular stress by endocrine disrupting chemicals (EDCs), such as bisphenol A (BPA) and4-nonylphenol (NP) using real-time. reverse transcription polymerase chain reaction. Results The deduced amino acid sequence of HSP90 from C. japonica shared a highdegree of homology with their homologues in other species. In a phylogenetic analysis,C. japonica HSP90 is evolutionally related with an ortholog of the other crustacean species. The expression of HSP90 gene was almost distributed in all the examined tissuesof the C. japonica crab but expression levels varied among the different body parts of thecrabs. We examined HSP90 mRNA expression pattern in C. japonica crabs exposed toEDCs for various exposure times. The expression of HSP90 transcripts was significantlyincreased in C. japonica crabs exposed to BPA and NP at different concentrations for 12,24, 48 and 96 hours. The mRNA expression of HSP90 gene was significantly induced ina concentration- and time-dependent manner after BPA or NP exposures for 96 hours. Conclusions Taken together, expression analysis of Asian paddle crab HSP90 gene provideduseful molecular information about crab responses in stress conditions and potentialways to monitor the EDCs stressors in marine environments.

직결나사 연결 접합부에 관한 구조성능평가 연구

박기연,전상현,김영호,최성모 한국강구조학회 2013 韓國鋼構造學會 論文集 Vol.26 No.5

As the deep deck plate has the shape of open cross section, It can cause structural problems such as bendingtorsions due to instability of the section. There are a number of fasteners types which are frequently used on light gage steeldiaphragms such as bolts, rivets, welds, and screws. In this study, the structural capacity of the self drilling screwconnection between the deep deck and the reinforced cap plate was evaluated by experimental variables such as thearrangement method, numbers of screw, pitch of screw, and head plate thickness. 춤이 깊은 골형 데크는 그 단면의 형태가 개방형 단면(開斷面)으로 단면의 불안정성에 의한 휨비틀림 등의 구조적 문제를 일으킬 수 있다. 박판의 냉간성형강인 데크와 캡플레이트의 접합에 사용되는 연결재(파스너)는 볼트, 리벳, 용접 그리고 나사 접합이 있다. 이 연구는 냉간성형강을 사용한 춤이 깊은 데크와 보강용 캡플레이트간의 직결나사 접합부에 관한 실험적 연구로, 직결나사 접합부의 파괴거동과최대내력에 영향을 주는 직결나사 배치방법, 직결나사 수, 직결나사 간격 그리고 직결나사 머리밑판의 두께변화를 실험변수로 하여 국외 설계기준식 비교·분석하고자 한다.

GNE 근병증이 있는 환자에게서 반복적으로 발생하는 케톤산증 1예

박기연,김양균 대한내과학회 2023 대한내과학회 추계학술대회 Vol.2023 No.2

Transcriptional responses of heat shock protein 90 (HSP90) and heat shock protein 83 (HSP83) genes by salinity changes in the intertidal crab Macrophthalmus japonicus

박기연,곽인실 환경독성보건학회 2019 한국독성학회 심포지움 및 학술발표회 Vol.2019 No.10