Development and characterization of injectable human keratin based hydrogels

박나정,이윤기,최수지,박경민,황유식,박기동 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Injectable hydrogels have received great attention for tissue engineering because of minimally invasive procedure, easy to handle, capability of encapsulating bioactives. Recently, keratin extracted from human hair has emerged as fascinating biomaterials due to its excellent biocompatibility, biodegradability, low immune reaction and plenty of resource. Despite of these advantages, the low solubility of keratin in aqueous solutions significantly hinders its widespread applications. In this study, in situ-forming keratin based hydrogels were developed. Keratinpoly(ethylene glycol) (PEG)-tyramine (KPT) conjugates were synthesized by grafting tyramine to keratin using a PEG linker. KPT hydrogels were prepared by HRP catalyzed reaction and their physico-chemical properties were characterized. Finally in vitro cell-cytotoxicity test showed great biocompatibility. From these results, we can suggest the in situ forming KPT hydrogels have a great potential for tissue engineering application.

중앙 제어 / 관리 플랫폼을 이용한 차세대 네트워크 구조 및 요구사항

박나정,양진홍,손진혁,전규영,김철수 한국통신학회 2004 한국통신학회 학술대회 및 강연회 Vol.2004 No.12

특성화고등학교 학생의 자아정체감이 진로결정 자기효능감에 미치는 영향

박나정,임나영,이창훈 한국기술교육학회 2017 한국기술교육학회지 Vol.17 No.2

This study examined ego identity and self-efficacy in career decision-making among specialized technical high school students with the aim of proposing preliminary data to suggest ways to improve self-efficacy in career decision-making through establishing proper ego identity. The specific research questions were set as; first, to define the ego identity status in relation to the students’ personal characteristics among specialized technical high school students; second, to describe the status of self-efficacy in career decision-making related to the students’ personal characteristics among specialized technical high school students; and last, to examine the influence of ego identity on self-efficacy in career decision-making among specialized technical high school students. To accomplish such research objectives, the assessment survey was developed after reviewing the theoretical literature on specialized technical high school students’ background, ego identity, and self-efficacy in career decision-making. The survey was comprised of 43 items including personal characteristics (6 items), ego identity (13 items), and self-efficacy in career decision-making (24 items). A total of 990 students from industrial specialized high schools across the country completed the survey, and the responses from 775 students were used for the final analyses after excluding the surveys with unanswered items or untrustworthy responses. Results were as follows: For differences in ego identity in relation to motives of entering specialized technical high school, the group that entered the school because of aptitude and interest and those who entered the school considering the promising prospect of technicians had higher ego identity compared to those who entered the school for economic independence. The group with higher levels of school adaptation and satisfaction showed higher ego identity than those with lower levels of school adaptation and satisfaction. For differences in self-efficacy in career decision-making related to motives of entering the specialized technical high school, the group that entered the school considering promising prospect of technicians had higher level of self-efficacy in career decision-making than those who entered the school for economic independence and those who entered the school for opportunity for special admissions to college. With regard to differences in self-efficacy in career decision-making related to school adaptation and satisfaction, the group that adapted to school very well showed higher level of self-efficacy in career decision-making than those who did not. For differences in self-efficacy in career decision-making related to post-graduation plans, the groups that had plans such as getting a job or going to college had higher level of self-efficacy in career decision-making compared to those without plans. Furthermore, for the influence of ego identity on self-efficacy in career decision-making, the results showed that ego identity had positive associations with all the sub-factors of self-efficacy in career decision-making, and all correlations and coefficients of determination showed a robust statistical significance. Therefore, to enhance self-efficacy in career decision-making, education that could help students better adapt to school, increase satisfaction with the school, and create positive ego identity must precede. 이 연구는 특성화고등학교 학생의 자아정체감과 진로결정 자기효능감에 대해 알아봄으로써 바람직한 자아정체감의 형성을 통해 진로결정 자기효능감 수준을 높일 수 있는 방안을 모색하기 위한 기초 자료를 제공하기 위한 목적으로 수행되었다. 구체적인 연구문제로는 첫째, 특성화고등학교 학생의 개인특성에 따른 자아정체감 수준은 어떠한가, 둘째, 특성화고등학교 학생의 개인특성에 따른 진로결장 자기효능감의 수준은 어떠한가, 셋째, 특성화고등학교 학생의 자아정체감이 진로결정 자기효능감에 미치는 영향은 어떠한가로 설정하여 구명하였다. 연구의 목적을 달성하기 위해 특성화고등학교 학생의 개인특성, 자아정체감, 진로결정 자기효능감에 관련된 이론적 배경을 고찰하여 검사도구를 제작하였다. 설문지는 개인특성(3문항), 자아정체감(13문항), 진로결정 자기효능감(24문항)으로 총 40문항으로 구성하였으며, 전국 공업계열 특성화고등학교 학생 990명을 대상으로 설문조사를 실시하여 무응답이나 불성실한 응답의 설문지를 제외한 775부를 최종 분석에 활용하였다. 연구의 결과는 다음과 같다. 기술인에 대한 미래 전망을 고려하여 특성화고등학교에 진학한 집단과 학교 적응 및 만족도가 높은 집단이 그렇지 않은 집단에 비해 자아정체감 및 진로결정 자기효능감 수준이 높게 나타났다. 또한 자아정체감이 진로결정 자기효능감에 주는 정적인 영향과 상관관계, 설명력 모두 높은 통계값을 기록하였다. 따라서 진로결정 자기효능감의 질적 향상을 위해서는 학생의 학교 적응 및 만족도를 높이고 긍정적인 자아정체감을 형성할 수 있는 교육이 선행되어야 할 것이다.

보의 단면크기에 따른 고강도 철근콘크리트보의 전단강도 특성 연구

박나정,유인근,백승민,김우석,곽윤근 한국복합신소재구조학회 2020 복합신소재구조학회 학술발표회 Vol.2020 No.07

특성화고등학교 학생의 회복탄력성이 진로결정 자기효능감에 미치는 영향

박나정,임나영,이창훈 대한공업교육학회 2018 대한공업교육학회지 Vol.43 No.1

This study examined resilience and career decision-making among specialized technical high school students with the aim of proposing preliminary data to suggest ways to improve self-efficacy in career decision-making through establishing proper resilience. The specific research questions were set as; first, to define the resilience status in relation to the students’ personal characteristics among students; second, to describe the status of self-efficacy in career decision-making related to the students’ personal characteristics among students; and last, to examine the influence of resilience on self-efficacy in career decision-making among specialized technical high school students. To accomplish such research objectives, the assessment survey was developed after reviewing the theoretical literature on specialized technical high school students’ background, ego identity, and self-efficacy in career decision-making. The survey was comprised of 54 items including personal characteristics (3 items), resilience (27 items), and self-efficacy in career decision-making (24 items). A total of 990 students from industrial specialized high schools across the country completed the survey, and the responses from 775 students were used for the final analyses after excluding the surveys with unanswered items or untrustworthy responses. Results were as follows: The group with higher levels of school adaptation and satisfaction showed higher resilience and career decision-making than those with lower levels of school adaptation and satisfaction. Furthermore, for the influence of resilience on self-efficacy in career decision-making, the results showed that resilience had positive associations with self-efficacy in career decision-making, and all correlations and coefficients of determination showed a robust statistical significance. Therefore, to enhance self-efficacy in career decision-making, education that could help students better adapt to school, increase satisfaction with the school, and create positive resilience must precede. 이 연구는 특성화고등학교 학생의 회복탄력성과 진로결정 자기효능감에 대해 알아봄으로써 바람직한 회복탄력성의 형성을 통해 진로결정 자기효능감 수준을 높일 수 있는 방안을 모색하기 위한 기초 자료를 제공하기 위한 목적으로 수행되었다. 연구문제로는 첫째, 특성화고등학교 학생의 개인특성에 따른 회복탄력성 수준 차이는 어떠한가, 둘째, 특성화고등학교 학생의 개인특성에 따른 진로결장 자기효능감의 수준 차이는 어떠한가, 셋째, 특성화고등학교 학생의 회복탄력성이 진로결정 자기효능감에 미치는 영향은 어떠한가로 설정하여 구명하였다. 연구의 목적을 달성하기 위해 특성화고등학교 학생의 배경 현황, 회복탄력성, 진로결정 자기효능감에 관련된 이론적 배경을 고찰하여 검사도구를 제작하였다. 설문지는 개인특성(3문항), 회복탄력성(27문항), 진로결정 자기효능감(24문항)으로 총 54문항으로 구성하였으며, 전국 공업계열 특성화고등학교 학생 990명을 대상으로 설문조사를 실시하여 무응답이나 불성실한 응답의 설문지를 제외한 775부를 최종 분석에 활용하였다. 연구의 결과는 다음과 같다. 1학년이 3학년에 비해 회복탄력성의 긍정성 요소 및 진로결정 자기효능감의 미래계획효능감 요소에서 유의하게 높은 것으로 나타났으며, 학교 적응 및 만족도가 높은 집단이 그렇지 않은 집단에 비해 회복탄력성 및 진로결정 자기효능감의 하위 요인에서 정적인 영향을 미치는 것으로 나타났다. 또한 진로결정 자기효능감에의 경우 아직 진로를 결정하지 못한 집단이 그렇지 않은 집단에 비해 하위 요인에서 부정적인 영향을 주는 것으로 나타났다. 회복탄력성은 진로결정 자기효능감에 있어 52.1%의 설명력을 기록하였다. 따라서 진로결정 자기효능감의 질적 향상을 위해서는 학생의 학교 적응 및 만족도를 높이고 긍정적인 회복탄력성을 형성할 수 있는 교육이 선행되어야 할 것이다.

전단철근비와 보의 단면크기에 따른 고강도 철근콘크리트보의 전단강도 특성 연구

박나정(Park, Na-Jeong),노형진(Noh, Hyung-Jin),유인근(Yu, In-Geun),백승민(Baek, Seung-Min),김우석(Kim, Woo-Suk),곽윤근(Kwak, Yoon-Keun) 대한건축학회 2020 대한건축학회논문집 Vol.36 No.8

The purpose of this study is to investigate the shear strength of high strength reinforced concrete beams according to shear reinforcement ratio and beam section size. A total of twelve specimens were tested and designed concrete compressive strength is 50 MPa. The main variables are shear reinforcement ratio and beam section size fixed with shear span to depth ratio (a/d = 2.5), the tensile reinforcement ratio (ρ = 0.013) and width to depth ratio (h/b = 1.5). The test specimens were divided into three series of H1 (225×338 mm), H2 (270×405 mm) and H3 (315×473mm) respectively. The experimental results show that specimens represent various failure modes such as diagonal tensile failure (DTF), bond failure (BF), shear compression failure (SCF) and flexural compression failure (FCF). In the H1 series, the shear strength increased by 92.0%, 94.1% and 128.4% respectively as the shear reinforcement ratio increased, 103.8%, 138% and 143% respectively in the H2 series, 131.1%, 168.7% and 151.7% respectively in the H3 series. The decreasing rate of shear strength increased as the beam’s effective width increased, which is considered to be due to the size effect. Then, it is shown that the decreasing rate of shear strength increases as d/s increases, and it can be seen that the effect of the size effect increases as the spacing between shear reinforcing bars decreases. As compared to the standard and the proposed equations, theoretical values by proposed equation of Zsutty, Bazant, and Lee has compared relatively well with experimental values.

광대역통합망에서 과금 및 정산을 위한 유연성 있는 아키텍처 모델

박나정(Na-jung Park),황원주(Won-joo Hwang),김철수(Chul-soo Kim) 한국통신학회 2004 한국통신학회 학술대회논문집 Vol.2004 No.7

LSP Congestion Control methods in ATM based MPLS on BcN

김철수,박나정,안귀임,이정태 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.4

보의 유효깊이와 전단철근간격에 따른 철근콘크리트보의 전단강도에 관한 연구

유인근,박나정,백승민,김우석,곽윤근 대한건축학회 2020 대한건축학회논문집 Vol.36 No.11

Although many studies have been conducted on some factors (i.e., tensile reinforcement ratio, shear span-to-depth ratio, concrete compressivestrength, and beam width-to-depth ratio) affecting the shear strength of concrete, studies on the effect of the cross-sectional size on the shearstrength have not been achieved. For this reason, the purpose of this study is to conduct a study on the shear strength of reinforced concretebeams according to beam effective depth and shear reinforcement spacing. Based on these experimental results, the authors intend to usethem as basic data for shear design of reinforced concrete beams by comparing and analyzing theoretical values by standard equations suchas KBC 2016 and ACI 318-19 as well as proposed equations. As a result, each series of No.2 specimens (SH1-2, SH2-2 and SH3-2) with max = 0.67d (d/s = 1.5) similar to  max= 0.7d by the CSA standard is 1.00 to 1.41. It was found that the current standard for shear bars =d/2 may be somewhat relaxed, but additional studies are needed to reflect this in the Korean Building Code. 본 연구에서는 보의 유효깊이와 전단철근간격에 따른 철근콘크리트보의 전단강도에 관한 영향을 분석하기 위해 인장철근비(ρ=0.025), 폭 대 깊이 비(h/b=1.5)와 전단경간비(a/d=2.5)를 일정하게 하였고, 단면의 크기와 전단철근비를 변수로 하여 전단실험을 하였다. 실험결과를 분석하여 다음과 같은 결론을 도출하였다. KBC2식을 기준으로 전단철근을 배근한 시험체만을 대상으로 한 경우에는, 이론값에 대한 실험값의 비가 0.85 ~ 1.29로 나타났다. 특히, CSA 기준에서 요구하는 = 0.7d와 유사한 S=0.67d (d /s=1.5)인 각 시리즈 2번 시험체(SH1-2, SH2-2, SH3-2)에서는 1.17 ~ 1.29로 나타나 전단철근에 대한 현행기준 = d /2는 다소 완화시켜도 될 것으로 판단되지만, 이를 기준에 반영하기 위해서는 추가적인 연구가 필요하다.

Softswitch와 제어 네트워크간의 호 제어 방안 연구

양진홍,박나정,손진혁,김철수 한국통신학회 2004 한국통신학회 학술대회 및 강연회 Vol.2004 No.12