콘크리트에 표면매입 보강된 FRP판의 전단키 및 연단거리 효과

서수연 한국구조물진단유지관리공학회 2016 한국구조물진단유지관리공학회 논문집 Vol.20 No.1

본 연구에서는 콘크리트에 표면매입된 FRP판의 부착거동에서, 전단키와 연단거리의 효과를 관찰하기 위한 부착시험을 실시하였 다. 실험에서의 주요변수는 전단키의 위치, 형태 그리고 연단길이이다. 규격 3.6 ㎜×16 ㎜의 FRP를 400 ㎜×200(300) ㎜×400 ㎜ 규격의 콘크리 트 블록에 매입하고 에폭시로 고정시켜서 실험변수에 따라 총 10개의 부착실험체를 제작하였다. FRP의 연단에 인장력을 가한 뒤 파괴시까지 실험을 실시하고 하중을 기록하였으며, 미끄러짐과 FRP의 인장변형량을 기록하였다. 실험으로부터, 전단키의 위치는 가력부에서 멀리 떨어 질수록 전단강도가 상승하는 것으로 나타났으며, 전단키의 직경이 커질수록 내력이 저하되는 것으로 나타났다. 특히 전단키가 일정 이상의 규 격이 되면 전단키가 없는 경우에 비하여 내력이 저하되어 오히려 부착강도에 부정적인 영향을 미칠 수 있는 것으로 나타났다. NSM FRP에서 응력장용방향의 연단거리가 길어짐에 따라 동일 부착길이임에도 불구하고 내력이 일부 증가하는 것으로 나타났다. 표면매입 보강된 FRP의 부착실험에서, FRP와 콘크리트사이의 부착-미끄러짐은 전체거동을 지배하는 것으로 나타나므로 이에 따른 과도한 미끄러짐은 설계에 반드시 고려될 필요가 있다. This paper presents a bond test to find the effect of shear key and edge length from the bonded FRP in near surface-mounted(NSM) retrofit using FRP plate. Main parameters in the test are the location and size of shear key and the edge length. For the test, 10 specimens were made by embedding FRP plate of 3.6 ㎜×16 ㎜ into 400 ㎜×200(300) ㎜×400 ㎜ concrete block and fixing it by using epoxy. Tensile load was applied to the FRP of the specimens until failure and was recorded at each load increase. In addition, the bond slip and elongation of FRP were measured during the test. From the test, it was found that the further the shear key located from the loading, the higher strength we could get. The bond strength inversely depended on the size of shear key. Especially, when the size of shear key was to be lagger than certain size, the bond strength decreased to very low value; even less than that of the case without shear key. The bond strength somewhat increased corresponding to the increase of edge length from the bonded end of FRP to loading in spite of same bond length. The bond-slip between FRP and concrete governed overall deformation in the bond test of NSM FRP so that the effect of excessive slip is necessary to be considered in the design.

2000년 NEHRP 기준의 프리캐스트 콘크리트 구조에 관한 내진 설계 규정

서수연,문정호,이리형 한국콘크리트학회 2001 콘크리트학회지 Vol.13 No.3

영유아 수면 개입에 대한 빅데이터 분석 접근: 최신 동향

서수연 한국아동학회 2021 한국아동학회 학술발표논문집 Vol.2021 No.11

고려시대의 歌舞百數와 불교

서수연 서울대학교 인문대학 예술문화연구소 2000 예술문화연구 Vol.10 No.-

악몽장애 선별을 위한 반구조화된 임상면담도구 개발 및 타당화

서수연 대한수면연구학회 2021 Journal of sleep medicine Vol.18 No.1

Objectives: Nightmare disorder is highly prevalent in clinical settings and is highly comorbid with posttraumatic stress disorder (PTSD). In the current study, we aimed to develop and validate a semi-structured interview based on the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders-fifth edition for diagnosing nightmare disorder. Methods: We developed a Semi-Structured Clinical Interview for Nightmare Disorder (SCIN) in five steps: we interviewed 100 females (mean age, 24.6±5.88 years) using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5); Structured Clinical Interview for DSM-IV Axis 1 Disorders, Research Version (SCID-I); and self-report questionnaires for nightmares (Disturbing Dream and Nightmare Severity Index, DDNSI), depression, state anxiety, trait anxiety, suicidal ideation, and insomnia. Two independent raters assessed the responses of the interviewees. The interrater reliability for the SCIN was calculated. Pearson’s correlation coefficient was used to assess convergent validity between SCIN and the DDNSI. Chi-square analyses were conducted to compare prevalence of PTSD based on nightmare disorder diagnosis. Results: Among the participants, 42% were diagnosed with nightmare disorder, 15% had subthreshold nightmare disorder, and 43% did not have nightmare disorder. Interrater reliability was moderate (Kappa=0.707, p<0.001). The semi-structured clinical interview showed good convergent validity with the DDNSI (r=0.639, p<0.001). Additionally, individuals who were identified as having nightmare disorder had higher levels of depression, state anxiety, trait anxiety, suicidal ideation, and insomnia (p<0.001). Based on the PTSD diagnosis using CAPS-5, the nightmare group had a higher proportion of PTSD diagnoses than the no-nightmare group (26.2% vs. 8.6%, respectively; χ2=38.41, p<0.001). Conclusions: The semi-structured clinical interview for nightmare disorder appears to have good reliability and validity and can be used in clinical settings.

내측두엽 뇌전증 수술에서 수술 중 신경계감시로 내포 뇌경색증 조기발견

서수연,이용덕,백재승,이채영 대한신경과학회 2020 대한신경과학회지 Vol.38 No.4

Intraoperative neurophysiological monitoring (INM) is underutilized during the anteromesial temporal resection (AMTR) in epilepsy surgery. Herein we report a case with intraoperative capsular infarction which was early detected by INM. Among the modalities of INM, left motor evoked potentials (MEP) showed suddenly decreased amplitude of compound muscle action potentials, after the electrocoagulation in left mesial temporal areas. Postoperative neurologic and MRI findings were well correlated to the intraoperative MEP features. We also discuss the usefulness of INM during the AMTR.

FRP판으로 휨 보강된 철근콘크리트 보의 장기거동

서수연,트랜 하이반,김강수,윤현도,이건철 대한건축학회 2023 대한건축학회논문집 Vol.39 No.3

The purpose of this study is to evaluate the long-term behavior of RC beams reinforced by fiber reinforced polymer (FRP) strip such asnear-surface mounted retrofit (NSMR) and externally bonded retrofit (EBR). The 30% loads of nominal strength of the RC beams wereapplied and continued for up to 49 days. The loads were increased up to 55% of the nominal strengths of RC beams at 50 days afterperforming flexural retrofit by using FRP with the planned retrofit methods and have been kept for almost one year. During all loadingperiods, the deflections and the strains of rebars and FRPs were measured at least once every week. The long-term behavior of all specimenswas evaluated and the deflection variations were predicted by considering the long-term effect on the nonlinear sectional analysis result of thereinforced RC beams. As a result, in the specimen reinforced with partially de-bonded NSM FRP, the strains of the FRP strip were notconcentrated on the center of the beam and the magnitude at the center was less than that with the fully bonded FRP. In addition, it ispossible to properly simulate the deflections of the beams strengthened with FRP exposed to a long-term load by considering the long-termeffect on the sectional analysis result. 본 연구에서는 FRP판으로 표면매립과 표면부착 보강된 RC 보들의 장기거동을 평가하고자 한다. RC 보에 공칭강도의 30%에 해당하는 하중을 가력하여 42일을 지속시킨 후, 하중 작용상태에서 계획된 보강방법에 따라 FRP 판으로 휨보강하고 1주일의 양생기간을 거쳐 50일째에는 보강후 공칭강도의 55%로 하중을 증대시키고 약 1년동안 하중을 유지시켰다. 모든 가력기간동안의 처짐과 인장철근 및 FRP의 변형률을 1주일에 최소 1회이상 계측하였다. 모든 실험체의 장기거동을 평가하였고 단면해석결과에 장기재하 효과를 고려하여 처짐의 변화를 평가하였다. 그 결과, 부분 비부착 FRP로 표면매립보강된 실험체는 비부착구간에서 FRP 변형률이 보의 중앙에 집중되지 않음에 따라, 중앙부 변형률이 완전부착인 경우에 비하여 낮게 나타났다. 또한 단면해석결과에 장기거동 효과를 고려함으로써 장기하중에 노출된 FRP 보강 RC 보의 처짐을 적절하게 예측할 수 있는 것으로 나타났다.

ALC block 벽체의 횡력에 대한 구조성능

서수연 忠州大學校 2002 한국교통대학교 논문집 Vol.37 No.2

The advantages of ALC products with higher insulating and fire-resistant properity are to reduce the term of construction work and the construction cost. Recently, their usefulness are very widely increased in the building constructions as the structural or nonstructural elements. Block wall is a type of ALC member broadly used in the building construction. The objective of this paper is to estimate the structural performance of the ALC block walls by the experimental study. The shear capacity and crack pattern of infilled ALC block wall are verified. From the study, it was shown that the cracks were initiated from the mortar and extended to the mortar line, even though the compressive strength of mortar was more than three times of ALC block.

한국 칠기의 발전과정과 진흥 정책 연구

서수연,이병종 한국디자인문화학회 2018 한국디자인문화학회지 Vol.24 No.4

한국칠기는 일제강점기를 기점으로 진행된 타율적개발정책으로 고유쓰임이 이어지지 못했고, 전통제작기술의 단절과 기술자들의 소멸로 자율적 자리매김을하지 못하였다. 특히 일본수요를 채우기 위한 나전칠기 위주 개발로 칠기 고유의 양식은 소멸되고, 일본형식의 두꺼운 칠에 자개가 화려하게 장식된 나전칠기가 그 자리를 대신하게 된다. 한국전쟁시기 옻칠의 대체 도료인 ‘카슈’가 도입되며, 한국칠기는 쇠퇴한다. 또한 일제강점기 자리 잡은 나전칠기 제작형식은 뒤이은 미군정, 대한민국정부 수립 시기까지 변화 없이유지된다. 이후 추진된 정부의 산업화 정책과 올림픽특수에서도 일제강점기 나전칠기 제작원형은 고수된채 관광기념품으로 개발되며 그 경향은 현재에 이른다. 하지만 2000년대 이후 정부 및 업계의 칠기의 재인식과 시장 변화가 시작되고, 2010년대 새로운 칠기정책의 착수로 현대 한국 사회의 일상 상품으로의 확산이 기대되고 있다. 이 연구를 통해 한국 칠기의 발전과정과 정부의 진흥정책 및 상품화 동향을 분석하여 현대 일상 상품으로의 확산 가능성을 살펴보고자한다. Korean lacquerware failed to continue in its proper use as a result of heteronomous development policy enforced from the period of Japanese colonial rule, and could not establish itself autonomously due to the discontinuance of traditional production techniques and the extinction of its craftsmen. Particularly, the unique style of Korean lacquerware disappeared according to the development of lacquerware revolving around mother-of-pearl lacquerware to meet Japanese demands, and thus was replaced by the style of mother-of-pearl lacquerware richly ornamented with mother-of-pearl in a Japanese-style thick coating of lacquer. During the Korean War, cashew paint, a substitute paint for lacquer, was introduced, and Korean lacquerware further declined. In addition, the mode of fabricating mother-of-pearl lacquerware established during the period of Japanese colonial rule was maintained intact during the subsequent US military rule and until the formation of ROK government. The original fabrication mode of mother-of-pearl lacquerware in the period of Japanese colonial rule was also adhered to in the government’s policy of industrialization promoted afterwards and in face of increased demands during the Olympic Game, and was even developed into tourist souvenirs; and this tendency is still prevalent in these days. However, a new understanding of lacquerware among the government and the industry and changes in the market began after the 2000s, and a new policy for lacquerware started in the 2010s, and thus the diffusion of Korean lacquerware as everyday life goods in the contemporary Korean society is expected. This study intends to analyze the process of progress in Korean lacquerware and the trends of the government’s promotion policy and commercialization for Korean lacquerware, thereby investigating the probability of its diffusion as contemporary daily goods.

비정형데이터를 활용한 코로나-19 팬데믹 이후 화장품 소비트렌드에 관한 연구

서수연,이명주,최에스더 한국미용학회 2022 한국미용학회지 Vol.28 No.6

This study conducted unstructured big data analysis to confirm consumers' perception of cosmetics in the face of increasing non-face-toface consumption due to COVID-19 pandemic. To this end, keywords related to cosmetics were collected through portal sites such as Naver, Daum, and Google using the social network matrix program called Textom. The collection period was set from Jan 2020 to DEC 2021, and a total of 18,672 keywords were collected, and a total of 60 keywords were used for the study by refining unnecessary keywords. The results are as follows. First, performing frequency, TF-IDF analysis, important keywords such as skin, basic makeup, recommendation, use, and brand were presented. Next, semantic network analysis showed that degree centrality was skin, basic makeup, recommendation, use, and brand, closeness centrality was CHANEL, authentication, export, and customize, betweeness centrality was skin, use, brand, products, and basic makeup. Finally, CONCOR analysis resulted in a cluster of five groups: cosmetic attributes, ingredients, products, sales, and using cosmetics. These analysis results confirm consumer perceptions related to cosmetics, key components and sales channels for cosmetics In addition, it is judged that it will propose meaningful implications for establishing effective data presentation and marketing strategies for research related to demand for cosmetics after COVID-19 pandemic.