유한요소법을 이용한 크랭크 축의 진동 해석에 관한 연구

강승주,오택열,최명진 慶熙大學校 材料科學技術硏究所 1994 材料科學技術硏究論集 Vol.7 No.-

High speed engines with high powers are increasingly in demand and engines employ crankshafts. Accordingly, such problems as bending and torsional vibrations become the point at issue in crankshaft design. In this study, modelling techniques for dynamic analysis of a crankshaft system are presented to investigate crankshaft system vibrations. The crankshaft was idealized by structure containing beams and shells, front pulley and flywheel modelled by a set of lumped masses and moments of inertia, and journal bearing modelled by a set of springs and dampers. These modelling and solution were applied for the analysis of four cylinder in-line engine, with free-free boundary condition, and with oil film supported boundary condition. The calculated natural frequencies and mode shapes were compared with the experimental results, and coincided well.

GMAW Narrow Gap Welding을 활용한 전차 용접방법 개선에 관한 연구

강승주,손민구,김록한,정연호 한국산학기술학회 2022 한국산학기술학회논문지 Vol.23 No.5

This study aimed to apply the GMAW narrow gap welding (NGW) to the welding process of OOTank manufacturing. Generally, high-hardness armor steel is used in a tank to ensure the survival of the passengers in the tank. In addition, the weld groove angle for the plates used in the tank components manufacturing is set wide according to the welding joint design MIL-HDBK-21, so the welding volume increases as the plate thickness increases. However, high welding volumes cause poor welding qualities, such as increased brittleness and residual stresses of the welded part. Meanwhile, the NGW minimizes welding deformations by narrowing the weld groove angle of the parts being welded. Also, the NGW has already been used in industries to weld thick parts under different welding times. Therefore, this study applied the GMAW NGW to the welding process of OOTank manufacturing. In particular, this study confirmed and compared the soundness of the chosen X- and U-groove welded parts of the GMAW NGW, respectively, through a comparative test (involving microstructure analysis, tensile test, low-temperature impact test, etc., of the welded parts). The above confirmation and comparison showed that there was no significant difference between the X-, U-groove welded parts, and the NGW could be applied to the welding process of OOTank mass production. 이 연구의 주된 목적은 OO전차의 양산 용접공정에 GMAW Narrow Gap Welding을 활용한 용접방법 적용에 초점을 맞추었다. 전차와 같은 지상 전투차량의 경우 탑승인원의 생존을 보장하기 위해 균질압연장갑강이 사용되며, 용접 이음 설계 MIL-HDBK-21에 따라 용접부의 경사각이 넓게 정해져 있어 판재의 두께가 두꺼워 질수록 용접량이 증가한다. 증가한 용접량은 취성 및 잔류응력 증가 등 용접품질 저하의 원인이 되어 OO전차의 용접 시 용접량을 줄일 필요성이 제기되었다. 이를 해결하기 위한 방법으로 용접부 경사각을 좁혀 용접변형을 최소화하는 NGW가 있으며 원자력, 선박 설비 등 용접 두께가 두껍고 용접횟수가 많은 산업에서는 이미 적용 중에 있다. 하지만 현재까지 전차와 장갑차와 같은 지상전투 차량의 용접공정에서는 NGW가 적용된 사례는 없다. 따라서, 본 연구에서는 지상전투 차량 중 하나인 OO전차의 용접공정에 NGW 적용을 위한 연구를 수행하였다. NGW 용접 적용부의 건정성과 안정성을 확인하기 위해 기존 X-groove 용접부와 NGW를 적용한 U-groove 용접부의 비교시험(인성시험, 저온충격시험, 경도분포 시험, 미세조직분석, 피로시험 등)을 진행하였다. 그 결과 X, U-groove 용접부에 대한 기계/금속학적인 특성 평가 결과가 유사하고 기준을 만족함을 확인하여 OO전차 현업 용접공정에 NGW 적용하고자 한다.

간호대학생의 공감능력, 눈치, 학습몰입이 임상수행능력에 미치는 영향

강승주,심정신,Kang, Seung-Ju,Shim, Chung-sin 국제문화기술진흥원 2021 The Journal of the Convergence on Culture Technolo Vol.7 No.3

본 연구의 목적은 간호대학생의 공감능력, 눈치, 학습몰입과 임상수행능력간의 관계를 파악하고 임상수행능력에 영향을 미치는 요인을 파악하고자 시도되었다. 자료수집은 K광역시에 소재한 일 간호대학에 재학 중인 179명을 대상으로 연구기간은 2021년 5월 10일부터 5월 14일까지 구조화된 설문지를 이용하여 실시하였다. 자료분석은 SPSS WIN21을 이용하여 빈도, paired t-test, ANOVA, Pearson's correlation coefficients, 다중회귀분석을 이용하였다. 연구결과 간호대학생의 공감능력과 눈치는 유의한 순 상관관계를 보였으며(r=.148, p=.048), 임상수행능력은 학습몰입과 유의한 순 상관관계(r=.605, p<.001)가 있는 것으로 나타났다. 간호대학생의 임상수행능력에 영향을 미치는 요인은 학업성취도(𝛽=.129,p=.049), 연령(𝛽=-.116, p=.014), 실습만족도(𝛽=-.242, p<.001)순으로 나타났다. 또한 이들 변수의 임상수행능력에 대한 설명력(R²)은 39.4%이었다. 따라서 비대면 온라인 실습에 대한 간호대학생의 임상수행능력을 높이기 위해 학업성취도를 향상시킬 수 있는 구체적인 전략과 온라인 실습을 만족할 수 있도록 다양한 활동과 교육 프로그램 개발이 필요하다. The purpose of this study was to investigate empathic ability, Nunchi, learning flow and clinical competency, and to identify the influencing factors on clinical competency of nursing students. Method: There were 179 nursing students as participants in K city, who were surveyed between May 10 and May 14, 2021, using a self-report questionnaire. Data were analyzed by frequencies, t-test, ANOVA, Pearson's correlation, multiple regression using SPSS Win 21.0. Result: There was a positive correlation between empathic ability and Nunchi(r=.148, p=.048) and between learning flow and clinical competency(r=.605, p<.001). In the multiple regression, Academic achievement(𝛽=.129, p=.049), Age(𝛽=-.116, p=.014) and satisfaction of clinical practice(𝛽=-.242, p<.001) were associated with clinical competency. These factors accounted for 38.4% of the total variance in clinical competency. Therefore, to improve clinical competency of online nursing practice of nursing college students, it is necessary to develop a specific strategy to improve academic achievement and to develop various activities and programs to immerse students in satisfaction of online practice.

Clinical Practice Guideline for Gastritis in Korea

강승주,Kim Jae Gyu,Moon Hee Seok,Kook Myeong-Cherl,Lee Jong Yeul,방창석,태정현,공은정,남수연,Kim Hyun Jung 대한의학회 2023 Journal of Korean medical science Vol.38 No.13

Gastritis is a disease characterized by inflammation of the gastric mucosa. It is very common and has various classification systems such as the updated Sydney system. As there is a lot of evidence that Helicobacter pylori infection is associated with the development of gastric cancer and that gastric cancer can be prevented by eradication, H. pylori gastritis has been emphasized recently. The incidence rate of gastric cancer in Korea is the highest in the world, and due to the spread of screening endoscopy, atrophic gastritis and intestinal metaplasia are commonly diagnosed in the general population. However, there have been no clinical guidelines developed in Korea for these lesions. Therefore, this clinical guideline has been developed by the Korean College of Helicobacter and Upper Gastrointestinal Research for important topics that are frequently encountered in clinical situations related to gastritis. Evidence-based guidelines were developed through systematic review and de novo processes, and eight recommendations were made for eight key questions. This guideline needs to be periodically revised according to the needs of clinical practice or as important evidence about this issue is published in the future.

제주도산 홍조 아프리카바다표고(Peyssonnelia capensis Montagne)의 분류학적 특성

강승주,이재완,이욱재,오윤식,이해복,Kang, Seung-Ju,Lee, Jae-Wan,Lee, Wook-Jae,Oh, Yoon-Sik,Lee, Hae-Bok 한국조류학회(藻類) 2006 ALGAE Vol.21 No.2

The characteristics of Peyssonnelia capensis Montagne (Peyssonneliaceae, Rhodophyta) from Jeju Island were investigated in order to clarify the species entity and re-evaluate taxonomic position. The morphological variations of the Peyssonnelia capensis from Jeju Island were divided into two types, the thin thallus type and the thick thallus type. The thin thallus type is characterized by thin, soft, orbicular, slightly lobed thallus with entire to undulate margin, and compact rhizoids. The thick thallus type has thick and stiff thallus with sinuate margin and scattered rhizoids, and has more branches than the thin thallus type. The basal layer and the epithallium of thin thallus type are similar to those of thick thallus types in their structure. However, the hypothallial cells of the thick thallus type are longer than those of the thin thallus type. The erect filament of thick thallus type has more cells than those of the thin thallus type. Tetrasporangial nemathecia are distinctly protruded. Mature tetrasporangia of this species are divided cruciately into four spores as those of other Peyssonneliaceae. In addition to their morphological and anatomical distinctness between two types, the nucleotide sequence analyses of SSU and ITS2 region make no differences among populations from Jeju and other localities in Korea. Therefore these two morphological variation may not base on genetic variation.

의료용 나노스케일 혈액분석 시스템(N-BAS) 공정기술 개발

강승주 대한전기학회 2003 전기의 세계 Vol.52 No.6

中學生의 基督敎 價値敎育을 위한 相談模型 開發에 關한 硏究

姜承周 한국외국어대학교 교육대학원 1987 교육논총 Vol.2 No.1

수분산 공액고분자 나노입자의 합성 방법론

강승주,강보석 한국접착및계면학회 2023 접착 및 계면 Vol.24 No.1

A conjugated polymer is the next-generation emerging semiconductor material that can be applied in various fields, from organic electronics to biomedical applications. However, its low solubility in an aqueous medium has made the use of toxic organic solvents inevitable, thereby leading to formulation of conjugated polymers in the form of waterborne nanoparticles. This review paper discusses two principles of nanoparticle formation and representative methods for synthesizing conjugated polymer nanoparticles.

혈액 한 방울로 건강 상태를 알아낸다

강승주,Gang, Seung-Ju 한국과학기술단체총연합회 2005 과학과 기술 Vol.38 No.9

In situ 도핑 합성법을 이용한 고전도성 N형 공액 고분자

강승주,강보석 한국고분자학회 2023 고분자 과학과 기술 Vol.34 No.3