공군 훈련용 경항공기 엔진 정비작업 개선

김승준,원종서 대한산업공학회 2017 대한산업공학회 추계학술대회논문집 Vol.2017 No.11

Evaluation of the Structural Performance of Tetragonal Lattice Girders

김승준,한택희,백정식,강영종 한국강구조학회 2013 International Journal of Steel Structures Vol.13 No.1

This paper presents an evaluation of the structural performance of tetragonal lattice girders for NATM tunnel construction. H-shaped steel ribs and triangular lattice girders have been widely used as a temporary support for NATM tunneling. H steel ribs have high flexural stiffness and strength, but they may induce unexpected internal gaps after shotcreting, because of their geometric characteristics. To overcome the problem, triangular lattice girders were developed. However, the lattice girder revealed frequent local failure at the joints of each bar. Moreover, those two supports show the quite low connection strength of members. Recently, a new type support, the tetragonal lattice girder, was developed to overcome the weaknesses of former supports. In this study, the structural performance of the new type support was studied by analytical and experimental methods. For the evaluation, 4-point flexural analysis, the conventional evaluation method, and arch analysis including stability analysis were performed. In addition, a 4-point flexural experiment was performed to evaluate the ultimate load carrying capacity, and observe whether local failure occurs or not. In the experimental study, a connected model was also considered as well as a unit model, in order to check the rationality of the connection method of the girder. All analytical and experimental results were compared with the structural performance of former supports.

Structural Stability of Cable-stayed Bridges

김승준,원덕희,이기세,강영종 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.3

This paper presents an investigation of the structural stability of cable-stayed bridges based on nonlinear analysis. In general, girders and masts of cable-stayed bridges are always subjected to compressive forces due to pre-tensioned stay cables. Cablestayed bridges exhibit various geometric nonlinearities, such as the cable-sag effect, beam-column effect of girders and masts, and large displacement effect. In this study, the characteristics of the structural stability of cable-stayed bridges are investigated. Because of various geometric nonlinearities, nonlinear finite element analysis should be performed for stability analysis instead of conventional eigenvalue analysis. Furthermore, the initial shape analysis should be performed prior to live load analysis in order to consider the dead load condition rationally. A two-step analysis method, developed based on the theory of nonlinear finite element method, is presented in this study for stability analysis under live load cases. An intensive series of parametric studies is subsequently performed using three-span cable-stayed bridges. The main buckling modes are classified depending on the location of the critical members. Also, the effects of cable arrangement, girder-mast stiffness ratio, area, and the number of cables on the structural stability are extensively investigated.

강한 인장 상태에서의 계류 체인 링크의 휨 거동

김승준,원덕희 한국강구조학회 2017 韓國鋼構造學會 論文集 Vol.29 No.2

This paper presents the study of the bending behavior of mooring chain links for keeping the position of the offshore floating structures. In general, chain links have been thought as the axial members due to the fundamental boundary condition. But, the flexural stiffness can be induced to the contact surface between chain links when friction occurs at the surface of the chain links due to high tensile force. Especially, the mooring chains for offshore floating platforms are highly tensioned. If the floater suffers rotational motion and the mooring chain links are highly tensioned, the rotation between contact links, induced by the floater rotation, generates the bending moment and relevant stresses due to the unexpected bending stiffness. In 2005, the mooring chain links for the Girassol Buoy Platform were failed after just 5 months after facility installation, and the accident investigation research concluded the chain failure was mainly caused by the fatigue due to the unexpected bending stress fluctuation. This study investigates the pattern of the induced bending stiffness and stresses of the highly tensioned chain links by nonlinear finite element analysis. 본 연구는 부유식 구조물의 위치 제어를 위한 계류 체인 링크의 휨 거동에 대해 다룬다. 일반적으로 체인 구조는 링크 간 연결조건에 따라 축력만 전달하는 구조체로 인식되었다. 그러나 체인에 강한 인장력이 작용할 때, 접촉하는 두 링크 간의 마찰력에 의해 휨 강성이도입되게 된다. 특히, 부유식 플랫폼의 계류선은 강한 인장력이 유지되는데, 물리적으로는 긴장 상태에 있는 체인 링크 간 접촉면에 마찰특성에 의해 휨 강성이 도입되면 환경하중을 받는 플랫폼에 회전 운동이 발생할 때, 계류선에도 회전 변위를 일으키고 이는 결과적으로 설계시 고려하지 못한 휨모멘트 및 휨응력이 체인에 작용하게 된다. 실제 2005년 Girrasol Buoy 플랫폼의 해상 설치 후 5개월 만에 파손된계류 체인의 사고 조사 시 주요 원인으로 이러한 휨 거동에 의한 부가 피로손상 누적이 지적되었다. 본 연구에서는 비선형 유한요소해석을통해 긴장상태에 있는 체인에 도입되는 휨 강성 및 휨 응력의 특성에 대해 분석한다.

기관지천식환자의 기도재구성과 기관지폐포세척액 세포의 transforming growth factor-β1 및 basic fibroblast growth factor 발현과의 관계

김승준,이숙영,박용근,김명훈,김석찬,권순석,김영균,김관형,문화식,송정섭,박성학 대한천식알레르기학회 2002 천식 및 알레르기 Vol.22 No.4

A Study On Maritime Province Government In The Transitional Period: Analysis And Other Factors Of Establishment Process

김승준 21세기정치학회 2011 21세기 정치학회보 Vol.21 No.2

This writing developed the hypothesis by the neoinstitutional view as the theoretical frame and its background to study the establishment process of the provincial self government of Maritime province in the transition period. And studied the several factors of the establishment process of the provincial self government in Maritime province in the transitional period while studying the course of the formation of the administration and the legislature in Maritime province under the framework of the view of the neoinstitutional analysis. The results of the study on the elements of the behaviors done by the neoinstitutional analysis proves that Maritime province is entered into the non-political low level of the institutionalization This writing developed the hypothesis by the neoinstitutional view as the theoretical frame and its background to study the establishment process of the provincial self government of Maritime province in the transition period. And studied the several factors of the establishment process of the provincial self government in Maritime province in the transitional period while studying the course of the formation of the administration and the legislature in Maritime province under the framework of the view of the neoinstitutional analysis. The results of the study on the elements of the behaviors done by the neoinstitutional analysis proves that Maritime province is entered into the non-political low level of the institutionalization

Laboratory of Structural Biology

김승준 생화학분자생물학회(구 한국생화학분자생물학회) 2012 생화학분자생물학회 소식 Vol.32 No.4

도시철도 수요검증 및 버스 노선 조정 방안 - 우이신설선 사례를 통해 -

김승준,김영범 한국ITS학회 2018 한국ITS학회 학술대회 Vol.2018 No.04

[특집 : 철도안전] 개별요소법(Discrete Element Method)을 활용한 자갈궤도 자갈층 모델링 기법

김승준 한국방재학회 2021 한국방재학회지 Vol.21 No.4

'스콜라' 이용 시 소속기관이 구독 중이 아닌 경우, 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

양극성 조증 환자에서 언어, 얼굴, 장면 감정자극에 대한 정서 일치 편향:정상인 및 정신분열병 환자와의 비교

김승준,강지인,이지현,안석균,조현상 대한정신약물학회 2009 대한정신약물학회지 Vol.20 No.3

Objective:Patients with bipolar mania have difficulty in recognizing or attending to negatively affective stimuli and have an affective bias, which is congruent with the current mood. However, previous reports have adopted words or facial pictures, not scenic pictures as affective stimuli. In this study, patients with mania performed the word, face and scenic picture-based affective go-nogo tasks respectively. The results were compared to those of patients with schizophrenia and healthy controls. Methods:Twenty patients with bipolar mania, 20 patients with schizophrenia, and 20 healthy comparison subjects, matched for age, gender and intelligence, performed affective gonogo tasks which contained happy/sad words, facial pictures, and scenic pictures respectively. Results:On the scenic picturebased affective go-nogo task, a significant interaction between subject group and target valence emerged {F (2,57)=4.86, p<0.05}. Pairwise comparison showed the manic patients required significantly more time to respond to sad than to happy stimuli (t=3.22, df=19, p<0.01), but schizophrenia patents and healthy subjects did not differ in time to respond to happy or sad stimuli (t=1.95, df=19, p=0.07;t=-1.23, df=19, p=0.23). Conclusion:Manic patients displayed a mood-congruent bias toward affective scenic pictures, but not toward affective word or facial pictures. This finding suggests that complex and scenic stimuli may give a more influence on the affective arousal state and therefore increase the mood-congruent bias in manic patients. 양극성 조증 환자들은 부정적인 감정 자극에 대한 주의력 혹은 인식 능력이 감소되어 결과적으로 긍정적인 감정 자극에 대한 정서 일치 편향을 보이는 것으로 알려져 있다. 그러나 기존의 연구들은 주로 단어 혹은 얼굴 사진을 감정 자극으로 사용하였으며 장면 사진을 사용한 예는 없는 상황이다. 본 연구에서는 단어, 얼굴 사진뿐만 아니라 장면 사진을 사용한 정서 go-nogo 검사를 통해 각기 다른 정서 자극들에서 양극성 조증 환자들과 정신분열병 환자, 정상인의 정서 편향 여부를 조사하였다. 성별, 나이, 지능을 고려하여 모집한 20명의 양극성 조증 환자들, 20명의 정신분열병 환자들, 20명의정상인을 대상으로 두 개의 정서가(행복/슬픔와 세 개의 자극 종류(단어, 얼굴 사진 및 장면 사진)를 이용한 정서 go-nogo 검사를 시행하였다. 장면 사진을 이용한 정서 go-nogo 검사 결과 중 반응 시간에서 세 군과 두 자극 감정가 간의 유의미한 상호작용이 관찰되었다. 대응 표본 t 검정에 따르면 양극성 조증 환자군에서는 행복한 자극보다 슬픈 자극에 대한 반응 시간이 증가하는 것으로 나타났으나, 정신분열병 환자군과 정상군에서는 자극 감정가 간의 유의미한 차이가 관찰되지 않았다. 결론적으로 양극성 조증 환자에서 장면 정서사진을 이용한 정서 go-nogo 검사를 시행했을 때 행복 자극보다 슬픔 자극에 대한 반응 시간이 연장되어 있는 바 이는 양극성 조증의 정서 일치 편향의 특성을 보여준다. 이러한 결과는 복잡한 장면 사진이 양극성 조증 환자에게서 더욱 큰 정서 각성 상태를 유발하여 정서 일치 편향을 증가시킬 수 있음을 시사한다.