병원 표준화 심사 : 약제부문

이병구 한국병원약사회 2001 병원약사회지 Vol.18 No.2

칼슘길항제

이병구 약업신문사 2000 의약정보 Vol.2000 No.7

Minimum-weight Beams with Shear Strain Energy

이병구,오상진,이태은,박정수 대한토목학회 2012 KSCE Journal of Civil Engineering Vol.16 No.1

This paper deals with minimum-weight beams built with the minimum volume of beam material that can sustain the subjected load. In order to build a minimum-weight beam, the geometry of the strongest beam is analyzed, for which the values of the maximum beam behaviors are minimized at the given volume of material. For the structural analysis of such a beam, the theorem of least work is employed, considering strain energies of both bending and shear. Further, deflection curves are obtained using the successive integration method. The strongest section ratios, as determined by both the maxi-mini stress and deflection, are obtained from the results of the structural analysis. The beam geometry of the minimum-weight beam, which is described by the taper type,side number, volume, and cross sectional depth, is determined from the given allowable stress and deflection. In numerical examples,three kinds of end constraint are considered: hinged-hinged, hinged-clamped, and clamped-clamped beams.

뿌리업종 중견중소기업의 설비 AI 플랫폼 구축에 관한 사례연구

이병구,문태수 한국정보시스템학회 2023 情報시스템硏究 Vol.32 No.3

Purpose This study investigates the impact of organizational characteristics on organizational performance through case studies of smart factory implementation in the context of Korean small and medium Enterprises (SMEs). To achieve this goal, this study adopts the smart factory index of KOSMO (Korea Smart Manufacturing Office) established by Korean Ministry of SMEs and Startups. We visited 3 firms implemented smart factory projects. This study presents the results of field study in detail with evaluation criteria on how organizational competences like AI technology adoption and facility automation can be exploited to positively influence organizational performance through smart factory implementation. Design/methodology/approach There are not so many results of empirical studies related to smart factories in Korea. This is because organizational support and user involvement are required for facility AI platform service beyond factory automation after the start of the 4th Industrial Revolution. Korean government's KOSMO (Korean Smart Manufacturing Office) has developed and proposed a level measurement index for smart factory implementation. This study conducts case studies based on the level measurement method proposed by KOSMO in the process of conducting case studies of three companies belonging to the root and mechanic industries in Korea. Findings The findings indicate that organizational competences, such as facility AI platform adoption and user involvement, are antecedents to influence smart factory implementation, while smart factory implementation has significant relationship with organizational performance. This study provides a better understanding of the connection between organizational competences and organizational performance through smart factory case studies. This study suggests that SMEs should focus on enhancing their organizational competences for improving organizational performance through implementing smart factory projects.

Planar Free Vibrations of Horseshoe Elliptic Arch

이병구,박광규,오상진,이태은 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.4

This paper deals with planar free vibrations of the horseshoe elliptic uniform arch. Simultaneous differential equations governing free vibrations of such arch are derived, in which the axial extensional deformation is included and the radial and tangential deformations are normalized by the intercept of the horizontal axis. The differential equations are numerically solved for calculating natural frequencies with their corresponding mode shapes. In parametric studies, effects of the rotatory inertia, aspect ratio, subtended angle and slenderness ratio on frequency parameters are extensively discussed. Typical mode shapes of the radial and tangential deformations are presented in figures.

Numerical Methods for Determining Strongest Cantilever Beam with Constant Volume

이병구,이태은,정유성 대한토목학회 2012 KSCE JOURNAL OF CIVIL ENGINEERING Vol.16 No.1

This paper deals with the development of numerical methods for determining the strongest cantilever beam having a constant volume of the beam material. An analytical method for calculating the properties of the cross section shaped as a solid regular polygon is formulated. For carrying out structural analyses of the cantilever beam, the stress resultants are computed and the differential equation of the elastic curve is derived, in which the effect of shear deformation as well as bending moment is included. The optimal geometries of the strongest beam are determined from the results of the structural analysis. Extreme stress and deflection are chosen as the decision criteria for determining the strongest beam. By using the geometries of the strongest beam obtained in this study, a design example of the minimum weight beam, which can sustain the subjected load with the minimum volume of the beam material, is presented. This paper deals with the development of numerical methods for determining the strongest cantilever beam having a constant volume of the beam material. An analytical method for calculating the properties of the cross section shaped as a solid regular polygon is formulated. For carrying out structural analyses of the cantilever beam, the stress resultants are computed and the differential equation of the elastic curve is derived, in which the effect of shear deformation as well as bending moment is included. The optimal geometries of the strongest beam are determined from the results of the structural analysis. Extreme stress and deflection are chosen as the decision criteria for determining the strongest beam. By using the geometries of the strongest beam obtained in this study, a design example of the minimum weight beam, which can sustain the subjected load with the minimum volume of the beam material, is presented.

미국의 INF 조약 탈퇴 선언과 동아시아 안보의 미래

이병구 국방대학교 국가안전보장문제연구소 2019 국방연구 Vol.62 No.2

The U.S. decision to withdraw from the INF reflects the concerns of Russia’s violation of the INF treaty and the increasing missiles threats from China, which is not a signatory of the treaty. The INF treaty, which was the most important success in the history of arms control and a symbol of the breakdown of the Cold War, is in the process of dismantlement. It is likely that the future will be characterized by the intensifying competition among great powers, leading to instability in global security. The abolition of the INF treaty poses three significant implications for the Asian security. First, a conventional arms competition in missiles and missile defense is very likely. Second, it is likely that the momentum for international nuclear arms control will get lost and the concerns for vertical nuclear proliferation and limited nuclear war will increase. Third, the negotiation over the denuclearization of North Kroea will be faced with hurdles. 미국의 INF 탈퇴 선언은 러시아의 INF 조약 위반 그리고 INF 조약의 대상국이 아닌 중국으로부터의 지속적 미사일 위협 증가에 대한 우려를 반영하고 있다. 군비통제 역사상 가장 중요한 성과이자 제2차 세계대전 이후 국제안보의 핵심 구조였던 동서 냉전 체제의 해체를 견인하는 중대한 진전이었던 INF 조약이 체결 30여 년 만에 폐기의 수순을 밟고 있다. 향후 강대국 경쟁의 심화를 중심으로 한 국제안보의 불안정성이 점증할 가능성이 높다. INF 조약의 폐기는 다음의 세 가지 측면에서 동아시아 안보에 중대한 함의를 지닌다. 첫째, INF 조약의 폐기 이후 미사일과 미사일방어를 중심으로 한 재래식 군비경쟁이 본격화하 것이다. 둘째, INF 조약의 폐기는 국제 핵군비통제 모멘텀의 상실과 수직적 핵확산 및 제한핵전쟁에 대한 우려 증가로 이어질 가능성이 높다. 셋째, 북한 비핵화 협상에 대한 도전요소가 증가할 가능성이 높다.

마제형 원호 아치의 면내 자유진동

이병구,오상진,이태은,Lee, Byoung Koo,Oh, Sang Jin,Lee, Tae Eun 대한토목학회 2014 대한토목학회논문집 Vol.34 No.4

이 연구는 마제형 원호 아치의 면내 저유진동에 관한 연구이다. 마제형 아치의 면내 자유진동을 지배하는 연립 상미분방정식을 곡률중심 및 접선 방향의 변위에 대하여 유도하였다. 특히 지배미분방정식은 반원보다 큰 중심각을 갖는 마제형 아치에 적용하기 위하여 각좌표보다는 곡선거리 좌표에 관한 미분방정식으로 유도하였다. 미분방정식을 수치해석하여 고유진동수와 진동형을 산출하였다. 변수연구를 통하여 회전관성, 세장비, 곡선길이비가 무차원 고유진동수에 미치는 영향을 분석하였다. This paper deals with in-plane free vibrations of the horseshoe circular arch. Simultaneous ordinary differential equations governing free vibration of the arch are derived with respect to the radial and tangential deformations. Particularly, differential equations are obtained under the arc length coordinate rather than the angular one in order to extend the horseshoe arch whose subtended angle is greater than ${\pi}$ radians. The differential equations are numerically solved for calculating the natural frequencies accompanying with the corresponding mode shapes. In parametric studies, effects of the rotatory inertia, slenderness ratio and circumferential arc length ratio on frequency parameters are extensively discussed.

두 변수 탄성지반으로 지지된 불연속 변단면 수평 곡선부재의 자유진동

이병구,이태은,안대순,김무영,Lee, Byoung Koo,Lee, Tae Eun,Ahn, Dae Soon,Kim, Mu Young 한국강구조학회 2001 韓國鋼構造學會 論文集 Vol.13 No.6

이 논문은 두 변수 탄성지반 위에 놓인 불연속 변단면 수평 곡선부재의 자유 진동에 관한 연구이다. 회전관성과 전단변형효과를 고려하여 두 변수 탄성지반 위에 놓인 변단면 수평 곡선부재의 자유진동을 지배하는 무차원 상미분방정식을 유도하였다. 변단면은 불연속 변단면으로 채택하였고, 회전-회전, 회전-고정 및 고정-고정의 단부조건을 갖는 원호형, 포물선형, 정현형, 타원형 곡선보의 고유진동수를 산출하였다. 수치해석의 결과로 무차원 고유진동수와 곡선부재의 변수들 사이의 관계를 표 및 그림에 나타내었으며 진동형의 예를 그림과 같이 나타내었다. The main purpose of this paper is to present an analytical method for free vibration of stepped horizontally curved members on two-parameter elastic foundation. The ordinary differential equations governing the free vibration of such beams are derived as non-dimensional forms including the effects of rotatory inertia and shear deformation. The governing equations are solved numerically for the circular, parabolic, sinusoidal and elliptic curved beams with hinged-hinged, hinged-clamped and clamped-clamped end constraints. As the numerical results, the lowest four natural frequency parameters are presented as the functions of various non-dimensional system parameters. Also the typical mode shapes are presented.

일정체적 원형 변단면 보-기둥의 자유진동 및 좌굴하중

이병구 한국전산구조공학회 1996 한국전산구조공학회논문집 Vol.9 No.3

일정체적의 원형단면을 갖는 변단면 보-기둥의 자유진동 및 좌굴하중을 지배하는 미분방정식을 유도하고 이를 수치해석하였다. 미분방정식에는 축하중효과를 고려하였다. 원형단면의 반경변화는 포물선식을 채택하였고, 고정-고정, 고정-회전 및 회전-회전 보-기둥의 고유진동수 및 좌굴하중을 산출하였다. 수치해석의 결과로 무차원 고유진동수와 무차원 변수들 사이의 관계 및 무차원 좌굴하중과 단면비 사이의 관계를 그림에 나타내었고, 최강기둥의 단면비와 좌굴하중을 구하였다. The differential equations governing both the free vibrations and buckling loads of tapered beam-columns of circular cross-section with constant volume are derived and solved numerically. The effects of axial load are included in the differential equations. The parabolic equation is chosen as the variable radius of circular cross-section for the tapered beam-column. In numerical examples, the clamped-clamped, clamped-hinged and hinged-hinged end constraints are considered. The variations of the frequency parameters and buckling load parameters with the non-dimensional system parameters are presented in figures and the configurations of strongest columns are obtained.