中小企業의 業務전산화의 當爲性 및 企業電算化 導入의 問題點

권영봉 경상대학교 경영행정대학원 1990 最高管理者課程論文集 Vol.1 No.-

경량형강 지붕트러스 앵커부의 거동

권영봉,강승원,정현석,최영현,Kwon, Young Bong,Kang, Sueng Won,Chung, Hyun Suk,Choi, Young Hyun 한국강구조학회 2003 韓國鋼構造學會 論文集 Vol.15 No.5

최근에 스틸하우스나 고층아파트 지붕에 경량형강 지붕트러스의 사용이 증가하는 추세이다. 그러나 현재 지붕트러스와 하부구조의 앵커 접합부의 설계는 거의 경험에 의존하는 실정이다. 본 논문에서는 냉간성형형강 지붕트러스 앵커 접합부의 구조적인 거동에 관한 실험적인 연구를 서술하였다. 트러스부재와 접합철물은 스크류로 접합하였으며, 하부구조의 구조재료에 따라 시공성 및 구조적인 성능이 우수한 단순한 형태의 접합철물을 사용하여 철근콘크리트구조인 경우 케미컬 앵커볼트 그리고 강구조인 경우는 용접 및 DX-Pin을 사용하여 하부구조와 연결하였다. 다양한 접합부 형태에 대한 인발실험을 수향하여 접합부의 강도 및 강성을 측정하였으며, 이를 AISI시방서(1996) AISC시방서(1989)규정에 근거한 설계강도와 비교하였다. 또한 스크류 연결부의 최대전단강도식을 제안하여 실험결과와 비교하였다. In recent years, the use of cold-formed steel roof truss has been increased in the steel houses and high-rise apartments. The design of the roof truss anchor connections has been based on the experience and decision of designers. In this paper, the structural behavior of anchor connections based on experimental and decision is described. In the tests, truss members and connection members were jointed directly with self-drilling screw fasteners and the simple shaped connection member with excellent workability and structural capacity was used to connect roof truss and sub-structure. The connecting method was selected according to the construction material of sub-structure: chemical anchor for reinforced concrete structure and welding or DX-Pin for steel structures. The pull-out tests of various type anchor connection were executed to obtain the strength and the stiffness and the result have been compared with AISI(1996) and AlSC(1989) specifications, Simple formulas for the shear strength of screw connections have been propose and compared with tests.

박판 냉간성형형강 골조의 접합부 거동에 관한 실험적 연구

권영봉,조종수,송준엽,김갑득,Kwon, Young Bong,Cho, Jong Su,Song, Jun Yeup,Kim, Gap Deuk 한국강구조학회 2003 韓國鋼構造學會 論文集 Vol.15 No.3

신형상 폐단면 냉간성형형강 스터드와 래프터로 구성된 포탈프레임의 접합부의 모멘트-회전각 관계, 회전강성, 항복모멘트 및 극한모멘트 등을 파악하기 위하여 접합부실험을 수행하였다. 실험의 주요 변수는 연강 접합철물의 두께 및 형상과 접합부 시험체의 비틀림에 관한 구속조건이며, 실험결과의 검증을 위해서 비선형해석 결과와 비교하였다. 반강접 접합부의 휨강성을 실험에 의한 모멘트-회전각 곡선으로 부터 구한 할선강도로 제안하여 구조해석을 통하여 타당성을 검토하였다. A series of connection tests of portal frames which were composed of cold-formed steel studs and rafters was carried out to study the moment-rotation relation, the rotational rigidity, and the yield and the ultimate moment of the connections. The main factors of the tests were the thickness, the shape of the connecting members which were made of mild steel, and the torsional restraints of the test specimens. The test results were compared with those obtained through the non-linear analysis, for verification. The secant stiffness estimated from the experimental moment-rotation curve was proposed for the rotational rigidity of semi-rigid connections, and its validity was verified in the structural frame analysis.

경량형강 스터드 벽체의 휨강도에 관한 연구

권영봉,정현석,김갑득,Kwon, Young Bong,Chung, Hyun Seok,Kim, Gap Deuk 한국강구조학회 2003 韓國鋼構造學會 論文集 Vol.15 No.2

벽체용 박판냉간성형 Lip-C-형강의 구조적인 거동에 관한 연구의 일환으로 횡하중을 받는 스터드 벽체의 휨강도에 관한 실험적인 연구가 수행되었다. 시험체는 3개 또는 4개의 Lip-C-형강 스터드 부재의 양단을 C-형강 트랙으로 고정하여 제작되었다. 실험의 주요 변수는 스터드 복부의 천공 여부, 보강채널(bridge channel)의 간격 및 개수 그리고 보강 채널의 고정 및 스터드 플랜지의 간격 유지용 특수 클립(Clip)의 개수 등이며, 스터드의 인장측 플랜지에 부착된 합판과 석고보드의 벽에 강도에 미치는 영향이 연구되었다. 실험에 의한 휨강도는 AISI시방서(1996)에 근거한 강도와 비교하였다. An investigation on the structural behavior of cold-formed steel lipped C-section stud for interior walls or partitions was carried out. This experimental research was carried out to study the ultimate and service load capacity of stud assemblies that are subjected to lateral loads. Each test specimen consisted of three or four lipped C-section studs and two C-section tracks that restrained both ends. The major factors considered in this experiment were the perforation on the web, the connection of the bridge channel and the special clip. The effect of the plaster board and the ply wood, which were attached to the tension flange on the flexural strength, was also investigated. Thereafter, the test strength capacities were compared with the nominal strength, based on the AISI Specifications (1996).

The Structural Behavior of Anchor Connections for the Cold-Formed Steel Roof Truss

권영봉,Seung-Won Kang,Young-Hyun Choi 한국강구조학회 2005 International Journal of Steel Structures Vol.5 No.2

The great Hanshin Earthquake on January 17, 195 caused serious damage to various civil structures never beforereviewed in this paper.

에스자 대장암 및 직장암 환자에서 수술 전 후의 유입정맥 CEA (Carcinoembryonic antigen) 값의 변화 (개복수술과 복강경수술의 비교)

권영봉,최규석,박수연,전수한,박준석,장유석,장유석,김혜진 대한내시경복강경외과학회 2010 Journal of Minimally Invasive Surgery Vol.13 No.2

Purpose: Although the overall survival and recurrence rates after open or laparoscopic surgery for colorectal cancer are similar, the potential oncological benefits of laparoscopic surgery have not been established. This study compared the effects of the two surgical approaches (open and laparoscopic)on the intraoperative inferior mesenteric vein (IMV) carcinoembryonic antigen (CEA) levels in patients who were undergoing open or laparoscopic surgery for sigmoid colon and rectal cancer. Methods: Between December 2005 and July 2008, a total of 37 patients were enrolled in this study. Twenty one patients underwent open surgery and 16 patients were operated on laparoscopically. The baseline peripheral CEA level was measured preoperatively. The IMV blood was taken before and after mobilization of the cancer-bearing bowel segment and the CEA levels in the two groups were compared. Results: The baseline CEA levels in the peripheral vein were similar in the two groups. After mobilization, the overall CEA level was elevated. The median pre-mobilization CEA levels of the open and laparoscopic group were 2.3 (range: 1.2∼3.7)ng/ml and 1.5 (range: 1.0∼2.6) ng/ml, respectively. Hence,the degree of CEA elevation after mobilization was significantly higher in the open surgery group compared with that of the laparoscopic approach (4.2 vs. 1.6, respectively, p=0.004). Conclusion: The CEA levels measured from the IMV after mobilization were elevated to a lesser degree after laparoscopic mobilization of the cancer-bearing bowel segment, as compared with that of open surgery. However, the long term oncological effects need to be examined by conducting longer,larger scale studies.

복부에 슬릿이 있는 박판냉간성형형강 스터드의 압축강도

권영봉,서응규,임덕만,김갑득,권인규,Kwon, Young-Bong,Soe, Eung-Kyu,Lim, Duk-Man,Kim, Gap-Deuk,Kwon, In-Kyu 한국강구조학회 2012 韓國鋼構造學會 論文集 Vol.24 No.2

벽식 스틸하우스 벽체의 구조재로 적용되어 오고 있는 박판냉간성형형강 스터드의 경우 열교현상에 의한 단열상의 문제를 가지고 있기 때문에 추가적인 단열재의 사용이 요구된다. 이러한 단열 문제를 해결하기 위하여 웨브에 슬릿이 배치된 냉간성형강 단열스터드가 개발되었다. 그러나 슬릿의 배치로 인하여 단면강도 산정은 대단히 어려운 문제점이 되고 있다. 본 논문에는 단열스터드의 압축강도 및 구조적인 거동에 대한 실험 및 해석적인 연구결과를 기술하였다. 슬릿의 길이, 간격 및 배열형태를 달리하는 세 종류의 단열스터드에 대한 압축실험을 단면의 파괴 시까지 수행하였으며, 실험 및 해석결과에 근거하여 복부에 슬릿이 있는 냉간성형강 스터드에 적용하기 위한 단순한 형태의 강도 산정방법을 제안하였다. 제안된 강도산정법에서는 단열스터드를 등가두께의 슬릿이 없는 일반스터드로 대치하고, 이 등가단면에 직접강도법을 적용하여 단열스터드의 공칭압축강도를 산출한다. 제안된 강도산정방법은 단열스터드 실험결과와 비교하여 검증하였다. The cold-formed steel stud, which has been used as a load-bearing member of wall panels for steel houses, poses a significant problem in insulation due to heat bridging of the web. Therefore, some additional thermal insulating materials are required. In order to solve this problem, the cold-formed steel thermal stud with slits in the web was developed. However, estimating the structural strength of thermal studs is very difficult because of the arrangement of perforations. In this paper, an analytical and experimental research on thermal studs is described. Three types of studs with different length, pitch and arrangement of slits were tested to failure. A simple design approach was proposed based on the test results. The proposed method adopted the direct strength method, based on the elastic local and distortional buckling stress of plain studs with equivalent thickness in the web instead of thermal studs. The predictions using the proposed method were compared with test results for verification and the adequacy of the proposed method was confirmed.

평판구조물의 좌굴거동 추적을 위한 새로운 해석방법의 개발

권영봉 嶺南大學校 工業技術硏究所 1995 工業技術硏究所論文集 Vol.23 No.1

본 연구의 목적은 박판구조물의 좌굴 및 후좌굴의 거동을 추적하기 위한 비선형유한대판법 프로그램의 개발에 있으며 형상함수로는 판요소의 횡방향은 다항식을 종방향으로는 종형함수를 사용하였다. 전통적인 선형좌굴해석에서는 고려할 수 없는 기하학적인 초기부정형과 잔류응력 및 이의 영향으로 좌굴을 일으키기 전에 발생되는 휨변형을 고려할 수 있는 비선형좌굴 해석기법으로서 계산능률 및 정확도를 향상시키기 위하여 대수 및 수치적분을 혼합하여 사용하였으며 기존의 유한대판법과는 달리 다양한 단부구속조건 및 하중에 제한없이 적용이 가능하다. 초기부정형을 가진 평판과 평판요소로 구성된 박판단면에 적용하여 기존의 결과들과 비교하여 적용가능성을 평가하고 좌굴의 초기부정형에 대한 민감도를 연구하였다. The purpose of this paper is to provide and verify an analytical method, based on the spline finite strip method, which can be used to investigate the buckling mode and stress of thin-walled structures. Geometric imperfection and initial stress of plate and plate assemblies, which are resulted from various preloadings and may cause prebuckling deformations before buckling, are included in the analysis, Both numerical and algebraic integrations have been performed for matrix computations to improve the versatility so that the stress field originated from the initial and prebuckling deformations can be included. It can be applied to sections with simple or non-simple boundary conditions and subjected to arbitrary loading. The method has been applied to investigate the buckling behavior of plates and plate assemblies subjected to compression with initial imperfections and residual stresses. The sensitivity of the buckling behavior to the initial deformations are also studied.

콘크리트충전 강합성교각의 구조적 거동에 관한 연구

권영봉,신영식,권혁문 圓光大學校 環境建設硏究所 2000 環境建設論文集 Vol.9 No.-

The concrete-filled composite column can be adopted to assure mainly large energy-absorption capacity and enhancement of strength and stiffness due to mutual confinement between the steel plate and filled-in concrete when it is used as bridge piers. Moreover, the use of partially concrete-filled composite piers offer reduction of the weight of the pier itself and reducing construction time. In this study, a set of tests has been conducted on long columns subjected to constant axial load and cyclic lateral load. The width-thickness ratio, slenderness ratio, filled-in concrete length and lateral load history were taken as main test parameters. The optimum filled-in concrete length has been proposed. Ductility index estimated for the seismic design showed that the composite piers could be used as a very efficient earthquake-resistant structural member.

Compression tests of cold-formed channel sections with perforations in the web

권영봉,김갑득,권인규 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.16 No.6

This paper describes a series of compression tests performed on cold-formed steel channel sections with perforations in the web (thermal studs) fabricated from a galvanized steel plate whose thickness ranged from 1.0 mm to 1.6 mm and nominal yield stress was 295 MPa. The structural behavior and performance of thermal studs undergoing local, distortional, or flexural-torsional buckling were investigated experimentally and analytically. The compression tests indicate that the slits in the web had significant negative effects on the buckling and ultimate strength of thin-walled channel section columns. The compressive strength of perforated thermal studs was estimated using equivalent solid channel sections of reduced thickness instead of the studs. The direct strength method, a newly developed and adopted alternative to the effective width method for designing cold-formed steel sections in the AISI Standard S100 (2004) and AS/NZS 4600 (Standard Australia 2005), was calibrated to the test results for its application to cold-formed channel sections with slits in the web. The results verify that the DSM can predict the ultimate strength of channel section columns with slits in the web by substituting equivalent solid sections of reduced thickness for them.