http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
타워크레인 텔레스코핑 작업의 풍속 및 하중에 대한 구조 안전성 연구
정성룡,이도근,백신원,신상연,Jung, Sung-Lyoung,Lee, Do-Geun,Paik, Shinwon,Shin, Sang-Yeon 한국안전학회 2021 한국안전학회지 Vol.36 No.1
This study analyses the load imbalance of the tower crane used in telescoping work for structural safety, owing to the difference in wind speed and balance weight position. This is because wind speed and position of the balance weight have a significant impact on the structural stresses of a tower crane during telescoping work. Therefore, structural analysis was performed on the 290HC model, which is often used at construction sites and has only one cylinder installed. Moreover, two models were classified to determine the load acting on the connecting part of the telescopic cage to slewing platform and the cylinder. Five types of balance weight positions were applied at regular intervals from jibs; moreover, four types of wind load criteria were differently applied. Hence, the telescopic cage columns were destroyed at all balance weight positions at a wind speed of 30 m/s and only at certain locations at a wind speed of 20 m/s. Furthermore, failures occurred for cylinders, torsional, and bending at wind speeds of 30 m/s and 20 m/s, load imbalances above the allowable thresholds considering the safety factor. In addition, the load imbalance in the telescoping work also varied depending on the position of the balance weights. The results of these studies have validated that the current standards of adjusting the appropriate position of the balance weights on the jib are completely valid, with the telescoping work to be executed only at wind speeds of less than equal to 10 m/s.
정성룡(S.R. Chung),이근상(K.S. Lee),최병하(B.H. Choi),최종근(J.K. Choi) 한국자동차공학회 1996 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1996 No.6_1
There has long been a need for an. accurate prediction of the wear rate and wear distribution of tire tread. Techniques proposed so far have a limited applicability because they are expensive and time-consuming or too qualitative.<br/> This study presents an improved paint wear test. This method permits the wear rate to be quantitatively evaluated after a greatly reduced mileage. The resolution possible with point-to-point measurement allows wear within complex tread element block to be measured more accurately than by previous methods. Also, it is possible to control test conditions and minimize effects of unwanted factors. A typical example is provided to show wear distribution across shoulder to shoulder of truck tire.<br/>
분산 환경에서 객체 관계 데이터베이스 시스템을 이용한 XML 문서 관리 시스템의 구현 및 성능 평가
정성룡 ( Seong Ryoung Jeong ),홍의경 ( Eui Kyeong Hong ) 서울시립대학교 산업기술연구소 2006 산업기술연구소논문집 Vol.14 No.-
Data exchange among heterogenous database that is not matched data model each other is gathering strength as ubiquitous research is in progress. XML document is so compatible with data that it is appropriate for data exchange in ubiquitous environment. According to database-system`s advantage, the research that stores XML document in object oriented database is progressed. There are several methods that are storing and quering XML document in object relational database system. They are different from practical application. In this research, we are going to design and develop middleware that manage XML using object relational database system in distributed environment. And then, we are going to evaluate performance that is storing and quering XML document in this system.
정성룡(Sung-Ryong Chung) 한국자동차공학회 1998 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1998 No.5_2
In this study. as an efficient method for measuring the frictional energy on the contact patch of an automobile tires, paint wear method is described. It comprises applying a single layer of paint to tread surface by spraying, running the tires on a vehicle for a short distance, assessing the wear rate by measuring the intensities of reflecting lights at various locations, and comparing them with original values. This method permits the wear rate to be quantitatively evaluated with a very high resolution under well-controlled test conditions.<br/> A typical example is provided to show wear distribution across shoulder to shoulder of passenger car tires. Tread wear patterns produced by different toe-in angle have been analyzed through the range of tread wear patterns. Application of this method makes studies of the effects of wheel alignment and tire on uneven wear possible.<br/>
정성룡(S.R.Chung),조규종(K.J.Cho) 한국자동차공학회 1993 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
In this study, the selection guide of tire intlation pressure are proposed to improve ride and handling quality. At the steady running state. the standard of the intation pressure is determined<br/> to fit the ride. handling and stahility, wear. and fuel consumsion performance etc. Based on the tire cornering theory, the effect of int1ation pressure on tire force and moment characteristics affecting on vehicle handling manuver was compared experimental results to theoretical analysis. The items for tire testing were the spring rate, footprint. and force and moment test. ADAMS code. which has been widely applied to the vehicle dynamics. has been used to simulate the vehicle / tire manuver according to the int1ation pressure. It is very helpful for the drivers to improve the ride and handling by controlling tire int1ation pressure properly. and for the chassis / tire engineers to optimize the design factors related to int1ation pressure.<br/>