An inevitable consequence of the development of the offshore petroleum industry is the eventual obsolescence of large offshore structures. Proper methods for removal of decommissioned offshore platforms are becoming a...An inevitable consequence of the development of the offshore petroleum industry is the eventual obsolescence of large offshore structures. Proper methods for removal of decommissioned offshore platforms are becoming an important topic that the oil and gas industry must pay increasing attention to. While removing sections from a decommissioned jacket platform, the stability of the remaining parts is critical The jacket danger indices D ~ and Ds defined in this paper are very useful for analyzing the safety of any procedure planned for disassembling a jacket platform. The safest piles cutting sequence can be determined easily by comparing every column of Do and Ds or simply analyzing the figures of every row ofD o and D,.展开更多
This study aims to analyze the quality of positioning orthophoto generated through the technique of direct georeferencing using metric digital camera system coupled to the laser system, and both systems were aided ine...This study aims to analyze the quality of positioning orthophoto generated through the technique of direct georeferencing using metric digital camera system coupled to the laser system, and both systems were aided inertial navigation platform. For this, we compared the coordinates obtained in 16 control points collected in the field with dual-frequency GNSS （global navigation satellite system） receiver with those obtained in the orthophoto, flight conducted in June 2009 on the campus of the State University of Campinas--UNICAMP, using a medium format digital camera and laser system, with which we obtained images with a spatial resolution of 0.15 m. Taking into account the pattern accuracy cartographic used in Brazil, it is concluded that the products produced have a standard accuracy ＂A＂ to 1：2,000 scale, which represents the best quality level, both for planimetric as for altimetry, and that the procedure reached results consistent with cartographic products in 1：2,000 scale, representing a reduction of steps in the mapping process, necessary for the preparation of cartographic databases with reduction of time for preparation of design basis large civil engineering projects, such as roads, railways, studies of urban road systems, power plants and other infrastructure systems needed to develop the country.展开更多
With the rapid development and wide application of network technology, information security issues are increasingly highlighted, received more and more attention. This article introduces the present situation of netwo...With the rapid development and wide application of network technology, information security issues are increasingly highlighted, received more and more attention. This article introduces the present situation of network information security, discusses the connotation of network information security, and analyzes the main threat to the security of the network information. And we separately detailed description of the data monitoring platform architecture from the data layer, network layer and presentation layer three levels, focuses on the functional structure of intelligent database platform, and puts forward to measures that ensure the safety of the platform and the internal data security. Through the design of the platform to improve the information security system has certain significance.展开更多
The current study is developed based on one of the types of subgrade rupture risk suggested by Selig and Waters （1994）. It aims to evaluate subgrade stability railroad, which consists of the slope stability analysis...The current study is developed based on one of the types of subgrade rupture risk suggested by Selig and Waters （1994）. It aims to evaluate subgrade stability railroad, which consists of the slope stability analysis of a railway yard embankment subjected to a wagon load type gondola parked on this track. This proposed analysis was taken into consideration because there are Brazilian railroads in high deterioration level. In some of these lines the tracks are submitted to increasing amount of load every year. The adopted model slope stability to the studied railroad embankments considers the rupture on circular line. It was applied the Geoslope-Slope/W software, version 6, to the evaluation of the platform-slope system. Several situations are adopted to reach the minimum safety slope, permitting to analyze the platform stability to keep railroad traffic under adequate safety level.展开更多
基金Supported by the Open Foundation of the State Key Lab for Ocean Engineering of Shanghai Jiao Tong University under Grant No.0602
文摘An inevitable consequence of the development of the offshore petroleum industry is the eventual obsolescence of large offshore structures. Proper methods for removal of decommissioned offshore platforms are becoming an important topic that the oil and gas industry must pay increasing attention to. While removing sections from a decommissioned jacket platform, the stability of the remaining parts is critical The jacket danger indices D ~ and Ds defined in this paper are very useful for analyzing the safety of any procedure planned for disassembling a jacket platform. The safest piles cutting sequence can be determined easily by comparing every column of Do and Ds or simply analyzing the figures of every row ofD o and D,.
文摘This study aims to analyze the quality of positioning orthophoto generated through the technique of direct georeferencing using metric digital camera system coupled to the laser system, and both systems were aided inertial navigation platform. For this, we compared the coordinates obtained in 16 control points collected in the field with dual-frequency GNSS （global navigation satellite system） receiver with those obtained in the orthophoto, flight conducted in June 2009 on the campus of the State University of Campinas--UNICAMP, using a medium format digital camera and laser system, with which we obtained images with a spatial resolution of 0.15 m. Taking into account the pattern accuracy cartographic used in Brazil, it is concluded that the products produced have a standard accuracy ＂A＂ to 1：2,000 scale, which represents the best quality level, both for planimetric as for altimetry, and that the procedure reached results consistent with cartographic products in 1：2,000 scale, representing a reduction of steps in the mapping process, necessary for the preparation of cartographic databases with reduction of time for preparation of design basis large civil engineering projects, such as roads, railways, studies of urban road systems, power plants and other infrastructure systems needed to develop the country.
文摘With the rapid development and wide application of network technology, information security issues are increasingly highlighted, received more and more attention. This article introduces the present situation of network information security, discusses the connotation of network information security, and analyzes the main threat to the security of the network information. And we separately detailed description of the data monitoring platform architecture from the data layer, network layer and presentation layer three levels, focuses on the functional structure of intelligent database platform, and puts forward to measures that ensure the safety of the platform and the internal data security. Through the design of the platform to improve the information security system has certain significance.
文摘The current study is developed based on one of the types of subgrade rupture risk suggested by Selig and Waters （1994）. It aims to evaluate subgrade stability railroad, which consists of the slope stability analysis of a railway yard embankment subjected to a wagon load type gondola parked on this track. This proposed analysis was taken into consideration because there are Brazilian railroads in high deterioration level. In some of these lines the tracks are submitted to increasing amount of load every year. The adopted model slope stability to the studied railroad embankments considers the rupture on circular line. It was applied the Geoslope-Slope/W software, version 6, to the evaluation of the platform-slope system. Several situations are adopted to reach the minimum safety slope, permitting to analyze the platform stability to keep railroad traffic under adequate safety level.
