AIM:To evaluate the effect of computed tomography(CT) attenuation values of ascites on gastrointestinal(GI) perforation site prediction.METHODS:The CT attenuation values of the ascites from 51 patients with GI perfora...AIM:To evaluate the effect of computed tomography(CT) attenuation values of ascites on gastrointestinal(GI) perforation site prediction.METHODS:The CT attenuation values of the ascites from 51 patients with GI perforations were measured by volume rendering to calculate the mean values.The effect of the CT attenuation values of the ascites on perforation site prediction and postoperative complications was evaluated.RESULTS:Of 24 patients with colorectal perforations,the CT attenuation values of ascites were significantly higher than those in patients with perforations at other sites [22.5 Hounsfield units(HU) vs 16.5 HU,respectively,P = 0.006].Colorectal perforation was significantly associated with postoperative complications(P = 0.038).The prediction rate of colorectal perforation using attenuation values as an auxiliary diagnosis improved by 9.8% compared to that of CT findings alone(92.2% vs 82.4%).CONCLUSION:The CT attenuation values of ascites could facilitate the prediction of perforation sites and postoperative complications in GI perforations,particularly in cases in which the perforation sites are difficult to predict by CT findings alone.展开更多
Milling Process Simulation is one of the important re search areas in manufacturing science. For the purpose of improving the prec ision of simulation and extending its usability, numerical algorithm is more and more ...Milling Process Simulation is one of the important re search areas in manufacturing science. For the purpose of improving the prec ision of simulation and extending its usability, numerical algorithm is more and more used in the milling modeling areas. But simulative efficiency is decreasin g with increase of its complexity. As a result, application of the method is lim ited. Aimed at above question, high-efficient algorithm for milling process sim ulation is studied. It is important for milling process simulation’s applicatio n. Parallel computing is widely used to solve the large-scale computation question s. Its advantages include system flexibility, robust, high-efficient computing capability and high ratio of performance to price. With the development of compu ter network, utilizing the computing resource in the Internet, a virtual computi ng environment with powerful computing capability can be consisted by microc omputers, and the difficulty of building hardware environment which is used to s upport parallel computing is reduced. How to use network technology and parallel algorithm to improve simulative effic iency for milling forces simulation is investigated in the paper. In order to pr edict milling forces, a simplified local milling forces model is used in the pap er. End milling cutter is assumed to be divided by r number of differential elem ents along the axial direction of the cutter. For a given time, the total cuttin g forces can be obtained by summarizing the resultant cutting force produced by each differential cutter disc. Divide the whole simulative time into some segmen ts, send these program’s segments to microcomputers in the Internet and obtain the result of the program’s segments, all of the result of program’s segments a re composed the final result. For implementing the algorithm, a distributed Parallel computing framework is de signed in the paper. In the framework, web server plays a role of controller. Us ing Java RMI(remote method interface), the computing processes in computing serv er are called by web server. There are lots of control processes in web server a nd control the computing servers. The codes of simulative algorithm can be dynam ic sent to the computing servers, and milling forces at the different time are c omputed through utilizing the local computer’s resource. The results that are ca lculated by every computing servers are sent to the web server, and composed the final result. The framework can be used by different simulative algorithm. Comp ared with the algorithm running single machine, the efficiency of provided algor ithm is higher than that of single machine.展开更多
我国对动态负压射孔技术基本作用机理的认识处在入门阶段,无法使动态负压作用原理量化成较为合适的动态负压计算模型,并编制成相应的射孔方案设计软件指导生产实践。为此,通过大量理论研究和试验研究,利用VS.NET软件及SQL Server 2005...我国对动态负压射孔技术基本作用机理的认识处在入门阶段,无法使动态负压作用原理量化成较为合适的动态负压计算模型,并编制成相应的射孔方案设计软件指导生产实践。为此,通过大量理论研究和试验研究,利用VS.NET软件及SQL Server 2005软件开发了动态负压射孔方案优化设计软件。对该软件的各个功能模块进行了介绍,同时结合吉林油田某口井的实际数据对软件进行了应用。应用结果表明,软件优化的射孔方案可以有效降低射孔表皮以及施工成本,可输出完整的射孔方案设计报告。展开更多
文摘AIM:To evaluate the effect of computed tomography(CT) attenuation values of ascites on gastrointestinal(GI) perforation site prediction.METHODS:The CT attenuation values of the ascites from 51 patients with GI perforations were measured by volume rendering to calculate the mean values.The effect of the CT attenuation values of the ascites on perforation site prediction and postoperative complications was evaluated.RESULTS:Of 24 patients with colorectal perforations,the CT attenuation values of ascites were significantly higher than those in patients with perforations at other sites [22.5 Hounsfield units(HU) vs 16.5 HU,respectively,P = 0.006].Colorectal perforation was significantly associated with postoperative complications(P = 0.038).The prediction rate of colorectal perforation using attenuation values as an auxiliary diagnosis improved by 9.8% compared to that of CT findings alone(92.2% vs 82.4%).CONCLUSION:The CT attenuation values of ascites could facilitate the prediction of perforation sites and postoperative complications in GI perforations,particularly in cases in which the perforation sites are difficult to predict by CT findings alone.
文摘Milling Process Simulation is one of the important re search areas in manufacturing science. For the purpose of improving the prec ision of simulation and extending its usability, numerical algorithm is more and more used in the milling modeling areas. But simulative efficiency is decreasin g with increase of its complexity. As a result, application of the method is lim ited. Aimed at above question, high-efficient algorithm for milling process sim ulation is studied. It is important for milling process simulation’s applicatio n. Parallel computing is widely used to solve the large-scale computation question s. Its advantages include system flexibility, robust, high-efficient computing capability and high ratio of performance to price. With the development of compu ter network, utilizing the computing resource in the Internet, a virtual computi ng environment with powerful computing capability can be consisted by microc omputers, and the difficulty of building hardware environment which is used to s upport parallel computing is reduced. How to use network technology and parallel algorithm to improve simulative effic iency for milling forces simulation is investigated in the paper. In order to pr edict milling forces, a simplified local milling forces model is used in the pap er. End milling cutter is assumed to be divided by r number of differential elem ents along the axial direction of the cutter. For a given time, the total cuttin g forces can be obtained by summarizing the resultant cutting force produced by each differential cutter disc. Divide the whole simulative time into some segmen ts, send these program’s segments to microcomputers in the Internet and obtain the result of the program’s segments, all of the result of program’s segments a re composed the final result. For implementing the algorithm, a distributed Parallel computing framework is de signed in the paper. In the framework, web server plays a role of controller. Us ing Java RMI(remote method interface), the computing processes in computing serv er are called by web server. There are lots of control processes in web server a nd control the computing servers. The codes of simulative algorithm can be dynam ic sent to the computing servers, and milling forces at the different time are c omputed through utilizing the local computer’s resource. The results that are ca lculated by every computing servers are sent to the web server, and composed the final result. The framework can be used by different simulative algorithm. Comp ared with the algorithm running single machine, the efficiency of provided algor ithm is higher than that of single machine.
文摘我国对动态负压射孔技术基本作用机理的认识处在入门阶段,无法使动态负压作用原理量化成较为合适的动态负压计算模型,并编制成相应的射孔方案设计软件指导生产实践。为此,通过大量理论研究和试验研究,利用VS.NET软件及SQL Server 2005软件开发了动态负压射孔方案优化设计软件。对该软件的各个功能模块进行了介绍,同时结合吉林油田某口井的实际数据对软件进行了应用。应用结果表明,软件优化的射孔方案可以有效降低射孔表皮以及施工成本,可输出完整的射孔方案设计报告。
