期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
对合理设置拦标价的探讨 被引量:7
1
作者 周洁 《江汉石油职工大学学报》 2008年第3期51-53,共3页
拦标价的设置目的是将相关工程的招标价格限定在合理的范围内,从而防止行业内的恶性低价竞争,确保工程质量。确定拦标价的重要依据是社会平均成本。拦标价是一个合理的价格区间,对高于其上限的投标,可作废标处理;对低于其下限的投标,投... 拦标价的设置目的是将相关工程的招标价格限定在合理的范围内,从而防止行业内的恶性低价竞争,确保工程质量。确定拦标价的重要依据是社会平均成本。拦标价是一个合理的价格区间,对高于其上限的投标,可作废标处理;对低于其下限的投标,投标人须接受评标小组的质询,通过质询方可中标,否则亦作废标处理。 展开更多
关键词 价格 拦标 工程施工
下载PDF
拦标控制价编制方法
2
作者 程富 叶建炳 宋妍 《黑龙江水利科技》 2011年第6期123-123,共1页
目前黑龙江省水利工程建设项目施工招标实行拦标控制价,结合工作实际简述采用现行水利行业定额编制拦标控制价的编制方法和思路。
关键词 拦标控制价 编制方法 定额 基础价格 建筑工程单价 临时设施费
下载PDF
Study on Mobile Object Tracking and Intercept Technology Research
3
作者 Sun Jun 《International Journal of Technology Management》 2014年第8期131-133,共3页
Background difference method[l] is one of the effective paths of improving robot' s vision reaction ability, and robots use background difference method to find the moving object in vision range and conduct tracking ... Background difference method[l] is one of the effective paths of improving robot' s vision reaction ability, and robots use background difference method to find the moving object in vision range and conduct tracking monitoring of moving objects. Then it uses support vector to conduct learning fitting of moving object, which can effectively predict the moving trend of moving object, and then it fabricates corresponding decision programs to conduct intercept capture of moving objects. 展开更多
关键词 moving object support vector machine(SVM) tracking intercept
下载PDF
Coverage-based cooperative target acquisition for hypersonic interceptions 被引量:9
4
作者 ZHOU Jin LEI HuMin 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2018年第10期1575-1587,共13页
This paper presents a novel coverage-based cooperative target acquisition algorithm for hypersonic interceptions. Firstly, the difficulties in the hypersonic trajectory prediction are introduced which invalidate the c... This paper presents a novel coverage-based cooperative target acquisition algorithm for hypersonic interceptions. Firstly, the difficulties in the hypersonic trajectory prediction are introduced which invalidate the conventionally used predicted impact point based mid-course guidance and seeker acquisition. Secondly, in order to optimally estimate and predict the target trajectory information, the interacting multiple model(IMM) algorithm is used with the constant velocity(CV) model, the constant acceleration(CA) model and the Singer model serving as the model set. The target states are described with the probability density function(PDF) based on the IMM prediction. Thirdly, the interceptor seeker target acquisition model is established which considers the blur edge region of the field of view. The cooperative target acquisition algorithm is designed by maximizing the interceptor seekers cooperative coverage of the target high probability region(HPR). Finally, digital simulations prove the effectiveness of the proposed method and reveal that the real challenge in the hypersonic target acquisition is the poor trajectory prediction accuracy which may further result to the unsteadiness of the interceptor trajectories. 展开更多
关键词 cooperative coverage target acquisition hypersonic interception IMM trajectory prediction midcourse guidance
原文传递
Performance of 3D TPN against true-arbitrarily maneuvering target for exoatmospheric interception 被引量:10
5
作者 LI KeBo LIANG YanGang +1 位作者 SU WenShan CHEN Lei 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2018年第8期1161-1174,共14页
True proportional navigation(TPN) guidance law is widely used for exoatmospheric interception, for its robustness and ease of implementation. The performance of TPN against nonmaneuvering target or the maneuvering tar... True proportional navigation(TPN) guidance law is widely used for exoatmospheric interception, for its robustness and ease of implementation. The performance of TPN against nonmaneuvering target or the maneuvering target with a specific acceleration had been analyzed before. However, the obtained results are not suitable for the realistic exoatmospheric interception scenario,since the target may maneuver along an arbitrary direction with an arbitrary but upper-bounded acceleration in the threedimensional(3 D) space, which is the so-called "true-arbitrarily maneuvering target" in this paper. With the help of the line-ofsight(LOS) rotation coordinate system, the performance of 3 D TPN against the true-arbitrarily maneuvering target is thoroughly analyzed using the Lyapunov-like approach. The upper-bound of the 3 D LOS rate is obtained, and so is that of the commanded acceleration of 3 D TPN. After that, the capture region of 3 D TPN is presented on the initial relative velocity plane. The nonlinear3 D relative kinematics between the interceptor and the target is taken into full account. Finally, the new theoretical findings are demonstrated by numerical simulations. 展开更多
关键词 exoatmospheric interception 3D TPN true-arbitrarily maneuvering target capturability Lyapunov-like approach
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部