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991.
Context
Information system development (ISD) has been plagued with high failure rates. This is partially due to the activities being a combination of both a technical and social processes involving stakeholders with conflicting interests.Objective
Existing software risk management theories and frameworks offer limited suggestions for actions that can be taken to reduce the chance of failure of ISD projects. Our objective is to examine the connections among some of the more important user related risks in order to shed light on how specific strategies enhance the chance of project success.Method
We conducted a sample of information systems project managers to test a multivariate model to explain the impact of pursuing a partnership with users on the conflicts that arise between users and developers, role ambiguity, and subsequent impact on project performance.Results
The proposed model was supported, suggesting that user-developer conflict and role ambiguity have a negative impact on performance estimation difficulty, which negatively affects project performance.Conclusion
Pursuit of project partnering yields a number of significant relationships in the model indicating an organization can implement practices that reduce risks associated with role ambiguity and conflict in system development projects. 相似文献992.
针对浊音、清音和噪声的不同特性,结合听觉掩蔽并使用随尺度变化的多阈值对语音信号进行处理.提出了多小波门限估计法,该方法针对不同声音成分,使用不同的与尺度有关的缩小因子调节门限值;通过估计各频带内的信噪比,实现了阈值的时频自适应变化;用巴克小波包分解法模拟人耳临界带特性,用小波谱减法对带噪语音进行预增强,采用Johnst... 相似文献
993.
非参数回归模型均值函数结构变点的检测与应用 总被引:1,自引:0,他引:1
本文将一类系统参数变点检测问题转化为非参数回归模型均值函数结构变点的检测问题.针对当非参数模型均值函数跃度的长期均值为零时,残量累积和(cumulative sum,CUSUM)统计量无效的问题,首先利用均值函数的核估计构造新统计量,给出了原假设和备择假设下统计量的极限分布;进一步构造Bootstrap检验,证明了Bootstrap检验的一致性;最后以模拟结果表明新方法明显优于已有的方法,并应用于两类实际数据分析,说明方法的有效性. 相似文献
994.
基于伪测量的分布式最优单步延迟航迹融合估计 总被引:1,自引:0,他引:1
融合中心如何处理无序局部数据,对分布式多传感器系统的运行品质至关重要.本文将系统中的局部估计转化为伪测量,将分布式融合估计转化为二级集中式融合估计.将所得的伪测量兼分布式融合估计算法与单步延迟的无序测量数据(out-of-sequencemeasurements,OOSM)最优滤波-A1算法进行组合,得出了分布式多传感器系统的最优单步延迟无序航迹(out-of-sequence tacks,OOST)估计算法,适用于航迹无序局部数据融合估计.该算法具有最优估计性能. 相似文献
995.
996.
研究了在观测中存在Markov跳跃时滞的离散时间系统的线性最小方差状态估计问题. 首先, 通过引入跳跃时滞的示性函数, 将带有跳跃时滞的观测方程转化为带有乘性噪声的定常时滞系统. 进一步采用状态扩维的方法, 将定常时滞系统转化为无时滞的Markov跳跃系统. 最后, 基于得到的无时滞系统, 采用Hilbert空间已有的几何论知识, 设计线性最优状态估计器, 得出基于Riccati方程的滤波器的表达式, 并证明了所得滤波器的渐渐收敛性. 相似文献
997.
While equilibrium analysis has been commonly used for network pricing under the assumption that user utility functions are precisely known, many researchers have criticized the validity of the assumption. In this paper, we propose a solution for bridging the gap between the existing theoretical work on optimal pricing and the unavailability of precise user utility information in real networks. In the proposed method, the service provider obtains increasingly more accurate estimates of user utility functions by iteratively changing the prices of service levels and observing the users’ service-level choices under various prices. Our study’s contribution is twofold. First, we have developed a general principle for estimating user utility functions. Especially, we present the utility estimation for dynamic user population. Second, we have developed a method for setting prices that can optimize the extraction of information about user utility functions. The extensive simulation results demonstrate the effectiveness of our method. 相似文献
998.
HUANG Yi CHEN ZongJi & WEI Chen National Key Laboratory of Science Technology on Integrated Control Technology School of Automation Science Electric Engineering Beihang University Beijing China 《中国科学:信息科学(英文版)》2010,(2):258-270
To improve the consistency of estimation result, a least-trace extended set-membership filter (LTESMF) is presented for a class of nonlinear stochastic systems, which has linear output and unknown- but-bounded noise. Feedback technique is used instead of the intersection of ellipsoid-sets in the measurement update. The feedback parameter is optimized in order to minimize the trace of error bounded ellipsoid’s envelop matrix. A new stability analysis method was developed to prove the stochastic system’s stab... 相似文献
999.
1000.
The paper provides comparison of three different approaches to on-line tuning of generalized adaptive notch filters (GANFs) — the algorithms used for identification/tracking of quasi-periodically varying dynamic systems. Tuning is needed to adjust adaptation gains, which control tracking performance of GANF algorithms, to the unknown and/or time time-varying rate of system nonstationarity. Two out of three compared approaches are classical solutions — the first one incorporates sequential optimization of adaptation gains while the second one is based on the concept of parallel estimation. The main contribution of the paper is that it suggests the third way — it shows that the best results can be achieved when both approaches mentioned above are combined in a judicious way. Such joint sequential/parallel optimization preserves advantages of both treatments: adaptiveness (sequential approach) and robustness to abrupt changes (parallel approach). Additionally the paper shows how, using the concept of surrogate outputs, one can extend the proposed single-frequency algorithm to the multiple frequencies case, without falling into the complexity trap known as the “curse of dimensionality”. 相似文献