关于机器人姿态偏差描述方法的讨论

本文针对国际标准草案 ISO/DP9283中用欧拉角的偏差描述机器人姿态偏差的规定,作者认为三个欧拉角的偏差没有独立的物理意义,不反映机器人姿态偏差的大小,这种描述方法十分不妥;主张以一次转动的转角描述机器人的姿态偏差。     

浅析数控曲轴连杆轴颈车床夹具设计的有效改进

数控曲轴连杆颈车床用来加工一般四拐曲轴的连杆颈,该夹具已使用多年,但随着近年来新产品开发数量的增多,已远不能满足使用要求,本文就CF-702数控曲轴连杆轴颈车床的夹具设计,进行有效的改进,具有一定的参考价值。     

全站仪竖井平面联系测量的方法及精度分析

随着测绘科学技术的不断发展,全站仪测量精度的不断提高,它已逐步取代了经纬仪在矿山测量应用中的主导地位。本文介绍了利用全站仪进行竖井联系测量的方法,并结合实例,重点对此方法的测量结果的精度进行了分析。     

绿色建筑采光模拟软件的适用性分析与计算精度验证

建筑采光模拟软件对绿色建筑设计有不可或缺的作用.文章首先阐述了建筑采光模拟软件的种类及特性,然后对4款采光软件的适用性进行分析,最后选取3款适用性较强的软件,通过实测与模拟对比的方法验证了软件的计算精度.     

The Delphi method, impeachment and terrorism: Accuracies of short-range forecasts for volatile world events

Two experiments examined the effects of iterated polling and feedback on prediction accuracy for volatile world events using the Delphi paradigm. In both experiments, participants predicted rapidly changing geopolitical events. The first experiment occurred during the litigation surrounding the Clinton/Lewinsky affair in 1998. Results indicated that feedback improved individual and group accuracy for predictions of whether an event would occur. These types of predictions derived from group consensus were approximately 90% accurate, which was significantly higher than the average individual participant's accuracy. Neither polling nor feedback had much effect on time course predictions. The second experiment occurred during the American military action against the Taliban regime in Afghanistan in 2001. In Experiment 2, participants were polled three times to determine if increasing the number of iterated polls would improve Delphi accuracy. The results showed that accuracy improved from the first to the second poll but not from the second to the third. The groups predicted whether these scenarios would occur with approximately 75% accuracy, which was significantly higher than the accuracy of any individual participant. Once again, the Delphi procedure did not enhance time course predictions in Experiment 2.     

Does the financial analysts' usage of non-financial information influence the analysts' forecast accuracy? Some evidence from the Belgian sell-side financial analyst

This paper examines whether the use of non-financial information by sell-side financial analysts influences the accuracy of analysts’ forecasts. The research findings, based on a survey of Belgian financial analysts, suggest that financial analysts who use more forward-looking information and more internal-structure information offer more accurate forecasts. Furthermore, the listed Belgian firms examined in this study have improved their non-financial information reporting over time. However, neither the frequency nor the quantity of non-financial information mentioned by financial analysts in their reports appears to have increased over time.     

An Empirical Analysis of the Bias and Rationality of Profit Forecasts Published in New Issue Prospectuses

Our study sets out to assess the accuracy of profit forecasts made by IPOs in Hong Kong. We use a variety of measures and tests to examine the accuracy, bias, rationality, and superiority of earnings estimates. The results show that forecast accuracy compares favourably with the findings from the developed economies of Australia, Britain, Canada, and New Zealand. Forecasts are shown to be superior to the predictions from time series models. IPOs tend to underforecast in the sense that actual profits exceed the forecasts. The rationality tests show mixed results. Cross-sectional analyses of forecast accuracy have poor explanatory power although the Big Six reporting accountants are associated with smaller forecast errors.     

NLOS环境下移动台位置与速率估计

NLOS (Non-line of Sight)误差是定位中的主要误差来源,直接影响了定位的精度 。在MIMO（Multiple Input Multiple Output）系统中,基于NLOS信道模型的定位方法成为 解决NLOS定位误差问题的利器。基于此提出一种新颖的几何方法,仅采用两条NLOS路径就可 计算MS(Mobile Station)的位置,并且只需要利用单个基站便可完成MS的定位,克服了基站 数目过少无法准确定位MS的缺陷。在此基础上,还给出了最小二乘与最大似然算法利用多条 NLOS路径来改善定位精度的方法,并利用它对NLOS环境下运动的MS进行定位跟踪。理论分析 和仿真结 果都证明该定位方法在NLOS环境中对MS定位的有效性与精确度。     

THE IMPACT OF POINT‐OF‐SALE DATA INACCURACY AND INVENTORY RECORD DATA ERRORS

The presence or absence of error in point‐of‐sale (POS) data and inventory system records directly affects retailer performance. This study identifies various error sources in retail supply chains and studies the influence of inventory and POS (demand) errors in a simulated retail outlet according to fill rate and average inventory. Other things being equal, we find that inventory record error reduces fill rate more than demand error. This study adds further evidence to other studies that suggest the costs caused by errors in POS systems may be overstated.     

Modelling property values in Nigeria using artificial neural network

Unreliable and inaccurate property valuation has been associated with techniques currently used in property valuation. A possible explanation for these findings may be due to the utilisation of traditional valuation methods. In the current study, an artificial neural network (ANN) is applied in property valuation using the Lagos metropolis property market as a representative case. Property sales transactions data (11 property attributes and property value) were collected from registered real estate firms operating in Lagos, Nigeria. The result shows that the ANN model possesses a good predictive ability, implying that it is suitable and reliable for property valuation. The relative importance analysis conducted on the property attributes revealed that the number of servants’ quarters is the most important attribute affecting property values. The findings suggest that the ANN model could be used as a tool by real estate stakeholders, especially valuers and researchers for property valuation.