质量管理在中国香港的应用(英文)

香港工商企业的质量管理大部分都采用西方的质量管理概念。每当范畴扩展到建立人的优质思想和意识时，便遇到不少困难，基于上述问题，作者进行了一系列的研究，希望了解‘文化’与‘优质管理’之间的关系，并将中国的优良文化传统应用于现代质量管理之中。研究结果显示，‘管理哲学’是重要的一环，而我国的哲学极为丰富，作者借此文章，希望引起更多中国人在这方面的兴趣，从而进行更深入地研究和推广。     

Hypothesis-test-based landcover change detection using multi-temporal satellite images – A comparative study

Remote sensing images and technologies have been widely applied to environmental monitoring, in particular landuse/landcover classification and change detection. However, the uncertainties involved in such applications have not been fully addressed. In this paper two hypothesis-test-based change detection methods, namely the bivariate joint distribution method and the conditional distribution method, are proposed to tackle the uncertainties in change detection by making decisions based on the desired level of significance. Both methods require a data set of class-dependent no-change pixels to form the basis for class-dependent hypothesis test. Using an exemplar study area in central Taiwan, performance of the proposed methods are shown to be significantly superior to two other commonly applied methods (the post-classification comparison and the image differencing methods) in terms of the overall change detection accuracies. The conditional distribution method takes into consideration the correlation between digital numbers of the pre- and post-images and the effect of the known pre-image digital number on the range of the post-image digital number, and therefore yields the highest change detection accuracy. It is also demonstrated that the class-dependent change detection is crucial for accurate landuse/landcover change detection.     

Theoretical analysis of the sequential lobing technique

A theoretical analysis of the sequential lobing technique for target angle tracking is presented. The signal power received by each antenna beam is assumed to pass through a logarithmic amplifier. A rigorous statistical approach is adopted in the analysis for both non-fluctuating and fluctuating targets. Closed form expressions are derived for the normalized mean error and rms error of the angle estimate for Swerling 0, I, II, and III targets. Results are compared with those obtained using a simplified approach for the non-fluctuating target     

Hybrid boosters for Ariane 5

Results of a systems analysis are presented which investigates replacing Ariane 5's solid rocket boosters by LOX/polyethylene hybrids. Their advantages and disadvantages are discussed. A performance and mass breakdown is presented.     

Low-angle tracking using a multifrequency sampled aperture radar

The improvements that can be achieved in low-angle radar by using a sampled aperture radar (SAMPAR) and a maximum likelihood (ML) algorithm are discussed. The SAMPAR system described is unique in that it has a wide-ranging multifrequency capability. The ML technique is also unique because its estimation is based on the use of a highly refined signal model. It is shown, by using both simulated data and real data, that this combination, i.e., a SAMPAR system and the modified ML algorithm, provides a multiple signal resolution that exceeds any reported in the open literature. The measured data used in this study were recorded using a 32-element sampled aperture antenna on an over-water path     

具有两个测量控制面的适应壁风洞理论与实验

本文研究了具有两个测量控制面的适应壁风洞。在超临界马赫条件下,做了二维NACA-0012翼型实验。在近洞壁处的两个控制面上测取了静压。基于上述测量,叙述了在适应壁风洞中得到无干扰流场的迭代方法。给出了为外场计算这两个控制面上静压的函数关系。评述了所选取迭代方法的收敛性。得到了一步收敛公式,并且在数字模拟风洞中得到证实。结果指出,应用一步迭代公式,所选取的迭代方法可以加速使流场收敛到无界条件。     

适用于小型公司的 ISO 9000 质量管理系统(英文)

ＩＳＯ９０００质量管理系统往往存在一种神秘性。一般认为它只适用于大型公司，对小型公司而言，该系统实在是太昂贵了，本文澄清了这种错误的想法，并说明了ＩＳＯ９０００系统内在之属性事实上是灵活的，不论任何行业的小型公司均可适用。此外，它亦指出了认证审核员和质量管理顾问应对那些易犯的错误提高警觉。     

Flight path estimation using frequency measurements from a wideaperture acoustic array

A narrowband technique based on the acoustical Doppler effect is proposed for estimating the trajectory of a turbo-prop aircraft in level flight with constant velocity as it transits over a ground-based passive acoustic sensor array. The basic principle is to measure the temporal variation of the instantaneous frequency (IF) of the acoustic signal received by each sensor and then to minimize the sum of the squared deviations of the IF estimates from their predicted values over a sufficiently long period of time for all sensors. The technique provides estimates of the propeller blade rate and the five source motion parameters that describe the aircraft trajectory. The six dimensional minimization problem is reduced to a five dimensional maximization problem, which is solved numerically using the quasi-Newton method. A simple method is described that provides the initial parameter estimates required for the numerical maximization. The effectiveness of the motion parameter estimation technique is verified using real acoustic data recorded from a wide aperture microphone array during various transits of a turbo-prop aircraft     

Aircraft flight parameter estimation using acoustical Lloyd'smirror effect

A model is developed for the acoustical Lloyd's mirror effect observed in the output time-frequency distribution of a microphone located near the ground during the transit of a jet aircraft. The feasibility of using this effect for flight parameter estimation is assessed by a simple Cramer-Rao lower bound analysis. The nonlinear least-squares method and the generalized Hough transform method are formulated for flight parameter estimation. The performances of both methods are evaluated and compared using real acoustic data