A note on “Solving linear programming problems under fuzziness and randomness environment using attainment values”

This paper is an amendment to Hop’s paper [N.V. Hop, Solving linear programming problems under fuzziness and randomness environment using attainment values, Information Sciences 177 (2007) 2971-2984], in solving linear programming problems under fuzziness and randomness environments. Hop introduced a new characterization of relationship, attainment values, to enable the conversion of fuzzy (stochastic) linear programming models into corresponding deterministic linear programming models. The purpose of this paper is to provide a correction and an improvement of Hop’s analytical work through rationalization and simplification. More importantly, it is shown that Hop’s analysis does not support his demonstration or the solution-finding mechanism; the attainment values approach as he had proposed does not result in superior performance as compared to other existing approaches because it neglects some relevant and inevitable theoretical essentials. Two numerical examples from Hop’s paper are also employed to show that his approach, in the conversion of fuzzy (stochastic) linear programming problems to corresponding problems, is questionable and can neither find the maximum nor the minimum in the examples. The models of the examples are subsequently amended in order to derive the correct optimal solutions.     

Using local deviations of vectorization to enhance the performance of raster-to-vector conversion systems

This paper presents a method of quantitatively measuring local vectorization errors that evaluates the deviation of the vectorization of arbitrary (regular and irregular) raster linear objects. This measurement of the deviation does not depend on the thickness of the linear object. One of the most time-consuming procedures of raster-to-vector conversion of large linear drawings is manually verifying the results. Performance of raster-to-vector conversion systems can be enhanced with auto- localization of places that have to be corrected. The local deviations can be used for testing results and automatically showing the parts of resulting curves where deviations are greater than a threshold value and have to be corrected.     

Convertibility of Function Points into COSMIC Function Points: A study using Piecewise Linear Regression

Background

COSMIC Function Points and traditional Function Points (i.e., IFPUG Function Points and more recent variation of Function Points, such as NESMA and FISMA) are probably the best known and most widely used Functional Size Measurement methods. The relationship between the two kinds of Function Points still needs to be investigated. If traditional Function Points could be accurately converted into COSMIC Function Points and vice versa, then, by measuring one kind of Function Points, one would be able to obtain the other kind of Function Points, and one might measure one or the other kind interchangeably. Several studies have been performed to evaluate whether a correlation or a conversion function between the two measures exists. Specifically, it has been suggested that the relationship between traditional Function Points and COSMIC Function Points may not be linear, i.e., the value of COSMIC Function Points seems to increase more than proportionally to an increase of traditional Function Points.

Objective

This paper aims at verifying this hypothesis using available datasets that collect both FP and CFP size measures.

Method

Rigorous statistical analysis techniques are used, specifically Piecewise Linear Regression, whose applicability conditions are systematically checked. The Piecewise Linear Regression curve is a series of interconnected segments. In this paper, we focused on Piecewise Linear Regression curves composed of two segments. We also used Linear and Parabolic Regressions, to check if and to what extent Piecewise Linear Regression may provide an advantage over other regression techniques. We used two categories of regression techniques: Ordinary Least Squares regression is based on the usual minimization of the sum of squares of the residuals, or, equivalently, on the minimization of the average squared residual; Least Median of Squares regression is a robust regression technique that is based on the minimization of the median squared residual. Using a robust regression technique helps filter out the excessive influence of outliers.

Results

It appears that the analysis of the relationship between traditional Function Points and COSMIC Function Points based on the aforementioned data analysis techniques yields valid significant models. However, different results for the various available datasets are achieved. In practice, we obtained statistically valid linear, piecewise linear, and non-linear conversion formulas for several datasets. In general, none of these is better than the others in a statistically significant manner.

Conclusions

Practitioners interested in the conversion of FP measures into CFP (or vice versa) cannot just pick a conversion model and be sure that it will yield the best results. All the regression models we tested provide good results with some datasets. In practice, all the models described in the paper - in particular, both linear and non-linear ones - should be evaluated in order to identify the ones that are best suited for the specific dataset at hand.     

On the finite element solution of the elastoplastic axisymmetric Hertz contact problem

This paper includes a dimensionless treatment of the Hertz contact problem in the elastoplastic range, assuming the material in the bodies involved to be linear elastic and linear strain hardening. The bodies treated in this paper are assumed to be axisymmetric. Based upon the theoretical considerations in this work conversion formulas for engineering use are presented. The use of these formulas makes it possible to convert results from elastic plastic contact analysis for different yield stress and geometries. This will considerably reduce the number of calculations needed.     

An efficient joint implementation of three stages for fast computation of color space conversation in image coding/decoding

This paper proposes an efficient joint implementation algorithm for computing color space conversion, quantization and discrete cosine transform (DCT) in an image coder/decoder. By combining the three stages, the proposed algorithm reduces the operation amount of computing color space conversion considerably. In the case of color sampling 4:4:4, the proposed algorithm reduces the multiplication amount by 40% and the addition amount by 42% for the conversion from RGB to YCbCr in an image coder, and reduces the multiplication amount by 60% and the addition amount by 42% for the conversion from YCbCr to RGB in an image decoder. In the cases of down-sampling 4:2:2 and 4:1:1, there are the similar results. The existing fast methods in the literatures can still be applied together with this proposed algorithm into the implementation of the international image coding standards which use the transform coding technology, such as JPEG, MPEG and H.26X, and raises the image coding/decoding speed efficiently.     

Transforming Perceived Vocal Effort and Breathiness Using Adaptive Pre-Emphasis Linear Prediction

This paper presents a technique to transform high-effort voices into breathy voices using adaptive pre-emphasis linear prediction (APLP). The primary benefit of this technique is that it estimates a spectral emphasis filter that can be used to manipulate the perceived vocal effort. The other benefit of APLP is that it estimates a formant filter that is more consistent across varying voice qualities. This paper describes how constant pre-emphasis linear prediction (LP) estimates a voice source with a constant spectral envelope even though the spectral envelope of the true voice source varies over time. A listening experiment demonstrates how differences in vocal effort and breathiness are audible in the formant filter estimated by constant pre-emphasis LP. APLP is presented as a technique to estimate a spectral emphasis filter that captures the combined influence of the glottal source and the vocal tract upon the spectral envelope of the voice. A final listening experiment demonstrates how APLP can be used to effectively transform high-effort voices into breathy voices. The techniques presented here are relevant to researchers in voice conversion, voice quality, singing, and emotion.     

Balancing and model reduction for second-order form linear systems

Model reduction of second-order form linear systems is considered where a second-order form reduced model is desired, The focus is on reduction methods that employ or mimic Moore's balance and truncate (1981). First, we examine second-order form model reduction by conversion to first-order form and obtain a complete solution for this problem. Then, new Gramians and input/output (I/O) invariants for second-order systems are motivated and defined. Based on these, direct second-order balancing methods are developed. This leads naturally to direct second-order form analogs for the well-known first-order form balance and truncate model reduction method. Explicit algorithms are given throughout the paper     

A new method of real-time physical simulation of prime movers used in energy conversion chains

This paper focuses on exploring a new method of real-time replication of the dynamic behaviour of prime movers that drive rotating generators involved in energy conversion chains. Their behaviour depends on the mover’s mechanical characteristics and dynamical properties, such as inertia or friction coefficient, which are seldom known precisely. Being also dependent on the variations of the primary energy resource, not always controllable in its natural environment, this behaviour must be simulated by using a smaller and cheaper mover, whose model is sufficiently known such that to render it fully controllable. This paper explores the possibility that the desired real-time replication be achieved by means of a new method of tracking the mover’s rotational speed. To this end, various controllers, both linear and nonlinear can be employed. The design steps are provided for a PI controller, as well as for two nonlinear controllers, while focusing on the practical aspects of controller implementation. Their performance results are assessed comparatively on an experimental rig for two types of prime movers: one whose mechanical torque-speed characteristic is linear and a cross-flow water turbine, having a nonlinear torque-speed characteristic.     

Solvability of the decoupling problem for linear constant (A,B,C,D)-quadruples with regular output feedback

The aim of this paper is to deal with the general decoupling problem of linear constant (A, B, C, D)-quadruples under the assumption of (regular) output feedback. In its most general setting, this problem was hitherto unsolved. Here we give a complete characterization of solutions by (regular) output feedback by means of necessary and sufficient conditions of existence. They generalize the result previously obtained by Denham [4] for the linear constant (A, B, C)-triples.     

Direct manipulations of B-spline and NURBS curves

This paper presents a method for the direct manipulations of B-spline and non-uniform rational B-splines (NURBS) curves using geometric constraints. A deformable model is developed to define the deformation energy functional of B-spline and NURBS curves. The finite element method is used to minimize the deformation energy functional and solve for the deformed shape of curves subjected to constraints. This approach results in a set of linear equations for a B-spline curve and a set of non-linear equations for a NURBS curve. A perspective mapping is used to linearize the NURBS formulations. NURBS curves are first mapped from the 3D Cartesian coordinate space to the 4D homogeneous coordinate space, and transformed to 4D B-spline curves. After the manipulation in the 4D homogeneous coordinate space, the modified NURBS curves are then mapped back to the 3D Cartesian coordinate space. The approach is implemented by a prototype program, which is written in C, and runs under WINDOWS. Several examples are presented to demonstrate the capabilities of this approach.     

A Spectral Conversion Approach to Single-Channel Speech Enhancement

In this paper, a novel method for single-channel speech enhancement is proposed, which is based on a spectral conversion feature denoising approach. Spectral conversion has been applied previously in the context of voice conversion, and has been shown to successfully transform spectral features with particular statistical properties into spectral features that best fit (with the constraint of a piecewise linear transformation) different target statistics. This spectral transformation is applied as an initialization step to two well-known single channel enhancement methods, namely the iterative Wiener filter (IWF) and a particular iterative implementation of the Kalman filter. In both cases, spectral conversion is shown here to provide a significant improvement as opposed to initializations using the spectral features directly from the noisy speech. In essence, the proposed approach allows for applying these two algorithms in a user-centric manner, when "clean" speech training data are available from a particular speaker. The extra step of spectral conversion is shown to offer significant advantages regarding output signal-to-noise ratio (SNR) improvement over the conventional initializations, which can reach 2 dB for the IWF and 6 dB for the Kalman filtering algorithm, for low input SNRs and for white and colored noise, respectively     

基于准时制的炼钢-连铸生产调度问题研究

在钢铁CIMS下对于在安排炼钢-连铸调度中的机器冲突问题建立了基于准时制调度思想的数学模型,经过变换,将非线性规划问题转化为线性规划问题,用标准线性规划程序进行求解,使这一模型能够用于生产实际.最后给出了一个应用实例.     

C++任意数据类型转换的一种实现

在使用C++语言开发软件系统的过程中,数据转换是经常遇到的问题,例如将多种数据类型的变量转换为字符串形式输出,虽然已经有大量的库函数可以处理类似的问题,但是面对用户自定义的类型或用户特定需求是却只能逐个编写对应的处理函数,主要探讨使用C++模板编程技术来解决数据转换的问题。     

嵌入式系统在多功能精密高度测量仪中的应用

介绍了基于ARM920T内核的微处理器及WinCE系统的高度测量系统设计,给出了以S3C2410A芯片为核心的硬件设计的原理框图,详细阐述了S3C2410A核心模块电路、光栅尺传感器及其信号处理电路、电机控制电路以及系统软件的设计方法;该测量仪采用TFT-LCD+触摸屏,界面简洁,操作方便;所设计的高度测量仪可用于测量零件的高度、深度、槽宽、内外孔径、最高点、最低点、平面度、角度、2D测量、单一尺寸检验测量、测量公差等级控制,并内置温度补偿和光栅尺分段线性补偿,其测量分辨率可达0.5μm;经过用户两年多使用,表明该测量仪的性能完全满足设计要求。     

多线程技术在虚拟多串口通信中的应用

介绍了在VC＋＋编程环境下,利用多线程技术、Win32 API函数和重叠操作模式完成对USB接口转换器的虚拟多串口的监控,实现了对虚拟多串口数据的实时接收和处理,并通过串口通信实现了对远程数据采集器的控制。另对监控程序所涉及到的无阻塞后台运行等问题进行了分析。     

Representing coordination and non-coordination in American Sign Language animations

While strings and syntax trees are used by the Natural Language Processing community to represent the structure of spoken languages, these encodings are difficult to adapt to a signed language like American Sign Language (ASL). In particular, the multichannel nature of an ASL performance makes it difficult to encode in a linear single-channel string. This paper will introduce the Partition/Constitute (P/C) formalism, a new method of computationally representing a linguistic signal containing multiple channels. The formalism allows coordination and non-coordination relationships to be encoded between different portions of a signal. The P/C formalism will be compared to representations used in related research in gesture animation. The way in which P/C is used by this project to build an English-to-ASL machine translation system will also be discussed.     

ST-OFDM系统载波干扰抑制技术研究

分析了ST-OFDM系统中载波间干扰的具体内容，提出了一种ST-OFDM系统中载波间干扰线性抑制技术，利用连续发射已知ST-OFDM符号来估计ST-OFDM中各个子载波对其他子载波的干扰，然后通过特定的线性运算达到ST-OFDM载波间干扰的抑制。仿真结果表明，使用与不使用载波干扰抑制技术ST-OFDM系统可获得至少4dB性能增益，而且选择6～10个相邻子载波干扰系数可以使ST-OFDM系统在性能和运算量上获得最佳。莱斯衰落信道下该线性抑制方法可较有效克服ST-OFDM系统的载波间干扰。     

Identification of linear dynamic systems operating in a networked environment

This paper studies a networked system identification problem, which aims at identifying mathematical models required in networked control/estimation/filtering systems. Specifically, we consider the off-line identification of open-loop stable linear time-invariant processes working in a networked environment. In the networked environment, how the actuators (D/A conversion) operate plays a key role in the complexity of the related identification problems. In particular, it is reasonable to consider the configuration of event-driven actuators subject to random network-induced delays and packet dropouts; as a result, the networked identification problem is formulated as the one to identify continuous-time linear time-invariant models, based on the general non-uniformly non-synchronized sampled data. A modified version of the simplified refined instrumental variable method is proposed to solve this problem, and is validated in a networked identification experiment based on the Matlab/Simulink simulator TrueTime.     

一种网格环境下的异构数据库转换方法

网格是一个集成的计算机环境和资源环境,异构数据资源的交换是网格技术的基础。利用XML文档作为网格下异构数据库转换的中间件,重点研究一种基于DOM的映射方法以实现XML文档和数据库之间的转换,详细介绍了转换方法,并通过GT4部署网格服务得以实现。