关于富气压缩机的随动反喘振控制在PROVOX工程集散控制系统上的应用

广州石油化工总厂催化裂化装置于1978年建成投产,是采用美国FISHER控制设备公司的PROVOX工程集散控制系统.今年经改造年处理能力由原来的120万吨提高到150万吨.自控方面改造的重点是新增的气压机(机503/4)进DCS的自控方案,该方案自行设计组态、安装、调试和投用.该富气压缩机是离心式压缩机.因为喘振是离心压缩机所固有的特性,所以随动反喘振控制方案就是这次设计的核心.     

DT-II:Digital twin enhanced Industrial Internet reference framework towards smart manufacturing

In this paper, the interplay and relationship between digital twin and Industrial Internet are discussed at first. The sensing/transmission network capability, which is one of the main characteristics of Industrial Internet, can be a carrier for providing digital twin with a means of data acquisition and transmission. Conversely, with the capability of high-fidelity virtual modeling and simulation computing/analysis, digital twin evolving from lifecycle management for a single product to application in production/manufacturing in the shop-floor/enterprise, can further greatly enhance the simulation computing and analysis of Industrial Internet. This paper proposes a digital twin enhanced Industrial Internet (DT-II) reference framework towards smart manufacturing. To further illustrate the reference framework, the implementation and operation mechanism of DT-II is discussed from three perspectives, including product lifecycle level, intra-enterprise level and inter-enterprise level. Finally, steam turbine is taken as an example to illustrate the application scenes from above three perspectives under the circumstance of DT-II. The differences between with and without DT-II for design and development of steam turbine are also presented.     

PAG – an efficient program analyzer generator

The program analyzer generator PAG described in this paper attempts to offer the best of both worlds, specification languages based on the clean theory of abstract interpretation and efficient implementation methods from the theory of data flow analysis. PAG has a high level functional input language to specify data flow analyses. It offers the generation of complex data structures and is therefore not limited to bit vector problems. PAG generated interprocedural analyzers can be easily integrated into existing compilers. PAG has successfully been used in the ESPRIT project COMPARE to generate several analyzers (including alias analysis and constant propagation) for industrial quality ANSI-C and Fortran90 compilers, and is now marketed by the spin-off company AbsInt.A simplified version of PAG can be interactively tested over the Web.     

Compositional Analysis of C/C++ Programs with VeriSoft

This paper describes how the state space exploration ool VeriSoft can be used to analyze parallel C/C++ programs compositionally. VeriSoft is employed for two analyses: transition traceanalysis and assume/guarantee reasoning. Both analyses are compositional in the sense that the behaviour of a parallel program is determined in terms of the behaviour of its constituent processes. While both analyses have traditionally been carried out with “pencil and paper”, the paper demonstrates how VeriSoft can be used to automate them. In the context of transition trace analysis, the question whether a given program can exhibit a given trace is addressed with VeriSoft. To implement assume/guarantee reasoning, VeriSoft is used to determine whether a given program satisfies a given assume/guarantee specification. Since VeriSoft’s state space exploration is bounded and thus not complete in general, our proposed analyses are only meant to complement standard reasoning about parallel programs using traces or assume/guarantee specifications. For instance, a successful analysis does not always imply the general correctness of an assume/guarantee specification. However, it increases the confidence in the verification effort. On the other hand, an unsuccessful analysis always produces a counterexample which can be used to correct the specification or the program. VeriSoft’s optimization and visualization techniques make the analyses relatively efficient and effective.     

The Clara framework for hybrid typestate analysis

A typestate property describes which operations are available on an object or a group of inter-related objects, depending on this object??s or group??s internal state, the typestate. Researchers in the field of static analysis have devised static program analyses to prove the absence of typestate-property violations on all possible executions of a given program under test. Researchers in runtime verification, on the other hand, have developed powerful monitoring approaches that guarantee to capture property violations on actual executions. Although static analysis can greatly benefit runtime monitoring, up until now, most static analyses are incompatible with most monitoring tools. We present Clara, a novel framework that makes these approaches compatible. With Clara, researchers in static analysis can easily implement powerful typestate analyses. Runtime-verification researchers, on the other hand, can use Clara to specialize AspectJ-based runtime monitors to a particular target program. To make aspects compatible to Clara, the monitoring tool annotates them with so-called dependency state machines. Clara uses the static analyses to automatically convert an annotated monitoring aspect into a residual runtime monitor that is triggered by fewer program locations. If the static analysis succeeds on all locations, this proves that the program fulfills the stated typestate properties, making runtime monitoring entirely obsolete. If not, the residual runtime monitor is at least optimized. We instantiated Clara with three static typestate analyses and applied these analyses to monitoring aspects generated from tracematches. In two-thirds of the cases in our experiments, the static analysis succeeds on all locations, proving that the program fulfills the stated properties, and completely obviating the need for runtime monitoring. In the remaining cases, the runtime monitor is often significantly optimized.     

双岛结构硅压力传感器的非线性内补偿研究􀀁

本文指出采用矩形双岛结构可以实现硅压力传感器的非线性内补偿，用一维近似模型分析计算了矩形双岛结构硅压力传感器硅芯片的应力分布及其与（１００）硅各向异性腐蚀深度的关系，指出对已确定了几何尺寸的掩膜，可以找到某一最佳腐蚀深度，使这时两对力敏电阻所受横向应力大小与其非线性值成反比，这样总的非线性零值，通过实验证实了这一结论。     

一个面向C和Fortran数值程序的静态分析工具

程序的正确性验证一直以来都是计算机科学中的一个挑战性问题,抽象解释理论为程序静态分析提供了一个通用框架,可以在编译时自动地推导程序的动态性质。基于抽象解释的数值程序分析可以自动推导程序中数值变量间的不变式关系,这对于编译优化、程序错误检查至关重要。本文建立并实现了一个面向C和Fortran程序并支持过程间分析的数值程序分析框架和工具,C或Fortran源程序经过预处理后转化为具有统一格式的中间表示形式,然后基于该中间表示抽取与源程序语义等价的语义等式,最后在该语义等式上进行不动点迭代计算从而得到程序不变式。在此基础上,本文还对数组等复杂语法结构进行了建模和抽象。实验结果表明,该工具具有较高的可扩展性、精度,并能够处理大部分因数组的使用而带来的程序分析上的问题。     

Modular Pluggable Analyses for Data Structure Consistency

Hob is a program analysis system that enables the focused application of multiple analyses to different modules in the same program. In our approach, each module encapsulates one or more data structures and uses membership in abstract sets to characterize how objects participate in data structures. Each analysis verifies that the implementation of the module 1) preserves important internal data structure consistency properties and 2) correctly implements a set algebra interface that characterizes the effects of operations on the data structure. Collectively, the analyses use the set algebra to 1) characterize how objects participate in multiple data structures and to 2) enable the interanalysis communication required to verify properties that depend on multiple modules analyzed by different analyses. We implemented our system and deployed several pluggable analyses, including a flag analysis plug-in for modules in which abstract set membership is determined by a flag field in each object, a PALE shape analysis plug-in, and a theorem proving plug-in for analyzing arbitrarily complicated data structures. Our experience shows that our system can effectively 1) verify the consistency of data structures encapsulated within a single module and 2) combine analysis results from different analysis plug-ins to verify properties involving objects shared by multiple modules analyzed by different analyses     

基于切片技术的并行化研究

程序可以看作由很多计算组成(例如一个循环或一个平直代码片断),它们彼此相关或者无关,共同为计算最终的结果服务,其中彼此不相关的计算是并行性的重要来源。程序切片(Program Slicing)是一种程序分解技术,能够根据切片标准从程序中提取出特定的计算,切片技术的应用很广泛,例如程序调试、理解、维护等软件工程应用。切片技术作为一项程序分解技术,也可以用来帮助串行程序并行化。研究利用切片技术表示和发掘程序中的无关计算带来的并行性。首先提出一种基于OpenMP扩展的切片并行编程模型,用以表达程序中的切片并行性。另外,开发了一个基于切片的并行化分析系统,用来辅助程序员发掘程序中的切片并行性。     

Development of dynamic protection against timing channels

Information systems face many threats, such as covert channels, which declassify hidden information by, e.g., analyzing the program execution time. Such threats exist at various stages of the execution of instructions. Even if software developers are able to neutralize these threats in source code, new attack vectors can arise in compiler-generated machine code from these representations. Existing approaches for preventing vulnerabilities have numerous restrictions related to both their functionality and the range of threats that can be found and removed. This study presents a technique for removing threats and generating safer code using dynamic compilation in an execution environment by combining information from program analysis of the malicious code and re-compiling such code to run securely. The proposed approach stores summary information in the form of rules that can be shared among analyses. The annotations enable us to conduct the analyses to mitigate threats. Developers can update the analyses and control the volume of resources that are allocated to perform these analyses by changing the precision. The authors’ experiments show that the binary code created by applying the suggested method is of high quality.     

Bioequivalence revisited: non-parametric analysis of two-period cross-over studies

Hauschke et al.'s non-parametric bioequivalence procedure for treatment effects and some aspects of computer implementation, among them Meineke and De Hey's algorithm, are explored. For studies with up to sixty subjects, a table of indices of the ranked intersubject-intergroup mean ratios or differences is given, to establish non-parametric 90% confidence intervals. It is shown that non-parametric analysis is not limited to treatment effects: it can also be applied to period and sequence effects. This extended procedure can be seen as the non-parametric analogue of analysis of variance on two-period cross-over studies. A FORTRAN program (BIOQNEW) incorporating Meineke and De Mey's algorithm is presented. This program provides non-parametric point estimates for treatment and period effects, 90% and 95% confidence intervals for test-versus-reference treatments, the 95% confidence interval for periods and a test on sequence effects, so that it can also be used for other than bioequivalence studies. BIOEQNEW can handle ratios (‘multiplicative model’) as well as differences (‘additive model’). It optionally provides the complete non-parametric posterior probability distribution for treatment ratios or differences, so that Schuirmann's ‘two one-sided tests procedure’ can also be performed in a non-parametric way.     

NASAB: a finite element software for the nonlinear aerostatic stability analysis of cable-supported bridges

This paper presents the development and applications of the finite element software, NASAB, which can be used for linear, geometrically nonlinear, and materially nonlinear analyses of structure and nonlinear aerostatic stability analysis of cable-supported bridges. The software program consists of two main parts: a programming part and a computational part. The windows programming part written in FORTRAN90 was designed mainly to present the NASAB software in a user-friendly environment. The computational part was written in FORTRAN77. The use of FORTRAN77 is to effectively take advantage of existing codes, thus speeding up code design and implementation. The usefulness of FORTRAN programming language to develop a user-friendly interface including pre-processing and post-processing has been demonstrated by the present version of the software.     

GENMIX—A generalized petrological mixing model program

GENMIX is an interactive FORTRAN program to solve generalized petrological mixing models of the type, biotite + sillimanite + quartz = garnet + K-feldspar + water, as well as simple mixing models of the type, basalt = andesite + olivine + pyroxene. The driving program is designed for ease of use and provides facilities for printing, editing, changing and adding analyses or oxides to the data bank from which analyses are selected for use in the model. Analyses also can have Fe ratios changed, be recalculated to sum to 100 percent, or be restored to previous values. The program is suited ideally for teaching purposes, as it is impossible to crash by incorrect data input, due to innumerable error traps and all data being read as characters before being converted to numbers.     

基于数字孪生的火箭测试与发射过程健康管理技术研究

为了解决运载火箭对地面测试与发射过程中对数据综合分析能力,飞行过程的故障诊断和预测能力,以及故障处理措施的快速决策等能力的迫切需求,提出一种基于数字孪生技术的火箭测试与发射过程健康管理系统设计方案;该方案通过建立运载火箭测试与发射阶段数字孪生模型,实现对火箭测试和发射过程的天地镜像仿真,依托数字孪生模型,对运载火箭健康管理功能进行了设计和优化;利用真实火箭和数字孪生火箭的信息交互,可有效实现火箭测试过程数据分析、飞行过程协同诊断,以及故障处理决策支持等功能;该系统提高了火箭发射的可靠性,为火箭可靠飞行提供了技术保障;同时,该技术在运载火箭健康管理上的应用也面临一些关键技术还需要进一步突破和发展.     

C程序单元级依赖性分析

程序依赖性分析是软件分析的一个基本内容，目前的相关工作大多集中在语句级的分析方面。人们同样需要单元级的依赖信息来考察单元间的信息流向及整个程序的构架。本文针对C程序中函数间的调用依赖、参数传递依赖、全局数据依赖以及文件间的包含依赖和外部变量定义依赖进行了分析，并提出单元依赖图表达这些关系。基于此图，本文采用基于信息论的方法度量了单元间的耦合性。单元依赖图中保留的函数调用间的互斥关系提高了度量的准确性。相关的分析思想和技术适用于分析使用其它高级程序设计语言编写的软件。     

基于Fluent的双加热湿度传感器传热性能分析

双加热湿度传感器可实现大气湿度连续探测.液滴、冰晶等水凝物覆盖在双加热湿度传感器表面,容易导致其测量精度和响应速度降低.为了提高测量精度和响应速度,有必要对双加热湿度传感器进行除湿处理.采用Pro/E建立4种尺寸的双加热湿度传感器三维模型;利用ICEM CFD中模块化的方法对模型进行分网,得到了较高的网格质量,降低了计算时间,提高了计算精度;利用Fluent稳态分析模拟出2只湿度传感器不同间距下的相互影响情况,瞬态分析模拟出升温时间和降温时间特性.根据仿真结果,提出高空和低空2种模式加热策略.     

A Case for Compressing Traces with BDDs

Instruction-level traces are widely used for program and hardware analysis. However, program traces for just a few seconds of execution are enormous, up to several terabytes in size, uncompressed. Specialized compression can shrink traces to a few gigabytes, but trace analyzers typically stream the decompressed trace through the analysis engine. Thus, the complexity of analysis depends on the decompressed trace size (even though the decompressed trace is never stored to disk). This makes many global or interactive analyses infeasible. This paper presents a method to compress program traces using binary decision diagrams (BDDs). BDDs intrinsically support operations common to many desirable program analyses and these analyses operate directly on the BDD. Thus, they are often polynomial in the size of the compressed representation. The paper presents mechanisms to represent a variety of trace data using BDDs and shows that BDDs can store, in 1 GB of RAM, the entire data-dependence graph of traces with over 1 billion instructions. This allows rapid computation of global analyses such as heap-object liveness and dynamic slicing     

Plots for examination of univariate twin data.

We discuss informative plots for univariate twin data that can be used in conjunction with twin data analyses. The plots are useful for spotting outliers, spotting possible single gene effects, and displaying the contribution of individual twin pairs to the fit of genetic models of the data. We illustrate the use of the plots on bone mineral data, and present programs for generating the plots in SAS.     

Software for advanced HRV analysis

A computer program for advanced heart rate variability (HRV) analysis is presented. The program calculates all the commonly used time- and frequency-domain measures of HRV as well as the nonlinear Poincaré plot. In frequency-domain analysis parametric and nonparametric spectrum estimates are calculated. The program generates an informative printable report sheet which can be exported to various file formats including the portable document format (PDF). Results can also be saved as an ASCII file from which they can be imported to a spreadsheet program such as the Microsoft Excel. Together with a modern heart rate monitor capable of recording RR intervals this freely distributed program forms a complete low-cost HRV measuring and analysis system.