System of systems architecture（SoSA） has received increasing emphasis by scholars since Zachman ignited its flame in 1987. Given its complexity and abstractness, it is critical to validate and evaluate SoSA to ensur...System of systems architecture（SoSA） has received increasing emphasis by scholars since Zachman ignited its flame in 1987. Given its complexity and abstractness, it is critical to validate and evaluate SoSA to ensure requirements have been met.Multiple qualities are discussed in the literature of SoSA evaluation, while research on functionality is scarce. In order to assess SoSA functionality, an extended influence diagram（EID） is developed in this paper. Meanwhile, a simulation method is proposed to elicit the conditional probabilities in EID through designing and executing SoSA. An illustrative anti-missile architecture case is introduced for EID development, architecture design, and simulation.展开更多
SOZL (structured methodology + object-oriented methodology + Z language) is a language that attempts to integrate structured method, object-oriented method and formal method. The core of this language is predicate dat...SOZL (structured methodology + object-oriented methodology + Z language) is a language that attempts to integrate structured method, object-oriented method and formal method. The core of this language is predicate data flow diagram (PDFD). In order to eliminate the ambiguity of predicate data flow diagrams and their associated textual specifications, a formalization of the syntax and semantics of predicate data flow diagrams is necessary. In this paper we use Z notation to define an abstract syntax and the related structural constraints for the PDFD notation, and provide it with an axiomatic semantics based on the concept of data availability and functionality of predicate operation. Finally, an example is given to establish functionality consistent decomposition on hierarchical PDFD (HPDFD).展开更多
The interaction parameters for various phases in the Ti-W and Pd-W systems were calcula- ted using phase diagram information by means of a numerical procedure.The approach differs significantly from the trial and erro...The interaction parameters for various phases in the Ti-W and Pd-W systems were calcula- ted using phase diagram information by means of a numerical procedure.The approach differs significantly from the trial and error method and has the advantage of being very robust in the sense that one can make full use of the accurate experimental phase diagram data and deal with situations which are difficult or even impossible for the trial and error method. Using calculated parameters and lattice stability values for Ti,W and Pd given in literature, the diagrams of the above systems were recalcula- ted.The results are in good agreement with experimental information.展开更多
The forming limit diagram（FLD） is an important tool to be used when characterizing the formability of metallic sheets used in metal forming processes. Experimental measurement and determination of the FLD is timecon...The forming limit diagram（FLD） is an important tool to be used when characterizing the formability of metallic sheets used in metal forming processes. Experimental measurement and determination of the FLD is timeconsuming and therefore the analytical prediction based on theory of plasticity and instability criteria allows a direct and efficient methodology to obtain critical values at different loading paths, thus carrying significant practical importance.However, the accuracy of the plastic instability prediction is strongly dependent on the choice of the material constitutive model [1–3]. Particularly for materials with hexagonal close packed（HCP） crystallographic structure, they have a very limited number of active slip systems at room temperature and demonstrate a strong asymmetry between yielding in tension and compression [4, 5]. Not only the magnitude of the yield locus changes, but also the shape of the yield surface is evolving during the plastic deformation [4]. Conventional phenomenological constitutive models of plasticity fail to capture this unconventional mechanical behavior [4, 6]. Cazacu and Plunkett [6] have proposed generic yield criteria, by using the transformed principal stress, to account for the initial plastic anisotropy and strength differential（SD） effect simultaneously. In this contribution, a generic FLD MATLAB script was developed based on Marciniak–Kuczynski analytical theory and applied to predict the localized necking. The influence of asymmetrical effect on the FLD was evaluated. Several yield functions such as von Mises, Hill, Barlat89, and Cazacu06 were incorporated into analysis. The paper also presents and discusses the influence of different hardening laws on the formability of materials with HCP crystal structures. The findings indicate that the plastic instability theory coupled with Cazacu model can adequately predict the onset of localized necking for HCP materials under different strain paths.展开更多
目的:探讨时效性激励模式联合阶梯图式康复训练对慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者心肺功能及生活质量的影响。方法:选取2021年1月—2023年12月北京华信医院收治的102例COPD患者作为研究对象,按照随...目的:探讨时效性激励模式联合阶梯图式康复训练对慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者心肺功能及生活质量的影响。方法:选取2021年1月—2023年12月北京华信医院收治的102例COPD患者作为研究对象,按照随机数表法分为对照组和研究组,各51例。对照组接受常规康复训练,研究组在对照组基础上实施时效性激励模式联合阶梯图式康复训练,两组均进行12周的干预训练。比较两组心肺功能[第1秒用力呼气容积(forced expiratory volume in first second,FEV_(1))、FEV_(1)/用力肺活量(forced vital capacity,FVC)、6分钟步行试验、圣乔治呼吸问卷(St.Georges respiratory questionnaire,SGRQ)]及生活质量[健康调查简表(the MOS item short form health survey,SF-36)]。结果:干预前,两组心肺功能及生活质量比较,差异无统计学意义(P>0.05);干预后,两组FEV_(1)、FEV_(1)/FVC、SF-36评分较干预前升高,且研究组高于对照组,差异有统计学意义(P<0.05);干预后,两组SGRQ评分较干预前降低,且研究组低于对照组,差异有统计学意义(P<0.05);干预后,两组6分钟步行试验距离较干预前增加,且研究组长于对照组,差异有统计学意义(P<0.05)。结论:时效性激励模式联合阶梯图式康复训练可有效提高COPD患者的心肺功能,改善生活能力。展开更多
基金supported by the National Natural Science Foundation of China(71571189)
文摘System of systems architecture（SoSA） has received increasing emphasis by scholars since Zachman ignited its flame in 1987. Given its complexity and abstractness, it is critical to validate and evaluate SoSA to ensure requirements have been met.Multiple qualities are discussed in the literature of SoSA evaluation, while research on functionality is scarce. In order to assess SoSA functionality, an extended influence diagram（EID） is developed in this paper. Meanwhile, a simulation method is proposed to elicit the conditional probabilities in EID through designing and executing SoSA. An illustrative anti-missile architecture case is introduced for EID development, architecture design, and simulation.
文摘SOZL (structured methodology + object-oriented methodology + Z language) is a language that attempts to integrate structured method, object-oriented method and formal method. The core of this language is predicate data flow diagram (PDFD). In order to eliminate the ambiguity of predicate data flow diagrams and their associated textual specifications, a formalization of the syntax and semantics of predicate data flow diagrams is necessary. In this paper we use Z notation to define an abstract syntax and the related structural constraints for the PDFD notation, and provide it with an axiomatic semantics based on the concept of data availability and functionality of predicate operation. Finally, an example is given to establish functionality consistent decomposition on hierarchical PDFD (HPDFD).
文摘The interaction parameters for various phases in the Ti-W and Pd-W systems were calcula- ted using phase diagram information by means of a numerical procedure.The approach differs significantly from the trial and error method and has the advantage of being very robust in the sense that one can make full use of the accurate experimental phase diagram data and deal with situations which are difficult or even impossible for the trial and error method. Using calculated parameters and lattice stability values for Ti,W and Pd given in literature, the diagrams of the above systems were recalcula- ted.The results are in good agreement with experimental information.
基金support from the Portuguese Foundation for Science and Technology (FCT) via the projects PTDC/EMS-TEC/2404/2012, and PTDC/EMS-TEC/1805/2012FEDER funds through the program COMPETE-‘‘Programa Operacional Factores de Competitividade’’ is greatly acknowledged
文摘The forming limit diagram（FLD） is an important tool to be used when characterizing the formability of metallic sheets used in metal forming processes. Experimental measurement and determination of the FLD is timeconsuming and therefore the analytical prediction based on theory of plasticity and instability criteria allows a direct and efficient methodology to obtain critical values at different loading paths, thus carrying significant practical importance.However, the accuracy of the plastic instability prediction is strongly dependent on the choice of the material constitutive model [1–3]. Particularly for materials with hexagonal close packed（HCP） crystallographic structure, they have a very limited number of active slip systems at room temperature and demonstrate a strong asymmetry between yielding in tension and compression [4, 5]. Not only the magnitude of the yield locus changes, but also the shape of the yield surface is evolving during the plastic deformation [4]. Conventional phenomenological constitutive models of plasticity fail to capture this unconventional mechanical behavior [4, 6]. Cazacu and Plunkett [6] have proposed generic yield criteria, by using the transformed principal stress, to account for the initial plastic anisotropy and strength differential（SD） effect simultaneously. In this contribution, a generic FLD MATLAB script was developed based on Marciniak–Kuczynski analytical theory and applied to predict the localized necking. The influence of asymmetrical effect on the FLD was evaluated. Several yield functions such as von Mises, Hill, Barlat89, and Cazacu06 were incorporated into analysis. The paper also presents and discusses the influence of different hardening laws on the formability of materials with HCP crystal structures. The findings indicate that the plastic instability theory coupled with Cazacu model can adequately predict the onset of localized necking for HCP materials under different strain paths.
文摘目的:探讨时效性激励模式联合阶梯图式康复训练对慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者心肺功能及生活质量的影响。方法:选取2021年1月—2023年12月北京华信医院收治的102例COPD患者作为研究对象,按照随机数表法分为对照组和研究组,各51例。对照组接受常规康复训练,研究组在对照组基础上实施时效性激励模式联合阶梯图式康复训练,两组均进行12周的干预训练。比较两组心肺功能[第1秒用力呼气容积(forced expiratory volume in first second,FEV_(1))、FEV_(1)/用力肺活量(forced vital capacity,FVC)、6分钟步行试验、圣乔治呼吸问卷(St.Georges respiratory questionnaire,SGRQ)]及生活质量[健康调查简表(the MOS item short form health survey,SF-36)]。结果:干预前,两组心肺功能及生活质量比较,差异无统计学意义(P>0.05);干预后,两组FEV_(1)、FEV_(1)/FVC、SF-36评分较干预前升高,且研究组高于对照组,差异有统计学意义(P<0.05);干预后,两组SGRQ评分较干预前降低,且研究组低于对照组,差异有统计学意义(P<0.05);干预后,两组6分钟步行试验距离较干预前增加,且研究组长于对照组,差异有统计学意义(P<0.05)。结论:时效性激励模式联合阶梯图式康复训练可有效提高COPD患者的心肺功能,改善生活能力。
