Error Propagation in Implicit Pseudodynamic Testing of Nonlinear Systems

Error propagation analysis of an implicit pseudodynamic algorithm has been developed for linear elastic systems. However, these error propagation results might not be applicable to nonlinear systems. Since the pseudodynamic testing method aims at investigating the nonlinear behavior of a seismically loaded structure it is important to perform the error propagation analysis of the implicit pseudodynamic algorithm for nonlinear systems. A technique to conduct the nonlinear error propagation analysis of an implicit pseudodynamic algorithm is constructed and is illustrated by analyzing the constant average acceleration method. Theoretical results reveal that the numerical and error propagation properties for nonlinear systems are generally inherited from those of linear elastic systems although some properties are affected by the step degree of nonlinearity. It is verified that the most important property of unconditional stability is preserved for nonlinear systems for a complete pseudodynamic test procedure even if the convergence error is present. It is concluded that error propagation for the improved implementation is superior to that of the direct implementation and is consistent with that developed for linear elastic systems.     

Maori cultural identity and the New Zealand search for nationhood

The imaging techniques used to follow-up patients submitted to surgery for colorectal cancers are presented as are their advantages and disadvantages. The sensitivity of ultrasonography (US) for postoperative surveillance of the liver varies considerably according to whether the absence or presence of metastases is sought (83%) or their exact number (53-82%). US is recommended by French clinicians as the standard follow-up examination whereas, American clinicians tend to discuss CT-Scan or MRI for the same purpose. Some authors advocate Doppler ultrasonography for the detection of liver metastases. Spiral CT-Scan offers better results than conventional CT and is now considered second in rank to US for follow-up studies. Its sensitivity exceeds 90% for metastases greater than 1 cm. IRM and arterial CT-scan are not applicable for follow-up but are sometimes indicated for difficult cases before hepatectomy. US is also an appropriate technique for postoperative exploration of the abdominal cavity. When the CEA level and the US examination are normal, this technique is sufficient. However, in dubious clinical or biological cases, US should be associated with a spiral CT-Scan. Most clinicians recommend a reference CT-Scan, two to four months after the resection and every 6 months for 2 years and then annually. The same follow-up strategy is advocated after abdominoperineal resection and for surveillance of the pelvis. The sensitivity of CT-Scan is between 69 and 88% but it is unable to differentiate recurrence from fibrosis. IRM, with a sensitivity of 90%, is the best method for overcoming with problems related to the differential diagnosis and particularly novel fast acquisition imaging and contrast agents. Ultrasonoendoscopy, repeated every 4 to 6 months after anterior resection, is also a useful examination for surveillance of the pelvis. PET-Scan has produced encouraging results for the detection of metastases and for the differential diagnosis between local recurrence and fibrosis. When available, this technique could become the "gold standard" for the surveillance of patients following surgery for colorectal cancers.     

Genotoxicity of hydrazino-phtalazine antihypertensive drugs assessed by an in vitro micronucleus assay

Oral anticoagulant therapy is effective antithrombotic treatment for several indications. The results of prothrombin time monitoring should be reported as the International Normalized Ratio (INR). An INR of 2 to 3 is the recommended therapeutic range for all indications except for the prevention of systemic embolism in patients with mechanical heart valves and for the long-term treatment of patients with myocardial infarction, for whom an INR range of 2.5 to 3.5 is recommended. Oral anticoagulant therapy with warfarin sodium is the preferred approach for preventing stroke in most patients with atrial fibrillation. The available data suggest that warfarin is more effective than aspirin. Aspirin, 325 mg/d, is indicated for patients in whom warfarin is contraindicated or in patients less than 75 years of age who are at low risk for stroke because risk factors are absent. In patients 75 years of age or more, close monitoring of warfarin treatment is prudent to avoid major bleeding due to poor anticoagulant control. In selected patients, patient-self-monitoring and adjustment of warfarin treatment using a portable prothrombin time monitor may be effective and safe.     

Boundary friction for thermoelastic martensitic transformations

This paper is mainly to discuss the free energy, phase boundary friction and reversibility for thermoelastic martensitic transformations. A method is suggested to obtain, quantitatively, the energy consumed for boundary friction. The base for this calculation is the phenomenological theory suggested by authors before. Applications and results of the method for different data are studied. Comparison of this method with that of Ortin and Planes is discussed. The basic viewpoint in this paper is that the energy consumed for boundary friction converts totally into irreversible heat. This is different from the “entropy argument” of Ortin and Planes. The base of this argument is also reviewed.     

小型凝汽式汽轮发电机组低真空供热技术研究

文章介绍了小型凝汽式汽轮发电机组低真空供热工艺发行的基本方法,即通过降低机组真空度提高排汽温度,加热循环水用于采暖,并以包钢4#发电机为例进行了经济效益和环境效益分析。针对系统发行时应注意问题提出了相应的对策,为同类机组父权真空供热发行提供了借鉴和参考。该技术具有良好的发展空间和推广前景。     

Clinical applicability of an enzyme micromethod for the rapid determination of blood sugar

The clinical applicability of an enzymatic micromethod for the fast determination of glycaemia is discussed. The method is based on the use of an optical reflectometer for the quantitative reading of the variation in colour intensity of specific reactive strips for the semi-quantitative evaluation of blood glucose. Thanks to the method's rapidity and simplicity, it can be used for mass screening and is also very useful for the routine investigations of Diabetologic Centres. It is also invaluable for the identification of emergency clinical situations.     

Transient Dynamic Nonlinear Analysis Using MIMD Computer Architectures

This paper presents research on the use of homogeneous parallel and heterogeneous distributed computers for finite-element analysis of transient dynamic problems using a message passing interface. The appropriate computer architectures are discussed, and this review is the basis for the development of a new definition of computational efficiency for heterogeneously distributed finite-element analysis. A code for the transient nonlinear analysis of reinforced concrete plates is profiled. It is demonstrated that although the code is efficient for homogeneous computing systems a new message passing procedure must be developed for heterogeneously distributed systems. A new algorithm is developed and tested on a heterogeneous system of workstations.     

基于APDL的轧机辊系变形仿真研究

辊系的弹性变形会直接影响到板形,它是板形研究的核心问题。开发了一种轧机参数化有限元仿真软件,利用VB软件进行可视化编程,提供一个友好的人机交互界面,VB后台调用ANSYS软件进行辊系变形的有限元仿真。软件通用性强,操作简单灵活,并根据工程需要提出了若干软件升级的技术方案。     

Issues for covariance analysis of dichotomous and ordered categorical data from randomized clinical trials and non-parametric strategies for addressing them

Analysis of covariance is an effective method for addressing two considerations for randomized clinical trials. One is reduction of variance for estimates of treatment effects and thereby the production of narrower confidence intervals and more powerful statistical tests. The other is the clarification of the magnitude of treatment effects through adjustment of corresponding estimates for any random imbalances between the treatment groups with respect to the covariables. The statistical basis of covariance analysis can be either non-parametric, with reliance only on the randomization in the study design, or parametric through a statistical model for a postulated sampling process. For non-parametric methods, there are no formal assumptions for how a response variable is related to the covariables, but strong correlation between response and covariables is necessary for variance reduction. Computations for these methods are straightforward through the application of weighted least squares to fit linear models to the differences between treatment groups for the means of the response variable and the covariables jointly with a specification that has null values for the differences that correspond to the covariables. Moreover, such analysis is similarly applicable to dichotomous indicators, ranks or integers for ordered categories, and continuous measurements. Since non-parametric covariance analysis can have many forms, the ones which are planned for a clinical trial need careful specification in its protocol. A limitation of non-parametric analysis is that it does not directly address the magnitude of treatment effects within subgroups based on the covariables or the homogeneity of such effects. For this purpose, a statistical model is needed. When the response criterion is dichotomous or has ordered categories, such a model may have a non-linear nature which determines how covariance adjustment modifies results for treatment effects. Insight concerning such modifications can be gained through their evaluation relative to non-parametric counterparts. Such evaluation usually indicates that alternative ways to compare treatments for a response criterion with adjustment for a set of covariables mutually support the same conclusion about the strength of treatment effects. This robustness is noteworthy since the alternative methods for covariance analysis have substantially different rationales and assumptions. Since findings can differ in important ways across alternative choices for covariables (as opposed to methods for covariance adjustment), the critical consideration for studies with covariance analyses planned as the primary method for comparing treatments is the specification of the covariables in the protocol (or in an amendment or formal plan prior to any unmasking of the study.     

A dose-response study of anorectic drug effects on food intake, self-stimulation, and stimulation-escape

The DNA polymerase of Ustilago maydis is stimulated by a DNA binding protein from the same organism. Analysis of this stimulation shows that there is an increase in affinity for both substrates of the reaction. The apparent Km for deoxynucleoside triphosphates is decreased 3 fold, and that for denatured DNA by 4 fold. In both cases the maximum velocity (Vmax) is increased 1.2 to 1.4 fold. It is suggested that the variability in the affinity of the enzyme for deoxynucleoside triphosphates mediated by the binding protein may provide the basis for the UV sensitivity of pyrimidine auxotrophs in this organism.     

Function of DnaA protein, the initiator for chromosomal DNA replication in E. coli]

DnaA protein is an initiator for chromosomal DNA replication in E. coli. We have examined the function of the protein to answer the following four questions; 1. How DnaA protein is inactivated after DNA replication for the suppression of re-initiation? 2. How DnaA protein is activated for the initiation of DNA replication? 3. Does DnaA protein have functions other than that for DNA replication? 4. Is DnaA protein is a good target for new antibiotics? In this review, I summarize our recent studies for these questions.     

Skin closures using cyanoacrylate tissue adhesives. Plastic Surgery Educational Foundation DATA Committee. Device and Technique Assessment

Studies have been done and approval is soon possible from the FDA for an octylcyanoacrylate tissue glue for closure of lacerations of incisions. This is a newer-generation cyanoacrylate that improves on the butylcyanoacrylates currently in use in Canada and other countries but not approved by the FDA. It is a pliable, waterproof, film adhesive that can be applied to a laceration and left in place until it disintegrates in 7 to 14 days. It is safe and effective and represents an improvement over the butylcyanoacrylates that have been used for years in many countries. It is not a replacement for sutures but does offer an alternative. Some indications that seem appropriate are for closure of incisions that would be under casts; for simple lacerations in children to avoid the fear of suturing and suture removal; and for closure of incisions or lacerations where it would be a problem for a follow-up visit. This adhesive is less indicated for closure over highly mobile areas such as joints; for areas with usage and friction such as hands or feet; or for areas where exact alignment is a priority, such as the face or eyelids.     

Role of microstructure and residual stresses on fatigue crack initiation of carbonitrided steels

In this paper the role of microstructure and residual stresses on fatigue crack initiation of gaseous carbonitrided steels is examined. Optimum for austenite content in the case is investigated for microstructures containing bainite and for those without bainite. Fractographic study suggests subsurface initiation sites for notched specimens when austenite content is high and initiation sites at the surface when austenite is low.     

Diagnostic framework of nonpalpable lesions of the breast

Mammography is the most sensitive test for non-palpable lesions, but its specificity is quite limited. When a decision for biopsy is based only on the mammographic appearance the benign/malignant biopsy ratio (B/M) is around 3:1. The B/M varies according to the radiological pattern being favourable for stellate opacities, high for regular opacities, and intermediate for distortions and microcalcifications. Aspiration cytology of non-palpable lesions, either sonographically or stereotaxically guided, is highly accurate. When the decision for surgical biopsy is taken also on the basis of cytology, B/M may be reduced by up to 0.5:1. As false negatives are expected for cytology, lesions which are strongly suspicious at mammography must be biopsied anyway. Sonography guided aspiration is possible in about a half of mammographically detected non-palpable lesions, particularly for opacities, whereas distortions and microcalcification are seldom visualized at sonography. Cytology should be routinely performed in the presence of questionable non-palpable lesions.     

Using a Small Ring and a Fall-Cone to Determine the Plastic Limit

The plastic limit is an important property of fine-grained soils. The standard thread-rolling method for determining the plastic limit has long been criticized for requiring considerable judgements from the operator. This paper presents the design of a small specimen ring for fall-cone tests for determining the plastic limit. A small specimen ring of 20 mm in diameter and 20 mm in depth is designed and used for cone penetrations between 10 and 3 mm. For each soil tested, a linear relationship between the logarithmic cone penetration and the logarithmic water content is obtained by a regression analysis on four data points. This linear relationship is extended to determine the plastic limit at 2 mm of cone penetration. The fall-cone plastic limits of 21 soils are in good agreement with their thread-rolling plastic limits. In addition, a one-point fall-cone method is also recommended for determining the plastic limit. As the fall-cone has been recommended in several standards for determining the liquid limit, it is preferable that it is also used for determining the plastic limit.     

The appropriate use of null hypothesis testing.

The many criticisms of null hypothesis testing suggest when it is not useful and what it should not be used for. This article explores when and why its use is appropriate. Null hypothesis testing is insufficient when size of effect is important, but it is ideal for testing ordinal claims relating the order of conditions, which are common in psychology. Null hypothesis testing also is insufficient for determining beliefs, but it is ideal for demonstrating sufficient evidential strength to support an ordinal claim, with sufficient evidence being 1 criterion for a finding entering the corpus of legitimate findings in psychology. The line between sufficient and insufficient evidence is currently set at p     

Slag Melting Characteristic of Slag Forming and Slag Splashing for BOF Less Slag Smelting

 The slag melting characteristic of slag forming and slag splashing for 300 t BOF less slag process is researched by combining the methods of the slag chemical composition, the melting point determination and the petrographic analysis. The results show that the melting point of final slag for less slag smelting is 20 ℃ lower than that for conventional smelting. According to results of the petrographic analysis, the C3S (3CaO·SiO2) and C2S (2CaO·SiO2) content for less slag smelting are lower than those for conventional smelting, while the RO (FeO, MgO, MnO, etc) phase and C4AF (4CaO·Al2O3·Fe2O3) phase are higher than those for conventional smelting. According to results of the chemical analysis, the (CaO) content and slag basicity for less slag smelting are higher than those for conventional smelting, while (FeO) and (MgO) content in slag for less slag smelting are almost equal to those for conventional smelting. The reason why slag melting point for less slag smelting is lower than that for conventional smelting is that the quantity of added fluorite for less slag smelting is more than that for conventional smelting. According to the analysis results the slag melting point is determined by the C3S, C2S, RO phase and C4AF content. According to the results of slag melting characteristic before and after slag splashing for less slag smelting, the present adjusting slag process has little effect. It is important to adjust the composition of BOF final slag. The (FeO) content in slag is to be reduced at the slag splashing and adjusting slag process for less slag smelting.     

Mix-Mode Elastic Finite Element Formulation for Bonded Granular Material Considering Rotation of Particles

Rotation of particles in granular material is an important mechanism, which is responsible for the distinct feature of moment transfer within granular material. A couple-stress continuum is adopted to model such effect. The paper presents a mix-mode finite element formulation for the analysis of a couple stress continuum. A modified variational formulation is proposed to render unconditional convergence. The developed finite element method is validated by comparing the computed results with closed-form solutions. In order to verify whether the couple-stress continuum is appropriate for modeling granular media, finite element results for two different boundary value problems are performed and compared with that obtained from discrete analysis. Physical meaning of internal length, a new parameter of the material, is discussed. The suitability of the couple-stress continuum for modeling granular medium is evaluated.     

一次成型四层卷焊管成型过程中的稳定性研究

首先从力学的角度推导了周边受非均布载荷作用的矩形平板稳定性的基本微分方程式,进而得出了沿X方向的相对侧面受均布压力、Y方向的相对侧面受均布牵引力作用的周边自由支撑的矩形平板的稳定性计算所必须的压力强度极限计算公式。在研究了四层卷焊管成型特点的基础上,建立了卷焊管成型稳定性计算的力学和数学模型,进而对十架四层卷焊管成型进行了稳定性分析计算。     

Section Properties for Latticed Members of San Francisco–Oakland Bay Bridge

This paper focuses on the determination of section properties of latticed members for seismic retrofit of the San Francisco–Oakland Bay Bridge. To consider actual section integrity for a latticed member, the concept of reduction factors βm for moment of inertia and βt for torsional constant is introduced to account for the shear flow transferring capacity of lacing bars or battens and their connections. A set of formulas is proposed for calculating section properties required for seismic analysis and capacity determination. The validity of the proposed section properties is confirmed by a finite-element analysis of a latticed member. It is found that the proposed simple procedure closely resembles the finite-element analysis results. The proposed method is also supported by the recent 1∕2 scale model test of the SFOBB laced member at UNR.