用于分布式并行数据库系统的重定向算法

分布式并行数据库系统以高可用性、高效率等特征愈来愈受到人们的关注。针对分布式并行数据库系统的特征,提出了分布式并行重定向算法,实现服务器节点的透明切换。该算法不仅能实现负载均衡以及位置透明性,提高系统效率,而且能保证节点故障时事务不被中断,实现系统的高可用性。

On reducibility of a class of nonlinear quasi-periodic systems with small perturbational parameters near equilibrium

Consider the reducibility of a class of nonlinear quasi-periodic systems with multiple eigenvalues under perturbational hypothesis in the neighborhood of equilibrium. That is, consider the following system x = （A ＋ εQ（ t） ）x ＋ eg（t） ＋ h（x, t）, where A is a constant matrix with multiple eigenvalues; h = O（x2） （x-4）） ; and h（x, t）, Q（t）, and g（t） are analytic quasi-periodic with respect to t with the same frequencies. Under suitable hypotheses of non-resonance conditions and non-degeneracy conditions, for most sufficiently small ε, the system can be reducible to a nonlinear quasi-periodic system with an equilibrium point by means of a quasi-periodic transformation.

Single-machine scheduling with preventive periodic maintenance and resumable jobs in remanufacturing system

A single-machine scheduling with preventive periodic maintenance activities in a remanufacturing system including resumable and non-resumable jobs is studied.The objective is to find a schedule to minimize the makespan and an LPT-LS algorithm is proposed.Non-resumable jobs are first scheduled in a machine by the longest processing time（LPT） rule,and then resumable jobs are scheduled by the list scheduling（LS） rule.And the worst-case ratios of this algorithm in three different cases in terms of the value of the total processing time of the resumable jobs（denoted as S2） are discussed.When S2 is longer than the spare time of the machine after the non-resumable jobs are assigned by the LPT rule,it is equal to 1.When S2 falls in between the spare time of the machine by the LPT rule and the optimal schedule rule,it is less than 2.When S2 is less than the spare time of the machine by the optimal schedule rule,it is less than 2.Finally,numerical examples are presented for verification.

Quadratic integrability of solutions based on a class of delayed systems

Some properties such as oscillation, stability, existence of periodic solutions and quadratic integrability of solutions based on a class of second order nonlinear delayed systems are analyzed by using the V-function, the Lyapunov functional or the Beuman-Bihari inequality, and some sufficient conditions based on those properties are given. Finally, the conclusions are applied to over-voltage models based on three-phase nonsynchronous closing of switches appearing in the power systems, the results in accord with the background physical meaning are obtained. And all the conditions of the conclusions are easy to validate, so the conclusions have definite theoretical meaning and are easy to apply in practice.

Prediction of the Hualian Earthquakes in Taiwan and an Extended Discussion on the Method of Commensurability

The method of commensurability was used by the authors to predict the great earthquake of magnitude 7.5 that occurred on March 31,2002 in Taiwan 70km away from Hualian. Analyzing the earthquakes of magnitude≥7.0 which occurred in the Hualian area of Taiwan within the 20th century, the authors discovered that the occurrences of the earthquakes are commensurable. The earthquakes of magnitude 7.6 which occurred in Hualian of Taiwan, on September 20th, 1999 and of magnitude 7.5 which occurred 70 km away from Hualian, on March 31th, 2002 appeared at the commensurable point of K=2 and the period times the golden section, respectively. An extended discussion is carried out on the method of commensurability and its implied physical significance, especially on the contribution of the commensurable periodic extension made by Prof. Weng Wenbo.

A quantitative method for sustainable product development

A quantitative measure-based method for the design and evaluation of sustainable products is proposed. The method uses multi-criteria in product design to meet sustainable requirements from qualitative criteria to quantitative metrics. The method integrates quality function deployment concepts with the life cycle assessment to establish a quantitative method for sustainable product development. It considers both customer needs and sustainable requirements by mapping these needs into design details using the axiomatic design and benchmarking methods. The method is applied in the wheelchair design. Four popular wheelchairs in the market are selected as benchmarks and are rated based on customer needs and sustainable criteria. The design matrix identifies the relationship of functional requirements and design parameters of the wheelchair. Compared to the best benchmark product, the proposed wheelchair can reduce costs by 13.8%, environment footprints 18.55%, mass 4.5%, and components 2.2%.

Cyclic Variability in Chemical Composition and Swelling-Shrinkage Properties of the Xiashu Loess Stratum near Nanjing,China

Xiashu loess strata are widely distributed along the middle-lower reaches of the Yangtze River in East China with the stratum near Nanjing,Jiangsu Province being typical.The cyclic variability of the stratum was investigated through comparison of geological features,chemical composition,and swelling-shrinkage properties between the loess and the paleosol layers.Based on the investigation of such a cyclic variability,soil behavior associated with the unsaturated state of the Xiashu loess stratum and its usefulness for geotechnical design and construction in the Nanjing area was analyzed. The stratum consisted of two types of cyclically alternating soil layers,namely the loess and the paleosol layers,which was the major cause for its cyclic variability.The loess and the paleosol layers were formed in different sedimentary environments.In order to avoid detrimental results from the differential engineering properties between them,this study suggested for the practitioners the importance of inspecting the variation of water content and controlling the downward net fluxes during geotechnical construction in the Nanjing area.

SERUM SOLUBLE E—CADHERIN LEVEL IN PATIENTS WITH ENDOMETRIOSIS

Objective.To investigate the serum sE cadherin level in patients with endometriosis and the alterations of that level in healthy control during the menstrual cycle.Methods.Thirty two patients with endometriosis and 30 healthy women were tested for serum sE cadherin levels by enzyme linked immunosorbent assay.Results.The serum sE cadherin levels in healthy control did not vary throughout the menstrual cycle,which were lower than those in patients with endometriosis.Conclusions.E cadherin might be involved in endometrial shedding during menstruation in endometriosis patients.The serum sE cadherin assay might be helpful as a serum marker for the diagnosis and management of endometriosis.

Estimating the Predictability of the Quasi-Biweekly Oscillation Using the Nonlinear Local Lyapunov Exponent Approach

The quasi-biweekly oscillation (QBWO) is a major intraseasonal variability (ISV) in the tropics. Based on bandpass-filtered outgoing longwave radiation (OLR) and wind field data, the predictability limits of the QBWO in boreal summer and boreal winter are investigated using the nonlinear local Lyapunov exponent (NLLE) approach The analysis shows that the evolution of the mean error growth of the QBWO in boreal summer and the evolution of the mean error growth in boreal winter are comparable Both curves exhibit rapid growth in the initial stage followed by a slowly fluctuating, ascending trend before saturation is reached. As a result, the potential predictability limits for the boreal summer QBWO are very close to those for the boreal winter QBWO, with a lead time of approximately three weeks. Given the current limitations in the simulation and prediction of ISV, including the QBWO, the results of this study provide a useful reference for assessing the predictability of the QBWO using model simulations.

Life prediction and test period optimization research based on small sample reliability test of hydraulic pumps

Hydraulic pumps belong to reliable long-life hydraulic components. The reliability evaluation includes characters such as long test period,high cost,and high power loss and so on. Based on the principle of energy-saving and power recovery,a small sample hydraulic pump reliability test rig is built,and the service life of hydraulic pump is predicted,and then the sampling period of reliability test is optimized. On the basis of considering the performance degradation mechanism of hydraulic pump,the feature information of degradation distribution of hydraulic pump volumetric efficiency during the test is collected,so an optimal degradation path model of feature information is selected from the aspect of fitting accuracy,and pseudo life data are obtained. Then a small sample reliability test of period constrained optimization search strategy for hydraulic pump is constructed to solve the optimization problem of the test sampling period and tightening end threshold,and it is verified that the accuracy of the minimum sampling period by the non-parametric hypothes is tested. Simulation result shows it could possess instructional significance and referenced value for hydraulic pump reliability life evaluation and the test's research and design.

Theoretical study of phase-matching properties for tunable terahertz-wave generation in isotropic nonlinear crystals

Theoretical investigation of the phase-matching properties for the tunable coherent terahertz wave generation in the isotro- pic semiconductor nonlinear materials of CdTe and GaP is presented according to their optical dispersion properties, based on a pulsed dual-wavelength KTP-OPO operating near degenerate point in the process of the difference frequency mixing. The cross-Reststrahlen band dispersion compensation phase-matching technique involved in this interaction is introduced concisely. The optimum lengths of DFG crystals are decided according to the minimum coherence lengths of the crystals in the given pump wavelength ranges. The results of analysis and calculation provide the useful and necessary theoretical basis and guidance for the future experiments.

Analysis of Sustainability Based on Life Cycle Assessment： An Empirical Study of Wine Production

The environmental planning and the current policy initiatives in European Union are aimed at continuous improvement of the productive fabric, heading toward a system in which the ＂quality＂ of products will no longer regardless of their environmental impacts. In this context, the methodology of LCA （life cycle assessment） is certainly one of the most innovative methods in the field of environmental protection as it allows evaluating the environmental burdens associated with a product, process or activity by identifying and quantifying material and energy consumption and environmental emissions. The objectives focus on finding the main impacts of the wine life cycle, as well as identifying crucial activities/stages in the wine production which establish the largest impacts. This paper＇s objective is to expose the advantages resulting from the use of the LCA method in the wine production sector, with a specific application to wine production in the Tuscany region.

Periodic Solutions for Two Coupled Nonlinear-Partial Differential Equations

In this paper, by applying the Jacobi elliptic function expansion method, the periodic solutions for two coupled nonlinear partial differential equations are obtained.

Using Long-Period Body Wave to Inverse Moment Tensors of the M_S6.8 Jiashi,Xinjiang Earthquake in 2003 and the Moderate and Small Earthquakes before and after It

An M_S6.8 strong earthquake took place in Jiashi,Xinjiang on February 24 of 2003.The digital wave form data recorded in Kashi and Wushi stations are selected to inverse the moment tensor solutions for the strong earthquake and the moderate and small earthquakes before and after it(108 earthquakes in 2001～2004).67 focal mechanism solutions have been calculated,and the results agree with those from Harvard University and USGS.The analysis reveals that before the strong earthquake,the moderate and small earthquake distribution was dispersed,and after the event the distribution was mainly concentrated around the strong earthquake.Before the strong earthquake,the seismic faults of the mid and small events had the character of strike-slip and normal faulting,and after the event,they exhibit strike-slip and thrust faulting.The region is dominated by near-NS horizontal compression from the southern block after the strong earthquake.

Amman＇s Land Typology： The Importance of Site Characteristics on the Delivery of Sustainable Buildings

Amman＇s land typology is characterized by hilly slopes, and this presents challenges and opportunities for architects and designers aiming at delivering sustainable buildings. The research focuses on the importance of any site＇s given criteria, mainly its slope and topography on the delivery of sustainable buildings. Amman city consists broadly of two main types of buildings, apartment buildings and villas, by studying each type of building with regard to its environmental context on a given site in the city, the research seeks to identify the sustainable variables that site topography delimit or facilitate, using a set of attributes for each building type. The main objective of this research is to highlight the sustainable approach for building on sloped sites throughout the building project life-cycle in general, and to set a sustainability framework for designers during the initial design phase in particular. A number of case studies for both types of buildings are studied and analysed, and conclusions are given based on syntheses of available data from literature review or case analysis. At the end, the research provides a mechanism for the development of guidelines for sustainable and passive viability on preferred buildings orientation in hilly areas with regard to local climatic data.

Revealing the Invisible： A New Approach for Enhancing Industrial Safety, Reliability and Remaining Life Assessment

Today＇s industry requires more reliable information on the current status of their hard assets; prognosis for continued usability of systems and better predictability of equipment life cycle maintenance. Therefore, an innovative technique for early detection of potential failure and condition monitoring is urgently required by many engineers. This document describes a novel approach to improve industrial equipment safety, reliability and life cycle management. A new field portable instrument called the ＂IMS （indicator of mechanical stresses）＂ utilizes magneto-anisotropic （＂cross＂） transducers to measure anisotropy of magnetic properties in ferromagnetic material. Mechanical stresses including residual stresses in Ferro-magnetic parts, are ＂not visible＂ to most traditional NDT （non-destructive testing） methods; for example, radiography and ultrasonic inspection. Stress build-up can be the first indicator that something is faulty with a structure. This can be the result of a manufacturing defect; or as assets age and fatigue, stress loads can become unevenly distributed throughout the metal. We outline the evaluation of IMS as a fast screening tool to provide structural condition or deterioration feedback in novel applications for pipelines, petrochemical refinery, cranes, and municipal infrastructure.

Impact of type 2 diabetes on the plasma levels of vascular endothelial growth factor and its soluble receptors type 1 and type 2 in patients with peripheral arterial disease

Objective： Type 2 diabetes coexistent with lower extremity artery disease （peripheral arterial disease （PAD）） can be observed in numerous patients. The mechanism compensating for ischemia and contributing to healing is angiogenesis-the process of forming new blood vessels. The purpose of this study was to assess the likely impact of type 2 diabetes on the plasma levels of proangiogenic factor （vascular endothelial growth factor A （VEGF-A）） and angiogenesis inhibitors （soluble VEGF receptors type 1 and type 2 （sVEGFR-1 and sVEGFR-2）） in patients with PAD. Methods： Among 46 patients with PAD under pharmacological therapy （non-invasive）, we identified, based on medical history, a subgroup with coexistent type 2 diabetes （PAD-DM2＋, n=15） and without diabetes （PAD-DM2-, n=31）. The control group consisted of 30 healthy subjects. Plasma levels of VEGF-A, sVEGFR-1, and sVEGFR-2 were measured using the enzyme-linked immunosorbent assay （ELISA） method. Results： The subgroups of PAD-DM2＋ and PAD-DM2- revealed significantly higher concentrations of VEGF-A （P=-0.000007 and P=0.0000001, respectively） and significantly lower sVEGFR-2 levels （P=-0.02 and P=-0.00001, respectively）, when compared with the control group. Patients with PAD and coexistent diabetes tended to have a lower level of VEGF-A and higher levels of sVEGFR-1 and sVEGFR-2 comparable with non-diabetic patients. Conclusions： The coexistence of type 2 diabetes and PAD is demonstrated by a tendency to a lower plasma level of proangiogenic factor （VEGF-A） and higher levels of anglogenesis inhibitors （sVEGFR-1 and sVEGFR-2） at the same time. Regardless of the coexistence of type 2 diabetes, hypoxia appears to be a crucial factor stimulating the processes of angiogenesis in PAD patients comparable with healthy individuals, whereas hyperglycemia may have a negative impact on angiogenesis in lower limbs.

Quasi-periodic Solutions for the Derivative Nonlinear Schrdinger Equation with Finitely Differentiable Nonlinearities

The authors are concerned with a class of derivative nonlinear Schr¨odinger equation iu_t + u_(xx) + i?f(u, ū, ωt)u_x=0,(t, x) ∈ R × [0, π],subject to Dirichlet boundary condition, where the nonlinearity f(z1, z2, ?) is merely finitely differentiable with respect to all variables rather than analytic and quasi-periodically forced in time. By developing a smoothing and approximation theory, the existence of many quasi-periodic solutions of the above equation is proved.

Dynamical cavitation and oscillation of an anisotropic incompressible hyper-elastic sphere

Dynamical cavitation and oscillation of an anisotropic two-family fiber-reinforced incompressible hyper-elastic sphere subjected to a suddenly applied constant boundary dead load are examined within the framework of finite elasto-dynamics.An exact differential equation between the radius of the cavity and the applied load is obtained.The curves for the variation of the maximum radius of the cavity with the load and the phase diagrams are obtained by vibration theories and numerical computation.It is shown that there exists a critical value for the applied load.When the applied load is larger than the critical value,a spherical cavity will suddenly form at the center of the sphere.It is proved that the evolution of the cavity radius with time follows that of nonlinear periodic oscillation,and oscillation of the anisotropic sphere is not the same as that of the isotropic sphere.

Overweight and obesity versus concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 in plasma of patients with lower limb chronic ischemia

Objective： Being overweight or obese comprises a significant risk factor for atherosclerosis. Fat tissue also generates factors stimulating angiogenesis, the process by which new blood vessels form. The purpose of this paper is to assess concentrations of the vascular endothelial growth factor A （VEGF-A） and its soluble type-1 and type-2 re- ceptors （sVEGFR-1 and sVEGFR-2） in plasma of patients with peripheral arterial disease （PAD） depending on the level of nutrition according to body mass index （BMI）. Methods： The study group included patients suffering from symptomatic PAD （n=46） in Fontaine classes Ila-lV without any history of neoplastic disease and who have a normal BMI （n=15）, are overweight （n=21） or are obese （n=10）. The control group （n=30） consisted of healthy non-smoking volunteers who were neither overweight nor obese. Venous blood plasma samples were collected from both groups at rest in the morning to determine plasma concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 using the enzyme- linked immunosorbent assay （ELISA） method. Results： The group of patients with PAD co-existent with being over- weight or obese tended to have higher mean concentration levels of VEGF-A and sVEGFR-2 when compared with patients suffering from PAD with normal BMIo A statistically significant positive correlation was obtained between BMI and average plasma concentrations of sVEGFR-2 （R=0.37, P=-0.0103）. However, no significant correlation was no- ticed between BMI and VEGF-A or sVEGFR-1 concentrations. Conclusions： A positive correlation determined be- tween the level of antiangiogenic factor and BMI value may be indicative of the linearly growing prevalence of some antiangiogenic factors in patients with metabolic disorders, which may be one of numerous factors contributing to incomplete efficiency of collateral circulation development in patients with PAD.