An efficient formulation based on the Lagrangian method for contact–impact analysis of flexible multi-body system

In this paper,an efficien formulation based on the Lagrangian method is presented to investigate the contact–impact problems of f exible multi-body systems.Generally,the penalty method and the Hertz contact law are the most commonly used methods in engineering applications.However,these methods are highly dependent on various non-physical parameters,which have great effects on the simulation results.Moreover,a tremendous number of degrees of freedom in the contact–impact problems will influenc thenumericalefficien ysignificantl.Withtheconsideration of these two problems,a formulation combining the component mode synthesis method and the Lagrangian method is presented to investigate the contact–impact problems in fl xible multi-body system numerically.Meanwhile,the finit element meshing laws of the contact bodies will be studied preliminarily.A numerical example with experimental verificatio will certify the reliability of the presented formulationincontact–impactanalysis.Furthermore,aseries of numerical investigations explain how great the influenc of the finit element meshing has on the simulation results.Finally the limitations of the element size in different regions are summarized to satisfy both the accuracy and efficien y.

A Two-folded Impact Analysis of Schema Changes on Database Applications

Database applications are becoming increasingly popular, mainly due to the advanced data management facilities that the underlying database management system offers compared against traditional legacy software applications. The interaction, however, of such applications with the database system introduces a number of issues, among which, this paper addresses the impact analysis of the changes performed at the database schema level. Our motivation is to provide the software engineers of database applications with automated methods that facilitate major maintenance tasks, such as source code corrections and regression testing, which should be triggered by the occurrence of such changes. The presented impact analysis is thus two-folded： the impact is analysed in terms of both the affected source code statements and the affected test suites concerning the testing of these applications. To achieve the former objective, a program slicing technique is employed, which is based on an extended version of the program dependency graph. The latter objective requires the analysis of test suites generated for database applications, which is accomplished by employing testing techniques tailored for this type of applications. Utilising both the slicing and the testing techniques enhances program comprehension of database applications, while also supporting the development of a number of practical metrics regarding their maintainability against schema changes. To evaluate the feasibility and effectiveness of the presented techniques and metrics, a software tool, called DATA, has been implemented. The experimental results from its usage on the TPC-C case study are reported and analysed.

LAPLACE TRANSFORM-BOUNDARY ELEMENT COUPLING METHOD FOR VISCOUS FLUIDSTRUCTURE IMPACT ANALYSIS

Based on linearized 2-D Navier-Stokes equation, a Laplacetransform-boundary element coupling method for viscousfluid-structure impact analysis is proposed. Under assumption ofincompressibility for the fluid, the corresponding equivalentboundary integral equation in terms of the potential function andstream function is first established by Lamb's transform in theLaplace transform domain.

Municipal Temperature and Heatwave Predictions as a Tool for Integrated Socio-Environmental Impact Analysis in Brazil

Numerical climate models render data in a gridded format which is often problematic for integrated analysis with other kinds of data in jurisdictional formats. In this paper a joint analysis of municipal Gross Domestic Product per capita (GDPc) and predicted temperature increase was undertaken in order to estimate different levels of human and economic exposure. This is based on a method of converting model outputs into a country municipal grid which enabled depicting climate predictions from the Eta-Hadgem2-ES Regional Climate Model (RCM) into the municipal level in Brazil. The conversion to country municipality grid was made using a combination of interpolation and buffering techniques in ArcGIS for two emission scenarios (RCP 4.5 and 8.5) and three timeframes (2011-2040, 2041-2070, 2071-2100) for mean temperature increase and number of heatwave days (WSDI). The results were used to support the Third National Communication (TCN) of Brazil to the United Nations Framework Convention on Climate Change (UNFCCC) and show a coherent matching of the gridded output from the original RCM. The joint climate and GDPc analysis show that in the beginning of the century the more severe warming is centred over regions where GDPc is generally higher (Centre-West and Southeast). At the end of the century, critical levels of warming spread north and northeastwards where municipalities have the lowest GDPc levels. In the high emission scenario (RCP 8.5), the strongest warming and the spreading over poorer regions are anticipated to the mid-century. These results are the key to further explore solutions for climate change adaptation based on current resources and prepare in different sectors, for long-term risk management and climate adaptation planning strategies.

Trend Impact Analysis of Dissolved Nutrients Released From Soil on Water Quality in Qinglongshan Reservoir

During the storage of water and the initial running of a reservoir, part of the dissolved nutrients released from the soil in water will effect water quality. Taking Qinglongshan Reservoir as an example, estimating the value of the contribution of dissolved nutrients to the water quality and analyzing the trend or level of the dissolved nutrients effecting on the water quality under the soil nutrient inquiring, the soil nutrient monitoring, and the dissolving experiment of nutrients released from soil, also according to the capacity curve of Qinglongshan Reservoir.

Impact analysis of casting parts considering shrinkage cavity defect

Shrinkage cavity may be detrimental to mechanical performances of casting parts.As a consequence,design engineers often use overly large safety factors in many designs due to insufficient understanding of quantitative effects of shrinkage cavity defects.In this paper,process of Al alloy wheel impact test was computationally analyzed for both the wheel models with and without shrinkage cavity defects.Based on shrinkage cavity data obtained from industrial CT (Computerized Tomography),the shrinkage cavity defects were modeled with SSM (Shape Simplification Method),which reconstructs shrinkage cavity defects to hollow spheroid primitives.After the impact simulation was conducted,the results show that under impact test condition,the wheel considering shrinkage cavity defects may fracture while the sound-assumed wheel may not.

Managing Hepatitis C Patients in Greece: A Budget Impact Analysis of Simeprevir plus Pegylated Interferon/Ribavirin Regimen at Early Stages of the Disease

Objectives: To identify local resource use such as pharmaceutical treatment, medical follow-up, and patient hospitalization and estimate the budget impact of simeprevir (SMV) plus pegylated interferon (P)/ribavirin (R) as a treatment option in the early stages of the disease in Greece. Methods: A budget impact tool was developed with a two-year time horizon, which estimated the impact on the Social Insurance Funds (SIFs) of introducing SMV + PR in the management of the early disease stages. Total direct and indirect costs were estimated for each of the following health states: non-cirrhotic chronic Hepatitis C (and within that by fibrosis stage), compensated cirrhosis, decompensated cirrhosis, and hepatocellular carcinoma. Data gaps on treatment algorithms, resource use and productivity losses were covered via an expert panel of eight leading hepatologists. Epidemiology data were taken from the published literature. Unit costs were obtained from the Ministry of Health and SIFs. The perspective was that of the SIF and the cost base year was 2015. Results: The total (direct and indirect) cost per patient per year (excluding cost of antiviral treatment) was estimated at €647, €703, €5,753, €16,313 and €37,237 for non-cirrhotic CHC, compensated cirrhosis, decompensated cirrhosis, HCC and liver transplantation, respectively. The budget impact analysis showed that adding SMV to PR in the early stages of the disease would lead to an increase in the cost of antiviral treatment by €2.03 million. Conclusions: Costs of managing CHC increase dramatically with disease severity. SMV + PR for naive patients at early disease stages has a significant but manageable budget impact, and could prevent high costs in advanced stages.

The impact analysis of policy events on China's carbon market

This paper interrogates the impact of policy events on the efficiency of carbon market in China.The analysis covers five piloting emission trading schemes(Beijing, Shanghai, Guangdong,Shenzhen and Hubei), particularly focusing on Guangdong pilot for its weak form efficiency and the richness of policy events. Twenty-five policy events between 2014 and 2016 are categorized into seven groups. The efficiency test indicates that only Guangdong ETS has reached weak form efficiency. After exploring the policy events occurred in Guangdong ETS, it finds that although a clear long-term climate policy has been set up over the country, China's carbon market still has a conservative risk appetite and its governing institutions still needs further development. The policy makers need to be aware of and avoid the negative impacts of policy events to the market evolvement, by introducing effective consultancy process with the stakeholders and nurturing market expectations in the long run. We also find that events like allowance auctions have considerably less impacts than previously expected and argue that auction approach should be considered a preferable option over a free allocation system in the future policy design.

Impact of primary percutaneous coronary intervention on ST-segment elevation myocardial infarction patients:A comprehensive analysis

BACKGROUND Myocardial infarction,particularly ST-segment elevation myocardial infarction(STEMI),is a key global mortality cause.Our study investigated predictors of mortality in 96 STEMI patients undergoing primary percutaneous coronary intervention at Erbil Cardiac Center.Multiple factors were identified influencing in-hospital mortality.Significantly,time from symptom onset to hospital arrival emerged as a decisive factor.Consequently,our study hypothesis is:"Reducing time from symptom onset to hospital arrival significantly improves STEMI prognosis."AIM To determine the key factors influencing mortality rates in STEMI patients.METHODS We studied 96 consecutive STEMI patients undergoing primary percutaneous coronary intervention(PPCI)at the Erbil Cardiac Center.Their clinical histories were compiled,and coronary evaluations were performed via angiography on admission.Data included comorbid conditions,onset of cardiogenic shock,complications during PPCI,and more.Post-discharge,one-month follow-up assessments were completed.Statistical significance was set at P<0.05.RESULTS Our results unearthed several significant findings.The in-hospital and 30-d mortality rates among the 96 STEMI patients were 11.2%and 2.3%respectively.On the investigation of independent predictors of in-hospital mortality,we identified atypical presentation,onset of cardiogenic shock,presence of chronic kidney disease,Thrombolysis In Myocardial Infarction grades 0/1/2,triple vessel disease,ventricular tachycardia/ventricular fibrillation,coronary dissection,and the no-reflow phenomenon.Specifically,the recorded average time from symptom onset to hospital arrival amongst patients who did not survive was significantly longer(6.92±3.86 h)compared to those who survived(3.61±1.67 h),P<0.001.These findings underscore the critical role of timely intervention in improving the survival outcomes of STEMI patients.CONCLUSION Our results affirm that early hospital arrival after symptom onset significantly improves survival rates in STEMI patients,highlighting the critical need for prompt intervention.

Traffic Impact Analysis of the Access to Projects on Traffic Performance of Nearby Roadways

Access to any development is a connection between the buildings and urban roadways. The impact of access on urban roads varies with location of the access. This paper studies the impact of access to large buildings on the surrounding road network by exploring traffic conflicts based on the configuration of the access. The concept of conflict intensity is introduced in this study as a new evaluation indicator to evaluate the traffic conflict triggered by the presence of access. The results show that the greater the speed,the greater the conflict intensity of access. Meanwhile,a similar situation exists when other variables （e.g.,conflict angle or the number of conflicts） change. The larger the conflict intensity,the more dangerous the access. Results from this study can help developers and traffic engineers choose suitable locations of access and organize the traffic in a logical manner.

Fast Screening Severe Cyber Attacks via Transient Energy-based Impact Analysis

This paper presents a transient energy based screening approach for quickly identifying potential critical attacks that might have significant impacts on power system transient stability.Specifically,the proposed approach focuses on the total transient energy injected into power systems as the result of assumptive cyber attacks.The computational improvements of the proposed method are significant as the time-domain simulations can be avoided.The efficacy of the proposed approach is demonstrated using a practical power system with various cyber attack scenarios.The identification results of the proposed method can be used to guide more detailed impact analysis and to develop more effective countermeasures against cyber attacks.

Analysis on the Impact of Facility Agriculture Development on Climate Change in Weifang

[Objective] The research aimed to study the influence of facility agriculture development on the climate variation in Weifang. [Method] Shouguang was selected as the representative station of greenhouse shed planting zone. By using the precipitation, temperature and relative humidity, etc. in Weifang City during 1961-2010, the climatic variation situations in the whole city and the greenhouse shed planting zone were analyzed. The variation trend and evolution characteristics of climate in the different seasons before and after the facility agriculture plantation were contrasted and analyzed. [Result] The annual rainfall and relative humidity presented the declining trend in the whole city in recent 50 years. The annual average, maximum and minimum temperatures all presented the rising trend. Since the large-scale plantation of greenhouse shed, the declining range of annual rainfall in the greenhouse shed planting zone was lower than that in the whole city, and the declining range of relative humidity was obviously higher than that in the whole city. The rising ranges of annual average, maximum and minimum temperatures were higher than that in the whole city. [Conclusion] The research provided the theory basis for the development of facility agriculture.

Fatigue and impact analysis and multi-objective optimization design of Mg/Al assembled wheel considering riveting residual stress

The multi-material assembled light alloy wheel presents an effective lightweight solution for new energy vehicles,but its riveting connection remains a problem.To address this problem,this paper proposed the explicit riveting-implicit springback-implicit fatigue/explicit impact sequence coupling simulation analysis method,analyzed the fatigue and impact performance of the punching riveting connected magnesium/aluminum alloy(Mg/Al)assembled wheel,and constructed some major evaluation indicators.The accuracy of the proposed simulation method was verified by conducting physical experiments of single and cross lap joints.The punching riveting process parameters of the assembled wheel joints were defined as design variables,and the fatigue and impact performance of the assembled wheel was defined as the optimization objective.The connection-performance integration multi-objective optimization design of the assembled wheel considering riveting residual stress was designed via Taguchi experiment,grey relational analysis,analytic hierarchy process,principal component analysis,and entropy weighting methods.The optimization results of the three weighting methods were compared,and the optimal combination of design variables was determined.The fatigue and impact performance of the Mg/Al assembled wheel were effectively improved after optimization.

Predictive value and impact analysis for the index of microcirculatory resistance in MI patients with elective percutaneous coronary intervention

Objective To evaluate the predictive value and impact for the index of microcirculatory resistance(IMR)in myocardial infarction(MI)patients with elective percutaneous coronary intervention(PCI)for treating coronary artery occlusion.Methods A total of 34 patients with STEMI or non-STEMI treated after 12h time window

A Study of the Impact of Personality and Social Psychology on Mental Health

With the continuous development and progress of economy,people's living standard and culture level have been improved,but with it,there are also various kinds of life stress,study stress and work stress,which make people's mental health problems in life more andmore prominent,and how to improve students'mental health level is the main task of each education stage.The current psychology discipline system has been perfected,including personality psychology and social psychology,which are effectively applied in the actual mental health education or psychological guidance work,and are key disciplines to improve people's mental health.The theoretical system of personality and social psychology consists of three theories:the theory of planned behavior,the theory of explanatory levels,and the theory of self-determination,all of which have an irreplaceable influence on mental health.In this regard,this paper combines relevant literature and work experience to study in depth the influence of personality ansocial psychology on mental health.

Analysis of tritium production in a 2 MW liquid-fueled molten salt experimental reactor and its environmental impact

Tritium release is one of the most concerning topics in nuclear power plants. Here, the tritium production in a 2 MW liquid-fueled molten salt experimental reactor(TMSR-LF1) was calculated by ORIGEN-S with an updated cross-section library generated by TRITON in SCALE 6.1.3 code system. The results show that the tritium production rate and normalized tritium production rate of TMSR-LF1 are 8.90x10^(11)Bq/day and4.45x10^(11)Bq/(MW day), respectively. The environmental impact of tritium was analyzed via PC-CREAM 08 with an assumed 36 % release rate of tritium referring to the molten salt reactor experiment. During normal operations, the maximum tritium concentration is 1.4 Bq/m^3 under normal condition, and the corresponding individual dose to the public is about 1 μSv/a; under extreme conditions, the maximum concentration and corresponding individual doses are 11.8 Bq/m^3 and 9 μSv/a, respectively.Ingestion is the main exposure pathway and accounts for62 % of the total dose. Of this, 35 % is from organically bound tritium.

Analysis of hydrogeolgical characteristics and water environmental impact pathway of typical shale gas exploration and development zones in Sichuan Basin, China

Studying the influence of shale gas exploration and development on groundwater environment is the basis of guiding water environment protection in the process of shale gas exploration and development.Groundwater environmental pollution is concealed,complex and persistent.Once it is difficult to control the pollution,the current commercial shale gas development zones in Sichuan Basin that are mostly located in karst areas and highly sensitive to groundwater will be vulnerable to the impact of shale gas exploration and development.Based on the hydrogeological conditions of shale gas exploration and development area and combined with engineering analysis of exploration and development,various risk pathways that may affect the groundwater environment during process of shale gas exploration,mining well construction,mining operations and other stages were identified in this paper.Some existing risk pathways were proved by verification of typical areas and should not be ignored.Based on the actual situation of typical areas,the countermeasures of groundwater environmental protection in the process of shale gas exploration and development in karst areas were discussed.It is believed that the groundwater environment can be better protected by strengthening administration,research and application of new technologies,precise design,hydrogeological conditions,and research and feedback of groundwater environmental protection.

Calculation of Ecological Footprint Based on Modified Method and Quantitative Analysis of Its Impact Factors——A Case Study of Shanghai

Ecological footprint(EF) has attracted much attention internationally as a potential indicator for sustainable development.In China,EF has also gained recognition in related fields and disciplines.Moreover,some scholars in these fields have proposed alternative methods to calculate EF and have made some progress.This paper,therefore,begins with the introduction and development of EF in China.However,the established methods of EF calculation hold some limitations,such as indicator variance and result abnormality.In order to resolve those problems,the authors make a further modification considering the demand of EF as a comprehensive indicator:1) More accurate analysis has been done to divide EF into several parts:imported EF,exported EF,and producible EF,which is the solution to the problem of abnormality in original EF results and can explain abnormal phenomena reasonably.2) Considering the actual situa-tion of Shanghai,amended equivalence factor is brought forward and a matrix is formed with equivalence factors.The measure can reduce the deviation between the fact and the results.3) The calculation compares local yield with global average yield to analyze the effects of yields.And based on local yields in different years,the results are more accurate.Finally,the calculation method is applied to calculating EF of Shanghai from 1980 to 2003,and the subsequent detailed analysis is presented.Available data and results suggest a statistically significant correlation coefficient between EF and GDP,population density and urbanization level.Through analyzing the process of calculating EF and its results,it can be seen that EF,as a macro-indicator,can not exactly indicate whether development within a region can meet the re-quests of sustainable development,which can be explained by the fact that the result of EF is impacted greatly by sub-jective factors including national policy,available technology,population,etc.Nevertheless,EF can demonstrate,at least to some degree,the regional status in terms of resources and energy consumption,as well as developmental potential.The calculation of EF,therefore,deserves further research to achieve more far-reaching significance in application.