Analysis of Reliability for 3-State Device Network with Link-Capacities

This paper presents a concept of the 3-state device system with link-capacity, whichcan, besides its normal operative state, assume two different failure states: an open-mode and ashorted-mode failure state. The 3-state system reliability analysis often uses flow required andprobability of the device to compute the probability of the system with link-capacity. We use themethod of max-flow and min-cut theorem, give four theorems to reduce 3-state device network withlink-capacity reliability problems to 2-state problems. For practical, relevant network sizes (up to100 components), the algorithm is fast and efficient.

Simulation Analysis of Car Front Collision Based on LS-DYNA and Hyper Works

Based on the basic principle of vehicle crash analysis using the finite element method, a car finite element model was built by using Hypermesh software. To simulate the front collision test of the car, the LS-DYNA software is adopted to calculate the deformation of the car and the acceleration time history curves during the crashing process;the anti-impact capability of the car is evaluated from this simulation. The results demonstrate that the improvement of local structure can promote the crashworthiness of the car, but the further improvement needs a major change of the car structure.

Synthesis of indirect work exchange networks considering both isothermal and adiabatic process together with exergy analysis

In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In contrast with superstructure method, the transshipment model is easier to obtain the minimum utility consumption taken as the objective function and more convenient for us to attain the optimal network configuration for further minimizing the number of units. Different from division of temperature intervals in heat exchange networks,different pressure intervals are gained according to the maximum compression/expansion ratio in consideration of operating principles of indirect work exchangers and the characteristics of no pressure constraints for stream matches. The presented approach for WEN synthesis is a linear programming model applied to the isothermal process, but for indirect work exchange networks with adiabatic process, a nonlinear programming model needs establishing. Additionally, temperatures should be regarded as decision variables limited to the range between inlet and outlet temperatures in each sub-network. The constructed transshipment model can be solved first to get the minimum utility consumption and further to determine the minimum number of units by merging the adjacent pressure intervals on the basis of the proposed merging methods, which is proved to be effective through exergy analysis at the level of units structures. Finally, two cases are calculated to confirm it is dramatically feasible and effective that the optimal WEN configuration can be gained by the proposed method.

Cognitive work analysis to comprehend operations and organizations in the mining industry

Complex industrial systems, including mining, have a prominent challenge in understanding the interrelationship among the cognitive processes, working environment and available equipment. The concept of cognitive work analysis(CWA) transcends the traditional analytic methods of evaluating human tasks solely based on perceptual and physical traits, and rather implements the notions of behavioral and cognitive awareness indispensable for the intricacy of modern technology. In the last few decades, academic and industrial settings employ this type of analysis to set a suitable standard for a system's safety feasibility, and as a result reduce human-based errors. This research paper analyzes current CWA methods and proposes a five-level quantification model portraying the overall cognitive quality of a mining operation.

A Framework for Web-Based Mechanical Design and Analysis

In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec hanical system design and analysis process. This system is based on an emerg ing web-based Content Management System (CMS) called eXtended Object Oriented P ortal System (XOOPS). Due to the Open Source Status of the XOOPS CMS, programs d eveloped with this framework can be further customized to satisfy the demands of the user. To introduce the use of this framework, this paper exams three differ ent types of mechanical design and analysis problems. First, a repetitive design consideration and calculation process is transferred into WMADF programs to gai n efficiency for wired collaborative team. Second, the considered product solid model is created directly through the use of XOOPS program and Microsoft Compone nt Object Model (COM) instances. To the end of the paper, an example linked with ANSYS is used to indicate the possible application of this framework.

Basic Works of Flash Flood Disaster Analysis and Assessment in Rucheng County of Hunan Province

The method and experience of basic work of flash flood disaster analysis and assessment in early period are introduced in a case of Rucheng County,Chenzhou City,Hunan Province,containing analysis of general situation in county region,excavation of working map information,determination of assessment object list,examination of investigated data,and standardized arrangement of data. Finally,the suggestions for basic work of analysis and assessment are given,which could provide the references for implementing analysis and assessment work of flash flood disaster in other regions.

Separation work analysis of cohesive law and consistently coupled cohesive law

An appropriate coupled cohesive law for predicting the mixed mode failure is established by combining normal separation and tangential separation of surfaces in the cohesive zone model （CZM） and the cohesive element method. The Xu-Needleman exponential cohesive law with the fully shear failure mechanism is one of the most popular models. Based on the proposed consistently coupled rule/principle, the Xu-Needleman law with the fully shear failure mechanism is proved to be a non-consistently coupled cohesive law by analyzing the surface separation work. It is shown that the Xu-Needleman law is only valid in the mixed mode fracture when the normal separation work equals the tangential separation work. Based on the consistently coupled principle and the modification of the Xu-Needleman law, a consistently coupled cohesive （CCC） law is given. It is shown that the proposed CCC law has already overcome the non-consistency defect of the Xu-Needleman law with great promise in mixed mode analyses.

Path Analysis of Rural Social Work Intervention in Precision Poverty Alleviation in Sichuan Province

The targeted poverty alleviation policy isone of the important methods to solve the problemof poverty in China. After the implementation of thetargeted poverty alleviation policy in China, someresults have shown positive. However, due to theshortage of resources and talents for poverty alleviation,there are still some shortcomings in the targeted povertyalleviation work. In the process of targeted povertyalleviation, if we can promote social work to participatein targeted poverty alleviation and use a wider rangeof social forces to provide more professional andtargeted assistance work for the poor, we will achievethe final sprint for the success of targeted povertyalleviation in China and a well-off society. Based onthe actual situation of China’s current targeted povertyalleviation work, this article takes the relationship andcontent of rural social work in Sichuan Province aspart of the targeted poverty alleviation as well as thedifficulties it faces. The analysis focuses on the pathof rural social work in Sichuan Province to targetedpoverty alleviation and aims to provide more referencesuggestions for targeted poverty alleviation in China.

A Critical Analysis of Group Work in Chinese University EFL Classes

In the past few years,group activities have been warmly welcomed by EFL(English as a foreign language)classes in Chi-na,but few studies have discussed it from a critical perspective.Thus,this study explores from students’experiences what and whythe strengths and weaknesses of group work in actual contexts appear.The findings reveal that Chinese learners regard group workas an effective interactive activity for language,personal,and emotional development.However,the possible pitfalls,such as pseu-dogroups,unequal participation,groupthink,L1(first language)influence may prevent learners from obtaining the benefits of CL(collaborative learning).Finally,some suggestions are given,with the purpose of creating a more suitable facilitative EFL classroomenvironment for future Chinese EFL teaching and learning.

Dynamic Analysis and Performance Verification of a Novel Hip Prosthetic Mechanism

To assist an amputee in regaining his or her daily quality of life,based on analysis of the motion characteristics of the human hip,a 2-UPR/URR parallel mechanism with a passive limb was designed.The inverse kinematics of this mechanism was analyzed based on a closed-loop vector method.The constrained Jacobian matrix and kinematic Jacobian matrix of each limb were then analyzed,and a 6×6 fully Jacobian matrix was constructed.Based on this,kinematic performances were analyzed and summarized.Finally,the dynamic model of the mechanism was constructed based on the virtual work principle,and its theoretical solution was compared with the numerical results,which were obtained in a simulation environment.Results showed that the prosthetic mechanism had a larger rotating workspace and better mechanical performance,which accorded a range of motion and bearing capacity similar to that of the human hip in multiple gait modes.Moreover,the validity of the dynamic model and inverse kinematics were verified by comparing the theoretical and simulation results.Furthermore,with flexion and extension,the torque change in the hip prosthetic mechanism was similar to that of the human hip,which demonstrated the feasibility of the hip prosthetic mechanism and its good dynamic performance.

Energy efficiency evaluation based on DEA integrated factor analysis in ethylene production

Energy efficiency evaluation plays an important role in energy efficiency improvement of the ethylene production. It is observed from the actual production data that the ethylene production energy efficiency often varies with the complex production working conditions. In the favored methods for energy efficiency evaluation,DEA models may show poor resolution when directly used to evaluate the efficiency values. Therefore, a new energy efficiency evaluation method for ethylene production is proposed based on DEA integrated factor analysis with respect to operation classification. Three key factors, including raw material composition, cracking depth and load rate, are taken into account in determining the production working conditions by means of k-means algorithm. Based on the multi-working conditions mode the energy efficiency evaluation of the ethylene production is made by using DEA model, where the most related energy data are screened by factor analysis.Furthermore, the supporting decision of energy efficiency improvement is provided to the operators. The accuracy and effectiveness of the proposed method are illustrated by applying in a practical ethylene production,which gives more effective energy efficiency evaluation in the complicated working conditions of ethylene production with declined dimension of input indicators.

Wear and Thermal Stress Analysis of Side Dam for Twin Roll Strip Casting

The simulation of the work roll temperature field was carried out by means of ANSYS software, and the thermal crown of the roll along its axis was obtained. The thermal-structural coupled element and contact element were introduced. In the simulation of work roll temperature field, the convert boundary condition and the transient thermal contact between the roll and strip were studied. Besides, the dynamic variation of the work roll temperature and the transient temperature distribution of the work roll during hot rolling were investigated. The calculated results were in good agreement with the measured data.

Identifying Game Processes Based on Private Working Sets

Fueled by the booming online games,there is an increasing demand for monitoring online games in various settings.One of the application scenarios is the monitor of computer games in school computer labs,for which an intelligent game recognition method is required.In this paper,a method to identify game processes in accordance with private working sets(i.e.,the amount of memory occupied by a process but cannot be shared among other processes)is introduced.Results of the W test showed that the memory sizes occupied by the legitimate processes(e.g.,the processes of common native windows applications)and game processes followed normal distribution.Using the T-test,a significant difference was identified between the legitimate processes and C/S-based computer games,in terms of the means and variances of their private working sets.Subsequently,we derived the density functions of the private working sets of the considered game processes and those of the legitimate processes.Given the private working set of a process and the derived probability density functions,the probability that the process is a legitimate process and the probability that the process is a game process can be determined.After comparing the two probabilities,we can easily determine whether the process is a game process or not.As revealed from the test results,the recognition accuracy of this method for C/S-based computer games was approximately 90%.

X-ray peak profile analysis of dislocation type,density and crystallite size distribution in cold deformed Pb-Ca-Sn alloys

The density,nature of the dislocations and distribution of the domain sizes in cold-deformed Pb-Ca-Sn solid solution were determined by X-ray diffraction profile analysis.The dislocation densities are of the order of 1010 cm-2.The strain broadening of diffraction profiles was accounted for by dislocation contrast factor.The coherent domain size was determined by the recently developed PM2K software package.Assuming that the domain size distribution is log-normal,the distribution function（median μ and variance σ） was calculated from the size parameters determined from X-ray diffraction profile analysis.

Simulation Modeling and Analysis of Operator-Machine Ratio

Based on a simulation model of a semiconductor manufacturer, operator-machine ratio （OMR） analysis is made using work study and time study. Through sensitivity analysis, it is found that labor utilization decreases with the increase of lot size. Meanwhile, it is able to identify that the OMR for this company should be improved from 1 ： 3 to 1 ： 5. An application result shows that the proposed model can effectively improve the OMR by 33%.

An analysis method of injection and production dynamic transient flow in a gas field storage facility

A dynamic transient flow analysis method considering complex factors such as the cyclic injection and production history in a gas field storage facility was established in view of the limitations of the existing methods for transient flow analysis and the characteristics of the injection-production operation of strongly heterogeneous gas reservoirs, and the corresponding theoretical charts were drawn. In addition, an injection-production dynamic transient flow analysis model named "three points and two stages" suitable for an underground gas storage(UGS) well with alternate working conditions was proposed. The "three points" refer to three time points during cyclic injection and production, namely, the starting point of gas injection for UGS construction, the beginning and ending points of the injection-production analysis stage;and the "two stages" refer to historical flow stage and injection-production analysis stage. The study shows that the dimensionless pseudo-pressure and dimensionless pseudo-pressure integral curves of UGS well flex downward in the early stage of the injection and production process, and the dimensionless pseudo-pressure integral derivative curve is convex during the gas production period and concave during the gas injection period, and the curves under different flow histories have atypical features. The new method present in this paper can analyze transient flow of UGS accurately. The application of this method to typical wells in Hutubi gas storage shows that the new method can fit the pressure history accurately, and obtain reliable parameters and results.

Analysis on the Failure Causes of the Collapsed Tubing in an Oil Well

Due to the influence of multiple factors such as internal and external formation and mechanical pressure, medium corrosion and construction operation environment, a tubing collapse failure occurred in an oil well. In order to determine the failure cause of the tubing, physical and chemical tests and mechanical properties analysis were carried out on the failed tubing sample and the intact tubing. The results show that the chemical composition, ultrasonic and magnetic particle inspection, metallographic test, Charpy impact energy and external pressure mechanical property test of the failed tubing all meet the requirements of API Spec 5CT-2021 standard, but the yield strength of the failed tubing does not meet the requirements of API Spec 5CT-2021 standard. Through the analysis of the working conditions, it can be seen that the anti-extrusion strength of the tubing collapse does not meet the API 5C3 anti-extrusion strength standard. The failure type of the well tubing is tubing collapse caused by large internal and external pressure difference.

Facing Both Challenges and Opportunities:How Can Financial Service Firms Survive Under the Pandemic?SOAR Analysis of Three Leading Firms in the Financial Service Industry

After the breakout of COVID-19,many entity industries have to shut down.The rapid decline of money transaction caused by the shutdown of the entity industries has shocked the financial service industry while the increase in digital transactions also offers them opportunities.Facing both challenges and opportunities,financial services firms should change their target and compensation policy during the pandemic to survive.After analysing three major firms in this industry by using SOAR method,we conclude four keys for financial services firms to survive in COVID-19.

Factors Influencing Migrant Workers' Urban Labor Patterns: Willing Working Time in Urban Areas as the Mediator

China is witnessing a very complicated economic development environment.Migrant workers'working patterns will directly affect their income level and the realization of many economic and social development goals.This paper collects relevant data from three places:Shanghai,Lanzhou and Chengdu for empirical research whose results show that determinants of migrant worker's willing working time in urban areas mainly include the“income-consumption difference”,“urban-rural consumption difference”and their“urban income and expenditure uncertainty”.These factors directly affect their effective working time in the city,and determine their choice of choosing corresponding work patterns.From the significant differences of these factors,we can see that migrant workers in China is still struggling to solve their material needs under the pressure of livelihood,and less attention is paid to their spiritual needs and the pursuit of quality of life.