Analysis on Operational Safety and Efficiency of FAO System in Urban Rail Transit

This paper discusses two urgent problems that need to be solved in fully automatic operation(FAO)for urban rail transit.The first is the analysis of safety in FAO,while another is the analysis of efficiency in FAO.Firstly,this paper establishes an operational safety evaluation index system from the perspective of operation for the unique or typical risk sources of the FAO system,and uses the analytic hierarchy process(AHP)to evaluate the indicators,analyzes various factors that affect the safe operation of FAO,and provides safety management recommendations for FAO lines operation to maintain the FAO system specifically.Secondly,taking the Yanfang Line as an example,this paper uses OpenTrack software to analyze the efficiency of FAO operation,and conducts simulation calculations for key links such as the mainline tracking interval,train entry and exit,and return limit interval.The fault impact surface of the FAO trains is simulated and discussed to verify whether FAO can meet the long-term operation requirements of Yanfang Line.Finally,this paper compares the simulation data of FAO on the Yanfang Line with manual operation(MO)to verify the advantages of FAO and guide the engineering construction of subsequent fully automated driving lines.

Ergonomic and efficiency analysis of conventional apple harvest process

Apples are still manually harvested by workers using ladders and buckets.Though it is known that manual apple harvest would probably lead to occupational injuries(e.g.,back,neck,and shoulder strains),there has been little research that focuses on identifying the awkward activities/postures of pickers during the harvest process.After categorizing apple harvest work into 12 activities,this study used the method of Rapid Upper Limb Assessment(RULA)to identify awkward postures/activities that occurred during apple harvest.Awkward activities confirmed include descending a ladder,dumping apples,picking high and low apples on a ladder as well as on the ground,and moving a ladder,with potential reasons for each awkward activity provided.Meanwhile,it was demonstrated that pickers spent approximately 64%of working time under awkward postures that would lead to occupational diseases.In addition,this study analyzed picker harvest efficiency in terms of general and detail manners.The general mode assessed harvest activity in terms of picking and non-picking,with results showing that pickers averagely spent 76%(±7%)of harvest time in picking apples.Further analysis evaluated picking activities in terms of reaching,detaching,and transporting apples,with results showing that pickers spent averagely 30%(±6%)of time in detaching apples,which is the value time during apple harvest.Furthermore,valuable picking time ratio was obtained as the multiplication of picking time ratio and detaching time ratio.With a valuable ratio of 22%(±5%),it theoretically demonstrated the low harvest efficiency of the traditional harvest method.Since a majority of the awkward activities and the low efficiency were because of the ladders/buckets,using a harvest-assist unit may be a potential solution.Additionally,more efforts should be spent on the development of innovative mechanism to replace worker in placing attached apples to the bucket.Once the time for transporting apples is eliminated,the time for reaching apples is also removed,indicating the harvest efficiency would be improved significantly.

Comprehensive Examination of Solar Panel Design: A Focus on Thermal Dynamics

In the 21st century, the deployment of ground-based Solar Photovoltaic (PV) Modules has seen exponential growth, driven by increasing demands for green, clean, and renewable energy sources. However, their usage is constrained by certain limitations. Notably, the efficiency of solar PV modules on the ground peaks at a maximum of 25%, and there are concerns regarding their long-term reliability, with an expected lifespan of approximately 25 years without failures. This study focuses on analyzing the thermal efficiency of PV Modules. We have investigated the temperature profile of PV Modules under varying environmental conditions, such as air velocity and ambient temperature, utilizing Computational Fluid Dynamics (CFD). This analysis is crucial as the efficiency of PV Modules is significantly impacted by changes in the temperature differential relative to the environment. Furthermore, the study highlights the effect of airflow over solar panels on their temperature. It is found that a decrease in the temperature of the PV Module increases Open Circuit Voltage, underlining the importance of thermal management in optimizing solar panel performance.

Approaches for High-Efficiency III-V/Si Tandem Solar Cells

The Si tandem solar cells are very attractive for realizing high efficiency and low cost. This paper overviews current status of III-V/Si tandem solar cells including our results. The analytical results for efficiency potential of Si tandem solar cells and loss analysis of Si bottom cells as well as bandgap energy optimization of sub-cells are presented. The 2-junction and 3-junction Si tandem solar cells have potential efficiencies of 36% and 42%, respectively. ERE (external radiative efficiency) analysis for Si solar cells is analyzed in order to clarify properties of Si bottom solar cells. Properties of single-crystalline Si heterojunction solar cell fabricated in this study were analyzed. The current status of efficiencies of our Si bottom cell, upper III-V 2-junction solar cell and III-V/Si 3-junction tandem solar cell was shown to be 5.2% and 28.6% and 33.8%. Achievement of Jsc of 12 mA/cm2 for Si bottom cell is necessary to realize high-efficiency 3-junction Si tandem solar cells with an efficiency of more than 37%. In addition, this paper presents ERE analysis of III-V 2-junction upper solar cells for improving III-V/Si 3-junction tandem solar cells. Several ways to improve efficiency of III-V/Si 3-junction tandem solar cells by reducing non-radiative recombination, optical and resistance losses are shown.

Advanced reliability analysis of slopes in spatially variable soils using multivariate adaptive regression splines

This study aims to extend the multivariate adaptive regression splines(MARS)-Monte Carlo simulation(MCS) method for reliability analysis of slopes in spatially variable soils. This approach is used to explore the influences of the multiscale spatial variability of soil properties on the probability of failure(P_f) of the slopes. In the proposed approach, the relationship between the factor of safety and the soil strength parameters characterized with spatial variability is approximated by the MARS, with the aid of Karhunen-Loeve expansion. MCS is subsequently performed on the established MARS model to evaluate Pf.Finally, a nominally homogeneous cohesive-frictional slope and a heterogeneous cohesive slope, which are both characterized with different spatial variabilities, are utilized to illustrate the proposed approach.Results showed that the proposed approach can estimate the P_f of the slopes efficiently in spatially variable soils with sufficient accuracy. Moreover, the approach is relatively robust to the influence of different statistics of soil properties, thereby making it an effective and practical tool for addressing slope reliability problems concerning time-consuming deterministic stability models with low levels of P_f.Furthermore, disregarding the multiscale spatial variability of soil properties can overestimate or underestimate the P_f. Although the difference is small in general, the multiscale spatial variability of the soil properties must still be considered in the reliability analysis of heterogeneous slopes, especially for those highly related to cost effective and accurate designs.

The Correlation of Hospital Operational Efficiency and Average Length of Stay in China: A Study Based on Provincial Level Data

Objective: To measure the hospital operation efficiency, study the correlation between average length of stay and hospital operation efficiency, analyze the importance of shortening average length of stay to the improvement of the hospital operation efficiency and put forward relevant policy suggestion. Methods: Based on China provincial panel data from 2003 to 2012, the hospital operation efficiencies are calculated using Super Efficiency Data Envelopment Analysis model, and the correlation between average length of stay and hospital operation efficiency is tested using Spearman rank correlation coefficient test. Results: From 2003 to 2012, the average of national hospital operation efficiency was increasing slowly and the hospital operations were inefficient in most of the areas. The national hospital operation efficiency is negatively correlated to the average length of stay. Conclusion: Measures should be taken to set average length of stay in a scientific and reasonable way, improve social and economic benefits based on the improvement of efficiency.

Efficient seismic analysis for nonlinear soil-structure interaction with a thick soil layer

The direct finite element method is a type commonly used for nonlinear seismic soil-structure interaction(SSI)analysis.This method introduces a truncated boundary referred to as an artificial boundary meant to divide the soil-structure system into finite and infinite domains.An artificial boundary condition is used on a truncated boundary to achieve seismic input and simulate the wave radiation effect of infinite domain.When the soil layer is particularly thick,especially for a three-dimensional problem,the computational efficiency of seismic SSI analysis is very low due to the large size of the finite element model,which contains an whole thick soil layer.In this paper,an accurate and efficient scheme is developed to solve the nonlinear seismic SSI problem regarding thick soil layers.The process consists of nonlinear site response and SSI analysis.The nonlinear site response analysis is still performed for the whole thick soil layer.The artificial boundary at the bottom of the SSI analysis model is subsequently relocated upward from the bottom of the soil layer(bedrock surface)to the location nearest to the structure as possible.Finally,three types of typical sites and underground structures are adopted with seismic SSI analysis to evaluate the accuracy and efficiency of the proposed efficient analysis scheme.

Repairable Configuration Optimization Model under Two-Echelon Inventory

Spares inventory configuration optimization is an effective way to improve readiness and reduce life cycle cost of equipment.Through analyzing two-echelon spares support system,the METRIC model basic theory was used.An inventory configuration optimization model of two-echelon spares support system was proposed which took the spares expected shortfall as the object and made the minimum repairable parts expected shortfall instead of the maximum spares supportability as the objective function.Marginal efficiency analysis algorithm was applied to optimizing the spares configuration and generating a rational spares inventory configuration.Finally,several examples are given to verify the model.

Measuring the social performance of forest management

Forests produce several types of benefits to both forest landowners and society.The social benefit of private forestry is equal to private benefit plus positive externalities minus negative externalities.This study developed alternative metrics for the evaluation of the social benefit of forest management.Forest management was assessed in terms of five criteria:economic,socio-cultural,environmental and ecological performance and the resilience of the forest ecosystem.Each criterion was described with three numerical indicators.Alternative performance indices were calculated from the indicator values using methods developed for multi-criteria decision making.It was concluded that indices based on the multiplicative Cobb-Douglas utility function might be the most recommendable when forestry should produce a balanced combination of different ecosystem services.When the indices were used to compare alternative silvicultural systems in terms of their social performance,continuous cover management was ranked better than even-aged management.The performance of even-aged management improved when it aimed at increasing the share of mixed stands and broadleaf species.Maximizing net present value(NPV) with a 1 % discount rate led to better social performance than maximizing NPV with a 4% discount rate.

Review on Modeling and Optimization for Refractories

This paper introduced characteristics of refractories and step of simulation. During simulation,firstly analyzed mechanism of technology; secondly described the mechanism as quadratic equation; thirdly designed and executed experiment; later made regression equation and optimization; then found technical conflict; finally analyzed and resolved the conflict. Doing repeatedly like this,resolved difficult problems.

Implementation of a greenhouse gas reduction roadmap for steel producing companies

This paper shall show an economic feasible approach to implement greenhouse gas(GHG) reduction measures into steel companies. The goal to improve energy consumption is directly linked to the reduction of GHG emissions and therefore directly in correlation with the economic viability. A baseline scenario of the considered reference system and of the respective reference year has to be defined, mapped and analysed. In a second step an analysis of the same operation using available and prospected best available technology (BAT) processes is carried out to generate a basis for a benchmark system. The identified reduction potentials are reported and the GHG emission reductions are put into relation to the investment cost of the new process technologies/process adaption to be implemented.This economic feasibility calculation is necessary to realise a cost efficient GHG reduction roadmap implementation into the company's business operations. The GHG reduction roadmap is developed using the abatement curve concept to get an indication of ' low hanging fruits' and for establishing a sequence for implementing carbon emission reductions measures. The scope of that approach can be extended by including further important environmental parameters like NOx, SO_2,CO,dust,heavy metal emissions in air as well as production residues.That gives in the end a broader picture and more starting points to improve the overall environmental performance of steel producing companies beyond the GHG emissions and energy consumption.

How to Pool Medical Services in Preventive Medicine Unit at 01/01/18 of Orleans Metropole/Orleans City Hall Structure: A Multi Disciplinary Network

To reform the unit of preventive medicine in Orleans metropole, the Director of the Administration decided to co-sign an agreement to optimize the organization of a common preventive medicine service: we made a deliberation model to permit for others towns which wanted to join us. The cost evaluated to reach the service was the cost for medical examination, regardless of the professional which included staff costs and operating costs (social benefits, costs of supplies and materials, training costs). A statement of the tasks performed for the beneficiary community was kept daily by the SMP. A strong will of the Metropolis and municipalities is to develop a synergy around health and safety at work. A joint Metropolis of Orleans, an organization chart since 1/2/2016 integrates the preventive medicine service within a Quality of Life at Work service: a multi-disciplinary service composed of prevention specialists, social workers, responsible for social action and SMP, a Department of Preventive Medicine was developed and itself multidisciplinary in accordance with the law of July 20, 2011: including doctors, nurses, psychologists, sophrologist, and a dietician. A new and active network of health is now operant with specialist correspondents. An audit is programmed in April 2018 to assess the efficacy of this network.

Integration of α-fairness with DEA based resource allocation model

How to allocate a resource efficiently and fairly attracts the attention of both researchers and practitioners. Data envelopment analysis（DEA） has been brought to bear on its solution. The existing literature applies Gini coefficient to measure the fairness in the resource allocation process. However, the Gini coefficient is inapplicable in many applications. This paper proposes a novel centralized resource allocation model based on DEA that considers both the efficiency and the fairness. This paper adopts a notion of fairness, namely α-fairness that is well studied in welfare economics and is of practical significance. The new model integratesα-fairness with DEA to support resource allocation decisions. It aids decision makers in making a trade-off between the efficiency and the fairness. An illustrative application is used to validate the proposed approach.

Data Envelopment Analysis Approach on the Industrial Efficiency and Scales and Its Application in Shandong

A data envelopment analysis (DEA ) model is set up for the industrial efficiency and scales evaluation in this paper. By calculating. the efficiency coefficient and the scale state of Shandong province in Chian are obtained. Based on the analysis results, the paper presents the improvement ways which make the industrial efficiency getting to the higher levell by adjusting the input and output variables of the industry of Shandong.

EFFICIENCY DECOMPOSITION WITH SHARED INPUTS AND OUTPUTS IN TWO-STAGE DEA

Data envelopment analysis （DEA） is an effective non-parametric method for measuring the relative efficiencies of decision making units （DMUs） with multiple inputs and outputs. In many real situations, the internal structure of DMUs is a two-stage network process with shared inputs used in both stages and common outputs produced by the both stages. For example, hospitals have a two-stage network structure. Stage 1 consumes resources such as information technology system, plant, equipment and admin personnel to generate outputs such as medical records, laundry and housekeeping. Stage 2 consumes the same set of resources used by stage 1 （named shared inputs） and the outputs generated by stage 1 （named intermediate measures） to provide patient services. Besides, some of outputs, for instance, patient satisfaction degrees, are generated by the two individual stages together （named shared outputs）. Since some of shared inputs and outputs are hard split up and allocated to each individual stage, it needs to develop two-stage DEA methods for evaluating the performance of two-stage network processes in such problems. This paper extends the centralized model to measure the DEA efficiency of the two-stage process with non split-table shared inputs and outputs. A weighted additive approach is used to combine the two individual stages. Moreover, additive efficiency decomposition models are developed to simultaneously evaluate the maximal and the minimal achievable efficiencies for the individual stages. Finally, an example of 17 city branches of China Construction Bank in Anhui Province is employed to illustrate the proposed approach.

Numerical research on airfoil transition delay by alternative current dielectric barrier discharge actuation

A Dielectric Barrier Discharge(DBD) plasma actuator can create a body force which locally accelerates the base flow leading to an attenuation of broadband disturbance to delay the transition. In this study, numerical simulation on an NLF0416 airfoil is conducted to investigate transition delay and drag reduction by a DBD plasma actuator. To simulate plasma’s effect more accurately, boundary-layer data is acquired from Reynolds Averaged Navier Stocks(RANS) equations instead of laminar boundary layer equations, although RANS equations need a much finer boundary-layer grid, and the linear stability analysis method is used to analyze the boundary layer and get the transition point. In this study, the influences of different actuation intensities and positions are investigated, and results show that if the actuation intensity is stronger and the actuation position is closer to the base transition point, more drag reduction can be obtained. However, the efficiency of plasma transition delay is really low. For example, when the actuation voltage is 16 k V,the actuation frequency is 1 k Hz, and the main Mach number is 0.1, the saved power due to drag reduction is about 5.09 W, but the power consumed is about 32.61 W, and the efficiency is just15.6%.

Optimal control strategies for preventing hepatitis B infection and reducing chronic liver cirrhosis incidence

Advanced liver cirrhosis has become life-threatening among non-communicable diseases nowadays.Cirrhosis,the terminal stage of liver diseases in which the liver develops scarring as a result of various long-term continuous damages.Among liver diseases,viral hepatitis is the major risk factor for chronic cirrhosis development.The present paper demonstrates a compartmental model of chronic disease liver cirrhosis describing the transmission dynamics of this disease.Applying the Pontryagin’s maximum principle,the optimal control policies such as vaccination for hepatitis B virus and treatment of other causes of cirrhosis are adopted as control measures.The target of this study is to minimize the number of infected and liver cirrhotic individuals as well as the associated cost of the control.For this purpose,the optimal control strategies are employed according to the underlying causes behind this disease.Our goal is to find the strategy of preventing hepatitis B infection which is considered one of the leading causes of cirrhosis and consequently,reduction of the chronic cirrhosis incidence.Efficiency analysis is also performed to observe the effective control among the two control strategies.The model is investigated both analytically and numerically and the numerical simulations are carried out to illustrate the analytical findings.The analysis reveals that both the vaccination and treatment could be the most fruitful way to reduce the incidence of chronic liver cirrhosis.

Evaluation of Transmission Losses of Various Battery Electric Vehicles

Transmission losses in battery electric vehicles have compared to internal combustion engine powertrains a larger share in the total energy consumption and play therefore a major role.Furthermore,the power flows not only during propulsion through the transmissions,but also during recuperation,whereby efficiency improvements have a double effect.The investigation of transmission losses of electric vehicles thus plays a major role.In this paper,three simulation models of the Institute of Automotive Engineering(the lossmap-based simulation model,the modular simulation model,and the 3D simulation model)are presented.The lossmap-based simulation model calculates transmission losses for electric and hybrid transmissions,where three spur gear transmission concepts for battery electric vehicles are investigated.The transmission concepts include a single-speed transmission as a reference and two two-speed transmissions.Then,the transmission lossmaps are integrated into the modular simulation model(backward simulation)and in the 3D simulation model(forward simulation),which improves the simulation results.The modular simulation model calculates the optimal operation of the transmission concepts and the 3D simulation model represents the more realistic behavior of the transmission concepts.The different transmission concepts are investigated in Worldwide Harmonized Light Vehicle Test Cycle and evaluated in terms of transmission losses as well as the total energy demand.The map-based simulation model allows the transmission losses to be broken down into the individual component losses,thus allowing transmission concepts to be examined and evaluated in terms of their efficiency in the early development stage to develop optimum powertrains for electric axle drives.By considering transmission losses in detail with a high degree of accuracy,less efficient concepts can be eliminated at an early development stage.As a result,only relevant concepts are built as prototypes,which reduces development costs.

Comprehensive Survey and Critical Evaluation of the Performance of State-of-the-art LED Drivers for Lighting Systems

The adoption of light-emitting diodes(LEDs)for lighting applications is becoming increasingly relevant as this recent technology is advancing.Given the recent uptake of LED lighting technologies for distinctive end-uses,the research community has also committed to the development of an ever-increasing range of power electronic converters that are suitable for yielding maximum quality lighting,high efficiency,and long lifetimes.As one of the most recent and promising technologies of the moment,it is vital to fully understand the performance and merits of each state-of-the-art LED lighting technology.Accordingly,this paper compiles essential information about a broad range of state-of-the-art LED lighting systems,aiming to compare their performances in terms of efficiency.Based on the comparative analysis,the main merits and drawbacks of each LED lighting system architecture are obtained.Then,a detailed evaluation of the performance of a particular LED lighting system and the corresponding control strategy is developed,thereby enabling a clear view of the evolution of the performance of the system as a function of parameters like supply voltage and number of driver channels.

Synthesis,characterization,and photocatalytic activity of porous La–N–co-doped TiO_2 nanotubes for gaseous chlorobenzene oxidation

The photocatalytic oxidation of gaseous chlorobenzene（CB） by the 365 nm-induced photocatalyst La/N–Ti O2, synthesized via a sol–gel and hydrothermal method, was evaluated. Response surface methodology（RSM） was used to model and optimize the conditions for synthesis of the photocatalyst. The optimal photocatalyst was 1.2La/0.5N–Ti O2（0.5） and the effects of La/N on crystalline structure, particle morphology, surface element content, and other structural characteristics were investigated by XRD（X-ray diffraction）, TEM（Transmission Electron Microscopy）, FTIR（Fourier transform infrared spectroscopy）, UV–vis（Ultraviolet–visible spectroscopy）, and BET（Brunauer Emmett Teller）. Greater surface area and smaller particle size were produced with the co-doped Ti O2 nanotubes than with reference Ti O2. The removal of CB was effective when performed using the synthesized photocatalyst,though it was less efficient at higher initial CB concentrations. Various modified Langmuir-Hinshelwood kinetic models involving the adsorption of chlorobenzene and water on different active sites were evaluated. Fitting results suggested that competitive adsorption caused by water molecules could not be neglected, especially for environments with high relative humidity. The reaction intermediates found after GC–MS（Gas chromatography–mass spectrometry） analysis indicated that most were soluble, low-toxicity, or both. The results demonstrated that the prepared photocatalyst had high activity for VOC（volatile organic compounds） conversion and may be used as a pretreatment prior to biopurification.