With the rise of remote collaboration,the demand for advanced storage and collaboration tools has rapidly increased.However,traditional collaboration tools primarily rely on access control,leaving data stored on cloud...With the rise of remote collaboration,the demand for advanced storage and collaboration tools has rapidly increased.However,traditional collaboration tools primarily rely on access control,leaving data stored on cloud servers vulnerable due to insufficient encryption.This paper introduces a novel mechanism that encrypts data in‘bundle’units,designed to meet the dual requirements of efficiency and security for frequently updated collaborative data.Each bundle includes updated information,allowing only the updated portions to be reencrypted when changes occur.The encryption method proposed in this paper addresses the inefficiencies of traditional encryption modes,such as Cipher Block Chaining(CBC)and Counter(CTR),which require decrypting and re-encrypting the entire dataset whenever updates occur.The proposed method leverages update-specific information embedded within data bundles and metadata that maps the relationship between these bundles and the plaintext data.By utilizing this information,the method accurately identifies the modified portions and applies algorithms to selectively re-encrypt only those sections.This approach significantly enhances the efficiency of data updates while maintaining high performance,particularly in large-scale data environments.To validate this approach,we conducted experiments measuring execution time as both the size of the modified data and the total dataset size varied.Results show that the proposed method significantly outperforms CBC and CTR modes in execution speed,with greater performance gains as data size increases.Additionally,our security evaluation confirms that this method provides robust protection against both passive and active attacks.展开更多
A new approach for prediction of face advance rete (FAR) prior to mining operation and determination of the operation efficiency after mining operation in retreat longwall mining panel is presented based upon the conc...A new approach for prediction of face advance rete (FAR) prior to mining operation and determination of the operation efficiency after mining operation in retreat longwall mining panel is presented based upon the concepts of rock engineering system (RES). For this purpose, six longwall panels considered in Parvadeh-I coal mine. Seven major effective parameters on FAR was selected including coal mine roof rating, gas propagation, safety factor of longwall face, ratio of joint spacing to cutting depth at longwall face, longwall face inclination, panel width, floor rock mass rating. To performance evaluation of the presented model, the relationship between the average vulnerability indexes of advance operation with FAR was determined in considered panels with coefficient of determination (R2) equal to 0.884 that indicate relatively acceptable correlation and compatibility. Investigations of the research indicated that it is possible to determine the actual operation efficiency under fair conditions by a RES-based model. The inevitable reduction of FAR for each longwall panel was determined by presented model that the difference amount between the maximum possible practical face advance rate (FARmpp) and recorded actual face advance rate (FARa) indicate the operation efficiency. Applied approach in this paper can be used to prediction of FAR in retreat longwall mining panel for same conditions that can have many benefits, including better and more accurate planning for the sales market and mine operation. Also, presented method in this paper can be applied as a useful tool to determination of actual operation efficiency for other sections and extraction methods in coal mines.展开更多
Solid oxide fuel cell combined with heat and power(SOFC-CHP)system is a distributed power generation system with low pollution and high efficiency.In this paper,a 10 kW SOFC-CHP system model using syngas was built in ...Solid oxide fuel cell combined with heat and power(SOFC-CHP)system is a distributed power generation system with low pollution and high efficiency.In this paper,a 10 kW SOFC-CHP system model using syngas was built in Aspen plus.Key operating parameters,such as steam to fuel ratio,stack temperature,reformer temperature,air flow rate,and air preheating temperature,were analyzed.Optimization was conducted based on the simulation results.Results suggest that higher steam to fuel ratio is beneficial to the electrical efficiency,but it might decrease the gross system efficiency.Higher stack and reformer temperatures contribute to the electrical efficiency,and the optimal operating temperatures of stack and reformer when considering the stack degradation are 750℃and 700℃,respectively.The air preheating temperature barely affects the electrical efficiency but affects the thermal efficiency and the gross system efficiency,the recommended value is around 600℃under the reference condition.展开更多
Gasification efficiency is an important factor that determines the actual technical operation as well as the economic viability of using a gasifier system for energy production. In this study, the impact of the physic...Gasification efficiency is an important factor that determines the actual technical operation as well as the economic viability of using a gasifier system for energy production. In this study, the impact of the physical properties of torrefied bagasse and the influence of gasifier design and operating variables were investigated in a computer simulated downdraft gasification system. Results obtained from the study indicated an interrelationship between feedstock characteristics, especially with regard to feed size, design variables such as throat angle and throat diameter as well as gasifier operating conditions such as temperature of input air and feed input. These variables influenced the efficiency of the gasification process of sugarcane bagasse because of increased enhancement of combustion zone reactions, which liberated huge amount of heat that led to a rise in the temperature of the gasification process. This condition also created increased tar cracking within the gasification system, contributing to reduction in the overall yield of tar.展开更多
The key to the healthy development of the market for green renovation of existing settlements lies in effectively playing the role of market resource allocation,and scientific evaluation of the current market operatio...The key to the healthy development of the market for green renovation of existing settlements lies in effectively playing the role of market resource allocation,and scientific evaluation of the current market operation efficiency is a prerequisite for the optimization and adjustment of market operation.Based on the perspective of market operation effectiveness,we start from the connotation and significance of the evaluation of the operation efficiency of the market of green renovation of existing settlements,construct the evaluation index system of the operation efficiency of the market of green renovation of existing settlements,use the hierarchical analysis method(AHP)and fuzzy comprehensive evaluation method(Fuzzy),establish the fuzzy comprehensive evaluation model,and finally,based on the operation process reengineering,financing model innovation,service platform expansion and market environment improvement,it structures the operation improvement path of the green renovation market of existing settlements and promotes the orderly operation of the green renovation market of existing settlements.展开更多
Metamorphic In0.55Ga0.45P/In0.06Ga0.94As/Ge triple-junction (3J-MM) solar cells are grown on Ge (100) sub- strates via metal organic chemical vapor deposition. Epi-structural analyses such as high resolution x-ray...Metamorphic In0.55Ga0.45P/In0.06Ga0.94As/Ge triple-junction (3J-MM) solar cells are grown on Ge (100) sub- strates via metal organic chemical vapor deposition. Epi-structural analyses such as high resolution x-ray diffrac- tion, photoluminence, cathodoluminescence and HRTEM are employed and the results show that the high crystal quality of 3J-MM solar cells is obtained with low threading dislocation density of graded buffer (an average value of 6.8× 10^4/cm2). Benefitting from the optimized bandgap combination, under one sun, AM0 spectrum, 25℃ conditions, the conversion efficiency is achieved about 32%, 5% higher compared with the lattice-matched In0.49Ga0.51P/In0.01Ga0.99As/Ge triple junction (3J-LM) solar cell. Under 1-MeV electron irradiation test, the degradation of the EQE and I-V characteristics of 3J-MM solar cells is at the same level as the 33-LM solar cell. The end-of-life efficiency is -27.1%. Therefore, the metamorphic triple-junction solar cell may be a promising candidate for next-generation space multi-junction solar cells.展开更多
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 impro...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.展开更多
Spine surgery is typically having a relationship to high degrees of pain and immobility.It is a known fact that the implementation of an enhanced recovery after surgery(ERAS)approach has led to a paradigm shift in var...Spine surgery is typically having a relationship to high degrees of pain and immobility.It is a known fact that the implementation of an enhanced recovery after surgery(ERAS)approach has led to a paradigm shift in various surgical specialties.These protocols require doctors,nurses,anesthesiologists,patients,and their families to agree to strengthen communication with each other,and involve a long timeline and teamwork from start to finish.To our knowledge,the role of nursing in the ERAS of spine surgery has not been reported before.The purpose of this study is to summarize the role of nursing in ERAS programs in accordance with surgical periods.The methods applied for this review include literature review of the world’s acknowledged databases such as Springer Link,PubMed,Embase,and Wanfang,especially in the period of 2000-2015.A total of 9 studies fulfilled the eligibility criteria and were included in the review.The findings confirm that the nursing work continued throughout the perioperative procedure,which plays a key role in the successful ERAS pathway.According to different nursing measures,ERAS nursing can effectively promote the postoperative recovery of spine surgical patients,with fewer postoperative complications and increased patient satisfaction.展开更多
We view a facility system as a kind of supply chain and model it as a connected graph in which the nodes represent suppliers, distribution centers or customers and the edges represent the paths of goods or information...We view a facility system as a kind of supply chain and model it as a connected graph in which the nodes represent suppliers, distribution centers or customers and the edges represent the paths of goods or information. The efficiency, and hence the reliability, of a facility system is to a large degree adversely affected by the edge failures in the network. In this paper, we consider facility systems' reliability analysis based on the classical p-median problem when subject to edge failures. We formulate two models based on deterministic case and stochastic case to measure the loss in efficiency due to edge failures and give computational results and reliability envelopes for a specific example.展开更多
The advancement of science and technology has introduced the concept of big data, which has significantly transformed the business management environment of enterprises. Currently, most administrative tasks in compani...The advancement of science and technology has introduced the concept of big data, which has significantly transformed the business management environment of enterprises. Currently, most administrative tasks in companies heavily rely on human resources, with skilled management staff using their expertise to oversee business operations. However, this approach is susceptible to human subjective biases. The method assists managers in formulating efficient strategies for implementing management measures and enhancing the effectiveness of production, sales, financial, and people organization structure management. This ultimately leads to a more evidence-based approach to corporate management. This technique expands the utilization of Web services from a strategy focused on integrating services to a comprehensive framework for Service-Oriented Computing (SOC). The primary focus is implementing WS-session to manage sessions in general Web services applications, defining a bidirectional entire duplex interface for communication in Web services, and developing the Web Services Initiation Protocol, presenting WIP, a thorough multimedia and voice communication framework constructed using Web services and Service-Oriented Architecture (SOA). The office automation management system, created utilizing ASP.net and SQL Server technology, encompasses the evaluation of viability, analysis of needs, and system design. Office automation refers to using equipment with computing capabilities to carry out various office tasks and utilize associated tools and applications. Office automation uses computer-based systems to collect, organize, and modify visual and auditory information to enhance business energy efficiency and time management. Office automation refers to auto-mating essential tasks employees perform, including identification, automatic appointment reminders, and automatic power management for personal computers. The employee image is obtained through the utilization of the Java media framework. Attendance data for all employees are collected and methodically examined. The database enables the retrieval of these records monthly or weekly. An office automation system offers organizations enhanced features for managing office information, significantly improving office efficiency and quality. Moreover, it improves office administration and decision-making procedures by automating and strengthening the scientific elements of office functions. The ongoing progress of organizational information technology has led to a strong focus on sharing information resources in scientific research initiatives. Conventional firms exhibit intricate company processes, inadequate managerial efficacy, and unnecessarily elevated operational expenses, resulting in diminished competitiveness. Thus, using an ERP management system is the optimal decision for organizations to restore their crucial competitive advantage. This technology enhances their operational methods, streamlines their operations, and enhances transparency in their operational approaches. The system comprises six modules: buy plan, purchase order, purchase contract, purchase document inquiry, purchase to order, and purchase return. These modules effectively meet the operational needs of enterprises.展开更多
The data envelopment analysis (DEA) is used to evaluate operation efficiency of 17 listed companies in China aviation industry from 2006 to 2011, and make longitudinal analysis for the operation efficiency. In addit...The data envelopment analysis (DEA) is used to evaluate operation efficiency of 17 listed companies in China aviation industry from 2006 to 2011, and make longitudinal analysis for the operation efficiency. In addition, the reason of changing efficiency is dynamically evaluated by Malmquist productivity index. The empirical results show that average operation efficiency of 17 listed companies in China aviation industry is less than 1, which means that the operation activities of aviation industry exist diseconomies characteristic, technological progress efficiency is a major influenced factor展开更多
Purpose: This study aimed to enhance the prediction of container dwell time, a crucial factor for optimizing port operations, resource allocation, and supply chain efficiency. Determining an optimal learning rate for ...Purpose: This study aimed to enhance the prediction of container dwell time, a crucial factor for optimizing port operations, resource allocation, and supply chain efficiency. Determining an optimal learning rate for training Artificial Neural Networks (ANNs) has remained a challenging task due to the diverse sizes, complexity, and types of data involved. Design/Method/Approach: This research used a RandomizedSearchCV algorithm, a random search approach, to bridge this knowledge gap. The algorithm was applied to container dwell time data from the TOS system of the Port of Tema, which included 307,594 container records from 2014 to 2022. Findings: The RandomizedSearchCV method outperformed standard training methods both in terms of reducing training time and improving prediction accuracy, highlighting the significant role of the constant learning rate as a hyperparameter. Research Limitations and Implications: Although the study provides promising outcomes, the results are limited to the data extracted from the Port of Tema and may differ in other contexts. Further research is needed to generalize these findings across various port systems. Originality/Value: This research underscores the potential of RandomizedSearchCV as a valuable tool for optimizing ANN training in container dwell time prediction. It also accentuates the significance of automated learning rate selection, offering novel insights into the optimization of container dwell time prediction, with implications for improving port efficiency and supply chain operations.展开更多
We report that a novel exciton feedback effect is observed by introducing the bis(2-methyl-8-quinolinolato)(4- phenylphenolato)Muminum (BAlq) inserted between the emitting layer (EML) and the electron transpor...We report that a novel exciton feedback effect is observed by introducing the bis(2-methyl-8-quinolinolato)(4- phenylphenolato)Muminum (BAlq) inserted between the emitting layer (EML) and the electron transporting layer in blue organic light emitting diodes. As an exciton feedback layer (EFL), the BAlq does not act as a traditional hole blocking effect. The design of this kind of device structure can greatly reduce excitons' quenching due to accumulated space charge at the exciton formation interface. Meanwhile, the non-radiative energy transfer from EFL to the EML can also be utilized to enhance the excitons' formation, which is confirmed by the test of photolumimescent transient lifetime decay and electroluminescence enhancement of these devices. Accordingly, the optimal device presents the improved performances with the maximum current efficiency of 4.2 cd/A and the luminance of 24600cd/m2, which are about 1.45 times and 1.75 times higher than those of device A (control device) without the EFL, respectively. Simultaneously, the device shows an excellent color stability with a tiny offset of the CIE coordinates (△x = ±0.003, △y = ±0.004) and a relatively lower efficiency roll-off of 26.2% under the driving voltage varying from 3 V to 10 V.展开更多
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.Fir...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.展开更多
This paper studies the vapor pressure of water and precipitation situation in Lu'an Ground Station in Dabie Mountain area from 1979 to 1998.And the atmospheric perceivable water in Dabie Mountain can be calculated...This paper studies the vapor pressure of water and precipitation situation in Lu'an Ground Station in Dabie Mountain area from 1979 to 1998.And the atmospheric perceivable water in Dabie Mountain can be calculated by virtue of the empirical formula for atmospheric perceivable water.Besides,by analyzing the data,the seasonal changes of perceivable water in Dabie Mountain and the efficiency of precipitation of each weather system is acquired.The results show that there is a great potential for precipitation enhancement in Dabie Mountain.This paper introduces the processes and operation forms of precipitation enhancement for impounding water in reservoirs in Dabie Mountain region.展开更多
The development of more adequate food programs regarding the intensity and duration of the restriction can be an effective way to minimize the effects of exaggerated food consumption and its negative consequences for ...The development of more adequate food programs regarding the intensity and duration of the restriction can be an effective way to minimize the effects of exaggerated food consumption and its negative consequences for the economy of the business.In this sense,juvenile Nile tilapia(Oreochromis niloticus)(137±3 g)were submitted to different feeding strategies in a recirculation system.Five feeding strategies were tested in subsequent weekly cycles:continuous feeding;skipping one meal a week;suppression of two non-consecutive meals a week;suppression of three non-consecutive meals a week;suppression of four non-consecutive meals a week.Productive performance,feed consumption in the post-restriction period and economic indicators were evaluated through projections and profitability analyses.Compensatory intake occurred in all tested groups,so that the total feed intake(FI)did not differ significantly between them(p>0.05).Moderate food restriction provided a linear increase in the relative gross margin for each treatment with each change in salary level,as well as greater profitability when compared to the respective control group(p<0.05).展开更多
The data of the analytical estimation on the efficiency of providing safety control of the radioelectronic system are given.The review is based on the investigation of the information interaction of the radio-electron...The data of the analytical estimation on the efficiency of providing safety control of the radioelectronic system are given.The review is based on the investigation of the information interaction of the radio-electronic system(RS)with monitoring subsystem.The problem of optimal safety operational subsystem control of the RS and the generalized criterion for the effectiveness of decision making by the control system of the RS are formulated.Analytical expressions that allow making the choice of optimal ratio between the safe and the most effective modes of the control system operation are obtained.展开更多
With the implementation of China’s reform and opening up policy and China’s successful accession to the World Trade Organization,more and more overseas financial institutions are participating in various Chinese ban...With the implementation of China’s reform and opening up policy and China’s successful accession to the World Trade Organization,more and more overseas financial institutions are participating in various Chinese banks,and the amount of investment is also expanding.Therefore,it is particularly important to study the impact of overseas financial institutions participating in the Chinese Banks on the operating efficiency of the China’s banking industry.Therefore,based on the previous literature research,this paper constructs six models to explore whether foreign financial institutions participate in shares and the impact of shareholding ratio on the operating efficiency of China’s banking industry.展开更多
BACKGROUND Fascia iliaca compartment blocks(FIBs) have been used to provide postoperative analgesia after total hip arthroplasty(THA). However, evidence of their efficacy remains limited. While pain control appears to...BACKGROUND Fascia iliaca compartment blocks(FIBs) have been used to provide postoperative analgesia after total hip arthroplasty(THA). However, evidence of their efficacy remains limited. While pain control appears to be satisfactory, quadriceps weakness may be an untoward consequence of the block. Prior studies have shown femoral nerve blocks and fascia iliaca blocks as being superior for pain control and ambulation following THA when compared to standard therapy of parenteral pain control. However, most studies allowed patients to ambulate on post-operative day(POD) 2-3, whereas new guidelines suggest ambulation on POD 0 is beneficial.AIM To determine the effect of FIB after THA in patients participating in an enhanced recovery after surgery(ERAS) program.METHODS We conducted a retrospective analysis of patients undergoing THA with or without FICBs and their ability to ambulate on POD 0 in accordance with ERAS protocol. Perioperative data was collected on 39 patients who underwent THA.Demographic data, anesthesia data, and ambulatory outcomes were compared.RESULTS Twenty patients had FIBs placed at the conclusion of the procedure, while 19 did not receive a block. Of the 20 patients with FIB, only 1 patient was able to ambulate. Of the 19 patients without FIB blocks, 17 were able to ambulate. All patients worked with physical therapy 2 h after arriving in the post-anesthesia care unit on POD 0.CONCLUSION Our data suggests an association between FIB and delayed ambulation in the immediate post-operative period.展开更多
Organic–inorganic hybrid perovskites play an important role in improving the efficiency of solid-state dye-sensitized solar cells. In this paper, we systematically explore the efficiency-enhancing mechanism of ABX_3...Organic–inorganic hybrid perovskites play an important role in improving the efficiency of solid-state dye-sensitized solar cells. In this paper, we systematically explore the efficiency-enhancing mechanism of ABX_3(A = CH_3NH_3; B = Sn,Pb; X = Cl, Br, I) and provide the best absorber among ABX_3 when the organic framework A is CH_3NH_3 by first-principles calculations. The results reveal that the valence band maximum(VBM) of the ABX_3 is mainly composed of anion X p states and that conduction band minimum(CBM) of the ABX_3 is primarily composed of cation B p states. The bandgap of the ABX_3 decreases and the absorptive capacities of different wavelengths of light expand when reducing the size of the organic framework A, changing the B atom from Pb to Sn, and changing the X atom from Cl to Br to I. Finally, based on our calculations, it is discovered that CH_3NH_3 Sn I_3has the best optical properties and its light-adsorption range is the widest among all the ABX_3 compounds when A is CH_3NH_3. All these results indicate that the electronegativity difference between X and B plays a fundamental role in changing the energy gap and optical properties among ABX_3 compounds when A remains the same and that CH_3NH_3 Sn I_3 is a promising perovskite absorber in the high efficiency solar batteries among all the CH_3NH_3BX_3 compounds.展开更多
基金supported by the Institute of Information&communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(RS-2024-00399401,Development of Quantum-Safe Infrastructure Migration and Quantum Security Verification Technologies).
文摘With the rise of remote collaboration,the demand for advanced storage and collaboration tools has rapidly increased.However,traditional collaboration tools primarily rely on access control,leaving data stored on cloud servers vulnerable due to insufficient encryption.This paper introduces a novel mechanism that encrypts data in‘bundle’units,designed to meet the dual requirements of efficiency and security for frequently updated collaborative data.Each bundle includes updated information,allowing only the updated portions to be reencrypted when changes occur.The encryption method proposed in this paper addresses the inefficiencies of traditional encryption modes,such as Cipher Block Chaining(CBC)and Counter(CTR),which require decrypting and re-encrypting the entire dataset whenever updates occur.The proposed method leverages update-specific information embedded within data bundles and metadata that maps the relationship between these bundles and the plaintext data.By utilizing this information,the method accurately identifies the modified portions and applies algorithms to selectively re-encrypt only those sections.This approach significantly enhances the efficiency of data updates while maintaining high performance,particularly in large-scale data environments.To validate this approach,we conducted experiments measuring execution time as both the size of the modified data and the total dataset size varied.Results show that the proposed method significantly outperforms CBC and CTR modes in execution speed,with greater performance gains as data size increases.Additionally,our security evaluation confirms that this method provides robust protection against both passive and active attacks.
文摘A new approach for prediction of face advance rete (FAR) prior to mining operation and determination of the operation efficiency after mining operation in retreat longwall mining panel is presented based upon the concepts of rock engineering system (RES). For this purpose, six longwall panels considered in Parvadeh-I coal mine. Seven major effective parameters on FAR was selected including coal mine roof rating, gas propagation, safety factor of longwall face, ratio of joint spacing to cutting depth at longwall face, longwall face inclination, panel width, floor rock mass rating. To performance evaluation of the presented model, the relationship between the average vulnerability indexes of advance operation with FAR was determined in considered panels with coefficient of determination (R2) equal to 0.884 that indicate relatively acceptable correlation and compatibility. Investigations of the research indicated that it is possible to determine the actual operation efficiency under fair conditions by a RES-based model. The inevitable reduction of FAR for each longwall panel was determined by presented model that the difference amount between the maximum possible practical face advance rate (FARmpp) and recorded actual face advance rate (FARa) indicate the operation efficiency. Applied approach in this paper can be used to prediction of FAR in retreat longwall mining panel for same conditions that can have many benefits, including better and more accurate planning for the sales market and mine operation. Also, presented method in this paper can be applied as a useful tool to determination of actual operation efficiency for other sections and extraction methods in coal mines.
基金the National Key R&D Program of China(2017YFB0601903).
文摘Solid oxide fuel cell combined with heat and power(SOFC-CHP)system is a distributed power generation system with low pollution and high efficiency.In this paper,a 10 kW SOFC-CHP system model using syngas was built in Aspen plus.Key operating parameters,such as steam to fuel ratio,stack temperature,reformer temperature,air flow rate,and air preheating temperature,were analyzed.Optimization was conducted based on the simulation results.Results suggest that higher steam to fuel ratio is beneficial to the electrical efficiency,but it might decrease the gross system efficiency.Higher stack and reformer temperatures contribute to the electrical efficiency,and the optimal operating temperatures of stack and reformer when considering the stack degradation are 750℃and 700℃,respectively.The air preheating temperature barely affects the electrical efficiency but affects the thermal efficiency and the gross system efficiency,the recommended value is around 600℃under the reference condition.
文摘Gasification efficiency is an important factor that determines the actual technical operation as well as the economic viability of using a gasifier system for energy production. In this study, the impact of the physical properties of torrefied bagasse and the influence of gasifier design and operating variables were investigated in a computer simulated downdraft gasification system. Results obtained from the study indicated an interrelationship between feedstock characteristics, especially with regard to feed size, design variables such as throat angle and throat diameter as well as gasifier operating conditions such as temperature of input air and feed input. These variables influenced the efficiency of the gasification process of sugarcane bagasse because of increased enhancement of combustion zone reactions, which liberated huge amount of heat that led to a rise in the temperature of the gasification process. This condition also created increased tar cracking within the gasification system, contributing to reduction in the overall yield of tar.
基金supported by the National Natural Science Foundation of China(Grant No.71872122)the Late-stage Subsidy Project of Humanities and Social Sciences of the Education Department of China(Grant No.20JHQ095).
文摘The key to the healthy development of the market for green renovation of existing settlements lies in effectively playing the role of market resource allocation,and scientific evaluation of the current market operation efficiency is a prerequisite for the optimization and adjustment of market operation.Based on the perspective of market operation effectiveness,we start from the connotation and significance of the evaluation of the operation efficiency of the market of green renovation of existing settlements,construct the evaluation index system of the operation efficiency of the market of green renovation of existing settlements,use the hierarchical analysis method(AHP)and fuzzy comprehensive evaluation method(Fuzzy),establish the fuzzy comprehensive evaluation model,and finally,based on the operation process reengineering,financing model innovation,service platform expansion and market environment improvement,it structures the operation improvement path of the green renovation market of existing settlements and promotes the orderly operation of the green renovation market of existing settlements.
基金Supported by the Grand from Tianjin Little Giant Fund under Grant No 14ZXLJGX00400the Tianjin Science and Technology Support Plan under Grant No 16YFZCGX00030
文摘Metamorphic In0.55Ga0.45P/In0.06Ga0.94As/Ge triple-junction (3J-MM) solar cells are grown on Ge (100) sub- strates via metal organic chemical vapor deposition. Epi-structural analyses such as high resolution x-ray diffrac- tion, photoluminence, cathodoluminescence and HRTEM are employed and the results show that the high crystal quality of 3J-MM solar cells is obtained with low threading dislocation density of graded buffer (an average value of 6.8× 10^4/cm2). Benefitting from the optimized bandgap combination, under one sun, AM0 spectrum, 25℃ conditions, the conversion efficiency is achieved about 32%, 5% higher compared with the lattice-matched In0.49Ga0.51P/In0.01Ga0.99As/Ge triple junction (3J-LM) solar cell. Under 1-MeV electron irradiation test, the degradation of the EQE and I-V characteristics of 3J-MM solar cells is at the same level as the 33-LM solar cell. The end-of-life efficiency is -27.1%. Therefore, the metamorphic triple-junction solar cell may be a promising candidate for next-generation space multi-junction solar cells.
文摘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.
基金sponsored by the scientific research and technology development plan of Nanning(20193100,Z20191065,Z20190446)Nanning Excellent Young Scientist Program RC20200102.
文摘Spine surgery is typically having a relationship to high degrees of pain and immobility.It is a known fact that the implementation of an enhanced recovery after surgery(ERAS)approach has led to a paradigm shift in various surgical specialties.These protocols require doctors,nurses,anesthesiologists,patients,and their families to agree to strengthen communication with each other,and involve a long timeline and teamwork from start to finish.To our knowledge,the role of nursing in the ERAS of spine surgery has not been reported before.The purpose of this study is to summarize the role of nursing in ERAS programs in accordance with surgical periods.The methods applied for this review include literature review of the world’s acknowledged databases such as Springer Link,PubMed,Embase,and Wanfang,especially in the period of 2000-2015.A total of 9 studies fulfilled the eligibility criteria and were included in the review.The findings confirm that the nursing work continued throughout the perioperative procedure,which plays a key role in the successful ERAS pathway.According to different nursing measures,ERAS nursing can effectively promote the postoperative recovery of spine surgical patients,with fewer postoperative complications and increased patient satisfaction.
文摘We view a facility system as a kind of supply chain and model it as a connected graph in which the nodes represent suppliers, distribution centers or customers and the edges represent the paths of goods or information. The efficiency, and hence the reliability, of a facility system is to a large degree adversely affected by the edge failures in the network. In this paper, we consider facility systems' reliability analysis based on the classical p-median problem when subject to edge failures. We formulate two models based on deterministic case and stochastic case to measure the loss in efficiency due to edge failures and give computational results and reliability envelopes for a specific example.
文摘The advancement of science and technology has introduced the concept of big data, which has significantly transformed the business management environment of enterprises. Currently, most administrative tasks in companies heavily rely on human resources, with skilled management staff using their expertise to oversee business operations. However, this approach is susceptible to human subjective biases. The method assists managers in formulating efficient strategies for implementing management measures and enhancing the effectiveness of production, sales, financial, and people organization structure management. This ultimately leads to a more evidence-based approach to corporate management. This technique expands the utilization of Web services from a strategy focused on integrating services to a comprehensive framework for Service-Oriented Computing (SOC). The primary focus is implementing WS-session to manage sessions in general Web services applications, defining a bidirectional entire duplex interface for communication in Web services, and developing the Web Services Initiation Protocol, presenting WIP, a thorough multimedia and voice communication framework constructed using Web services and Service-Oriented Architecture (SOA). The office automation management system, created utilizing ASP.net and SQL Server technology, encompasses the evaluation of viability, analysis of needs, and system design. Office automation refers to using equipment with computing capabilities to carry out various office tasks and utilize associated tools and applications. Office automation uses computer-based systems to collect, organize, and modify visual and auditory information to enhance business energy efficiency and time management. Office automation refers to auto-mating essential tasks employees perform, including identification, automatic appointment reminders, and automatic power management for personal computers. The employee image is obtained through the utilization of the Java media framework. Attendance data for all employees are collected and methodically examined. The database enables the retrieval of these records monthly or weekly. An office automation system offers organizations enhanced features for managing office information, significantly improving office efficiency and quality. Moreover, it improves office administration and decision-making procedures by automating and strengthening the scientific elements of office functions. The ongoing progress of organizational information technology has led to a strong focus on sharing information resources in scientific research initiatives. Conventional firms exhibit intricate company processes, inadequate managerial efficacy, and unnecessarily elevated operational expenses, resulting in diminished competitiveness. Thus, using an ERP management system is the optimal decision for organizations to restore their crucial competitive advantage. This technology enhances their operational methods, streamlines their operations, and enhances transparency in their operational approaches. The system comprises six modules: buy plan, purchase order, purchase contract, purchase document inquiry, purchase to order, and purchase return. These modules effectively meet the operational needs of enterprises.
基金supported by the Humanities and Social Science Foundation of the Chinese Ministry of Education under Grant No.09YJA630133
文摘The data envelopment analysis (DEA) is used to evaluate operation efficiency of 17 listed companies in China aviation industry from 2006 to 2011, and make longitudinal analysis for the operation efficiency. In addition, the reason of changing efficiency is dynamically evaluated by Malmquist productivity index. The empirical results show that average operation efficiency of 17 listed companies in China aviation industry is less than 1, which means that the operation activities of aviation industry exist diseconomies characteristic, technological progress efficiency is a major influenced factor
文摘Purpose: This study aimed to enhance the prediction of container dwell time, a crucial factor for optimizing port operations, resource allocation, and supply chain efficiency. Determining an optimal learning rate for training Artificial Neural Networks (ANNs) has remained a challenging task due to the diverse sizes, complexity, and types of data involved. Design/Method/Approach: This research used a RandomizedSearchCV algorithm, a random search approach, to bridge this knowledge gap. The algorithm was applied to container dwell time data from the TOS system of the Port of Tema, which included 307,594 container records from 2014 to 2022. Findings: The RandomizedSearchCV method outperformed standard training methods both in terms of reducing training time and improving prediction accuracy, highlighting the significant role of the constant learning rate as a hyperparameter. Research Limitations and Implications: Although the study provides promising outcomes, the results are limited to the data extracted from the Port of Tema and may differ in other contexts. Further research is needed to generalize these findings across various port systems. Originality/Value: This research underscores the potential of RandomizedSearchCV as a valuable tool for optimizing ANN training in container dwell time prediction. It also accentuates the significance of automated learning rate selection, offering novel insights into the optimization of container dwell time prediction, with implications for improving port efficiency and supply chain operations.
基金Supported by the National Natural Science Foundation of China under Grant No 60906022the Natural Science Foundation of Tianjin under Grant No 10JCYBJC01100+1 种基金the Scientific Developing Foundation of Tianjin Education Commission under Grant No 2011ZD02the Key Science and Technology Support Program of Tianjin under Grant No 14ZCZDGX00006
文摘We report that a novel exciton feedback effect is observed by introducing the bis(2-methyl-8-quinolinolato)(4- phenylphenolato)Muminum (BAlq) inserted between the emitting layer (EML) and the electron transporting layer in blue organic light emitting diodes. As an exciton feedback layer (EFL), the BAlq does not act as a traditional hole blocking effect. The design of this kind of device structure can greatly reduce excitons' quenching due to accumulated space charge at the exciton formation interface. Meanwhile, the non-radiative energy transfer from EFL to the EML can also be utilized to enhance the excitons' formation, which is confirmed by the test of photolumimescent transient lifetime decay and electroluminescence enhancement of these devices. Accordingly, the optimal device presents the improved performances with the maximum current efficiency of 4.2 cd/A and the luminance of 24600cd/m2, which are about 1.45 times and 1.75 times higher than those of device A (control device) without the EFL, respectively. Simultaneously, the device shows an excellent color stability with a tiny offset of the CIE coordinates (△x = ±0.003, △y = ±0.004) and a relatively lower efficiency roll-off of 26.2% under the driving voltage varying from 3 V to 10 V.
文摘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.
基金Supported by China Meteorological Administration (Provincial Figure Operation System Based on the New Generation Radar)The Program of Experimental Investigation on the Development and Utilization of Aerial Cloud Resource in Anhui Province
文摘This paper studies the vapor pressure of water and precipitation situation in Lu'an Ground Station in Dabie Mountain area from 1979 to 1998.And the atmospheric perceivable water in Dabie Mountain can be calculated by virtue of the empirical formula for atmospheric perceivable water.Besides,by analyzing the data,the seasonal changes of perceivable water in Dabie Mountain and the efficiency of precipitation of each weather system is acquired.The results show that there is a great potential for precipitation enhancement in Dabie Mountain.This paper introduces the processes and operation forms of precipitation enhancement for impounding water in reservoirs in Dabie Mountain region.
文摘The development of more adequate food programs regarding the intensity and duration of the restriction can be an effective way to minimize the effects of exaggerated food consumption and its negative consequences for the economy of the business.In this sense,juvenile Nile tilapia(Oreochromis niloticus)(137±3 g)were submitted to different feeding strategies in a recirculation system.Five feeding strategies were tested in subsequent weekly cycles:continuous feeding;skipping one meal a week;suppression of two non-consecutive meals a week;suppression of three non-consecutive meals a week;suppression of four non-consecutive meals a week.Productive performance,feed consumption in the post-restriction period and economic indicators were evaluated through projections and profitability analyses.Compensatory intake occurred in all tested groups,so that the total feed intake(FI)did not differ significantly between them(p>0.05).Moderate food restriction provided a linear increase in the relative gross margin for each treatment with each change in salary level,as well as greater profitability when compared to the respective control group(p<0.05).
文摘The data of the analytical estimation on the efficiency of providing safety control of the radioelectronic system are given.The review is based on the investigation of the information interaction of the radio-electronic system(RS)with monitoring subsystem.The problem of optimal safety operational subsystem control of the RS and the generalized criterion for the effectiveness of decision making by the control system of the RS are formulated.Analytical expressions that allow making the choice of optimal ratio between the safe and the most effective modes of the control system operation are obtained.
文摘With the implementation of China’s reform and opening up policy and China’s successful accession to the World Trade Organization,more and more overseas financial institutions are participating in various Chinese banks,and the amount of investment is also expanding.Therefore,it is particularly important to study the impact of overseas financial institutions participating in the Chinese Banks on the operating efficiency of the China’s banking industry.Therefore,based on the previous literature research,this paper constructs six models to explore whether foreign financial institutions participate in shares and the impact of shareholding ratio on the operating efficiency of China’s banking industry.
文摘BACKGROUND Fascia iliaca compartment blocks(FIBs) have been used to provide postoperative analgesia after total hip arthroplasty(THA). However, evidence of their efficacy remains limited. While pain control appears to be satisfactory, quadriceps weakness may be an untoward consequence of the block. Prior studies have shown femoral nerve blocks and fascia iliaca blocks as being superior for pain control and ambulation following THA when compared to standard therapy of parenteral pain control. However, most studies allowed patients to ambulate on post-operative day(POD) 2-3, whereas new guidelines suggest ambulation on POD 0 is beneficial.AIM To determine the effect of FIB after THA in patients participating in an enhanced recovery after surgery(ERAS) program.METHODS We conducted a retrospective analysis of patients undergoing THA with or without FICBs and their ability to ambulate on POD 0 in accordance with ERAS protocol. Perioperative data was collected on 39 patients who underwent THA.Demographic data, anesthesia data, and ambulatory outcomes were compared.RESULTS Twenty patients had FIBs placed at the conclusion of the procedure, while 19 did not receive a block. Of the 20 patients with FIB, only 1 patient was able to ambulate. Of the 19 patients without FIB blocks, 17 were able to ambulate. All patients worked with physical therapy 2 h after arriving in the post-anesthesia care unit on POD 0.CONCLUSION Our data suggests an association between FIB and delayed ambulation in the immediate post-operative period.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61366007,11164032,and 61066005)the Program for New Century Excellent Talents in University of Ministry of Education of China(Grant No.NCET-12-1080)+1 种基金the Basic Applied Research Foundation of Yunnan Province,China(Grant Nos.2011CI003 and 2013FB007)the Excellent Young Talents in Yunnan University,China
文摘Organic–inorganic hybrid perovskites play an important role in improving the efficiency of solid-state dye-sensitized solar cells. In this paper, we systematically explore the efficiency-enhancing mechanism of ABX_3(A = CH_3NH_3; B = Sn,Pb; X = Cl, Br, I) and provide the best absorber among ABX_3 when the organic framework A is CH_3NH_3 by first-principles calculations. The results reveal that the valence band maximum(VBM) of the ABX_3 is mainly composed of anion X p states and that conduction band minimum(CBM) of the ABX_3 is primarily composed of cation B p states. The bandgap of the ABX_3 decreases and the absorptive capacities of different wavelengths of light expand when reducing the size of the organic framework A, changing the B atom from Pb to Sn, and changing the X atom from Cl to Br to I. Finally, based on our calculations, it is discovered that CH_3NH_3 Sn I_3has the best optical properties and its light-adsorption range is the widest among all the ABX_3 compounds when A is CH_3NH_3. All these results indicate that the electronegativity difference between X and B plays a fundamental role in changing the energy gap and optical properties among ABX_3 compounds when A remains the same and that CH_3NH_3 Sn I_3 is a promising perovskite absorber in the high efficiency solar batteries among all the CH_3NH_3BX_3 compounds.