State departments of transportation’s (DOTs) decisions to invest resources to expand or implement intelligent transportation systems (ITS) programs or even retire existing infrastructure need to be based on performan...State departments of transportation’s (DOTs) decisions to invest resources to expand or implement intelligent transportation systems (ITS) programs or even retire existing infrastructure need to be based on performance evaluations. Nonetheless, an apparent gap exists between the need for ITS performance measurements and the actual implementation. The evidence available points to challenges in the ITS performance measurement processes. This paper evaluated the state of practice of performance measurement for ITS across the US and provided insights. A comprehensive literature review assessed the use of performance measures by DOTs for monitoring implemented ITS programs. Based on the gaps identified through the literature review, a nationwide qualitative survey was used to gather insights from key stakeholders on the subject matter and presented in this paper. From the data gathered, performance measurement of ITS is fairly integrated into ITS programs by DOTs, with most agencies considering the process beneficial. There, however, exist reasons that prevent agencies from measuring ITS performance to greater detail and quality. These include lack of data, fragmented or incomparable data formats, the complexity of the endeavor, lack of data scientists, and difficulty assigning responsibilities when inter-agency collaboration is required. Additionally, DOTs do not benchmark or compare their ITS performance with others for reasons that include lack of data, lack of guidance or best practices, and incomparable data formats. This paper is relevant as it provides insights expected to guide DOTs and other agencies in developing or reevaluating their ITS performance measurement processes.展开更多
Emerging connected vehicle (CV) data sets have recently become commercially available, enabling analysts to develop a variety of powerful performance measures without deploying any field infrastructure. This paper pre...Emerging connected vehicle (CV) data sets have recently become commercially available, enabling analysts to develop a variety of powerful performance measures without deploying any field infrastructure. This paper presents several tools using CV data to evaluate traffic progression quality along a signalized corridor. These include both performance measures for high-level analysis as well as visualizations to examine details of the coordinated operation. With the use of CV data, it is possible to assess not only the movement of traffic on the corridor but also to consider its origin-destination (O-D) path through the corridor. Results for the real-world operation of an eight-intersection signalized arterial are presented. A series of high-level performance measures are used to evaluate overall performance by time of day, with differing results by metric. Next, the details of the operation are examined with the use of two visualization tools: a cyclic time-space diagram (TSD) and an empirical platoon progression diagram (PPD). Comparing flow visualizations developed with different included O-D paths reveals several features, such as the presence of secondary and tertiary platoons on certain sections that cannot be seen when only end-to-end journeys are included. In addition, speed heat maps are generated, providing both speed performance along the corridor and locations and the extent of the queue. The proposed visualization tools portray the corridor’s performance holistically instead of combining individual signal performance metrics. The techniques exhibited in this study are compelling for identifying locations where engineering solutions such as access management or timing plan change are required. The recent progress in infrastructure-free sensing technology has significantly increased the scope of CV data-based traffic management systems, enhancing the significance of this study. The study demonstrates the utility of CV trajectory data for obtaining high-level details of the corridor performance as well as drilling down into the minute specifics.展开更多
Large diameter fans with low solidity are widely used in automotive application for engine cooling. Their designs with small chord length help reducing the torque on the electrical motor and providing a good aerodynam...Large diameter fans with low solidity are widely used in automotive application for engine cooling. Their designs with small chord length help reducing the torque on the electrical motor and providing a good aerodynamic compromise between several operating conditions, some of these being at high flow rate. Their global performances are measured according to the ISO standard DP 5801, which allows comparison of results from different facilities. However, some variations in global performances are observed when considering results from two different test rigs. On a fan selected for the purpose of this study, up to 6 % of efficiency is lost on the worst case. As efficiency is more than ever a key factor to select a component, some experimental and numerical investigations were conducted to analyze the fan behavior on each facility. Two sets of measurement and simulation are performed and compared. Geometries considered for the domain of computation include the test rig plenum, the torquemeter, the ground and a large domain for the atmospheric conditions. The exact fan geometry with tip clearance and under-hub ribs is also considered. Numerical results show a good agreement with experiment in both cases when convergence is reached and for low flow rate when computations are switched to unsteady mode. Comparisons show that simulations are able to capture the different fan behaviors depending on the confguration and those efficiency losses previously observed are correctly predicted. These results are further analyzed to perform some post-processing. Blade loading remains identical for both cases but disparities appear in the wake and its interaction with the surrounding. Tiny details that are often neglected during experiment and/or simulation appear to be the cause of slight variations. Position of the torquemeter and shape of the plenum are among the parameters that various and that have cumulative effects. Efficiency being a ration of pressure and torque, variations are rather important. Finally, these results are discussed in terms of rules for conception and a new geometry less sensible to loss of efficiency is proposed.展开更多
Fuzzy cognitive maps (FCM) is a well-established artificial intelligence technique, which can be effectively applied in the domains of performance measurement, decision making and other management science. FCM can b...Fuzzy cognitive maps (FCM) is a well-established artificial intelligence technique, which can be effectively applied in the domains of performance measurement, decision making and other management science. FCM can be a useful tool in a group decision-making environment by using scientifically integrated expert knowledge. The theories of FCM and balance scorecard (BSC) both emphasize cause-and-effect relationships among indicators in a complex system, but few reports have been published addressing the combined application of these two techniques. In this paper we propose a FCM simulation model for the sample performance measurement system of Intemet-based supply chain, which is constructed by BSC theory. We gave examples to explain how FCM can be adapted to execute the causal mechanism of BSC, and also how FCM can support group decision-making and forecasting in performance measurement.展开更多
The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2...The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2T link would reduce the headway and improve operational efficiency.Formal methods are system design techniques that use rigorously specified mathematical models to ensure all behaviors work as expected.And it is exactly the functional safety verification needed.Therefore,to deal with the functional safety verification of the T2T link,an untimed colored petri net model is first constructed.Secondly,the verification process is performed.Conclusions can be drawn from the state space report and the computation tree logic queries.Lastly,the model is parameterized,and then data log files are obtained for further performance measurement.Results show that the proposed criteria are satisfied and there are no defects in the basic design requirements.The transmission delay has considered the reconnection,transmission errors and the interruption.The probability of the delay lower than 150 ms accounts for 98.106%,which meets the specification and the previous field test.展开更多
Objective:Although evidence has already demonstrated that the performance of Health Deliv- ery System(HDS) varies widely across nations,relatively little is known about the factors that give rise to these variations a...Objective:Although evidence has already demonstrated that the performance of Health Deliv- ery System(HDS) varies widely across nations,relatively little is known about the factors that give rise to these variations and the key point to improve the performance besides adjusting system structure.By setup of HDS performance measurement system on the base of association of financial,social,and environmental characteristics,we construct system dynamic model of HDS to simulate the invention policies.Methods: Performance measures were collected from HDS in 31 regions of China and combined with secondary data sources.Multivariate,linear,nonlinear regression and factor analysis models were used to estimate associ- ations between system characteristics and the performance.Results:Performance varied significantly with the size,financial resources and organizational structure of HDS.Performance measurement system of health delivery system was developed to give the rank of all Chinese regions.Conclusion:Performance measurement system of HDS is the basic of HDS modeling by system dynamic.展开更多
International joint ventures (IJVs) have increasingly their role in business world and also in research field of international business. There have been a lot of studies related to determinant factors of IJV perform...International joint ventures (IJVs) have increasingly their role in business world and also in research field of international business. There have been a lot of studies related to determinant factors of IJV performance. However, there are very few studies focusing on the measurement of I Jr performance. Especially, researchers have ignored how foreign parent firms really choose their measures in the evaluation of their IJV performance. This research investigates determinant factors of performance measures of 1JVs. Determinant factors of IJV performance measures include motives for establishment, establishment mode, location of IJVs, distribution of ownership in IJVs, cultural background of parent firms, and trust between partners, IJV life stages, parent firms' international experience, and relatedness of the IJVs to their parents. Performance measures are divided into financial measures and non-financial measures. The paper shows how different determinant factors are expected to lead foreign parent firms preferring one kind of measure over the other.展开更多
Balanced scorecard is a strategic information system and a performance measurement system. It integrates almost all the interests of stakeholders and mainly comprises four perspectives: management, operational, marke...Balanced scorecard is a strategic information system and a performance measurement system. It integrates almost all the interests of stakeholders and mainly comprises four perspectives: management, operational, marketing, and knowledge.展开更多
Knowledge has become the most important strategic resource of firms, and the competition among firms is more based on knowledge than before. To deal with this challenge, some firms are trying to develop knowledge stra...Knowledge has become the most important strategic resource of firms, and the competition among firms is more based on knowledge than before. To deal with this challenge, some firms are trying to develop knowledge strategies to direct their knowledge management activities, but current strategic performance measurement systems can't evaluate the performance of knowledge strategies appropriately. This article develops a performance measurement system for knowledge strategies based on Balanced Scorecard, and simulates the system with an improved Data Envelopment Analysis (DEA) model.展开更多
Workflow logs that record the execution of business processes offer very valuable data resource for real-time enterprise performance measurement. In this paper, a novel scheme that uses the technology of data warehous...Workflow logs that record the execution of business processes offer very valuable data resource for real-time enterprise performance measurement. In this paper, a novel scheme that uses the technology of data warehouse and OLAP to explore workflow logs and create complex analysis reports for enterprise performance measurement is proposed. Three key points of this scheme are studied: 1) the measure set; 2) the open and flexible architecture for workflow logs analysis system; 3) the data models in WFMS and data warehouse. A case study that shows the validity of the scheme is also provided.展开更多
As a novel micro-propulsion system for small satellites(from micro to nano),the ionic liquid electro spray propulsion system is a promising candidate.However,performance measurement and evaluation of the Ionic Liquid ...As a novel micro-propulsion system for small satellites(from micro to nano),the ionic liquid electro spray propulsion system is a promising candidate.However,performance measurement and evaluation of the Ionic Liquid Electrospray Thruster(ILET)is one of the most challenging issues for practical application,due to the difficulties in the development of a prototype and direct measurements of micro-thrust and small flow rate.To address this issue,a Modular Ionic Liquid Electrospray Thruster(MILET)prototype is constructed,and a diagnostic system for thrust and mass flow rate is specially developed based on an analytical balance method.With the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate as the propellant,a series of experiments is carried out on the MILET prototype under a wide operating condition through changing the applied voltage to control the thrust.Under different applied voltages,the thrust and the mass flow rate of the propellant are directly measured.The propulsive performance parameters of the thruster,such as thrust,specific impulse,thrust-to-power ratio,thruster efficiency,etc.,are comprehensively analyzed.Then,a performance comparison is made between the MILET and other representative ILETs.With a relatively low applied voltage ranging from 1550 V to 2000 V,the MILET achieves a quasi-constant specific impulse of 1263 s with the averaged thrust-to-power ratio of 65.2μN/W and thruster efficiency of 40.7%.The performance of ILET is also compared with other typical electric propulsions.The results demonstrate that the ILET exhibits an excellent ability of minimalization with high specific impulse and thruster efficiency,which guarantees a great superiority in micro propulsions.Finally,the ways to further improve the performance of ILET are discussed,which further confirms the potential prospect of ILET.The present result helps to advance the development and application of ILET.展开更多
As a novel paradigm,semantic communication provides an effective solution for breaking through the future development dilemma of classical communication systems.However,it remains an unsolved problem of how to measure...As a novel paradigm,semantic communication provides an effective solution for breaking through the future development dilemma of classical communication systems.However,it remains an unsolved problem of how to measure the information transmission capability for a given semantic communication method and subsequently compare it with the classical communication method.In this paper,we first present a review of the semantic communication system,including its system model and the two typical coding and transmission methods for its implementations.To address the unsolved issue of the information transmission capability measure for semantic communication methods,we propose a new universal performance measure called Information Conductivity.We provide the definition and the physical significance to state its effectiveness in representing the information transmission capabilities of the semantic communication systems and present elaborations including its measure methods,degrees of freedom,and progressive analysis.Experimental results in image transmission scenarios validate its practical applicability.展开更多
In classic agency models, first best efficiency can′t be achieved due to the trade-off between risk and incentives except that agency is risk neutral. Whereas if the principal′s objective is not contractible, an alt...In classic agency models, first best efficiency can′t be achieved due to the trade-off between risk and incentives except that agency is risk neutral. Whereas if the principal′s objective is not contractible, an alternative objective performance measurement which is contractible is always proposed. However, if the reaction of this objective performance measurement to agency′s effort differs from that of the principal′s objective, the agent would game performance measures, which leads to loss of efficiency, even if agency is risk neutral. By adding subjective weights on objective measures, or combination of subjective performance measurement with objective performance measurement, efficiency can be regained. Implications for faculty pay are also discussed.展开更多
In this article, a method for measuring the performance of adaptive optics (AO) systems is designed and validated by experiments. The Strehl ratio (SR) which is based on the target images is used to evaluate the p...In this article, a method for measuring the performance of adaptive optics (AO) systems is designed and validated by experiments. The Strehl ratio (SR) which is based on the target images is used to evaluate the performance quantitatively because it relates to the effect of AO correction directly. In the calculation of the SR, to avoid energy scaling in the diffraction-limited point spread function, an algorithm based on the integral of the optical transfer function (OTF) is proposed. Then, a 97-element AO system is established to validate this method, and a white-light fiber source is used as a point-like target. To simulate the practical conditions which influence the performance of the AO system, targets of different brightness are simulated in terms of different signal-to-noise ratios (SNRs) of the Shack-Hartmann (SH), and atmospheric turbulence is simulated in terms of the Fried's coherence length and the Greenwood's frequency. Finally, two experiments are conducted in which the SR of different simulated conditions are measured. The results of the experiments show that for a moderate SNR of SH the experimenting AO system is capable of closed-loop wavefront correction when the Fried's coherence length is larger than 5cm and the Greenwood's frequency is lower than 60 Hz. The results also show that the performance of AO is susceptible to the SNR of SH. The experiments validates the effectiveness of this method.展开更多
There are many different production situations that can be employed to meet demand. In the engineer-to- order (ETO) production situation, products are manufac- tured to meet specific customer needs by unique enginee...There are many different production situations that can be employed to meet demand. In the engineer-to- order (ETO) production situation, products are manufac- tured to meet specific customer needs by unique engineering or significant customization. In such an environment, failing to supply the required materials in the right quantities and at the right time increases the risk of breaching due date agreements and thereby losing customer satisfaction. As such, materials management is one of the most important and critical processes within production planning and control in ETO. To bring attention and improvement to this area, ETO companies may benefit from a performance measurement system (PMS) that systematically monitors how well mate- rials management is carried out. The design of a company's PMS varies with its production situation. Within the large body of literature on performance management and mea- surement, limited literature specifically addressing perfor- mance measurement in ETO has been identified. After being approached by a Norwegian ETO company requesting a PMS for materials management, the authors therefore set out to design the PMS from scratch, using literature on ETO, materials management and performance management and measurement as a starting point. The paper presents the proposed PMS. It provides a basis for further studies on the topic, and could be used by managers in ETO companies to assess and improve their materials management practice.展开更多
WiFi has become one of the most popular ways to access the Internet.However,in large-scale campus wireless networks,it is challenging for network administrators to provide optimized access quality without knowledge on...WiFi has become one of the most popular ways to access the Internet.However,in large-scale campus wireless networks,it is challenging for network administrators to provide optimized access quality without knowledge on fine-grained traffic characteristics and real network performance.In this paper,we implement PerfMon,a network performance measurement and diagnosis system,which integrates collected multi-source datasets and analysis methods.Based on PerfMon,we first conduct a comprehensive measurement on application-level traffic patterns and behaviors from multiple dimensions in the wireless network of T university(TWLAN),which is one of the largest campus wireless networks.Then we systematically study the application-level network performance.We observe that the application-level traffic behaviors and performance vary greatly across different locations and device types.The performance is far from satisfactory in some cases.To diagnose these problems,we distinguish locations and device types,and further locate the most crucial factors that affect the performance.The results of case studies show that the influential factors can effectively characterize performance changes and explain for performance degradation.展开更多
Performance measurement(PM)generates useful data for process control,facilitates communication between different sectors,and helps to align efforts on the most important aspects of the business.Thus,PM plays a key rol...Performance measurement(PM)generates useful data for process control,facilitates communication between different sectors,and helps to align efforts on the most important aspects of the business.Thus,PM plays a key role in the management of projects and organizations.PM is also important in the implementation of lean production principles and methods,such as reducing the share of nonvalue-adding activities,increasing process transparency,building continuous improvement into the process,and benchmarking.Moreover,the adoption of the lean production philosophy requires changes in PM.Despite its importance,limited studies have been conducted on the use of PM systems for assessing the impact of lean production programs in construction projects.In addition,studies on how lean companies(or projects)use performance measurement and to what extent the indicators adopted reflect the result of actions that have been undertaken are limited.This study proposes a set of requirements in PM systems of construction projects from the perspective of lean production and a taxonomy of performance metrics for lean production systems.Five empirical studies have been carried out on construction companies from South America involved in the implementation of lean production systems.The scope of this investigation is limited to the construction projects as production systems rather than PM at the level of construction organizations.展开更多
This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requi...This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requiring more training or resources for incident management. Previous NCHRP reports discussed usage of different factors including incident severity, roadway characteristics, number of lanes involved and time of incident separately for estimating the performance. However, it does not tell us how to incorporate all the factors at the same time. Thus, this study aims to account for multiple factors to ensure fair comparisons. This study used 149,174 crashes from Iowa that occurred from 2018 to 2021. A Tobit regression model was used to find the effect of different variables on roadway clearance time. Variables that cannot be controlled directly by agencies such as crash severity, roadway type, weather conditions, lighting conditions, etc., were included in the analysis as it helps to reduce bias in the ranking procedure. Then clearance time of each crash is normalized into a base condition using the regression coefficients. The normalization makes the process more efficient as the effect of uncontrollable factors has already been mitigated. Finally, the agencies were ranked by their average normalized roadway clearance time. This ranking process allows agencies to track their performance of previous crashes, can be used in identifying low performing agencies that could use additional resources and training, and can be used to identify high performing agencies to recognize for their efforts and performance.展开更多
The main objective of this paper is to propose a conceptual model about the influence of lean, agile, resilient, and green (LARG) practices on supply chain operational, economic and environmental performance. This m...The main objective of this paper is to propose a conceptual model about the influence of lean, agile, resilient, and green (LARG) practices on supply chain operational, economic and environmental performance. This model is based on the literature review about the four supply chain management paradigms and also performance measurement systems. This paper contributes to the literature by introducing a new model to improve the leanness, agility, resilience, and greenness of manufacturing supply chains. Among the suggested LARG practices, the ones influencing more the supply chain performance are the just in time and also the supplier relationships. Also the supply chain performance measures with more LARG practices influencing them are the inventory levels and the time, that is, the supply chain's operational performance is the most affected by the simultaneous paradigms deployment in the supply chain.展开更多
Due to the rapid development of mobile Internet services, such as Skype and WeChat, traditional telecom services have suffered a large decline in the business volumes in recent years. Thus, telecom operators pay much ...Due to the rapid development of mobile Internet services, such as Skype and WeChat, traditional telecom services have suffered a large decline in the business volumes in recent years. Thus, telecom operators pay much attention to analyzing the changes of the enterprise performance, in order to adjust market strategies in time. In this paper, we propose a new methodology to analyze the operation data of telecom operators dynamically,which can characterize the changing process of the operating states and predict the developing trends. In particular, the proposed methodology contains two steps: migration pattern analysis and trajectory pattern analysis.Firstly, migration analysis is based on the changing of operating states between two points-in-time, which is referred to as the migration paths. Applying the clustering analysis to the migration paths can obtain the migration patterns, which characterize the changing feature of telecom operators during a short period, e.g. one month. Secondly, we combine a sequence of consecutive migration paths to obtain the migration trajectory. Through analyzing different trajectories based on the hierarchical cluster method and the Markov chain model, we obtain the trajectory patterns,which describe the changing progress during a relatively long period, e.g. one year. Based on the trajectory patterns, we can predict the possible performance changes. Finally, we apply the proposed method to a Chinese telecom operator for an empirical research, and has obtained a lot of development rules which provides insights into current telecom.展开更多
文摘State departments of transportation’s (DOTs) decisions to invest resources to expand or implement intelligent transportation systems (ITS) programs or even retire existing infrastructure need to be based on performance evaluations. Nonetheless, an apparent gap exists between the need for ITS performance measurements and the actual implementation. The evidence available points to challenges in the ITS performance measurement processes. This paper evaluated the state of practice of performance measurement for ITS across the US and provided insights. A comprehensive literature review assessed the use of performance measures by DOTs for monitoring implemented ITS programs. Based on the gaps identified through the literature review, a nationwide qualitative survey was used to gather insights from key stakeholders on the subject matter and presented in this paper. From the data gathered, performance measurement of ITS is fairly integrated into ITS programs by DOTs, with most agencies considering the process beneficial. There, however, exist reasons that prevent agencies from measuring ITS performance to greater detail and quality. These include lack of data, fragmented or incomparable data formats, the complexity of the endeavor, lack of data scientists, and difficulty assigning responsibilities when inter-agency collaboration is required. Additionally, DOTs do not benchmark or compare their ITS performance with others for reasons that include lack of data, lack of guidance or best practices, and incomparable data formats. This paper is relevant as it provides insights expected to guide DOTs and other agencies in developing or reevaluating their ITS performance measurement processes.
文摘Emerging connected vehicle (CV) data sets have recently become commercially available, enabling analysts to develop a variety of powerful performance measures without deploying any field infrastructure. This paper presents several tools using CV data to evaluate traffic progression quality along a signalized corridor. These include both performance measures for high-level analysis as well as visualizations to examine details of the coordinated operation. With the use of CV data, it is possible to assess not only the movement of traffic on the corridor but also to consider its origin-destination (O-D) path through the corridor. Results for the real-world operation of an eight-intersection signalized arterial are presented. A series of high-level performance measures are used to evaluate overall performance by time of day, with differing results by metric. Next, the details of the operation are examined with the use of two visualization tools: a cyclic time-space diagram (TSD) and an empirical platoon progression diagram (PPD). Comparing flow visualizations developed with different included O-D paths reveals several features, such as the presence of secondary and tertiary platoons on certain sections that cannot be seen when only end-to-end journeys are included. In addition, speed heat maps are generated, providing both speed performance along the corridor and locations and the extent of the queue. The proposed visualization tools portray the corridor’s performance holistically instead of combining individual signal performance metrics. The techniques exhibited in this study are compelling for identifying locations where engineering solutions such as access management or timing plan change are required. The recent progress in infrastructure-free sensing technology has significantly increased the scope of CV data-based traffic management systems, enhancing the significance of this study. The study demonstrates the utility of CV trajectory data for obtaining high-level details of the corridor performance as well as drilling down into the minute specifics.
文摘Large diameter fans with low solidity are widely used in automotive application for engine cooling. Their designs with small chord length help reducing the torque on the electrical motor and providing a good aerodynamic compromise between several operating conditions, some of these being at high flow rate. Their global performances are measured according to the ISO standard DP 5801, which allows comparison of results from different facilities. However, some variations in global performances are observed when considering results from two different test rigs. On a fan selected for the purpose of this study, up to 6 % of efficiency is lost on the worst case. As efficiency is more than ever a key factor to select a component, some experimental and numerical investigations were conducted to analyze the fan behavior on each facility. Two sets of measurement and simulation are performed and compared. Geometries considered for the domain of computation include the test rig plenum, the torquemeter, the ground and a large domain for the atmospheric conditions. The exact fan geometry with tip clearance and under-hub ribs is also considered. Numerical results show a good agreement with experiment in both cases when convergence is reached and for low flow rate when computations are switched to unsteady mode. Comparisons show that simulations are able to capture the different fan behaviors depending on the confguration and those efficiency losses previously observed are correctly predicted. These results are further analyzed to perform some post-processing. Blade loading remains identical for both cases but disparities appear in the wake and its interaction with the surrounding. Tiny details that are often neglected during experiment and/or simulation appear to be the cause of slight variations. Position of the torquemeter and shape of the plenum are among the parameters that various and that have cumulative effects. Efficiency being a ration of pressure and torque, variations are rather important. Finally, these results are discussed in terms of rules for conception and a new geometry less sensible to loss of efficiency is proposed.
基金Funded by Chongqing Natural Science Foundation (No. CSTC2005BB2189) and Chongqing High Tech Projects Foundation (No. 8277)
文摘Fuzzy cognitive maps (FCM) is a well-established artificial intelligence technique, which can be effectively applied in the domains of performance measurement, decision making and other management science. FCM can be a useful tool in a group decision-making environment by using scientifically integrated expert knowledge. The theories of FCM and balance scorecard (BSC) both emphasize cause-and-effect relationships among indicators in a complex system, but few reports have been published addressing the combined application of these two techniques. In this paper we propose a FCM simulation model for the sample performance measurement system of Intemet-based supply chain, which is constructed by BSC theory. We gave examples to explain how FCM can be adapted to execute the causal mechanism of BSC, and also how FCM can support group decision-making and forecasting in performance measurement.
基金National Natural Science Foundation of China(No.61963023)。
文摘The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2T link would reduce the headway and improve operational efficiency.Formal methods are system design techniques that use rigorously specified mathematical models to ensure all behaviors work as expected.And it is exactly the functional safety verification needed.Therefore,to deal with the functional safety verification of the T2T link,an untimed colored petri net model is first constructed.Secondly,the verification process is performed.Conclusions can be drawn from the state space report and the computation tree logic queries.Lastly,the model is parameterized,and then data log files are obtained for further performance measurement.Results show that the proposed criteria are satisfied and there are no defects in the basic design requirements.The transmission delay has considered the reconnection,transmission errors and the interruption.The probability of the delay lower than 150 ms accounts for 98.106%,which meets the specification and the previous field test.
文摘Objective:Although evidence has already demonstrated that the performance of Health Deliv- ery System(HDS) varies widely across nations,relatively little is known about the factors that give rise to these variations and the key point to improve the performance besides adjusting system structure.By setup of HDS performance measurement system on the base of association of financial,social,and environmental characteristics,we construct system dynamic model of HDS to simulate the invention policies.Methods: Performance measures were collected from HDS in 31 regions of China and combined with secondary data sources.Multivariate,linear,nonlinear regression and factor analysis models were used to estimate associ- ations between system characteristics and the performance.Results:Performance varied significantly with the size,financial resources and organizational structure of HDS.Performance measurement system of health delivery system was developed to give the rank of all Chinese regions.Conclusion:Performance measurement system of HDS is the basic of HDS modeling by system dynamic.
文摘International joint ventures (IJVs) have increasingly their role in business world and also in research field of international business. There have been a lot of studies related to determinant factors of IJV performance. However, there are very few studies focusing on the measurement of I Jr performance. Especially, researchers have ignored how foreign parent firms really choose their measures in the evaluation of their IJV performance. This research investigates determinant factors of performance measures of 1JVs. Determinant factors of IJV performance measures include motives for establishment, establishment mode, location of IJVs, distribution of ownership in IJVs, cultural background of parent firms, and trust between partners, IJV life stages, parent firms' international experience, and relatedness of the IJVs to their parents. Performance measures are divided into financial measures and non-financial measures. The paper shows how different determinant factors are expected to lead foreign parent firms preferring one kind of measure over the other.
基金This paper is supported by National Social Science Foundation of China (No.96AJB043) and the Fund for Young Faculty of Tianjin University (No.5110104).
文摘Balanced scorecard is a strategic information system and a performance measurement system. It integrates almost all the interests of stakeholders and mainly comprises four perspectives: management, operational, marketing, and knowledge.
文摘Knowledge has become the most important strategic resource of firms, and the competition among firms is more based on knowledge than before. To deal with this challenge, some firms are trying to develop knowledge strategies to direct their knowledge management activities, but current strategic performance measurement systems can't evaluate the performance of knowledge strategies appropriately. This article develops a performance measurement system for knowledge strategies based on Balanced Scorecard, and simulates the system with an improved Data Envelopment Analysis (DEA) model.
文摘Workflow logs that record the execution of business processes offer very valuable data resource for real-time enterprise performance measurement. In this paper, a novel scheme that uses the technology of data warehouse and OLAP to explore workflow logs and create complex analysis reports for enterprise performance measurement is proposed. Three key points of this scheme are studied: 1) the measure set; 2) the open and flexible architecture for workflow logs analysis system; 3) the data models in WFMS and data warehouse. A case study that shows the validity of the scheme is also provided.
基金co-supported by NSAF,China(No.U1730134)the National Natural Science Foundation of China(No.11772310)+1 种基金the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(No.CX202034)the Innovation and Entrepreneurship Fund of the Student Affairs Department of Northwestern Polytechnical University,China(No.2021-CXCY-005)。
文摘As a novel micro-propulsion system for small satellites(from micro to nano),the ionic liquid electro spray propulsion system is a promising candidate.However,performance measurement and evaluation of the Ionic Liquid Electrospray Thruster(ILET)is one of the most challenging issues for practical application,due to the difficulties in the development of a prototype and direct measurements of micro-thrust and small flow rate.To address this issue,a Modular Ionic Liquid Electrospray Thruster(MILET)prototype is constructed,and a diagnostic system for thrust and mass flow rate is specially developed based on an analytical balance method.With the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate as the propellant,a series of experiments is carried out on the MILET prototype under a wide operating condition through changing the applied voltage to control the thrust.Under different applied voltages,the thrust and the mass flow rate of the propellant are directly measured.The propulsive performance parameters of the thruster,such as thrust,specific impulse,thrust-to-power ratio,thruster efficiency,etc.,are comprehensively analyzed.Then,a performance comparison is made between the MILET and other representative ILETs.With a relatively low applied voltage ranging from 1550 V to 2000 V,the MILET achieves a quasi-constant specific impulse of 1263 s with the averaged thrust-to-power ratio of 65.2μN/W and thruster efficiency of 40.7%.The performance of ILET is also compared with other typical electric propulsions.The results demonstrate that the ILET exhibits an excellent ability of minimalization with high specific impulse and thruster efficiency,which guarantees a great superiority in micro propulsions.Finally,the ways to further improve the performance of ILET are discussed,which further confirms the potential prospect of ILET.The present result helps to advance the development and application of ILET.
基金supported by the National Natural Science Foundation of China(No.62293481,No.62071058)。
文摘As a novel paradigm,semantic communication provides an effective solution for breaking through the future development dilemma of classical communication systems.However,it remains an unsolved problem of how to measure the information transmission capability for a given semantic communication method and subsequently compare it with the classical communication method.In this paper,we first present a review of the semantic communication system,including its system model and the two typical coding and transmission methods for its implementations.To address the unsolved issue of the information transmission capability measure for semantic communication methods,we propose a new universal performance measure called Information Conductivity.We provide the definition and the physical significance to state its effectiveness in representing the information transmission capabilities of the semantic communication systems and present elaborations including its measure methods,degrees of freedom,and progressive analysis.Experimental results in image transmission scenarios validate its practical applicability.
基金This projectis supported by the tenth five-year plan of the research on humanities & social scienceof Ministry of Education( # 0 1 JC6 30 0 0 3)
文摘In classic agency models, first best efficiency can′t be achieved due to the trade-off between risk and incentives except that agency is risk neutral. Whereas if the principal′s objective is not contractible, an alternative objective performance measurement which is contractible is always proposed. However, if the reaction of this objective performance measurement to agency′s effort differs from that of the principal′s objective, the agent would game performance measures, which leads to loss of efficiency, even if agency is risk neutral. By adding subjective weights on objective measures, or combination of subjective performance measurement with objective performance measurement, efficiency can be regained. Implications for faculty pay are also discussed.
基金supported by the National High Technology Research and Development Program of China (2014AAXXX1003X)
文摘In this article, a method for measuring the performance of adaptive optics (AO) systems is designed and validated by experiments. The Strehl ratio (SR) which is based on the target images is used to evaluate the performance quantitatively because it relates to the effect of AO correction directly. In the calculation of the SR, to avoid energy scaling in the diffraction-limited point spread function, an algorithm based on the integral of the optical transfer function (OTF) is proposed. Then, a 97-element AO system is established to validate this method, and a white-light fiber source is used as a point-like target. To simulate the practical conditions which influence the performance of the AO system, targets of different brightness are simulated in terms of different signal-to-noise ratios (SNRs) of the Shack-Hartmann (SH), and atmospheric turbulence is simulated in terms of the Fried's coherence length and the Greenwood's frequency. Finally, two experiments are conducted in which the SR of different simulated conditions are measured. The results of the experiments show that for a moderate SNR of SH the experimenting AO system is capable of closed-loop wavefront correction when the Fried's coherence length is larger than 5cm and the Greenwood's frequency is lower than 60 Hz. The results also show that the performance of AO is susceptible to the SNR of SH. The experiments validates the effectiveness of this method.
基金projects MARGIN(Integrated and Responsive Maritime Supply Chain)funded by the Regional Research Fund Mid-Norway,EFFEKT(Effective Production of Advanced Maritime Equipment)the SFI Norman(Norwegian Manufacturing Future)programme supported by the Research Council of Norway and the project Linked Design(Linked Knowledge in Manufacturing,Engineering and Design)with funding from the European Union's Seventh Framework Programme([FP7/2007-2013])(Grant No.284613)
文摘There are many different production situations that can be employed to meet demand. In the engineer-to- order (ETO) production situation, products are manufac- tured to meet specific customer needs by unique engineering or significant customization. In such an environment, failing to supply the required materials in the right quantities and at the right time increases the risk of breaching due date agreements and thereby losing customer satisfaction. As such, materials management is one of the most important and critical processes within production planning and control in ETO. To bring attention and improvement to this area, ETO companies may benefit from a performance measurement system (PMS) that systematically monitors how well mate- rials management is carried out. The design of a company's PMS varies with its production situation. Within the large body of literature on performance management and mea- surement, limited literature specifically addressing perfor- mance measurement in ETO has been identified. After being approached by a Norwegian ETO company requesting a PMS for materials management, the authors therefore set out to design the PMS from scratch, using literature on ETO, materials management and performance management and measurement as a starting point. The paper presents the proposed PMS. It provides a basis for further studies on the topic, and could be used by managers in ETO companies to assess and improve their materials management practice.
基金supported by the National Key Research and Development Program of China(No.2020YFE0200500)。
文摘WiFi has become one of the most popular ways to access the Internet.However,in large-scale campus wireless networks,it is challenging for network administrators to provide optimized access quality without knowledge on fine-grained traffic characteristics and real network performance.In this paper,we implement PerfMon,a network performance measurement and diagnosis system,which integrates collected multi-source datasets and analysis methods.Based on PerfMon,we first conduct a comprehensive measurement on application-level traffic patterns and behaviors from multiple dimensions in the wireless network of T university(TWLAN),which is one of the largest campus wireless networks.Then we systematically study the application-level network performance.We observe that the application-level traffic behaviors and performance vary greatly across different locations and device types.The performance is far from satisfactory in some cases.To diagnose these problems,we distinguish locations and device types,and further locate the most crucial factors that affect the performance.The results of case studies show that the influential factors can effectively characterize performance changes and explain for performance degradation.
文摘Performance measurement(PM)generates useful data for process control,facilitates communication between different sectors,and helps to align efforts on the most important aspects of the business.Thus,PM plays a key role in the management of projects and organizations.PM is also important in the implementation of lean production principles and methods,such as reducing the share of nonvalue-adding activities,increasing process transparency,building continuous improvement into the process,and benchmarking.Moreover,the adoption of the lean production philosophy requires changes in PM.Despite its importance,limited studies have been conducted on the use of PM systems for assessing the impact of lean production programs in construction projects.In addition,studies on how lean companies(or projects)use performance measurement and to what extent the indicators adopted reflect the result of actions that have been undertaken are limited.This study proposes a set of requirements in PM systems of construction projects from the perspective of lean production and a taxonomy of performance metrics for lean production systems.Five empirical studies have been carried out on construction companies from South America involved in the implementation of lean production systems.The scope of this investigation is limited to the construction projects as production systems rather than PM at the level of construction organizations.
文摘This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requiring more training or resources for incident management. Previous NCHRP reports discussed usage of different factors including incident severity, roadway characteristics, number of lanes involved and time of incident separately for estimating the performance. However, it does not tell us how to incorporate all the factors at the same time. Thus, this study aims to account for multiple factors to ensure fair comparisons. This study used 149,174 crashes from Iowa that occurred from 2018 to 2021. A Tobit regression model was used to find the effect of different variables on roadway clearance time. Variables that cannot be controlled directly by agencies such as crash severity, roadway type, weather conditions, lighting conditions, etc., were included in the analysis as it helps to reduce bias in the ranking procedure. Then clearance time of each crash is normalized into a base condition using the regression coefficients. The normalization makes the process more efficient as the effect of uncontrollable factors has already been mitigated. Finally, the agencies were ranked by their average normalized roadway clearance time. This ranking process allows agencies to track their performance of previous crashes, can be used in identifying low performing agencies that could use additional resources and training, and can be used to identify high performing agencies to recognize for their efforts and performance.
文摘The main objective of this paper is to propose a conceptual model about the influence of lean, agile, resilient, and green (LARG) practices on supply chain operational, economic and environmental performance. This model is based on the literature review about the four supply chain management paradigms and also performance measurement systems. This paper contributes to the literature by introducing a new model to improve the leanness, agility, resilience, and greenness of manufacturing supply chains. Among the suggested LARG practices, the ones influencing more the supply chain performance are the just in time and also the supplier relationships. Also the supply chain performance measures with more LARG practices influencing them are the inventory levels and the time, that is, the supply chain's operational performance is the most affected by the simultaneous paradigms deployment in the supply chain.
基金partially supported by NSFC (71371034 and 71372194)Beijing Natural Science Foundation (9162011)
文摘Due to the rapid development of mobile Internet services, such as Skype and WeChat, traditional telecom services have suffered a large decline in the business volumes in recent years. Thus, telecom operators pay much attention to analyzing the changes of the enterprise performance, in order to adjust market strategies in time. In this paper, we propose a new methodology to analyze the operation data of telecom operators dynamically,which can characterize the changing process of the operating states and predict the developing trends. In particular, the proposed methodology contains two steps: migration pattern analysis and trajectory pattern analysis.Firstly, migration analysis is based on the changing of operating states between two points-in-time, which is referred to as the migration paths. Applying the clustering analysis to the migration paths can obtain the migration patterns, which characterize the changing feature of telecom operators during a short period, e.g. one month. Secondly, we combine a sequence of consecutive migration paths to obtain the migration trajectory. Through analyzing different trajectories based on the hierarchical cluster method and the Markov chain model, we obtain the trajectory patterns,which describe the changing progress during a relatively long period, e.g. one year. Based on the trajectory patterns, we can predict the possible performance changes. Finally, we apply the proposed method to a Chinese telecom operator for an empirical research, and has obtained a lot of development rules which provides insights into current telecom.