The methodology of visual simulation for a tunnel engineering construction schedule is presented. Visualization of simulation model, calculation and result of construction schedule simulation is realized, and the cons...The methodology of visual simulation for a tunnel engineering construction schedule is presented. Visualization of simulation model, calculation and result of construction schedule simulation is realized, and the construction simulation and the resource optimization of tunnel engineering are made. A risk analysis and a decision-making method of tunnel engineering construction schedule based on visual simulation are presented. Furthermore, using S curve theory and schedule management method, the real-time management and control method of tunnel engineering construction based on visual simulation is presented. The application to the tunnel engineering construction schedule analysis and management shows the feasibility and effectiveness of the method presented in this paper.展开更多
The practical problems all students may face at some point in their college life are procrastination and time management. A recent survey shows that most of the first-year college students with language learning disab...The practical problems all students may face at some point in their college life are procrastination and time management. A recent survey shows that most of the first-year college students with language learning disabilities lack time-management skills. In order to help the students solve these problems, a language teacher should not only help students to develop their language skills, but also help them to learn some techniques of time-management. To ensure that, teachers need to help the students with the setting of clear goals and ways of planning and scheduling time for a balanced lifestyle.展开更多
Objective:To explore the time management tendency of left-behind adolescents,compare the differences of time management of left-behind.Methods:The questionnaire studies the adolescents students of major labor.Results:...Objective:To explore the time management tendency of left-behind adolescents,compare the differences of time management of left-behind.Methods:The questionnaire studies the adolescents students of major labor.Results:Left-behind adolescents are tend to form bad time management tendency(t<2.55,p<0.01)and among these left-behind adolescents there are great individual differences(F>4.24,p>0.05);16-year-old time is a critical period of forming social value of time management(F>4.24,p>0.05),the grade(F_((2,331))=3.74,p=0.03),and whether the only child(t=2.26,p=0.03)has priority to the impact of time management;the children’s age when their parents left.The left period of their parents,the parents who go out,and the visit interval all these factors affect the adolescents’time management tendency(R^(2)>0.21,p<0.001).展开更多
Objective: To evaluate the correlation between time management disposition and ability confidence of Nursing Students in China through the Pearson correlation coefficient. Methods: Electronic databases including the...Objective: To evaluate the correlation between time management disposition and ability confidence of Nursing Students in China through the Pearson correlation coefficient. Methods: Electronic databases including the Cochrane library, PubMed, EMBASE, the Web of Science, CBM, Wanfang, VIP and CNKI were searched from inception to October 2017 to collect literature on the correlation between time manage-ment disposition and ability confidence of Chinese nursing students. The studies were examined according to the inclusion and exclusion criteria. After extracting data and evaluating the quality of the included studies. Meta-analysis was carried out using Stata 12.0 software. Results: A total of 7 articles with 1632 nursing students were included, and the quality of the literature was at medium level. Meta-analysis shown the total score of time management disposition of Chinese nursing students and its three dimensions were related to ability confidence. The summary correlation coefficient between time management disposition and ability confidence was 0.52 (0.43 to 0.59) ; There is a weak correlation between time value and ability confidence (r, 0.33; 95% CI, 0.25 to 0.39); There was a moderate level of correlation between time control and ability confidence (r, 0.49; 95% CI, 0.43 to 0.54); There was a moderate level of correlation between time efficacy and ability confidence (0.47, 0.41, 0.53).And the relevance of nursing time management disposition and behavioral confidence varies with the nursing student's area, nursing student's diploma, measurement tools and sample size. Conclusion: The time man- agement disposition of Chinese nursing students is moderately related to ability confidence. When there are different in nursing students in the area, nursing diploma, measurement tools and sample size, the relevance is very different. The time management disposition of Chinese nursing students and their ability confidence are mutually reinforcing, and the time management disposition and their ability confidence should be further strengthened in the future.展开更多
Teaching is a complicated system, involving the knowledge, ability, skills, quahty and other aspects, eacla ot wmcn presents a multidimensional structure. During the limited teaching time, it can't guarantee to finis...Teaching is a complicated system, involving the knowledge, ability, skills, quahty and other aspects, eacla ot wmcn presents a multidimensional structure. During the limited teaching time, it can't guarantee to finish and cover so many teaching contents and tasks without careful time management. Even if there is enough time, it can't result in high teaching efficiency naturally. The phenomenon of time-consuming but inefficiency often appears. How to optimize time management to improve teaching efficiency is worthy of our constant research. Take college English class as an example, this paper attempts to construct a general and high-efficiency time management mode of college English class based on some second language acquisition theories, combined with some teaching practice, improve the effect of the current college English teaching, and as a reference for other subjects.展开更多
Forecasting is predicting or estimating a future event or trend.Supply chains have been constantly growing in most countries ever since the industrial revolution of the 18th century.As the competitiveness between supp...Forecasting is predicting or estimating a future event or trend.Supply chains have been constantly growing in most countries ever since the industrial revolution of the 18th century.As the competitiveness between supply chains intensifies day by day,companies are shifting their focus to predictive analytics techniques to minimize costs and boost productivity and profits.Excessive inventory(overstock)and stock outs are very significant issues for suppliers.Excessive inventory levels can lead to loss of revenue because the company's capital is tied up in excess inventory.Excess inventory can also lead to increased storage,insurance costs and labor as well as lower and degraded quality based on the nature of the product.Shortages or out of stock can lead to lost sales and a decline in customer contentment and loyalty to the store.If clients are unable to find the right products on the shelves,they may switch to another vendor or purchase alternative items.Demand forecasting is valuable for planning,scheduling and improving the coordination of all supply chain activities.This paper discusses the use of neural networks for seasonal time series forecasting.Our objective is to evaluate the contribution of the correct choice of the transfer function by proposing a new form of the transfer function to improve the quality of the forecast.展开更多
One of the key factors in a profitable open-pit mine is the efficiency of the waste disposal system. Using GPS-technology, the truck-dispatching decisions can be made in real-time but the chosen strategy has a crucial...One of the key factors in a profitable open-pit mine is the efficiency of the waste disposal system. Using GPS-technology, the truck-dispatching decisions can be made in real-time but the chosen strategy has a crucial role. Therefore, finding the optimal dispatching strategy for truck-shovel operations is extremely important. Dispatching strategies have been reported in the literature, but the comparison of these strategies is still missing. This paper illustrates the differences between the strategies by conducting a stochastic simulation study based on the data gathered from an actual mine. The findings underline the importance of the global vision in dispatching decisions.展开更多
With the rapid development of network, the phenomenon of Internet addiction is prevalent on campuses, which has produced a variety of negative effects on college students in terms of learning, living, working and so o...With the rapid development of network, the phenomenon of Internet addiction is prevalent on campuses, which has produced a variety of negative effects on college students in terms of learning, living, working and so on. In recent years, there are many research literatures on Internet addiction overseas, covering all aspects of this psychological phenomenon. Moreover, domestic research on Internet addiction started late. In the light of the fact that college students do not have clear understanding on hazards of Interact addiction, it generally shows their self- control is poor. They do not believe they can control their behavior and results and give up taking responsibility for the results and tend to agree network identity. Based on this phenomenon, we propose the network psychological source control concept. In view of the close contact between the excessive use of the network and the individual time management, this study selected the time dimension of personality characteristics on Internet addiction as another influencing factor, and explored the integrated influence of the psychological source control to Internet addiction.展开更多
Demand forecasting and big data analytics in supply chain management are gaining interest.This is attributed to the wide range of big data analytics in supply chain management,in addition to demand forecasting,and beh...Demand forecasting and big data analytics in supply chain management are gaining interest.This is attributed to the wide range of big data analytics in supply chain management,in addition to demand forecasting,and behavioral analysis.In this article,we studied the application of big data analytics forecasting in supply chain demand forecasting in the automotive parts industry to propose classifications of these applications,identify gaps,and provide ideas for future research.Algorithms will then be classified and then applied in supply chain management such as neural networks,k-nearest neighbors,time series forecasting,clustering,regression analysis,support vector regression and support vector machines.An extensive hierarchical model for short-term auto parts demand assess-ment was employed to avoid the shortcomings of the earlier models and to close the gap that regarded mainly a single time series.The concept of extensive relevance assessment was proposed,and subsequently methods to reflect the relevance of automotive demand factors were discussed.Using a wide range of skills,the factors and co-factors are expressed in the form of a correlation characteristic matrix to ensure the degree of influence of each factor on the demand for automotive components.Then,it is compared with the existing data and predicted the short-term historical data.The result proved the predictive error is less than 6%,which supports the validity of the prediction method.This research offers the basis for the macroeconomic regulation of the government and the production of auto parts manufacturers.展开更多
With the objective of reducing the flight cost and the amount of polluting emissions released in the atmosphere, a new optimization algorithm considering the climb, cruise and descent phases is presented for the refer...With the objective of reducing the flight cost and the amount of polluting emissions released in the atmosphere, a new optimization algorithm considering the climb, cruise and descent phases is presented for the reference vertical flight trajectory. The selection of the reference vertical navigation speeds and altitudes was solved as a discrete combinatory problem by means of a graphtree passing through nodes using the beam search optimization technique. To achieve a compromise between the execution time and the algorithm's ability to find the global optimal solution, a heuristic methodology introducing a parameter called ‘‘optimism coefficient was used in order to estimate the trajectory's flight cost at every node. The optimal trajectory cost obtained with the developed algorithm was compared with the cost of the optimal trajectory provided by a commercial flight management system(FMS). The global optimal solution was validated against an exhaustive search algorithm(ESA), other than the proposed algorithm. The developed algorithm takes into account weather effects, step climbs during cruise and air traffic management constraints such as constant altitude segments, constant cruise Mach, and a pre-defined reference lateral navigation route. The aircraft fuel burn was computed using a numerical performance model which was created and validated using flight test experimental data.展开更多
Background:Measuring the size of the infectious pool of tuberculosis(TB)is essential to understand the burden and monitor trends of TB control program performance.This study applied the concept of TB management time t...Background:Measuring the size of the infectious pool of tuberculosis(TB)is essential to understand the burden and monitor trends of TB control program performance.This study applied the concept of TB management time to estimate and compare the size of the TB infectious pool between 2009 and 2014 in West Gojjam Zone of Amhara Region,Ethiopia.Methods:New sputum smear-positive and smear-negative pulmonary TB(PTB)and retreatment cases who attended 30 randomly selected public health facilities in West Gojjam Zone from October 2013 to October 2014 were consecutively enrolled in the study.In order to determine the infectious period,the TB management time(number of days from the onset of cough until start of anti-TB treatment)was computed for each patient category.The number of undiagnosed TB cases was estimated and hence the TB management time for the undiagnosed category was calculated.The total size of the TB infectious pool during the study period for the study zone was estimated as the annual number of infectious person days.Results:New smear-positive and smear-negative PTB cases contributed 25,050 and 12,931 infectious person days per year to the TB infectious pool,respectively.The retreatment and presently undiagnosed cases contributed 8840 and 34,310 infectious person days per year,respectively.The total size of the TB infectious pool in West Gojjam Zone during the study period was estimated at 81,131 infectious person days per year or 3405 infectious person days per 100,000 population per year.Compared to a similar study done in 2009 in the study area,the current study showed reduction of the TB infectious pool by 244,279 infectious person days.Conclusions:TB management time is a simple and practical tool that may help to estimate and compare the changes in the size of the TB infectious pool at local level.It may also be used as an indicator to monitor the changes in TB control program performance.展开更多
Getting the right people in the right place at the right time has always been a major organizational challenge. In ancient times this process seems to have been accomplished based on the scheme of arrangements being c...Getting the right people in the right place at the right time has always been a major organizational challenge. In ancient times this process seems to have been accomplished based on the scheme of arrangements being contained in the leader's mind and instructions communicated verbally. Modem approaches to solving the twin challenges of first thinking through the 'plan' and then communicating the plan to the people who need to do 'the right work, at the right time, in the right place' use sophisticated graphics, charts, diagrams, and computa- tions. This paper traces the development of the concepts most project managers take for granted including bar charts and critical path schedules from their origins (which are far earlier than most people think) through to the modem day. The first section of the paper looks at the development of concepts that allow the visualization of time and other data. The second looks at the shift from static representations to dynamic modeling through the emergence of computers, dynamic calculations and integrated data from the 1950s to the present time.展开更多
Manufacturing and services constitute two of the five sectors of every country's economy;depending on the maturity of the economy,they are-in terms of employment-typically the two largest sectors.The outputs or produ...Manufacturing and services constitute two of the five sectors of every country's economy;depending on the maturity of the economy,they are-in terms of employment-typically the two largest sectors.The outputs or products of an economy can also be divided into goods products(due to manufacturing,construction,agriculture and mining) and services products.To date,the goods and services products have,for the most part,been mass produced;it is the premise of this paper that recent technological advances-including flexible manufacturing,cloud computing,nanotechnology and smart sensing-can better enable the transformation from mass production to mass customization.We regard mass customization as the simultaneous and real time management of supply and demand chains,based on a taxonomy that can be defined in terms of its underpinning component and management foci.From a components perspective,we first consider the value chain of supplier,manufacturer,assembler,retailer,and customer,and then develop a consistent set of definitions for supply and demand chains based on the location of the customer order penetration point.From a management perspective,we classify the methods that are employed in the management of these chains,based on whether supply and/or demand are flexible or fixed.Interestingly,our management taxonomy highlights a very critical research area at which both supply and demand are flexible,thus manageable.Simultaneous management of supply and demand chains sets the stage for mass customization which is concerned with meeting the needs of an individualized customer market.Simultaneous and real time management of supply and demand chains set the stage for real time mass customization(e.g.,wherein a tailor first laser scans an individual's upper torso and then delivers a uniquely fitted jacket within a reasonable period,while the individual is waiting).The benefits of real time mass customization cannot be over-stated as goods and services become indistinguishable and are co-produced-as "servgoods"-in real time,resulting in an overwhelming economic advantage.展开更多
Traffic management aims to ensure a high quality of service for most users by decreasing congestion and increasing safety. However, uncertainty regarding travel time decreases the quality of service and leads end-user...Traffic management aims to ensure a high quality of service for most users by decreasing congestion and increasing safety. However, uncertainty regarding travel time decreases the quality of service and leads end-users to change their routes and schedules even when the average travel time is low, Indicators describing travel time reliability are being developed and should be used in the future both for the optimization and the assessment of active traffic management operation. This paper describes a managed lane experience on a motorway weaving section in France - hard shoulder running operation in rush hours. The paper is focused on travel time reliability indicators and their use for reliability assessment. It provides some discussions about the advantages and drawbacks of reliability indicators under different traffic conditions. It particularly shows the difference between using buffer times and buffer indexes. The paper also discusses the difficulty of interpreting the skew of travel time distribution for travel reliability,展开更多
基金Supported by National Natural Science Foundation of China (No.50539120)Natural Fund for Distinguished Young Scholars of China(No.50525927)
文摘The methodology of visual simulation for a tunnel engineering construction schedule is presented. Visualization of simulation model, calculation and result of construction schedule simulation is realized, and the construction simulation and the resource optimization of tunnel engineering are made. A risk analysis and a decision-making method of tunnel engineering construction schedule based on visual simulation are presented. Furthermore, using S curve theory and schedule management method, the real-time management and control method of tunnel engineering construction based on visual simulation is presented. The application to the tunnel engineering construction schedule analysis and management shows the feasibility and effectiveness of the method presented in this paper.
文摘The practical problems all students may face at some point in their college life are procrastination and time management. A recent survey shows that most of the first-year college students with language learning disabilities lack time-management skills. In order to help the students solve these problems, a language teacher should not only help students to develop their language skills, but also help them to learn some techniques of time-management. To ensure that, teachers need to help the students with the setting of clear goals and ways of planning and scheduling time for a balanced lifestyle.
文摘Objective:To explore the time management tendency of left-behind adolescents,compare the differences of time management of left-behind.Methods:The questionnaire studies the adolescents students of major labor.Results:Left-behind adolescents are tend to form bad time management tendency(t<2.55,p<0.01)and among these left-behind adolescents there are great individual differences(F>4.24,p>0.05);16-year-old time is a critical period of forming social value of time management(F>4.24,p>0.05),the grade(F_((2,331))=3.74,p=0.03),and whether the only child(t=2.26,p=0.03)has priority to the impact of time management;the children’s age when their parents left.The left period of their parents,the parents who go out,and the visit interval all these factors affect the adolescents’time management tendency(R^(2)>0.21,p<0.001).
文摘Objective: To evaluate the correlation between time management disposition and ability confidence of Nursing Students in China through the Pearson correlation coefficient. Methods: Electronic databases including the Cochrane library, PubMed, EMBASE, the Web of Science, CBM, Wanfang, VIP and CNKI were searched from inception to October 2017 to collect literature on the correlation between time manage-ment disposition and ability confidence of Chinese nursing students. The studies were examined according to the inclusion and exclusion criteria. After extracting data and evaluating the quality of the included studies. Meta-analysis was carried out using Stata 12.0 software. Results: A total of 7 articles with 1632 nursing students were included, and the quality of the literature was at medium level. Meta-analysis shown the total score of time management disposition of Chinese nursing students and its three dimensions were related to ability confidence. The summary correlation coefficient between time management disposition and ability confidence was 0.52 (0.43 to 0.59) ; There is a weak correlation between time value and ability confidence (r, 0.33; 95% CI, 0.25 to 0.39); There was a moderate level of correlation between time control and ability confidence (r, 0.49; 95% CI, 0.43 to 0.54); There was a moderate level of correlation between time efficacy and ability confidence (0.47, 0.41, 0.53).And the relevance of nursing time management disposition and behavioral confidence varies with the nursing student's area, nursing student's diploma, measurement tools and sample size. Conclusion: The time man- agement disposition of Chinese nursing students is moderately related to ability confidence. When there are different in nursing students in the area, nursing diploma, measurement tools and sample size, the relevance is very different. The time management disposition of Chinese nursing students and their ability confidence are mutually reinforcing, and the time management disposition and their ability confidence should be further strengthened in the future.
文摘Teaching is a complicated system, involving the knowledge, ability, skills, quahty and other aspects, eacla ot wmcn presents a multidimensional structure. During the limited teaching time, it can't guarantee to finish and cover so many teaching contents and tasks without careful time management. Even if there is enough time, it can't result in high teaching efficiency naturally. The phenomenon of time-consuming but inefficiency often appears. How to optimize time management to improve teaching efficiency is worthy of our constant research. Take college English class as an example, this paper attempts to construct a general and high-efficiency time management mode of college English class based on some second language acquisition theories, combined with some teaching practice, improve the effect of the current college English teaching, and as a reference for other subjects.
文摘Forecasting is predicting or estimating a future event or trend.Supply chains have been constantly growing in most countries ever since the industrial revolution of the 18th century.As the competitiveness between supply chains intensifies day by day,companies are shifting their focus to predictive analytics techniques to minimize costs and boost productivity and profits.Excessive inventory(overstock)and stock outs are very significant issues for suppliers.Excessive inventory levels can lead to loss of revenue because the company's capital is tied up in excess inventory.Excess inventory can also lead to increased storage,insurance costs and labor as well as lower and degraded quality based on the nature of the product.Shortages or out of stock can lead to lost sales and a decline in customer contentment and loyalty to the store.If clients are unable to find the right products on the shelves,they may switch to another vendor or purchase alternative items.Demand forecasting is valuable for planning,scheduling and improving the coordination of all supply chain activities.This paper discusses the use of neural networks for seasonal time series forecasting.Our objective is to evaluate the contribution of the correct choice of the transfer function by proposing a new form of the transfer function to improve the quality of the forecast.
文摘One of the key factors in a profitable open-pit mine is the efficiency of the waste disposal system. Using GPS-technology, the truck-dispatching decisions can be made in real-time but the chosen strategy has a crucial role. Therefore, finding the optimal dispatching strategy for truck-shovel operations is extremely important. Dispatching strategies have been reported in the literature, but the comparison of these strategies is still missing. This paper illustrates the differences between the strategies by conducting a stochastic simulation study based on the data gathered from an actual mine. The findings underline the importance of the global vision in dispatching decisions.
文摘With the rapid development of network, the phenomenon of Internet addiction is prevalent on campuses, which has produced a variety of negative effects on college students in terms of learning, living, working and so on. In recent years, there are many research literatures on Internet addiction overseas, covering all aspects of this psychological phenomenon. Moreover, domestic research on Internet addiction started late. In the light of the fact that college students do not have clear understanding on hazards of Interact addiction, it generally shows their self- control is poor. They do not believe they can control their behavior and results and give up taking responsibility for the results and tend to agree network identity. Based on this phenomenon, we propose the network psychological source control concept. In view of the close contact between the excessive use of the network and the individual time management, this study selected the time dimension of personality characteristics on Internet addiction as another influencing factor, and explored the integrated influence of the psychological source control to Internet addiction.
文摘Demand forecasting and big data analytics in supply chain management are gaining interest.This is attributed to the wide range of big data analytics in supply chain management,in addition to demand forecasting,and behavioral analysis.In this article,we studied the application of big data analytics forecasting in supply chain demand forecasting in the automotive parts industry to propose classifications of these applications,identify gaps,and provide ideas for future research.Algorithms will then be classified and then applied in supply chain management such as neural networks,k-nearest neighbors,time series forecasting,clustering,regression analysis,support vector regression and support vector machines.An extensive hierarchical model for short-term auto parts demand assess-ment was employed to avoid the shortcomings of the earlier models and to close the gap that regarded mainly a single time series.The concept of extensive relevance assessment was proposed,and subsequently methods to reflect the relevance of automotive demand factors were discussed.Using a wide range of skills,the factors and co-factors are expressed in the form of a correlation characteristic matrix to ensure the degree of influence of each factor on the demand for automotive components.Then,it is compared with the existing data and predicted the short-term historical data.The result proved the predictive error is less than 6%,which supports the validity of the prediction method.This research offers the basis for the macroeconomic regulation of the government and the production of auto parts manufacturers.
基金the team of the Business-led Network of Centers of Excellence Green Aviation Research & Development Network (GARDN)in particular Mr. Sylvan Cofsky, for the funds received for this project (GARDNⅡ–Project: CMC-21)conducted at The Research Laboratory in Active Controls, Avionics and Aeroservoelasticity (LARCASE) in the framework of the global project ‘‘Optimized Descent and Cruise”
文摘With the objective of reducing the flight cost and the amount of polluting emissions released in the atmosphere, a new optimization algorithm considering the climb, cruise and descent phases is presented for the reference vertical flight trajectory. The selection of the reference vertical navigation speeds and altitudes was solved as a discrete combinatory problem by means of a graphtree passing through nodes using the beam search optimization technique. To achieve a compromise between the execution time and the algorithm's ability to find the global optimal solution, a heuristic methodology introducing a parameter called ‘‘optimism coefficient was used in order to estimate the trajectory's flight cost at every node. The optimal trajectory cost obtained with the developed algorithm was compared with the cost of the optimal trajectory provided by a commercial flight management system(FMS). The global optimal solution was validated against an exhaustive search algorithm(ESA), other than the proposed algorithm. The developed algorithm takes into account weather effects, step climbs during cruise and air traffic management constraints such as constant altitude segments, constant cruise Mach, and a pre-defined reference lateral navigation route. The aircraft fuel burn was computed using a numerical performance model which was created and validated using flight test experimental data.
基金University of Oslo funded the study.The funder had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript。
文摘Background:Measuring the size of the infectious pool of tuberculosis(TB)is essential to understand the burden and monitor trends of TB control program performance.This study applied the concept of TB management time to estimate and compare the size of the TB infectious pool between 2009 and 2014 in West Gojjam Zone of Amhara Region,Ethiopia.Methods:New sputum smear-positive and smear-negative pulmonary TB(PTB)and retreatment cases who attended 30 randomly selected public health facilities in West Gojjam Zone from October 2013 to October 2014 were consecutively enrolled in the study.In order to determine the infectious period,the TB management time(number of days from the onset of cough until start of anti-TB treatment)was computed for each patient category.The number of undiagnosed TB cases was estimated and hence the TB management time for the undiagnosed category was calculated.The total size of the TB infectious pool during the study period for the study zone was estimated as the annual number of infectious person days.Results:New smear-positive and smear-negative PTB cases contributed 25,050 and 12,931 infectious person days per year to the TB infectious pool,respectively.The retreatment and presently undiagnosed cases contributed 8840 and 34,310 infectious person days per year,respectively.The total size of the TB infectious pool in West Gojjam Zone during the study period was estimated at 81,131 infectious person days per year or 3405 infectious person days per 100,000 population per year.Compared to a similar study done in 2009 in the study area,the current study showed reduction of the TB infectious pool by 244,279 infectious person days.Conclusions:TB management time is a simple and practical tool that may help to estimate and compare the changes in the size of the TB infectious pool at local level.It may also be used as an indicator to monitor the changes in TB control program performance.
文摘Getting the right people in the right place at the right time has always been a major organizational challenge. In ancient times this process seems to have been accomplished based on the scheme of arrangements being contained in the leader's mind and instructions communicated verbally. Modem approaches to solving the twin challenges of first thinking through the 'plan' and then communicating the plan to the people who need to do 'the right work, at the right time, in the right place' use sophisticated graphics, charts, diagrams, and computa- tions. This paper traces the development of the concepts most project managers take for granted including bar charts and critical path schedules from their origins (which are far earlier than most people think) through to the modem day. The first section of the paper looks at the development of concepts that allow the visualization of time and other data. The second looks at the shift from static representations to dynamic modeling through the emergence of computers, dynamic calculations and integrated data from the 1950s to the present time.
文摘Manufacturing and services constitute two of the five sectors of every country's economy;depending on the maturity of the economy,they are-in terms of employment-typically the two largest sectors.The outputs or products of an economy can also be divided into goods products(due to manufacturing,construction,agriculture and mining) and services products.To date,the goods and services products have,for the most part,been mass produced;it is the premise of this paper that recent technological advances-including flexible manufacturing,cloud computing,nanotechnology and smart sensing-can better enable the transformation from mass production to mass customization.We regard mass customization as the simultaneous and real time management of supply and demand chains,based on a taxonomy that can be defined in terms of its underpinning component and management foci.From a components perspective,we first consider the value chain of supplier,manufacturer,assembler,retailer,and customer,and then develop a consistent set of definitions for supply and demand chains based on the location of the customer order penetration point.From a management perspective,we classify the methods that are employed in the management of these chains,based on whether supply and/or demand are flexible or fixed.Interestingly,our management taxonomy highlights a very critical research area at which both supply and demand are flexible,thus manageable.Simultaneous management of supply and demand chains sets the stage for mass customization which is concerned with meeting the needs of an individualized customer market.Simultaneous and real time management of supply and demand chains set the stage for real time mass customization(e.g.,wherein a tailor first laser scans an individual's upper torso and then delivers a uniquely fitted jacket within a reasonable period,while the individual is waiting).The benefits of real time mass customization cannot be over-stated as goods and services become indistinguishable and are co-produced-as "servgoods"-in real time,resulting in an overwhelming economic advantage.
文摘Traffic management aims to ensure a high quality of service for most users by decreasing congestion and increasing safety. However, uncertainty regarding travel time decreases the quality of service and leads end-users to change their routes and schedules even when the average travel time is low, Indicators describing travel time reliability are being developed and should be used in the future both for the optimization and the assessment of active traffic management operation. This paper describes a managed lane experience on a motorway weaving section in France - hard shoulder running operation in rush hours. The paper is focused on travel time reliability indicators and their use for reliability assessment. It provides some discussions about the advantages and drawbacks of reliability indicators under different traffic conditions. It particularly shows the difference between using buffer times and buffer indexes. The paper also discusses the difficulty of interpreting the skew of travel time distribution for travel reliability,