In this paper, a mathematical model about the optimal booking level problem in airline overbooking rnanageanent is proposed. Firstly, the normal distribution is employed to approximate Poisson requests and binomial go...In this paper, a mathematical model about the optimal booking level problem in airline overbooking rnanageanent is proposed. Firstly, the normal distribution is employed to approximate Poisson requests and binomial goshows. By calculating the mean loss, a model to describe the relationship between booking level and flight revenue is established. Then, an equation is deduced to decide the optimal booking level. Finally, a numerical example is utilized to illustrate the proposed model and discuss the impact of refund rate on the optimal booking level and the mean loss.展开更多
1930s was the golden age for the flying-boat airlines in the world, notably the Pan Am Clipper transpacific and transatlantic routes, and the （British） Imperial Airways UK-Africa and UK-Australia/Far East routes. Th...1930s was the golden age for the flying-boat airlines in the world, notably the Pan Am Clipper transpacific and transatlantic routes, and the （British） Imperial Airways UK-Africa and UK-Australia/Far East routes. The major advantage of the flying boats was its endless runway （i.e., ocean or lake） and resultant possibilities for larger aircrafts than land-based airliners. Airlines such as Pan Am made large investments in the 1930s for flying boats, their special terminals by the water, and the worldwide flying-boat air route network. However, in the late 1940s to early 1950s, the flying boats suddenly disappeared due to the rapid development of land-based large airliners and long runways, according to the previous studies. The author conducted historical research on this topic, and found another reason： rapid decline in the high-income population who used to travel by flying boat scheduled flights. Also found was a recent surge of the luxury market, and steady increase in the cruise-ship passengers. Hence, there could be implications for revival of the flying boat flights as luxury cruise, rather than as scheduled flights.展开更多
In underground constructions, a good ventilation design not only delivers fresh air to establish good working environment, but also provides a scientific and reliable basis to prevent disasters. In emergency cases, un...In underground constructions, a good ventilation design not only delivers fresh air to establish good working environment, but also provides a scientific and reliable basis to prevent disasters. In emergency cases, unexpected closure of the main airways may occur, providing the workers with alternative airways is substantial. This is important not only to sustain personnel lives, but also to prevent the mine ventilation system from damage. In this research, alternate solutions were introduced in case of failure in the underground construction to keep a pre-assigned fixed quantity in a working place for mine ventilation network. Eight different collapse scenarios were proposed to study their effect on the air quantity distribution among the branches in the ventilation circuit. From these scenarios, it is found that providing a sufficient air quantity in the working places could be achieved through modification of the network topology and adjusting the values of the regulators pressure. It is also indicated that the distance between the collapse and working places has a great effect on the amount of air delivered to it. A reduction in the power consumption could be done by re-arrange the installed regulators and decreasing the number of nodes and branches inside the network. A relationship representing the effect of changing the network topology on the total network power consumption was deduced through regression analysis. It is found that the total network power is quadratic dependent on the number of regulators and number of branches while it is directly dependent on the regulator power.展开更多
To investigate airflow pattern and its impact on particle deposition, finite-volume based computational fluid dynamics （CFD） simulations were conducted in the diseased triple-bifitrcation airways. Computations were ...To investigate airflow pattern and its impact on particle deposition, finite-volume based computational fluid dynamics （CFD） simulations were conducted in the diseased triple-bifitrcation airways. Computations were carried out for twenty Reynolds numbers ranging from 100 to 2 000 in the step of 100. Particles in the size range of 1-10 μm were conducted. Two particle deposition mechanisms （gravitational sedimentation and inertial impaction） were considered. The results indicate that there are strong relationship between airflow structures and particle deposition patterns. Deposition efficiency is different for different particles in the whole range of the respiratory rates. Particles in different sizes can deposit at different sites. Smaller particles can be uniformly deposited at the inside wall of the considered model. Larger particles can be mainly deposited in the proximal bifurcations. Deposition fraction varies a lot for different inlet Reynolds numbers. For lower Reynolds numbers, deposition fraction is relatively small and varies a little with varying the diameters. For Reynolds number to target the aerosols at the specific site. higher Reynolds numbers, there is a most efficient diameter for each展开更多
This study is to explore a suitable method to classify landform, in order to support the decision making for community siting in mountainous areas.It first proposes the landform classification for community siting(LCC...This study is to explore a suitable method to classify landform, in order to support the decision making for community siting in mountainous areas.It first proposes the landform classification for community siting(LCCS) method with detailed discussions on its rationality and the chosen parameters.This method is then tested and verified in Quxian county.The LCCS method entails twograde parameters, which uses relative relief as the first grading parameter, slope as the second, followed by a synthesis process to form a suitable landform classification system.By applying the LCCS method in Quxian county, the result shows that its use of watershed to identify geomorphometric units, and its use of the altitude datum concept, can effectively classify landform according to the local cultural traditions, and the economic and environmental conditions.The verification result shows that comparing to the conventional methods, the LCCS method respects to people's daily experience due to its bottom-up approach.It not only help to minimize the disturbance to the nature when choosing locations for community development, but also helps to prepare more precise land management policies,which maximizes agricultural production and minimizes terrain transformation.展开更多
For the last 10 years,the Venezuelan aerospace industry has been constantly growing,and it is to be expected to continue in the same way in the future.China and its space industry,as the main partner for most of the o...For the last 10 years,the Venezuelan aerospace industry has been constantly growing,and it is to be expected to continue in the same way in the future.China and its space industry,as the main partner for most of the ongoing Venezuelan space projects from their beginning,has been an important player in their development and may continue acting as one of the most important partners not only for the Venezuelan aerospace industry but also for other Latin-American countries' aerospace industries.ABAE(Bolivarian Agency for Space Activities) together with the related Chinese aerospace companies,with the guidance and help of CGWIC,has been constantly improving its cooperation methods,regarding technical work flows as well as management activities,especially for the latest's space projects under development,namely the CIDE(Venezuelan Design,Assembly,Integration and Testing Center) and VRSS-2(Venezuelan Remote Sensing Satellite-2) programs.Provided that there is a deeper and stronger cooperation in the future,partnership and friendship of the different scientists,experts and leaders from the space sectors of both countries,will be improved and strengthened for the development of both nations social welfare.展开更多
The tourist industry, as global mass phenomenon, is inextricably linked to the evolution of air transport systems and air carriers, in turn, depends on tourism to ensure stability in routes and prices. Therefore, both...The tourist industry, as global mass phenomenon, is inextricably linked to the evolution of air transport systems and air carriers, in turn, depends on tourism to ensure stability in routes and prices. Therefore, both sectors must face the new challenges together, the transport industry is heading a problem of energy and cost overruns, that inevitably will affect tourism in the short term. The first energy crisis that they are starting to live, has been mitigated by changes in three parameters： （1） the international regulation of commercial aviation; （2） the connectivity and business （birth of low cost companies） models; and （3） the new policies for climate change and gas emission. So far, the rapid growth of the tourist industry has being held on a fast and cheap access to transport energy resources based on the false belief of unlimited access to energy. The article is a review of the state of the art, and the research papers published on air transportation, relating to tourism and the emergence of low cost airlines, in order to give a global vision for the decision makers of mass destinations, as it is the case of the Canary Islands that we will use as a reference.展开更多
Tourism is becoming a vital component for economic development in South Africa. The income generated by the tourism industry is about 6% of the GDP, which is significant but still falls short of the goal set by the Wh...Tourism is becoming a vital component for economic development in South Africa. The income generated by the tourism industry is about 6% of the GDP, which is significant but still falls short of the goal set by the White Paper on Tourism in 2000. In the light of South Africa hosting the 2010 Football World Cup, it is important to identify ways of sustainable tourism development that would continue to increase the benefits to the economy long after the event＇s over. The main objective of the research was to explore an idea for increasing the level of tourist income generated in the Port Elizabeth （Eastern Cape） area. The idea was researched by means of conducting a cost-benefit analysis of two tourist related projects. These projects would introduce Charter airline services between Europe and Port Elizabeth. A second objective was to identify constraints on the project or market failures which would prevent their implementation. The economic theory behind the operation of an airline showed that lease costs and aeroplane operating costs are the two most important factors determine Charter airline＇s profitability. In order to offset these costs, airlines must achieve high passenger load factors. Charter airlines have the advantage over scheduled airlines, in that they will only fly if a minimum level of people has pre-booked seats. Two aeroplanes were chosen for comparison purpose： an Airbus A 340-300 and a Boeing 767-300ER. The private benefits calculated were based on load factors between 80 and 95 percent for ticket prices of USD 667 and USD 773. In addition, to private costs and benefits, social benefits were also estimated in the form of additional secondary revenue generated. With the introduction of net social benefits, both projects become profitable. A 50 percent substitution of revenue generated by the Charter tourists reduces the profits for the both projects drastically. A project based on a Boeing 767-300ER is the most efficient project as it has the highest NPV and BCR values. A reduction in the lease cost of the Airbus 340-300 could make projects based on it more competitive. A few constraints on the establishment of a Charter airline operator based in Port Elizabeth are： the lack of adequate runway for the landing of the long-haul carriers and the need of a larger liberalisation of the aviation policy by eliminating protectionism. The cost benefit analysis undertaken in this research does not take into account social costs and benefits to the economy of establishing a Charter airline based in Port Elizabeth, such as an employment, infrastructure development and poverty alleviation. Nevertheless the analysis does suggest that there are strong private and social benefits warranting the establishment of an airline business between Europe and Port Elizabeth. The economic benefits of the tourism industry and its link to airline travel are outlined in section 3. It is shown that the growth of the airline industry is a major component and contributor to tourism growth.展开更多
ON the night of June 1,2015,a tornado overturned a craiseship carrying 454 people on the Yangtze River in Hubei Province.The ship,Eastern Star,was owned by the Chongqing Eastern Shipping Corporation,and passengers had...ON the night of June 1,2015,a tornado overturned a craiseship carrying 454 people on the Yangtze River in Hubei Province.The ship,Eastern Star,was owned by the Chongqing Eastern Shipping Corporation,and passengers had booked their trip through a travel agency in Shanghai.Chinese Premier Li Keqiang rushed to the site the next morning and gave instmctions for the coordination of the search and rescue effort.展开更多
With the continuous growth of civil aviation passenger traffic, airlines and airports must constantly improve the level of operation and management, in order to meet the high quality and the high level of passenger de...With the continuous growth of civil aviation passenger traffic, airlines and airports must constantly improve the level of operation and management, in order to meet the high quality and the high level of passenger demand for personalized service. This paper puts forward that the airport passenger personalized service system in the era of big data, which can achieve high precision indoor and outdoor positioning seamless switch through using the integration of GPS and Beacon technology. Personalized service client for mobile intelligent terminal was developed to provide more convenient, efficient, dynamic and personalized airport information service for airport passenger.展开更多
Taxi drivers' cruising patterns are learnt with GPS trajectory data collected in Shenzhen, China. By employing Ripley's K function, the impacts of land use and pick-up experience on taxis' cruising behavio...Taxi drivers' cruising patterns are learnt with GPS trajectory data collected in Shenzhen, China. By employing Ripley's K function, the impacts of land use and pick-up experience on taxis' cruising behavior are investigated concerning about both intensity of influence and radius of influence. The results indicate that, in general, taxi drivers tend to learn more from land use characteristics than from pick-up experience. The optimal radius of influence of land use points and previous pick-up points is 14.18 km and 9.93 km, respectively. The findings also show that the high-earning drivers or thorough drivers pay more attention to land use characteristics and tend to cruise in high-density area, while the low-earning drivers or focus drivers prefer to learn more from previous pick-up experience and select the area which is far away from the high-density area. These findings facilitate the development of measures of managing taxi's travel behavior by providing useful insights into taxis' cruising patterns. The results also provide useful advice for taxi drivers to make efficient cruising decision, which will contribute to the improvement of cruising efficiency and the reduction of negative effects.展开更多
In recent years, the world economic situation and container shipping industry has been fluctuated drastically, which has complicated the liner shipping companies＇ operation. The conventional issue of overcapacity due...In recent years, the world economic situation and container shipping industry has been fluctuated drastically, which has complicated the liner shipping companies＇ operation. The conventional issue of overcapacity due to the ＂equipment battle＂, and the destructive competition have further stimulated the operating intricacy within the container sector. That would be interesting to explore the chartering strategies of CMA CGM （Compagnie Maritime d＇Affretement Compagnie Generale Maritime） in such a volatile market as any capacity adjustment dictates a line＇s profit line. Nevertheless, the usefulness of ship chartering is not only confined to the operational level but also the strategic level. Throughout the analysis of CMA CGM＇s fleet trend, fleet deployment as well as chartering activities, it can illustrate the above concepts and observe a little bit further about the strategic movement of CMA CGM.展开更多
文摘In this paper, a mathematical model about the optimal booking level problem in airline overbooking rnanageanent is proposed. Firstly, the normal distribution is employed to approximate Poisson requests and binomial goshows. By calculating the mean loss, a model to describe the relationship between booking level and flight revenue is established. Then, an equation is deduced to decide the optimal booking level. Finally, a numerical example is utilized to illustrate the proposed model and discuss the impact of refund rate on the optimal booking level and the mean loss.
文摘1930s was the golden age for the flying-boat airlines in the world, notably the Pan Am Clipper transpacific and transatlantic routes, and the （British） Imperial Airways UK-Africa and UK-Australia/Far East routes. The major advantage of the flying boats was its endless runway （i.e., ocean or lake） and resultant possibilities for larger aircrafts than land-based airliners. Airlines such as Pan Am made large investments in the 1930s for flying boats, their special terminals by the water, and the worldwide flying-boat air route network. However, in the late 1940s to early 1950s, the flying boats suddenly disappeared due to the rapid development of land-based large airliners and long runways, according to the previous studies. The author conducted historical research on this topic, and found another reason： rapid decline in the high-income population who used to travel by flying boat scheduled flights. Also found was a recent surge of the luxury market, and steady increase in the cruise-ship passengers. Hence, there could be implications for revival of the flying boat flights as luxury cruise, rather than as scheduled flights.
文摘In underground constructions, a good ventilation design not only delivers fresh air to establish good working environment, but also provides a scientific and reliable basis to prevent disasters. In emergency cases, unexpected closure of the main airways may occur, providing the workers with alternative airways is substantial. This is important not only to sustain personnel lives, but also to prevent the mine ventilation system from damage. In this research, alternate solutions were introduced in case of failure in the underground construction to keep a pre-assigned fixed quantity in a working place for mine ventilation network. Eight different collapse scenarios were proposed to study their effect on the air quantity distribution among the branches in the ventilation circuit. From these scenarios, it is found that providing a sufficient air quantity in the working places could be achieved through modification of the network topology and adjusting the values of the regulators pressure. It is also indicated that the distance between the collapse and working places has a great effect on the amount of air delivered to it. A reduction in the power consumption could be done by re-arrange the installed regulators and decreasing the number of nodes and branches inside the network. A relationship representing the effect of changing the network topology on the total network power consumption was deduced through regression analysis. It is found that the total network power is quadratic dependent on the number of regulators and number of branches while it is directly dependent on the regulator power.
基金Project(51178466) supported by the National Natural Science Foundation of ChinaProject(200545) supported by the Foundation for the Author of National Excellent Doctoral Dissertation of ChinaProject(2011JQ006) supported by the Fundamental Research Funds of the Central Universities of China
文摘To investigate airflow pattern and its impact on particle deposition, finite-volume based computational fluid dynamics （CFD） simulations were conducted in the diseased triple-bifitrcation airways. Computations were carried out for twenty Reynolds numbers ranging from 100 to 2 000 in the step of 100. Particles in the size range of 1-10 μm were conducted. Two particle deposition mechanisms （gravitational sedimentation and inertial impaction） were considered. The results indicate that there are strong relationship between airflow structures and particle deposition patterns. Deposition efficiency is different for different particles in the whole range of the respiratory rates. Particles in different sizes can deposit at different sites. Smaller particles can be uniformly deposited at the inside wall of the considered model. Larger particles can be mainly deposited in the proximal bifurcations. Deposition fraction varies a lot for different inlet Reynolds numbers. For lower Reynolds numbers, deposition fraction is relatively small and varies a little with varying the diameters. For Reynolds number to target the aerosols at the specific site. higher Reynolds numbers, there is a most efficient diameter for each
基金supported by the National Natural Science Foundation of China(Grant Nos.51478056 and 51208202)
文摘This study is to explore a suitable method to classify landform, in order to support the decision making for community siting in mountainous areas.It first proposes the landform classification for community siting(LCCS) method with detailed discussions on its rationality and the chosen parameters.This method is then tested and verified in Quxian county.The LCCS method entails twograde parameters, which uses relative relief as the first grading parameter, slope as the second, followed by a synthesis process to form a suitable landform classification system.By applying the LCCS method in Quxian county, the result shows that its use of watershed to identify geomorphometric units, and its use of the altitude datum concept, can effectively classify landform according to the local cultural traditions, and the economic and environmental conditions.The verification result shows that comparing to the conventional methods, the LCCS method respects to people's daily experience due to its bottom-up approach.It not only help to minimize the disturbance to the nature when choosing locations for community development, but also helps to prepare more precise land management policies,which maximizes agricultural production and minimizes terrain transformation.
文摘For the last 10 years,the Venezuelan aerospace industry has been constantly growing,and it is to be expected to continue in the same way in the future.China and its space industry,as the main partner for most of the ongoing Venezuelan space projects from their beginning,has been an important player in their development and may continue acting as one of the most important partners not only for the Venezuelan aerospace industry but also for other Latin-American countries' aerospace industries.ABAE(Bolivarian Agency for Space Activities) together with the related Chinese aerospace companies,with the guidance and help of CGWIC,has been constantly improving its cooperation methods,regarding technical work flows as well as management activities,especially for the latest's space projects under development,namely the CIDE(Venezuelan Design,Assembly,Integration and Testing Center) and VRSS-2(Venezuelan Remote Sensing Satellite-2) programs.Provided that there is a deeper and stronger cooperation in the future,partnership and friendship of the different scientists,experts and leaders from the space sectors of both countries,will be improved and strengthened for the development of both nations social welfare.
文摘The tourist industry, as global mass phenomenon, is inextricably linked to the evolution of air transport systems and air carriers, in turn, depends on tourism to ensure stability in routes and prices. Therefore, both sectors must face the new challenges together, the transport industry is heading a problem of energy and cost overruns, that inevitably will affect tourism in the short term. The first energy crisis that they are starting to live, has been mitigated by changes in three parameters： （1） the international regulation of commercial aviation; （2） the connectivity and business （birth of low cost companies） models; and （3） the new policies for climate change and gas emission. So far, the rapid growth of the tourist industry has being held on a fast and cheap access to transport energy resources based on the false belief of unlimited access to energy. The article is a review of the state of the art, and the research papers published on air transportation, relating to tourism and the emergence of low cost airlines, in order to give a global vision for the decision makers of mass destinations, as it is the case of the Canary Islands that we will use as a reference.
文摘Tourism is becoming a vital component for economic development in South Africa. The income generated by the tourism industry is about 6% of the GDP, which is significant but still falls short of the goal set by the White Paper on Tourism in 2000. In the light of South Africa hosting the 2010 Football World Cup, it is important to identify ways of sustainable tourism development that would continue to increase the benefits to the economy long after the event＇s over. The main objective of the research was to explore an idea for increasing the level of tourist income generated in the Port Elizabeth （Eastern Cape） area. The idea was researched by means of conducting a cost-benefit analysis of two tourist related projects. These projects would introduce Charter airline services between Europe and Port Elizabeth. A second objective was to identify constraints on the project or market failures which would prevent their implementation. The economic theory behind the operation of an airline showed that lease costs and aeroplane operating costs are the two most important factors determine Charter airline＇s profitability. In order to offset these costs, airlines must achieve high passenger load factors. Charter airlines have the advantage over scheduled airlines, in that they will only fly if a minimum level of people has pre-booked seats. Two aeroplanes were chosen for comparison purpose： an Airbus A 340-300 and a Boeing 767-300ER. The private benefits calculated were based on load factors between 80 and 95 percent for ticket prices of USD 667 and USD 773. In addition, to private costs and benefits, social benefits were also estimated in the form of additional secondary revenue generated. With the introduction of net social benefits, both projects become profitable. A 50 percent substitution of revenue generated by the Charter tourists reduces the profits for the both projects drastically. A project based on a Boeing 767-300ER is the most efficient project as it has the highest NPV and BCR values. A reduction in the lease cost of the Airbus 340-300 could make projects based on it more competitive. A few constraints on the establishment of a Charter airline operator based in Port Elizabeth are： the lack of adequate runway for the landing of the long-haul carriers and the need of a larger liberalisation of the aviation policy by eliminating protectionism. The cost benefit analysis undertaken in this research does not take into account social costs and benefits to the economy of establishing a Charter airline based in Port Elizabeth, such as an employment, infrastructure development and poverty alleviation. Nevertheless the analysis does suggest that there are strong private and social benefits warranting the establishment of an airline business between Europe and Port Elizabeth. The economic benefits of the tourism industry and its link to airline travel are outlined in section 3. It is shown that the growth of the airline industry is a major component and contributor to tourism growth.
文摘ON the night of June 1,2015,a tornado overturned a craiseship carrying 454 people on the Yangtze River in Hubei Province.The ship,Eastern Star,was owned by the Chongqing Eastern Shipping Corporation,and passengers had booked their trip through a travel agency in Shanghai.Chinese Premier Li Keqiang rushed to the site the next morning and gave instmctions for the coordination of the search and rescue effort.
文摘With the continuous growth of civil aviation passenger traffic, airlines and airports must constantly improve the level of operation and management, in order to meet the high quality and the high level of passenger demand for personalized service. This paper puts forward that the airport passenger personalized service system in the era of big data, which can achieve high precision indoor and outdoor positioning seamless switch through using the integration of GPS and Beacon technology. Personalized service client for mobile intelligent terminal was developed to provide more convenient, efficient, dynamic and personalized airport information service for airport passenger.
基金Project(NCET-14-0318) supported by the Humanity and Social Science Youth Foundation of Ministry of Education,ChinaProject supported by the Training Program for Outstanding Young Teachers in Jilin University,ChinaProject(2014M551191) supported by China Postdoctoral Science Foundation
文摘Taxi drivers' cruising patterns are learnt with GPS trajectory data collected in Shenzhen, China. By employing Ripley's K function, the impacts of land use and pick-up experience on taxis' cruising behavior are investigated concerning about both intensity of influence and radius of influence. The results indicate that, in general, taxi drivers tend to learn more from land use characteristics than from pick-up experience. The optimal radius of influence of land use points and previous pick-up points is 14.18 km and 9.93 km, respectively. The findings also show that the high-earning drivers or thorough drivers pay more attention to land use characteristics and tend to cruise in high-density area, while the low-earning drivers or focus drivers prefer to learn more from previous pick-up experience and select the area which is far away from the high-density area. These findings facilitate the development of measures of managing taxi's travel behavior by providing useful insights into taxis' cruising patterns. The results also provide useful advice for taxi drivers to make efficient cruising decision, which will contribute to the improvement of cruising efficiency and the reduction of negative effects.
文摘In recent years, the world economic situation and container shipping industry has been fluctuated drastically, which has complicated the liner shipping companies＇ operation. The conventional issue of overcapacity due to the ＂equipment battle＂, and the destructive competition have further stimulated the operating intricacy within the container sector. That would be interesting to explore the chartering strategies of CMA CGM （Compagnie Maritime d＇Affretement Compagnie Generale Maritime） in such a volatile market as any capacity adjustment dictates a line＇s profit line. Nevertheless, the usefulness of ship chartering is not only confined to the operational level but also the strategic level. Throughout the analysis of CMA CGM＇s fleet trend, fleet deployment as well as chartering activities, it can illustrate the above concepts and observe a little bit further about the strategic movement of CMA CGM.
