The similarities and differences between the container terminal logistics system(CTLS)and the Harvard-architecture computer system are compared in terms of organization and architecture.The mapping relation and the mo...The similarities and differences between the container terminal logistics system(CTLS)and the Harvard-architecture computer system are compared in terms of organization and architecture.The mapping relation and the modeling framework of the CTLS are presented based on multi-agent,and the successful algorithms in the computer domain are applied to the modeling framework,such as the dynamic priority and multilevel feedback scheduling algorithm.In addition,a model and simulation on a certain quay at Shanghai harbor is built up on the AnyLogic platform to support the decision-making of terminal on service cost.It validates the feasibility and creditability of the above systematic methodology.展开更多
An integrated model is presented to schedule the container handling system. The objective is to improve the coop- eration between different types of equipments, and to increase the productivity of the terminal. The pr...An integrated model is presented to schedule the container handling system. The objective is to improve the coop- eration between different types of equipments, and to increase the productivity of the terminal. The problem is formulated as a Hybrid Flow Shop Scheduling problem with precedence constraint, setup times and blocking (HFSS-B). A tabu search algorithm is proposed to solve this problem. The quality and efficiency of the proposed algorithm is analyzed from the computational point of view.展开更多
Experimental investigations have been carried out to study morpho-hydraulic characteristics such as scour geometry and turbulent flow properties around tandem piers in alluvial channels. Experiments were carried out i...Experimental investigations have been carried out to study morpho-hydraulic characteristics such as scour geometry and turbulent flow properties around tandem piers in alluvial channels. Experiments were carried out in a plane sand bed with two circular piers of same diameter arranged in tandem manner under no seepage, 10% seepage and 20% seepage conditions. Downward seepage minimizes the scour depth around piers and restrains the development of scour depth with time. Strong reversal flow is found near the bed at upstream of piers and near free surface at downstream of piers where velocity and Reynolds shear stress are found to be negative which reduce in magnitude with downward seepage. The flow is more critical within the gap between two piers where velocity is lesser near free surface and gradually increasing towards bed. Quadrant analysis shows that contribution of each event to the total Reynolds shear stress increases with downward seepage. Sedimentation effect prevails within the scour hole whereas outside the scour hole erosive forces become more dominant. Reduced reversal flow at upstream of pier because of downward seepage results in decreasing higher order moments and turbulent kinetic energy. At downstream of piers, secondary currents are dominant due to wake vortices. Strouhal number decreases in case of seepage runs than no seepage condition.展开更多
To evaluate the relationship between salinity tolerance and genetic diversity of plankton,we collected a wild species of plankton from Taipingjiao,Qingdao.The fragment of ITS1-5.8S rDNA-ITS2 was extracted and sequence...To evaluate the relationship between salinity tolerance and genetic diversity of plankton,we collected a wild species of plankton from Taipingjiao,Qingdao.The fragment of ITS1-5.8S rDNA-ITS2 was extracted and sequenced.The results showed that the plankton belongs to Oxyrrhis marina.The salinity tolerance of O.marina ranges from 4 to 60.Seven selected groups were built up to evaluate salinity tolerance and to assess genetic diversity by RAPD.The salinity tolerance comparison revealed considerable differences among groups:the strains of O.marina in group 4 could survive under salinity from 4 to 32,while the strains selected for salinity 60 died under the salinity lower than 16.Analysis of genetic diversity of the seven groups showed that the mean genetic diversity index value was 0.28,but it was only 0.16 in selected group of 4 and was 0.24 for group 60.The result of AMOVA suggested a significantly positive relationship between the salinity tolerance and genetic diversity of O.marina (P<0.01).This study indicates that consideration of intraspecific genetic divergence in O.marina might be indispensable when using it as a model in the study of salinity tolerance of wild plankton.展开更多
We present a GIS-based habitat suitability index(HSI) model to identify suitable areas for Zostera marina L. restoration in the subtidal zone of Xiaoheishan Island. The controlling factors in the model,in order of imp...We present a GIS-based habitat suitability index(HSI) model to identify suitable areas for Zostera marina L. restoration in the subtidal zone of Xiaoheishan Island. The controlling factors in the model,in order of importance,are Secchi depth,sediment composition,water temperature,salinity,current velocity,water depth and nutrient quality. Specific factor piecewise functions have been used to transform parameter values into normalized quality indexes. The weight of each factor was defined using expert knowledge and the analytic hierarchy process(AHP) method. All of the data thus obtained were interpolated using the inverse distance weighted(IDW) interpolation method to create maps for the entire region. In this study,the analysis of habitat suitability in the subtidal zone of Xiaoheishan Island was conducted for four seasons. According to the GIS-based HSI model,the optimal habitat of Z ostera marina L. appears in spring,although habitat remains suitable all year round. On the whole,the optimum site for eelgrass restoration is located in the eastern region,followed by the western and southern regions. We believe that the GIS-based HSI model could be a promising tool to select sites for Z ostera marina L. restoration and could also be applicable in other types of habitat evaluation.展开更多
An optimization model for scheduling of quay cranes (QCs) and yard trailers was proposed to improve the overall efficiency of container terminals. To implement this model, a two-phase tabu search algorithm was designe...An optimization model for scheduling of quay cranes (QCs) and yard trailers was proposed to improve the overall efficiency of container terminals. To implement this model, a two-phase tabu search algorithm was designed. In the QCs scheduling phase of the algorithm, a search was performed to determine a good QC unloading operation order. For each QC unloading operation order generated during the QC's scheduling phase, another search was run to obtain a good yard trailer routing for the given QC's unloading order. Using this information, the time required for the operation was estimated, then the time of return to availability of the units was fed back to the QC scheduler. Numerical tests show that the two-phase Tabu Search algorithm searches the solution space efficiently, decreases the empty distance yard trailers must travel, decreases the number of trailers needed, and thereby reduces time and costs and improves the integration and reliability of container terminal operation systems.展开更多
This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/...This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/2 000 kVA) for the quay cranes is used for the power input of the system, after frequency and voltage converting (450 V/60 Hz), then putting out and supplying to vessel. This system is flexible with positive effect on energy-saving and emission reduction; besides, there's no requirement of civil reconstruction to container terminals, which is suitable for the busy ports in China.展开更多
Secure storage yard is one of the optimal core goals of container transportation;thus,making the necessary storage arrangements has become the most crucial part of the container terminal management systems(CTMS).Thi...Secure storage yard is one of the optimal core goals of container transportation;thus,making the necessary storage arrangements has become the most crucial part of the container terminal management systems(CTMS).This paper investigates a random hybrid stacking algorithm(RHSA) for outbound containers that randomly enter the yard.In the first stage of RHSA,the distribution among blocks was analyzed with respect to the utilization ratio.In the second stage,the optimization of bay configuration was carried out by using the hybrid genetic algorithm.Moreover,an experiment was performed to test the RHSA.The results show that the explored algorithm is useful to increase the efficiency.展开更多
We investigated the allelopathic properties of Alexandrium tamarense(Laboar) Balech on the growth of Prorocentrum donghaiense Lu,Chattonella marina(Subrahmanyan) Hara et Chihara and Heterosigma akashiwo(Hada) Hada in ...We investigated the allelopathic properties of Alexandrium tamarense(Laboar) Balech on the growth of Prorocentrum donghaiense Lu,Chattonella marina(Subrahmanyan) Hara et Chihara and Heterosigma akashiwo(Hada) Hada in a laboratory experiment.We examined the growth of A.tamarense,C.marina,P.donghaiense and H.Akashiwo in co-cultures and the effect of filtrates from A.tamarense cultures in various growth phases,on the three harmful algal bloom(HAB)-forming algae.In co-cultures with A.tamarense,both C.marina and H.akashiwo were dramatically suppressed at high cell densities;in contrast,the growth of P.donghaiense varied in different inoculative ratios of A.tamarense and P.donghaiense.When the ratio was 1:1(P.donghaiense:A.tamarense),growth of P.donghaiense was inhibited considerably,while the growth of P.donghaiense was almost the same as that of the control when the ratio was 9:1.The growth difference of P.donghaiense,C.marina and H.akashiwo when co-cultured with A.tamarense indicated that the allelopathic effect may be one of the important factors in algal competition and phytoplankton succession involving A.tamarense.In addition,the filtrate from A.tamarense culture had negative impacts on these three HAB algae,and such inhibition varied with different growth phases of A.tamarense in parallel with reported values of PSP toxin content in Alexandrium cells.This implied that PSP toxin was possibly involved in allelopathy of A.tamarense.However,the rapid decomposition and inactivation of PSP toxin above pH7 weakened this possibility.Further studies on the allelochemicals responsible for the allelopathy of A.tamarense need to be carried out in future.展开更多
This paper extends a prediction model for multi-directional random wave transformation based on an energy balance equation by Mase with the consideration of wave shoaling, refraction, diffraction, reflection and break...This paper extends a prediction model for multi-directional random wave transformation based on an energy balance equation by Mase with the consideration of wave shoaling, refraction, diffraction, reflection and breaking. This numerical model is improved by 1) introducing Wen's frequency spectrum and Mitsuyasu's directional function, which are more suitable to the coastal area of China; 2) considering energy dissipation caused by bottom friction, which ensures more accurate results for large-scale and shallow water areas; 3) taking into account a non-linear dispersion relation. Predictions using the extended wave model are carried out to study the feasibility of constructing the Ai Hua yacht port in Qingdao, China, with a comparison between two port layouts in design. Wave fields inside the port for different incident wave directions, water levels and return periods are simulated, and then two kinds of parameters are calculated to evaluate the wave conditions for the two layouts. Analyses show that Layout I is better than Layout II. Calculation results also show that the harbor will be calm for different wave directions under the design water level. On the contrary, the wave conditions do not wholly meet the requirements of a yacht port for ship berthing under the extreme water level. For safety consideration, the elevation of the breakwater might need to be properly increased to prevent wave overtopping under such water level. The extended numerical simulation model may provide an effective approach to computing wave heights in a harbor.展开更多
In the Pearl River Delta (PRD), there is severe competition between container ports, particularly those in Hong Kong, Shenzhen, and Guangzhou, for collecting international maritime container cargo. In addition, the se...In the Pearl River Delta (PRD), there is severe competition between container ports, particularly those in Hong Kong, Shenzhen, and Guangzhou, for collecting international maritime container cargo. In addition, the second phase of the Nansha terminal in Guangzhou’s port and the first phase of the Da Chang Bay container terminal in Shenzhen opened last year. Under these circumstances, there is an increasing need to quantitatively measure the impact these infrastructure investments have on regional cargo flows. The analysis should include the effects of container terminal construction, berth deepening, and access road construction. The authors have been developing a model for international cargo simulation (MICS) which can simulate the movement of cargo. The volume of origin-destination (OD) container cargo in the East Asian region was used as an input, in order to evaluate the effects of international freight transportation policies. This paper focuses on the PRD area and, by incorporating a more detailed network, evaluates the impact of several infrastructure investment projects on freight movement.展开更多
To promote the construction of Shanghai international shipping center, the planneu new acepwatcr terminal construction in Hengsha pushes forward the innovation and breakthroughs of the existing port manage- ment syste...To promote the construction of Shanghai international shipping center, the planneu new acepwatcr terminal construction in Hengsha pushes forward the innovation and breakthroughs of the existing port manage- ment system and building mechanisms. Through reviewing, analyzing, comparing and summarizing the suc- cessful experience of the major ports at home and abroad, market-oriented recommendations will be proposed in terms of effectiveness and feasibility, as well as the idea of"Shanghai Freeport".展开更多
Understanding coal mine rib behavior is important for inferring pillar loading conditions as well as ensuring the safety of miners who are regularly exposed to ribs. Due to the variability in the geometry of undergrou...Understanding coal mine rib behavior is important for inferring pillar loading conditions as well as ensuring the safety of miners who are regularly exposed to ribs. Due to the variability in the geometry of underground openings and ground behavior, point measurements often fail to capture the true movement of mine workings. Photogrammetry is a potentially fast, cheap, and precise supplemental measurement tool in comparison to extensometers, tape measures, or laser range meters, but its application in underground coal has been limited. The practical use of photogrammetry was tested at the Safety Research Coal Mine, National Institute for Occupational Safety and Health(NIOSH). A commercially available, digital single-lens reflex(DSLR) camera was used to perform the photogrammetric surveys for the experiment. Several experiments were performed using different lighting conditions, distances to subject,camera settings, and photograph overlaps, with results summarized as follows: the lighting method was found to be insignificant if the scene was appropriately illuminated. It was found that the distance to the subject has a minimal impact on result accuracy, and that camera settings have a significant impact on the photogrammetric quality of images. An increasing photograph resolution was preferable when measuring plane orientations; otherwise a high point cloud density would likely be excessive. Focal ratio(F-stop) changes affect the depth of field and image quality in situations where multiple angles are necessary to survey cleat orientations. Photograph overlap is very important to proper three-dimensional reconstruction, and at least 60% overlap between photograph pairs is ideal to avoid unnecessary post-processing. The suggestions and guidelines proposed are designed to increase the quality of photogrammetry inputs and outputs as well as minimize processing time, and serve as a starting point for an underground coal photogrammetry study.展开更多
Containerization with its increasing share in seaborne trade highlights the importance of assessing container terminals performance indicators. The world economical situation and the global container market have impro...Containerization with its increasing share in seaborne trade highlights the importance of assessing container terminals performance indicators. The world economical situation and the global container market have improved slightly after the 2008 world economical crises. Egyptian container terminals are important to serve the world liner services in particular the main east-west routes. Egypt is considered the leading country in Africa and the 18th worldwide in serving the liner markets. Alexandria container terminal as a medium size terminal shows an acceptable super/infra structure facilities and throughput. The analysis of Alexandria container terminal performance indicators from 2007 to 2011 shows a slightly progressive trend. Selected indicators, reflecting production, productivity, utilization and service measures, were used according to the available data. Terminal production shows a slight increasing demand concerning number of vessels and TEUs (Twenty Equivalent Units). Furthermore, productivity indicators proved remarkable development in moves per working hours rather than moves per hours in port, deducing lack of port services accompanying cargo handling. Moreover, Utilization measurements show the terminal occupancy ratio fluctuating from 45% to 67% with slight development. Finally, Service measures show progress in vessels turnaround time, while long wasted time consumed in processes rather than operation was observed.展开更多
Nowadays, the most prominent risk assessment techniques are founded on the values of measuring and controlling the frequency and the consequences of risks in order to assure an "acceptable level" of "safeness" mai...Nowadays, the most prominent risk assessment techniques are founded on the values of measuring and controlling the frequency and the consequences of risks in order to assure an "acceptable level" of "safeness" mainly in the lines of environmental, health and hygiene and port product issues. This paper initially introduces risk assessment approaches within the emerging role of ports Thereafter, it qualitatively assesses their potential for ports by discussing issues challenging every safety and security approach within the maritime industry such as proactiveness, organization, transparency, cost-effectiveness and, when possible, calibration to specific experiences. Moreover, an empirical study was conducted in order to provide evidence for formal risk assessment for safety and security in the main Greek port container terminals of Piraeus and Thessaloniki. The empirical research is based on in-depth semi-structured interviews with the administrations of container terminals. The results include important findings, regarding the likelihood of appearance of certain risks and their perceived severity in Greek container terminals. The collected answers and their analysis are also important for confirming the suggested theoretical formal risk assessment framework for ports.展开更多
基金The National Key Technology R&D Program of China during the 11th Five-Year Plan Period(No.2006BAH02A06)
文摘The similarities and differences between the container terminal logistics system(CTLS)and the Harvard-architecture computer system are compared in terms of organization and architecture.The mapping relation and the modeling framework of the CTLS are presented based on multi-agent,and the successful algorithms in the computer domain are applied to the modeling framework,such as the dynamic priority and multilevel feedback scheduling algorithm.In addition,a model and simulation on a certain quay at Shanghai harbor is built up on the AnyLogic platform to support the decision-making of terminal on service cost.It validates the feasibility and creditability of the above systematic methodology.
文摘An integrated model is presented to schedule the container handling system. The objective is to improve the coop- eration between different types of equipments, and to increase the productivity of the terminal. The problem is formulated as a Hybrid Flow Shop Scheduling problem with precedence constraint, setup times and blocking (HFSS-B). A tabu search algorithm is proposed to solve this problem. The quality and efficiency of the proposed algorithm is analyzed from the computational point of view.
文摘Experimental investigations have been carried out to study morpho-hydraulic characteristics such as scour geometry and turbulent flow properties around tandem piers in alluvial channels. Experiments were carried out in a plane sand bed with two circular piers of same diameter arranged in tandem manner under no seepage, 10% seepage and 20% seepage conditions. Downward seepage minimizes the scour depth around piers and restrains the development of scour depth with time. Strong reversal flow is found near the bed at upstream of piers and near free surface at downstream of piers where velocity and Reynolds shear stress are found to be negative which reduce in magnitude with downward seepage. The flow is more critical within the gap between two piers where velocity is lesser near free surface and gradually increasing towards bed. Quadrant analysis shows that contribution of each event to the total Reynolds shear stress increases with downward seepage. Sedimentation effect prevails within the scour hole whereas outside the scour hole erosive forces become more dominant. Reduced reversal flow at upstream of pier because of downward seepage results in decreasing higher order moments and turbulent kinetic energy. At downstream of piers, secondary currents are dominant due to wake vortices. Strouhal number decreases in case of seepage runs than no seepage condition.
文摘To evaluate the relationship between salinity tolerance and genetic diversity of plankton,we collected a wild species of plankton from Taipingjiao,Qingdao.The fragment of ITS1-5.8S rDNA-ITS2 was extracted and sequenced.The results showed that the plankton belongs to Oxyrrhis marina.The salinity tolerance of O.marina ranges from 4 to 60.Seven selected groups were built up to evaluate salinity tolerance and to assess genetic diversity by RAPD.The salinity tolerance comparison revealed considerable differences among groups:the strains of O.marina in group 4 could survive under salinity from 4 to 32,while the strains selected for salinity 60 died under the salinity lower than 16.Analysis of genetic diversity of the seven groups showed that the mean genetic diversity index value was 0.28,but it was only 0.16 in selected group of 4 and was 0.24 for group 60.The result of AMOVA suggested a significantly positive relationship between the salinity tolerance and genetic diversity of O.marina (P<0.01).This study indicates that consideration of intraspecific genetic divergence in O.marina might be indispensable when using it as a model in the study of salinity tolerance of wild plankton.
基金Supported by the Key Laboratory of Marine Ecology and Environmental Science and Engineering,SOA(No.MESE-2013-01)the National Natural Science Foundation of China(No.41206102)the National Marine Public Welfare Research Project(No.201305009)
文摘We present a GIS-based habitat suitability index(HSI) model to identify suitable areas for Zostera marina L. restoration in the subtidal zone of Xiaoheishan Island. The controlling factors in the model,in order of importance,are Secchi depth,sediment composition,water temperature,salinity,current velocity,water depth and nutrient quality. Specific factor piecewise functions have been used to transform parameter values into normalized quality indexes. The weight of each factor was defined using expert knowledge and the analytic hierarchy process(AHP) method. All of the data thus obtained were interpolated using the inverse distance weighted(IDW) interpolation method to create maps for the entire region. In this study,the analysis of habitat suitability in the subtidal zone of Xiaoheishan Island was conducted for four seasons. According to the GIS-based HSI model,the optimal habitat of Z ostera marina L. appears in spring,although habitat remains suitable all year round. On the whole,the optimum site for eelgrass restoration is located in the eastern region,followed by the western and southern regions. We believe that the GIS-based HSI model could be a promising tool to select sites for Z ostera marina L. restoration and could also be applicable in other types of habitat evaluation.
文摘An optimization model for scheduling of quay cranes (QCs) and yard trailers was proposed to improve the overall efficiency of container terminals. To implement this model, a two-phase tabu search algorithm was designed. In the QCs scheduling phase of the algorithm, a search was performed to determine a good QC unloading operation order. For each QC unloading operation order generated during the QC's scheduling phase, another search was run to obtain a good yard trailer routing for the given QC's unloading order. Using this information, the time required for the operation was estimated, then the time of return to availability of the units was fed back to the QC scheduler. Numerical tests show that the two-phase Tabu Search algorithm searches the solution space efficiently, decreases the empty distance yard trailers must travel, decreases the number of trailers needed, and thereby reduces time and costs and improves the integration and reliability of container terminal operation systems.
文摘This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/2 000 kVA) for the quay cranes is used for the power input of the system, after frequency and voltage converting (450 V/60 Hz), then putting out and supplying to vessel. This system is flexible with positive effect on energy-saving and emission reduction; besides, there's no requirement of civil reconstruction to container terminals, which is suitable for the busy ports in China.
基金Supported by the Research Grants from Shanghai Municipal Natural Science Foundation(No.10190502500) Shanghai Maritime University Start-up Funds,Shanghai Science&Technology Commission Projects(No.09DZ2250400) Shanghai Education Commission Project(No.J50604)
文摘Secure storage yard is one of the optimal core goals of container transportation;thus,making the necessary storage arrangements has become the most crucial part of the container terminal management systems(CTMS).This paper investigates a random hybrid stacking algorithm(RHSA) for outbound containers that randomly enter the yard.In the first stage of RHSA,the distribution among blocks was analyzed with respect to the utilization ratio.In the second stage,the optimization of bay configuration was carried out by using the hybrid genetic algorithm.Moreover,an experiment was performed to test the RHSA.The results show that the explored algorithm is useful to increase the efficiency.
基金Supported by the NSFC-Guangdong Province Association Foundation(No.U0733006)the National Natural Science Foundation of China(No.30970502,40976065)the National Basic Research Program of China(973 Program)(No.2010CB428702)
文摘We investigated the allelopathic properties of Alexandrium tamarense(Laboar) Balech on the growth of Prorocentrum donghaiense Lu,Chattonella marina(Subrahmanyan) Hara et Chihara and Heterosigma akashiwo(Hada) Hada in a laboratory experiment.We examined the growth of A.tamarense,C.marina,P.donghaiense and H.Akashiwo in co-cultures and the effect of filtrates from A.tamarense cultures in various growth phases,on the three harmful algal bloom(HAB)-forming algae.In co-cultures with A.tamarense,both C.marina and H.akashiwo were dramatically suppressed at high cell densities;in contrast,the growth of P.donghaiense varied in different inoculative ratios of A.tamarense and P.donghaiense.When the ratio was 1:1(P.donghaiense:A.tamarense),growth of P.donghaiense was inhibited considerably,while the growth of P.donghaiense was almost the same as that of the control when the ratio was 9:1.The growth difference of P.donghaiense,C.marina and H.akashiwo when co-cultured with A.tamarense indicated that the allelopathic effect may be one of the important factors in algal competition and phytoplankton succession involving A.tamarense.In addition,the filtrate from A.tamarense culture had negative impacts on these three HAB algae,and such inhibition varied with different growth phases of A.tamarense in parallel with reported values of PSP toxin content in Alexandrium cells.This implied that PSP toxin was possibly involved in allelopathy of A.tamarense.However,the rapid decomposition and inactivation of PSP toxin above pH7 weakened this possibility.Further studies on the allelochemicals responsible for the allelopathy of A.tamarense need to be carried out in future.
基金supported by the National Natural Science Foundation of China (50879085)the Program for New Century Excellent Talents in University(NCET-07-0778)Fundamental Research Funds for the Central Universities (2012QNA4020)
文摘This paper extends a prediction model for multi-directional random wave transformation based on an energy balance equation by Mase with the consideration of wave shoaling, refraction, diffraction, reflection and breaking. This numerical model is improved by 1) introducing Wen's frequency spectrum and Mitsuyasu's directional function, which are more suitable to the coastal area of China; 2) considering energy dissipation caused by bottom friction, which ensures more accurate results for large-scale and shallow water areas; 3) taking into account a non-linear dispersion relation. Predictions using the extended wave model are carried out to study the feasibility of constructing the Ai Hua yacht port in Qingdao, China, with a comparison between two port layouts in design. Wave fields inside the port for different incident wave directions, water levels and return periods are simulated, and then two kinds of parameters are calculated to evaluate the wave conditions for the two layouts. Analyses show that Layout I is better than Layout II. Calculation results also show that the harbor will be calm for different wave directions under the design water level. On the contrary, the wave conditions do not wholly meet the requirements of a yacht port for ship berthing under the extreme water level. For safety consideration, the elevation of the breakwater might need to be properly increased to prevent wave overtopping under such water level. The extended numerical simulation model may provide an effective approach to computing wave heights in a harbor.
文摘In the Pearl River Delta (PRD), there is severe competition between container ports, particularly those in Hong Kong, Shenzhen, and Guangzhou, for collecting international maritime container cargo. In addition, the second phase of the Nansha terminal in Guangzhou’s port and the first phase of the Da Chang Bay container terminal in Shenzhen opened last year. Under these circumstances, there is an increasing need to quantitatively measure the impact these infrastructure investments have on regional cargo flows. The analysis should include the effects of container terminal construction, berth deepening, and access road construction. The authors have been developing a model for international cargo simulation (MICS) which can simulate the movement of cargo. The volume of origin-destination (OD) container cargo in the East Asian region was used as an input, in order to evaluate the effects of international freight transportation policies. This paper focuses on the PRD area and, by incorporating a more detailed network, evaluates the impact of several infrastructure investment projects on freight movement.
基金Shanghai Science and Technology Research Plan(No.13dz1204900)
文摘To promote the construction of Shanghai international shipping center, the planneu new acepwatcr terminal construction in Hengsha pushes forward the innovation and breakthroughs of the existing port manage- ment system and building mechanisms. Through reviewing, analyzing, comparing and summarizing the suc- cessful experience of the major ports at home and abroad, market-oriented recommendations will be proposed in terms of effectiveness and feasibility, as well as the idea of"Shanghai Freeport".
文摘Understanding coal mine rib behavior is important for inferring pillar loading conditions as well as ensuring the safety of miners who are regularly exposed to ribs. Due to the variability in the geometry of underground openings and ground behavior, point measurements often fail to capture the true movement of mine workings. Photogrammetry is a potentially fast, cheap, and precise supplemental measurement tool in comparison to extensometers, tape measures, or laser range meters, but its application in underground coal has been limited. The practical use of photogrammetry was tested at the Safety Research Coal Mine, National Institute for Occupational Safety and Health(NIOSH). A commercially available, digital single-lens reflex(DSLR) camera was used to perform the photogrammetric surveys for the experiment. Several experiments were performed using different lighting conditions, distances to subject,camera settings, and photograph overlaps, with results summarized as follows: the lighting method was found to be insignificant if the scene was appropriately illuminated. It was found that the distance to the subject has a minimal impact on result accuracy, and that camera settings have a significant impact on the photogrammetric quality of images. An increasing photograph resolution was preferable when measuring plane orientations; otherwise a high point cloud density would likely be excessive. Focal ratio(F-stop) changes affect the depth of field and image quality in situations where multiple angles are necessary to survey cleat orientations. Photograph overlap is very important to proper three-dimensional reconstruction, and at least 60% overlap between photograph pairs is ideal to avoid unnecessary post-processing. The suggestions and guidelines proposed are designed to increase the quality of photogrammetry inputs and outputs as well as minimize processing time, and serve as a starting point for an underground coal photogrammetry study.
文摘Containerization with its increasing share in seaborne trade highlights the importance of assessing container terminals performance indicators. The world economical situation and the global container market have improved slightly after the 2008 world economical crises. Egyptian container terminals are important to serve the world liner services in particular the main east-west routes. Egypt is considered the leading country in Africa and the 18th worldwide in serving the liner markets. Alexandria container terminal as a medium size terminal shows an acceptable super/infra structure facilities and throughput. The analysis of Alexandria container terminal performance indicators from 2007 to 2011 shows a slightly progressive trend. Selected indicators, reflecting production, productivity, utilization and service measures, were used according to the available data. Terminal production shows a slight increasing demand concerning number of vessels and TEUs (Twenty Equivalent Units). Furthermore, productivity indicators proved remarkable development in moves per working hours rather than moves per hours in port, deducing lack of port services accompanying cargo handling. Moreover, Utilization measurements show the terminal occupancy ratio fluctuating from 45% to 67% with slight development. Finally, Service measures show progress in vessels turnaround time, while long wasted time consumed in processes rather than operation was observed.
文摘Nowadays, the most prominent risk assessment techniques are founded on the values of measuring and controlling the frequency and the consequences of risks in order to assure an "acceptable level" of "safeness" mainly in the lines of environmental, health and hygiene and port product issues. This paper initially introduces risk assessment approaches within the emerging role of ports Thereafter, it qualitatively assesses their potential for ports by discussing issues challenging every safety and security approach within the maritime industry such as proactiveness, organization, transparency, cost-effectiveness and, when possible, calibration to specific experiences. Moreover, an empirical study was conducted in order to provide evidence for formal risk assessment for safety and security in the main Greek port container terminals of Piraeus and Thessaloniki. The empirical research is based on in-depth semi-structured interviews with the administrations of container terminals. The results include important findings, regarding the likelihood of appearance of certain risks and their perceived severity in Greek container terminals. The collected answers and their analysis are also important for confirming the suggested theoretical formal risk assessment framework for ports.