Effects of storage block layout and automated yard crane systems on the performance of seaport
OR Spectrum(2012)34:563–591
DOI10.1007/s00291-011-0242-7
REGULAR ARTICLE
Effects of storage block layout and automated yard
crane systems on the performance of seaport container terminals
Nils Kemme
Published online:24February2011
?Springer-Verlag2011
Abstract As a decoupling point between waterside and landside transport,the con-tainer yard plays a major role for the competitiveness of container terminals.One of the latest trends in container yard operations is the automated rail-mounted-gantry-crane system,which offers dense stacking along with high productivity.In this paper,the strategic design of rail-mounted-gantry-crane systems is investigated.A simulation study is conducted to evaluate the effects of four rail-mounted-gantry-crane systems and385yard block layouts—differing in block length,width,and height—on the yard and terminal performance.
Keywords Container terminal·Terminal design·Block dimensions·Automated stacking cranes·Rail-mounted-gantry-crane systems·Simulation
1Introduction
During the last decades,there have been steady growth rates in international trade,and despite the current economic crisis this trend is expected to continue in the long term (Min et al.2009).Along with this development—which is one of the main aspects of the globalization process—there have been huge growth rates for the maritime container shipping industry.Nowadays,the overseas transport of?nished consumer goods is almost always carried out in standardized steel boxes on deep-sea container vessels.In addition,the fraction of liquids as well as piece and bulk goods shipped in specialized containers is also increasing(UNCTAD2008).Capacities and turnovers in the container industry are generally measured in the number of20 containers which N.Kemme(B)
Institute for Operations Research,University of Hamburg,
V on-Melle-Park5,20146Hamburg,Germany
e-mail:nils.kemme@uni-hamburg.de
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Fig.1Container?ow at a seaport container terminal
are called TEU(Twenty-foot Equivalent Unit).Along with the growth in worldwide container transportation,the number and size of ports,as well as the competition among them have increased(Sciomachen and Tanfani2007).This paper focuses on the strategic layout planning of storage yards at seaport container terminals.
A container terminal is an area in the port where vessels are loaded and unloaded and where containers are temporarily stored.In Fig.1,it is illustrated that a container ter-minal is subdivided into several sectors:quay,waterside horizontal transport,storage yard,landside horizontal transport,and gate.At the quay,the vessels are loaded and unloaded by the quay cranes(QCs)which are served by horizontal transport machines. These machines—which are usually straddle carriers(SCs),automated guided vehi-cles(AGVs),or truck-trailer units(TTUs)—carry the containers between QCs and storage yard.The storage yard usually consists of several container blocks which are served by fork lifts,SCs,or gantry cranes.A gantry crane,which is regarded here, can load and unload vehicles that arrive at the yard blocks.Besides,waterside trans-port machines,also landside transport machines arrive at the storage yard.These are usually external trucks(XTs)which enter the container terminal by the gate facilities and which connect the terminal with the hinterland.In addition,a container terminal may have its own railway station.
Altogether,a container can enter the terminal at the quay—which is the waterside interface—by deep-sea or feeder vessel,or at the gate—which is the landside inter-face—by truck or train.Arriving containers are either imported,exported,or trans-shipped at the container terminal.The corresponding container?ows are illustrated in the upper half of Fig.1.An import container arrives by vessel and leaves the terminal by truck or train,while an export container is delivered by XT or train and departs via vessel.Transshipment containers both arrive and depart by vessel.
Container terminals are often faced with several stakeholders who pursue different objectives(Petering2009).From the owners’perspective,the most important stake-holders are in most cases the shipping lines,which are interested in short in-port times of their vessels,since these high investments only earn money when shipping con-tainers at sea.This objective is facilitated by a good productivity of the QCs,which
Effects of storage block layout and automated yard crane systems565 can be measured in the average number of loaded and unloaded containers per QC working hour—this number is called gross crane rate(GCR).Improving the GCR does not only require the optimization of the QC processes,but the whole terminal has to be regarded.In this context,the storage yard is of special importance,since it is not just the storage area for containers;it is the interface between waterside and land-side transport chains.Most of the terminal operations either originate from or cease at the container yard.In addition,along with the ever-increasing container volume, more and more storage capacity is required in the ports.Consequently,land area has become a scarce resource in international container ports(Saanen2004).Therefore, terminal operators are seeking for innovative storage technologies which improve the utilization of storage areas and the GCR at the same time.
The two major trends in stacking equipment are rubber-tyred(RTG)and rail-mounted(RMG)gantry-crane systems(Saanen2004).One of the major advantages of RMG systems—especially for high-labor-cost-countries—is their proven potential for automation.Various types of RMG yards are already in operation or currently under construction at container terminals around the world.These RMG yards are characterized by the used RMG crane system and the layout of the individual yard blocks.Four types of RMG crane systems have been developed—the single,twin, double and triple crane system—mainly differing in the number of cranes per yard block and their crossing ability.
Intuitively,it may be assumed that the usage of more cranes and a better crossing ability,which is connected with more?exibility,lead to better performances.In addi-tion,it may be suggested that increasing the stacking height yields higher performance losses than extending the length or width of the block.Some of these assumptions are con?rmed by isolated studies on crane systems and block layouts(e.g.Saanen and Valkengoed2005;Kim1997).However,so far the relation of crane system and layout effects have not been quanti?ably compared in any study.In particular,the brand-new triple crane system has not been considered in any terminal design study by now. Thus,within the framework of this work,the effects of different RMG crane systems and layout variations on the performance of an RMG yard block are simultaneously analysed.
This paper is organized as follows.In Sect.2,a detailed description of storage yard systems and processes is provided.The relevant literature is summarized in Sect.3. In Sect.4,the simulation model used in this study is described in detail.Numerical experiments and the computational results are presented,analysed,and discussed in Sect.5.Finally,conclusions and further research topics are given in Sect.6.
2Storage yard systems and processes
This paper deals with the strategic planning of storage yards at seaport container ter-minals that are operated by gantry cranes.Because different types and systems of gantry cranes are in operation at container terminals around the world,the research object and the corresponding processes are de?ned in detail within this section.First, known types of gantry-crane systems for container terminals are distinguished.Sec-ondly,strategic variations in terms of system and layout are presented for the regarded
566N.Kemme portal
trolley spreader
bay
tier row/lane
big crane
small crane
Fig.2Example yard block with two gantry cranes
crane type.Thirdly,a discussion of the interrelation of the performances of the yard blocks and the total terminal is given and ?nally,the processes of the regarded crane system are explained.Detailed descriptions of terminal equipment and processes are given by Vis and de Koster (2003),Günther and Kim (2006)as well as Steenken et al.(2004).
2.1Comparison of gantry-crane systems
Each yard block in a container yard that is operated by gantry cranes consists of sev-eral bays,lanes,and tiers.Multiplying these numbers results in the number of storage slots,but this is only a theoretical ?gure as some slots have to be kept free in order to preserve some ?exibility.All lanes of a yard block are located inside the portal of the gantry crane that serves the respective block.In order to access each container in a block,the gantry crane comprises three technical components that enable the crane to move along all three dimensions of the yard block.With the movement of the crane portal,each individual bay of the block can be called upon and the trolley can be moved to the desired lane.Finally,the spreader,which is the hoisting equipment of the crane,can be brought down to the tier where the desired slot is located —but,of course,only slots on top of the pile are directly accessible.In Fig.2,these facts and operations are depicted for an example yard block with two cranes of different sizes.In general,two types of gantry-crane systems have to be distinguished:RTG and RMG crane systems.The portal of an RTG crane moves on rubber tyres,whereas the portal of an RMG moves on rail tracks that are installed alongside a yard block.Consequently,RTG cranes can be moved from one block to another and thereby it is possible to react to different workload situations among the blocks.Hence,the RTG cranes provide more ?exibility than the RMG cranes do.However,along with the ?x-ation to single yard blocks and the loss of ?exibility,more potential for automation is
Effects of storage block layout and automated yard crane systems567 involved for RMGs versus RTGs.Automated RMG cranes,which are also called auto-mated stacking cranes(ASCs)are fully automated in all of their operations and move without any assistance from drivers.However,the handshake between XTs and ASCs is only semi-automated for reasons of occupational safety—it is done by a remote con-troller.Owing to the automation,high investment costs are involved with automated RMG crane systems,which makes this crane type more suitable for high-labor-cost countries.
The arrangement of yard blocks and where the handshake with other modes of trans-portation takes place differ a lot between RTG and automated RMG crane systems in most https://www.wendangku.net/doc/9211255536.html,ually,RTG yard blocks are arranged in terms of several yard blocks parallel to the quay wall,whereas automated RMG yard blocks are laid out perpendic-ular to the quay wall to ensure a clear separation of automated and manual operations. In most cases,an automated RMG crane system is embedded into a more or less automated container terminal that uses semi-automatic QCs and AGVs.For reasons of occupational safety,AGVs as well as SCs cannot be operated together with XTs. Consequently,waterside and landside transport machines have to be separated,which can be best facilitated by the perpendicular layout.
Furthermore,the handshake between the RTG cranes and other modes of transpor-tation usually takes place parallel to the yard block in an empty lane inside the portal, which is the handling lane,while the RMG cranes use the waterside and landside ends of the yard blocks for container handover.Within the RTG system,XTs or TTUs drive into the handling lane and stop at the bay where a container has to be transferred.Thus, there does not need to be laden driving for the RTG cranes,only empty movement to the relevant bay.In contrast,RMG cranes have to traverse laden as they transfer the container between the relevant bay and the handover area.
The main technical data for both crane types are dependent on the dimensions of the yard block,i.e.,the more lanes and the higher the stacking height,the wider and higher,respectively,is the portal.In addition,the maximum velocity and the accel-eration of the portal decrease with increasing crane size.Although the portal driving speed of the RMG crane is between3and4m/s,the RTG crane is slower with around 2m/s.The trolley and hoisting speed is around1m/s for both crane types,but again with slight advantages for the RMG cranes.A comparative table on technical gantry crane data is given in Stahlbock and V oss(2008).
Here,the automated RMG crane system is regarded.During the last years,sev-eral kinds of this crane system have been put into operations that can mainly be distinguished according to the number of applied cranes per yard block,as well as the crossing ability of these cranes.These different types of automated RMG crane systems are described in the following section.
2.2Types of RMG crane systems and block layout
Four different types of automated RMG crane systems are identi?ed in this paper—namely the single(SRMG),twin(TRMG),double(DRMG),and triple crane system (TriRMG).All of them are exempli?ed with a top view of a container terminal in Fig.3.The single crane system is the oldest RMG crane system and was introduced
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Fig.3Top view of a container terminal showing four types of RMG crane systems
in Rotterdam,the Netherlands in the1990s(Saanen2008).There,each yard block is operated by only one automated RMG crane,which serves both,the landside and waterside handover areas.The major advantage of the single system is its comparably simple behaviour which simpli?es the crane scheduling problem.But the handling capacity of just one crane is rather small,so long waiting times for XTs and disturbed QC job sequences may be the result.
A consequent derivative of the single crane system is the twin system which uses two identical cranes per block.As the cranes have the same size and share tracks,cross-ing of cranes within the same block is impossible.Consequently,one crane serves the waterside handover area and the other one the landside handover area.On the one hand, it is bene?cial that the system offers more handling capacity than the single system does,but on the other hand,it is more complex to operate,since crane interferences have to be regarded.In addition,the system is very vulnerable to machine breakdowns, since crossing of the cranes is not possible and thus a defective crane would jam the whole yard block.A twin system is for example in operation in Portsmouth,Virginia (Edmonson2007).
A comparable handling capacity along with a higher degree of?exibility can be reached by the double crane system,which also uses two cranes per block,but allows for crossing.This can be facilitated by using two cranes of different size,which do not share tracks,but have their own pair of rails each.Crossing is only possible if the trolley of the bigger crane is moved to a special crossing position which is located at the side of the big crane,beyond the pro?le of the small crane.This crossing position is illustrated in Fig.2.Hence,waterside and landside handover areas can be served by both cranes and such a system is in operation in Hamburg,Germany(Saanen2008).
Effects of storage block layout and automated yard crane systems569 The bene?ts of the crossing possibility are reduced(but nevertheless existing)crane interferences and reduced consequences of machine breakdowns.The downside of this possibility is that due to the second track per block,more space is needed and thus fewer blocks can be installed in a given yard area.
The latest development of automated RMG systems is the triple crane system.It has recently been put into operation in Hamburg,Germany(HHLA2009).Three cranes will be used per block:two small identical cranes sharing the same tracks and one bigger crane with its own rails.While—comparable to a twin system—the two small cranes cannot cross each other,the bigger one can cross both small ones,which is comparable to a double system.On the one hand,deploying three cranes per block further increases the handling capacity.On the other hand,more crane interferences have to be regarded for the scheduling problem,which makes crane control even more complicated than for the twin and double crane systems.
The dimensions of yard blocks differ between terminals,but typically the order of magnitude for automated RMG yard blocks is28–48bays(of TEU)long,6–10lanes wide and2–6tiers high.While the SRMG in Rotterdam,for instance,uses blocks which are28bays long,6lanes wide and2tiers high,the yard blocks of the DRMG in Hamburg,consist of37bays,10lanes and4tiers(Saanen and Valkengoed2005). However,these are just examples and various other layouts can be found at container terminals around the world.In total,the number of possible yard block layouts is huge,and four types of automated RMG crane systems are identi?ed that can be used for each layout.Consequently,terminal planners and researchers are faced with the question of which combination of yard block layout and yard crane system is best for the performance of the storage yard and the whole terminal.In the next section, the term performance is discussed in detail,since terminal and storage yard design planning are multi-objective problems with several interdependencies.
2.3Terminal and yard performance
Terminal operators are simultaneously faced with several restrictions and objectives of the different stakeholders.Hence,there are many indicators for measuring the performance of a seaport container terminal:workers want security of employment, residents demand low noise and exhaust emissions,authorities require the compliance with laws,truckers are interested in short processing times,and shipping lines require short and reliable turn-around times for vessels as well as little cost for loading and dis-charging.However,the?nal decision makers are the owners(shareholders)which are generally interested in a high shareholder value.From their point of view,the shipping lines are the most important stakeholders,since the earnings of a container terminal are most of all dependent on the handling charge that is raised from the shipping lines for each container handled by the QCs.High profits and rentability can be achieved by increasing the throughput of the terminal and decreasing its costs,with respect to the turn-around times of the vessels and limitations in space.Consequently,vessels have to be processed more quickly with the same amount of equipment,i.e.the GCR has to be increased.As the improvement of the GCR does also comply with the objectives
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At?rst glance,the GCR is only a measure for the performance of the QCs.How-ever,the GCR is also a measure for the performance of the whole terminal,since the QCs are just one end of the terminal’s transport chain that affects the GCR as a whole. In fact,the QC performance is considerably affected by the horizontal transport and yard processes.The QCs can only load and discharge containers when the in?ow and out?ow of containers is properly processed by the horizontal transport machines,i.e. the QC operations should not be disturbed due to late arrivals of AGVs or SCs.The horizontal transport operations are affected by the yard cranes,as they can only work properly if they need not wait at the yard blocks.Export containers,as well as outgo-ing transshipment containers have to be accurately retrieved by the yard cranes,since otherwise the horizontal transport machines have to wait.The situation for import boxes and ingoing transshipment containers needs to be distinguished,since AGVs are not able to discharge themselves while SCs can do this.Consequently,SCs that are laden with import or transshipment boxes need not wait for late yard cranes,while import operations of AGVs may be disturbed by delays of the yard cranes.Altogether, the joint performance of QCs,horizontal transport machines and yard cranes can be subsumed under a single performance indicator—the GCR.
The great impact of the yard operations for the performance of the whole termi-nal is con?rmed by the simulation analysis of Petering et al.(2009)on deployment strategies for RTG cranes.They?nd a very strong negative correlation of AGV and SC waiting time at the yard block with the GCR.Hence,they conclude that the main objective for yard crane dispatching should be the minimization of waiting times for the waterside horizontal transport machines.The waiting times at the yard blocks for XTs are usually regarded as matter of minor importance since hardly any impact on the GCR is involved with XT waiting times,and individual truckers are?nancially less important for the terminal than shipping lines(Choe et al.2007).Altogether,it is also possible to focus on the waiting time of waterside horizontal transport machines at the yard blocks when planning and optimizing automated RMG crane systems,instead of only looking at the GCR.Subsequently,the term yard block performance is used as an equivalent for the average waiting time per job of waterside horizontal transport machines in the handover area.
2.4RMG crane processes
Each ingoing and outgoing box at a container terminal induces a transport job for the automated RMG cranes.Besides,the pure yard crane transport of the container from its start position to its place of destination,several other crane movements are involved with a transport job.Certain sequences of these crane movements form different yard crane processes.Depending on the start position of a transport job,its place of desti-nation as well as its purpose,the following six types of yard crane processes can be distinguished:
Waterside storage:The crane performs an empty movement to the waterside hand-over area,picks up the container,performs a laden movement to
Effects of storage block layout and automated yard crane systems571 the dedicated stacking position in the block,and drops off the
container.
Landside storage:The crane performs an empty movement to the landside handover area,picks up the container from an XT,performs a laden move-
ment to the dedicated stacking position in the block,and drops off
the container.
Waterside retrieval:A container stored in the block has to be loaded onto a vessel.
The crane performs an empty movement to the current stacking
position of the container,picks up the container,performs a laden
movement to the waterside handover area,and drops off the con-
tainer.
Landside retrieval:A container stored in the block is called by an XT.The crane per-forms an empty movement to the current stacking position of the
container,picks up the container,performs a laden movement to
the landside handover area,and places the container on the XT. Shuf?e:If a container is stacked on top of a container that is to be retrieved,
a shuf?e move is required.All containers stacked upon the needed
one have to be moved to other slots before the needed container
can be retrieved.The crane performs an empty movement to the
current stacking position of the container,picks up the container,
performs a laden movement to the new stacking position,and
drops off the container.
Housekeeping:These crane movements are similar to shuf?e jobs.However,this type of move is done to improve the storage location of contain-
ers in the block.During high-workload situations,containers are
stored close to the ingoing handover point to reduce travel times.
As most containers will be retrieved at the opposite handover
points(depending on the fraction of transshipment containers),
these containers can be relocated to a slot near the other hand-
over point during situations of low workload.By this strategy,the
usage rate of the cranes can be smoothed.
Waterside and landside storage and retrieval processes can be regarded as the main processes of automated RMG cranes,while shuf?e and housekeeping jobs are only assisting processes.Shuf?e processes should be avoided if possible because they are unproductive,i.e.they absorb valuable crane resources as they are not directly related to storage or retrieval requests.
3Literature overview
In total,more than300references on container terminal issues are available and this number is steadily growing,but the design problem of RMG crane systems is hardly addressed in the literature.In this section,a brief overview on literature relevant to this study is given,which comprises papers on container terminals that discuss terminal design,RMG crane control,and simulation modeling.Extensive surveys on container
572N.Kemme terminal literature are given by Stahlbock and V oss(2008),Steenken et al.(2004),and Vis and de Koster(2003).
Thirteen references on strategical design of container terminals can be found in the literature,whereof nine address performance comparisons of different types of termi-nal equipment and four investigate effects of the layout decisions.While Duinkerken et al.(2006)and Yang et al.(2004)compare different options for the horizontal trans-port of containers,different types of stacking operations are regarded by Chu and Huang(2005),Valkengoed(2004),and Saanen and Valkengoed(2005).Moreover, Saanen et al.(2003),Vis(2006),Liu et al.(2002),as well as Nam and Ha(2001) evaluate different combinations of horizontal transport and storage yard equipment. The layout planning problem is addressed by Liu et al.(2004),Kim et al.(2008), Petering and Murty(2009),and Petering(2009).In the last two articles,the effects of the length and the width of the yard blocks for a gantry crane operated container yard are evaluated.However,instead of an automated RMG crane system—as regarded here—RTG operated yard blocks are investigated.A joint analysis on the effects of the yard block layout and the applied RMG crane system has not yet been found in the literature by the author.In addition,to the author’s knowledge,the TriRMG has not yet been regarded in any terminal design study.
In contrast to operational planning problems for RTG cranes,the control of auto-mated RMG cranes has not yet been widely studied.In total,11papers that are relevant for the stacking and crane deployment problems of RMG crane systems can be found, but only7articles are applicable for automated RMG crane systems like those regarded here.Dekker et al.(2006),Steenken et al.(2004),and Chen(1999)address the con-tainer stacking problem.Although the last two papers give an overview on generally applicable stacking strategies,only the?rst one investigates the stacking problem for an automated RMG crane system.The crane deployment problem is investigated by eight papers in total,whereof only six papers are directly applicable to the yard crane system regarded here.Cao et al.(2008)and Bohrer(2005)present MIP models for RMG crane systems,where the handover to other modes of transportation takes place parallel to the yard block.Thus,they are more applicable to RTG crane systems.While Vis(2002)and Choe et al.(2007)consider crane deployment strategies for SRMG and TRMG respectively,Zyngiridis(2005)present IP models for both SRMG and TRMG. Stahlbock and V oss(2010)as well as Vis and Carlo(2010)investigate crane deploy-ment strategies for DRMG,whereas the crane scheduling problem for the innovative TriRMG is?rst regarded by Dorndorf and Schneider(2010).
Hosts of simulation studies and papers addressing simulation topics are identi?ed in the literature on container terminals.A selected overview on the most recent papers is given in Petering et al.(2009).The focus of these articles ranges from studies on operational(e.g.Briskorn et al.2006)and strategical planning problems(e.g.Saanen et al.2003)to the generation of container terminal scenarios as input for simulation models(e.g.Hartmann2004).The presented simulation models vary in the level of detail,the used programming language,the modelled object(s),the visualization,the purpose,and various other criteria.According to Petering et al.(2009),the major lim-itations of most simulation models on container terminals are the restriction to only one vessel at the same time and rather short simulation horizons,often of only one day.
Effects of storage block layout and automated yard crane systems573 Altogether,several papers can be found,but no study that investigates the joint effects of different automated RMG crane systems and yard block layouts for the long-run performance of a multiple-berth container terminal.In the following section, a simulation model is presented that is appropriate for such a simulation study.
4Simulation model of an automated container yard block
Simulation is a useful technique for problems that cannot be adequately solved by an analytic model or for problems whose analytical solution can only be obtained by making so many simplifying assumptions that the solutions are not applicable to the original problem.This is the case for real-world problems with high degrees of com-plexity,dynamics,and stochastic relations.In container terminal operations,a lot of stochasticity is involved:XT arrivals are completely unpredictable,the arrival times of vessels are also uncertain to some degree,and the duration of terminal operations is dependent on many human-in?uenced factors.In addition,container terminals are complex facilities with several types and numbers of equipment in several dozens of possible states that can be located in a large number of yard locations.As a con-sequence,simulation is the method of choice to investigate the stochastic real-time operations of an automated RMG container yard.
In this section,a discrete event simulation model is presented,that is able to repro-duce the multi-objective,stochastic,real-time environment of an RMG yard block at a multiple-berth facility over a user-de?ned period of time.The model has been imple-mented and validated with numerous pilot runs based on the author’s work experience at several container terminals and on discussions with managers and staff members at these terminals.Owing to limitations in space,only the conceptual design of this simulation model and its main features and limitations are explained in this section.
A complete description of the applied simulation model—including all its function-alities,events,inputs and outputs,as well as details on the implementation of all simulation processes and stochastic distributions—is provided in Kemme(2010). 4.1Conceptual design
The simulation model is designed to reproduce a freely scalable container yard block along with the corresponding waterside and landside handover areas and the selected RMG crane system.The number of bays,lanes,and tiers as well as the capacities of the handover area are freely scalable and SRMG,TRMG,DRMG,and TriRMG can be selected as operating crane system for the yard block.All crane processes that are explained in Sect.2.4are explicitly considered in the model.The length of the simulation runs is a user-de?ned parameter,therefore,it is a nonterminating type of simulation(Law and Kelton2000).To obtain a sound comparison of different RMG crane systems and yard block layouts,seed initialized stochastic distributions are used. Thus,identical random numbers can be used in simulating different systems and simu-lation results are reproducible by applying identical parameter settings.The simulation model is implemented in Tecnomatix Plant Simulation8.2.
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Fig.4Architecture of simulation model
The simulation model comprises hundreds of variables,parameters,tables,meth-ods,dialogs,and other objects—each of them connected with a certain system of the simulation model.In total,six systems and several subsystems can be distinguished. An overview of the architecture of the implemented simulation model and the inter-actions between the systems is given in Fig.4.
The main systems of the simulation model are depicted in the middle of Fig.4. The scenario-creation system comprises all functions concerning the generation of reproducible container arrivals and departures for the modelled yard block.While individual containers as well as vessel and truck arrivals are randomly generated by a parameter-based data generator,the time of container arrivals and departures at the modelled block are determined by a data preprocessing subsystem which imitates the operations of QCs and WS horizontal transport machines in a simpli?ed way.
The administration system and the drive-control system are the core of the simula-tion model.While the latter one executes and controls all crane movements,the admin-istration system has many functions.First,the storage block capacities are managed. Secondly,the job-management subsystem generates and manages transport jobs for the gantry cranes,initiates their scheduling,and initiates the execution in the sched-uled order.Thirdly,the handover-area management controls the occupancy of the handover-area capacities.
The strategy system is closely linked with the administration and drive-control sys-tems as it contains exchangeable decision procedures for theses systems.The stacking subsystem decides on stacking locations for containers and returns its decision to the storage-management subsystem.The crane-deployment subsystem schedules the crane assignment and sequencing of transport jobs and returns the schedule to the job-management subsystem.For crane systems with crossing ability the crane-crossing
Effects of storage block layout and automated yard crane systems575 subsystem decides on the execution of a crossing process and returns the decision to the collision-and deadlock-avoidance subsystem.
The experimental-control and the statistics system have assisting cross-sectional functions for the main systems.By means of the experimental-control system differ-ent experiments can be automatically conducted by the simulation model.Statistical data are continuously gathered and processed by the statistics system.
4.2Main features
The model has several noteworthy features that are subsequently explained.First of all, there is a parameter-based data-generation program that is in some components based on the data generator proposed by Hartmann(2004).The generation program produces individual transport modes(feeder vessel,deep-sea vessel,XTs)and containers.The number of container arrivals at the modelled yard block—i.e.its workload—is speci-?ed by the user-de?ned planned average?lling rate of the block and its capacity.Hence, the workload is always adjusted to its capacity,leading to comparable results for dif-ferent yard block layouts.For each individual vessel,the arrival times,the lengths, and the number of containers to be loaded and unloaded are randomly chosen—with respect to the user-de?ned length of the quay wall—according to distributions which can be speci?ed by the user.While the arrivals of deep-sea vessels are mainly deter-mined by a user-de?ned,weekly repeated vessel call pattern and only the exact arrival times vary by a few hours from week to week,the arrival times of XTs and feeder vessels are generated completely at random and there is no weekly repetition.The randomly generated attributes for each container comprise information on the ingoing and outgoing mode of transportation,the size,the weight,and the port of destination. Since the program provides data generation for variable fractions of transshipment containers,pure transshipment terminals,import-export terminals,and hybrid termi-nals can be simulated.In addition,the dwell time of each container is randomly drawn based on an exponential distribution with user-speci?ed parameters.In summary,the data generator produces individual transport modes and containers and assigns each container to a transport mode for delivery and pick-up in a way such that the prede?ned distributions on transport modes,transport mode sizes,transport mode arrival times, and dwell times are matched simultaneously.
Besides the data generation program,the simulation naturally contains some sto-chastic components:?rst,the time between the announcement that an AGV/SC or XT is due to arrive and its actual arrival at the handover area—which is the look-ahead horizon—is a random triangular-distributed variable.Since the waterside transport is controlled by the terminal,it would be sensible to expect a longer look-ahead horizon for waterside arrivals than for landside arrivals.Therefore,different parameters for the distributions of both handover areas can be speci?ed.Secondly,the time required for?ne positioning and twist-lock-handling of the spreader at the pick-up and drop locations is a random gamma-distributed variable.Different parameters can be de?ned for?ne positioning in the yard block and in the waterside and landside handover areas.
Even though the?ne positioning of the spreader is a stochastic component,all crane movements—including portal,trolley and spreader movements—are realistically
576N.Kemme mapped.For all three crane components,the exact location in time is always cap-tured and acceleration and deceleration are taken into consideration in terms of time and distance.In addition,different values for velocity,acceleration and deceleration can be set for portal,trolley and spreader of each crane depending on whether the crane is laden or not.Furthermore,for the waterside horizontal transport,the user can choose between SCs and AGVs which has notable effects on the performance of the crane system(cf.Sect.2.3).To avoid collisions and deadlocks for TRMG,DRMG, and TriRMG,a collision-avoidance mechanism is implemented,which ensures that a crane is only allowed to enter a zone of the yard block if the relevant zone has previ-ously been claimed by that crane.Furthermore,the mechanism controls the crossing processes of the cranes within the DRMG and TriRMG systems.
Altogether,an impression of the level of detail and the extensive con?guration pos-sibilities of the simulation program is given by the following?gures:?rst,depending on the selected crane system,between100and200parameters can be speci?ed per simulation run.Secondly,during each simulation run,60–220statistical?gures are collected and computed.
4.3Assumptions and limitations
First of all,the most important limitation is that QCs and waterside horizontal trans-port machines are not explicitly modelled.It is assumed that the related processes are deterministic and that a suf?cient number of transport equipment is always available, so that no waiting times for the RMG cranes are induced due to late arrivals of AGVs or SCs.In addition,only one yard block is modelled.Therefore,the interdependencies between processes of the whole storage yard,the SCs/AGVs and QCs are neglected here and the GCR cannot be used as a performance indicator.However,in Sect.2.3it is qualitatively discussed that the waiting times of SCs/AGVs at the waterside handover areas have significant effects for the GCR.
Furthermore,trains and land–land movements are ignored within the model.The former assumption can be made without loss of generality since the transport between a rail yard and the landside handover areas of the yard block would be performed by TTUs.Hence,the processes are similar to that for XTs,only the look-ahead hori-zon for arrivals of TTUs may be longer since the transport is controlled by the terminal. In addition,no noteworthy limitation is involved with the latter assumption,since con-tainers arriving and departing by XT are usually not desired by the terminals and only make up for very small fractions of the overall cargo volume.
Only20 and40 standard dry containers are considered.Containers of other sizes (45 long,foldable,etc.)and boxes for special goods(refrigerated goods,liquids, dangerous goods,etc.),which are accountable for about15%of the throughput of a container terminal(Petering et al.2009),are neglected.For the twin and triple crane systems,it is assumed that the small crane which is located closer to the waterside only serves the waterside handover area and never the landside handover area,while the same applies vice versa for the landside crane.In addition,technical errors and machine breakdowns are ignored for the RMG cranes.
Effects of storage block layout and automated yard crane systems577 5Simulation analysis
Based on the simulation model that is described in Sect.4,a simulation study is con-ducted.The purpose of this study is to analyse and to identify the joint effects of different yard block layouts and RMG crane systems on the performance of a single yard block.Subsequently,the experimental design and the parameter settings of the simulation study are shortly described.Thereafter,the results are summarized and the most important?ndings are explained and discussed.
5.1Experimental design
For the purpose of this simulation study,385different layouts are regarded.Each of these layouts is tested with each of the four crane systems introduced in Sect.2.2. The number of layouts results from all possible combinations of11different block lengths,7different block widths,and5different stacking heights.In detail,the num-ber of bays is varied in the interval from28to48in steps of two bays,the number of lanes is changed from6to12and the number of tiers is varied in the interval from2to 6.In total,1,540experiments—i.e.,combinations of layout and crane systems—are conducted.
In this study,the replication/deletion approach is applied for estimating the steady-state mean of the yard block performance.Hence,the simulation results are based on multiple simulation runs which only use observations beyond the warm-up period for estimating the steady-state mean(Law and Kelton2000).Based on the application of the graphical procedure of Welch(1981)to several pilot runs,the length of the warm-up period is set to14days.By means of further pilot runs,the length of the simulation runs and the number of independent replications are determined.It is found that no significant gain in the reliability of the simulation results is involved with very long simulation runs and exhaustive numbers of replications,as the steady-state mean of the yard block performance remains nearly unchanged and the corresponding con?dence intervals do not improve either.Here,as a tradeoff between additional reliability and the simulation cost in terms of CPU runtime,the simulation length is set to42days and10independent replications with different seed-initialized random numbers are conducted for each of the1,540experiments.
The experiments are carried out in the Windows XP environment on a2.2GHz Pentium Dual Core2machine with4GB of RAM.The CPU runtime for each exper-iment varies between5and90min depending on the crane system and the size of the yard block.
5.2Experimental parameter settings
A detailed listing of all parameter settings is provided in Kemme(2010).Here only the most important parameter settings are given,because the huge number of possi-ble parameterisations.The values of the parameters are based on the author’s work experience and are mostly con?rmed by several independent reports(Hartmann2004; Saanen and Valkengoed2005;Stahlbock and V oss2008).
578N.Kemme
Fig.5Weekly repeated vessel call pattern for the terminal under consideration
The modelled yard block is embedded into a terminal with a yearly throughput of2 million TEU and a quay wall of1,400m length.Its weekly repeated vessel call pattern is depicted in Fig.5.Nine deep-sea vessels arrive a week,whereof four vessels are of type1(1–4)and?ve vessels are of type2(5–9).While vessels of type1randomly make between2,400and3,600moves per call,need380m berth length,and have a maximum berthing window of26h each,vessels of type2make between1,000and 2,200moves per call,need340m berth length,and have a maximum berthing window of16h each.Of course,the exact arrival times and berthing windows of individual vessels randomly vary from week to week and depend on the random number of moves per call for the relevant vessel.To minimize driving times for the SCs,that are selected as the transport machines between the QCs and the yard blocks,it is assumed that only vessels of the?rst half of the quay are connected with the modelled yard block.Hence, only proportional fractions of containers that arrive or depart by vessels1,3,5,7,and 9are stored in the block being analyzed.Note,the remaining quay wall capacity is partly needed for randomly generated arrivals of feeder vessels.
The mean container dwell time is set to5days with a minimum dwell time of 24h and the fraction of transshipment containers that are handled by the QCs is set to30%.The fraction of40 containers is set to60%.Furthermore,container arrivals are generated that yield an average block?ll rate of75%and a maximum?ll rate of 80%is allowed.The look-ahead horizon for an arrival at the waterside and landside handover points of the yard block is a triangularly distributed random variable with parameters(a=3.0,b=5.0,c=22.0)min and(0.0,1.0,2.0)min,respectively.
A stacking position of a container in the yard block is determined in real-time by the category stacking strategy(Dekker et al.2006)which reduces the number of required shuf?e moves.Hence,only export containers of the same category—i.e.,having the same size,weight group,port of destination,and loading vessel—that are destined for a deep-sea vessel are stacked in the same pile.For import containers as well as boxes
Effects of storage block layout and automated yard crane systems579 that are destined for feeder vessels,the category stacking strategy is not applicable since only insuf?cient information about its anticipated departure time is available.
A detailed investigation of different crane deployment strategies is outside the focus of this study.Thus,like other strategical simulation studies on RMG crane systems do(Valkengoed2004;Saanen and Valkengoed2005),a simple priority rule is applied here.Of course,better performance results may be obtained by applying more elab-orate crane deployment strategies,but the application of these strategies is usually restricted to a certain type of RMG crane system(cf.Sect.3).Therefore,these crane deployment strategies are inappropriate for this study,as identifying the pure perfor-mance effects would be complicated by applying different strategies for the different RMG crane systems.In contrast,priority rules are easily applicable to different types of gantry-crane systems.In this study,the earliest due date priority rule is applied to all four types of RMG crane systems,i.e.,an idle crane is assigned to the job with the smallest due date which de?nes the time when the corresponding container has to be picked up by the crane to avoid waiting times in the handover areas for SCs and XTs. Ties are broken by the smallest empty driving time and—unlike for real-world applica-tions—waterside jobs are not prioritized in any way.In addition,housekeeping moves are neglected in this study.
The maximum speed of the crane portal is set to4m/s for the small crane and to 3.5m/s for the big crane.Acceleration as well as deceleration of both portals are set to 0.8and1.0m/s2for laden and unladen driving,respectively.For all trolleys,the max-imum speed is assumed to be1m/s,independently of whether they are laden or not. The maximum lifting speed of the spreader is0.8m/s,if laden and1.0m/s if empty. Acceleration and deceleration of all trolleys and spreaders are set to0.4and0.5m/s2for laden and empty movement,respectively.The gamma-distributed time in seconds for?ne positioning of the spreader is parametrized with(μ=10.0,σ2=20.0)s for the waterside handover area,(40.0,400.0)s for the landside handover area,and (6.0,7.2)s for inside the yard block.
5.3Results and?ndings for the yard block layout
First of all,it has to be noted that not all numerical results of the1,540experiments can be given here,due to limitations in space.Instead,the overall?ndings are exem-pli?ed in Table1,with simulation results in terms of selected performance?gures for combinations of all four crane systems and nine representative yard block layouts. The layouts are chosen with the aim to separately illustrate the performance effects of the length,the width,the height and the stacking capacity of an RMG yard block. Therefore,three different numbers of bays(28,36,44),lanes(6,8,10),and tiers (2,4,6)—representing small,medium,and large values of the corresponding block dimensions—are combined to nine different layouts in a way such that three layouts are available for exemplifying the effects of each the block length,width,height,and capacity(e.g.the performance effects of the block length are exempli?ed by the lay-outs‘short’,‘medium’,and‘long’).The mean waiting time of XTs and SCs for all types of jobs at both sides of the block is shown in the‘μtotal’column.In the‘μwsout’,‘95%CI ofμwsout’,‘σwsout’,and‘max wsout’columns the mean,the95%con?dence
580N.Kemme Table1Mean waiting time?gures of10simulation runs for selected cases(s)
Layout RMGμtotalμwsout95%CI ofσwsout max wsout systemμwsout
Small SRMG27.96 4.38(3.06;5.64)39.90558.96 28×6×2TRMG8.94 2.52(1.32;3.72)28.92509.04 DRMG13.92 2.34(1.56;3.12)26.58457.92
TriRMG8.70 3.00(2.40;3.60)34.08555.84 Medium SRMG270.48471.48(436.62;506.34)656.944,021.08 36×8×4TRMG55.2649.74(43.02;56.46)136.261,174.32 DRMG75.3653.22(50.04;56.40)142.021,066.32
TriRMG40.1423.94(21.06;26.82)92.401,107.18 Big SRMG5,019.069,987.96(9,725.58;10,253.58)5,992.8640,390.62 44×10×6TRMG1,966.984,310.34(4,100.22;4,520.46)3,281.1017,455.38 DRMG2,388.544,892.28(4,716.06;5,068.50)3,810.1222,917.60
TriRMG1,010.522,144.82(2,012.64;2,277.00)2,176.4412,055.08 Short SRMG116.82136.02(121.80;150.24)261.661,771.80 28×8×4TRMG37.6822.26(20.10;24.42)81.84817.20 DRMG56.3426.58(24.66;28.50)95.341,056.78
TriRMG31.9815.12(12.66;17.58)72.72937.44 Long SRMG913.081,833.84(1,703.52;1,964.16)1,834.5611,443.80 44×8×4TRMG86.10107.52(94.38;120.66)229.561,676.34 DRMG110.76114.66(105.18;124.14)230.161,567.86
TriRMG49.3232.28(29.10;35.46)103.681,011.12 Narrow SRMG137.94177.96(159.54;196.38)315.481,851.9 36×6×4TRMG42.9030.12(27.96;32.28)99.18889.98 DRMG57.5433.12(30.42;35.82)112.201,002.66
TriRMG31.0814.22(12.78;15.66)68.58870.90 Broad SRMG709.741,425.54(1,277.46;1,573.62)1,605.309,773.40 36×10×4TRMG75.7287.18(79.08;95.28)192.481,423.20 DRMG109.62111.84(100.92;122.76)226.381,528.08
TriRMG49.6833.96(30.90;37.02)108.181,018.50 Low SRMG42.9010.50(8.58;12.42)63.96828.66 36×8×2TRMG13.50 4.86(3.66;6.06)40.50663.66 DRMG24.00 6.90(6.00;7.80)54.90760.38
TriRMG12.36 5.16(4.14;6.18)44.58681.60 High SRMG2,615.165593.68(5,486.40;5,700.96)3,967.3227,269.76 36×8×6TRMG427.74899.04(843.96;954.12)1,040.465,730.60 DRMG567.421,098.78(1,023.54;1,174.02)1,289.467,313.82
TriRMG178.68302.34(270.60;334.08)463.143,203.52μtotal Mean waiting time of XTs and SCs for all jobs,μwsout mean SC waiting time for waterside retrieval jobs,95%CI ofμwsout95%con?dence interval of mean SC waiting time,σwsout standard deviation of SC waiting times for a waterside retrieval job,max wsout maximum SC waiting time for waterside retrieval jobs
Effects of storage block layout and automated yard crane systems581
Fig.6System-dependent performance effects of the yard block capacity for1,540experiments interval of the mean for ten replications,the standard deviation,and the maximum of
SC waiting times for waterside retrieval jobs are given,respectively.Subsequently,
the simulation results are mainly investigated forμwsout which is probably the most
important performance?gure of a yard block(cf.Sect.2.3).In addition,it can be seen
from Table1that most changes ofμtotal,‘95%CI ofμwsout’,σwsout,and max wsout are
in line withμwsout.
The storage capacity of a yard block—which is given by the corresponding block
layout—directly de?nes its workload situation(cf.Sect.4.2).The effects of different
yard block capacities and RMG crane systems for the yard block performance are
depicted in Fig.6.The capacity is noted on the abscissa and the performance—mea-
sured as mean value ofμwsout—is shown on the ordinate.At?rst glance,the results
seem to be as anticipated.With increasing capacity,μwsout is also increasing for all
crane systems since more jobs have to be handled by the cranes.For most capacities,μwsout is by far the greatest for SRMG and the smallest for TriRMG.The perfor-mances of DRMG and TRMG are comparable and somewhere in between SRMG
and TriRMG.For layouts with rather small capacities,the SC waiting times are nearly
comparable,while for larger yard blocks,significant performance differences between
the crane systems are observed.While,for example,the meanμwsout of SRMG and
TriRMG only differ a few seconds in the‘small’layout and the95%significance inter-
vals are even overlapping,a significant difference of more than two hours is observed
for the‘big’layout.
Inspection of Fig.6suggests a functional relation between the yard block capacity
and its performance.To?nd out the function type that best explains the yard block
performance by its capacity,separate curve-?tting analyses are conducted for all four
582N.Kemme crane systems on the basis of the corresponding3,850individual observations ofμwsout that are available for each crane system.The resulting coef?cients of determination (R2)reveal that the spread of mean SC waiting times can largely be explained by
quadratic(0.822–0.936)and cubic(0.932–0.936)regression functions,as well as by generalised(power)functions(0.840–0.891)with the regression parameters being the exponents.Even a linear regression yields acceptable R2in the range from0.587to 0.868.
However,the original objective of this simulation study is not the analysis of the effects of the yard block capacity.Moreover,the performance effects of the capacity determining factors of block length,width,and height have to be quanti?ed.Indeed, a more detailed look at the results reveals that more SC waiting time is induced by the number of tiers than by the number of bays and lanes.For layouts with the same capacity,it can for instance be observed that about50%longer SC waiting times are caused by each additional tier.
To quantify the performance effects of all three yard block dimensions,once again separate regression analyses are carried out for all four crane systems based on the cor-responding3,850individual observations ofμwsout.For this purpose,a new regression model is developed that has to ful?ll three important properties:?rst,the previously found explanation of the performance spread by different functions of the yard block capacity should be utilized in some way.Secondly,b,l,and t—which are the number of bays,lanes,and tiers,respectively—should explicitly be considered in the model to grasp their performance effects.Thirdly,the model should be easily interpretable and amenable to statistical significance testing of the model itself as well as its parameters. All these properties are ful?lled by the multiplicative regression model
μwsout=a·bγ1·lγ2·tγ3(1)
that can be used to estimate the mean SC waiting time(s)at the waterside block ends for certain layouts.The?rst and second property are simultaneously ful?lled by replacing the capacity by its product b·l·t in a function type that previously yielded promising coef?cients of determination—the power function.As a consequence,b,l,and t are explicitly built in and their individual performance in?uences are then grasped by γ1,γ2,andγ3as exponential parameters for b,l,and t,respectively.The greater one of this parameter values is compared with the other ones,the more SC waiting time is induced by the corresponding block dimension for the type of RMG system being examined.Finally,property three is ful?lled as well,since the non-linear function1 can be linearised by means of the(natural)logarithm.The testing of this linearised model for statistical significance is then straight forward.
For two reasons,the regression analyses are performed for one data set including all15,400simulation runs and one data set which only includes the runs yielding μwsout≤600s.First,SC waiting times longer than600s may indicate that the cor-responding combination of crane system and layout does not have any relevance for real-life applications(cf.Sect.5.5).Secondly,the regression analyses for relevant experiments should not be biased by very long waiting times of experiments with large capacities.
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(完整版)高中数学新课标学习心得体会
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初中生物第三单元(生物圈中的绿色植物)知识点
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第三专题 生物圈中的绿色植物 一、绿色植物与生物圈的水循环 [知识网络结构] 水就是植物体的重要组成成分 原因 水保持植物直立的姿态,有利于进行光合作用 1、绿色植物的生活需要水 无机盐只有溶解在水中,才能被吸收与运输 水影响植物的分布:降水量大的地方,植被茂密 根吸水的部位:主要就是根尖成熟区, 吸水 成熟区的特点:生有大量根毛,增大根吸水的表面积 2、水分进入植物体内的途径 途径:木质部的导管 水分的运输 方向:自下而上 树皮:韧皮部中有筛管,输导有机物 茎的结构 形成层:细胞能分裂(木本植物有此结构) 木质部:有导管,输导水分与无机盐 实验:观察叶片的结构(练习徒手切片) 表皮(上、下表皮) 叶片的结构 叶肉 叶脉 重要结构:气孔,就是植物蒸腾失水的门户,也就是气体交换的窗口,由成对的保卫细 胞围成,气孔的开闭由保卫细胞控制。当保卫细胞吸水膨胀时,气孔张开, 当保卫细胞失水收缩时,气孔关闭。 概念:水分以气态从植物体内散发到体外的过程。 蒸腾作用 主要部位:叶片 降低了叶表面的温度 意义 促进对水与无机盐的运输 促进对水的吸收 绿色植物促进了生物圈中的水循环 绿色植物参与生物圈的水循环 提高大气湿度,增加降水量 保持水土 [课标考点解读] 绿色植物促进了生物圈中的水循环,因此保护森林与植被有非常重要的意义。本章重点阐明水就是绿色 植物生存的必要条件,水对植被的影响,植物吸水的主要部位及特点,水运输的途径,蒸腾作用的意义。在能力培养方面,通过解读数据,培养学生的探究能力。 [典型例题剖析] 例1、把发蔫的菠菜泡在清水中,菠菜又重新挺起来,这说明( ) A 、水就是光合作用的原料 B 、水就是溶解与运输物质的溶剂 C 、水能保持植物体固有的姿态 D 、水就是植物体重要的组成成分 [解析]:植物体内只有水分充足时,才能保持挺立的姿态,叶片才能舒展,有利于光合作用。本题没有数据说明水就是植物体的重要组成成分,也没有说明水就是如何作为溶剂来溶解无机盐的。本题考察学生对植物需水原因的分析与理解。答案:C 例2、下图所示,植物吸收水分的主要部位就是( ) [解析]:根尖成熟区就是吸水的主要部位,表皮细胞突起,形成大量根毛,大大增加了吸水的面积。本题主要考察学生识图的能力。答案:A 例3、3月12日就是我国的全民植树节,之所以选择这个时候,就是因为( ) A 、正值农闲时节 B 、土壤松散 C 、雨水较多 D 、叶没长出,蒸腾作用很弱 3、绿色植物参与生物圈的水循环
生态环境绿色标杆企业创建方案
市生态环境绿色标杆企业创建 实施方案（试行） 为深入贯彻落实生态环境部《关于加强重污染天气应对夯实应急减排措施的指导意见》和《市打赢蓝天保卫战作战方案暨2018-2020年大气污染防治攻坚行动实施方案》，激励企业积极创建环保绿色标杆，主动减排，制定本方案。 一、总体要求 全面贯彻落实党的十九大精神和绿色发展理念，坚持“污染排放空间换时间”原则，鼓励企业切实承担污染治理主体责任，强化企业自我监管，积极落实各项减排措施。对达到绿色标杆标准的企业，在错峰生产和重污染天气应急（红色应急除外）期间，实行差别化管理，准予不停产、不限产，实现生产经营和污染减排的双赢。 二、实施范围 钢铁、焦化、炭素、陶瓷、玻璃、石灰窑、铸造、炼油与石油化工、制药、农药、涂料、油墨、工业锅炉、页岩砖、木业加工、表面涂装、家具、印刷（限书报刊、本册平板印刷、无VOCs排放的数字印刷）。（其他行业绿色标杆创建标准根据污染治理进程补充制定。） 三、创建要求 （一）基本要求 企业建设和运行有合法手续，上年度亩产效益评级为良好以上、 - 1 -
无重大环境投诉及群体性上访、未发生重大环境事故、没有被国家和省各类督察巡查发现问题并通报、无环境违法排污行为，按要求实现废气污染物排放在线监控，开展自行监测并实现信息公开，有完善的环保管理制度并有专职环保管理人员。 （二）行业创建标准 各行业创建标准见附件1。 四、豁免政策 对于列入错峰生产、重污染应急减排清单企业，达到绿色标杆企业创建标准要求的，在错峰生产、重污染应急（红色除外）期间免予停产、限产（国家和省明确规定必须执行停限产要求的除外）。 五、实施程序 采用企业自愿申报、县区审核、社会公示、市级核发的工作方式，开展生态环境绿色标杆企业认定工作。 （一）企业申报。按照企业自愿参与的原则，由企业向所在县区大气办提交绿色标杆企业申请表（见附件2，纸质版，A4纸打印并装订成册，一式三份）和电子版。 （二）县区审核。各县区大气办依据绿色标杆企业创建标准和豁免政策对申请表进行复核，筛选出符合条件、综合评价较高的绿色标杆企业。 （三）社会公示。对遴选出的绿色标杆企业，各县区大气办在官方网站和主流媒体进行公示，公示时间不少于5个工作日。对公示无异议的企业，报市大气办备案。 - 2 -
小学语文小班化教学案例
小学语文小班化教学案例 -----培养学生自主与合作学习能力的协调发展 一、案例背景 语文课程标准中指出：“倡导自主、合作、探究的学习方式”，由此可见，自主学习与合作探究的学习方式已成为课程改革的目标之一。那么，如何使自主学习与合作探究的学习方式在我们小班化课堂教学中有用地进行呢？通过自己的教学实践，我感到，教师要善于根据学生特点，为他们创设自主与合作学习的条件，才能确实使自主与合作学习落到实处，而不会是“看似课堂上热热闹闹，实则只是摆摆花架子而无实效性”的局面。下面，我就《我为你骄慢》一课的教学作了尝试。《我为你骄慢》是二年级下册一篇叙事性的文章，故事中的小男孩不小心打碎了老奶奶家的玻璃，当时害怕逃跑了，但后来用自己的行动取得老奶奶的原谅，老奶奶为小男孩感到骄慢。教学时，我给他们充分地自读自悟的机会，给他们个性化表达的机会，同时充分利用小班化小组学习的条件，进行组内合作学习，学会讨论、交流。 二、案例描述 1、解放读课文，要求读准字音、读通句子。 2、旁桌互认生字。 3、组长检查词语。 4、想想小男孩和老奶奶之间发生了什么事。根据下面的提示说一说：送报的小男孩，后来。老奶奶为小男孩感到。 （学生从自主学习到组内合作、交流，参与的主动性、积极性很高，学习气氛非常浓重。） 片段二：叙说故事情节； 1、默读课文1、2自然段，然后试着用自己的话向大家介绍“我打碎玻璃”的详尽经过。小组内练说，指名说。 2、引读第三自然段。
说话：我觉得很不自在，是因为。 生1：我觉得很不自在，是因为我打碎了老奶奶家的玻璃，难以为情见老奶奶。 生2：我觉得很不自在，是因为我担心老奶奶知道。 生3：我觉得很不自在，是因为我做了错事，老奶奶却还微笑着对我。 生4：我觉得很不自在，是因为我很后悔逃跑，感到良心不安。 3、默读四、五自然段，说说我是如何向老奶奶道歉的。 提供词语帮助说话： 三个星期过去了攒钱便条信封 xx悄悄地信箱松弛 小组内练说、指名说。 （通过叙说故事情节，让学生将课文的语言有用地迁移于自己的言语实践，这个要求对于中下层次的学生来说有难度，但是先让学生在小组内练习，让小组里会说的同学先说，能为中下层次的同学提供互助学习的机会，形成了一个优良的学习小环境。） 片段三：说话训练； 师：老奶奶为小男孩的什么而骄慢呢？ 生1：为他的厚道。 生2：为他的英勇。 师引导：这叫敢于承担责任。 生3：为他的知错就改。 师：当小男孩看到“我为你骄慢”的便条时是什么样的心情？
初中生物《生物圈中的绿色植物》单元教学设计以及思维导图
初中生物《生物圈中的绿色植物》单元教学设计以及思维导图1 《生物圈中的绿色植物》主题单元教学设计适用年级六年级 所需时间课内共用7课时，每周3课时 主题单元学习概述 本单元是山东科技出版社五四制，生物学六年级下册。本教材改变了以前教材过分强调学科体系完整性的状况，对分类学知识不再详细描述，降低了知识的难度，注重从学 生的生活经验出发，把提高学生的生物科学素养放在首位,重点是植物和生活环境相适应 的特征及在生物圈和人类的关系。 教材的知识编排结构是从生活环境、基本特征、在生物圈中的作用以及与人类的关系等几个方面进行讲述的，既可以对前面生物与环境相互影响的知识进一步巩固和深化， 又可以为后面学习绿色植物对生物圈的重大意义打下基础。本章节安排三节内容，“藻类、苔藓和蕨类植物和种子子植物，”这些植物放在一章内有利于学生对这三类植物的 特征进行横向的比较。 主题单元规划思维导图 主题单元学习目标 知识目标: (1)概述藻类、苔藓和蕨类植物的形态特征与生活环境。(2)了解藻类、苔藓和蕨类植物对生物圈的作用及与人类的关系。(3)知道种子的结构，明白玉米种子和菜豆种子的区别。(4)了解种子植物分为被子植物和裸子植物的依据并能够举例。能力目标: (1)通过对图片的观看、实物的观察，培养和训练观察能力和思维能力。 (2)通过讨论交流和展示，培养团队协作和归纳表达能力。情感态度与价值观: (1)关注生物圈中各种绿色植物及其生存状况，增强同学们的环保意识。 (2)通过展示交流，树立自信自强心。 对应课标:
1.初步具有收集、鉴别和利用课内外的图文资料及其他信息的能力。 2.关注绿色植物的生存状况，形成环保意识。 3.描述细胞分裂的基本过程。 4.描述各类植物的主要特征和生活环境。 5.说出植物在自然界的作用和人类的关系。 主题单元问题设 生物圈中有哪些绿色植物, 计 专题一:藻类植物 (2课时) 专题二:苔藓和蕨类植物 专题划分 (2课时) 专题三:种子植物 (3课时) 专题一专题一藻类植物 所需课时本专题使用2课时 专题一概述 本专题内容在整个单元中起到引导的作用。通过本专题的学习，学生能够知道藻类植物的基本特征和生活环境，明白藻类植物在自然界中的作用及人类对藻类植物的利用。 专题学习目标 知识目标: 概述藻类植物的主要特征和生活环境。 能力目标: 说出藻类植物在自然界中的作用和与人类的关系。 情感态度价值观: 关注藻类植物的生存现状，形成环保意识。
绿色企业行动宣传标语
绿色企业行动宣传标语 标语，绿色企业行动宣传标语 1、绿色发展，有你才有意义，绿色建设，有你才更完美。 2、环保不分民族，生态没有国界。 3、绿色环保构建美好家园，优质服务打造精致企业。 4、碧水蓝天是我家，绿色生产靠大家。 5、青山绿水要靠你我他共同来维护。 6、打造一流绿色企业，为美好生活加油。 7、美丽油田，我是行动者。 8、落实绿色发展，央企责无旁贷。 9、树立水务形象，协调生产与水。 10、绿色企业，绿色家园，绿色企业，绿色中国。 11、做好环保每一处，携手共护水乡缘。 12、山不言，默背负；水不语，静容纳；绿水青山美石化。 13、树立绿色形象，协调生产与水。 14、保护环境光荣，污染环境可耻。 15、少开车，多步走，活到九十九。 16、石化应有自己的色彩。 17、践行绿色发展理念，守护美丽水乡油田。 18、守护水乡油田，奉献绿色能源。 19、绿色科技，人文内涵——中石化，可持续发展的践行者 20、倡低碳减排之风，走持续发展之路。 21、绿化美化净化看石化，靠你靠我靠他靠大家。 22、让我们与绿色同行，让绿色与我们共生。 23、绿色采购绿色供应，转型发展新愿景。 24、做好维护保养，杜绝跑冒滴漏。 25、垃圾分类，达标排放；保护环境，造福人民。 26、坚持企业优化，促进环境保护。
27、与绿色拥抱，生活更美好。 28、回家吧，回到绿色生产的美好。 29、环保是健康之基，绿色是和谐之源 30、坚持水务发展，促进环境保护。 31、用我们的双手，描绘绿色的家园。 32、绿色成就石化。 33、绿色环保低碳行，节能创效做先锋。 34、低碳环保，绿色生产，我们一直在行动。 35、保护石化环境，共建绿色家园。 36、守护蓝天白云，碧水青山，绿色石化等你回家。 37、万绿丛中一点“石化”。 38、汽油柴油，不如绿水长流；春风十里，不如绿色有你。 39、足下留一寸，换来四时春。 40、让中国石化阳光普照，让绿色企业神圣美妙。 41、水乡油田我的家，绿色生产人人夸。 42、绿色石化福社会，青山绿水笑开颜。 43、建优美环境，筑优良业绩，做优秀社管人。 44、让家园更美，让生活更好。 45、绿色发展，科技创新——中石化，带您畅享低碳生活。 46、垃圾分类回收是物有价值，分类投放是人有素质。 47、共建青山绿水，共享幸福安康。 48、聚焦碧水蓝天净土心动，攻关安全环保节能技术。 49、爱的魔力转圈圈，绿色生产让人心花怒放不知疲倦。 50、手牵手维护绿色家园，心连心构筑和谐石化。 51、爱护环境，是我们每一位石油人应尽的责任。 52、发展诚可贵，效益价更高；若为环保故，两者皆可抛。 53、开发资源立足绿色生态，油气稳产呵护碧水蓝天。 54、石化实说：我喜欢绿色。 55、将绿色进行到底，让绿荫遍布天下。
小班化语文教学案例——《清平乐-村居》
小班化语文教学案例——《清平乐村居》 【设计理念】 在课程标准的理念指导下，结合小班化教学的特点，本课的教学设计力求体现：1、师生、生生的互动。2、教学与活动相结合。3、面向全体，异质教学。4、针对个体，同质活动。 【教学内容】 《清平乐村居》是小学语文五年级上册的一篇课文。课文描绘了一幅充满农村生活气息的田园图景。词的上阕长短句相间，而下阕句式整齐，每句韵脚相同，节奏感强。全词描绘了南方一户农家生活劳动的场景：二老融洽，孩子孝顺，老有所养，少有所事，温馨、淳朴，自然。 【学习目标】 １．正确、流利、在感情地朗读课文，在读中感悟田园生活的意境。使学生从中受到美的熏陶；背诵课文。 ２．学会本课５个生字。理解由生字组成的词语。 ３．初步了解词的有关知识。 ４．理解这首词的意思。想象这首词所描绘的情景，并在说的基础上写下来。 【学习小组的建构】 本课的学习小组先采用异质组合的分组法，再采用异质组队的分组法。根据各项语文学习能力（思维能力、朗读能力、书写能力、口语表达能力等）的强弱进行组合。本班共有24人，分为6组，每组4人，分别为1,2,3,4号。把1、2、3、4号同学，在异质组合的分组法中1、2、3、4号同学作为学习伙伴，其中1号为本小组组长，语文阅读，书写等综合能力较强，2号为本小组中相对较弱的同学，3,4号属于中等水平。在异质组队的分组法所有1号的同学座位一组，所有2号的同学也作为一组，所有3号一组，所有4号一组为一组。 【教学过程】 一．导入新课 1.、师：读读我们以前学过的课文，也有一种情趣，我们二年级学过词串： 金秋烟波水乡 芦苇菱藕荷塘 夕阳归舟渔歌 枫叶灯火月光
《新课标下高中数学概念教学的实践与研究》
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初中生物生物圈中的绿色植物知识点
初中生物生物圈中的绿 色植物知识点 Company number【1089WT-1898YT-1W8CB-9UUT-92108】
第三单元 生物圈中的绿色植物 第一章 生物圈中有哪些绿色植物 1、绿色植物分为四大类群：藻类、苔藓、蕨类、种子植物 一、藻类、苔藓、蕨类植物 2、藻类、苔藓、蕨类植物的区别： 3、藻类，苔藓，蕨类植物的共同点：藻类，苔藓，蕨类植物都不结种子， 它们的叶片背面有孢子囊群，可产生孢子，称为孢子植物，孢子是一种生殖细胞，在温暖潮湿的地方才能萌发和生长，所以说孢子植物的生活离不开水。 4.藻类植物：“春水绿于染” 5.藻类植物既有单细胞，也有多细胞。既有生活在淡水中，也有海水中。 6.多细胞藻类植物整个身体浸没在水中，几乎全身都可以吸收水和无机盐。可以进行光合作用，但没有专门吸收和运输养料以及进行光合作用的器官。 藻类植物 苔藓植物 蕨类植物 生活环境 大多数生活在水中 阴湿陆地上 阴湿陆地上 形态结构特征 没有根、茎、叶的分化 矮小，有茎和叶的分化（茎中无导管，叶中无叶脉），根是假根 有根茎叶的分化，有输导组 织 与人类关 系 释放氧气 监测空气污染的指示植物 遗体形成煤 矿 常见种类 水绵，衣藻，海带等 墙藓，葫芦藓等 肾蕨，满江红等
7.藻类植物没有根茎叶的分化。 8.苔藓植物生存在阴湿环境中。有类似根和茎的分化，但是茎中没有导管，叶中没有叶脉，根很简单，称为假根，具有固定作用。 9.苔藓植物可作为监测空气污染程度的指示植物。 10.蕨类植物：有根茎叶的分化，具有输导组织。有些蕨类植物比较高大。 11.蕨类植物用处：①卷柏、贯众可药用②满江红是一种优良绿肥和饲料③蕨类植物遗体层层堆积，经过漫长年代、复杂变化，逐渐变成了煤。 12.藻类植物，苔藓植物，蕨类植物，生殖依靠孢子，所以也被统称为孢子植物。 第二节 二、种子植物 1.、种子的结构 菜豆种子：种皮、胚(胚芽、胚轴、胚根、2片子叶)【双子叶植物，网状叶脉】 玉米种子：果皮和种皮、胚(胚芽、胚轴、胚根、1片子叶)、胚乳【单子叶植物，平行叶脉】 种皮：保护里面幼嫩的胚。 胚：新植物体的幼体，由胚芽（发育成茎和叶）、胚轴（发育成连接根和茎的部位）、胚根（发育成根）和子叶组成。胚乳不是胚的结构。 2、子叶和胚乳里有营养物质，供给胚发育成幼苗。 3、菜豆种子中与子叶相连的结构是胚轴，玉米种子中滴加碘液变蓝的结构 是胚乳，说明胚乳中含有淀粉。
企业环保标语口号
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19、保护环境，持续发展。 20、这天节约一滴水，留给后人一滴血。 21、守护健康人生，畅享财富自由。 22、产品买环保，处理少烦恼。 23、全面建设小康社会，同心共创完美家园。 24、需求无限，资源有限；善用有限，发展无限。 25、有限的资源，无限的循环。 26、以法保护自然环境，以德建立社会礼貌。 27、环保生活，健康财富。 28、做良心企业，为您的完美生活的保驾护航。 29、改善环境，创建美好未来是我们共同的愿望。 30、欣赏荒野、回归自然。 31、天蓝水清，地绿居佳。 32、心飞翔，身康健，天下一片绿色。 33、与环保同行，与财富共进。 34、用心迎接挑战，实现持续发展。 35、环保畅享绿色人生，健康乐活财富自由。 36、做世界一流环保产品，让地球人都身体康健，给财富自由的翅膀。 37、环保健康手牵手，财富自由心连心。 38、绿色是性命之源，绿色是人类之根。 39、美好的环境来自我们每个人的珍惜和维护。
初中生物绿色植物试题
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A.藻类植物 B.蕨类植物 C.裸子植物 D.被子植物 15. “人间四月芳菲尽，山寺桃花始盛开”。造成这一差异的非生物因素主要是
企业使命标语环保
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17、绿色节能，创造财富。 18、低碳生活，让你要拥有一切。 19、健康有保障，财富更自由。 20、呼吸洁净空气，享受财富生活。 21、环保生活，健康一生，财富自由，不悔此生。 22、现在做环保，未来当富豪。 23、环保是健康的保证，健康是财富的本钱，财富是自由的天地。 24、节能为环保，财富为健康。 25、悠然一心，财富自由。 26、做节能环保小先锋，享自由财富新生活。 27、健康，环保，财富，三者良性循环。 28、环保创财富，健康奔自由。 29、快乐环保，享受健康，经济自由。 30、做世界一流环保产品，让地球人都身体康健，给财富自由的翅膀。 31、尽环保力量，谋健康财富。 32、践行环保理念，扞卫健康生活。 33、节能就是创造财富，节能就是环保健康。 34、打造中国最优节能环保品牌。 35、更环保，更健康，更自由。 36、环保靠大家，健康你我他，财富和自由就有啦。
小班化小学语文课堂教学模式
小班化小学语文课堂教学模式 凤凰镇何田小学朱建平 小班化教学是建立在素质教育高标准，高要求的教育质量观和现代办学效益观基础上，充分发发挥“小班”本质特征的教学模式。现就有关教学策略方面浅谈几点体会。 一、教学方式的重组 在小班化教学模式中，师生之间的互动关系应得到增强和增加。 1、建立和谐的师生关系。教学是师生间交流沟通的过程，教师要和学生共同分享对教材的理解、课堂给予的快乐。教师的责任就是要成为学生学习的引导者、帮扶者和促进者。教师要转变教育观念，关心学生的心理需求，尊重学生的个性表达，营造一种平等宽容、健康和谐的课堂教学氛围。 2、营造浓郁学习氛围的教室环境。学生是课堂教学的主体，小班化教室环境的布置要以学生为本位，从有利于学生学习成长、有利于教师实施个别化教学去考虑。要把教室布置成为一个学习中心，营造浓郁的书香氛围。如可以在教室内悬挂励志格言、经典名句，张贴学生优秀作品，设立班级小书库，在课桌椅的排列上采取个体独立式或小组组合式，摆放成圆形、方框形、辩论型式、等等，以方便学生开展自学思考、课堂练习和进行一些互动沟通、讨论交流。 3、创设科学的教学情境。教师要注意采取各种方法激发学生强烈的求知欲望，引导学生迅速进入最佳语文学习状态，使他们在兴趣盎然的心理气氛中，跟着教师进入新知识的探索过程中。从教学需要出发，营造或创设与教学内容相适应的场景，力求生动、形象、有趣，以激发他们学习的兴趣，引起学生的情感体验，帮助学生迅速而正确地理解教材内容，促进儿童知识的、能力的、智力的、情感意志的尽可能大的发展。 二、自主探究策略 尊重和落实学生在课堂教学中的主体地位，注重学生在课堂内的自主探究，还学生以学习主动权，让学生有独立认知、思考的过程，是新课改的重要理念之
新课标下如何进行高中数学概念教学
新课标下如何进行高中数学概念教学 发表时间：2011-01-26T17:01:56.810Z 来源：《少年智力开发报》2010年第9期供稿作者：杨昆 [导读] 如何在这一要求下进行数学概念教学？我认为抓好概念教学是提高数学教学质量的最关键的一环。 贵州省平塘民族中学杨昆 教师应该准确地提示概念的内涵与外延，使学生深刻理解概念，并在解决各类问题时灵活应用数学概念是新课标下数学概念的教学要求。因此正确理解数学概念，是掌握数学基础知识的前提。如何在这一要求下进行数学概念教学？我认为抓好概念教学是提高数学教学质量的最关键的一环。下面我从引入概念、解析概念、巩固概念三个方面谈谈对概念教学。 一、引入概念 概念教学中要引导学生经历从具体的实例抽象出数学概念的过程．因此引入数学概念就要以具体的典型材料和实例为基础，揭示概念形成的实际背景，要创设好的问题情境，帮助学生完成由材料感知到理性认识的过渡，并引导学生把背景材料与原有认知结构建立实质性联系．下面介绍几种引入数学概念的方法： 1.从实际生活中，引入新概念。 新课标强调“数学教学要紧密联系学生的生活实际”．在数学概念的引入上，尽可能地选取学生日常生活中熟悉的事例． 2.创设问题情境，引入新概念。 教师要善于恰当地创设趣味性、探索性的问题情境，激发学生概念学习的兴趣，使学生能够从问题分析中，归纳和抽象出概念的本质特征，这样形成的概念才容易被学生理解和接受。 3. 从最近概念引入新概念。 数学概念具有很强的系统性。数学概念往往是“抽象之上的抽象”，先前的概念往往是后续概念的基础，从而形成了数学概念的系统。公理化体系就是这种系统性的最高反映。教学中充分利用学生头脑中已有的知识与相关的经验引入概念，使相应的具体经验升华为理性认识，不仅能使学生准确地理解概念的形式定义，而且有利于建立起关于概念的恰当心理表征。使学生对知识的积累变成对知识的融合。 二、解析概念 生动恰当的引入概念，只是概念教学的第一步，，要使学生真正掌握新概念，还必须多角度、多方位的解析概念。对概念理解不深刻，解题时就会出现这样或那样的错误，要正确而深刻地理解一个概念并不是一件容易的事，教师要根据学生的知识结构和能力特点，从多方面着手，适当地引导学生正确地分析解剖概念，充分认识概念的科学性，抓住概念的本质。因此，教师要充分利用概念课，培养学生的能力，训练学生的思维，使学生认识到数学概念，既是进一步学习数学的理论基础，又是进行再认识的工具。为此，我们可以从以下几个方面努力，加深对概念的理解。 1.用数学符号语言解析概念。数学教学体现了数学语言的特点，数学语言无非是文字叙述、符号表示、图形表示三者之间的转换，当然要会三者的翻译，同时更重要的是强调符号感。引进数学符号以后，应当引导学生把符号与它所代表的实质内容联系起来，使学生在看到符号时就能够联想起符号所代表的概念及其本质特征。事实上，如果概念的符号能够与概念的实质内容建立起内在联系，那么，符号的掌握可以提高学生的抽象能力、概括能力。数学中的逻辑推理关键就在于能够合理、恰当地应用符号，而这又要依靠对符号的实质意义的把握。在概念学习中，形式地掌握符号而不懂得符号的本质涵义的情况是经常发生的，这时符号将使知识学习产生困难，导致数学推理的错误。 2.用图形语言解析概念。数与形的结合是使学生正确理解和深刻体会概念的好方法，数形结合妙用无穷，教学中凡是“数”与“形”能够结合起来讲的，一定要尽量结合起来讲。 3.逆向分析，加深对概念的理解。人的思维是可逆的，但必须有意识地去培养这种逆向思维活动的能力。对某些概念还应从多方面设问并思考。 4.讲清数学概念之内涵和外延，沟通知识的内在联系。概念反映的所有对象的共同本质属性的总和，叫做这个概念的内涵，又称涵义。适合于概念所指的对象的全体，叫做这个概念的外延，又称范围。 5.揭示概念与概念之间的区别与联系,使新概念与已有认知结构中的有关概念建立联系,把新概念纳入到已有概念体系中,同化新概念。教学中，应将相近、相反或容易混淆的概念放到一块来对比讲解，从定义、图形、性质等各方面进行分析对比，从而正确理解把握概念.。 三、巩固概念 学生认识和形成概念，理解和掌握之后，巩固概念是一个不可缺少的环节。巩固的主要手段是多练习、多运用，只有这样才能沟通概念、定理、法则、性质、公式之间的内存联系。我们可以选择概念性、典型性的习题，加强概念本质的理解，使学生最终理解和掌握数学思想方法。例如，当学习完“向量的坐标”这一概念之后，进行向量的坐标运算，提出问题：已知平行四边形ABCD的三个顶点ABC的坐标分别是(1,2),(2,4),(0,2),试求顶点D的坐标。学生展开充分的讨论，不少学生运用平面解析几何中学过的知识（如两点间的距离公式、斜率、直线方程、中点坐标公式等），结合平行四边形的性质，提出了各种不同的解法，有的学生应用共线向量的概念给出了解法，还有一些学生运用所学过向量坐标的概念，把点D的坐标和向量CD的坐标联系起来，巧妙地解答了这一问题。学生通过对问题的思考，尽快地投入到新概念的探索中去，从而激发了学生的好奇以及探索和创造的欲望，使学生在参与的过程中产生内心的体验和创造。除此之外，教师通过反例、错解等进行辨析，也有利于学生巩固概念。 总之，在中学数学概念的教学中，只要针对学生实际和概念的具体特点，注重引入，加强分析，重视训练，辅以灵活多样的教法，使学生准确地理解和掌握概念，才能更好地完成数学概念的教学任务，从而有效地提高数学教学质量。