浅谈消防水池的设计

比较了《建筑设计防火规范》和上海市《民用建筑水灭火系统设计规程》对消防水池设置的不同规定,结合工程实例,对合理优化设置消防水池提出建议。

稀见善本《资治通鉴大全》考辨

沈阳师范大学图书馆现藏明刻本《资治通鉴大全》382卷,该书为[明]路进校辑并出版,为史学专科丛书。此书以时为纲记事为目,记载了中国古代上迄伏羲氏下至明崇祯元年以前近七千年的历史。目前在国内外未见有完整著录或存藏,被视为辽宁省珍贵古籍,具有重要的版本价值及历史文献价值。

医院给水系统设计若干问题探讨

为满足医院建筑对供水安全的要求,对给水系统用水量计算、洁净手术部供水设计、防止水质污染、分质供水、热水供应等问题进行了分析,并结合工程案例提出相应处理措施。结果表明:用水量计算时需计入陪护人员用水,洁净手术部等对供水要求较高的科室,其两路进水形式的选择需充分考虑供水可靠性和经济性,给水系统自市政接入端至供水点均设置防止水质污染的措施,分质供水设计采用集中预处理+分散深度处理的形式更为经济合理,热水系统采用集中和分散相结合的形式所在满足供水需求的同时降低造价和运行成本。本文成果可为医院建筑给排水设计提供一定的借鉴和参考。

Improved ant colony optimization for multi-depot heterogeneous vehicle routing problem with soft time windows

Considering that the vehicle routing problem （VRP） with many extended features is widely used in actual life, such as multi-depot, heterogeneous types of vehicles, customer service priority and time windows etc., a mathematical model for multi-depot heterogeneous vehicle routing problem with soft time windows （MDHVRPSTW） is established. An improved ant colony optimization （IACO） is proposed for solving this model. First, MDHVRPSTW is transferred into different groups according to the nearest principle, and then the initial route is constructed by the scanning algorithm （SA）. Secondly, genetic operators are introduced, and crossover probability and mutation probability are adaptively adjusted in order to improve the global search ability of the algorithm. Moreover, the smooth mechanism is used to improve the performance of the ant colony optimization （ACO）. Finally, the 3-opt strategy is used to improve the local search ability. The proposed IACO was tested on three new instances that were generated randomly. The experimental results show that IACO is superior to the other three existing algorithms in terms of convergence speed and solution quality. Thus, the proposed method is effective and feasible, and the proposed model is meaningful.

Wrinkling behavior of magnesium alloy tube in warm hydroforming

In tube hydroforming with axial feeding,under the effect of coupled internal pressure and axial stress,wrinkles often occur and affect the forming results.Wrinkling behavior of an AZ31B magnesium alloy tube was experimentally investigated with different loading paths at different temperatures.Features of wrinkles,including shape,radius and width,were acquired from the experiments,as well as the thickness distribution.Numerical simulations were carried out to reveal the stress state during warm hydroforming,and then the strain history of material at the top and bottom of the wrinkles were analyzed according to the stress tracks and yielding ellipse.Finally,effects of loading paths on expansion ratio limit of warm hydroforming were analyzed.It is verified that at a certain temperature,expansion ratio limit can be increased obviously by applying a proper loading path and realizing enough axial feeding.

Kinetics modeling for austenite transformation in AISI 1045 steel during rapid heating under high frequency electromagnetic field

To investigate the effect of alternating magnetic field on austenite transformation process in the case of rapid heating,the austenite kinetics model of AISI 1045 steel was built for spot continual induction hardening(SCIH)process.The results shows that the effect of alternating magnetic field on austenite transformation fraction reaches the maximum(about 3%)when heating rate is the lowest.Relatively low magnetic flux density still has a certain effect on the austenite transformation process during the SCIH process.Concave surface structure can reduce the influence scope of alternating magnetic field on surface in all cases and the minimum influence scope appears when the feed path of inductor is longitudinal.Convex surface structure can minimize the influence scope of alternating magnetic field in depth when the feed path of inductor is longitudinal.The austenite distribution of transitional region on surface for horizontal movement is more uniform than that for longitudinal movement.The austenite distribution of transitional region in depth for longitudinal movement is more uniform than that for horizontal movement.The simulated results are consistent with the experimental results and the austenite transformation kinetics model developed for SCIH process is valid.

RPL Based on Triangle Module Operator for AMI Networks

the routing protocol for low-power and lossy networks(RPL) has been used in advanced metering infrastructure(AMI)which could provide two-way communication between smart meters and city utilities.To improve the network performance of AMI networks, this paper proposed an improved algorithm of RPL based on triangle module operator(IAR-TMO). IAR-TMO proposes membership functions of the following five typical routing metrics: end-to-end delay, number of hops, expected transmission count(ETX),node remaining energy, and child node count.Moreover, IAR-TMO uses triangle module operator to fuse membership functions of these routing metrics. Then, IAR-TMO selects preferred parents(the next hop) based on the triangle module operator. Theoretical analysis and simulation results show that IAR-TMO has a great improvement when compared with two recent representative algorithms: ETXOF(ETX Objective Function) and OF-FL(Objective Function based on Fuzzy Logic), in terms of network lifetime, average end-to-end delay,etc. Consequently, the network performances of AMI networks can be improved effectively.

Schematic Road Network Map Progressive Generalization Based on Multiple Constraints

Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a con- crete experiment while maintaining topological consistency of the road network between the original and the schematic map

Day-to-day traffic user equilibrium model considering influence of intelligent highways and advanced traveler information systems

To explore the influence of intelligent highways and advanced traveler information systems(ATIS)on path choice behavior,a day-to-day(DTD)traffic flow evolution model with information from intelligent highways and ATIS is proposed,whereby the network reliability and experiential learning theory are introduced into the decision process for the travelers’route choice.The intelligent highway serves all the travelers who drive on it,whereas ATIS serves vehicles equipped with information systems.Travelers who drive on intelligent highways or vehicles equipped with ATIS determine their trip routes based on real-time traffic information,whereas other travelers use both the road network conditions from the previous day and historical travel experience to choose a route.Both roadway capacity degradation and travel demand fluctuations are considered to demonstrate the uncertainties in the network.The theory of traffic network flow is developed to build a DTD model considering information from intelligent highway and ATIS.The fixed point theorem is adopted to investigate the equivalence,existence and stability of the proposed DTD model.Numerical examples illustrate that using a high confidence level and weight parameter for the traffic flow reduces the stability of the proposed model.The traffic flow reaches a steady state as travelers’routes shift with repetitive learning of road conditions.The proposed model can be used to formulate scientific traffic organization and diversion schemes during road expansion or reconstruction.

Multi-objective evolutionary approach for UAV cruise route planning to collect traffic information

Unmanned aerial vehicle(UAV)was introduced as a novel traffic device to collect road traffic information and its cruise route planning problem was considered.Firstly,a multi-objective optimization model was proposed aiming at minimizing the total cruise distance and the number of UAVs used,which used UAV maximum cruise distance,the number of UAVs available and time window of each monitored target as constraints.Then,a novel multi-objective evolutionary algorithm was proposed.Next,a case study with three time window scenarios was implemented.The results show that both the total cruise distance and the number of UAVs used continue to increase with the time window constraint becoming narrower.Compared with the initial optimal solutions,the optimal total cruise distance and the number of UAVs used fall by an average of 30.93% and 31.74%,respectively.Finally,some concerns using UAV to collect road traffic information were discussed.

Road Foundation Improvement by Explosive Force

A highway was constructed in Jiangxi Province, China, through mountainous area. Some sections of the highway went through valleys where a soft clay layer of 6,8.5 m deep was encountered. A new explosive method was developed and adopted for this project. In this method, blasting is used to remove and replace soft clay with crushed stones. Explosive charges are placed in the soil to be improved according to a certain pattern. Crushed stones are piled up behind the area where charges are installed. The explosion removes most of the soil in the exploded area and causes the pile of crushed stones to slide into the area where the soil is removed by blasting. A formular was suggested to calculate the charge weight used for improving a certain type of soil. The effectiveness of the method is evaluated using borehole exploration, plate load tests,and ground-probing radar tests.

Calculation method for station carrying capacity of high-speed railway based on station blocking time method

A station carrying capacity calculation method based on the station blocking time method is proposed.According to the station track circuit groups,signal system and station topological structure,the station blocks are divided and the division principle is proposed.Then the train routes model is built based on the station blocking time method.The calculation methods of the train arrival headway and departure headway at the station are redefined.The optimal capacity calculation model and algorithm based on a given train operation plan are studied by analyzing the optimal operation sequence of trains with different train speeds and operation types.With the case study of Jinan West Railway Station of Beijing-Shanghai high-speed railway in China,the minimum arrival headway between two trains with the speeds of 300 and 250 km/h can be reduced to 3.0 and 2.7 min,respectively.The maximum calculation results of the calculation methods can be increased from 13 train/h to 16 train/h.This method can increase the number of trains within a period of time in a station while meeting the transport organization and passenger service requirements.

Discrete element method of improved performance of railway ballast bed using elastic sleeper

With the development of high-speed and heavy-haul railway in China, problems like insufficient thickness of ballast bed and overlarge track stiffness are obvious. Ballast may break into small particles and their contact status will deteriorate under cyclic loading, resulting in ballast degradation. Discrete element method(DEM) was used to research improved performance of ballast bed using elastic sleeper. Clusters were generated by bonding spheres to model real ballasts, while broken bonds were utilized to distinguish breakage. Two kinds of ballast beds with elastic sleeper and conventional sleeper were established, respectively. After applying cyclic loading to the models, differences of mechanical properties between two models were analyzed by contrasting their dynamic behavior indexes, such as particle contact force, sleeper settlement, vibration velocity and acceleration, breakage characteristic. The results illustrate that compared with conventional sleeper, elastic sleeper increases sleeper settlement, while reduces ballast vibration and contact force between particles, which could depress ballast breakage.

Efficient and reliable road modeling for digital maps based on cardinal spline

In order to realize an optimal balance between the efficiency and reliability requirements ofroad models,a road modeling method for digital maps based on cardinal spline is studied.First,the cardinal spline is chosen to establish an initial road model,which is specified by a series of control points and tension parameters.Then,in view of the initial road model,a gradual optimization algorithm,which can determine the reasonable control points and optimal tension parameters according to the degree of the change of road curvature,is proposed to determine the final road model.Finally,the proposed road modeling method is verified a d evaluated through experiments,and it is compared with the conventional method for digital maps based on the B-spline.The results show that the proposed method can resize a neaoptimal balance between the efficiency and reliability requirements.Compared with the conventional method based on the B-spline,this method occupies less data storage and achieves higher accuracy.

An analytical method to calculate station evacuation capacity

The major objective of this work was to calculate evacuation capacity and solve the optimal routing problem in a given station topology from a network optimization perspective where station facilities were modelled as open finite queueing networks with a multi-objective set of performance measures. The optimal routing problem was determined so that the number of evacuation passengers was maximized while the service level was higher than a certain criterion. An analytical technique for modelling open finite queueing networks, called the iteration generalized expansion method(IGEM), was utilized to calculate the desired outputs. A differential evolution algorithm was presented for determining the optimal routes. As demonstrated, the design methodology which combines the optimization and analytical queueing network models provides a very effective procedure for simultaneously determining the service level and the maximum number of evacuation passengers in the best evacuation routes.

Solving material distribution routing problem in mixed manufacturing systems with a hybrid multi-objective evolutionary algorithm

The material distribution routing problem in the manufacturing system is a complex combinatorial optimization problem and its main task is to deliver materials to the working stations with low cost and high efficiency. A multi-objective model was presented for the material distribution routing problem in mixed manufacturing systems, and it was solved by a hybrid multi-objective evolutionary algorithm (HMOEA). The characteristics of the HMOEA are as follows: 1) A route pool is employed to preserve the best routes for the population initiation; 2) A specialized best?worst route crossover (BWRC) mode is designed to perform the crossover operators for selecting the best route from Chromosomes 1 to exchange with the worst one in Chromosomes 2, so that the better genes are inherited to the offspring; 3) A route swap mode is used to perform the mutation for improving the convergence speed and preserving the better gene; 4) Local heuristics search methods are applied in this algorithm. Computational study of a practical case shows that the proposed algorithm can decrease the total travel distance by 51.66%, enhance the average vehicle load rate by 37.85%, cut down 15 routes and reduce a deliver vehicle. The convergence speed of HMOEA is faster than that of famous NSGA-II.

“Assahlahmu Alaykum...”

Lured by the exoticism of frontier towns and an untouched market, enterprising foreigners head west on China’s Silk Road.

A GIS-Based Evaluation of Environmental Sensitivity for an Urban Expressway in Shenzhen, China

Urban eco-environmental degradation is becoming inevitable due to the extensive urbanization, popula- tion growth, and socioeconomic development in China. One of the traffic arteries in Shenzhen is an urban expressway that is under construction and that runs across environmentally sensitive areas （ESAs）. The environmental pollution from urban expressways is critical, due to the characteristics of expressways such as high runoff coefficients, considerable contaminant accumulation, and complex pollutant ingredi- ents. ESAs are vulnerable to anthropogenic disturbances and hence should be given special attention. In order to evaluate the environmental sensitivity along this urban expressway and minimize the influences of the ongoing road construction and future operation on the surrounding ecosystem, the environmental sensitivity of the relevant area was evaluated based on the application of a geographic information sys- tem （GIS）. A final ESA map was classified into four environmental sensitivity levels; this classification indicates that a large proportion of the expressway passes through areas of high sensitivity, representing 11.93 km or 52.3% of the total expressway, and more than 90% of the total expressway passes through ESAs. This study provides beneficial information for optimal layout schemes of initial rainfall runofftreatment facilities developed from low-impact development （LID） techniques in order to minimize the impact of polluted road runoff on the surrounding ecological environment.

Three-dimensional multi-constraint route planning of unmanned aerial vehicle low-altitude penetration based on coevolutionary multi-agent genetic algorithm

To address the issue of premature convergence and slow convergence rate in three-dimensional (3D) route planning of unmanned aerial vehicle (UAV) low-altitude penetration,a novel route planning method was proposed.First and foremost,a coevolutionary multi-agent genetic algorithm (CE-MAGA) was formed by introducing coevolutionary mechanism to multi-agent genetic algorithm (MAGA),an efficient global optimization algorithm.A dynamic route representation form was also adopted to improve the flight route accuracy.Moreover,an efficient constraint handling method was used to simplify the treatment of multi-constraint and reduce the time-cost of planning computation.Simulation and corresponding analysis show that the planning results of CE-MAGA have better performance on terrain following,terrain avoidance,threat avoidance (TF/TA2) and lower route costs than other existing algorithms.In addition,feasible flight routes can be acquired within 2 s,and the convergence rate of the whole evolutionary process is very fast.

GIS-Based Simulation of Engineering Construction Schedule

For its complexity, engineering construction schedule design is limited by various factors.Simulation-based engineering construction schedule takes critical path method (CPM) network as frame and calls complex cyclic operation network (CYCLONE) simulation model enclosed in advance for its simulation nodes. CYCLONE simulation model takes charge of simulating stochastic duration of activity and efficiency of resources, while CPM model performs project scheduling. This combination avoids the shortcomings of both models. Furthermore, geographic information system (GIS) technique is utilized to visualize the construction processes which are otherwise difficult to be understood by static results described. Application in practical project verifies the feasibility and advantage of the technique.