基于度时法的齐河县采暖强度和节能潜力分析

根据齐河县2006—2016年逐小时气温资料,利用数理统计、度时法等对该县冬季集中供暖期内气温和采暖强度时间分布和变化特征进行分析。结果表明:(1)齐河县每年固定采暖时间为121 d,供暖期小时平均气温一日内最低值出现在07时,为-1.0℃,最高值出现在15时,为7.4℃;日平均气温最低值出现在1月23日,为-3.1℃,最高值出现在3月11日,为9.6℃;逐月平均气温1月最低,为-1.4℃,3月最高,为6.3℃,供暖期年平均气温平均值为2.6℃,2012年最低,2014年最高。(2)多年小时平均采暖强度平均值为15.4℃·h,一日内呈现单峰型分布,最高值出现在07时,为19.0℃,最低值出现在15时,为10.7℃。逐月小时采暖强度平均值3月最小,为11.8℃·h,1月最大,为19.4℃·h。一日内各小时平均采暖强度最小值,11月和12月出现在14时和15时,其余月份均只出现在15时;一日内各小时平均采暖强度最大值,3月出现在06时和07时,其余月份均只出现在07时。(3)供暖期各月累积采暖强度3月最低,1月最高。年累积平均采暖强度平均值为4.7×10^(4)℃·h,2014年最低,2012年最高。

再谈混凝土强度推算法

对“谈《建筑工程冬施规程》与混凝土强度推算法”一文的讨论。依据强度推算法发展历史讨论了成熟度法与强度龄期曲线法的区别并论及试验数据选用的必要性。从统一基础数据角度制定了模拟函数的数学基本条件以及比较了指数函数与幂函数的适用性。

Rolling horizon scheduling algorithm for dynamic vehicle scheduling system

Dynamic exclusive pickup and delivery problem with time windows (DE-PDPTW), aspecial dynamic vehicle scheduling problem, is proposed. Its mathematical description is given andits static properties are analyzed, and then the problem is simplified asthe asymmetrical travelingsalesman problem with time windows. The rolling horizon scheduling algorithm (RHSA) to solve thisdynamic problem is proposed. By the rolling of time horizon, the RHSA can adapt to the problem'sdynamic change and reduce the computation time by dealing with only part of the customers in eachrolling time horizon. Then, its three factors, the current customer window, the scheduling of thecurrent customer window and the rolling strategy, are analyzed. The test results demonstrate theeffectiveness of the RHSA to solve the dynamic vehicle scheduling problem.

遵义市办公建筑自然通风潜力研究

作为一种有效的通风方式,自然通风不仅能够减少能耗、降低污染,而且带来的新鲜空气也有利于人的心理和生理健康。对于住宅建筑,开窗通风降温是一种惯常做法,但对于办公建筑,由于其较大的内部热负荷,较小的围护结构比例,自然通风的应用并不具有普遍适应性,存在一定的地域差异。为了研究遵义地区办公建筑采用自然通风的潜力,以遵义市典型年气象参数为依据,首先绘制四季风玫瑰图,整理并分析全年风速分布,然后采用度时法,计算遵义地区办公建筑的自然通风潜力。

空调全年动态负荷估算

介绍常用动态负荷计算软件,并通过工程实例,提出采用度日法计算冬季热负荷,用度时法计算夏季冷负荷,以供借鉴。

Novel operating theatre scheduling method based on estimation of distribution algorithm

In order to improve the efficiency of operating rooms,reduce the costs for hospitals and improve the level of service qualities, a scheduling method was developed based on an estimation of distribution algorithm（ EDA）. First, a scheduling problem domain is described. Based on assignment constraints and resource capacity constraints, the mathematical programming models are set up with an objective function to minimize the system makespan. On the basis of the descriptions mentioned above, a solution policy of generating feasible scheduling solutions is established. Combined with the specific constraints of operating theatres, the EDA-based algorithm is put forward to solve scheduling problems. Finally, simulation experiments are designed to evaluate the scheduling method. The orthogonal table is chosen to determine the parameters in the proposed method. Then the genetic algorithm and the particle swarm optimization algorithm are chosen for comparison with the EDA-based algorithm, and the results indicate that the proposed method can decrease the makespan of the surgical system regardless of the size of operations. Moreover, the computation time of the EDA-based algorithm is only approximately 5 s when solving the large scale problems, which means that the proposed algorithm is suitable for carrying out an on-line scheduling optimization of the patients.

Probabilistic durability assessment approach of deteriorating RC bridges

A stochastic finite element computational methodology for probabilistic durability assessment of deteriorating reinforced concrete（RC） bridges by considering the time-and space-dependent variabilities is presented.First,finite element analysis with a smeared cracking approach is implemented.The time-dependent bond-slip relationship between steel and concrete,and the stress-strain relationship of corroded steel bars are considered.Secondly,a stochastic finite element-based computational framework for reliability assessment of deteriorating RC bridges is proposed.The spatial and temporal variability of several parameters affecting the reliability of RC bridges is considered.Based on the data reported by several researchers and from field investigations,the Monte Carlo simulation is used to account for the uncertainties in various parameters,including local and general corrosion in rebars,concrete cover depth,surface chloride concentration,chloride diffusion coefficient,and corrosion rate.Finally,the proposed probabilistic durability assessment approach and framework are applied to evaluate the time-dependent reliability of a girder of a RC bridge located on the Tianjin Binhai New Area in China.

A novel particle swarm optimizer without velocity:Simplex-PSO

A simplex particle swarm optimization(simplex-PSO) derived from the Nelder-Mead simplex method was proposed to optimize the high dimensionality functions.In simplex-PSO,the velocity term was abandoned and its reference objectives were the best particle and the centroid of all particles except the best particle.The convergence theorems of linear time-varying discrete system proved that simplex-PSO is of consistent asymptotic convergence.In order to reduce the probability of trapping into a local optimal value,an extremum mutation was introduced into simplex-PSO and simplex-PSO-t(simplex-PSO with turbulence) was devised.Several experiments were carried out to verify the validity of simplex-PSO and simplex-PSO-t,and the experimental results confirmed the conclusions:(1) simplex-PSO-t can optimize high-dimension functions with 200-dimensionality;(2) compared PSO with chaos PSO(CPSO),the best optimum index increases by a factor of 1×102-1×104.

Try and error-based scheduling algorithm for cluster tools of wafer fabrications with residency time constraints

To improve the productivity of cluster tools in semiconductor fabrications,on the basis of stating scheduling problems,a try and error-based scheduling algorithm was proposed with residency time constraints and an objective of minimizing Makespan for the wafer jobs in cluster tools.Firstly,mathematical formulations of scheduling problems were presented by using assumptions and definitions of a scheduling domain.Resource conflicts were analyzed in the built scheduling model,and policies to solve resource conflicts were built.A scheduling algorithm was developed.Finally,the performances of the proposed algorithm were evaluated and compared with those of other methods by simulations.Experiment results indicate that the proposed algorithm is effective and practical in solving the scheduling problem of the cluster tools.

Application of predictive control scheduling method to real-time periodic control tasks overrun

Based on the abort strategy of fixed periods, a novel predictive control scheduling methodology was proposed to efficiently solve overrun problems. By applying the latest control value in the prediction sequences to the control objective, the new strategy was expected to optimize the control system for better performance and yet guarantee the schedulability of all tasks under overrun. The schedulability of the real-time systems with p-period overruns was analyzed, and the corresponding stability criteria was given as well. The simulation results show that the new approach can improve the performance of control system compared to that of conventional abort strategy, it can reduce the overshoot and adjust time as well as ensure the schedulability and stability.

Multiple linear system techniques for 3D finite element method modeling of direct current resistivity

The strategies that minimize the overall solution time of multiple linear systems in 3D finite element method (FEM) modeling of direct current (DC) resistivity were discussed. A global stiff matrix is assembled and stored in two parts separately. One part is associated with the volume integral and the other is associated with the subsurface boundary integral. The equivalent multiple linear systems with closer right-hand sides than the original systems were constructed. A recycling Krylov subspace technique was employed to solve the multiple linear systems. The solution of the seed system was used as an initial guess for the subsequent systems. The results of two numerical experiments show that the improved algorithm reduces the iterations and CPU time by almost 50%, compared with the classical preconditioned conjugate gradient method.

A sensor transaction scheduling algorithm for maintaining real-time data temporal validity

A new scheduling algorithm called deferrable scheduling with time slice exchange (DS-EXC) was proposed to maintain the temporal validity of real-time data. In DS-EXC, the time slice exchange method was designed to further defer the release time of transaction instances derived by the deferrable scheduling algorithm (DS-FP). In this way, more CPU time would be left for lower priority transactions and other transactions. In order to minimize the scheduling overhead, an off-line scheme was designed. In particular, the schedule for a transaction set is generated off-line until a repeating pattern is found, and then the pattern is used to construct the schedule on-line. The performance of DS-EXC was evaluated by sets of experiments. The results show that DS-EXC outperforms DS-FP in terms of increasing schedulable ratio. It also provides better performance under mixed workloads.

Real-Time Spreading Thickness Monitoring of High-core Rockfill Dam Based on K-nearest Neighbor Algorithm

During the storehouse surface rolling construction of a core rockfilldam, the spreading thickness of dam face is an important factor that affects the construction quality of the dam storehouse' rolling surface and the overallquality of the entire dam. Currently, the method used to monitor and controlspreading thickness during the dam construction process is artificialsampling check after spreading, which makes it difficult to monitor the entire dam storehouse surface. In this paper, we present an in-depth study based on real-time monitoring and controltheory of storehouse surface rolling construction and obtain the rolling compaction thickness by analyzing the construction track of the rolling machine. Comparatively, the traditionalmethod can only analyze the rolling thickness of the dam storehouse surface after it has been compacted and cannot determine the thickness of the dam storehouse surface in realtime. To solve these problems, our system monitors the construction progress of the leveling machine and employs a real-time spreading thickness monitoring modelbased on the K-nearest neighbor algorithm. Taking the LHK core rockfilldam in Southwest China as an example, we performed real-time monitoring for the spreading thickness and conducted real-time interactive queries regarding the spreading thickness. This approach provides a new method for controlling the spreading thickness of the core rockfilldam storehouse surface.

A Discrete Artificial Bee Colony Algorithm for Minimizing the Total Flow Time in the Blocking Flow Shop Scheduling

A discrete artificial bee colony algorithm is proposed for solving the blocking flow shop scheduling problem with total flow time criterion. Firstly, the solution in the algorithm is represented as job permutation. Secondly, an initialization scheme based on a variant of the NEH (Nawaz-Enscore-Ham) heuristic and a local search is designed to construct the initial population with both quality and diversity. Thirdly, based on the idea of iterated greedy algorithm, some newly designed schemes for employed bee, onlooker bee and scout bee are presented. The performance of the proposed algorithm is tested on the well-known Taillard benchmark set, and the computational results demonstrate the effectiveness of the discrete artificial bee colony algorithm. In addition, the best known solutions of the benchmark set are provided for the blocking flow shop scheduling problem with total flow time criterion.

FPGA-based High-precision Measurement Algorithm for the Ultrasonic Echo Time of Flight

Based on the evaluation of advantages and disadvantages of high-precision digital time interval measuring algorithms, and combined with the principle of the typical time-difference ultrasonic flow measurement, the requirements for the measurement of echo time of flight put forward by the ultrasonic flow measurement are analyzed. A new high-precision time interval measurement algorithm is presented, which combines the pulse counting method with the phase delay interpolation. The pulse counting method is used to ensure a large dynamic measuring range, and a double-edge triggering counter is designed to improve the accuracy and reduce the counting quantization error. The phase delay interpolation is used to reduce the quantization error of pulse counting for further improving the time measurement resolution. Test data show that the systexn for the measurement of the ultrasonic echo time of flight based on this algorithm and implemented on an Field Programmable Gate Army（FleA） needs a relatively short time for measurement, and has a measurement error of less than 105 ps.

Impact of Soil Water Flux on Vadose Zone Solute Transport Parameters

The transport processes of solutes in two soil columns filled with undisturbed soil material collected from an unsaturated sandy aquifer formation in Belgium subjected to a variable upper boundary condition were identified from breakthrough curves measured by means of time domain reflectometry (TDR). Solute breakthrough was measured with 3 TDR probes inserted into each soil column at three different depths at a 10 minutes time interval. In addition, soil water content and pressure head were measured at 3 different depths. Analytical solute transport models were used to estimate the solute dispersion coefficient and average pore-water velocity from the observed breakthrough curves. The results showed that the analytical solutions were suitable in fitting the observed solute transport. The dispersion coefficient was found to be a function of the soil depth and average pore-water velocity, imposed by the soil water flux. The mobile moisture content on the other hand was not correlated with the average pore-water velocity and the dispersion coefficient.

Scheduling algorithm of dual-armed cluster tools with residency time and reentrant constraints

To solve the scheduling problem of dual-armed cluster tools for wafer fabrications with residency time and reentrant constraints,a heuristic scheduling algorithm was developed.Firstly,on the basis of formulating scheduling problems domain of dual-armed cluster tools,a non-integer programming model was set up with a minimizing objective function of the makespan.Combining characteristics of residency time and reentrant constraints,a scheduling algorithm of searching the optimal operation path of dual-armed transport module was presented under many kinds of robotic scheduling paths for dual-armed cluster tools.Finally,the experiments were designed to evaluate the proposed algorithm.The results show that the proposed algorithm is feasible and efficient for obtaining an optimal scheduling solution of dual-armed cluster tools with residency time and reentrant constraints.

Grinding analysis of Indian coal using response surface methodology

The present work discusses a systematic approach to model grinding parameters of coal in a ball mill. A three level Box-Behnken design combined with response surface methodology using second order model was applied to the experiments done according to the model requirement. Three parameters ball charge （numbers 10-20）, coal content （100-200 g） and the grinding time （4-8 rain） were chosen for the experiments as well as for the modeling work. Coal fineness is defined as the dso （80 % passing size）. A quadratic model was developed to show the effect of parameters and their interaction with fineness of the product. Three different sizes （4, 1 and 0.65 mm） of Indian coal were used. The model equations for each fraction were developed and different sets of experiments were performed. The predicted values of the fineness of coal were in good agreement with the experimental results （R2 values of dso varies between 0.97 and 0.99）. Fine size of three different coal sizes were obtained with larger ball charge with less grinding time and less solid content. This work represents the efficient use of response surface methodology and the Box-Behnken design use for grinding of Indian coal.

PID Controller Design Based on the Time Domain Information of Robust IMC Controller Using Maximum Sensitivity

The IMC(Internal Model Control) controller based on robust tuning can improve the robustness and dynamic performance of the system.In this paper,the robustness degree of the control system is investigated based on Maximum Sensitivity(Ms) in depth.And the analytical relationship is obtained between the robustness specification and controller parameters,which gives a clear design criterion to robust IMC controller.Moreover,a novel and simple IMC-PID(Proportional-Integral-Derivative) tuning method is proposed by converting the IMC controller to PID form in terms of the time domain rather than the frequency domain adopted in some conventional IMC-based methods.Hence,the presented IMC-PID gives a good performance with a specific robustness degree.The new IMC-PID method is compared with other classical IMC-PID rules,showing the flexibility and feasibility for a wide range of plants.

Optimization of enzyme assisted extraction of polysaccharides from Ganoderma lucidum

In the present work,an enzyme assisted extraction method is used to isolate crude polysaccharides from Ganoderma lucidum. The isolating effect was optimized with orthographic graph statistic method with three levels and four independent variables. Complex enzyme,extraction temperature,extraction time and extraction pH were combined to obtain the best possible combination to get maximum amount of extract and crude polysaccharides yield. The optimum extraction conditions were:complex enzyme amount of 3 %(w/v),extraction temperature at 45 ℃,extraction time of 3 h and extraction pH at 7. Under these conditions,the experimental amount of extract is 8.9 % and the yield of crude polysaccharides is 1.1 %,which are in close agreement with the value predicted by the model.