烟草柔性制丝线排产算法的研究与应用

提出利用不同的排产调度方法与技术有机地集成来解决烟草行业的排产问题。以某卷烟制造企业作为研究和应用背景,对烟草排产中的工艺流程和约束规则进行分析,构建制丝车间排产双层架构模型,运用双向排产调度技术与产品优化组合技术,将排产中的约束规则嵌入到算法设计过程中,给出算法设计方案,并通过实例说明此算法能够很好地适应企业制丝线排产的需要。     

应用技术学院排课管理系统的研究与开发

黑龙江八一农垦大学应用技术学院排课采用人工排课方式，针对人工排课具有效率低、易冲突、工作量大等弊端，运用管理信息系统技术原理与方法，结合实际排课需求，基于．NET技术研究开发了应用技术学院排课管理系统，很好地解决了上述问题，极大地提高了排课效率。     

A Study on the Job-shop Scheduling Problem

This paper discusses a new approach of job shop production scheduling with the time limit of starting and completing work.In this approach,all operations in the queue are sorted according to their values of remaining operating time,and a preliminary feasible solution of production scheduling is achieved,which makes a shortest circulation time of parts in the system.Then adjustment is made aiming at maximum ahead/behind time span of operation block.The process is iterated until a satisfactory scheduling solution is obtained.Through analysis and application proof,the scheduling algorithm is suitable and feasible in engineering projects.     

控制性交替灌溉对玉米生理生态及产量的影响

控制性交替灌溉技术是一种新兴灌溉技术。本文采用蒸渗仪对沈阳地区潮棕壤土条件下的玉米在不同控制性交替灌溉处理下的生长发育、生理生态指标、产量及其构成因子、水分利用率和经济效益进行分析,提出了适合当地条件的玉米优化控制性交替灌溉制度,为该技术在东北地区的推广和应用提供理论依据。     

基于储能水平控制的微电网能量优化调度

为了充分发挥微电网中储能单元能量存储与搬移的作用,该文提出了以储能单元储能水平为微电网日前计划与实时计划之间联系纽带的多时间尺度能量优化调度方案,以及以储能水平为控制变量的日前计划优化模型。该优化模型以各可控型微电源出力、储能单元储能水平以及微网与主网交互功率均在限值之内和微网内功率平衡为约束条件,以可再生能源发电利用率最高、日供电成本最小为目标函数,通过满足"等效净负荷"需求达到可再生能源发电利用率最高的目标。采用基于矩阵实数编码的遗传算法求解该动态优化模型,算例验证了并网双向功率流动、并网单向功率流动2种模式下模型和方法的有效性。研究结果可为微电网能量优化调度决策方案提供参考。     

Assessing basin irrigation and scheduling strategies for saving irrigation water and controlling salinity in the upper Yellow River Basin, China

Water saving in irrigation is a key concern in the Yellow River basin. Excessive water diversions for irrigation waste water and produce waterlogging problems during the crop season and soil salinization in low lands. Supply control and inadequate functionality of the drainage system were identified as main factors for poor water management at farm level. Their improvement condition the adoption of water saving and salinity control practices. Focusing on the farm scale, studies to assess the potential for water savings included: (a) field evaluation of current basin irrigation practices and further use of the simulation models SRFR and SIRMOD to generate alternative improvements for the surface irrigation systems and (b) the use of the ISAREG model to simulate the present and improved irrigation scheduling alternatives taking into consideration salinity control. Models were used interactively to define alternatives for the irrigation systems and scheduling that would minimize percolation and produce water savings. Foreseen improvements refer to basin inflow discharges, land leveling and irrigation scheduling that could result in water savings of 33% relative to actual demand. These improvements would also reduce percolation and maintain water table depths below 1 m thereby reducing soil salinization.     

Accuracy of canopy temperature energy balance for determining daily evapotranspiration

The application of a single-layer canopy temperature energy balance (CTEB) model for determining integrated daily ET rates was tested, with possible applications towards determining irrigation requirements (“how much to irrigate”) as a complement to crop water stress index (CWSI) measurements (“when to irrigate”), an irrigation scheduling tool which uses much of the same data. Evapotranspiration (ET) rates estimated using the CTEB model were compared to Bowen ratio energy balance (BREB) measurements made over substantial portions of the growing seasons of corn and potato crops. Canopy temperature, net radiation and soil heat flux data were collected and analyzed at 20-minute intervals, and ET for each interval was summed to obtain daily and multi-day estimations. Only full canopy conditions were examined. Two methods for atmospheric stability correction were applied to the aerodynamic resistance required by the CTEB model; an iterative procedure proposed by Campbell, and a second procedure proposed by Monteith which uses an adjustment coefficient. To reduce instrumentation requirements for combined CTEB/CWSI data collection, estimates of ET were also determined using net radiation and soil heat flux values estimated from solar radiation measurements. Results showed that uncorrected CTEB ET estimates agreed reasonably well with BREB measurements over corn and potato canopies (RMSE = 0.5 to 0.7 mm day⁻ for observed average ET ranging from 4.8 to 5.5 mm day⁻, with a trend toward seasonal overprediction with corn. Stability corrections usually lowered the daily RMSE 0.1 to 0.2 mm day⁻, with seasonal ET more in agreement with BREB ET. The Monteith-based adjustment gave slightly better results. CTEB ET model with estimated net radiation and soil heat flux terms produced similar average and total ET, but somewhat larger daily errors (RMSE=0.5 to 0.9 mm day⁻). Seasonal total ET by the uncorrected CTEB model generally overestimated within 10% (ranging from 1% to 10%) of the observed BREB total ET, an acceptable error for most irrigation practices. Stability corrections generally caused seasonal ET to be underestimated within 1% to 9%.     

下级渠道流量不等时渠系优化配水模型与算法研究

目前国内外现有的渠道优化配水模型,都是在下级渠道配水流量相等这一假定条件的基础上建立的,这与绝大多数渠系实际配水要求不相符合。针对这一问题,建立了下级渠道引水流量不等情况下的渠道优化配水模型,研究了模型的遗传算法的编码及适应度设计方法,编制了VC程序,并用于冯家山灌区北干十一支共24条斗渠道的实际配水过程中进行了对比验证。结果表明,渠系优化配水过程较原配水过程斗渠配水时间搭配合理、支渠配水流量均匀,符合优化配水原则,渠系渗透损失水量比原方案可减少17.8%。表明模型及其求解算法是可行的,可为下级引水渠道流量不等时的渠系优化配水决策提供理论和技术支持。     

On-farm performance evaluation of improved traditional small-scale irrigation practices: A case study from Dire Dawa area, Ethiopia

Field evaluation of surface irrigation systems play a fundamental role to determine the efficiency of the system as it is being used and to identify management practices and system configurations that can be implemented to improve the irrigation efficiency. This study evaluated the performance of an ‘improved’ traditional small-scale irrigation practice at Adada, a representative small-scale irrigation practice in Dire Dawa Administrative Council, Eastern Ethiopia. In order to determine numerical values of performance measures, certain parameters were measured/observed before, during and after an irrigation event while farmers are performing their normal irrigation practice. These parameters include: irrigated crop, irrigation method, stream size, cutoff time, soil moisture deficiency, and field size, shape and spacing. The results showed that the irrigation water applied to a farmer's plot during an irrigation event/turn was generally higher than the required depth to be applied per event. Since the irrigation method used was end-dyked, the major cause of water loss was due to deep percolation. The deep percolation loss was 32% in sorghum, 57% in maize, and 70% in tomato and potato fields. The type of irrigation system used, the ridged irrigation practice and the poor irrigation scheduling in the study sites were the main problems identified in the management and operations of the schemes. The following corrective measures are recommended to improve the system: (1) farmers should regulate the depth of irrigation water they apply according to the type of crop and its growth stage, change the field irrigation system and/or configuration especially for shallow rooted row crops, to furrow system, (2) guidance and support to farmers in developing and introduction of appropriate irrigation scheduling, and (3) future development interventions towards improvement of traditional irrigation practices should also focus in improving the on farm irrigation systems in addition to improving physical infrastructure of the scheme.     

Introducing monitoring and evaluation into main system management — a low investment approach

The need to develop a framework for performance assessment of irrigation schemes is increasingly dominating discussions in the field of water management. This paper supports the view that the introduction of monitoring and evaluation of water distribution systems as a part of the day to day management activity is a desirable step in the improvement process and can be introduced at little cost.Data already being routinely collected in many schemes provide a valuable insight into scheme operation and can be used to improve planning of operating strategies. One aim of the study being carried out by Hydraulics Research and the Irrigation Department at Hakwatuna Oya in Sri Lanka is to improve the standards of main system management within the constraints of the existing physical infrastructure through the provision of timely performance data. A microcomputer has been installed at the project office to store and analyse rainfall, flow and field wetness data, and to provide performance reports on a regular basis. Early results suggest that the timely processing of an increased level of data collection is effective for both the identification of problems and the quantification of potential for improvement. Particular emphasis is given to providing the necessary software tools and training such that routine monitoring and evaluation becomes an accepted and sustainable proposition.