巴雷特图法在化工成本分析中的应用

巴雷特图形已广泛地应用在化工生产管理、质量管理等领域 。

煤化工企业成本管理的难点及对策分析

近些年,国际国内的经济形势并不明朗,改革开放以后,各种企业的蓬勃发展,引发的诸如行业竞争,企业管理等问题在最近几年表现的愈发明显,在这样的环境下,新兴工业煤化工企业在生产和利润同时实现当前的发展问题需要解决。本文为探究煤化工企业成本管理的难点和对策,综合分析了煤化工行业成本管理与管理的必要性和困难,进一步探索煤化工成本管理对策和建议,以期对煤化工成本管理工作起到一定的推动作用。

浅谈石油化工工程项目采购管理中的成本控制

石油化工是国民经济中尤为重要的基础工业,是战略性新兴产业发展的基础,目前,我国经济发展进入了新阶段,即面临着新的机遇,也面临着新的挑战。在新常态下,国内市场潜力巨大,为石油化工行业提供了长期、稳定的需求。所以,加强采购成本的控制是降低工程造价、优化资源合理配置的关键。

运筹学软件CrystalBall在联合化工生产过程的应用

降低成本是生产型企业不变的主题,本文主要是利用先进的管理优化类软件CrystalBall将工厂进行数学建模,从而可以快速准确的计算每种生产情况下的最优生产计划,帮助企业降低生产成本,实现最优化运营。

Study on the Landscaping Technologies for Coastal Saline-Alkali Land in Tanghai County of Tangshan City

Tanghai County is one of the counties in Tangshan City with the highest saline-alkali degree, with 80% of its land being covered by saline-alkali soils. Through studying landscaping technologies for coastal saline-alkali land in Tanghai County, 3 dominant modes for landscaping engineering in such land were summarized as shallow underground pipe desalination technology, banding soil replacement technology and hole membrane soil replacement technology, which are different in application scope and also in cost (respectively 260, 210 and 170 yuan). 3 landscaping measures were also proposed, including promotion of suitable plant cultivation technologies, application of saline-alkali tolerant plants and biological improvement of soils. To explore economic and practical planting patterns for saline-alkali land, low-cost landscaping tests were conducted from the perspectives of improving landscaping engineering mode and optimizing landscaping measures, and the results showed that it was practical to apply low-cost landscaping patterns, and comprehensive ecological measures should be adopted to realize the sustained utilization of soil.

A Genetic Algorithm-based Approach to Scheduling of Batch Production with Maximum Profit

The optimal scheduling of multi-product batch process is studied and a new mathematics model targeting the maximum profit is proposed, which can be solved by the modified genetic algorithm (MGA) with mixed coding (sequence coding and decimal coding) developed by us. In which, the partially matched cross over (PMX) and reverse mutation are used for the sequence coding, whereas the arithmetic crossover and heteropic mutation are used for the decimal coding. In addition, the relationship between production scale and production cost is analyzed and the maximum profit is always a trade-off of the production scale and production cost. Two examples are solved to demonstrate the effectiveness of the method.

Technical Challenges and Progress in Fluidized Bed Chemical Vapor Deposition of Polysilicon

Various methods for production of polysilicon have been proposed for lowering the production cost andenergy consumption, and enhancing productivity, which are critical for industrial applications. The fluidized bed chemical vapor deposition （FBCVD） method is a most promising alternative to conventional ones, but the homogeneous reaction of silane in FBCVD results in unwanted formation of fines, which will affect the product qualityand output. There are some other problems, such as heating degeneration due to undesired polysilicon deposition on the walls of the reactor and the heater. This article mainly reviews the technological development on FBCVD of polycrystalline silicon and the research status for solving the above problems. It also identifies a number of challenges to tackle and principles should be followed in the design ofa FBCVD reactor.

VPLS Based Quality and Cost Control for Tennessee Eastman Process

Product quality and operation cost control obtain increasing emphases in modern chemical system engineering. To improve the fault detection power of the partial least square (PLS) method for quality control, a new QRPV statistic is proposed in terms of the VP (variable importance in projection) indices of monitored process variables, which is significantly advanced over and different from the conventional Q statistic. QRPV is calculated only by the residuals of the remarkable process variables (RPVs). Therefore, it is the dominant relation between quality and RPV not all process variables (as in the case of the conventional PLS) that is monitored by this new VP-PLS (VPLS) method. The combination of QRPV and T2 statistics is applied to the quality and cost control of the Tennessee Eastman (TE) process, and weak faults can be detected as quickly as possible. Consequently, the product quality of TE process is guaranteed and operation costs are reduced.

New Development of Port Structures Design and Construction

Some new innovative constructions and technologies for improvement of port structures are worked out and discussed. The aims of innovations are to increase structures＇ reliability, to decrease cost of construction and maintenance, to simplify technology and cost of building. For these purposes either some main bearing elements or structures in whole are modified or improved. In particular different improved waterfront constructions as well as retaining walls and coastal protection （gravity, piled, sheet piling, etc.） for use in various soil conditions are outlined. One of them incorporates trapezoidal blocks forming columns, each block in the column contacts the others either with smaller or larger bases. Another design incorporates blocks that are constructed with holes ran through the centres of gravity of the blocks. Rigid cylinder element running through the holes of several adjacent blocks allows them to be joined forming large size units, The structure consisting of wedge form retaining wall is original but simple to construct, Some new designs based on perfection of sheet-piling walls （sheet piles with curvilinear cross-section having a form of semi-rings） are proposed for different applications. Proposals on modernization of some traditional structures and technologies are discussed.

Value Source of Integrated Refining/Chemical Plant

Based on an integrated refining/chemical plant processing 15 Mt/a of crude and manufacturing 1.0 Mt/a of ethylene under the guideline of＂engaging in refining, olefins and aromatics by whatever appropriate means＂ to maximize the overall value of the integrated refining/chemical plant, it is necessary to concentrate on working on the flow diagram and the solution for mutual supply of materials between the refinery and ethylene plant. After analyzing the feedstock slate, the composition and properties of products, it is proposed to optimize the integrated refming/chemical plant in order to reduce investment and operating cost to realize maximization of the value of the integrated plant.

聚乙烯胺在箱纸板上的生产应用试验

探讨了聚乙烯胺对箱板纸生产的影响。结果表明,聚乙烯胺不仅能提高纸张的耐破指数,而且可以减少系统中阴离子垃圾含量,提高系统清洁度;同时还可以降低聚丙烯酰胺(PAM)的用量和面层木浆的配比,起到降低生产成本的作用。

Ecological Costs Applied in the Bleaching of Cotton： A Study for an Optimized Process

The aim of this paper was to study three variables in hydrogen peroxide bleaching of cotton fabrics： the amount of hydrogen peroxide （H2O2）, peroxide stabilizer （Na2SiO3） and the process temperature. The factorial planning of two levels and three factors was done in order to obtain an optimized recipe for subsequent comparison with commons recipes used in industry. Were evaluated the brightness （DL）, energy consumption （dQ）, H2O2 residual （Rox）, processing time and ecological costs.

Multi-objective nonlinear model predictive control through switching cost functions and its applications to chemical processes

This paper proposes a switching multi-objective model predictive control(MOMPC) algorithm for constrained nonlinear continuous-time process systems.Different cost functions to be minimized in MPC are switched to satisfy different performance criteria imposed at different sampling times.In order to ensure recursive feasibility of the switching MOMPC and stability of the resulted closed-loop system,the dual-mode control method is used to design the switching MOMPC controller.In this method,a local control law with some free-parameters is constructed using the control Lyapunov function technique to enlarge the terminal state set of MOMPC.The correction term is computed if the states are out of the terminal set and the free-parameters of the local control law are computed if the states are in the terminal set.The recursive feasibility of the MOMPC and stability of the resulted closed-loop system are established in the presence of constraints and arbitrary switches between cost functions.Finally,implementation of the switching MOMPC controller is demonstrated with a chemical process example for the continuous stirred tank reactor.

A matting method based on color distance and differential distance

A new matting algorithm based on color distance and differential distance is proposed to deal with the problem that many matting methods perform poorly with complex natural images.The proposed method combines local sampling with global sampling to select foreground and background pairs for unknown pixels and then a new cost function is constructed based on color distance and differential distance to further optimize the selected sample pairs.Finally,a quadratic objective function is used based on matte Laplacian coming from KNN matting which is added with texture feature.Through experiments on various test images,it is confirmed that the results obtained by the proposed method are more accurate than those obtained by traditional methods.The four-error-metrics comparison on benchmark dataset among several algorithms also proves the effectiveness of the proposed method.

Layout Design-Based Research on Optimization and Assessment Method for Shipbuilding Workshop

The research study proposes to examine a three-dimensional visualization program, emphasizing on improving genetic algorithms through the optimization of a layout design-based standard and discrete shipbuilding workshop. By utilizing a steel processing workshop as an example, the principle of minimum logistic costs will be implemented to obtain an ideological equipment layout, and a mathematical model. The objectiveness is to minimize the total necessary distance traveled between machines. An improved control operator is implemented to improve the iterative efficiency of the genetic algorithm, and yield relevant parameters. The Computer Aided Tri-Dimensional Interface Application （CATIA） software is applied to establish the manufacturing resource base and parametric model of the steel processing workshop. Based on the results of optimized planar logistics, a visual parametric model of the steel processing workshop is constructed, and qualitative and quantitative adjustments then are applied to the model. The method for evaluating the results of the layout is subsequently established through the utilization of AHP. In order to provide a mode of reference to the optimization and layout of the digitalized production workshop, the optimized discrete production workshop will possess a certain level of practical significance.

Long Run Relationships, Vertical Integration and International Competition： Can They Contribute to Explaining Regional Construction Cost Differences？

The existence of opportunistic behavior by contractors or sub-contractors in the bidding process encouraged by the governance structure of construction companies as well as the kind of relationship that exist between contractors and clients is thought to have some bearing on the rising construction cost observed in some regions of Sweden. Three hypotheses that are intended to test the impact that long run relationship between contractors and developers, vertically integrated firms, and the increase of international competition could have on the construction cost increase levels were tested on a predetermined number of projects from six cities in different regions. The semi-structured survey produces inconclusive results. Long run and collaborative relationship was prevalent in small region though respondents in this region did not draw strong connection between construction cost increase levels and the kind of observed relationship. In Stockholm region, short-term relationship was mostly prevalent. Vertical integration and foreign competition impacts on construction costs were not significant in either region.

Fuzzy Logic Based Approach in an Enterprise Resource Planning System for Hydraulic Cylinders Assembly

Trends in modern industry show a tendency towards demassovization of production as a response to the customers＇ specific needs for unique and personalized products. This provokes significant changes in the processes of manufacturing, assembly, and testing The cost of such a type of production can be reduced by employing highly productive reconfigurable equipment with proper software to enable optimization. This paper presents a decision support extension for directing of hydraulic cylinders to assembly-testing lines using fuzzy logic in the Enterprise Resource Planning system of a small size production in a factory in Bulgaria. Different assembly-testing lines are flexibly assigned to the specific cylinder＇s parameters by the developed fuzzy system on the basis of the overlapping of parameters in the hydraulic cylinders classification. The final decision on the line assigned in case of alternatives is made through accounting for the minimal cylinder delay time. The effectiveness of the approach is assessed by simulation. It leads to an increase of the efficiency of the assembly-testing flow lines, a reduction of the time needed for hydraulic cylinders assembling and testing and balanced loading of the modules.

Present situation and improving measures of Chinese Construction Engineering Management informatization

Building engineering management is a huge and complex work, which the key to ensure the quality ofconstruction projects. With the rapid development of the domestic construction industry, the traditional engineering management model can not meet the needs of a large number of construction project information exchanges. Only realizing informationization of construction engineering management, can reduce the cost of construction projects, improve the efficiency of project management and construction progress. This paper analyzes the current situation of construction management informatization, and puts forward some suggestions to strengthen the construction management information construction.