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Affected by various uncertain factors, the critical chain is random. The article studies the critical chain and its randomness, and points out that when there is no buffer, the critical chain method and the critical path method have the same identity, and the central limit law of the same distribution can solve the randomness of the critical chain. This conclusion is mainly based on the following research: (1) The paper analyze the technical points of the critical chain, and points out that the setting of the buffer can be replaced by the operation time of the process; (2) The principles and expressions are proposed for determining the critical chain; (3) The influence factors of the randomness of the critical chain are analyzed; (4) The randomness of the random critical chain is determined based on the central limit law of the same distribution.

Industry is an important pillar of the national economy, and industrial projects are the most complex and difficult to manage and control in the construction industry; thus, the resource scheduling control of industrial projects is one of the core issues for industrial construction projects. The performance rate of the contract time periods of previous industrial construction projects has been very low. In scheduling control based on case-based reasoning (CBR), the goal is to implement preventive measures by referring to existing scheduling control cases and control the scheduling of resources through reasoning on emergency measures to prevent scheduling control deviations. In this paper, the rough set approach is used to represent the case feature information in a case reasoning model for industrial project scheduling control, attribute reduction is used to determine the weights of the feature attributes in the rough set representation, and the similarity between cases is calculated for case retrieval. The accuracy of the rough-set-based similarity calculation is verified through matrix similarity calculations and a visual analysis of the all closeness centrality and weighted all degree centrality of the corresponding complex network; thus, similar cases of industrial project scheduling control are identified. To verify the applicability and effectiveness of the proposed methodology, a typical coal chemical general contract project case is carried out. The rough set comprehensive similarity results were 0.733, 0.621, 0.536, 0.614, 0.559, 0.950, 0.708, 0.546, 0.733, 0.664, 0.526, and 0.743, and the matrix similarity results were 0.417, 0.583, 0.417, 0.417, 0.417, 0.833, 0.417, 0.500, 0.417, 0.500, 0.333, and 0.500. The results showed that the case retrieval accuracy of traditional matrix similarity is not as high as the rough set comprehensive similarity, so X 6 is the most similar case to the target case Y. Case retrieval results indicate that the proposed methodology can provide a good similar case selection strategy with project managers, and the final required preventive measures for the target case can be found. Based on the identified similar cases, preventive measures for scheduling control are formulated to effectively prevent scheduling deviations of industrial projects.

Industry is an important pillar of the national economy. Industrial projects are the most complex and difficult projects to control in the construction industry, and major industrial projects are even more complex and difficult to control. Multi-agent coordination is one of the core issues of industrial projects. Based on an analysis of the engineering and construction chains and agent relationships and agent networks of industrial projects, a complex network of the engineering and construction agents of industrial projects is established, and the complex network structural holes theory is applied to study the nonrepeated relationships among agents in industrial projects. Assuming agents are linked through contract relations and the most critical contract index between the agents in the contract amount, through structural hole analysis considering the EPC and PMC model, the aggregate constraint list is obtained, 2D network diagram and 3D network diagram are shown. According to the aggregate constraint value, the EPC contractor with the minimum aggregate constraint value and the project management company with the minimum aggregate constraint value are the critical agent in EPC and PMC model. By analyzing the complex network comprising different models of industrial projects, it is concluded that the characteristics of the agent maintain an advantage in competition, the coordination mechanism of the integration of agent interests, and multi-agent relations are considered to solve the multi-agent coordination problem in major industrial projects.

It has been widely accepted in the academic community that the Critical Chain Method (CCM) has significant advantages over the Critical Path Method (CPM) in solving the problem with resource constraints. However, this paper conducted a study on comparing the two methods of Critical Chain Method and Critical Path Method, and found that the only difference between those two methods lies in how to determine the priority of resources allocating, and on the assumption of not setting buffer zone, those two methods have no essential distinctions at all. By establishing the relationship between CCM and CPM, this paper also enriched and improved CCM to some extent, and pointed out that the buffer zone setting in CCM is merely subjective and short of scientificity. In the meantime, for the problem of unclear representation of critical chains, it proposed two ways of representing critical chains and related rules to follow. To verify the conclusion of this paper, further detailed case study of comparing CCM and CPM was performed. Affected by various uncertain factors, the project construction sequence is random, the total construction duration is random, and the critical chain is also random, so it is unable to determine how to direct construction. Aiming at the randomness of the critical chain, this article analyzed various uncertain factors of the critical chain, and on the basis of solving the critical chain sequence time, it proposed the approach to determine the completion probability of the total construction duration and control the construction of the critical chain to direct the construction, in the meantime, the inverse algorithm was adopted to determine of the construction duration under the condition of required completion probability.

In this paper, the average molecular structure models of middle-low temperature coal tar (MLCT) asphaltene before and after hydrogenation were obtained by 1H-NMR characterization. Then the aggregation structure models of MLCT asphaltenes before and after hydrogenation was constructed in Materials Studio 8.0 software. The comparative analysis of structural characteristics between original and hydrogenated asphaltenes were carried out. The final configuration, molecular rotation radius and interaction energy of asphaltene aggerates before and after hydrogenation were analyzed by molecular dynamic simulation in different solvents.The conclusions are as follows: (1) The MLCT asphaltenes exist in the form of asphaltene aggregates before and after hydrogenation. After structural optimization, the original asphaltene molecules become 2-3 asphaltene molecules with approximately parallel, orderly arrangement and polycyclic aromatic hydrocarbons (PAH) stacking aggregate structure. The molecular accumulation number of its aggregate is less than that of petroleum asphaltene, and more complex nano-aggregates are formed by self-assembly among multiple aggregates. The accumulation number of asphaltene molecules after MLCT hydrogenation are less than that of original asphaltene. (2) The total interaction between MLCT primary asphaltene and hydrogenated asphaltene mainly comes from the intermolecular Van der Waals force. Compared with original asphaltene, the van der Waals energy and electrostatic energy of hydrogenated asphaltene are smaller and more affected by temperature. This shows that the intermolecular interaction of hydrogenated asphaltene is weak and the structure of the aggregate is unstable. (3) Aromatic compounds, strong basic compounds and strong polar compounds have good dissociation effect on MLCT asphaltenes and can effectively inhibit the aggregation and asphaltenes.

Electricity in the retail market has a different value for different types of consumers. Therefore, different retail prices are usually determined for various consumers in the retail market. However, imposed risks from uncertain parameters are a big challenge in the real-time retail market pricing process. This paper proposed a real-time pricing (RTP) framework for various users including residential, commercial, and industrial consumers by the electricity retailer. In addition, uncertainties of various input parameters such as output power of renewable energy resources, electricity demand, and pool market price are modeled using scenario-based stochastic approach while downside risk constraints method is proposed to model risk associated with uncertainties. By implementing this method, electricity retailer will be able to select various risk-based strategies. Furthermore, numerical results illustrate the various risks versus various profits by the occurring of each scenario which helps the retailer for decisions-making in different scenarios. According to obtained results, retailer by choosing of zero risk strategy can reduce its risk by 100% while expected profit is reduced by 2.07%. In addition, offered RTP by the retailer is higher for industrial, commercial, and residential customers, respectively. Finally, risk-averse and risk-neutral strategies of electricity retailer are determined in the power procurement problem.

The organics in the water after advanced treated and to be disinfected are classified basing on different characteristics. Compared with chlorination, the control of DBPs formation from different organics by chloramination is studied. The test results show that, the chloramine can reduces the TTHM and THAA formation from hydrophilic organics by 90.8% and 77.5%, and from organics with molecular size

Concentration plant site selection is an complex system engineering. The traditional site selection schemes were too simple, only comparing on the technical and economic indicators of the schemes, but cross combinations between the various economic indicators were ignored. Through a comparative analysis of existing site selection method we explore the shortcomings of them, and then made extended time Petri net method for site selection. Combining the characteristics of the model, using Ant Colony optimization algorithm have solved the time Petri nets model of site selection. Practice has demonstrated that the model will be introduced in the mine site selection instance through computer simulation, selected the best location efficient path.

the main factors which influence the recirculation under cooling tower are analyzed theoretically, the experimental model tests are also carried out to discuss the affect extent of factors to recirculation under cooling tower, the results can provide theoretical direction in decreasing and avoiding recirculation under cooling tower

In the past ten years, there is an elevating tendency of Xi’an economy development and carbon emissions. Using co-integration analysis method and Eviews6.0 software we proved that there is co-integration relation and bi-directional causality between the Xi’an economy growth and carbon emissions. Then the authors analyzed the pulling effect and the efficiency from the role of the economic growth and industrial structure on carbon emissions by applying the error correction model. Based on the results, we proposed the operation mechanism and policy proposal. It provides theoretical and practical significance on Xi’an low carbon economy development.

The study of the methodology of the green degree evaluating for building assemblies is one of the vital issues of realization of the green building. This paper studies the classification of building assemblies, constructs an evaluating indicator system for the green degree of the building assemblies, proposes the methodology of the green degree measuring for the evaluating indicators, and by the application of one-dimension information diffusing, computer simulation, two-dimension information diffusing, curve fitting etc., establishes the function of the building assembly's green degree, and constitutes the system of the methodology of the green degree evaluating for building assemblies.