Search

The experimental investigation on the mechanical parameters compositions of glass-fiber reinforced plastic mortar (GRPM) pipe is the basis of simulating and analyzing the mechanical characteristics of the complete structure of GRPM pipe. Due to the anisotropic material properties of GRPM pipe, the compressive property test is carried out, and the results show that the circumferential compressive strength(CCS) is 49.93Mpa, the axial compressive strength(ACS) is 40.79Mpa, the circumferential elastic modulus(CEM) is 4.84Gpa, and the axial elastic modulus(AEM) is 4.04Gpa. The difference between the CCS and ACS and EM is about 20%, as well as the CCS and EM are greater than the ACS and modulus of elasticity. Conclusions drawn from the tests provide an important basis for checking whether the materials meet the design requirements.

Groundwater resources compose the essential foundation for the ecological conservation of the Chahannauer Basin. Exploring its spatial-temporal variation characteristics based on historical data provides a scientific basis for the restoration of the Chahannauer Basin and the sustainable utilization of groundwater. GIS technology was used to analysis the spatial interpolation of groundwater level in the Zhangjiakou Chaganore River Basin. Variation tendency of driving factors to groundwater level were assessed by The Mann-Kendall test, ordered clustering and nonlinear pettitt test. The radial basis function neural network (RBFNN) method was optimized to quantitatively assess the corresponding contribution of each driving factor to groundwater level. The results indicate a generally clear downward trend of the groundwater level in the area, especially after 2004, it has decreased significantly and after 2012 the underwater level showed a slight elevation. Among all the driving factors, precipitation and evaporation increased slightly while runoff showed a significant downward trend throughout the year. The groundwater extraction is positively correlated with the groundwater level dynamics, in which groundwater extraction has the largest contribution to groundwater level, followed by precipitation, runoff and evaporation. Variations of the groundwater level in the study area are temporally and specially affected mainly by human activities.

In this paper, a novel modified whale optimization algorithm based on Tent chaos map and tournament selection strategy (MWOA) was presented. The aim of the improved algorithm is to reduce the possibility of the standard whale algorithm falling into local optimal. During the initialization of the population, in order to increase population diversity and randomness, MWOA cites the Tent chaos map. In the optimization process, in order to improve the development ability of the standard algorithm, the tournament selection strategy was employed to improve the algorithm accuracy. Numerical simulation and example calculation results show that the improved algorithm is superior to the standard WOA algorithm. The improved method provides a new method for truss structure optimization.

The fuzzy logic reasoning based on the “If... then...” rule is not the inaccurate reasoning of AI against ambiguity because fuzzy reasoning is antilogical. In order to solve this problem, a redundancy theory for discriminative weight filtering containing six theorems and one M(1,2,3) model was proposed and the approximate reasoning process was shown, the system logic of AI handling ambiguity as an extension of the classical logic system was proposed. The system is a generalized dynamic logic system characterized by machine learning, which is the practical-application logic system of AI, and can effectively deal with practical problems including conflict, noise, emergencies and various unknown uncertainties. It is characterized by combining approximate reasoning and computing for specific data conversion through machine learning. Its core is data and calculations and the condition is “sufficient” high-quality training data. The innovation is that we proposed a discriminative weight filtering redundancy theory and designed a computable approximate reasoning logic system that combines approximate reasoning and calculation through machine learning to convert specific data. It is a general logic system for AI to deal with uncertainty. The study has significance in theory and practice for AI and logical reasoning research.

Asphalt aging has a direct influence on the durability of asphalt mixture. In order to improve thermal oxidizing aging resistance of asphalt, the commercial antioxidants including Irganox 1010 and Irgafos 168 were selected to modify base asphalt and SBR asphalt. The basic properties of modified asphalt before and after the rolling thin film oven test (RTFOT) are evaluated by penetration, softening point, ductility, and viscosity. The Fourier transform infrared spectroscopy (FTIR) test was applied to determine the antiaging mechanism of modified and unmodified asphalt. According to the test result, Irganox 1010 not only reduces the aging degree of asphalt but also has little adverse effect on other properties. Irgafos 168 with a content of 1% improves the low temperature ductility of asphalt and improves the antiaging performance of asphalt significantly. After RTFOT, the content of oxygen-containing functional groups (carbonyl group and sulfoxide group) declines significantly in antioxidation modified asphalt, and Irganox 1010 and Irgafos 168 inhibit oxidizing reaction in the aging procedure. This study can provide a useful reference for improving the aging property of asphalt in highway construction.

It is the key and difficult problem for the current project management to consider the multi-objective optimization of the four elements, such as quality, duration, cost and safety. To improve the accuracy and efficiency of project management during the engineering construction, considering the advantages and disadvantages of the traditional quality-cost-time model, the four elements were regarded as a system, and a multi-objective optimization model was established. The improved ant colony algorithm was used to carry out multi-objectives of construction projects to overcome the premature defect of the traditional method. The optimal plan of the project was found and the overall efficiency of the construction project management was improved. Results show the optimized ant colony algorithm can avoid the low efficiency of the optimal solution search and the shortcoming of the initial pheromone. The engineering practice proves that the enhanced algorithm has solved the problem of the multi-objective optimization of quality, duration, cost and safety. The obtained conclusions are of significant reference value to direct the similar engineering practice.

To improve the efficiency of the structural optimization design in truss calculation, an improved chicken swarm optimization algorithm was proposed for truss structure optimization. The chicken swarm optimization is a novel swarm intelligence algorithm. In the basic chicken swarm optimization algorithm, the concept of combining chaos strategy and reverse learning strategy was introduced in the initialization to ensure the global search ability. And the inertia weighting factor and the learning factor were introduced into the chick position update process, so as to better combine the global and local search. Finally, the overall individual position of the algorithm was optimized by the differential evolution algorithm. The improved algorithm was tested by multipeak function and applied to the truss simulation experiment. The study provided a new method for the truss structure optimization.

The main objective of this paper is to investigate the dynamic performance and behaviour of glass-fiber reinforced plastic (GRP) mortar pipes under heavy truck loads. According to the field conditions, a finite element dynamic analysis (FEDA) model of GRP pipe culverts was established. Modal analysis of the vibration system was carried out, and the main natural frequencies with 26.6Hz,32Hz,35.7Hz and corresponding mode shapes were obtained. On the basis of modal analysis, dynamic response of GRP pipe culverts under vehicle loads was simulated through random vibration. Based on the measured vibration velocity time histories, the modal and random vibration responses of the vibration system were analyzed. The results show that the spectral response value of pipeline to vehicle load decreases with the increase of buried depth. When the depth of GRP pipe culverts buried is greater than 0.8m, the influence of ground vehicle dynamic loads on the vibration of GRP pipe culverts cannot be taken into consideration. It can provide the basis for the design of GRP pipe culverts, especially under heavy loads.

In order to find a more effective method for the structural optimization, an improved fruit fly Optimization Algorithm was proposed. The dynamic adjustment search, the inertia weight function and the tabu search theory were employed to overcome the premature flaw of the basic algorithm. Then, the improved algorithm was introduced to the structural optimization of the tube- type trestle. After the setup of the optimization model, the improved algorithm was used. Optimization results and comparison with other algorithms show that the stability of improved fruit fly Optimization Algorithm is apparently improved and the efficiency is obviously remarkable. This study provides a more effective solution to structural optimization problems.

To improve the efficiency of the structural optimization design in truss calculation, an improved fruit fly optimization algorithm was proposed for truss structure optimization. The fruit fly optimization algorithm was a novel swarm intelligence algorithm. In the standard fruit fly optimization algorithm, it is difficult to solve the high-dimensional nonlinear optimization problem and easy to fall into the local optimum. To overcome the shortcomings of the basic fruit fly optimization algorithm, the immune algorithm self–non-self antigen recognition mechanism and the immune system learn–memory–forgetting knowledge processing mechanism were employed. The improved algorithm was introduced to the structural optimization. Optimization results and comparison with other algorithms show that the stability of improved fruit fly optimization algorithm is apparently improved and the efficiency is obviously remarkable. This study provides a more effective solution to structural optimization problems.

To solve the problems of multi-objective control, objective quantification difficulties and computational complexity existing in the construction management, the construction system reliability was introduced into the project management. The process of construction project was divided into several units of work based on system decomposition theory. And the reliability of each unit of work was calculated. Then, the system reliability was optimized by the improved firefly algorithm. To avoid that the basic algorithm is highly depended on the initial solution and easy to fall into local optimum at later stage, the dynamic population firefly algorithm was proposed. Engineering practice shows that the improved algorithm has higher convergence speed and accuracy of optimization. The study provides a novel method for effective construction management.

With the increase in system complexity, the intelligent heuristic optimization methods have received more and more attention on system reliability analysis. However, the objective functions and constraint conditions of system reliability are nonlinear. Thereby, a hybrid optimization method was proposed, based on the shuffled frog leaping algorithm and bacterial foraging algorithm, to solve the problem of system reliability and redundancy allocation. First, random grouping strategy was added to maintain the diversity of the population. Then, the Levy flight update strategy was used to increase the global search ability. Finally, the method of migration operation was introduced to escape from local optimums. The proposed methodology, a new version of the SFLA algorithm, was then applied to the mathematical test and the operation of the system reliability model, respectively. Results show that compared to the common methods, it can obtain the best solution, with the maximum value of the system reliability.

With the rapid development of the national economy of China, an increasing need for transportation facilities is becoming a serious challenge that the existing traffic system has to meet. Thus, the highway transportation capacity development level assessment has important significance in theory and in practice. In order to overcome the current defects of stronger subjectivity and experience in common assessment methods, the entropy weight and the TOPSIS method were introduced and employed to the comprehensive assessment of highway transportation capacity development. Shannon information entropy was applied to determine the weight value of each index in the comprehensive assessment model. After determining the index weight, the result of comprehensive assessment was obtained through the TOPSIS method. Finally, the effectiveness and feasibility of the proposed method were shown by application in practice.

Ant colony algorithm is widely used in recent years as a heuristic algorithm. It provides a new way to solve complicated combinatorial optimization problems. Having been enlightened by the behavior of ant colony's searching for food, positive feedback construction and distributed computing combined with certain heuristics are adopted in the algorithm, which makes it easier to find better solution. This paper introduces a series of ant colony algorithm and its improved algorithm of the basic principle, and discusses the ant colony algorithm application situation. Finally, several problems existing in the research and the development prospect of ACO are reviewed.

Prestressed Concrete Cylinder Pipe (PCCP) is a kind of high quality composite pipe, whose mechanical behavior is not uniform because of its complicated structure and work condition. The mechanical model is established in PCCP working stage, based on the elastic plane strain theory of axisymmetric multilayer cylinders and the mechanism of the ring-like strands action. Then the design method of prestress is put forward according to the crack control. The stress is analyzed with finite-element analysis in the condition of different hydraulic pressures, and also the method is amended compared with the finite-element analysis. It is indicated that the design method of prestress is reasonable compared with both domestic and international specifications.

Much work has been done on the optimization of the discrete variable structure design. In order to handle the optimization problem effectively, the related theories, methods, and other beneficial results were summarized. On the basis of analyzing the predecessors' research, the development direction was introduced. Then, some practical methods, including their improvements, for discrete structural optimization were analyzed. Finally, the Ant Colony Optimization algorithms were shown as promising methods. This work has significance in theory and practice for the development of structural optimization.

According to the size of the projector function to evaluate the merits of the program, Projection Pursuit method is applied to real estate investment decision-making by using the real coding based on Accelerating Genetic Algorithm (RAGA) to optimize the Projection Pursuit Classification (PPC) process and a wide range of indicators value was projected linearly. The results are reasonable and verified with an example. At the same time, the subjective of the target weight can be avoided. It provides decision-makers with comprehensive information on all the indicators of new ideas and new methods

In order to solve the premature convergence problem of the basic Ant Colony Optimization algorithm, a promising modification with changing index was proposed. The main idea of the modification is to measure the uncertainty of the path selection and evolution by using the average information entropy self-adaptively. Simulation study and performance comparison on Traveling Salesman Problem show that the improved algorithm can converge at the global optimum with a high probability. The work provides a new approach for solving the combinatorial optimization problems, especially the NP-hard combinatorial optimization problems.

Safety assessment of offshore platforms is an urgent task. Such assessments are now focusing on the structure, maintenance, and retirement of a platform. Some methods employed have many shortcomings. For example, they cannot make the reliability adequately explicable. Therefore, a mathematical tool, the unascertained measure, was introduced. First, the basic knowledge of the unascertained sets was introduced briefly. Second, the unascertained measure was defined and credible identification was set up. The method has been introduced into the fields for safety assessment of a jacket loadout procedure. Engineering practices showed that it can complete the safety assessment systematically and scientifically without any assumption. The work should have significance in theory and practice for offshore engineering.

To find a more effective method for the assessment of sustainable urban transport development, the comprehensive assessment model of sustainable urban transport development was established based on the unascertained measure. On the basis of considering the factors influencing urban transport development, the comprehensive assessment indexes were selected, including urban economical development, transport demand, environment quality and energy consumption, and the assessment system of sustainable urban transport development was proposed. In view of different influencing factors of urban transport development, the index weight was calculated through the entropy weight coefficient method. Qualitative and quantitative analyses were conducted according to the actual condition. Then, the grade was obtained by using the credible degree recognition criterion from which the urban transport development level can be determined. Finally, a comprehensive assessment method for urban transport development was introduced. The application practice showed that the method can be used reasonably and effectively for the comprehensive assessment of urban transport development.

Sjecišta gradskih cesta predstavljaju uska grla mreže gradskih prometnica te je optimalizacija organizacije prometa na križanjima ključna da se izbjegne zastoj prometa. Nakon što su se proanalizirale karakteristike, primjenjivi uvjeti i funkcije projekta kanaliziranja križanja, predloženi su osnovni postupci zasnovani na snimanju saobraćaja, projekt kanaliziranja križanja te procjena plana kanaliziranja. Zatim je izrađen model simulacije raskrižja pomoću VISSIM-a uzimajući u obzir probleme velikog križanja u gradu. Usporedba parametara i analiza simulacije pokazuju da odgovarajuće mjere kanaliziranja na raskrižjima mogu značajno pridonijeti poboljšanju kapaciteta prometa., Urban road intersections are bottle-necks of urban road networks, and the traffic organization optimization of intersections is the crux to relieve urban traffic jam. After analysing the features, applicable conditions and functions of the intersection channelization design, the basic procedures based on traffic survey, channelization design of the intersections and assessment of channelization plan were finished. Then, the simulation model of the intersection was set up by VISSIM in consideration of problems at a large intersection in a city. Parameters comparison and simulation analysis show that proper measures of channelization at intersections can significantly improve their traffic capacity.

In order to overcome the premature convergence defect of the basic particle swarm optimization (PSO) algorithm and provide an effective method for shape and sizing optimization of truss structure, an improved PSO was proposed. The random direction method was employed to produce high-quality initial population, the fuzzy system was applied in the dynamic adaptive adjustment of parameters of the PSO, and the Metropolis criteria were used to improve the performance of PSO. Then, the improved PSO was introduced to the truss structure shape and sizing optimization design. Engineering practice and comparison with the other optimization algorithms show that the algorithm has good convergence and global searching capability. The study provides a promising algorithm for the structural optimization.

In order to seek the question of controlling goal more accurate in the multiple unit control question, the article proposed the projection pursuit (PP) controlling model which is based on the genetic algorithm (GA); And it has given the detailed algorithm and the steps. Achieve the process of seeking multiple control objectives by using PP twice. We can obtain various control targets accurately by using this method, and control each link advantageously. Finally, we can acquit a greater economic efficiency.

In order to find a more effective method of solving the problem of subjectivity and difficulty to deal with the high-dimension data in the clustering, a new method—an improved PP (Projection Pursuit) based on Ant Colony Optimization algorithm (ACO) was introduced. The ant colony optimization algorithm has the strong global optimization ability and the PP method is a powerful technique for extracting statistically significant features from high-dimension data for automatic target detection and classification. The ant colony optimization algorithm was employed to optimize the function of the projected indexes in the PP. Application results show that the method can complete the selection more objectivity and rationality with objective weight, high resolving power, and stable result.

Amortization time and rationality has been discussed a lot in real estate investment research. As the price of real estate is driven by Geometric Brown Motion (GBM), whether the mortgagors should amortize in advance has become a key issue in amortization time research. This paper presents a new method to solve the problem by using the optimal stopping time theory and option pricing theory models. We discuss the option value in amortizing decision based on this model. A simulation method is used to test this method.

In order to find an effective method to deal with the uncertainty of the risk evaluation of real estate investment, a new method based on the AHM (Analytic hierarchical model) and the fuzzy comprehensive evaluation was proposed. After the establishment of the evaluation system, the AHM was employed to determine the weight of every index, and the value of the risk was obtained by using the fuzzy set. Engineering practice and comparison with other existing methods showed the rationality of the method. This study provides a promising approach for the risk evaluation of real estate investment and has significance in theory and practice for the risk management of investment.

To overcome the shortcomings of the Fuzzy Set which is a common safety assessment measure, the unascertained measure was proposed and the credible identification was set up after the introduction of the basic knowledge of the Unascertained Sets including the essential difference between the Unascertained Sets and the Fuzzy Sets. Then, the method was introduced into the safety assessment of offshore jacket and modular loadout. Finally, engineering practice showed that the method proposed here can complete the safety assessment systematically and scientifically without any assumption. The work has significance in theory and practice for safety assessment.

To management the risk of International Project Contracting where the chance and risk are accreted and the risk is bigger than the domestic engineering, the paper sets up the comprehensive evaluation system and a model of risk assessment by using the unascertained set for evaluating the risk of the international project contracting. Finally, the practicality and feasibility of the model are illustrated by the engineering practice.

The methods of the real estate investment evaluation used today usually fail to solve the high-dimension data. To overcome this shortcoming, an improved PP model was proposed. The method evaluates the merits of the investment programs, according to the size of the projector function by using the Projection Pursuit method. The ant colony algorithm was applied to finish the global optimization. The efficiency was verified with an example.

Real estate venture capital evaluating is a complex multi-objective decision-making problem that has two remarkable characteristic: incommensurability and contradictoriness among the objectives. According to the characteristic of multi-objective decision-making, this paper has made the normative approach to the data, applying the fuzzy multi-objective decision-making method of incomplete preference information, weighting according to the relationship of the data, overcoming the shortcoming of experts' weighting subjectively, solving the problem of venture capital evaluating reasonably, and getting the more reasonable sort of the programs' quality. It can be seen from the example that the physical conception of this method is clear, the mathe-matical derivation is rigorous, the solution is simple and the reliability is high.

To find an effective method to deal with the uncertainty of the risk management of real estate investment, a new model based on the AHM (Analytic hierarchical model) and the fuzzy comprehensive evaluation was proposed. After the establishment of the index system, the AHM was employed to determine the weight of every index, and the value of the risk was obtained by using the fuzzy set. Engineering practice showed the rationality of the method. This study provides a promising approach for the risk evaluation of real estate investment and it has significance in theory and practice for the risk management of investment.