Although the need for an integration of engineering tasks has been stressed for a long time, the success that we see in this regard is very limited. We believe that there is justified hope for object oriented concepts...
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ISBN:
(纸本)0872629155
Although the need for an integration of engineering tasks has been stressed for a long time, the success that we see in this regard is very limited. We believe that there is justified hope for object oriented concepts to really provide the basis for considerable progress in the integration of the engineering workflow. The construction industry primarily views itself as users of application software. This software, however, ought to be task specific. A translation of the physical problems dealing with real (highly complex) objects as viewed by the engineer into abstract, 'computer-digestable' (less complex) representations should not be necessary. Some tasks, for instance critical or confidential ones, we will have to solve ourselves. We hop that an object-oriented approach will enable us to produce and use tools that are highly flexible, specifically for mapping complex objects like engineering structures. It can no longer be justified to write - or to have written - code that is only usable for a very specific task and that has to be thrown away completely when this task is replaced or changes substantially. Practical experiences with object-oriented concepts will be reported for an interface between CAD-applications and databases.
The functional design criteria and other technical requirements are to be established during the pre-design planning stage of a project. At this pre-design stage, the formulation of the problem is imprecise and incomp...
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ISBN:
(纸本)0872629155
The functional design criteria and other technical requirements are to be established during the pre-design planning stage of a project. At this pre-design stage, the formulation of the problem is imprecise and incomplete. However, since it is establishing major project planning decisions, it will impact scope, operation, and cost of the construction project. Intelligent Project Development Brochure (IPDB) system simplifies the process of project development by helping users identify their needs and requirements, and convert them into functional criteria. This system improves early programming, planning and design decisions required by the Army's project development process. This can also be used to develop realistic, cost-effective facilities that meet the organizational and physical development requirements of the using service and conform to the Army regulations and DOD construction criteria.
Theoretically, it may be assumed that with proper construction and maintenance the life of a building could be extended almost indefinitely. In practice, however, buildings tend to have a finite lifespan. The performa...
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ISBN:
(纸本)0872629155
Theoretically, it may be assumed that with proper construction and maintenance the life of a building could be extended almost indefinitely. In practice, however, buildings tend to have a finite lifespan. The performance of the building in relation to functional use to meet current needs often determines the usability of the building. Objective measurement of functional performance in a building is a very complex issue. Although some functional attributes can be expressed in quantitative terms, it is not possible or practical to express all functional attributes such as safety, security, convenience etc. in quantitative terms. In this paper, the development of a PC-based computer model to assist in the measurement of functional performance of a building is discussed. Buildings possess complex sets of attributes and most of the attributes are interdependent. Measurement of the functional condition of a building includes comprehensive evaluation of the attributes in relation to each other.
The environmental impact assessment of projects is one of the most common and complex environmental evaluation tasks. The diversity and depth of expertise required for pose major difficulties for the development of co...
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ISBN:
(纸本)0872629155
The environmental impact assessment of projects is one of the most common and complex environmental evaluation tasks. The diversity and depth of expertise required for pose major difficulties for the development of computer systems that can help the process. Knowledge-based systems offer a potential solution by providing ways to represent some evaluation heuristics and to reason with the qualitative and quantitative information involved. However, knowledge acquisition is a major bottleneck in expert system development, especially in problems with a weak domain theory such as environmental evaluation. This paper presents EELS, an environmental evaluation learning apprentice system, which can partly overcome this difficulty by acquiring and improving evaluation heuristics through its normal use. Environmental impact estimation and comparison rules are acquired through an inductive process that classifies impact levels by extracting important commonalities and differences between previous impact assessments stored in a database. The induced rules are generalizations of the past assessments, which can be used for impact assessment predictions in situation not previously encountered by EELS.
In many countries, contracts based on bill of quantities are very common in construction industry. Although estimating and tendering are overwhelmed by uncertainties, the common practice is still dominated by the dete...
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ISBN:
(纸本)0872629155
In many countries, contracts based on bill of quantities are very common in construction industry. Although estimating and tendering are overwhelmed by uncertainties, the common practice is still dominated by the deterministic approaches. A stochastic cost engineering system for estimating and tendering for measured construction projects is described in some details. It is preceded by an overall description of project estimating and tendering environment which emphasizes the importance of the system. A brief description of the system objectives is stated. Sample project files are given for illustration. The system is implemented in the Windows environment using the Microsoft Excel spreadsheet. Discussion of the system is followed by statement of the important conclusions.
In many countries, contracts based on bill of quantities are very common in construction industry. Although estimating and tendering are overwhelmed by uncertainties, the common practice is still dominated by, the det...
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ISBN:
(纸本)0872629155
In many countries, contracts based on bill of quantities are very common in construction industry. Although estimating and tendering are overwhelmed by uncertainties, the common practice is still dominated by, the deterministic approaches. A stochastic cost engineering system for estimating and tendering for measured construction projects is described in some details. It is preceded by an overall description of project estimating and tendering environment which emphasizes the importance of the system. A brief description of the system objectives is stared. Sample project files are given for illustration. The system is implemented in the Windows environment using the Microsoft Excel spreadsheet. Discussion of the system is followed by statement of the important conclusions.
The trial load method is still an important method for the stress analysis of arch dams at present. However, the trial load method can be used only for the linear elastic analysis of arch dams, the result from this me...
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ISBN:
(纸本)0872629155
The trial load method is still an important method for the stress analysis of arch dams at present. However, the trial load method can be used only for the linear elastic analysis of arch dams, the result from this method is only an approximate solution of the actual ones. The constitutive relation of arch dam's material is nonlinear, hence it is necessary to discuss nonlinear trial load method of arch dams. In addition, quite a few arch dams with peripheral joint have been constructed around the world, for the relative displacements between arch dam's body and boundary bearer, the stress analysis of arch dams with peripheral joint is nonlinear too, so that, the trial load method of arch dams with peripheral joint is needed to make further study. This paper presents a nonlinear trial load method which can be used to calculate the limit of bearing capacity (including overload factor and strength reserve coefficient) and trace the procedure of collapse for conventional arch dams or arch dams with peripheral joint. According to the mathematic-mechanic model presented in this paper, the program was developed which has been used for the analysis of Lijia Gorge arch dam and Baiyun River arch dam with peripheral joint, the results are reasonable.
A typical building engineering process involves multiple project participants and several computer applications. These participants and applications have their own views of the underlying building data Since these use...
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ISBN:
(纸本)0872629155
A typical building engineering process involves multiple project participants and several computer applications. These participants and applications have their own views of the underlying building data Since these users (i.e., participants and applications) contribute to and draw from the same overlapping set of data. the problem here is to partition the set of building data into logical fragments that meet two major requirements: (1) supporting those multiple views and (2) still being meaningful to the domain. I call this problem the data partitioning problem. It is analogous to the vertical fragmentation problem in distributed database design, for which algorithms using matrix manipulation were proposed (Ozsu, 91). The limitations of these algorithms are that they address only the first requirement and are computationally expensive. In this paper, I propose constraint satisfaction neural networks that handle both requirements in solving the problem. The user, in this case, is the designer of the database supporting those participants and computer applications. As a conclusion, a database designer can use these neural networks as effective assistant tools to partition building data in support of multiple views or data uses. In each problem occurrence. these networks yield a high probability of finding the best solution. Moreover, the designer has direct control over the way in which each network goes about solving the problem. This capability comes from a number of parameters whose value can be specified by the designer. By changing the ratio of their values, the designer can define a set of prioritized criteria and can watch the solution that the network comes up with each time. Each solution comes with a measure of how well it satisfies the problem constraints according to the given criteria. The designer can compare all these solutions based on their measure and can then make a conscientious decision about which solution to use.
A technique has been presented for calculating longshore wave energy flux which can be used in areas where offshore wave data are available and the offshore bottom contours are nearly straight and parallel. This metho...
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Limitations of the Morison equation for computing wave forces on small submerged structures have encouraged the use of dimensionless relationships containing only height, period and water depth. However in dividing th...
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