فصلنامه فناوری آموزش
پیاپی 1 (زمستان 1385)

As we can see in many bridges in the country, due to the lack of implementation of the bridge maintenance management system, the range of failures is gradually It has expanded and led to declining resistance and increasing the vulnerability of bridges. Due to the hot and humid weather conditions and the presence of salts in it The Persian Gulf region has seen signs of failure, including numerous cracks and local damage, in many of the concrete slabs in the area's structures and bridges. It is possible. Therefore, the assessment of the condition of concrete slabs prevents the progress of failure, removal from service and repair of structures.In this paper, the Expert-Slab Bridge expert system is presented to assess the failure of concrete slabs. Expert system, computer program   It is intelligence that uses the knowledge and methods of inference and inference to solve problems. This system includes an interpreter, an inference method Knowledge-based and database. Bridge deck failures due to environmental conditions and cracked concrete structures, failures Surface and instrumental failures have been evaluatedSeveral case studies and comparisons between technical inspection results and the expert system In order to gain reliability and accuracy, the results of the system have been done. System outcomes include a concrete bridge slab identification, inference Expert system with failures and their causes, status index, status description, suggested solution for repair and diagram of useful life of concrete slab Is .

This paper is the result of laboratory work performed on the initial and final setting times of high-strength concrete with different percentages of microsilica. The penetration resistance method (ASTM C 403) has been used to determine the setting times of concrete. In this method, first the concrete is made and then the coarse grades of the four large aggregates are separated using a sieve. It is important to know the timing of concreting in the planning of its executive operations. In fact, this feature of concrete is effective in determining the allowable time of transport, casting, vibration and surface polishing of concrete. The results of the initial setting time test are also used to find the starting point for spontaneous shrinkage of concrete, which accounts for the largest amount of shrinkage in highly resistant concretes. The results of this study show that with increasing microsilica percentage, the initial and final bonding times of concrete increase.

In the present paper, using evolutionary strategy, optimization of problems with continuous variables is performed. Evolutionary strategy is one of the meta-exploration methods that is basically provided for problems with continuous variables and can adjust its parameters during the optimization process. In order to evaluate, optimization of known functions is performed using evolutionary strategy and finally the results are presented and the effect of different parameters on the optimization process is presented by presenting tables and graphs. And the results obtained from the presented method are compared with the results obtained from other methods.

Today, urban parks are an integral part of biological complexes and public spaces, especially in metropolitan areas, and play an essential role in meeting the social and individual needs of citizens. These spaces occupy a large part of people's daily time and environment, including children, and therefore the upgrading and enrichment of these spaces can be effective in personal growth, social interactions, strengthening the sense of cooperation and even educating citizens and children. Be. Due to the special characteristics of children's growth, health and safety, a part of the function of urban open spaces, including parks, is always allocated to children. Therefore, the preparation of urban open spaces, including parks, is of particular importance for children as citizens and future builders of the city. In this article, relying on the unique characteristics of children, as an important part of citizens, the necessity and importance of using the capacity of urban parks to grow their creativity is emphasized and in this regard, some of the principles and criteria of garden design Urban landscapes are presented in proportion to the rainfall and flourishing of children's creativity. Their participation in the design process of children's parks and play spaces is also suggested as one of the active and dynamic design strategies. In this regard, based on the research method of content analysis, some studies of children's creative development and the process of designing open spaces and urban parks have been studied and it is concluded that children's direct participation in creating their space, in addition to creating more desire to attend and interact. In the environment, the possibility of physical, mental, social development, talents and their creativity is also provided.

Wrong ways of implementing traditional buildings, especially rural ones, which are due to the lack of use of quality materials, lack of knowledge of the principles of execution andThe technical details are the cause of the most catastrophic accidents from the not-so-terrible earthquakes, but with a lot of financial losses, especially casualties.Is.Teaching the technical performance of a traditional building is essential, as it will significantly increase the useful life of the building, as well asIt is resistant to earthquakes.In this article, with an approach to building and indigenous materials and teaching how to build these buildings in the country's villages and the methods of building brick buildings to itIt has been discussed that: Reinforcement of the ground under the foundation, basic foundations, seat making and bitumen execution with a special execution method inThey are resistant to earthquake movements and also from brick wall constructions, along with skeletal restraint byThe backrests are listed in the view. In the next article, which is a continuation of this research, cases such as: covering the horseshoe with detailed detailsTechnical and rigid connection. Vertical and horizontal windings will be mentioned simultaneously and the roof covering in the structure. Hopefully withThe guidelines and tutorials discussed in this discussion are traditional brick buildings (which are also the national capital of the country) within the framework.Build the mentioned foundations.

Strain reversal in the inelastic range may cause a dramatic drop in the tangent modulus for mild steel struts. Other material properties also affect the tangent modulus. Consequently the influence of several of these properties is examined for an electric-resistance welded steel tube. The variables chosen are: (1) Strain hardening caused by varying the amount of tensile prestrain; (2) strain aging; (3) and the Bauschinger effect, for a specific steel type. The results of 39 stub column tests on semi-killed steel specimens show that tensile prestrain reduces the tangent modulus compared with that found for the as-received tube, but strain aging is seen to be significant in reducing this loss in value. The variations obtained for the tangent modulus are illustrated. The variations are given as functions of the amount of tensile prestrain and whether the steel is fully aged or non-aged. The importance of knowledge of prior strain history of a material is highlighted.

In this paper, in order to modify and improve the handoff process, which contains initiation and execution phases, three new prioritization schemes have been investigated. These new schemes prioritize handoff requests considering both traffic and propagation conditions. According to suggested schemes, priority of different candidate base-stations is based on three measurements in a joint state. These measurements are received power at mobile unit, power variation rates, and the number of free traffic channels of adjacent base-stations. Simulation results show that considering similar conditions, i.e. equal number of handoffs, lower call dropping (outage) and smaller delay distance will be achieved by new prioritization schemes rather than previous works. It means access to lower forced termination probability and interference and hence better QoS (Quality of Service). Finally, due to the best trade offs between propagation and traffic criteria, simulation results introduce SPBPS3 as optimum scheme.