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FP-Growth algorithm is an association rule mining algorithm based on frequent pattern tree (FP-Tree), which doesn’t need to generate a large number of candidate sets. However, constructing FP-Tree requires two scansof the original transaction database and the recursive mining of FP-Tree to generate frequent itemsets. In addition, the algorithm can’t work effectively when the dataset is dense. To solve the problems of large memory usage and low time-effectiveness of data mining in this algorithm, this paper proposes an improved algorithm based on adjacency table using a hash table to store adjacency table, which considerably saves the finding time. The experimental results show that the improved algorithm has good performance especially for mining frequent itemsets in dense data sets.

This paper introduces the design of semi-passive RFID tag chip capable of monitoring container safety. A system framework complying with requirements by ISO/IEC 18000-6C is firstly presented, and then differences from the key units of common passive chip, such as switch-state monitoring circuit, power management unit and anti-shake design in baseband processor, are elaborated. The main function of such a chip is to record the container opening frequency during transportation. Finally, the realizations of each unit’s function are simulated.

This article is to explore the effect of conditions of reinforced concrete on chloride ion penetration. The influence of the crack width and the thickness of protective layer were studied. In consideration of the randomness of concrete crack width and the fuzziness of its effect on durability, the fuzzy reliability index calculation method was adopted in this paper to calculate the reliability of crack control criterion. Different thicknesses of protective layer of reinforced concrete specimens were designed, and cracks of reinforced concrete specimens were formed by embedding steel sheet. Then specimens were soaked in chloride solution. Finally, the content of chloride ion in concrete was determined by sampling. The results showed that cracks significantly increased diffusion speed of chloride ion within a certain region and the influence degree increased with the increase of crack width. And the influence of concrete cover thickness and concrete strength level on βw was not significant.