In recent years, noise-related disputes caused by construction equipment have increased, resulting in delays and cost overruns in the construction process. To deal with this challenging issue, passive noise control methods such as soundproof barriers and enclosures have been widely used. However, these methods have a limited effect when used to attenuate low-frequency noise. This research aims to suggest a noise management model and to demonstrate the applicability of active noise control (ANC) as a new approach to supplement the limitations of passive noise control. Simulations were conducted to demonstrate and identify the noise reduction effect by active noise control for construction equipment. The simulation results show that noise cancellation can be highly efficient in the low- and mid-frequency bands below 1,000 Hz and that the reduction effect degraded as the frequency increased. On the basis of the findings presented in this research, an environmental manager will be able to mitigate noi...

Construction activities are associated with various noise-related issues, including health problems, cost overruns, and schedule delays. These issues could be averted by conducting comprehensive noise assessment and prediction during the preconstruction phase. Conventional approaches are inadequate because they focus on passive and defensive noise management initiated ex post facto. This paper presents a model that uses case-based reasoning to predict noise in the preconstruction phase. The model was validated by comparing the output of test cases and previous cases. The results show the output of the retrieved cases to be close to that of the test case, with correlation coefficient analysis indicating a high correlation between the actual and predicted outcomes. The model suggests practical alternatives to improve current noise management and converts the paradigm of construction noise management from ex post facto measures to preventive measures in the preconstruction phase.

Construction projects require huge amounts of capital and have many risk factors due to the unique industry characteristics. For a project to be successful, accurate cost estimation during the design phase is very important. Thus, this research aims to develop a cost estimation model where a modification method integrates influential factors with significant parameters. This study identified a modified parameter‐making process, which integrates many influential factors into a small number of significant parameters. The proposed model estimates the cost using quantity‐based modified parameters multiplied by their price. A case study was conducted with 24‐residence building project, and the estimation accuracy of the suggested method and a CBR model were compared. The proposed model achieved higher overall cost‐estimation accuracy and stability. A large number of influence factors can be modified as simple representatives and overcome the limitations of a conventional cost estimation model. The paper originality relates to providing a modified parameter‐making process to enhance reliability of a cost estimation. In addition, the suggested cost model can actively respond to the iterative requirements of recalculation of the cost.