# Comparative Study of Harmony Search Algorithm and its Applications in China, Japan and Korea
## 5 Harmony Search Applications in Korea
### Engineering
#### 5.1.3 Civil  
A Modified Harmony Search (MHS) algorithm was developed by [PERSON] and [PERSON] [67] to improve the dynamic modular model in order to explain the resistance and fatigue cracking of asphalt  
Figure 5: Simplified flowchart for the MPHS system suggested [62].  
concrete mixtures. The MHS algorithm was updated with the minimum and maximum bandwidth implementations to update the HS algorithm.  
[PERSON] et al. [68] developed a hybrid algorithm consisting of Improved Firefly Algorithm (IFA) and standard HS, called IFA-HS, for optimizing cost of reinforced concrete retaining walls. Additionally, the recently built Upper Bound Strategy (UBS) was integrated into the IFA-HS (IFA-HS-UBS) to boost the statistical performance of the hybrid approach. The latter can be used to find high quality outcomes in a shorter time. The UBS method was seen to affect the IFA-HS efficiency.  
[PERSON] et al. [69] identified a concept of an Artificial Neural Networks (ANNs) to predict the stability of the armor stones based on experimental results. The HS algorithm was used in their analysis to predict ideal initial weights for testing models.  
[PERSON] et al. [70] identified a re-chlorination plant position and dosage management model for two real water networks involving maintenance to ensure adequate end-of-pipeline residual chlorine concentrations under current and potential conditions. The HS for the optimization model was used in their analysis and tested by case studies of numerous re-chlorination sites.  
There have been many studies including HS in the fields of civil engineering [71] and Water Distribution Networks (WDNs). In Ref. [72], a Hybrid Harmony Search (HyHS) algorithm including HS and a rule induction algorithm was developed for the WDNs. HyHS was contrasted to an upgraded GA, HS, and hybrid GA by combining metrics and two WDS prototypes. To optimize De Jong functions, algorithms were used. Afterwards, the New York Tunnel System's low- cost-and-robustness issue concerns were addressed with these algorithms. [PERSON] et al. [73] proposed a Non-Dominated Sorting Harmony Search Differential Evolution (NS-HS-DE) algorithm for a multi-purpose design of WDNs. The algorithm merged the global DE search schemes with HS local search capabilities to boost evolutionary algorithms' search skills. This approach was compared to other evolutionary multi-objective algorithms, (e.g., NSGA-II, SPEA2, MOEA/D, and several variants of DE and HS models of non-dominance requirements). The WDN architecture problem was tested in conjunction with algorithms for four tests of two goal functions (cost reduction and resiliency maximization). [PERSON] [74] designed an optimum model of WDNs in terms of velocity reliability and cost minimization using HS. The findings indicated that a Pareto sequence of multi-target architecture approaches was effectively used in terms of cost savings and maximization of reliability.  
In Ref. [75], HS was applied to the design of WDNs with more practical constraints (e.g., flow velocity range). HS optimization found better solutions than the mathematical linear programming method with respect to design cost and a practical viewpoint. [PERSON] and [PERSON] [76] also developed and merged two major algorithm parameters, (HMCR and PAR), with a modern fine-tuning parameter-free approach for fine tuning and regular HS algorithms. After applying this to some benchmark problems, the improved HS reached the global optimum and had improved quality results.  
In Ref. [77], a novel hybrid method combining Mine Blast Algorithm (MBA), [PERSON] et al. [78], and improved HS was proposed, naming Mine Blast Harmony Search (MBHS) for optimally solving some engineering design problems such as truss structures and WDNs. Validation of MBHS has been tested over commonly known benchmarks. The optimization results confirmed improvements of the proposed hybrid algorithm over constituent optimizers and the other reported algorithms.