This paper presents a robust hybrid improved dolphin echolocation and ant colony optimization algorithm (IDEACO) for optimization of truss structures with discrete sizing variables. The dolphin echolocation (DE) is inspired by the navigation and hunting behavior of dolphins. An improved version of dolphin echolocation (IDE), as the main engine, is proposed and uses the positive attributes of an...

Simplified Dolphin Echolocation (SDE) optimization is an improved version of the Dolphin Echolocation optimization. The dolphin echolocation (DE) is a recently proposed metaheuristic algorithm, which was imitated dolphin’s hunting process. The global or near global optimum solution modeled as dolphin’s bait, dolphins send sound in different directions to discover the best bait among their searc...

In dolphins, natural selection has developed unihemispheric sleep where alternating hemispheres of their brain stay awake. This allows dolphins to maintain consciousness in response to respiratory demands of the ocean. Unihemispheric sleep may also allow dolphins to maintain vigilant states over long periods of time. Because of the relatively poor visibility in the ocean, dolphins use echolocat...

Simplified Dolphin Echolocation (SDE) optimization is an improved version of the Dolphin Echolocation optimization. The dolphin echolocation (DE) is a recently proposed metaheuristic algorithm, which was imitated dolphin’s hunting process. The global or near global optimum solution modeled as dolphin’s bait, dolphins send sound in different directions to discover the best bait among their searc...

The hearing and echolocation clicks of a stranded Indo-Pacific humpback dolphin (Sousa chinensis) in Zhuhai, China, were studied. This animal had been repeatedly observed in the wild before it was stranded and its age was estimated to be ~40 years. The animal's hearing was measured using a non-invasive auditory evoked potential (AEP) method. Echolocation clicks produced by the dolphin were reco...

Auditory evoked potential (AEP) responses were recorded during echolocation in an Atlantic bottlenose dolphin (Tursiops truncatus) trained to accept suction-cup EEG electrodes and detect targets by echolocation. AEP recording was triggered by the echolocation clicks of the animal. Three targets with target strengths of -34, -28 and -22 dB were used at a target distance of 2 to 6.5 m for each ta...

The target strength as a function of aspect angle were measured for four species of fish using dolphin-like and porpoise-like echolocation signals. The polar diagram of target strength values measured from an energy flux density perspective showed considerably less fluctuation with azimuth than would a pure tone pulse. Using detection range data obtained from dolphin and porpoise echolocation e...

Recent recordings of dolphin echolocation using a dense array of hydrophones suggest that the echolocation beam is dynamic and can at times consist of a single dominant peak, while at other times it consists of forward projected primary and secondary peaks with similar energy, partially overlapping in space and frequency bandwidth. The spatial separation of the peaks provides an area in front o...

A set of dolphin echolocation signals previously collected from an Atlantic bottlenose dolphin in Kaneohe Bay, Hawai’i are decomposed using a matching pursuit algorithm to further investigate the role of four types of echolocation signals outlined elsewhere [1]. The method decomposes the echolocation signals into optimal linear expansions of waveforms, which are Gabor functions defined in a dic...

Bottlenose dolphins (Tursiops truncatus) have an acute ability to use target echoes to judge attributes such as size, shape, and material composition. Most target recognition studies have focused on features associated with individual echoes as opposed to information conveyed across echo sequences (feature envelope of the multi-echo train). One feature of aspect-dependent targets is an amplitud...