are inspired by the social behavior of different species in
natural groups. Particle swarm optimization (PSO) [28] and
ant colony optimization (ACO) [29] are two typical swarm-
based algorithms. PSO and ACO mimic the aggregation
behavior of bird colonies and the foraging behavior of ant
colonies, respectively. Some other algorithms of this cate-
gory include: grey wolf optimizer (GWO) [30], monarch
butterfly optimization (MBO) [31], elephant herding opti-
mization (EHO) [32], moth search algorithm (MSA) [33],
manta ray foraging optimization (MRFO) [34],earthworm
optimization algorithm (EOA) [35], etc. With the devel-
opment of metaheuristics, a type of human-based meta-
heuristic algorithm is also emerging. ese algorithms are
inspired by the characteristics of human activity. Teaching-
learning-based optimization (TLBO) [36], inspired by tra-
ditional teaching methods, is a typical example of this
category among metaheuristic algorithms. Other human-
based metaheuristics include: social evolution and learning
optimization (SELO) [37], group teaching optimization
algorithm (GTOA) [38], heap-based optimizer (HBO) [39],
political optimizer (PO) [40], etc.
ere is a common feature of all these metaheuristic
algorithms that rely on exploration and exploitation in the
search space to find the optimal solution [41, 42]. Explo-
ration means that the algorithm searches for promising
regions in a wide search space and exploitation is a further
search for the best solution in the promising regions. e
balance of the two search behaviors affects the quality of the
solution. When exploration dominates, exploitation de-
clines, and vice versa. erefore, it is a big challenge to
balance exploration and exploitation for metaheuristics.
Although there are constantly new algorithms being de-
veloped, the no free lunch (NFL) [43] theory states that no
particular algorithm can solve all optimization problems
perfectly. e NFL has motivated researchers to develop
effective metaheuristic algorithms to solve various fields of
optimization problems.
In this paper, a novel swarm-based metaheuristic is
presented called tuna swarm optimization (TSO). It is in-
spired by two types of swarm foraging behavior of tunas. e
TSO is evaluated in 23 benchmark functions and 3 engi-
neering design problems. Test results reveal that the method
proposed in this paper significantly outperforms those
popular and recent metaheuristics. is paper is structured
as follows: Section 2 describes the inspiration for TSO and
builds the corresponding mathematical model. A bench-
mark function set and three engineering design problems are
employed to check the performance of TSO in Sections 3 and
4, respectively. Section 5 concludes the overall work and
provides an outlook for the future.
2. Tuna Swarm Optimization
2.1. Inspiration. Tuna, scientifically named unnini, is a
marine carnivorous fish. ere are many species of tuna, and
the size varies greatly. Tuna are top marine predators,
feeding on a variety of midwater and surface fish. Tunas are
continuous swimmers, and they have a unique and efficient
way of swimming (called fishtail shape) in which the body
stays rigid while the long, thin tail swings rapidly. Although
the single tuna swims very fast, it is still not as fast as the
nimble small fish response. erefore, the tuna will use the “
group travel “ method for predation. ey use their intel-
ligence to find and attack their prey. ese creatures have
evolved a variety of effective and intelligent foraging
strategies.
e first strategy is spiral foraging. When tuna are
feeding, they swim by forming a spiral formation to drive
their prey into shallow water where they can be attacked
more easily.
e second strategy is parabolic foraging. Each tuna
swims after the previous individual, forming a parabolic
shape to enclose its prey.
Tuna successfully forage by the above two methods. In
this paper, a new swarm-based metaheuristic optimization
algorithm, namely, tuna swarm optimization, is proposed
based on modeling these natural foraging behaviors.
2.2. Mathematical Model. In this section, the mathematical
model of the proposed algorithm is described in detail.
2.2.1. Initialization. Similar to most swarm-based meta-
heuristics, TSO starts the process of optimization by gen-
erating initial populations at random uniformly in the search
space,
X
int
i
� rand · (ub − lb)+ lb, i � 1, 2, ..., NP,
(1)
where X
int
i
is the i
th
initial individual, ub and lb are the upper
and lower boundaries of the search space, NP is the number
of tuna populations, and rand is a uniformly distributed
random vector ranging from 0 to 1.
2.2.2. Spiral Foraging. When sardines, herring, and other
small schooling fish encounter predators, the entire school of
fish forms a dense formation constantly changing the
swimming direction, making it difficult for predators to lock
a target. At this time, the tuna group chase the prey by
forming a tight spiral formation. Although most of the fish in
the school have little sense of direction, when a small group
of fish swim firmly in a certain direction, the nearby fish will
adjust their direction one after another and finally form a
large group with the same goal and start to hunt. In addition
to spiraling after their prey, schools of tuna also exchange
information with each other. Each tuna follows the previous
fish, thus enabling information sharing among neighboring
tuna. Based on the above principles, the mathematical
formula for the spiral foraging strategy is as follows:
X
t+1
i
�
α
1
· X
t
best
+ β · X
t
best
− X
t
i
+ α
2
· X
t
i
, i � 1,
α
1
· X
t
best
+ β · X
t
best
− X
t
i
+ α
2
· X
t
i− 1
, i � 2, 3, ..., NP,
⎧
⎪
⎪
⎨
⎪
⎪
⎩
(2)
α
1
� a +(1 − a) ·
t
t
max
,
(3)
2 Computational Intelligence and Neuroscience
- 1
- 2
- 3
- 4
- 5
前往页