Differential evolution (DE) is arguably one of the most powerful stochastic real-parameter optimization algorithms in current use. DE operates through similar computational steps as employed by a standard evolutionary algorithm (EA). However, unlike traditional EAs, the DE-variants perturb the current-generation population members with the scaled differences of randomly selected and distinct population members. Therefore, no separate probability distribution has to be used for generating the offspring. Since its inception in 1995, DE has drawn the attention of many researchers all over the world resulting in a lot of variants of the basic algorithm with improved performance. This paper presents a detailed review of the basic concepts of DE and a survey of its major variants, its application to multiobjective, constrained, large scale, and uncertain optimization problems, and the theoretical studies conducted on DE so far. Also, it provides an overview of the significant engineering applications that have benefited from the powerful nature of DE.

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Differential Evolution: A Survey of the State-of-the-Art

Having developed multiobjective optimization algorithms using evolutionary optimization methods and demonstrated their niche on various practical problems involving mostly two and three objectives, there is now a growing need for developing evolutionary multiobjective optimization (EMO) algorithms for handling many-objective (having four or more objectives) optimization problems. In this paper, we recognize a few recent efforts and discuss a number of viable directions for developing a potential EMO algorithm for solving many-objective optimization problems. Thereafter, we suggest a reference-point-based many-objective evolutionary algorithm following NSGA-II framework (we call it NSGA-III) that emphasizes population members that are nondominated, yet close to a set of supplied reference points. The proposed NSGA-III is applied to a number of many-objective test problems with three to 15 objectives and compared with two versions of a recently suggested EMO algorithm (MOEA/D). While each of the two MOEA/D methods works well on different classes of problems, the proposed NSGA-III is found to produce satisfactory results on all problems considered in this paper. This paper presents results on unconstrained problems, and the sequel paper considers constrained and other specialties in handling many-objective optimization problems.

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An Evolutionary Many-Objective Optimization Algorithm Using Reference-Point-Based Nondominated Sorting Approach, Part I: Solving Problems With Box Constraints

This paper proposes a novel population-based optimization algorithm called Sine Cosine Algorithm (SCA) for solving optimization problems. The SCA creates multiple initial random candidate solutions and requires them to fluctuate outwards or towards the best solution using a mathematical model based on sine and cosine functions. Several random and adaptive variables also are integrated to this algorithm to emphasize exploration and exploitation of the search space in different milestones of optimization. The performance of SCA is benchmarked in three test phases. Firstly, a set of well-known test cases including unimodal, multi-modal, and composite functions are employed to test exploration, exploitation, local optima avoidance, and convergence of SCA. Secondly, several performance metrics (search history, trajectory, average fitness of solutions, and the best solution during optimization) are used to qualitatively observe and confirm the performance of SCA on shifted two-dimensional test functions. Finally, the cross-section of an aircraft's wing is optimized by SCA as a real challenging case study to verify and demonstrate the performance of this algorithm in practice. The results of test functions and performance metrics prove that the algorithm proposed is able to explore different regions of a search space, avoid local optima, converge towards the global optimum, and exploit promising regions of a search space during optimization effectively. The SCA algorithm obtains a smooth shape for the airfoil with a very low drag, which demonstrates that this algorithm can highly be effective in solving real problems with constrained and unknown search spaces. Note that the source codes of the SCA algorithm are publicly available at http://www.alimirjalili.com/SCA.html .

SCA: A Sine Cosine Algorithm for solving optimization problems

Salp Swarm Algorithm

Partly due to lack of test problems, the impact of the Pareto set (PS) shapes on the performance of evolutionary algorithms has not yet attracted much attention. This paper introduces a general class of continuous multiobjective optimization test instances with arbitrary prescribed PS shapes, which could be used for studying the ability of multiobjective evolutionary algorithms for dealing with complicated PS shapes. It also proposes a new version of MOEA/D based on differential evolution (DE), i.e., MOEA/D-DE, and compares the proposed algorithm with NSGA-II with the same reproduction operators on the test instances introduced in this paper. The experimental results indicate that MOEA/D could significantly outperform NSGA-II on these test instances. It suggests that decomposition based multiobjective evolutionary algorithms are very promising in dealing with complicated PS shapes.

Multiobjective Optimization Problems With Complicated Pareto Sets, MOEA/D and NSGA-II

The utility model discloses a tunnel mills with full section cantilever entry driving machine arc of underground works and digs device, including the fuselage, the fuselage bottom is equipped with walking portion, is connected through rotary mechanism between fuselage and the walking portion, and the shovel board is connected through first cylinder in fuselage front end lower part, and second cylinder connection cutting part is passed through to fuselage front end upper end, and the cutting part front end is equipped with to mill and digs the head, mills to dig firstly to be half spherical structure, and the cutting part both sides are equipped with infrared range finder respectively, still are equipped with electric control system on the fuselage, the utility model discloses the structure principle is simple, can effectual restriction face the place ahead excavate the rock mass and to the extrusion deformation of face and the convergence deformation of face, need not carry out advance support in the condition that the country rock rank is not quite poor, practices thrift the tunnel excavation cost to and the tunnelling efficiency of improvement cantilever entry driving machine.

Tunnel mills with full section cantilever entry driving machine arc of underground works and digs device

A novel resonant optical voltage sensing scheme based on Pockels effect with less optical elements is proposed to pave the way for the miniaturization of voltage sensors in a high-voltage power grid, which can improve the voltage detection accuracy by using the multiple propagation of light in the resonator composed of Bi4Ge3O12 (BGO) crystal and reflector. Based on the multiple beam interference theory, the optical sensing model is analyzed to explore the influence of the key parameters such as the propagation loss and the resonator reflectivity on the performance of resonant optical voltage sensor. Considering the propagation loss and reflectivity, a resonator is designed to promote the limit sensitivity of the resonant optical voltage sensor. Also, based on the theoretical analysis results, we obtained that the design parameters (propagation loss <inline-formula> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> and reflectivity <inline-formula> <tex-math notation="LaTeX">${r}$ </tex-math></inline-formula>) of the resonator are, respectively, <inline-formula> <tex-math notation="LaTeX">$\mu \le0.5$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">${r} \ge0.83$ </tex-math></inline-formula>. Finally, the experimental equipment of the novel resonant optical voltage sensor is built, and the measured resonator finesse shows that the limit sensitivity of the resonant optical voltage sensor can achieve <inline-formula> <tex-math notation="LaTeX">$3.689\times 10^{-{5}}$ </tex-math></inline-formula> V. Furthermore, the experimental results of the resonant optical voltage sensor demonstrate that the resonant frequency of the resonator is linear with the applied voltage. The proposed resonant sensing scheme has the potential to lay the foundation for the miniaturization of high-precision optical voltage sensors in the future.

Design of Novel Resonant Optical Voltage Sensor Based on Pockels Effect

The utility model provides a broken rock auxiliary device of microwave and combined type cantilever entry driving machine, it includes the mounting bracket, the mounting bracket has two holes that liein same side and the setting of upper and lower interval, and it has flexible hydro -cylinder to hinge with last position hole, and it has the swing hydro -cylinder to hinge with lower position hole,the swing hydro -cylinder the opposite side with the cylinder portion of flexible hydro -cylinder is articulated, be equipped with a hinged ear on the piston rod of flexible hydro -cylinder the position department that hinged ear kept away from cylinder portion is equipped with a microwave module Compared with the prior art, the utility model provides a broken rock auxiliary device of microwavepasses through the microwave and adds hot dry rock stone fast, is showing mechanics characteristics such as reducing its loading intensity, unipolar compressive strength and tensile strength The utility model provides a combined type cantilever entry driving machine that has the broken rock auxiliary device of this microwave

Broken rock auxiliary device of microwave and combined type cantilever entry driving machine

A modulator coefficient tracking system (MCTS) with the novel four-state modulation technique is proposed to improve the stability of scale factor for resonant integrated optical gyroscope (RIOG). Firstly, we analyze the influence mechanism of integrated optical phase modulator (IOPM) coefficient on the scale factor stability of RIOG. Then, the novel four-state modulation technique is proposed to synchronously detect angular velocity information and IOPM coefficient without additional optical devices, which consists of the basic triangular modulation signal and the triangular signal for demodulating modulator coefficient. Finally, MCTS based on the novel four-state modulation technique is designed to real-timely track the modulator coefficient and adjust loop-gain to be constant for improving the scale factor stability of RIOG. The experimental results show that the tracking error of MCTS is 0.23% from −40 °C to +60 °C and the scale factor stability of RIOG is optimized to 163.37 ppm. The proposed MCTS with the novel four-state modulation technique can significantly improve the performance of RIOG, which contributes to promoting the applications of RIOGs.

Modulator Coefficient Tracking Method of Resonant Integrated Optical Gyroscope Based on Novel Four-State Modulation

The invention provides a plugging device and method for a spatial vertical karst pipe, and relates to the technical field of tunnel engineering. The technical problems that the plugging process is complex, time is long, risks in construction are increased, and the treating effect is poor are solved. The plugging device comprises a concrete delivering pipe and slurry ejection pipes; the concrete delivering pipe penetrates through the karst pipe, and a gap is formed between the karst pipe and the outer wall of the concrete delivering pipe; a slurry rapid-solidification structure is arranged on the concrete delivering pipe, slurry discharged through the slurry ejection pipes passes through the slurry rapid-solidification structure to flow to the gap between the karst pipe and the outer wall of the concrete delivering pipe to plug the gap, and solidification of the slurry can be accelerated in the mode that the contact area between flowing slurry and air is enlarged through the slurry rapid-solidification structure; when plugging is carried out, low-pressure cement slurry is injected from the slurry ejection pipes for plugging. The plugging device and method have the advantages of being high in plugging speed, short in time, easy to operate and good in plugging effect.

Hui Li

Papers

Tunnel mills with full section cantilever entry driving machine arc of underground works and digs device

Design of Novel Resonant Optical Voltage Sensor Based on Pockels Effect

Broken rock auxiliary device of microwave and combined type cantilever entry driving machine

Modulator Coefficient Tracking Method of Resonant Integrated Optical Gyroscope Based on Novel Four-State Modulation

Plugging device and method for spatial vertical karst pipe