In order to solve the problem that the population diversity preservation strategy only based on crowding distance of Non-dominated Sorting Genetic Algorithm-Ⅱ (NSGA-Ⅱ) cannot reflect the real crowding degree of individuals, an improved NSGA-Ⅱ algorithm based on the adaptive hybrid non-dominated individual sorting strategy (NSGA-Ⅱ ^h) was proposed. First, a novel loop-clustering individual sorting strategy was designed. Second, according to the Pareto layer-sorting information the NSGA-Ⅱ ^h algorithm adaptively chose one from the two individual sorting strategies based on classical crowding distance and loop-clustering. Finally, the diversity maintain mechanism could be improved especially during the late period of evolutionary optimization. The NSGA-Ⅱ ^h algorithm was compared with three classical algorithms including NSGA-Ⅱ, Multi-Objective Particle Swarm Optimization (MOPSO) and GDE3. The experiments on five multi-objective benchmark functions show that the NSGA-Ⅱ ^h algorithm can acquire 80% of optimal Inverted Generational Distance (IGD) values, and the corresponding two-tailed t-test results at a 0.05 level of significance are remarkable. The proposed algorithm can not only improve convergence of the original algorithm, but also enhance the distribution of Pareto optimal set.

Due to the better robustness of entangled W state, it is considered to be better qualified as information carrier for quantum information processing and quantum secure communication. Recently, many kinds of quantum direct communication protocols based on four-particle W state or three-particle asymmetric W state have been proposed. However, these protocols either have low communication efficiency or are difficult to be implemented in physics experiment. By utilizing three-particle W state and the mechanism of quantum identity authentication, a new deterministic secure quantum communication protocol was proposed. This protocol consisted of five parts: authentication code generating, quantum states preparation, quantum states distribution, eavesdropping check and identity authentication, and information communication. The two participants only needed to perform the two-particle Bell measurement, the single-particle 〖WTBX〗Z〖WTBZ〗-basis or 〖WTBX〗X〖WTBZ〗-basis measurement, and the communication efficiency was also improved: One W state can transmit one classical bit of information. The security analysis shows that the present protocol is secure against various eavesdropper Eve's attacks and impersonation attacks, so it has better security.

Remote State Preparation (RSP) is a branch of quantum information processing. In order to prepare the same state to multiple recipients, a broadcast-based RSP protocol was proposed for one sender and two receivers, and then it was extend to N receivers. GHZ states were used as shared quantum resources. By constructing two special measurement bases, the sender realized two times of multi-particle projective measurement; then the receivers used unitary operation to recover the prepared state depending on the measurement results. Analysis shows that multiparty RSP protocol can be used to broadcast information in quantum network.

Particle Swarm Optimization (PSO) algorithm is population-based and it is effective for multi-objective optimization problems. For the convergence of the swarm makes the classical algorithm easily converge to local pareto front, the convergence and diversity of the solution are not satisfactory. This paper proposed an independent dynamic inertia weights method for multi-objective particle swarm optimization (DWMOPSO). It changed each particle's inertia weight according to the evolution speed which was calculated by the value of each particle's best fitness in the history. It improved the probability to escape from the local optima. In comparison with Coello's MOPSO through five standard test functions, the solution of the new algorithm has great improvement both in the convergence to the true Pareto front and diversity.