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Neural conversation generation model has attracted more and more attention in open domain conversation generation. Even though NCG-based conversation generation methods obtain promising results, they tend to generate short, generic and uninformative responses for most inputs. Moreover, training NCG models heavily relies on a large amount of quality paired dialogue corpus which tends to be expensive and difficult. In this paper, a unified Cycle-Seq2Seq model is proposed for fully data-driven Neural Conversation Generation (CS2S-NCG) in open domain. CS2S-NCG has ability to simultaneously learn the relevance of paired dialogue corpus, utilize feedback about the quality of the two generation models and reduce dependency on the amount of paired training dataset. Meanwhile, a joint learning strategy supports enhanced generation by better usage of massive unpaired dialogue corpus. An alternating Joint-EM algorithm is developed to solve this joint model. A series of experiments are conducted to evaluate CS2S-NCG on two automated metrics, as well as with human evaluation. The results demonstrate that CS2S-NCG significantly improves the relevance and diversity of generation results, compared to traditional neural conversation generation models. Furthermore, quantitative results also reveal that conversation generation quality are enhanced by leveraging unpaired dialogue corpus for not only CS2S-NCG but also traditional NCG.

The joint motion of the space manipulator and the collision between the end-effector and target may cause the attitude disturbance of the base. To minimize these two kinds of disturbances simultaneously, a pre-impact trajectory planning method for a nonredundant Free-Floating Space Manipulator (FFSM) system is proposed. Firstly, using the momentum conservation and nonholonomic characteristics, a transitional state between the initial state and the final capture state is added. This state can achieve the correct capture pose of the end-effector. Thereafter, the particle swarm optimization (PSO) algorithm is employed to optimize the transitional state and parameterized joint trajectory to minimize the base disturbance caused by joint motion and collision pulses. Finally, the proposed method is applied to a 6-DOF FFSM system. The results show that this method can realize the optimal pre-impact trajectory planning, and verify its effectiveness.

Photovoltaic inverter is difficult to operate in standalone mode without robust voltage source, which handicaps the development of renewable solar energy. If the inverter works in voltage control mode, it should balance the power flow between the resources and the loads. Utilizing limited power adjustment ability of photovoltaic arrays can improve this performance, which is effective if the assigned power of photovoltaic inverter is less than the maximum power of the arrays. However, if that premise cannot be satisfied, the PV inverter can be vulnerable to disturbance, where reasonable control and mode switch strategy are necessary in this situation. This paper will introduce the scheme of voltage-controlled photovoltaic generator that utilizes the principle of power conversion in synchronous generator. The control method in the situation that the maximum capability of photovoltaic arrays is less than the assigned power of inverter is designed. The proposed method is verified in simulation and hence the effectiveness is proved, which is practical for improving robustness and stability of microgrid integrated photovoltaic inverter.

Voltage control mode is preferable because of better bus voltage support and low reliance on communication. However, that is difficult to implement on photovoltaic inverter without robust voltage source. Meanwhile, photovoltaic arrays have some power management ability that usually neglected due to the use of MPPT, which in fact damages balanced power flow and a robust and stable grid. As a result, control of dc and ac side of photovoltaic inverter is usually separated and broken, where the dc side is usually supposed as an ideal voltage source and the corresponding relationships are neglected. This paper proposes a control scheme called photovoltaic generator for photovoltaic microgrid without robust voltage source, which imitates the principle of power conversion from mature synchronous generator theory. The scheme focuses on the active participation of solar energy in power management and voltage support. The effectiveness is verified in simulation and experiment.

To analyze the complex sympathetic inrush characteristics of HVDC and study the methods of suppression, making up the blank of Electromagnetic transient simulation software of PSCAD/EMTDC not considering the hysteresis characteristics of ferromagnetic material of transformer cores as well, a new three-phase transformer model with hysteresis characteristic for electromagnetic transients based on the PSCAD/EMTDC is presented, which derives from the ideas of the transformer model considering hysteresis characteristics in ATP-EMTP, it consists of Type96 and BCTRAN. This model adds magnetizing branch considering hysteresis characteristics based on UMEC model. It's full use of the advantages of UMEC model, without using winding turns, the core cross-sectional area, the core length, etc, and the hysteresis characteristics of transformer can be described when using experimental data obtained. The simulation results show that the model both have high simulation accuracy, and because the parameters readily available, it's easy for user to use in PSCAD/EMTDC and to promote the use of the transformer model in engineering application when considering transformers with hysteresis characteristics.

Commutation failure caused by AC system failure is most common phenomenon of AC/DC dynamic interaction. The research about the DC commutation failure simply caused by AC system failure at a certain moment may not accurately reflect the complexity of HVDC commutation failure. This paper points out that the commutation voltage amplitude and phase angle and the closing time of fault are the main factors of commutation failure time discreteness in the HVDC transmission system, from the perspective of the physical nature of valve commutation process and the commutation voltage time area. Then, theoretically analyzed the features of the three-phase fault and single phase fault occur on AC bus, the paper concludes the change regularity of line voltage amplitude and line voltage phase which after Y-Y and Y-D1 transformer along with the change of transition resistance. Finally, Using PSCAD/EMTDC, the typical bipolar 12 Pulses DC system model with detailed control system is set up. The regularity of critical transition resistance in different fault moment of two fault types is analyzed to conclude the influence factors and regularity of commutation failure time discreteness in the HVDC transmission system. The results show that the most unfavorable condition to the commutation is when the AC system fault time corresponds to the pulse triggering time of commutation valve.

This article discusses about the detection of hand gesture based on computer stereovision theory. The sheltering problem of key point in the fingers is solved effectively by using the multi-camera system method. Some constraints and several reasonable and effective algorithms of matching are used to distinguish the key points on different fingers. Because of using these methods, the matching problem of the key points is solved. Several experimental results show these algorithms are effective.