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Duo, Zhang Guang,Mu, Wu Jin 대한전자공학회 1992 HICEC:Harbin International Conference on Electroni Vol.1 No.1
This paper implements efficiently the problem of Mechanical Theorem Proving (MTP) in propositional logic according to the Davis & Putnam Rules. Through applying strategies, such as deleting, decomposing, merging and removing sequentially all the atoms and their negations, we can abandon all the used sets of ground clauses, and put forword the refutation procedure determinately step by step. And the conclusion can be obtained within at most m steps. (Here m indicates the number of the atoms in s0, the initial set of ground clauses.) Compared with all the past classical methods in solving the problem of MTP, the method provided by this paper has several advantages: simple, convenient, determinate and highly efficient; and it requires only a lower_level support of environment, for using non_intelligent languages, BASIC for example, may implement the problem of MTP simply and efficiently.
Yue Zhang,Duo Yao,Huan Huang,Min Zhang,Lina Sun,Lin Su,LiHua Zhao,Yueying Guo,Ye Jin 한국축산식품학회 2023 한국축산식품학회지 Vol.43 No.5
This experiment aims to investigate the impact of probiotic feed on growth performance, carcass traits, plasma lipid biochemical parameters, intramuscular fat and triglyceride content, fatty acid composition, mRNA expression levels of genes related to lipid metabolism, and the activity of the enzyme in Sunit sheep. In this experiment, 12 of 96 randomly selected Sunit sheep were assigned to receive the basic diet or the basic diet supplemented with probiotics. The results showed that supplementation with probiotics significantly increased the loin eye area, and decreased plasma triglycerides and free fatty acids, increasing the content of intramuscular fat and triglycerides in the muscle and improving the composition of the fatty acids. The inclusion of probiotics in the diet reduced the expression of adenosine 5’-monophosphate-activated protein kinase alpha 2 (AMPKα2) mRNA and carnitine palmitoyltransferase 1B (CPT1B) mRNA, while increasing the expression of acetyl-CoA carboxylase alpha (ACCα) mRNA, sterol regulatory elementbinding protein-1c (SREBP-1c) mRNA, fatty acid synthase mRNA, and stearoyl-CoA desaturase 1 mRNA. The results of this study indicate that supplementation with probiotics can regulate fat deposition and improves the composition of fatty acids in Sunit sheep through the signaling pathways AMPK-ACC-CPT1B and AMPK-SREBP-1c. This regulatory mechanism leads to an increase in intramuscular fat content, a restructuring of muscle composition of the fatty acids, and an enhancement of the nutritional value of meat. These findings contribute to a better understanding of the food science of animal resources and provide valuable references for the production of meat of higher nutritional value.
Simplified model prediction current control strategy for permanent magnet synchronous motor
Zhang, Housheng,Zhu, Shengjie,Jiang, Junjie,Wang, Qingzhuang,Wang, Ao,Jin, Duo The Korean Institute of Power Electronics 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.11
A simplified model predictive current control strategy based on mathematical auxiliary line method is proposed to increase the permanent magnet synchronous motor (PMSM) predictive current control system's steady-state performance while reducing the system's computational complexity. The mathematical models of current prediction, first-order compensation, and cost function are presented by analyzing the prediction current control strategy of the conventional models. Within a control cycle, the simplified model predictive current control algorithm applies two voltage vectors and omits the error calculation of cost function. The anticipated voltage of transformer obtained from the beat-free current control standard is considered the reference voltage, and the judgment of the area, where the reference voltage vector is found and the strategy for double voltage vector is selected, is put forward. The optimal voltage vector can be directly output without the error calculation of the cost function in the method, thereby effectively reducing the computation load and complexity of the system and improving the steady-state performance. Experimental results verify the validity and accuracy of the proposed simplified model of predictive current control strategy for PMSM control.
Two‑vector predictive current control strategy based on maximum torque per ampere control for PMSMs
Duo Jin,Housheng Zhang,Shengjie Zhu,Ao Wang,Junjie Jiang 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.8
In permanent magnet synchronous motor systems with double closed-loop maximum torque current ratio control, a PI adjuster is used as the current inner ring. Unfortunately, the current may not be tracked effectively due to controller saturation when the load suddenly changes. To counteract this effect, a novel two-vector predictive current control strategy based on maximum torque current ratio control is proposed in this paper. The control strategy introduces the model predictive current control of two voltage vectors based on maximum torque per ampere control, which is acted upon by two voltage vectors in one control period. The second selected vector is no longer limited to the null vector. The orientation and amplitude of the synthesized virtual voltage vector are adjustable. Simulation results indicate that the proposed control method has the advantages of maximum torque per ampere control and model predictive control. It optimizes the stability of the system and reduces the fluctuation of the stator current.
Mechanical Behavior of Composite Beams Considering Nonlinear Shear Stiffness of Clustered Studs
Duo Liu,Ding Zhou,Bohai Ji,Wenqin Deng,Shang Zha,Jiandong Zhang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.4
Clustered studs are suitable for use in prefabricated steel-concrete composite beams. As a kind of shear connector, clustered studs have a non-negligible influence on the mechanical behavior of structures. Based on the theory of elasticity, prefabricated composite beams investigated via laminated plane stress problem. The load-slip curves of the shear connectors are linearly processed, and through iterative calculations, the displacement and stress distribution functions of prefabricated composite beams are obtained. Then, a model test is carried out on the positive bending moment section of prefabricated composite beams. A sampling method with front segments controlled by the load and back segments controlled by the slip is adopted. This method provides a better rate of convergence and higher accuracy than those of other methods. The test results show that when the load is small and the composite beam is in the elastic stage, the slope of the load-slip curve can be used as the shear stiffness of the clustered studs. When the load is large and the composite beam enters the plastic stage, the nonlinear shear stiffness of the studs must be considered to obtain a high-precision solution.
Direct bandgap type-I Ge quantum dots/GeSnSi for SWIR and MWIR lasers
Liyao Zhang,Peng Yu,Shuang Yao,Duo Feng,Jinmeng Dai 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.1
A direct bandgap type-I Ge QDs/Ge1−y−zSnySiz double-heterostructure on Ge1−xSnx virtual substrates is proposed for SWIRand MWIR lasers. The Ge1−y−zSnySiz barrier is lattice-matched to Ge1−xSnx. The band structures are calculated with differentto Sn contents in Ge1−y−zSnySiz and Ge1−xSnx. The band edge energies of Ge QDs vary linearly with x, and independent withy. The Γ-valley is below L-valley when x exceeds 7.5%. The ground states of electrons of Γ- and L-conduction band varieswith both x and y. High x and y can increase the conduction band offsets and decrease the valence band offsets. Emissionwavelengths range from 1.91 to 4.6 μm are achieved from the proposed structure with proper Sn contents.
Unified coordinated control strategy for two parallel inverters TPOW‑PMSM system
Housheng Zhang,Shengjie Zhu,Duo Jin,Ao Wang,Junjie Jiang,Lanlan Yu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.2
The three-phase open-winding permanent magnet synchronous motor (TPOW-PMSM) is generally used to drive electric vehicles. The voltage vector spatial distribution and fault-tolerant topological structure of a TPOW-PMSM system with two parallel inverters are analyzed in this paper. Then, based on the unified PWM modulation algorithm, a unified coordinated control strategy based on reference voltage vector 120º decoupling control is proposed. The speed and current double closedloop control systems of two parallel inverters are designed, and a PI + repetitive controller of the speed loop is designed to realize fast and stable speed control. The realization process does not require sector judgment or table lookup calculations, and the switching time of each bridge arm switch tube is determined by the instantaneous value of the three-phase voltage of the two parallel inverters, which simplifies the control algorithm. Experimental results show that the unified coordinated control strategy with the PI + repetitive controller can control the normal operation of a TPOW-PMSM, and realize smooth and reliable transitions from the normal operation state to the fault-tolerant operation state. The proposed unified coordinated control strategy with the PI + repetitive controller effectively suppresses the instantaneous value of system zero-sequence current, and inhibits the influence of the dead zone effect.