This paper proposes a Nonlinear Model-Predictive control (NMPC) method capable of finding and converging to energy-efficient regular oscillations, which require no control action to be sustained. The approach builds u...
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ISBN:
(数字)9781665467612
ISBN:
(纸本)9781665467629
This paper proposes a Nonlinear Model-Predictive control (NMPC) method capable of finding and converging to energy-efficient regular oscillations, which require no control action to be sustained. The approach builds up on the recently developed Eigenmanifold theory, which defines the sets of line-shaped oscillations of a robot as an invariant two-dimensional submanifold of its state space. By defining the control problem as a nonlinear program (NLP), the controller is able to deal with constraints in the state and control variables and be energy-efficient not only in its final trajectory but also during the convergence phase. An initial implementation of this approach is proposed, analyzed, and tested in simulation.
To elucidate the mechanisms underlying the differences in yield formation among two parents(P1 and P2) and their F1 hybrid of cucumber, biomass production and whole source–sink dynamics were analyzed using a functio...
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To elucidate the mechanisms underlying the differences in yield formation among two parents(P1 and P2) and their F1 hybrid of cucumber, biomass production and whole source–sink dynamics were analyzed using a functional–structural plant model(FSPM) that simulates both the number and size of individual organs. Observations of plant development and organ biomass were recorded throughout the growth periods of the plants. The GreenLab Model was used to analyze the differences in fruit setting, organ expansion, biomass production and biomass allocation. The source–sink parameters were estimated from the experimental measurements. Moreover, a particle swarm optimization algorithm(PSO) was applied to analyze whether the fruit setting is related to the source–sink ratio. The results showed that the internal source–sink ratio increased in the vegetative stage and reached a peak until the first fruit setting. The high yield of hybrid F1 is the compound result of both fruit setting and the internal source–sink ratio. The optimization results also revealed that the incremental changes in fruit weight result from the increases in sink strength and proportion of plant biomass allocation for fruits. The model-aided analysis revealed that heterosis is a result of a delicate compromise between fruit setting and fruit sink strength. The organlevel model may provide a computational approach to define the target of breeding by combination with a genetic model.
Visual attention brings significant progress for Convolution Neural Networks (CNNs) in various applications. In this paper, object-based attention in human visual cortex inspires us to introduce a mechanism for modifi...
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In recent work, Akers et al. [arXiv:2306.06163] proved that the entanglement of purification Ep(A:B) is bounded below by half of the q-Rényi reflected entropy SR(q)(A:B) for all q≥2, showing that Ep(A:B)=12SR(q)...
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In recent work, Akers et al. [arXiv:2306.06163] proved that the entanglement of purification Ep(A:B) is bounded below by half of the q-Rényi reflected entropy SR(q)(A:B) for all q≥2, showing that Ep(A:B)=12SR(q)(A:B) for a class of random tensor-network states. Naturally, the authors raise the question of whether a similar bound holds at q=1. Our work answers that question in the negative by finding explicit counterexamples, which we arrive at through numerical optimization. Nevertheless, this result does not preclude the possibility that restricted sets of states, such as conformal field theory states with semiclassical gravity duals, could obey the bound in question.
An overview of the ancillary services in the Nigerian power sector is provided in this work. These services are essential in the power system because they are additional services required by the grid during critical t...
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ISBN:
(数字)9798350358834
ISBN:
(纸本)9798350358841
An overview of the ancillary services in the Nigerian power sector is provided in this work. These services are essential in the power system because they are additional services required by the grid during critical times to enable the power grid to operate in a stable, safe, and reliable manner. The ancillary services provided as stipulated in the Grid Code are black start, frequency control, operating reserves, and voltage control. The System Operator procures the relevant ancillary service depending on the requirement of the grid at a particular time. The paper further presents some ways of improving the viability of ancillary services for the energy grid of Nigeria. These include making incentives more attractive for suppliers of ancillary services, utilizing more hydroelectric power plants for generation and load balancing, integrating distributed generation to provide support to the reactive power, and making necessary investments in the grid.
Random copolymerization polypropylene (PPR), a recyclable thermoplastic material with a melting temperature of over 150°C and excellent mechanical properties, has potential to become the insulation materials used...
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ISBN:
(数字)9781728155111
ISBN:
(纸本)9781728155128
Random copolymerization polypropylene (PPR), a recyclable thermoplastic material with a melting temperature of over 150°C and excellent mechanical properties, has potential to become the insulation materials used in high voltage cables. To investigate dielectric properties of PPR and its nanocomposites at different temperatures, especially the dielectric spectrum at high temperatures, film samples of PPR and its nanocomposites doped with different content of nano silica were prepared. The microscopic morphologies were observed firstly for analyzing the dispersion of nanoparticles. Then the dielectric spectrums were measured at temperatures of 30, 50, 70, 90, 110 and 130°C. After this, the effects of nanoparticle content, temperature and frequency on the relative permittivity and dielectric dissipation factors are discussed and the mechanism is analyzed. It can be concluded that relative permittivity of PPR and its nanocomposites are almost unaffected by temperature in the range of 30 - 110°C and remains relatively low values. When the temperature is below 110°C, the relative permittivity of the PPR nanocomposites increases with the increase of temperature; And when the temperature is 110°C or above, the value is related to the applied voltage frequency and the content of nanoparticles. And with the temperature rising, the dielectric dissipation factor of PPR nanocomposites have an evident increase at lower frequency, which contributes to the DC conductivity.
The security of measurement device-independent quantum key distribution (MDI QKD) relies on a thorough characterization of one's optical source output, especially any noise in the state preparation process. Here, ...
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The security of measurement device-independent quantum key distribution (MDI QKD) relies on a thorough characterization of one's optical source output, especially any noise in the state preparation process. Here, we provide an extension of the loss-tolerant protocol [Phys. Rev. A 90, 052314 (2014)], a leading proof technique for analyzing the security of QKD, to MDI QKD protocols that employ mixed signal states. We first reframe the core of the proof technique, noting its generalization to treat d-dimensional signal encodings. Concentrating on the qubit signal state case, we find that the mixed states can be interpreted as providing Alice and Bob with a virtual shield system they can employ to reduce Eve's knowledge of the secret key. We then introduce a simple semidefinite programming method for optimizing the virtual twisting operations they can perform on the shield system to yield a higher key rate, along with an example calculation of fundamentally achievable key rates in the case of random polarization modulation error.
This paper incorporates a continuous-type network flexibility into chance constrained economic dispatch (CCED). In the proposed model, both power generations and line susceptances are continuous variables to minimize ...
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In order to find out the effect of temperature and mechanical stress on the dielectric breakdown strength of Ethylene Propylene Rubber (EPR), AC breakdown tests of EPR samples were carried out at different temperature...
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ISBN:
(数字)9781728155111
ISBN:
(纸本)9781728155128
In order to find out the effect of temperature and mechanical stress on the dielectric breakdown strength of Ethylene Propylene Rubber (EPR), AC breakdown tests of EPR samples were carried out at different temperatures and compressive stress. Two-parameter Weibull statistical distribution was used to analyze the breakdown strength. The experimental results show that the dielectric strength of EPR decreases with the increase of temperature when only temperature is applied. Under the same temperature, the breakdown strength of EPR firstly increases with the compressive stress rising, gradually reaches a maximum and finally shows a decreasing tendency. It's due to the effect of compressive stress on the intermolecular distance and thermal expansion of EPR.
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