Bi-level Mixed-Integer Nonlinear Optimization for Pelagic Island Microgrid Group Energy Management Considering Uncertainty

To realize the safe, economical and low-carbon operation of the pelagic island microgrid group, this paper develops a bi-level energy management framework in a joint energy-reserve market where the microgrid group (MG) operator and renewable and storage aggregators (RSA) are independent stakeholders with their own interests. In the upper level, MG operator determines the optimal transaction prices with aggregators to minimize MG operation cost while ensuring all safety constraints are satisfied under uncertainty. In the lower level, aggregators utilize vessels for batteries swapping and transmission among islands in addition to energy arbitrage by participating in energy and reserve market to maximize their own revenue. An upper bound tightening iterative algorithm is proposed for the formulated problem with nonlinear terms and integer variables in the lower level to improve the efficiency and reduce the gap between upper bound and lower bound compared with existing reformulation and decomposition algorithm. Case studies validate the effectiveness of the proposed approach and demonstrate its advantage of the proposed approach in terms of optimality and computation efficiency, compared with other methods.Comment: Accepted by CSEE Journal of Power and Energy System

Networked Multiagent Safe Reinforcement Learning for Low-carbon Demand Management in Distribution Network

This paper proposes a multiagent based bi-level operation framework for the low-carbon demand management in distribution networks considering the carbon emission allowance on the demand side. In the upper level, the aggregate load agents optimize the control signals for various types of loads to maximize the profits; in the lower level, the distribution network operator makes optimal dispatching decisions to minimize the operational costs and calculates the distribution locational marginal price and carbon intensity. The distributed flexible load agent has only incomplete information of the distribution network and cooperates with other agents using networked communication. Finally, the problem is formulated into a networked multi-agent constrained Markov decision process, which is solved using a safe reinforcement learning algorithm called consensus multi-agent constrained policy optimization considering the carbon emission allowance for each agent. Case studies with the IEEE 33-bus and 123-bus distribution network systems demonstrate the effectiveness of the proposed approach, in terms of satisfying the carbon emission constraint on demand side, ensuring the safe operation of the distribution network and preserving privacy of both sides.Comment: Submitted to IEEE Transactions on Sustainable Energ

A comparative study of the proventricular structure in twenty Chinese Tettigoniidae (Orthoptera) species

This study focuses on the proventriculus and the alimentary canal of twenty Tettigoniidae species among three subfamilies, Tettigoniinae, Phaneropterinae and Conocephalinae. Each part of the alimentary canal and the inner structure of proventriculus were examined under optic microscope and scanning electron microscopy. As a result, the length of each part of the alimentary canal and the inner structure of proventriculus were highly associated with feeding habits. Carnivorous species always had a short foregut and long cilia on the base of the sclerotized appendix in proventriculus, whereas herbivorous species always had a longer foregut and a highly sclerotized proventriculus. These results increase understanding of the alimentary canal in Tettigoniidae and will be useful in future studies of their feeding habits

Strategic Analysis of Dual Sourcing and Dual Channel with an Unreliable Alternative Supplier

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148383/1/poms12938_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148383/2/poms12938.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148383/3/poms12938-sup-0001-AppendixS1.pd

Target-driven sustainable product development

Figuring in sustainability in product development requires a profound understanding of the cause and effect of engineering decisions along the full spectrum of the product lifecycle and the triple bottomline of sustainability. Sustainability design targets can contribute to mitigating the complexity involved, by means of a formalised problem description. This article discusses how sustainability design targets can be defined and presents methods for systematically implementing these targets into the design process. To that end, different means of decision support mechanisms are presented. They comprise (a) use cases of target breakdowns in subsystems, (b) systematic reduction of solution space and (c) assistance in design activities to ensure achievement of sustainability design targets. This paper explains how interfaces to engineering tools such as Computer Aided Design/Engineering (CAD/CAE) or Product Data/Lifecycle Management (PDM/PLM) can be put in place to make the process of retrieving information and providing decision support more seamless

Quantifying Reproducibility in Computational Biology: The Case of the Tuberculosis Drugome

How easy is it to reproduce the results found in a typical computational biology paper? Either through experience or intuition the reader will already know that the answer is with difficulty or not at all. In this paper we attempt to quantify this difficulty by reproducing a previously published paper for different classes of users (ranging from users with little expertise to domain experts) and suggest ways in which the situation might be improved. Quantification is achieved by estimating the time required to reproduce each of the steps in the method described in the original paper and make them part of an explicit workflow that reproduces the original results. Reproducing the method took several months of effort, and required using new versions and new software that posed challenges to reconstructing and validating the results. The quantification leads to “reproducibility maps” that reveal that novice researchers would only be able to reproduce a few of the steps in the method, and that only expert researchers with advance knowledge of the domain would be able to reproduce the method in its entirety. The workflow itself is published as an online resource together with supporting software and data. The paper concludes with a brief discussion of the complexities of requiring reproducibility in terms of cost versus benefit, and a desiderata with our observations and guidelines for improving reproducibility. This has implications not only in reproducing the work of others from published papers, but reproducing work from one’s own laboratory

Mesenchymal Stem Cells Modified with Heme Oxygenase-1 Have Enhanced Paracrine Function and Attenuate Lipopolysaccharide-Induced Inflammatory and Oxidative Damage in Pulmonary Microvascular Endothelial Cells

Background/Aims: Bone marrow-derived mesenchymal stem cell (BM-MSC) transplantation has therapeutic effects on endothelial damage during acute lung injury (ALI). Heme oxygenase-1 (HO-1) can restore homeostasis and implement cytoprotective defense functions in many pathologic states. Therefore, we explored whether transduction of HO-1 into BM-MSCs (MSCs-HO-1) would have an increased beneficial effect on lipopolysaccharide (LPS)-induced inflammatory and oxidative damage in human pulmonary microvascular endothelial cells (PVECs). Methods: MSCs were isolated from rat bone marrow and transfected with the HO-1 gene by a lentivirus vector. The phenotype and multilineage differentiation of MSCs were assessed. MSCs or MSCs-HO-1 were co-cultured with PVECs using a transwell system, and LPS was added to induce PVEC injury. The production of reactive oxygen species (ROS), and the activities of lipid peroxide (LPO), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in PVECs were determined by flow cytometry and colorimetric assays, respectively. The levels of human PVEC-derived tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 in the supernatants of the co-culture system, and the activity of nuclear transcription factor-κB and NF-E2-related factor 2 (Nrf2) in PVECs were examined by enzyme-linked immunosorbent assay (ELISA). The mRNA expression of TNF-α, IL-1β and IL-6 in PVECs was detected by quantitative real-time polymerase chain reaction (qRT-PCR), HO-1 expression and enzymatic activity in PVECs and the influence of zinc protoporphyrin (ZnPP) or HO-1 small interfering RNA on the above inflammatory and oxidative stress markers were evaluated. In addition, the expression of rat MSC-derived hepatocyte growth factor (HGF) and IL-10 was determined by ELISA and qRT-PCR. Results: MSCs showed no significant changes in phenotype or multilineage differentiation after transduction. LPS strongly increased the production of inflammatory and oxidative stress indicators, as well as decreased the levels of antioxidant components and the activity of Nrf2 in PVECs. MSC co-cultivation ameliorated these detrimental effects in PVECs and MSCs-HO-1 further improved the damage to PVECs induced by LPS when compared with MSCs alone. The beneficial effects of MSCs-HO-1 were dependent on HO-1 overexpression and may be attributed to the enhanced paracrine production of HGF and IL-10. Conclusion: MSCs-HO-1 have an enhanced ability to improve LPS-induced inflammatory and oxidative damage in PVECs, and the mechanism may be partially associated with the enhanced paracrine function of the stem cells. These data encourage further testing of the beneficial effects of MSCs-HO-1 in ALI animal models

PV grid-connected information interaction methods based on public information modeling

The grid integration of large-scale photovoltaic and other distributed energy sources is an effective solution for addressing power supply shortages and environmental pollution. However, the widespread adoption of photovoltaics and grid integration presents various technological and management challenges. To fulfill the demands of grid management and ensure safe operations, the exchange of information between different terminals is continuously escalating. Use of diverse communication standards creates the problem of “information islands” among terminals. Hence, a standardized information model is crucial for describing the photovoltaic grid integration business and enhancing the efficiency of related software platform research and development. This study extends the IEC 61970/61968 standards and presents a common information model for the integration of photovoltaic systems into the grid. Initially, the operational procedures for integrating photovoltaic systems into the grid are analyzed, and UML modeling tools are employed for business modeling purposes. Subsequently, leveraging the outcomes of the business modeling and the content of the IEC 61970/61968 standards, the development of the common information model is executed. Lastly, causal analysis is conducted along with the modeling of communication standard extensions specifically targeted for the integration of photovoltaic systems into the grid, culminating in the finalization of the construction of the common information model for photovoltaic grid connection