Efficient building energy management is essential for energy saving and green society. This paper investigates sustainable energy management for an energy building cluster with distributed ...transaction. The building cluster consists of several types of energy buildings, e.g., office, industrial, and commercial buildings. We first formulate utility functions for the buildings of consuming energy based on the characteristics of their controllable loads. Then a two-stage energy sharing strategy is presented. In the first stage, the total social energy cost is minimized through finding the optimal energy sharing profiles in a distributed way. In the second stage, the clearing for mutual energy sharing is modeled as a non-cooperative game, and the existence of the equilibrium of the game is illustrated and a relaxation-based algorithm is introduced to search for the equilibrium. Moreover, a real-time model for each building to overcome real-time uncertainties, such as renewable energy generation and base loads is provided. The simulation results show that the proposed energy sharing strategy is economically beneficial for the energy buildings, computationally efficient, and is promising to facilitate a sustainable regional building cluster.
With the rapid development of energy buildings, advanced energy management is urgently demanded for a green society. In this paper, focusing on the coordinated energy management for a building ...community, we present a new and fair peer-to-peer energy sharing framework to realize an economic and sustainable building community. Specifically, in the building-centric peer-to-peer mode, buildings directly share their energy supplies/demands and offer the related payments within the community under the constraints of community energy and payment balance. We propose a non-cooperative energy sharing game for the selfish buildings, and we further show that a generalized Nash equilibrium of the game is independent of the energy sharing payments. Consequently, we firstly derive the energy sharing profiles by seeking the equilibrium. Since the buildings' energy sharing payments are mutually coupled and influenced, we propose a cost reduction ratio distribution model to determine the payments to ensure the fairness in the sense that buildings can get as large cost reductions and similar cost reduction ratios as possible. Simulation results show that all buildings can reduce their energy costs and have smoother and smaller net demand profiles on the main grid, thus making the proposed schemes and algorithms promising in real applications.
The spot electricity market (SEM) faces the challenge of inefficiency problems from market power (MP) abuse. However, previous studies have not adequately addressed such issues as the feasibility of ...MP mitigation measurements and authenticity of MP detection indicators. In this study, mitigation methods are developed, and MP detection indicators are designed to detect and mitigate the exercise of MP in an SEM in which multiple generators compete unilaterally through a uniform marginal clearing price mechanism. First, the incentives and general rules for rational generators to exercise their MP are analysed, providing theoretical support for the developed approaches. Then, two mechanisms that can mitigate the exercise of MP are devised by limiting the bid increase rate and maximising the consumer surplus. Furthermore, a behavioural detection indicator is designed to measure the MP of an individual generator, while an overall indicator is defined to assess the MP of an entire market. Finally, a joint clearing model is established to help implement the mechanism while promoting a high proportion of renewable energy consumption in the SEM. Case studies demonstrate the effectiveness and feasibility of the proposed approaches.
•The necessary and sufficient conditions for electricity market bidding equilibria are given.•Two market power detection indicators for individuals and overall market are designed.•Two market power mitigation measures are proposed and their effectiveness is proved.•A joint clearing model is proposed for traditional and renewable energy generators.
Household photovoltaic (HPV) prosumers and the community photovoltaic (CPV) system have been growing rapidly with the development of the sustainable technology. The uncertainties of these distributed ...renewable energy resources bring a significant challenge to the design of power-market mechanism and the energy dispatch of the power system for promoting energy efficiency. It is essential to develop a novel efficient energy management strategy for addressing this challenge from the perspective of community prosumers. Accordingly, a risk aversion energy sharing model based on a devised local energy market is presented. A stochastic game is established to minimize prosumers' energy costs and the weighted conditional value-at-risk of energy sharing loss of uncertain CPV through optimal energy sharing profiles. The household loads and HPV outputs are considered as stochastic parameters in the game model. Moreover, a sample weighted average approximation (SWAA) method is proposed for a better estimation of the stochastic game while the SWAA equilibrium is obtained by a relaxation method-based algorithm with theoretical proof. In addition, the blockchain technology is introduced as a distributed and secure way to facilitate the energy sharing model. The case studies show the efficiency of the proposed energy sharing model and the algorithm.
Base station (BS) backup batteries (BSBBs), with their dispatchable capacity, are potential demand-side resources for future power systems. To enhance the power supply reliability and ...post-contingency frequency security of power systems, we propose a two-stage stochastic unit commitment (UC) model incorporating operational reserve and post-contingency frequency support provisions from massive BSBBs in cellular networks, in which the minimum backup energy demand is considered to ensure BS power supply reliability. The energy, operational reserve, and frequency support ancillary services are co-optimized to handle the power balance and post-contingency frequency security in both forecasted and stochastic variable renewable energy (VRE) scenarios. Furthermore, we propose a dedicated and scalable distributed optimization framework to enable autonomous optimizations for both dispatching center (DC) and BSBBs. The BS model parameters are stored and processed locally, while only the values of BS decision variables are required to upload to DC under the proposed distributed optimization framework, which safeguards BS privacy effectively. Case studies on a modified IEEE 14-bus system demonstrate the effectiveness of the proposed method in promoting VRE accommodation, ensuring post-contingency frequency security, enhancing operational economics, and fully utilizing BSBBs' energy and power capacity. Besides, the proposed distributed optimization framework has been validated to converge to a feasible solution with near-optimal performance within limited iterations. Additionally, numerical results on the Guangdong 500 kV provincial power system in China verify the scalability and practicality of the proposed distributed optimization framework.
The present study describes circular RNA (circRNA) profiles in three pairs of hepatocellular carcinoma (HCC) tissues and the corresponding adjacent non-tumorous tissues (NTs) by microarray. circRNA ...is a type of endogenous RNA that serve a crucial role in disease development and aberrantly express in a number of types of cancer. In the present study, 3 paired HCC tissues and paired adjacent NTs were collected from HCC surgical specimens from 3 hepatitis B virus-infected patients with HCC. With abundant and varied probes accounting for 5,396 circRNAs, a large number of circRNAs are able to be quantitatively determined. Based on the microarray data, 222,567,556 upregulated circRNAs and 125,439,219 downregulated circRNAs were identified respectively. Further analysis revealed 24 upregulated and 23 downregulated significantly circRNAs (fold-change ≥2; P≤0.05) in HCC tissues compared with NTs. By means of computer analysis and database inquiring, the microRNA (miRNA) response elements associated with the abnormally expressed circRNAs were annotated. The present study showed novel evidence determining genome-wide circRNA expression patterns in HCC using microarray analysis. The results demonstrated that clusters of circRNAs were aberrantly expressed in HCC compared with NTs. These circRNAs may be involved in the occurrence and development of HCC. Therefore, the results of the present study may provide a novel approach for improving the understanding of the molecular basis of HCC. Furthermore, the identified circRNAs may be potential biomarkers for the diagnosis of HCC.
Circular RNAs (circRNAs) play an important role in pathogenesis and development of hepatocellular carcinoma (HCC). However, circRNA expression profiles in hepatitis B Virus (HBV)-related HCC remain ...to be studied.
Total 13 HBV-related HCC patients were enrolled for study. Three HCC and 3 paired adjacent non-tumorous (NT) tissues from 3 patients were performed for microarray. Ten pairs of HCC tissues were used to verify the identified up-regulated and down-regulated circRNAs obtained from the microarray data by quantitative real-time reverse transcription PCR (qRT-PCR). Total RNA was isolated and treated with Rnase R to remove linear RNA, then hybridized to the array to screen for circRNAs. Bioinformatics analyses including clustering, differential expression, annotation of circRNA/microRNA (miRNA) interactions, Go analysis and KEGG pathway analysis, were performed.
Based on the microarray data, we found significantly up-regulation of 24 circRNAs and down-regulation of 23 circRNAs in the HCC samples compared to NT samples (fold change ⩾ 2.0 and P< 0.05). Of them, 6 candidate circRNAs (hsa_circRNA_102814, 100381, 103489, 101764, 100327, and 103361) were verified by qRT-PCR. Of them, hsa_circRNA 100381, 103489 up-regulation and 101764 down-regulation were found to be significantly different in the 10 validation HCC tissue. Clusters of circRNAs were aberrantly expressed in HCC compared with NT samples. CircRNA_101764 was the largest nodes in circRNA/microRNA co-expression network, especially co-expression with hsa-miR-181 family, which plays an important role in cell network. Annotation of circRNA/miRNA interactions indicated that the biological effects of circRNA may be achieved by binding of miRNAs. GO analysis revealed that numerous target genes were involved in the biological processes, cellular component and molecular function. There was nearly 30 target genes enrichment on KEGG pathways analysis, PI3K-Akt signaling pathway which the most number of genes involved.
In this study, we comprehensively explored the expression of differentially expressed circRNAs in HBV-related HCC, and our results indicate that circRNA_101764 may play an important role in the development of HCC.
Fossil fuel depletion and environmental pollution problems promote development of renewable energy (RE) globally. With increasing penetration of RE, operation security and economy of power systems ...(PS) are greatly impacted by fluctuation and intermittence of renewable power. In this paper, information gap decision theory (IGDT) is adapted to handle uncertainty of wind power generation. Based on conventional IGDT method, linear regulation strategy (LRS) and robust linear optimization (RLO) method are integrated to reformulate the model for rigorously considering security constraints. Then a robustness assessment method based on hybrid RLO-IGDT approach is proposed for analyzing robustness and economic performance of PS. Moreover, a risk-averse linearization method is adapted to convert the proposed assessment model into a mixed integer linear programming (MILP) problem for convenient optimization without robustness loss. Finally, results of case studies validate superiority of proposed method in guaranteeing operation security rigorously and effectiveness in assessment of RSR for PS without overestimation.
Purposes: This study aimed to investigate the efficacy of ultrasound (US)-, computed tomography (CT)-, and magnetic resonance imaging (MRI)-guided radiofrequency ablation (RFA) for the treatment of ...hepatocellular carcinoma (HCC).
Materials and Methods: This retrospective study included 141 patients with HCC who were treated with US-guided (n = 29), CT-guided (n = 50), or MRI-guided RFA (n = 62). The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival (OS), technique success (TS), and technique efficacy (TE). Cox model and logistic regression were used to determine the risk factors for tumor recurrence and TE.
Results: The US, CT, and MRI groups did not show a significant difference in terms of baseline variables. The three groups did not differ significantly in PFS rate (P = 0.072) and OS rate (P = 0.231). The PFS rates at 3 years for the US, CT, and MRI groups were 40.90%, not reached, and 14.80%, respectively. The OS rates at 3 years were 94.70%, 97.50%, and 85.50% for US, CT, and MRI groups, respectively. No significant differences were observed between the three groups in terms of TS rate (P = 0.113) and TE rate (P = 0.682). In multivariate analysis, liver cirrhosis (P = 0.001), level of alpha-fetoprotein (AFP, P = 0.004), and number of tumors (P = 0.012) were independent risk factors for PFS. For TE, the level of AFP (P = 0.018) was an independent factor.
Conclusion: US-, CT-, and MRI-guided RFA was effective for treating HCC patients. Liver cirrhosis, AFP level, and tumor number were associated with tumor recurrence, and the level of AFP was an independent risk factor affecting TE.
•A united energy management for a community of energy buildings is investigated.•A game-based peer-to-peer energy sharing management model is proposed.•An efficient distributed algorithm is proposed ...to seek the game equilibrium.•The efficiency of the proposed model is verified by several simulation cases.
Energy building techniques have gained significant attention for the potential to achieve local energy sustainability. Different from the research on individual energy management for zero energy buildings requiring sufficiently large renewable energy systems due to the mismatch of energy loads and generations, this paper investigates the coordinated energy management for a community of energy buildings with peer-to-peer energy sharing to promote community energy efficiency. Specifically, the energy buildings have controllable heating, ventilation and air conditioning (HVAC) units and renewable energy installations. In the coordinated energy management, in a peer-to-peer mode, the buildings determine their energy sharing profiles and related payments within the community while the sharing energy balance and payment balance are required to be satisfied. Since the buildings are self-interested, the problem with peer-to-peer energy sharing is modeled as a noncooperative game with global constraints. Then the existence of the game equilibrium is illustrated, and a distributed algorithm is proposed to seek the game equilibrium. A 6-building case and a 30-building case are carried out to verify the energy efficiency, economic benefits, and the scalability of the proposed peer-to-peer energy sharing management model.
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