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For achieving the carbon peaking and carbon neutrality goals, the renewable energy and the battery energy storage will be developed more rapidly. The participation of the solar-wind-battery renewable energy system (SWBS) in black-start can improve the resilience of the power grid. Aiming at the balance between the capacity demand of SWBS participating in black-start and the benefit of SWBS, this paper proposes a positive-sum game-based SWBS capacity configuration planning method. First, a levelized cost of energy- (LCOE-) based full life cycle index is presented and constructs an economic benefit model of SWBS considering the participation of wind and solar power plants in carbon trading. Second, a black-start capacity demand model is constructed considering the continuous power demand on the auxiliary devices of the operated thermal power generator. Taking the economic benefit of SWBS and the black-start capacity requirement into account, this paper establishes a positive-sum game-based SWBS capacity optimal configuration model, in which maximizing the economic benefits of SWBS as an objective. Third, the simulation analysis is carried out by using a real power system, and results verify that the proposed method can achieve the optimal balance between the feasibility of black-start and the economic benefit of the SWBS. [ABSTRACT FROM AUTHOR]

Time-of-use (TOU) is an effective price-based demand response strategy. A reasonable design of TOU strategy can effectively reduce the peak-valley difference, and then produce a lot of benefits (such as delaying power grid investment, reducing interruption cost, and improving reliability). However, changing peak-valley period has a great influence on the peak-valley difference and power supply reliability of power system. Therefore, this paper aims to investigate the optimal modification of peak-valley period considering reliability loss under multiple TOU schemes. Firstly, this paper presents a clustering model and algorithm of optimal load curve based on a minimum error iteration method. Secondly, an optimal modification of peak-valley period based on a dynamic load point method is proposed, and the traditional peak-valley difference is replaced by the global peak-valley difference to calculate the objective function. Thirdly, this paper establishes a load–reliability relation fitting model based on the back propagation neural network. Finally, the effectiveness and correctness of the proposed method are investigated by the Roy Billinton test system and reliability test system. [ABSTRACT FROM AUTHOR]

• This paper proposes a reliability evaluation method considering the static frequency regulation for overcoming the shortcoming of the traditional reliability method. • This paper presents a failure restoration mode integrated into the reliability evaluation through designing system load curtailment, frequency restoration, and load restoration. • This paper establishes a series reliability calculating models which depend on the different failure restoration conditions. The adequacy of power system can be elevated with the increasing grid-connected capacity of wind farm, and meanwhile, the power system reliability is also affected by the intermittent power fluctuation of wind farm. However, the traditional reliability evaluation technique cannot take the power fluctuation into account. Therefore, for considering the positive and negative influence of wind energy on the power system reliability, this paper proposes a reliability evaluation technique through considering static frequency regulation and failure restoration process. A failure restoration strategy which can be integrated into the reliability evaluation model is presented through designing system load curtailment, system frequency restoration, and system load restoration strategies. A series reliability calculating models which depended on the different failure restoration conditions are established. Case studies for different systems are investigated, and the results verify that the proposed method can consider both aspects of the positive and negative influence of wind farm on the power system reliability. [ABSTRACT FROM AUTHOR]

Time of use pricing strategy can not only reduce the load fluctuation but also improve the power system reliability. Generally, before carrying out a time of use pricing optimization, it needs to perform a period partition optimization for dividing peak‐valley periods. In existing researches, however, the period partition optimization and the time of use pricing optimization are implemented independently. Although the output of period partition optimization is used as the input of time of use pricing optimization, the bidirectional feedback effect between period partition optimization and time of use pricing optimization is not considered, which will lead to the existing time of use pricing optimization may not be the globally optimal solution. Therefore, this paper investigates a new optimization method for time of use pricing optimization with the consideration of bidirectional feedback effect, establishes a comprehensive customer satisfaction degree model considering the customer load proportion coefficient, and defines an elastic cofactor to describe the electricity price response difference of multiple types of customers. The Roy Billinton test system is used to verify the correctness and effectiveness of the proposed method in this paper. [ABSTRACT FROM AUTHOR]

Natural gas, as a clean fossil energy, has been widely used in power generation system by converting chemical energy into electrical energy through gas turbines. However, the natural gas pipeline network system (NGPNS) is comprised of many equipments, and the failure of any equipment will probably cause the outage of gas turbines. Therefore, this study proposes an analytical method which can incorporate the uncertainty of NGPNS into the reliability assessment of integrated energy system. Firstly, on the basis of an analytical technique, NGPNS's operating states and the corresponding state probabilities are simulated. Secondly, a state transferring and equivalence technique is proposed for transferring the unreliability of NGPNS to the involved outage of gas turbines. Thirdly, an equivalent reliability model of gas turbine is established for taking into account the uncertainty of NGPNS. Finally, the NGPNS is connected to the Roy Billinton Test System through the coupling of gas turbines between electrical and gas networks. The results of case studies verify the correctness and effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Highlights • An optimization model for dividing on-peak, mid-peak and off-peak periods is established. • A demand management scheme with the participation of ESS is investigated. • A PSVF factor is proposed for describing the degree of participation of ESS. • A hybrid sampling method which can describe ESS's sequential process is presented. • Several indices for describing the influence of demand management scheme are defined. Abstract The energy storage system as a demand management resource can be incorporated into a power system for economizing the cost and improving the reliability. Therefore, this paper investigates the participation of energy storage system in demand management and its application to the reliability evaluation. Firstly, an optimal period partitioning model is proposed for dividing load series into the on-peak period, the mid-peak period, and the off-peak period, and a PSO based optimization algorithm is explored to optimize the unconstrained period partitioning problem which is transformed from the constrained optimization problem. Secondly, a demand management model with the participation of energy storage system is developed, and a peak shaving and valley filling factor is presented for describing the degree of demand management in this paper. Thirdly, a pseudo-analytical sampling method is presented for evaluating the reliability of the power system in the presence of energy storage system as a demand management resource, and some indices which can be used to describe the influence of demand management are defined. Finally, the Roy Billinton Test System and the Reliability Test System are conducted for verifying the correctness and validity of the proposed method. [ABSTRACT FROM AUTHOR]

• A method of period partitioning based on the silhouette coefficient is proposed. • A TOU price optimization model considering benefits and reliability is established. • A multi-objective simulated annealing particle swarm optimization algorithm is developed. • A bi-level TOU price optimization model for high reliability demand system is presented. The reliability of power system will vary with different demand response strategies, and it is significant to make a decision on demand response for satisfying differential reliability demand of power system. First, a peak-valley period partition model with an objective of maximizing silhouette coefficient was established based on the fuzzy clustering and step-wise iteration technology. Second, this paper proposed a multi-objective time of use electricity price optimization model considering the interests of both supply and demand sides, as well as reliability demand, and a multi-objective simulated annealing particle swarm optimization algorithm was developed to obtain solution. Third, the Pareto front curve of the dual-objective function was fitted by using a third-order Hermite interpolation algorithm, and the time of use prices corresponding to the reliability demand was obtained by using the back propagation neural network algorithm. Finally, the proposed model and algorithm were verified by the RBTS system, and the results indicate good rationality and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

This paper proposes an analytical method that incorporates the time of use (TOU) strategy into the reliability evaluation of power system. The TOU electricity price strategy enables the savings of electricity cost, but its impact on power system reliability has not been thoroughly studied. The proposed method constructs a peak-flat-valley period partition model and develops an equal step length iteration algorithm to obtain the optimal period partition. A price-based demand response is modeled to calculate the hourly load using an apportionment method. Using the particle swarm optimization algorithm, a TOU-based optimization model with a penalty is constructed to find the optimal electricity price. Then, an analytical “electricity price–reliability” model is developed to evaluate the reliability of the power system considering TOU. The effectiveness of the proposed method is investigated through the case study on the Roy Billinton test system and reliability test system. [ABSTRACT FROM AUTHOR]

Modelling wind profile is crucial to the adequacy assessment of wind-integrated generation system. This paper characterizes the wind profile as a wind vector that consists of wind speed and direction. A wind vector simulation model is proposed to produce long-term wind vector samples, whilst maintain the probability distribution of actual wind vector as well as its gusty characteristics. Such model is incorporated into sequential simulation process of wind-integrated generation system, while the wake effect is considered with Jensen model. Then, adequacy assessment procedure considering wake effect is developed. Collected wind vector data from four distinctive sites in North Dakota in US are used to verify the proposed model. The wind-integrated IEEE Reliability Test System (IEEE-RTS) is used to demonstrate the application of the proposed model and the procedure to adequacy assessment. The impacts of wake effect, peak load, and wind turbine type on system adequacy are investigated in detail. [ABSTRACT FROM AUTHOR]

Energy production of a wind farm is greatly affected by the wake-effect. In wind farm planning, it is essential to optimize the layout of wind turbine generators (WTGs) to alleviate the impact of wake-effect. This paper presents a new wind farm layout optimization model with an objective function to maximizing equivalent power of the wind farm. The proposed model incorporates the discrete joint probability distribution and characteristics of the wind, wind energy model, and the wake-effect. A particle swarm optimization algorithm is used to solve the optimization problem. In the optimization process, geometric analysis is conducted to determine the upstream WTGs and to calculate the horizontal and deviating distances among WTGs along the wind direction. An effective look-up table is constructed to directly determine the upstream/downstream WTGs. Then the optimal layout of a wind farm can be obtained. The proposed technique is applied to the wind farm layout optimization and the modified Roy Billinton Test System and IEEE Reliability Test System for reliability analysis of a generating system containing a wind farm. Simulation results demonstrate the validity and flexibility of the proposed technique in the layout optimization of WTGs in a wind farm. [ABSTRACT FROM AUTHOR]

Topology has a significant effect on the reliability performance of an electrical collector system (ECS) of wind farms. Novel indices for the reliability of wind farm ECS are presented based on topological features of wind farm ECS in this paper. The concept of the section for a wind farm ECS is defined. The probability table of multistate capacity (PTMC) for a wind turbine generator (WTG) and the Probability Table of the Number of WTG in Up-state (PTNU) for a section can be created. Based on the PTMC and PTNU, PTMC of a wind farm can be established using the state enumeration algorithm and the matrix operations. Therefore, the reliability evaluation model considering effects of wind speed and component failures can be built. The proposed model not only considers the multi-failures of ECS components including failures of cable feeder, WTG, and wind turbine transformer (WTT) but also states of switching devices in failure, disconnection, and switching processes. Four wind farm ECS topologies, i.e., radial topology, single-sided ring topology, double-sided ring topology, and star topology, are implemented. Case studies on the reliability evaluation of wind farm ECS are used to verify the feasibility and validity of the proposed technique. [ABSTRACT FROM AUTHOR]

• An optimal two-stage dispatch method for household PV-BESS system under TOU price. • A dynamic adjust strategy in the actual operation, with the subsequent plan update. • An energy storage strategy with the consideration of the sunrise time impact. The Photovoltaic (PV) and Battery Energy Storage Systems (BESS) integrated generation system is favored by users, because of the policy support of PV power generation and improvement of the grid-connected electricity price mechanism. And the operating efficiency and economy of the PV-BESS integrated generation system are closely related to the day-ahead dispatch strategy. Therefore, to improve the operating efficiency of the system and user benefit, this paper proposes an optimal two-stage dispatch strategy of household PV-BESS integrated generation system under the market environment of time-of-use (TOU) price strategy and a dynamic adjust strategy to cope with the forecast error. The first stage is the battery charging stage in the TOU price valley time, and the second stage is the PV output power dispatching and battery charge–discharge power scheduling stage in the non-valley time. The strategy combines energy storage strategy with a PV optimal dispatching strategy, to make full use of the double-sided characteristics of power source and load of the battery, thus achieving peak shaving and valley filling and reducing the load difference between peak and valley of the grid. The impact of sunrise time on energy storage strategy is also considered in this study. Then, the models of the two-stage dispatch strategy and the household PV-BESS integrated generation system are established under TOU price. When the PV output power is greater than the load demand, part of the surplus power will be sold to the grid and the other part will be stored in the battery. The ratio of the selling part is defined as the grid-connected ratio, and it is taken as the decision variable, and some factors are taken as the constraint condition, such as battery charge–discharge power, power balance, etc. The objective function is the optimal user benefit, and it is solved by the particle swarm optimization (PSO). When the forecast error happens, the power exchange of battery and the electricity sent to the grid will be adjusted, and the subsequent planning needs to be re-optimized to maintain the optimal dispatch result. Finally, the rationality and effectiveness of the models and strategies are verified by taking the dispatch of the household PV-BESS integrated generation system during a dispatch day under three typical scenarios as an example, and a sensitivity analysis is carried out. [ABSTRACT FROM AUTHOR]

The electrical system of a wind farm has a significant influence on the wind farm reliability and electrical energy yield. The disconnect switch installed in an electrical system cannot only improve the operating flexibility, but also enhance the reliability for a wind farm. Therefore, this paper develops a probabilistic transfer technique for integrating the electrical topology structure, the isolation operation of disconnect switch, and stochastic failure of electrical equipment into the reliability assessment of wind farm electrical system. Firstly, as the traditional two-state reliability model of electrical equipment cannot consider the isolation operation, so the paper develops a three-state reliability model to replace the two-state model for incorporating the isolation operation. In addition, a proportion apportion technique is presented to evaluate the state probability. Secondly, this paper develops a probabilistic transfer technique based on the thoughts that through transfer the unreliability of electrical system to the energy transmission interruption of wind turbine generators (WTGs). Finally, some novel indices for describing the reliability of wind farm electrical system are designed, and the variance coefficient of the designed indices is used as a convergence criterion to determine the termination of the assessment process. The proposed technique is applied to the reliability assessment of a wind farm with the different topologies. The simulation results show that the proposed techniques are effective in practical applications. [ABSTRACT FROM AUTHOR]

• The composite flexibility constraints are established to ensure the adequacy and availability of node flexible resources. • A two-stage robust optimization method of unit commitment with wind power generation considering composite flexibility is proposed. • The network flexibility balance degree (NFBD)& key lines constraint is developed to guarantee the system network balance level and network flexibility of key lines. The availability of power system flexible resources depends on the network flexibility, which plays a vital role in operation security of power systems with large-scale renewable energy. In this paper, a robust optimization method of unit commitment with wind power considering the composite flexibility constraints is proposed, which can ensure the availability of node flexible resources and then improve composite flexibility of power system. Firstly, the composite flexibility constraints of unit commitment problem are established. The composite flexibility reflects the mechanism of the interaction between node flexibility and network flexibility, which can consider the availability of node flexible resources and enable more accurately assessment of the system operation flexibility. Secondly, the concept of network flexibility balance degree is proposed to guarantee the overall network flexibility balance, and the network flexibility balance degree and key line constraints are developed to guarantee the system network balance level and the network flexibility of key lines, while improving the convergence speed of solving algorithm. Finally, the effectiveness of the proposed method is investigated through the case study on modified IEEE 24-bus system. [ABSTRACT FROM AUTHOR]

• A decentralized and coordinated scheduling method of interconnected multi-microgrid is proposed. • The virtual energy storage model for microgrid is established to express the potential flexibility. • The analytical target cascading is used to decouple the two-level optimization model. • The available flexible resource capacity of microgrid to the others are quantitatively analyzed. The joint coordinated optimization scheduling of multi-microgrid can reduce the risk of accommodation of renewable energy and the operation costs. In this paper, a decentralized and coordinated scheduling method of interconnected multi-microgrid based on virtual energy storage is proposed. Firstly, the microgrid is modelled as a virtual energy storage model, and the demand and supply are packaged into the charge and discharge states of the virtual energy storage model for information privacy of microgrid. Secondly, the probability characteristics of renewable energy prediction error and system flexible resource are used to quantify the operation risk of microgrid and the available charge and discharge power. The decentralized and coordinated scheduling method contains two-levels optimization model to optimize the power of tie-line and virtual energy storage. The upper is the central coordinate controller scheduling model, and the lower is the optimization scheduling model of sub-microgrid. The analytical target cascading is used to decouple the established upper and lower level models for independent optimization and solution. The proposed scheduling model ensures independent operation of each microgrid, and realizes decentralized autonomy and centralized coordinated management of multi-microgrid. Case studies demonstrate the correctness and a well economy of the proposed scheduling method. [ABSTRACT FROM AUTHOR]

Equipment maintenance decision is a very critical technology in power grid asset management. The traditional maintenance decision focuses on the analysis of the operation performance of the equipment itself, but lacks the analysis and description of the fuzziness of power equipment outage parameters. Therefore, this paper establishes the reliability assessment model based on equipment health condition monitoring, which makes the maintenance decision transition from equipment level to system level, and the fuzzy mathematics theory is introduced to establish a model describing the fuzziness of equipment failure rate parameter to make system reliability assessment and equipment maintenance decision scheme. Firstly, this paper proposes a fuzzy failure rate model of power transformer based on condition monitoring. Then the fuzzy parameters are combined with the conventional probabilistic reliability assessment method to establish the fuzzy probability hybrid reliability assessment model of the transmission system, and the fuzzy maintenance reliability benefit index is defined and deduced. Finally, a maintenance strategy of transformer based on fuzzy probability hybrid reliability assessment and fuzzy set theory is proposed, and the case study is carried out on a regional power grid in East China. The results show that the proposed model provides an improved maintenance strategy of power equipment. [ABSTRACT FROM AUTHOR]

Wind speed probability distributions estimated at relevant wind installation sites are widely used in electric power systems to evaluate appropriate wind energy indices in system performance and cost evaluation. An accurate estimation of wind speed probability distribution is essential to the increase of computational accuracy of these indices. To achieve this goal, a new analytical approach designated as the mixture kernel density model is developed. This model can produce highly accurate estimation of wind speed probability distributions. The mixture kernel density function consists of a selected number of kernel densities with weight coefficients. An analytic relation between the weight coefficients and the asymptotic integrated mean squared error is derived and used in the Lagrangian multiplier method to obtain the optimal weight coefficients that minimize the asymptotic integrated mean squared error. As a result, the requirement of choosing an optimal bandwidth in the conventional kernel density models is eliminated. The goodness-of-fit of the proposed mixture kernel density model and six conventional models is assessed on collected wind speed samples using the Chi-square and the Kolmogorov–Smirnov tests. Applicability of the proposed model is demonstrated using six types of wind turbine generators and three major wind energy assessment indices on eight actual wind sites. The results show that the mixture kernel density model is more accurate than other models for wind speed probability distribution estimation. Moreover, the most preferable wind turbine generator and the wind site containing the richest wind resources can be identified using the proposed model. [ABSTRACT FROM AUTHOR]

• An air conditioning load model suitable for the solution of the microgrid dispatching model is established. • A two-stage stochastic robust optimization model of microgrid with controllable air conditioning load is established. • The equivalent capacity of ESS of controllable air conditioning load under different dispatching temperatures is quantitatively analyzed. The wide application of wind power generation and photovoltaic (PV) power generation has greatly increased the uncertainty of power grid. Under the background of smart grid, peak shaving can be carried out with the help of users' equipment. This paper studies the cooling efficiency of air conditioning from the heat transfer process between room and outdoor, and establishes the air conditioning load control model. Based on this, a stochastic robust day-ahead dispatching model for microgrid is proposed, taking cost minimization as objective function. The day-ahead dispatching is considered as the first stage which considering the arrangement of electricity purchasing and generating of thermal power units. The real-time dispatching is regarded as the second stage. Based on the results of the first stage, real-time dispatching of the various situations of the renewable energy output can be carried out. The decision variables are air conditioning control and ESS charge and discharge arrangement. Then the results are fed back to the first stage, and the cost is minimized by iteration. In this paper, the double-layer problem in the second stage is transformed into a single-layer problem by mathematical method, and the Column-and-Constraint Generation (CCG) algorithm is used to solve the two-stage stochastic robust optimization model. Finally, based on the data of a microgrid in a central city, the effectiveness of the method is verified, and the economic superiority of the day-ahead dispatching model at stochastic and robust level is discussed. [ABSTRACT FROM AUTHOR]

• A flexibility enhancement pre-selection strategy based on network flexibility balance degree and line outage distribution factor is proposed. • The available flexibility index (AFI) is proposed to quantify the supply of system flexibility. • An optimization model of power system flexibility enhancement method based on pre-selection of structure adjustment strategy is proposed. The flexibility enhancement method of power system usually focuses on node flexible resource, without considering the transmission process. It may result in some flexible resources not being transferred, thus affecting the accuracy and effectiveness of the flexibility enhancement. In this paper, a flexibility enhancement optimization model based on pre-selection method of structure adjustment strategy is proposed, which can improve system flexibility with guaranteed availability of flexible resources. Firstly, the flexibility enhancement pre-selection method based on power system topology adjustment mathematical formulation is proposed to select the lines suitable for topology adjustment. Secondly, a flexibility enhancement optimization model considering economy and available flexibility is developed, which takes the maximum available flexibility index as the objective function and ensures the system flexible and economical by cost-floating constraint. The available flexibility deviation constraint corrects the system flexibility supply to guarantee the accuracy of available flexibility. Finally, the effectiveness of the proposed method is investigated through the case study on modified IEEE 24-bus and IEEE 118-bus system. [ABSTRACT FROM AUTHOR]

Purpose: To compare the clinical efficacy of mini-open (air/water medium) endoscopy-assisted anterior cervical discectomy and fusion (MOEA-ACDF) and anterior cervical decompression and fusion (ACDF) for cervical spondylotic myelopathy (CSM).This study retrospectively analysed the clinical data of CSM patients who received surgical treatment from January 1, 2020, to December 31, 2022. Patients were divided into two groups according to the surgical method: the MOEA-ACDF group and the ACDF group. The preoperative and postoperative imaging results at one week and the last follow-up examination were compared between the two groups. The Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score and neck disability index (NDI) score were used to evaluate the clinical outcomes preoperatively, one week postoperatively and at the last follow-up examination. The minimum follow-up duration was 12 months.A total of 131 CSM patients who underwent surgery at our institution were included, including 61 patients in the MOEA-ACDF group and 70 patients in the ACDF group. In the MOEA-ACDF group, the postoperative C2-C7 Cobb angle and HAVB were significantly greater than the preoperative values (P < 0.05). In the ACDF group, the postoperative C2-C7 Cobb angle was also significantly greater than the preoperative value, and the C2-C7 ROM and HAVB significantly decreased (P < 0.05). The postoperative neurological function of the patients in both groups improved, and the postoperative VAS score and NDI score significantly decreased. Compared with ACDF, MOEA-ACDF is associated with a significantly larger postoperative C2-C7 Cobb angle and significantly better C2-C7 ROM and HAVB, as well as better clinical efficacy (P < 0.05).MOEA-ACDF combines endoscopic systems with ACDF technology to treat CSM, but its clinical efficacy is not inferior to that of ACDF in the short- to intermediate-term. It can effectively and safely restore the cervical intervertebral height, physiological curvature, and range of motion.Methods: To compare the clinical efficacy of mini-open (air/water medium) endoscopy-assisted anterior cervical discectomy and fusion (MOEA-ACDF) and anterior cervical decompression and fusion (ACDF) for cervical spondylotic myelopathy (CSM).This study retrospectively analysed the clinical data of CSM patients who received surgical treatment from January 1, 2020, to December 31, 2022. Patients were divided into two groups according to the surgical method: the MOEA-ACDF group and the ACDF group. The preoperative and postoperative imaging results at one week and the last follow-up examination were compared between the two groups. The Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score and neck disability index (NDI) score were used to evaluate the clinical outcomes preoperatively, one week postoperatively and at the last follow-up examination. The minimum follow-up duration was 12 months.A total of 131 CSM patients who underwent surgery at our institution were included, including 61 patients in the MOEA-ACDF group and 70 patients in the ACDF group. In the MOEA-ACDF group, the postoperative C2-C7 Cobb angle and HAVB were significantly greater than the preoperative values (P < 0.05). In the ACDF group, the postoperative C2-C7 Cobb angle was also significantly greater than the preoperative value, and the C2-C7 ROM and HAVB significantly decreased (P < 0.05). The postoperative neurological function of the patients in both groups improved, and the postoperative VAS score and NDI score significantly decreased. Compared with ACDF, MOEA-ACDF is associated with a significantly larger postoperative C2-C7 Cobb angle and significantly better C2-C7 ROM and HAVB, as well as better clinical efficacy (P < 0.05).MOEA-ACDF combines endoscopic systems with ACDF technology to treat CSM, but its clinical efficacy is not inferior to that of ACDF in the short- to intermediate-term. It can effectively and safely restore the cervical intervertebral height, physiological curvature, and range of motion.Results: To compare the clinical efficacy of mini-open (air/water medium) endoscopy-assisted anterior cervical discectomy and fusion (MOEA-ACDF) and anterior cervical decompression and fusion (ACDF) for cervical spondylotic myelopathy (CSM).This study retrospectively analysed the clinical data of CSM patients who received surgical treatment from January 1, 2020, to December 31, 2022. Patients were divided into two groups according to the surgical method: the MOEA-ACDF group and the ACDF group. The preoperative and postoperative imaging results at one week and the last follow-up examination were compared between the two groups. The Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score and neck disability index (NDI) score were used to evaluate the clinical outcomes preoperatively, one week postoperatively and at the last follow-up examination. The minimum follow-up duration was 12 months.A total of 131 CSM patients who underwent surgery at our institution were included, including 61 patients in the MOEA-ACDF group and 70 patients in the ACDF group. In the MOEA-ACDF group, the postoperative C2-C7 Cobb angle and HAVB were significantly greater than the preoperative values (P < 0.05). In the ACDF group, the postoperative C2-C7 Cobb angle was also significantly greater than the preoperative value, and the C2-C7 ROM and HAVB significantly decreased (P < 0.05). The postoperative neurological function of the patients in both groups improved, and the postoperative VAS score and NDI score significantly decreased. Compared with ACDF, MOEA-ACDF is associated with a significantly larger postoperative C2-C7 Cobb angle and significantly better C2-C7 ROM and HAVB, as well as better clinical efficacy (P < 0.05).MOEA-ACDF combines endoscopic systems with ACDF technology to treat CSM, but its clinical efficacy is not inferior to that of ACDF in the short- to intermediate-term. It can effectively and safely restore the cervical intervertebral height, physiological curvature, and range of motion.Conclusions: To compare the clinical efficacy of mini-open (air/water medium) endoscopy-assisted anterior cervical discectomy and fusion (MOEA-ACDF) and anterior cervical decompression and fusion (ACDF) for cervical spondylotic myelopathy (CSM).This study retrospectively analysed the clinical data of CSM patients who received surgical treatment from January 1, 2020, to December 31, 2022. Patients were divided into two groups according to the surgical method: the MOEA-ACDF group and the ACDF group. The preoperative and postoperative imaging results at one week and the last follow-up examination were compared between the two groups. The Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score and neck disability index (NDI) score were used to evaluate the clinical outcomes preoperatively, one week postoperatively and at the last follow-up examination. The minimum follow-up duration was 12 months.A total of 131 CSM patients who underwent surgery at our institution were included, including 61 patients in the MOEA-ACDF group and 70 patients in the ACDF group. In the MOEA-ACDF group, the postoperative C2-C7 Cobb angle and HAVB were significantly greater than the preoperative values (P < 0.05). In the ACDF group, the postoperative C2-C7 Cobb angle was also significantly greater than the preoperative value, and the C2-C7 ROM and HAVB significantly decreased (P < 0.05). The postoperative neurological function of the patients in both groups improved, and the postoperative VAS score and NDI score significantly decreased. Compared with ACDF, MOEA-ACDF is associated with a significantly larger postoperative C2-C7 Cobb angle and significantly better C2-C7 ROM and HAVB, as well as better clinical efficacy (P < 0.05).MOEA-ACDF combines endoscopic systems with ACDF technology to treat CSM, but its clinical efficacy is not inferior to that of ACDF in the short- to intermediate-term. It can effectively and safely restore the cervical intervertebral height, physiological curvature, and range of motion. [ABSTRACT FROM AUTHOR]

Wind profile, wake effect, and wind turbine outage create considerable impact on the energy production of a wind farm. This paper proposes a Markovian wind farm generation model that incorporates these factors. This model considers the wind farm as a generating unit with multiple generation states. The probability, frequency of occurrence, and transition rate of each state can be obtained using the collected wind profile data and wind turbine reliability parameters. The power output of each state is calculated using Jensen wake model and enumerated wind farm layouts. The proposed model is verified by a sequential Monte Carlo simulation approach using a test wind farm and recorded wind profile data from four different sites in North Dakota, USA. A state merging technique is developed to enable the application of the proposed model to adequacy assessment. The Roy Billiton Test System with a test wind farm is used to demonstrate the application of the proposed model and the procedure to adequacy assessment. Moreover, this paper investigates the influence of wake effect, peak load, seasonal wind pattern, wind turbine reliability parameters, and wind turbine type on system adequacy. [ABSTRACT FROM AUTHOR]

The paper presents theoretical results on the global asymptotic stability and synchronization of a class of fractional-order memristor-based neural networks (FMNN) with multiple delays. First, the asymptotic stability of fractional-order (FO) linear systems with single or multiple delays is discussed. Delay-independent stability criteria for the two types of systems are established by using the maximum modulus principle and the spectral radii of matrices. Second, new testable algebraic criteria for ensuring the existence and global asymptotic stability of the system equilibrium point are obtained by employing the Kakutani’s fixed point theorem of set-valued maps, the comparison theorem, and the stability criterion for FO linear systems with multiple delays. Third, the synchronization criterion for FMNN is presented based on the linear error feedback control. Finally, numerical examples are given demonstrating the effectiveness of the proposed results. [ABSTRACT FROM AUTHOR]

Mitochondrial impairment is hypothesized to contribute to the pathogenesis of chronic cholestatic liver diseases. Mitofusin 2 (Mfn2) regulates mitochondrial morphology and signaling and is involved in the development of numerous mitochondrial-related diseases; however, a functional role for Mfn2 in chronic liver cholestasis which is characterized by increased levels of toxic bile acids remain unknown. Therefore, the aims of this study were to evaluate the expression levels of Mfn2 in liver samples from patients with extrahepatic cholestasis and to investigate the role Mfn2 during bile acid induced injury in vitro. Endogenous Mfn2 expression decreased in patients with extrahepatic cholestasis. Glycochenodeoxycholic acid (GCDCA) is the main toxic component of bile acid in patients with extrahepatic cholestasis. In human normal hepatocyte cells (L02), Mfn2 plays an important role in GCDCA-induced mitochondrial damage and changes in mitochondrial morphology. In line with the mitochondrial dysfunction, the expression of Mfn2 decreased significantly under GCDCA treatment conditions. Moreover, the overexpression of Mfn2 effectively attenuated mitochondrial fragmentation and reversed the mitochondrial damage observed in GCDCA-treated L02 cells. Notably, a truncated Mfn2 mutant that lacked the normal C-terminal domain lost the capacity to induce mitochondrial fusion. Increasing the expression of truncated Mfn2 also had a protective effect against the hepatotoxicity of GCDCA. Taken together, these findings indicate that the loss of Mfn2 may play a crucial role the pathogenesis of the liver damage that is observed in patients with extrahepatic cholestasis. The findings also indicate that Mfn2 may directly regulate mitochondrial metabolism independently of its primary fusion function. Therapeutic approaches that target Mfn2 may have protective effects against hepatotoxic of bile acids during cholestasis. [ABSTRACT FROM AUTHOR]