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With the rapid development of e-commerce and the increasing popularity of smartphones, online shopping has become a trend of the times, and various online shopping platforms have emerged endlessly. As a new type of shopping platform, the micro store has gradually occupied a place in online shopping with its unique characteristics. In this context, the dissertation first introduces the management of micro-store operation models; then, it summarizes the causes of micro-store operation model risks into seven aspects.

Optimally operating an integrated electricity-gas system (IEGS) is significant for the energy sector. However, the IEGS operation model's nonconvexity makes it challenging to solve the optimal dispatch problem in the IEGS. This letter proposes a new Benders decomposition-based (IBD) algorithm catering to a commonly used steady-state dispatch model of the IEGS. This IBD algorithm leverages a refined decomposition structure where the subproblems are linear and ready to be solved in parallel. We analytically compare our IBD algorithm with an existing Benders decomposition algorithm and a typical piecewise linearization method. Case studies have substantiated the higher computational efficiency of our IBD algorithm.

As the mine backfill is recognized as one promising technique for the sustainable development, it is crucial to explore the backfill operation mechanism for the mining industry. At present, the self-management and outsourcing model are generally selected to apply in backfill operation and management worldwide. The advantages are insufficient from the strategic and sustainable perspective. Therefore, the study proposes joint venture alliance and concerns the superiority on mine backfill management. In order to evaluate the models, this study puts forward the integrated method which involves combination of SBSC and IFAHP. A strategic and hierarchical framework of SBSC on the basis of sustainability is formulated, which includes 6 perspectives and 16 secondary indexes. Simultaneously, the IFAHP approach is used for determination of the weights of indexes and calculation of the final score, which enables to assess mine backfill operation activity more objectively. The results show that the self-management model provides little advantages whereas the outsourcing model is the better operation mechanism. By contrast, joint venture alliance is rated as the optimal backfill operation model of the mining industry. The research findings of this study would help the mining industry to evaluate objectively and make an appropriate decision on the backfill operation model in the mining industry.

O cenário de avanço econômico de países emergentes e a descentralização da economia global, vivenciado nas últimas décadas, aumentou o uso do modal aquaviário, já que este é o tipo de transporte mais eficiente para grandes cargas a longas distâncias, como acontece nas exportações e importações. Entretanto, esse aumento da demanda tem evidenciado aos terminais portuários a necessidade de um gerenciamento logístico eficiente para evitar o acúmulo de filas e um longo tempo de espera nos processos de carga e descarga de navios. Nesse contexto, o objetivo deste trabalho é elaborar uma proposta de atendimento de clientes e movimentação de cargas que minimize o tempo de espera dos navios no Porto de Itajaí. A partir de uma entrevista semiestruturada e do acompanhamento das operações no porto, foi construído um modelo conceitual, e, posteriormente, traduzido em um modelo computacional, que foi validado em relação ao modelo real de funcionamento do terminal. Também foi feita uma análise dos processos e levantamento de oportunidades de melhoria para as operações, que permitiu a construção de três modelos alternativos de atendimento, que foram simulados no software ArenaÒ e os resultados foram comparados para identificar a melhor solução para a operação do Porto de Itajaí.

Regarding China’s traditional manufacturing industry there is a large gap compared with developed countries in terms of green manufacturing development. As environmental problems become more serious, resources and environmental constraints prevent its further development. China has now incorporated green manufacturing into an urgent future development strategy, and the green manufacturing system has been gradually integrated into its industrial development strategy. This paper analyses the gap between China’s traditional manufacturing and the rest of the world’s industry-leading level. It discusses the structure of China green manufacturing development and operation model in progress. It further expounds the complementarity between China and Germany in green manufacturing while emphasizing the Sino-German cooperation methods and approaches.

The application of power electronics can introduce flexibility into power systems, but it can also cause harmonic problems. As a typical application of power electronics, high-voltage direct current (HVDC) transmission exhibits very prominent harmonic problems. In recent years, many HVDC protection maloperation events caused by harmonic problems have occurred in the field. The phenomena of harmonic transfer and amplification in HVDC transmission have an undeniable impact on the overall operation of a power system. Previous studies of these phenomena have relied mainly on detailed electromagnetic transient simulations. However, these simulations normally suffer from a large computational burden and low efficiency due to the complexity of the models and the small simulation time steps used. Therefore, an efficient analysis model of harmonics for various HVDC operating modes is presented in this paper. This model is based on port theory; every part of the HVDC transmission system is represented by an equivalent two-port component to construct a unified equivalent circuit. The proposed model is simple to calculate, and only the connections of the two-port components need to be changed to model different operation modes. The proposed two-port model is applied for the harmonic analysis of an HVDC transmission system, and the validity and accuracy of the model are confirmed by detailed electromagnetic simulations. Moreover, the model can be easily applied to HVDC systems for harmonic transfer and amplification, and the effects of the HVDC transmission power and smoothing reactor on harmonic transfer and amplification are analyzed.

The risk of flood or waterlogging in irrigation districts has increased due to global climate change and intensive human activities. A Model of Optimal Operation of Drainage Works (MOODW) for flat irrigation district was established by incorporating the hydrological model of waterlogging process and waterlogging loss estimation, which was solved by an optimization method of genetic algorithm. The model of waterlogging process was built based on a modified Tank model and hydrodynamic model for the ditch-river system. The waterlogging loss is calculated under the condition of inconstant inundated depth by linear interpolation. The adaptive genetic algorithm with the global optimization function was selected to solve the model. With an extreme rainfall events in Gaoyou irrigation district as cases, results showed that operation time and numbers of pumps increased, thus, operating costs were 1.4 times higher than before, but the yield loss of rice decreased by 35.4% observably. Finally, the total waterlogging loss was reduced by 33.8% compared with the traditional operation of waterlogging work. The most significant improvement was found in units with high waterlogging vulnerability. The MOODW can provide the waterlogging information visually and assist the district manager in making a reasonable decision.

A method of decomposition of the electrical circuit is considered, which allows to obtain its systemic representation, which simplifies the identification of the principles and features of its functioning. On the example of an electrical circuit of a transistor radio receiver of direct amplification, the process of its structuring is shown according to the physical principle of action laid down in it, which allows its further decomposition. The method allows you to represent an electrical circuit in the form of a four-level model, which makes it possible to work with it for developers of different qualifications.

Knowing that the demand for advertising in a growing e-commerce market cannot be sufficiently addressed in a traditional advertising operation model, advertisers and e-commerce platforms apply arti...

The increasing complexity of power systems, particularly the high renewable energy penetration, raises the necessity of incorporating detailed power system operation models into long-term planning studies. The classic short-term operation model, i.e., network-constrained unit commitment (NCUC), involves many binary variables and introduces computational challenges when applied to long-term planning optimizations. A high-efficiency and simplified NCUC model is required to incorporate operational flexibility in power system planning studies. This paper proposes a linearized NCUC formulation that has a high calculation performance and minor approximation errors compared to the full NCUC model. The proposed model combines the dispatch-only (DO) operation model and clustered unit commitment (CUC) model by introducing linking constraints between them such that the overall model guarantees both the transmission security constraints that are formulated in the DO model and the start-up/shut-down constraints of generating units that are formulated in the CUC model. A case study of a modified IEEE RTS-79 system is provided to demonstrate the validation and efficiency of the proposed simplified NCUC model as well as its effectiveness for power system planning studies.

Optimization of the stock management process is associated with the search for a forecasting model, a method for generation of a forecasting time series, a model of logistic operation, determining a reasonable level of reserve stocks and establishing the optimization criterion. Successful solution to the optimization problem in general can be achieved only if the whole complex of local management problems is successfully solved. In this case, the method of generation of a cointegrated time series of demand forecasting is the central element of the technology of optimal stocks management. This relates to the fact that probabilistic nature of demand is the main factor reducing efficiency of management in systems of this class. It was shown that the proposed method for improving management efficiency can be used in any economic system due to the possibility of construction of a single logistic operation model. The proposed approach is based on formation of a time series specifically designed to solve the problem of forecasting the demand in stocks buffering systems. Such a series contains both information on sales volumes and data related to consumer demand. Since consumer activity is ahead of the process of physical consumption of products, it becomes possible to use anticipatory markers in forecasting problems. The study of operational processes using a verified indicator of efficiency has confirmed the hypothesis of presence of anticipatory markers within the framework of the formed forecast time series. It has been established that the maximum management efficiency can be achieved in the case of a lower construction accuracy of the forecast model. This is due to the fact that the logistic operation model takes into account the costs of movement of products and their valuation at the operation input and output.

Careful design of catalytic reactors can reduce both the cost and risk associated with new designs and can reduce ownership costs significantly through better performance during operation. Digital design techniques based on high-fidelity predictive models now afford a way of doing this rapidly and effectively. Such techniques make it possible to perform detailed design of multitubular reactors taking into account multiscale effects, from catalyst pore to industrial reactor, by combining high-fidelity models with model-targeted experimentation. Further benefits can be realized by implementation of the detailed model online for monitoring, forecasting, and optimization. This paper introduces the digital design approach for design, optimization, and online implementation of fixed-bed catalytic reactors, with examples taken from selected industrial cases.

Water supply for agricultural organizations in sufficient quantity and quality with minimum costs is the foundation of efficient production and raw materials for some industries, as well as the basis for water management.This article discusses the features and operation problems in water supply systems, surpluses on the balance of agricultural organizations. Science-based approaches to optimize the operation of water supply systems are presented in the article.For planning and control of exploitation of water supply systems in agricultural organizations it is recommended to group all repair and maintenance works into stages. These stages vary in purpose, scope and deadlines. One of four designed organizational operating models must be used for delegation of authorities.

This paper takes the dynamic scheduling of intelligent RGV as the research object and explores the problem of materiel machining of intelligent RGV for one and two procedures. In the process of establishing a materiel machining operation model for one procedure, firstly, the banker algorithm is used to provide a scheduling strategy for the RGV, dynamically predict the evolution process of the resource allocation process, and determine the order in which the CNC performs the task. Then, the non-preemptive least laxity first concept is introduced to improve the utilization rate of CNC and minimize the time for the computer machine tools CNC to wait for response. In order to simplify the calculation and improve the feasibility, based on the main idea of the banker algorithm, the evolution of the situation is only carried out in three levels, which makes the algorithm calculate moderately and has certain reference value for the prediction of the evolution process. Moreover, in the process of establishing a materiel machining operation model for two procedures, the bat algorithm is used to establish the model from the macroscopic perspective, and finally the dynamic scheduling strategy of RGV is obtained. In this paper, the dynamic scheduling strategy of intelligent RGV established for the materiel machining for one and two procedures provides a theoretical basis for the development of RGV dynamic scheduling strategy in the actual production process.

The rational allocation of chiller group plays an important role in the efficient operation of generating units. In this paper, the running characteristics of chiller group under full load are studied. Through the construction of the operation model of the chiller group, the relationship between the start and stop collocation and the operation characteristics of the unit group was explored, and the influence of the unit capacity configuration and the number of table number configuration on the running energy consumption characteristics was studied. The results showed that: the greater the difference of host capacity in the group, the lower the energy consumption under full load. In this example, the difference of energy consumption can reach 8%. At the same time, through the increase in the number of generating units, the difference in host capacity within the group had less impact on energy consumption at full load. For a unit group with the same host capacity, the more the number of units was configured, the lower the operating energy consumption. It provided theoretical support for the selection, collocation and operation management of chillers in practical projects.

This study is aimed at determining the optimal energy storage system (ESS) operation schedule to minimize the peak load on the feeder of a distribution network. To reduce the peak load, the feeder load needs to be predicted. However, a deterministic prediction is not reliable because it may contain errors. This study proposes the use of the prediction interval (PI) of the error estimated based on prior predictions. An algorithm is used to determine the optimal ESS schedule using the PI. To demonstrate the method’s validity, a case study is presented, where the proposed optimal ESS schedule determined based on PI reduces the peak load during network operations over a one-year period. The performance of the proposed method is superior to that of the conventional method which uses deterministic load prediction.

A fever clinic within a hospital plays a vital role in pandemic control because it serves as an outpost for pandemic discovery, monitoring and handling. As the outbreak of coronavirus disease 2019 (COVID-19) in Wuhan was gradually brought under control, the fever clinic in the West Campus of Wuhan Union Hospital introduced a new model for construction and management of temporary mobile isolation wards. A traditional battlefield hospital model was combined with pandemic control regulations, to build a complex of mobile isolation wards that used adaptive design and construction for medical operational, medical waste management and water drainage systems. The mobile isolation wards allowed for the sharing of medical resources with the fever clinic. This increased the capacity and efficiency of receiving, screening, triaging and isolation and observation of patients with fever. The innovative mobile isolation wards also controlled new sudden outbreaks of COVID-19. We document the adaptive design and construction model of the novel complex of mobile isolation wards and explain its characteristics, functions and use.

The bus system accounts for a significant part of trips in the city of Sao Paulo. However, in recent years the percentage of users has been falling concerning the growth modes such as individual transport and the new modes of transport on-demand based on applications. The loss of attractiveness is associated with users' negative perceptions of the quality of the service provided. One of the complaints is the recurring occurrences of buses that do not halt at the stop, even when the user signals his intention to embark or disembark. One way to address this problem would be to use technology like on-demand mobility services based on mobile applications. Although the idea itself seems to be simple, there is no report to date about a fixed route bus service that has implemented a bus hailing application that allows the user the possibility of requesting a bus to halt at a given stop. This paper proposes a new operation model of fixed-route buses that ensures the user requests fulfillment. The proposed model consists of functionalities that make the bus user visible to the operation, creating a more reliable connection between drivers and users. We evaluated the specified functionalities by a group of typical bus users in Sao Paulo, using a User Experience (UX) method. The evaluation clearly showed users' needs and desires regarding the features they would appreciate in the application. We collected clear evidence of the usefulness or not of the improvements suggested by users. Based on the study, we concluded that users agreed with the need to have greater control over their bus trips, in particular, to ensure that their intentions are adequately served and have a confirmation of the recognition of their requests. The study may become an interim solution that may be applied to existing bus services by taking them closer to on-demand services and MaaS (Mobility as a Service).

Background: Rapid recanalisation is important when treating ischaemic stroke patients. In Finland, the reorganisation of the prehospital emergency medical system and the establishment of emergency medicine as an independent speciality occurred some years ago. These reforms offered the opportunity to develop new prehospital and in-hospital pathways for stroke patients. Methods: In this retrospective study, we examined the immediate impact of implementing a new operating model in prehospital stroke care. We introduced a modified “load-and-go” model using a transformative learning process. We observed the immediate effects of the reorganisation by comparing prehospital time intervals three months before and three months after the reorganisation. Results: The new operating model was implemented using a transformative learning process. There was an immediate reduction of 35.1% from 21.4 to 13.9 minutes (P < 0.001) in the median on-scene time and of 18.2% from 52.7 to 43.1 minutes (P < 0.05) in the median total time, i.e. the time interval between the alarm from the dispatch centre to patient hand-over to ED. Conclusion: By using a transformative learning process in implementing a modified load-and-go operation model in the EMS, we could immediately reduce median on-scene time and median total time in the treatment of acute stroke patients. publishedVersion

The webpage steganography technique has been used for a covert communication method for various purposes in which a sender embeds a secret message into a plain webpage file like an HTML file by using various steganography methods. With human eyes, it is very difficult to distinguish between the original webpage (cover webpage) and the modified webpage with the secret data (stego webpage) because both are displayed alike in a web browser. In this approach, when two communicating entities want to share a secret message, a sender uploads a stego webpage to a web server or modifies an existing webpage in the web server by using a webpage steganography method, and then a receiver accesses the stego webpage to download and extract the embedded secret data from it. Meanwhile, according to our extensive survey, we observed that most webpage steganography methods focused on proposing or improving steganography algorithms but did not well address how to operate a stego webpage as time passes. However, if a stego webpage is used in a static way such that the stego webpage does not change and is constantly exposed to web clients until the sender removes it, such a static operation approach will limit or badly affect the hiding capacity and undetectability of a webpage steganography method. By this motivation, in this paper, we proposed a time-based dynamic operation model (TDOM) that improves the performance of existing webpage steganography methods in terms of hiding capacity and undetectability by dynamically replacing the stego webpage with other stego webpages or the original webpage. In addition, we designed two time-based dynamic operation algorithms (TDOA-C and TDOA-U), which improve the hiding capacity of existing methods and TDOA-U for improving the undetectability of existing methods, respectively. To validate our model and show the performance of our proposed algorithms, we conducted extensive comparative experiments and numerical analysis by implementing two webpage steganography methods with our TDOM (CCL with TDOA-C and COA with TDOA-C) and tested them in the web environment. According to our experiments and analysis, our proposed algorithms could significantly improve the hiding capacity and undetectability of two existing webpage steganography methods.

Given the increasingly worsening ecology issues in the lower Yellow River, the Xiaolangdi reservoir is chosen as the regulation and control target, and the single and multi-objective operation by ecology and power generation in the lower Yellow River is studied in this paper. This paper first proposes the following three indicators: the ecological elasticity coefficient (f1), the power generation elasticity coefficient (f2), and the ecological power generation profit and loss ratio (k). This paper then conducts a multi-target single dispatching study on ecology and power generation in the lower Yellow River. A genetic algorithm (GA) and an improved non-dominated genetic algorithm (NSGA-II) combining constraint processing and feasible space search techniques were used to solve the single-objective model with the largest power generation and the multi-objective optimal scheduling model considering both ecology and power generation. The calculation results show that: (1) the effectiveness of the NSGA-Ⅱcombined with constraint processing and feasible spatial search technology in reservoir dispatching is verified by an example, (2) compared with the operation model of maximizing power generation, the power generation of the target model was reduced by 0.87%, the ecological guarantee rate was increased by 18.75%, and the degree of the impact of ecological targets on the operating results was quantified, (3) in each typical year, the solution spatial distribution and dimensions of the single-target and multi-target models of change are represented by the Pareto-front curve, and a multi-objective operation plan is generated for decision makers to choose, (4) the f1, f2, and k indicators are selected to analyze the sensitivity of the five multi-objective plans and to quantify the interaction between ecological targets and power generation targets. Ultimately, this paper discusses the conversion relationship and finally recommends the best equilibrium solution in the multi-objective global equilibrium solution set. The results provide a decision-making basis for the multi-objective dispatching of the Xiaolangdi reservoir and have important practical significance for further improving the ecological health of the lower Yellow River.

The Future Circular Electron–Positron Collider (FCC-ee) is planned to be the world’s largest particle collider and a precision instrument to study the heaviest known particles. Achieving substantial physics results requires producing high amounts of integrated luminosity, which calls for sufficient machine availability. Although the operational availability of lepton colliders has been high, the increased complexity of the new infrastructure creates a challenge to maintain this. At the early stage of research, the main activity of an availability study should be to identify the causes that potentially have the most significant effect on downtime. This paper identifies critical systems of the FCC-ee based on available failure data. The paper further presents an operation model for the FCC-ee that can be used for assessing the effect of unavailability on overall performance. Special attention is given to systems with built-in redundancies as this design concept has been proven to increase accelerator availability.

The article deals with an approach to designing and implementing the operation model for the basic department in the education quality control system at higher education institutions. The approach refers to university structure within the framework of network interaction between university and school employees. The authors describe the designed structure and main components of the operation model of the university basic department and list organizational and pedagogical conditions for the implementation of the basic department model at university. The authors give a brief description and characterize the components required in the process of establishing the interaction: content-related, managerial and resulting. Within the framework of the model, the authors provide a brief personal characteristic of the head of the basic department that is essential and determines the key direction for development.The developed model has been implemented at the Institute of pedagogy and psychology of education of the State autonomous general education institution of higher education “Moscow City University” in cooperation with Moscow schools.

In this study, the sizing of a multi-energy system (MES) based on a multi-agent system (MAS) has been illustrated. In this model, the operation of the MES is completely decentralized and the sizing of the system has been done by adding an agent which takes the responsibility of the sizing optimization. The remarkable point is that each agent calculates the Net Present Cost (NPC) of its entities locally by getting the size of the elements from the optimizer agent and prevent agents from disclosing their private data. Then the optimizer agent updates the optimal size of elements in the multi-energy system by the calculated Net Present Cost which receives from other agents and selects the best answer from the available optimal answers based on the social welfare index. Our simulation result shows that the NPC of −196,161.88 $ is the best answer based on the assumed specifications. Given the fact that in the process of obtaining Net Present Costs the central agent is not involved and each agent gets the optimal Net Present Cost only by direct communication with its neighbor, this model eases the private ownership implementation in the sizing of the MESs.

The main efforts related to enterprise creation and development are aimed at improving efficiency of resource usage in the enterprise activities. Such problem can be successfully solved only if maximum efficiency is achieved at each stage of the conversion process. In turn, solution of this problem at each separate stage relates to creation of a substantiated structure of an object of functional conversion of source products into end products during the system operation. Such an object capable of functioning with maximum efficiency of resource usage was defined by default as a "functional system". By the example of a technological process of liquid heating, the problem of synthesizing a functional system of a conversion class with a portioned supply of products of directional effect was solved. In the course of synthesis, the task of ensuring possibility of interaction of the system objects during formation of the end product with required consumer qualities was solved at the first stage. Architecture of a module for identifying system operations and determining limit values of the effective control range was developed at the second stage of synthesis. A module linking the level of demand for the end products of the system with optimal control of its productivity was created at the third stage. Application of the proposed approach has enabled creation of a functional structure with a maximum number of degrees of control freedom. In turn, this solution has made it possible to form an optimal control trajectory depending on consumer demand for end products. The proposed solution enables use of the synthesized architecture for functional systems of a conversion class with a portioned supply of source products

A model for operating an energy hub-based multiple energy generation micro-grid is optimized using the demand response program. The optimized objective model is validated against energy demand of a residential building in Tehran, Iran. The mathematical model and optimal analysis of the proposed tri-generation micro-grid are implemented by using a real-world modelling and considering the constraints of the storage system, demand response program and the performance of the devices and the power and gas grids. The dynamic optimal operation model is prepared on the basis of the mixed integer linear programming on the subsequent day and is solved to minimize the costs of energy supply. To demonstrate the improvements, different scenarios are developed so that the renewable energy resources and storages are fed into the combined cool, heat and power system gradually. The results reveal that the inclusion of each element results in a significant improvement in the operational parameters of the micro energy grid. Scenario 1 includes a combined cool, heat and power system alone, Scenario 2 is supplemented with renewable wind and solar energy resources in addition to combined cool, heat and power system and Scenario 3 includes electrical, heat and cold storages in addition to combined cool, heat and power system and renewable energy sources. Scenario 4 is similar to Scenario 3 in terms of equipment, but the only difference lies in the use of the demand response program in the former. Total operational cost is 12.7% lower in Scenario 2 than in Scenario 1, 9.2% lower in Scenario 3 than in Scenario 2 and 8.6% lower in Scenario 4 than in Scenario 3. Practical application: An optimized operation method is prepared for combined cool, heat and power systems running in different operation modes in which renewable energy sources and storages are added to the combined cool, heat and power and the demand response program is applied. The results reveal that the cost of energy supply, including the cost of electricity, gas and pollutant emissions, is reduced and the qualitative parameters of the operation, including efficiency and reliability of building micro-grid, are increased. The proposed algorithm and the evaluation method will enable building operators to plan demand response activity on the residential building in Tehran, while this can be extended to other buildings too.

The net demand of distribution systems of renewable energy shows strong daily and seasonal patterns that may cause a loss of operation and constriction. Battery energy storage systems (BESS) allow peak load shaving and are used to enhance the reliability of distribution systems. In addition to the problem of an unbalanced net demand, there can be significant net demand fluctuation for different times and locations. To address this, mobile BESS (MBESS) can offer advantages over static BESS (SBESS) in operation flexibility, though may require higher engineering costs. In this study, an operation model was proposed to coordinate static and MBESS to improve overall system economic efficiency and reliability. On the basis of this model, a framework was proposed to optimally allocate MBESS/SBESS in a distribution system based on cost–benefit analysis. Using this approach, the optimal operation schedules for MBESS and SBESS can be simultaneously obtained. The proposed optimisation problem uses a new evolution algorithm, a natural aggregation algorithm. A case study on the IEEE test system successfully verified the effectiveness of the proposed approach for the optimal allocation of MBESS/SBESS in distribution systems.

For bulk AC/DC hybrid transmission systems with high wind power penetration, this paper presents a distributed dispatch approach to the security-constrained unit commitment (SCUC) problem. To fully use the flexible adjustment capability of the HVDC tie-line to promote inter-regional wind power accommodation, an operation model for the HVDC tie-line is presented. Then, a distributed SCUC approach based on the analytical target cascading technique is proposed, where the day-ahead SCUC problem is decomposed into an upper-level master problem and parallel sub-problems of lower-level regional dispatch. The master problem is in charge of determining the day-ahead transmission plan for the HVDC tie-line, and the lower-level dispatch centers independently solve their SCUC problems in parallel in accordance with the hierarchical and partitioned power scheduling mode. Simulations show that considering the flexible and controllable nature of the HVDC tie-line, the proposed distributed dispatch approach for bulk AC/DC hybrid systems has the advantages of promoting inter-regional wind power accommodation and improving the economics of the overall system operation while relieving the peak regulation pressure of the receiving-side system.

This study aims to study the online to offline (O2O) operation pattern of Chinese E-commerce and its features; analyze the current development and existing problems of Chinese O2O operation pattern; and explore the domestic O2O development layout of communities in Nanjing. Both qualitative and quantitative analyses are applied in this work. For the quantitative analysis, questionnaire was distributed to some consumers and communities randomly to study their current demands for O2O. 872 out of 900 questionnaire items were finally collected and used. For the qualitative analysis, in-depth interviews on enterprises in Suning, Jingdong and Guomei were conducted to find out the practical problems of community O2O model including their current situation, development trend as well as future development direction and possible measures. 30 interviewees are involved: 6 operators, 6 logistics staffsi¼Œ6 delivery staffs and 12 online shoppers. The findings of the study are; the current O2O operation model has attracted a range of consumers and enterprises because it is convenient and accessible, has diversified service categories, values customer evaluation and reduces time and distance to cut down cost, there are existing problems of Chinese O2O operation pattern in Nanjing communities: lack of trust for community O2O model , suspicious attitude towards enterprises certification, inadequate innovation of community O2O model ,difficulty in achieving community services standardization and the e-commerce platform has gone through three stages. As the representative of the first generation of e-commerce platform, Ali Taobao is featured by purely online virtual shopping platform. Represented by Tmall and Jiangdong, the second generation of e-commerce platform is characterized by the initial O2O model integrating virtual online shopping and physical stores. The third- generation e-commerce platform represented by Suning, Guomei, and e-commerce enterprises are characterized by community-based customers and standardization. Key words: O2O model, community, E-commerce, Nanjing.

In this paper, an analysis is made to the network/firepower integrated combat mode based on the development trend of future combat equipment and existing combat cases. Then, the system dynamics model of network/firepower integrated strike is established based on the mechanism of network reconnaissance/attack and firepower attack. The Attrition-Rate Coefficients model of network/firepower combat is established by studying the effectiveness evaluation method of network attack and firepower attack. The Lanchester model of network/firepower integrated confrontation covering normal nodes, infected nodes and all infected nodes is established. In order to study the dynamic, uncertain network counter process, a type of the vibration network attack is introduced to Lanchester equation and its effectiveness in network attack process is discussed by means of the simulation results.

The existing dynamical fermentation models only reveal approximate macroscopic properties involving no internal mechanism, while dynamic metabolic flux analysis (DMFA) provides internal microscopic dynamic features, but without regulation from external operation conditions. This is the first attempt to bridge the mapping between macro operation variables and micro metabolic fluxes. Based on the macro-micro mapping relationship, a new operation model was constructed, which can use macro operation variables to regulate micro metabolic fluxes. Firstly, metabolic network was analyzed based on DMFA to derive flux distribution. Next, the fluxes defined as outputs were related to macro operation variables to establish the operation model. The complexity of cellular growth and diversity of flux distribution led to nonlinear and multi-stage characteristics of the mapping relationship, and thus a multi-model modeling method was employed as key algorithm. Finally, a simulation and a lab-scale experiment were conducted to demonstrate the application of the proposed method.

Hydropower plays an extremely important role in the energy market with the increasing energy demand. The intra-annual runoff distribution (IARD) in the hydrological year has an important impact on the energy generation of cascade hydropower plants (CHP). This study evaluated the non-uniformity of IARD of the Datong River basin (DRB) in the hydrological year. The optimal operation model of CHP was constructed based on the genetic algorithm to investigate the impact of the non-uniformity of IARD on the energy generation of CHP. This study shows the following: 1) The observed runoff series has a decreasing trend, the non-uniformity of IARD has an increasing trend overall. 2) The energy generation of CHP shows a weak decreasing trend affected by the decrease of runoff and the increase of non-uniformity. 3) With or without water diversion, the CHP energy generation decreases with the increase of non-uniformity of IARD. 4) The difference of energy generation of CHP between consideration or not the water diversion is about 400 GWh when the inflow frequency is less than 50%. 5) The impact of non-uniformity of IARD on energy generation will be greater with the inflow increasing. This study can provide theoretical support for the water resources management and operation of CHP.

Flexible Load (FL) of electricity, heat and gas can improve the operation economy, flexibility and reliability of PIES. Aiming at the uncertainty of FL in the actual operation of the park integrated energy system (PIES), an optimal operation model of PIES with uncertainty of FL is proposed. Firstly, the uncertainty models of shiftable electric load and transferable load response are established, respectively. And then an adjustable heat load response model considering the uncertainty of solar radiation intensity is established. On this basis, an optimal operation model of PIES considering the uncertainty of the FL with the goal of maximizing the total revenue is constructed and is solved by the enhanced-interval linear programming method. Simulation indicate that FL can improve the operating economy of PIES and renewable energy consumption.

With the development of smart grid and energy internet, energy storage will play an important role in maintaining the power balance and providing frequency regulation in future power system. Consequently, energy storage faces a trade-off problem between the energy market and frequency regulation market. In this work, an operation model and strategy of energy storage to provide frequency regulation is proposed. Taking lithium battery as an example of energy storage, its technical feasibility to provide frequency regulation is firstly discussed. Then, a day-ahead energy market model in the power system is constructed to calculate the revenue of lithium battery. Finally, the operation strategy of lithium battery to provide secondary frequency regulation (namely AGC) is proposed based on the model of opportunity cost. Case study is conducted on a modified IEEE 6-bus system. It shows that the reduced marginal revenue of lithium battery in the energy market increases with the growth of its declared capacity for frequency regulation. Consequently, the optimal declared frequency regulation capacity for lithium battery is the amount, at which the reduced marginal revenue in the energy market is equal to the compensation price of frequency regulation.