Flexible Service Provision Research Articles

Traffic Prediction-Based VNF Auto-Scaling and Deployment Mechanism for Flexible and Elastic Service Provision

Traffic Prediction-Based VNF Auto-Scaling and Deployment Mechanism for Flexible and Elastic Service Provision

Local Energy Community to Support Hydrogen Production and Network Flexibility

This paper deals with the optimal scheduling of the resources of a renewable energy community, whose coordination is aimed at providing flexibility services to the electrical distribution network. The available resources are renewable generation units, battery energy storage systems, dispatchable loads, and power-to-hydrogen systems. The main purposes behind the proposed strategy are enhancement of self-consumption and hydrogen production from local resources and the maximization of the economic benefits derived from both the selling of hydrogen and the subsidies given to the community for the shared energy. The proposed approach is formulated as an economic problem accounting for the perspectives of both community members and the distribution system operator. In more detail, a mixed-integer constrained non-linear optimization problem is formulated. Technical constraints related to the resources and the power flows in the electrical grid are considered. Numerical applications allow for verifying the effectiveness of the procedure. The results show that it is possible to increase self-consumption and the production of green hydrogen while providing flexibility services through the exploitation of community resources in terms of active and reactive power support. More specifically, the application of the proposed strategy to different case studies showed that daily revenues of up to EUR 1000 for each MW of renewable energy generation installed can be obtained. This value includes the benefit obtained thanks to the provision of flexibility services, which contribute about 58% of the total.

Enabling Efficient Spatio-Temporal GPU Sharing for Network Function Virtualization

By leveraging standard IT virtualization technology and Commercial-Off-The-Shelf (COTS) servers, Network Function Virtualization (NFV) decouples network functions from proprietary hardware devices for flexible service provisioning. But the potential of NFV is significantly limited by its performance inefficiency. With the unparalleled advantages of multi-core parallelism and high memory bandwidth, Graphics Processing Units (GPUs) are regarded as a promising way to accelerate Virtualized Network Functions (VNF). However, the special architecture of GPU brings new challenges to task scheduling and resource allocation. To this end, we propose a <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</b> PU <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</b> riented <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</b> patio- <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</b> emporal sharing framework for NFV called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Gost</i> , aiming for GPU based VNF performance promotion. The execution order and GPU resource allocation (i.e., the number of threads) are considered in task scheduling to minimize the end-to-end latency for VNF flows. First, we formulate the task scheduling problem into a nonlinear programming form, and then transform it into an equivalent Integer Linear Programming (ILP) form.The problem is proved as NP-hard. We customize the classical list scheduling algorithm and propose a List Scheduling based Spatio-Temporal GPU sharing strategy (LSSTG), whose achievable worst-case performance is also formally analyzed. We practically implement <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Gost</i> prototype, based on which extensive experiments verify the high performance efficiency of LSSTG compared to state-of-the-art in terms of latency and throughput.

SFC-based multi-domain service customization and deployment

In order to satisfy diversified service demands, future networks are expected to provide higher quality network services, especially in 5G scenarios. Network Function Virtualization (NFV) is a promising architecture to achieve flexible service provisioning by introducing Service Function Chain (SFC) technology. With explosive expansion of network devices and end users, the complex multi-domain network environment and personalized service demands of different users pose serious challenges to efficient service provisioning. To this end, this paper presents a novel SFC-based Multi-domain Service Customization and Deployment framework, MSCD, by blending merits of Software Defined Networking (SDN) and NFV technologies. MSCD framework can automatically customize multi-domain network services based on users’ personalized service preferences, and deploy them in multi-domain networks, to provide customizable multi-domain services for different users. Taking into account user personalized service preferences, resource allocation and VNF dependency constraints, the multi-domain service customization and deployment problem is mathematically formulated as an optimization model with the target of service satisfaction degree maximization. Furthermore, a Greedy strategy based Heuristic Service Customization and dePloyment (GHSCP) algorithm is proposed to customize and deploy the multi-domain services efficiently. Simulation results demonstrate that the proposed GHSCP algorithm is efficient and outperforms comparison algorithms in terms of service acceptance ratio and service satisfaction degree.

On-demand energy flexibility market via smart contracts to help reduce balancing costs in Great Britain

The large deployment of renewable generation required to reach net-zero carbon emission requires significant investments in transmission network infrastructure to reduce grid congestion, as well as costly investments in dispatchable assets to manage the intermittency of renewable energy. The provision of flexibility services to system operators represents an additional method that could help solve these issues. However, this requires the engagement of a large number of small users, such as households and small commercial firms, that usually cannot directly participate in electricity markets due to their limited size. Blockchain technologies leveraging smart contracts can provide an autonomous, cost-saving and transparent tool to help engage these users in the provision of flexibility services to the grid. The aim of this paper is to design a new market layer for the on-demand provision of flexibility services by using smart contracts fully integrated with existing national-scale electricity markets. We demonstrate how this model can co-exist with the current electricity market architecture in Great Britain (GB), providing a whole-system least-cost solution to solve grid congestion and energy imbalances. Simulations based on a high-fidelity network of GB highlight the potential benefit that the proposed approach could create at the national scale.

Co-simulation framework for the provision of flexibility services for DSO using electric heating systems

Co-simulation framework for the provision of flexibility services for DSO using electric heating systems

Predictors of Access to Early Support in Families of Children with Suspected or Diagnosed Developmental Disabilities in the United Kingdom

This study examined predictors of access to early support amongst families of 0-6-year-old children with suspected or diagnosed developmental disabilities in the United Kingdom. Using survey data from 673 families, multiple regression models were fitted for three outcomes: intervention access, access to early support sources, and unmet need for early support sources. Developmental disability diagnosis and caregiver educational level were associated with intervention access and early support access. Early support access was also associated with child physical health, adaptive skills, caregiver ethnicity, informal support, and statutory statement of special educational needs. Unmet need for early support was associated with economic deprivation, the number of household caregivers, and informal support. Multiple factors influence access to early support. Key implications include enhancing processes for formal identification of need, addressing socioeconomic disparities (e.g., reducing inequalities, increasing funding for services), and providing more accessible services (e.g., coordinating support across services, flexible service provision).

Improving residents’ wellbeing in senior citizen homes with more individualized food services

Currently, food services in Swiss senior citizen homes heavily depend on the presence and working hours of human resources. For most residents, there is currently no possibility to eat according to their individual needs or preferences. However, trends like flexible catering, the reduction of the importance of lunch as main meal of the day or the “snackification” will influence service delivery in senior citizen homes in the future. At the same time, staff shortage and decreasing financial means force institutions to find new service designs. The goal was to find out how the wellbeing of residents in senior citizen homes can be improved by providing more individualized food services. Based on literature, a mixed-method research approach was chosen, combining expert interviews and a survey amongst management and staff representatives of Swiss senior citizen homes. It becomes clear that a more flexible food service provision needs to be thought in a holistic context encompassing the whole organisation, including not only hospitality staff but also management and care professionals.

The energy flexibility divide: An analysis of whether energy flexibility could help reduce deprivation in Great Britain

The provision of energy flexibility services (such as shifting consumption) to electricity systems is becoming increasingly valuable, and can offer additional income for households. Here, we show how the locational distribution of flexibility impacts its value, and whether this could help reduce deprivation in Great Britain. Geospatial analysis shows that nearly 90 % of people (1.3 million) living in the most deprived areas of Greater London can offer high-value flexibility. This could help improve their economic condition, provided that the adoption of appropriate appliances (such as demand response devices) is incentivised, e.g. through government's spatially targeted incentive schemes. The results show that the provision of flexibility could help reduce deprivation in several regions, including Scotland, Greater London, and Yorkshire. By contrast, other areas such as North and North-East England tend to offer lower-value flexibility, and therefore the benefit would be smaller. A flexibility-adjusted deprivation index is proposed to highlight regions where providing flexibility may most help reduce deprivation.

Dynamic Computation Offloading with Deep Reinforcement Learning in Edge Network

With the booming proliferation of user requests in the Internet of Things (IoT) network, Edge Computing (EC) is emerging as a promising paradigm for the provision of flexible and reliable services. Considering the resource constraints of IoT devices, for some delay-aware user requests, a heavy-workload IoT device may not respond on time. EC has sparked a popular wave of offloading user requests to edge servers at the edge of the network. The orchestration of user-requested offloading schemes creates a remarkable challenge regarding the delay in user requests and the energy consumption of IoT devices in edge networks. To solve this challenge, we propose a dynamic computation offloading strategy consisting of the following: (i) we propose the concept of intermediate nodes, which can minimize the delay in user requests and the energy consumption of the current tasks handled by IoT devices by dynamically combining task-offloading and service migration strategies; (ii) based on the workload of the current network, the intermediate node selection problem is modeled as a multi-dimensional Markov Decision Process (MDP) space, and a deep reinforcement learning algorithm is implemented to reduce the large MDP space and make a fast decision. Experimental results show that this strategy is superior to the existing baseline methods to reduce delays in user requests and the energy consumption of IoT devices.

Towards Metaverse with Diversified Applications: Service Native Architecture

With the advancement of science and technology, Metaverse will empower the entity economy and social development, and stimulate the development potential of industries such as smart city. The current chimney-style application creation process is cumbersome, which cannot support the application diversification and efficient, flexible and open service provision methods, so it cannot meet the needs of the rapid development of the Metaverse. By introducing a service engine layer that encapsulates basic service capabilities, this research proposes a Metaverse application architecture based on service native, which has characteristics of function scalability, orchestration automation, system openness, full-type access, etc. The basic service capabilities based on this architecture can support diverse needs of Metaverse applications.

Optimal Scheduling of Controllable Resources in Energy Communities: An Overview of the Optimization Approaches

In recent years, there has been a growing interest in the study of energy communities. This new definition refers to a community sharing energy resources of different types to meet its needs and reduce the associated costs. Optimization is one of the most widely used techniques for scheduling the operation of an energy community. In this study, we extensively reviewed the mathematical models used depending on the objectives and constraints considered. The models were also classified according to whether they address uncertainty and the inclusion of flexibility constraints. The main contribution of this study is the analysis of the most recent research on the mathematical formulation of optimization models for optimal scheduling of resources in energy communities. The results show that the most commonly used objectives are profit maximization and cost minimization. Additionally, in almost all cases, photovoltaic generation is one of the main energy sources. Electricity prices, renewable generation, and energy demand are sources of uncertainty that have been modeled using stochastic and robust optimization. Flexibility services using demand response are often modeled using interruptible loads and shiftable loads. There is still considerable room for further research on the distribution of benefits among the participants of the energy community and the provision of flexibility services to the electricity grid.

Pricing and remunerating electricity storage flexibility using virtual links

Ambitious renewable portfolio standards motivate the mass deployment of energy storage resources (ESR) as sources of flexibility. As such, the design of electricity markets that properly remunerate the provision of flexibility services by ESRs is under active development. In this paper, we propose a new market clearing framework that incorporates ESR systems. Compared to existing market designs, our approach models ESR systems using the concept of virtual links (VLs), which capture the transfer/shift of power across time. The VL representation reveals economic incentives available for ESR operations and sheds light into how electricity markets should remunerate ESRs. Our framework also allows us to explore the role of ESR physical parameters on market behavior; specifically, we show that, while energy and power capacity defines the amount of flexibility each ESR can provide, charge/discharge efficiencies play a fundamental role in ESR remuneration and in the ability of the power grid to mitigate market price volatility. The new market design is also computationally attractive in that it is a linear program and thus avoids mixed-integer formulations and formulations with complementarity constraints (used in current designs to capture binary charge/discharge logic). We use our market framework to analyze the interplay between ESRs and market operators and to provide insights into optimal deployment strategies for ESRs in power grids.

The Strategies for Increasing Grid-Integrated Share of Renewable Energy with Energy Storage and Existing Coal Fired Power Generation in China

The growing share of renewable energies needs more flexible services to balance their intermittency and variance. The existing coal fired units and electrical energy storage (EES) systems may play an important role in delivering flexible services. The value of their flexibility services, along with the value of renewable energies, has to be analyzed from the perspective of the power system, in which the capacity costs and operation costs of renewable energy power units, EES systems, and thermal power generation units have to be taken into consideration. An optimal model is built to analyze the renewable energy integration and the flexibility services delivered by the EES systems and thermal power units in a power system. Taking the existing thermal power units and EES systems in North China Power Grid as an instance, the overall cost of the grid is examined for the penetration of renewable energies and flexible service provision. The results show that the growing shares of renewable energies are affected by their capacity credits and flexibility sources in the grid, and that the potential of thermal power units to provide flexible services will be reduced due to the replacement of renewable energies for thermal power generation. The results also indicate that the thermal units may be dispatched to have priority to delivering flexible services for the renewable energy integration, and that the curtailment of renewable energies may be regarded as one type of flexible service. According to these results, policy and strategy recommendations are put forward to weigh the role of existing coal-fired units and EES systems in providing flexible services, and to improve their compensation mechanism and their coordination.

START-online: acceptability and feasibility of an online intervention for carers of people living with dementia

BackgroundWith increasing numbers of people living with dementia relying on family to care for them at home, there is an urgent need for practical and evidence-based programs to support carers in maintaining their mental health and well-being. The objective of this study was to evaluate the acceptability and feasibility of a modified STrAtegies for RelaTives (START) program delivered online (START-online).MethodA mixed-methods non-blinded evaluation of START-online (using Zoom as videoconferencing platform) for acceptability and feasibility (completion rates and qualitative feedback through surveys and focus groups) and quantitative evaluation. This occurred at the National Ageing Research Institute, in metropolitan Victoria, Australia.ResultsTwenty-nine eligible carers were referred, 20 (70%) consented to the study. Of these, 16 (80%) completed all 8 sessions, 2 completed only 3 sessions, and 2 withdrew. Carers’ qualitative feedback indicated that the therapist interaction was valued, content and online delivery of the program was acceptable. Feedback was mixed on the appropriate stage of caring.ConclusionSTART-online was feasible and acceptable for carers, including those living outside of metropolitan areas who might otherwise be unable to access face-to-face programs. With the recent COVID-19 pandemic necessitating social distancing to avoid infection, interventions such as this one have increasing relevance in the provision of flexible services.

Risky business: Impact of outcomes-based contracting on nongovernment out-of-home-care services

This article examines the impacts of commercialised contracting in helping or hindering policy objectives relating to Out-of-Home Care (OOHC) reforms in one Australian jurisdiction, New South Wales (NSW). Its particular focus is the impact of outcomes-based contracting on nongovernment organisations rendering foster and residential care services. Though contracting has long been present in government NGO funding models, of particular concern is the impact of the commercialisation of OOHC contracts. The author argues that this shift has had a detrimental impact on the nongovernment sector’s capacity to provide quality services to children and families. Contextualising commercialisation within the narrative of risk, it argues that political and ideological shifts in government policy and action reflect a strategy that absolves the government of the risks inherent in reforming the OOHC system or of managing OOHC contracts, a process that also minimises government accountability. The article presents evidence to show that reforms to the OOHC system in NSW have failed to achieve their intended outcomes partly due to the challenges to the nongovernment sector and its relationship with the government brought by contracting arrangements. As reported in other welfare systems internationally, it shows that a narrow conceptualisation of outcomes in conjunction with an emphasis on performance measures can detract from flexible and innovative service provision that is responsive to the needs of individual clients. The article adds to international evidence relating to the efficacy of contracting of services to meet policy objectives and identifies areas of management improvement.

HYFLEX ORGANIZATION OF FOREIGN LANGUAGE TEACHING: SPECIALTIES 013 «PRIMARY EDUCATION» AND 012 «PRESCHOOL EDUCATION»

The article is devoted to the theoretical aspects of the HyFlex organization of foreign language learning for students of specialties 013 «Primary Education» and 012 «Preschool Education». The essence of the basic concepts «HyFlex training» and «HyFlex organization of foreign language training» have been clarified. Based on the analysis of the scientific and pedagogical literature, the term «HyFlex learning» is defined as a form of learning in which one part of the students is present (physically) in the auditorium, while the other simultaneously participates in the learning process remotely (online). The concept «Hyflex organization of foreign language training for students of specialties 013 «Primary Education» and 012 «Preschool Education» is considered as a purposeful, structured set of actions of subjects of the educational process (lecturer and students) aimed at flexible provision and receipt of educational services with the purpose of achieving the results of foreign language training, which are determined by the educational and professional programs of the specified specialties. HyFlex foreign language training is aimed at expanding, improving and enriching the flexibility of education seekers in the content of their foreign language training. With the help of a complex of theoretical methods (analysis, synthesis, comparison, generalization, specification), the HyFlex technology of foreign language learning for students of specialties 013 «Primary Education» and 012 «Preschool Education» was determined. Its purpose is to create favorable conditions so that students could to master a foreign language effectively, taking into account the objective risks of nowadays (pandemic, war, etc.). The tasks and outcomes of the Hyflex technology of foreign language learning for students of specialties 013 «Primary Education» and 012 «Preschool Education» are correlated with the Educational and Professional Programs of the specified specialties. The structure and logic of the Hyflex organization of foreign language learning for students of specialties 013 «Primary Education» and 012 «Preschool Education» was determined, which includes the following stages (components): organizational-target, activity-procedural and evaluation-refective. The authors have characterized each structural component of the Hyflex foreign language learning technology in short.

Cost-minimized virtual elastic optical network provisioning with guaranteed QoS

Network virtualization is important for elastic optical networks (EONs) because of more flexible service provisioning. To ensure guaranteed quality of service (QoS) for each virtual elastic optical network (VEON), clients usually request network resources from a network operator based on their bandwidth requirements predicted from historical traffic demands. However, this may not be efficient as the actual traffic demands of users always fluctuate. To tackle this, we propose a new VEON service provisioning scheme, called SATP, which consists of three stages, i.e., spectrum assignment (SA), spectrum trading (ST), and spectrum purchasing (SP). Unlike conventional once-for-all VEON service provisioning approaches, the SATP scheme first allocates spectrum resources to VEONs according to their predicted bandwidth requirements with a satisfaction ratio α (0 < α < 1). Then, to minimize service degradation on VEONs which are short of assigned spectra for their peak traffic periods, the scheme allows VEONs to trade spectra with each other according to their actual bandwidth requirements. Finally, it allows VEON clients to purchase extra spectrum resources from a network operator if the spectrum resources are still insufficient. To optimize this entire process, we formulate the problem as a mixed integer linear programming (MILP) model and also develop efficient heuristic algorithms for each stage to handle large test scenarios. Simulations are conducted under different test conditions for both static and dynamic traffic demand scenarios. Results show that the proposed SATP scheme is efficient and can achieve significant performance improvement under both static and dynamic scenarios.

The perspectives of community-based practitioners on preventing baby removals : Addressing legitimate and illegitimate factors

The removal of babies at or near birth is a significant health, ethical, personal and social justice issue affecting many families globally. While sometimes required, it can carry a risk of harm for babies, their families and communities, as well as refracting social inequities relating to class, gender, ethnicity, location and disability. This article reports the qualitative perceptions of community-based social workers in Aotearoa New Zealand about how to prevent baby removals. Preventing removal requires attention to the factors impacting on parenting capacity as well as factors relating to the decision-making ecology environment of child protection systems. Practitioner attributes of a whānau centred practice orientation, a focus on capability and advocacy, values of respect, and recognition of commitment to children, contributed to reducing the escalation of child protection intervention. An ability to mediate between the world of the child protection agency and the family, and recognising emotional responses were practitioner skills that also contributed to prevention. Organisational factors that helped prevent removal were the provision of flexible, intensive, holistic and accessible services; strategic service coordination between statutory and community-based services; and support offered early in the pregnancy by parenting-experienced practitioners. Family issues of poverty, drug use and intimate partner violence were exacerbated in families who were socially isolated, requiring community and social network development. In addition to these preventive factors, there were also also decision ecology factors that increased the risk of removal. These included organisational factors such as poor relationships between the statutory agency and community agencies, lack of the right types of service provision, and the tendency for reliance on recorded family histories in assessment leading to superficial and risk -averse judgements. Unrealistic expectations and changing expectations further estranged families from services and reduced the chances of avoiding removal. These perverse system factors were especially pernicious for those populations with heightened chances of system contact, particularly Māori and people living in poverty, exacerbating institutionalised racism. Implications are critically analysed with reference to the concept of legitimacy.

A new real time hydraulic test platform dedicated to Ancillary Services

Characterization of Hydraulic turbines, storage pumps and pump-turbines is a well-known process formalized in the IEC60193 standard. Test platforms ensure the acceptance of hydraulic design with respect to hydraulic transpositions such as efficiency, range of operation, cavitation, stability etc. These test platforms only focuses on the static operation of a turbine. The HydroPHIL platform - which stands for Power Hardware In the Loop for Hydro-electrical conversion - focuses on studying transients operations of Pump Storage Plants. It includes a fully operational scale model of a hydraulic units from water to wire. The scaled model interacts with a real time grid emulator and a real time penstock emulator. The test platform allows the simulation of technologies in relevant environment related to three main topics of investigation: a) system behavior study, whether it is solicited by the grid (frequency or voltage dips, etc.) or the piping system (water hammer, etc.) b) new conversion technologies with real electrical components (such as variable speed PSP), and c) development of new control strategies to improve provision of ancillary services and other flexibility services. This paper presents the platform architecture and features.