Centralized Ones Research Articles

Design and installation of a novel multi-point measurement system for a renewable energy grid

New power generation systems will be characterized by multiple small-scale units, integrating non conventional or renewable sources, such as wind turbines, photovoltaic power plants or even hydrogen generation and storage. Monitoring this kind of installations is of vital importance for security of supply and efficiency issues. The integration of these energy sources with the actual centralized ones involves great challenges for engineers to correctly plan the grid without any problem of stability. Therefore, successful implementations of smart electrical networks require the development of robust systems of analysis for electrical parameters. This paper shows a multipoint measurement system, installed in a relevant renewable-supplied technology park, ready to monitor all power quality parameters and their influence into the distribution grid. Important results will be shown applied to the existent power quality (PQ) at the technology park.

Spread Is Better: Suitability for Climate Neutrality of Italian Urban Systems

In light of the challenges required by the European Green Deal policies concerning the achievement of climate neutrality by 2050, this paper analyses the suitability of different Italian urban systems for energy consumption and CO2 emission reduction. In anthropised territories, there are strong relationships between energy consumption, climate-changing emissions and settlement patterns. Lands considered low could increase their rating because they have far greater environmental, energy and land resources than more pivotal ones. After an Italian-scale overview of the ecosystem capacities, this paper develops a detailed study of three exemplary areas: the northeast, the northwest, and the central-west coast. The analysis uses Burkhard’s matrix for ecosystem values and the energy consumption 2021 report of the National Energy Authority. The first finding is that the northeast region, characterised by spread and rarefied urbanisation, has a peculiar suitability for climate neutrality. In the results, spread territories perform much better than centralised ones. The coexistence of little urban cores, space for vegetation and a widespread water network promotes synergies for enhancing an ecosystem approach to land design.

Peer-To-Peer Networking for Content Distribution and Sharing

Peer-to-peer networking, often known as P2P, enables distributed and decentralized  types of processing, resource sharing, and communication. It has recently proven itself to be a reliable and adaptable technical instrument. Peer-to-peer networking, often known as P2P networking, eliminates the need for centralized  servers or other middlemen by allowing nodes in a network to communicate and share resources directly with one another. This has a number of advantageous effects, such as improved fault tolerance and resistance, improved privacy and security, and a simplified method of resource sharing. Peer-to-peer (P2P) networking has several potential uses outside of distributed computing and social networking, including content delivery and file sharing. Decentralized  P2P networks could be faster, more effective, and more customizable than centralized  ones. This is possible because to the usage of distributed and decentralized  networks. P2P networking, however, presents several difficulties that must be solved. Among these are the possibility of security difficulties, the requirement for efficient administration and management, and the risk of coming across legal and regulatory challenges. Despite the problems mentioned above, P2P networking is anticipated to play a significant role in the development of new technologies and applications. Peer-to-peer networking may become even more effective, safe, and versatile in the not-too-distant future because to advancements in P2P protocols, algorithms, and applications. P2P networking is a technology that should thus be given attention and funding because of its potential to revolutionise how we communicate with one another.

Resilience assessment of centralized and distributed food systems.

Resilience, defined as the ability of a system to adapt in the presence of a disruptive event, has been of great interest with food systems for some time now. The goal of this research was to build understanding about resilient food systems that will withstand and recover from disruptions in a way that ensures a sufficient supply of food for all. In large, developed countries such as the USA and Canada, the food supply chain relies on a complex web of interconnected systems, such as water and energy systems, and food production and distribution are still very labor-intensive. Thanks to economies of scale and effective use of limited resources, potential cost savings support a push towards a more centralized system. However, distributed systems tend to be more resilient. Although distributed production systems may not be economically justifiable than centralized ones, they may provide a more resilient alternative. This study focused on the supply-side aspects of the food system and the food system's water, energy, and workforce disruptions to be considered for the resilience assessment for the USA, with an example for the state of Texas. After the degree of centralization (DoC) was calculated, the resilience of a food system was measured. Next, the relationship between labor intensity and production of six major food groups was formulated. The example for Texas showed that the decentralization of food systems will improve their resilience in responding to energy and water disruptions. A 40 percent reduction in water supply could decrease the food system performance by 28%. A negative correlation was found between the resilience and DoC for energy disruption scenarios. A 40 percent reduction in energy supply could decrease the food system performance by 34%. In contrast, achieving a more resilient food system in responding to labor shortage supports a push towards a more centralized system the decentralization of food systems can in fact, improve their resilience in responding to disruptions in the energy and water inputs. In contrast, achieving a more resilient food system in responding to labor shortage supports a push towards a more centralized system.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12571-022-01321-9.

TSCH Multiflow Scheduling with QoS Guarantees: A Comparison of SDN with Common Schedulers

Industrial Wireless Sensor Networks (IWSN) are becoming increasingly popular in production environments due to their ease of deployment, low cost and energy efficiency. However, the complexity and accuracy demanded by these environments requires that IWSN implement quality of service mechanisms that allow them to operate with high determinism. For this reason, the IEEE 802.15.4e standard incorporates the Time Slotted Channel Hopping (TSCH) protocol which reduces interference and increases the reliability of transmissions. This standard does not specify how time resources are allocated in TSCH scheduling, leading to multiple scheduling solutions. Schedulers can be classified as autonomous, distributed and centralised. The first two have prevailed over the centralised ones because they do not require high signalling, along with the advantages of ease of deployment and high performance. However, the increased QoS requirements and the diversity of traffic flows that circulate through the network in today’s Industry 4.0 environment require strict, dynamic control to guarantee parameters such as delay, packet loss and deadline, independently for each flow. That cannot always be achieved with distributed or autonomous schedulers. For this reason, it is necessary to use centralised protocols with a disruptive approach, such as Software Defined Networks (SDN). In these, not only is the control of the MAC layer centralised, but all the decisions of the nodes that make up the network are configured by the controller based on a global vision of the topology and resources, which allows optimal decisions to be made. In this work, a comparative analysis is made through simulation and a testbed of the different schedulers to demonstrate the benefits of a fully centralized approach such as SDN. The results obtained show that with SDN it is possible to simplify the management of multiple flows, without the problems of centralised schedulers. SDN maintains the Packet Delivery Ratio (PDR) levels of other distributed solutions, but in addition, it achieves greater determinism with bounded end-to-end delays and Deadline Satisfaction Ratio (DSR) at the cost of increased power consumption.

Power Allocation Strategy Based on Decentralized Convex Optimization in Modular Fuel Cell Systems for Vehicular Applications

Recently, modular powertrains have come under attentions in fuel cell vehicles to increase the reliability and efficiency of the system. However, modularity consists of hardware and software, and the existing powertrains only deal with the hardware side. To benefit from the full potential of modularity, the software side, which is related to the design of a suitable decentralized power allocation strategy (PAS), also needs to be taken into consideration. In the present study, a novel decentralized convex optimization (DCO) framework based on auxiliary problem principle (APP) is suggested to solve a multi-objective PAS problem in a modular fuel cell vehicle (MFCV). The suggested decentralized APP (D-APP) is leveraged for accelerating the computational time of solving the complex problem. Moreover, it enhances the durability and the robustness of the modular powertrain system as it can deal with the malfunction of the power sources. Herein, the operational principle of the suggested D-APP for the PAS problem is elaborated. Moreover, a small-scale test bench based on a light-duty electric vehicle is developed and several simulations and experimental validations are performed to verify the advantages of the proposed strategy compared to the existing centralized ones.

Децентрализация кризиса, слабости и ответственности

Crises frequently weaken subnational governments but in some cases they lead to greater decentralization. Does this decentralization, however, support the search for optimal crisis response strategies? Generally speaking there are several arguments, which suggest that decentralized systems will manage crises better than centralized ones. This article, however, considers two scenarios (decentralization of weakness and decentralization of responsibility) where the apparently increasing autonomy of subnational governments leads to important problems. Decentralization of weakness emerges when the central government for certain reasons refuses to actively implement an anti-crisis policy. Under these conditions, regional measures, while to some extent compensating the inactivity of the central government, create a number of other problems - that of external effects, possible ideologization of politics and insufficient use of expert knowledge. Decentralization of responsibility emerges when regions accept responsibility for implementing anti-crisis measures, but the center keeps control over resources - thus, regions have to focus on competing for central financing. For the modern Russia, the risks of these two scenarios are substantial.

Performance assessment of water reuse strategies using integrated framework of urban water metabolism and water-energy-pollution nexus

This paper evaluates the metabolism-based performance of a number of centralised and decentralised water reuse strategies and their impact on integrated urban water systems (UWS) based on the nexus of water-energy-pollution. The performance assessment is based on a comprehensive and quantitative framework of urban water metabolism developed for integrated UWS over a long-term planning horizon. UWS performance is quantified based on the tracking down of mass balance flows/fluxes of water, energy, materials, costs, pollutants, and other environmental impacts using the WaterMet2 tool. The assessment framework is defined as a set of key performance indicators (KPIs) within the context of the water-energy-pollution nexus. The strategies comprise six decentralised water reuse configurations (greywater or domestic wastewater) and three centralised ones, all within three proportions of adoption by domestic users (i.e. 20, 50, and 100%). This methodology was demonstrated in the real-world case study of San Francisco del Rincon and Purisima del Rincon cities in Mexico. The results indicate that decentralised water reuse strategies using domestic wastewater can provide the best performance in the UWS with respect to water conservation, green house gas (GHG) emissions, and eutrophication indicators, while energy saving is almost negligible. On the other hand, centralised strategies can achieve the best performance for energy saving among the water reuse strategies. The results also show metabolism performance assessment in a complex system such as integrated UWS can reveal the magnitude of the interactions between the nexus elements (i.e. water, energy, and pollution). In addition, it can also reveal any unexpected influences of these elements that might exist between the UWS components and overall system.

The collaborative multi-level lot-sizing problem with cost synergies

Collaborative operations planning is a key element of modern supply chains. We introduce the collaborative multi-level lot-sizing problem with cost synergies. This arises if producers can realise reductions of their costs by providing more than one product in a specific time horizon. Since producers are typically not willing to reveal critical information, we propose a decentralised mechanism, where producers do not have to reveal their individual items costs. Additionally, a Genetic Algorithms-based centralised approach is developed, which we use for benchmarking. Our study shows that this approach comes very close to the a central plan, while in the decentralised one no critical information has to be shared. We compare the results to a myopic upstream planning approach, and show that these results are almost 12% worse than the centralised ones. All solution approaches are assessed on available test instances for problems without cost synergies. For the biggest available instances, the proposed centralised mechanism improves the best known solutions on average by 10.8%. The proposed decentralised mechanism can be applied to other problem classes, where collaborative decision makers aim for good plans under incomplete information.

Self-organisation of small-world networks by adaptive rewiring in response to graph diffusion

Complex networks emerging in natural and human-made systems tend to assume small-world structure. Is there a common mechanism underlying their self-organisation? Our computational simulations show that network diffusion (traffic flow or information transfer) steers network evolution towards emergence of complex network structures. The emergence is effectuated through adaptive rewiring: progressive adaptation of structure to use, creating short-cuts where network diffusion is intensive while annihilating underused connections. With adaptive rewiring as the engine of universal small-worldness, overall diffusion rate tunes the systems’ adaptation, biasing local or global connectivity patterns. Whereas the former leads to modularity, the latter provides a preferential attachment regime. As the latter sets in, the resulting small-world structures undergo a critical shift from modular (decentralised) to centralised ones. At the transition point, network structure is hierarchical, balancing modularity and centrality - a characteristic feature found in, for instance, the human brain.

Parallel and Distributed Methods for Constrained Nonconvex Optimization—Part I: Theory

In Part I of this paper, we proposed and analyzed a novel algorithmic framework for the minimization of a nonconvex (smooth) objective function, subject to nonconvex constraints, based on inner convex approximations. This Part II is devoted to the application of the framework to some resource allocation problems in communication networks. In particular, we consider two non-trivial case-study applications, namely: (generalizations of) i) the rate profile maximization in MIMO interference broadcast networks; and the ii) the max-min fair multicast multigroup beamforming problem in a multi-cell environment. We develop a new class of algorithms enjoying the following distinctive features: i) they are \emph{distributed} across the base stations (with limited signaling) and lead to subproblems whose solutions are computable in closed form; and ii) differently from current relaxation-based schemes (e.g., semidefinite relaxation), they are proved to always converge to d-stationary solutions of the aforementioned class of nonconvex problems. Numerical results show that the proposed (distributed) schemes achieve larger worst-case rates (resp. signal-to-noise interference ratios) than state-of-the-art centralized ones while having comparable computational complexity.

Energy Consumption of Content Distribution from Nano Data Centers versus Centralized Data Centers

Energy consumption of nano data centers has recently been a topic of interest as they emerge as a novel computing and storage platform. We present end-to-end energy consumption models for nano data centers and its centralized counterpart. To assess the energy consumption of nano and centralized data centers, we propose flowbased and time-based energy consumption models for shared and single user network equipment. To evaluate our models, a set of measurements and practical experiments are performed. Our results indicate that nano data centers might lead to energy savings depending on various factors such as location of nano servers, type of access network attached to nano servers, and the ratio of active time to idle time of nano servers. Thus, nano data centers can complement centralized ones and lead to savings energy if certain applications are off-loadable from centralized data centers.

Banking Crises and Institutional Arrangements

What is the role of interbank markets and central banks in coping with banking crises? In experiments using an agent-based framework with multiple banks and an interbank market. I found that when banks cannot interact, then runs in isolated banks occur with a higher frequency than when banks have equal market shares. That is, there are no runs escalating to systemic panics. In contrast, if one bank has a market share twice as big as the rest, runs spread. The presence of a central bank may unexpectedly increase the occurrence of bank runs. Institutional complexity helps to reduce the frequency of bank runs. Hence, decentralized institutional structures perform better than centralized ones.

The Use of Internet Communication by Catholic Congregations: A Quantitative Study

This article presents a first attempt to measure the use of the internet by all 5,812 Catholic religious congregations and autonomous institutes worldwide (with 858,988 members). The research was conducted through a questionnaire sent by e-mail, hence first selecting those institutions which at least have an access to internet communication through an e-mail account (2,285: 39.3% of the total), receiving 437 responses (19.1% of the e-mail owners). The study shows great differences between centralized institutes and autonomous ones: the former ones make a higher use of the Internet than the latter ones; moreover, differences are also found among centralized institutes, namely between male and female ones. Two explanatory elements have been found, both depending on the own mission (charisma) of institutes: (1) first, the different approach to the external world: the institutes more devoted to contemplation and less active in the outside world make limited and basic use of the Internet, if any; (2) second, institutes whose aim is to assist poor and sick persons tend to use the internet less than the others, due to their different prioritization of resources.

Centralization and Political Accountability

In this paper we abstract from the usual gains and costs of decentralization (e.g. preference matching, spillovers and economies of scale). Instead we compare the political accountability of decentralized governments relative to centralized ones when there is a risk of bad governance. We study both the selection and incentive effects of accountability. A key aspect of centralization is to make the politician answerable to multiple constituencies subject to a common budget constraint. Our main findings are that (a) when politicians differ in competence, decentralization unambiguously dominates; and (b) when politicians differ in honesty, decentralization and centralization have conflicting accountability effects (when one provides better discipline, the other gives better selection). The analysis then identifies the circumstances under which centralization may increase voter welfare. The more general lesson that we can draw is that different institutional forms give rise to different information to the voters on which electoral accountability can be based. Therefore they differ on how effective elections can be in disciplining and selecting policymakers.

The viability of decentralized water and sanitation provision in developing countries: the case of Honduras

The sustainable delivery of basic services continues to be an elusive goal for water and sanitation operators in developing countries. In Honduras, both centralized and decentralized providers of water and sanitation coexist simultaneously, providing an opportunity to compare the effectiveness of each approach amid similar constraints. This analysis uses ten variables that measure access, efficiency and sustainability, in comparing the experiences of 16 potable water systems in small- and medium-sized cities, operated by centralized and decentralized water authorities. While neither approach provides a single, integrated model of a best practice, overall the decentralized systems demonstrate better practices than their centralized counterparts. Decentralized potable water systems systematically outperform centralized ones in financial efficiency and in their ability to increase coverage of basic services over time. In large part, the decentralized systems' better practices have been motivated by institutional arrangements that promote political accountability to customers and provide incentives for sustainable management practices. Decentralized operators continue to face challenges, namely the need to apply economic principles in designing tariff regimes and implementing management practices to account for capital depreciation. Despite these challenges, however, this analysis demonstrates that decentralized systems are not only viable in developing countries, but also tend to provide better service than those systems operated by a centralized authority.

A scalable P2P recommender system based on distributed collaborative filtering

Collaborative Filtering (CF) technique has been proved to be one of the most successful techniques in recommender systems in recent years. However, most existing CF based recommender systems worked in a centralized way and suffered from its shortage in scalability as their calculation complexity increased quickly both in time and space when the record in user database increases. In this article, we first propose a distributed CF algorithm called PipeCF together with two novel approaches: significance refinement and unanimous amplification, to further improve the scalability and prediction accuracy. We then show how to implement this algorithm on a Peer-to-Peer (P2P) structure through distributed hash table method, which is the most popular and efficient P2P routing algorithm, to construct a scalable distributed recommender system. The experimental data show that the distributed CF-based recommender system has much better scalability than traditional centralized ones with comparable prediction efficiency and accuracy. q 2004 Elsevier Ltd. All rights reserved.

Addressing Social and Economic Responsibilities through Governance

Loosening the Gordian Knot of Governance in Integrated Health Care Delivery Systems provides a very complete analysis of the issues and components of integrated system governance. Pointer, Alexander, and Zuckerman leave the reader with a framework on which the governance of an integrated health care delivery system (IHCDS) can be conceptualized. For those of us who are entering the new world of system integration, this article provides a checklist of items to consider as we formulate new governance structures. For those of us who are already within an integrated system, the article gives us better definition and understanding of the problems we face in governing a larger entity with diverse constituencies. After paying tribute to this helpful system of taxonomy, we are left thoughtfully nodding in appreciation and agreement but without the answer to the most difficult questions facing many community hospitals contemplating merging into an integrated system. Can a governance structure created to address economic issues accommodate social mission? Community hospitals were created and governed by local citizens to provide health care to towns and cities all across this country. people they served were never described as but as the citizens of neighborhoods and parishes. elements of community transcend the bounds of a term like population and speak to a human consideration with roots based on the very reason that our local hospitals were founded and by which they enjoy philanthropic support. Despite the authors' assertion that IHCDSs must be held responsible for improving the health status of the population, health care institutions and physicians most often seek to merge or integrate, as Russell Coile (1994b) has said, to share a capitated premium in the new world of managed care. This shift in mission from one of service to one of economic survival is the prime angst of those who must justify new governance structures that often relegate important social responsibilities to decentralized advisory boards. authors have drawn on their participation in focus group discussions held among CEOs of integrated systems. Perhaps, as we listen to the voices of individuals already swept into the maelstrom of multi-institutional systems, we should realize that these leaders are irrevocably committed to trying to bolster the governance structure of systems whose most important mission is the survival of the system as an economic force. In reviewing some of the same material generated from the AHA conferences on the governance of integrated systems, I was struck by the rhetoric used to justify such things as the reimbursement of board members or the centralization of decision making. References to the practices of multicompany corporations with centralized authority and focused corporate mission were made with the clear implication the industry provides the governance model that we should emulate in structuring a large IHCDS. Admittedly, it is certainly easier to make crisp business decisions if you can reduce the influence of local community boards whose interests reflect long-standing social missions. Thus, it is the agenda behind the IHCDS rather than the governance structure itself that may be the most important determinant of the appropriate governance model. Integrated system governance, as the authors have outlined, can range from very decentralized systems with a fair amount of local autonomy and representation to highly centralized ones with almost no influence in governance. But is there a governance structure that can accommodate local social concern as well as economic survival? New Concept of Virtual Integration Jeff Goldsmith's (19941 recent article, The Illusive Logic of Integration, reviews the past decade of integrated system formation and finds, like others, that as yet it is hard to document that there is added value to the communities or defined populations they serve. …

Fully decentralized solutions of supervisory control problems

The paper gives a new characterization of solutions of the decentralized supervisory control problem and presents a special class of "fully decentralized" solutions, so called because the main idea is to avoid communication not only among subsupervisors during run-time but also among agents designing the subsupervisors. The solutions are constructed from optimal centralized ones using a worst-case philosophy. Their basic properties and comparison with the partially observable supervisory control problem are given. If it is known a priori that the fully decentralized solution exists, then the supervisor can be computed partly online. A sufficiency test of the existence of such a solution is provided.

Location Patterns of Manufacturing: Toronto in the Early 1880s

The literature on cities simplifies both industrial structure and location patterns of manufacturing in nineteenth-century urban areas, and it conceives of change narrowly in terms of innovations in transportation technology at or after the turn of the century. There are many reasons for rejecting this orthodoxy. Empirical research on Toronto, and other cities, recognizes industries of different scale, capital intensity, labour characteristics, and input-output linkages in the early 1880s. Location patterns for different industries varied from highly centralized ones to those characterized by a great dispersion of factories. There was, however, no straightforward relationship between scale and capital intensity on one hand and location on the other.