Framework For Interconnection Research Articles

COSMO-RS and LSER models of solution thermodynamics: Towards a COSMO-LSER equation of state model of fluids

The present work examines the formulation of a statistical thermodynamic framework for the direct interconnection of the quantum-mechanics based COSMO-RS (Conductor Screening Model for Realistic Solvation) model with Abraham’s LSER (Linear Solvation Energy Relationship) model and LSER molecular descriptors. The focus is on the hydrogen-bonding (HB) contribution to solvation enthalpy. An extensive comparison is made between COSMO-RS predictions of the HB contribution to solvation enthalpy of a variety of solute – solvent systems and the corresponding LSER predictions. A rather good agreement is observed in most of the studied systems. The cases of large discrepancies are also compared with corresponding equation-of-state calculations. The perspectives for a combination of COSMO-RS, LSER and equation-of-state approaches, which would lead to the development of a COSMO-LSER equation-of-state framework are critically discussed.

Security assessment of transnational power interconnection between China and neighboring countries

China and its neighboring countries are energy-dependent regions with strong resource complementarity and significant benefits of cross-border grid interconnection. However, the power interconnection of the whole Greater China region is still far from being realized. In addition to internal factors, external geopolitical issues, grid interconnection technical issues, and geographical obstacles also pose certain security challenges to the creation of regional power grids. To quantify the security of power grid interconnection between China and neighboring countries, this study proposes a security assessment framework for the power interconnection between China and neighboring countries from the five dimensions of politics, economy, law, technology, and geographic environment. We collected the observable panel data of China's neighboring countries from 2011 to 2018 and used the entropy method to objectively evaluate the security of power interconnection between China and 22 countries in the four regions of Northeast Asia, Central Asia, South Asia, and Southeast Asia. The study proposes the feasible paths for power interconnection between China and surrounding countries based on the investigation on the interconnection advantages and security shortcomings of each region and country by combining the endowment of renewable energy resources in each region.

New framework for parallel interconnection of buck converters: Application to optimal current-sharing with constraints and unknown load

In this paper, heterogeneous set of parallel buck converters, feeding an unknown resistive load via a common DC bus, is considered. When addressing control design problem of this interconnected power converter, one has to accommodate competing objectives of (i) voltage regulation and (ii) power distribution among branches, also called current-sharing in this context. Related dynamics being coupled, classical solution resorts to frequency separation to prevent undesirable interaction between them. In stark contrast with this approach, this paper proposes a novel framework which completely separate voltage regulation from current distribution dynamics without frequency separation, hence offering tractability without sacrificing performance. Such a reformulation is performed on the open-loop model so that control law candidates are not confined in some particular class. Arbitrary large set of heterogeneous converters can be handled. Remarkably, voltage regulation boils down to the control of a single virtual buck converter. Controller design example exploiting the new structure is provided. In the context of unknown resistive load, this controller achieves voltage regulation and minimizes overall power losses at the steady-state while taking current limits of each branch into account. Those results are supported by formal statements and proofs, and assessed through experimental results.

Uma proposta de estrutura e utilização do gerenciamento de processos de negócio (BPM)

Os Processos organizacionais, também chamados de processos de negócio, tornaram-se estruturas fundamentais para o gerenciamento das organizações modernas. Segundo alguns autores, conhecer o fluxo de trabalho das organizações é uma condição necessária para o desenvolvimento de processos de melhoria contínua. São evidentes os benefícios e vantagens proporcionados pela utilização de uma abordagem fundamentada no gerenciamento de processos BPM (Business Process Management). Dentre os benefícios, são apontados ganhos de eficiência, qualidade e flexibilidade, além de outros aspectos para que se criem vantagens competitivas sustentáveis. Há na literatura de BPM estudos abrangentes sobre o tema, no qual pode-se observar diversas definições e elementos que caracterizam as diferentes aplicações. O objetivo deste artigo é propor um framework conceitual de interligação entre os elementos BPM, buscando um melhor entendimento sobre os processos organizacionais e atuação no ambiente da gestão organizacional. São realizados estudos exploratórios de identificação e classificação de elementos BPM. Para analisar as interligações entre eles realizou-se uma revisão da literatura e desenvolveu-se um estudo sobre a utilização profissional do BPM. Como resultados é apresentado um conjunto de elementos BPM na forma de: metodologias, técnicas e ferramentas que compõem ou possam ser ligados de forma funcional à estrutura conceitual do BPM. Com esta pesquisa é possível afirmar que os resultados da aplicação do BPM não se limitam à busca do aumento de eficiência operacional, podendo também ser considerado elemento chave de suporte à gestão organizacional.

On the Mathematical Structure of Balanced Chemical Reaction Networks Governed by Mass Action Kinetics

Motivated by recent progress on the interplay between graph theory, dynamics, and systems theory, we revisit the analysis of chemical reaction networks described by mass action kinetics. For reaction networks possessing a thermodynamic equilibrium we derive a compact formulation exhibiting at the same time the structure of the complex graph and the stoichiometry of the network, and which admits a direct thermodynamical interpretation. This formulation allows us to easily characterize the set of positive equilibria and their stability properties. Furthermore, we develop a framework for interconnection of chemical reaction networks, and we discuss how the formulation leads to a new approach for model reduction.

Network-aware scheduling for real-time execution support in data-intensive optical Grids

High performance communication support is a critical aspect for modern Grid environments where the deployment of data-intensive applications often requires moving Petabytes of data between geographically distant data repositories in specific time ranges. The best-effort delivery system of the Internet, often used as the underlying transport network, imposes severe constraints on the transfer of massive amounts of data, and thus restricts the deployment of the above applications on wide-area scales. Besides the lack of bandwidth, the inability to provide dedicated links makes the current network technology not well suited for performance critical Grid computing. A solution is needed to provide dedicated end-to-end connections, dynamically allocable on-demand or by scheduled reservation to critical data-intensive applications. Wavelength routing is at the state of the art the most promising solution to realize such connections. Accordingly, we propose an evolutionary Grid approach built on inter-domain end-to-end lightpath provisioning, controlled by a meta-scheduling logic on advance reservation basis, offering the required connectivity services to the involved Grid nodes by influencing job scheduling decisions with network-related information. We discuss opportunities and challenges in the network control plane and Grid middleware design, together with the required interfaces, adapters and algorithms critical to the provision of network-assisted extensible resource scheduling services. The proposed solution will result in a flexible Grid architecture that supports cooperation between different scheduling entities, based on a scalable framework for dynamic configuration and interconnection of multiple types of resources for high performance Grid applications over globally distributed optical network systems.

TP case study: fixed–mobile interconnection in India

The Telecommunications Regulatory Authority of India (TRAI) attempted, in late 1999, to introduce the calling party pays (CPP) regime for mobile cellular services, with a corresponding revenue-sharing arrangement between fixed and mobile operators. According to the revenue-sharing proposal, mobile operators in India were to be compensated for carrying traffic to and from the fixed networks. Under their original license conditions, fixed operators (usually one of the two state-owned incumbents) were not paying mobile operators for terminating calls on their networks. However, mobile operators had to compensate the state-owned incumbent for terminating traffic. This unfavourable environment for mobile operators has meant that mobile services have not been able to reach their full potential in India. There was great disappointment within the mobile industry when the TRAI's CPP order was overturned by the Supreme Court of India in early 2000, due to lack of jurisdiction. Since then, the enabling legislation has been amended. It is hoped that the new provisions of the TRAI Act will empower the regulator to establish a level playing field for mobile network operators. It is only through the creation of a suitable framework for interconnection that the TRAI will be able to ensure the success of telecommunications reform in India.

Power politics

An overview is presented of the influence of social forces on technological change, based on the experiences involved in the establishment of the Pennsylvania-New Jersey Interconnection (PNJ), the first 220-kV transmission system between independent companies in the US that was established in 1927. None of the precursor efforts-federal, state, or private-were able to develop a politically acceptable administrative framework for high-voltage interconnection. The author discusses the interplay of political, economic, and personal factors evoked by the proposals considered for such an interconnection which reflected the contemporary national debate on the future of electric utilities. It is concluded that the early success of the PNJ was due to the fact that its design did not disrupt existing patterns of ownership and regulation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>