Abstract-Transmission Control Protocol (TCP) is the most popular transport layer protocol for the Internet. Due to various reasons, such as multipath routing, route fluttering, and retransmissions, packets belonging to the same flow may arrive out of order at a destination. Such packet reordering violates the design principles of some traffic control mechanisms in TCP and, thus, poses performance problems. In this paper, we provide a comprehensive and in-depth survey on recent research on packet reordering in TCP. The causes and problems for packet reordering are discussed. Various representative algorithms are examined and compared by computer simulations. The ported program codes and simulation scripts are available for download. Some open questions are discussed to stimulate further research in this area.
Due to various green initiatives, renewable energy will be massively incorporated into the future smart grid. However, the intermittency of the renewables may result in power imbalance, thus adversely affecting the stability of a power system. Frequency regulation may be used to maintain the power balance at all times. As electric vehicles (EVs) become popular, they may be connected to the grid to form a vehicle-to-grid (V2G) system. An aggregation of EVs can be coordinated to provide frequency regulation services. However, V2G is a dynamic system where the participating EVs come and go independently. Thus, it is not easy to estimate the regulation capacities for V2G. In a preliminary study, we modeled an aggregation of EVs with a queueing network, whose structure allows us to estimate the capacities for regulation-up and regulation-down separately. The estimated capacities from the V2G system can be used for establishing a regulation contract between an aggregator and the grid operator, and facilitating a new business model for V2G. In this paper, we extend our previous development by designing a smart charging mechanism that can adapt to given characteristics of the EVs and make the performance of the actual system follow the analytical model. Index Terms-Capacity, frequency regulation, queueing model, vehicle-to-grid (V2G).
Aberrant signaling of the FGF/FGFR pathway occurs frequently in cancers and is an oncogenic driver in many solid tumors. Clinical validation of FGFR as a therapeutic target has been demonstrated in bladder, liver, lung, breast, and gastric cancers. Our goal was to develop an irreversible covalent inhibitor of FGFR1-4 for use in oncology indications. An irreversible covalent binding mechanism imparts many desirable pharmacological benefits including high potency, selectivity, and prolonged target inhibition. Herein we report the structure-based design, medicinal chemistry optimization, and unique ADME assays of our irreversible covalent drug discovery program which culminated in the discovery of compound 34 (PRN1371), a highly selective and potent FGFR1-4 inhibitor.
Social cynicism, a negative view about people and social institutions, was found to show a negative correlation with job satisfaction across societies. A preliminary study in Hong Kong showed that social cynicism and job satisfaction correlated negatively across individuals as well. To confirm the causal effect of social cynicism on job satisfaction, a longitudinal study in Shanghai, China, with three waves of surveys, was conducted. Results showed that social cynicism correlated negatively with job satisfaction measured concurrently, and was predictive of job satisfaction measured subsequently. Consistent with the buffering hypothesis, perceived well-being was a significant moderator in that the negative relationship between social cynicism and job satisfaction was significant only when perceived well-being was low.a pps_392 318..338 On s'est aperçu que le cynisme social (une vision négative des gens et des institutions sociales) entretenait une corrélation négative avec la satisfaction professionnelle quelle que soit la société. Une étude préliminaire à Hong-Kong a montré que le cynisme social et la satisfaction professionnelle présentaient également une corrélation négative au niveau de l'individu. Dans le but de confirmer le statut causal du cynisme social sur la satisfaction professionnelle, on a mené une étude longitudinale en Chine, à Shanghai, avec trois enquêtes successives. Les résultats montrent que le cynisme social est négativement relié à la satisfaction professionnelle mesurée au même moment et prédit la satisfaction professionnelle mesurée ultérieurement. En accord avec l'hypothèse portant sur la résistance aux aléas de l'existence, le bien-être perçu est un modérateur actif dans la mesure où la relation négative entre le cynisme social et la satisfaction professionnelle n'est significative que lorsque le bien-être perçu est médiocre.
In a vehicle-to-grid (V2G) system, aggregators coordinate the charging/discharging schedules of electric vehicle (EV) batteries so that they can collectively form a massive energy storage system to provide ancillary services, such as frequency regulation, to the power grid. In this paper, the optimal charging/discharging scheduling between one aggregator and its coordinated EVs for the provision of the regulation service is studied. We propose a scheduling method that assures adequate charging of EVs and the quality of the regulation service at the same time. First, the scheduling problem is formulated as a convex optimization problem relying on accurate forecasts of the regulation demand. By exploiting the zero-energy nature of the regulation service, the forecast-based scheduling in turn degenerates to an online scheduling problem to cope with the high uncertainty in the forecasts. Decentralized algorithms based on the gradient projection method are designed to solve the optimization problems, enabling each EV to solve its local problem and to obtain its own schedule. Our simulation study of 1,000 EVs shows that the proposed online scheduling can perform nearly as well as the forecast-based scheduling, and it is able to smooth out the real-time power fluctuations of the grid, demonstrating the potential of V2G in providing the regulation service.
Power flow routing is an emerging control paradigm for the dynamic control of electric power flows. In this paper, we propose a generic model of a power flow router (PFR) and incorporate it into the optimal power flow (OPF) problem. First, a generic PFR architecture is proposed to encapsulate the desired functions of PFRs. Then, the load flow model of PFRs is developed and incorporated into the OPF framework. To pursue global optimality of the non-convex PFR-incorporated OPF (PFR-OPF) problem, we develop a semidefinite programming (SDP) relaxation of PFR-OPF. By introducing the regularization terms that favor a low-rank solution and tuning the penalty coefficients, a rank-1 solution can be obtained and used for recovering an optimal or near-optimal solution of the PFR-OPF and the results are verified in numerical tests. The efficacy of the PFR-OPF framework allows us to investigate the impact of PFR integration. With the system loadability as an example, the numerical results show that remarkable enhancement can be achieved by installing PFRs at certain critical buses of the network.
he Internet provides a convenient and cost-effective communication platform for electronic commerce, education, and entertainment. The success of the Internet stems from its capabilities to support survivable, robust, and reliable end-to-end data transfer services for a myriad of applications running over a set of end-systems. The Internet originated from the Advanced Research Projects Agency Network (ARPANET) designed to support survivable military communications. Currently, the Transmission Control Protocol (TCP) [1] is the most popular transport layer protocol for point-to-point, connection-oriented, in-order, reliable data transfer in the Internet. TCP is the de facto standard for Internet-based commercial communication networks.
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