Effective TCP Flow Management Based on Hierarchical Feedback Learning in Complex Data Center Network

Many studies focusing on improving Transmission Control Protocol (TCP) flow control realize a more effective use of bandwidth in data center networks. They are excellent ways to more effectively use the bandwidth between clients and back-end servers. However, these schemes cannot achieve the total optimization of bandwidth use for data center networks as they do not take into account the path design of TCP flows against a hierarchical complex structure of data center networks. To address this issue, this paper proposes a TCP flow management scheme specified a hierarchical complex data center network for effective bandwidth use. The proposed scheme dynamically controls the paths of TCP flows by reinforcement learning based on a hierarchical feedback model, which obtains an optimal TCP flow establishment policy even if both the network topology and link states are more complicated. In evaluation, the proposed scheme achieved more effective bandwidth use and reduced the probability of TCP incast up to 30% than the conventional TCP flow management schemes: Variant Load Balancing (VLB), Equal Cost Multi Path (ECMP), and Intelligent Forwarding Strategy Based on Reinforcement Learning (IFS-RL) in the complex data center network.

FEATURES OF CALCULATION AND ANALYSIS OF FREE CASH FLOW

The features are investigated, systematized, and reserves for improving the process of calculating and analyzing free cash flow are identified. The sources of information have been clarified, and a new indicator for assessing the effectiveness of cash flow management – the economic return on assets on free cash flow - has been recommended

Advancing stream classification and hydrologic modeling of ungaged basins for environmental flow management in coastal southern California

Environmental streamflow management can improve the ecological health of streams by returning modified flows to more natural conditions. The Ecological Limits of Hydrologic Alteration (ELOHA) framework for developing regional environmental flow criteria has been implemented to reverse hydromodification across the heterogenous region of coastal southern California (So. CA) by focusing on two elements of the flow regime: streamflow permanence and flashiness. Within ELOHA, classification groups streams by hydrologic and geomorphic similarity to stratify flow-ecology relationships. Analogous grouping techniques are used by hydrologic modelers to facilitate streamflow prediction in ungaged basins (PUB) through regionalization. Most watersheds, including those needed for stream classification and environmental flow development, are ungaged. Furthermore, So. CA is a highly heterogeneous region spanning a gradient of urbanization, which presents a challenge for regionalizing ungaged basins. In this study, we develop a novel classification technique for PUB modeling that uses an inductive approach to group regional streams by modeled hydrologic similarity followed by deductively determining class membership with hydrologic model errors and watershed metrics. As a new type of classification, this “Hydrologic Model-based Classification” (HMC) prioritizes modeling accuracy, which in turn provides a means to improve model predictions in ungaged basins, while complementing traditional classifications and improving environmental flow management. HMC is developed by calibrating a regional catalog of process-based rainfall-runoff models, quantifying the hydrologic reciprocity of calibrated parameters that would be unknown in ungaged basins, and grouping sites according to hydrologic and physical similarity. HMC was applied to 25 USGS streamflow gages in the south coast region of California and was compared to other hybrid PUB approaches combining inductive and deductive classification. Using an Average Cluster Error metric, results show HMC provided the most hydrologically similar groups according to calibrated parameter reciprocity. Hydrologic Model-based Classification is relatively complex and time-consuming to implement, but it shows potential for advancing ungaged basin management. This study demonstrates the benefits of thorough stream classification using multiple approaches, and suggests that Hydrologic Model-based Classification has advantages for PUB and building the hydrologic foundation for environmental flow management.

Analysis of Construction Implementation Time and Cost Scheduling by Adjusting Budget Changes Due to the Covid-19 Pandemic (Case Study on the Randugunting Dam Construction Project)

The Randugunting Dam, located in Blora Regency, is planned to have a capacity of 10.40 million m and is expected to irrigate an area of 630 Ha, providing a raw water supply of 0.15 m/second. The construction activity of the Randugunting Dam is one of the construction works that has been affected by the Covid-19 pandemic, namely cash flow is hampered. Therefore we need an analysis of cash flow management scenarios and determining strategies for handling the impact of the pandemic on implementation. The data used in this study is the result of interviews with the project implementation team for the Randugunting Dam construction, and data on the project cost budget. Cash flow management analysis is carried out by applying 3 scenarios, namely: scenario 1 (fixed time), scenario 2 (slowed down time), and scenario 3 (accelerated time). The analysis was carried out with the help of the Microsoft Project 2010. The determination of the handling strategy in this study used the DSS (Decision Support System) method, and the SWOT (Strength, Weakness, Opportunity, and Threat). The results of the study chose scenario 3, which is to speed up the time of 6 months. Acceleration is done by increasing the working time. The annual cost required is higher than scenario 1 (fixed time) and 2 (delayed time by 7 months), but the building is completed faster and can be used immediately. The strategy generated by SWOT analysis is Diversity Strategy and produces 8 (eight) strategies. Diversity Strategy is a strategy by maximizing internal strength factors (S), namely increasing the internal capabilities of project implementers and avoiding external threat factors (T), especially related to the Covid-19 pandemic.

Review of the Optimization of PV System to the Grid Network

Among the potential renewable energies, photovoltaic (PV) has experienced enormous growth of generating electricity. In the modern power systems, the effectiveness of grid-tied PV systems has become a spotlight topic for researchers in this field. This paper presents a review on the optimization of PV system to the grid, considering the improvement that will be done to the grid network after connecting the PV system to the grid. A simulation under Matlab/Simulink have been carried out to prove the performance of the proposed power flow management. The objective is to show that the using of grid-connected PV will make a stabilization and increase the reliability to the network. Keywords: Photovoltaic, Grid connected

Optimal Urban Logistics - Through the Choice of Sustainable Axes

In a world where urbanization is becoming more and more widespread, big figures can be seen around internal urban migration further aggravating the environmental urban situation, which results from several previous factors. This is the case with globalization, online shopping, or polluting industrial and human sources. The major solutions are centered primarily on the concern for urban mobility, the involvement of the stakeholders concerned, the optimization of journeys, the use of lanes and roads, the choice of vehicles as well as the zoning or choice of logistics locations. Sustainability is one of the primary elements of flow management; it is one of the most important pillars of the concept of "urban logistics". Indeed, the final goal goes beyond the delivery of goods, going so far as to place the environment as an essential support for urban logistics. In this paper we present a literature review on sustainable logistics, we will try to answer the following problem: Urban logistics: Where are we? To respond to this problem, we are taking the following approach: Presentation of the basic concepts, choice of articles to be used for the study which will induce us to determine the axes and the main actors, with the aim of specifying the most predominant aspects which must be treated and prioritized in order to make urban logistics more optimal.

Optimization of standard arrival procedures at Sheremetyevo airport using rnav path terminators

Holding patterns are established at international airports to make the arriving traffic flow smooth and efficient. One of the main aims of holding patterns is to extend the aircraft arrival route, which allows ATC units to arrange the sequence on the arrival routes more effectively. The article considers the current methods and offers new ideas to improve the efficiency of the inbound traffic flow management using Paths and Terminators concept with HA holding patterns for standard arrival routes at Sheremetyevo Airport. As the main idea for optimizing air traffic management on this stage and reducing the workload on the controller, it is proposed to create extra routes in addition to the existing ones which include holding patterns, that will be used when needed to ensure a well-ordered traffic. The probabilistic method is used to calculate the maximum capacity of existing and proposed arrival routes with holding patterns. The proposed options for restructuring the airspace of the Moscow Terminal Control Area with preserving waypoints of starting standard arrival routes are presented.