scholarly journals Dynamic Windows Scheduling with Reallocation

2021 ◽  
Vol 26 ◽  
pp. 1-19
Author(s):  
Martín Farach-Colton ◽  
Katia Leal ◽  
Miguel A. Mosteiro ◽  
Christopher Thraves Caro
Keyword(s):  
Supply Chain ◽  
Bin Packing ◽  
Time Slot ◽  
Peak Load ◽  
Communication Channels ◽  
Current Load ◽  
Constant Amount ◽  
Unit Fractions ◽  
Consecutive Time ◽  
Multiple Variants

We consider the Windows Scheduling (WS) problem, which is a restricted version of Unit-Fractions Bin Packing, and it is also called Inventory Replenishment in the context of Supply Chain. In brief, WS problem is to schedule the use of communication channels to clients. Each client c i is characterized by an active cycle and a window w i . During the period of time that any given client c i is active, there must be at least one transmission from c i scheduled in any w i consecutive time slots, but at most one transmission can be carried out in each channel per time slot. The goal is to minimize the number of channels used. We extend previous online models, where decisions are permanent, assuming that clients may be reallocated at some cost. We assume that such cost is a constant amount paid per reallocation. That is, we aim to minimize also the number of reallocations. We present three online reallocation algorithms for Windows Scheduling. We evaluate experimentally multiple variants of these protocols showing that, in practice, all three achieve constant amortized reallocations with close to optimal channel usage. Our simulations also expose interesting tradeoffs between reallocations and channel usage. We introduce a new objective function for WS with reallocations that can be also applied to models where reallocations are not possible. We analyze this metric for one of the algorithms that, to the best of our knowledge, is the first online WS protocol with theoretical guarantees that applies to scenarios where clients may leave and the analysis is against current load rather than peak load. Using previous results, we also observe bounds on channel usage for one of the algorithms.

Next-fit bin packing with random piece sizes

1989 ◽  
Vol 26 (3) ◽  
pp. 503-511 ◽  
Author(s):  
Shlomo Halfin
Keyword(s):  
Communication Channel ◽  
Bin Packing ◽  
Communication Channels ◽  
Explicit Solutions ◽  
Size Distributions ◽  
Stochastic Behavior ◽  
Data Packets ◽  
Truncated Distributions ◽  
Piece Size ◽  
Packing Algorithm

Investigations into time-slotted communication channels for transmission of data packets led us to analyze the stochastic behavior of the next-fit bin packing algorithm. In this paper we obtain results for general piece-size distributions and truncated distributions, we calculate explicit solutions for the case of the truncated exponential, and we apply the results to calculate the maximal throughput of the time-slotted communication channel.

scholarly journals Integrated Coordination of Electric Vehicle Operations and Renewable Energy Generation in a Microgrid

2017 ◽  
Vol 7 (2) ◽  
pp. 706
Author(s):  
Junghoon Lee ◽  
Gyung-Leen Park
Keyword(s):  
Renewable Energy ◽  
Electric Vehicles ◽  
Time Slot ◽  
Peak Load ◽  
Energy Generation ◽  
Level Energy ◽  
Parameter Setting ◽  
Energy Potential ◽  
Current Time ◽  
Renewable Energy Generation

This paper designs a microgrid energy controller capable of creating a charging or discharging schedule for electric vehicles (EVs), aiming at leveraging the integration of renewable energy and shaving the peak load in the microgrid. Dynamically activated on each time slot to cope with the prediction error for the power consumption and the renewable energy generation, the controller calculates the number of EVs to charge or make discharge first. Then, a greedy algorithm-based scheduler selects EVs according to the expected energy potential during their stays. The potential is the integral of a supply-demand margin function from the current time to the expected departure time. A simulator is implemented for performance evaluation, comparing with uncoordinated scheduling, according to the number of EVs as well as the behavior of energy load and production. The experiment result shows that the proposed scheme can reduce the energy waste by 16.9 %, cut down the microgrid-level energy insufficiency by 12.2 %, and enhance the amount of electricity supplied to EVs by 37.3 %, respectively, for given parameter setting.

scholarly journals Fuzzy Logic Weight Based Charging Scheme for Optimal Distribution of Charging Power among Electric Vehicles in a Parking Lot

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3119 ◽  
Author(s):  
Shahid Hussain ◽  
Mohamed A. Ahmed ◽  
Ki-Beom Lee ◽  
Young-Chon Kim
Keyword(s):  
Fuzzy Logic ◽  
Electric Vehicles ◽  
Fuzzy Inference ◽  
Time Slot ◽  
Power Grid ◽  
Peak Load ◽  
Parking Lot ◽  
Operational Constraints ◽  
Weighted Values

Electric vehicles (EVs) parking lots are representing significant charging loads for relatively a long period of time. Therefore, the aggregated charging load of EVs may coincide with the peak demand of the distribution power system and can greatly stress the power grid. The stress on the power grid can be characterized by the additional electricity demand and the introduction of a new peak load that may overwhelm both the substations and transmission systems. In order to avoid the stress on the power grid, the parking lot operators are required to limit the penetration level of EVs and optimally distribute the available power among them. This affects the EV owner’s quality of experience (QoE) and thereby reducing the quality of performance (QoP) for the parking lot operators. The QoE is represents the satisfaction level of EV owners; whereas, the QoP is a measurement representing the ratio of EVs with QoE to the total number of EVs. This study proposes a fuzzy logic weight-based charging scheme (FLWCS) to optimally distribute the charging power among the most appropriate EVs in such a way that maximizes the QoP for the parking lot operators under the operational constraints of the power grid. The developed fuzzy inference mechanism resolves the uncertainties and correlates the independent inputs such as state-of-charge, the remaining parking duration and the available power into weighted values for the EVs in each time slot. Once the weight values for all EVs are known, their charging operations are controlled such that the operational constraints of the power grid are respected in each time slot. The proposed FLWCS is applied to a parking lot with different capacities. The simulation results reveal an improved QoP comparing to the conventional first-come-first-served (FCFS) based scheme.

scholarly journals Dynamic Bin Packing of Unit Fractions Items

2005 ◽  
pp. 614-626 ◽  
Author(s):  
Wun-Tat Chan ◽  
Tak-Wah Lam ◽  
Prudence W. H. Wong
Keyword(s):  
Bin Packing ◽  
Unit Fractions

Modeling and Optimization of Inserting Order Schedule of Agile Supply Chain

2011 ◽  
Vol 230-232 ◽  
pp. 910-915
Author(s):  
Xian Feng Huang ◽  
Bo Wu ◽  
Jian Hua Wang
Keyword(s):  
Supply Chain ◽  
Simulated Annealing ◽  
Simulated Annealing Algorithm ◽  
Time Slot ◽  
Scheduling Problem ◽  
Order Scheduling ◽  
Two Stage ◽  
Agile Supply Chain ◽  
Annealing Algorithm ◽  
Production Plans

In order to solve the inserting order scheduling problem of agile supply chains which already have fixed production plans, a two stage supply chain which consists of one factory and many suppliers is studied. Take minimizing the total supply chain cost as the objective, an Integer Planning (IP) model is designed to describe the scheduling problem based on the time slot representation of corps’s available schedule periods, and a Neighbor Value Partial Interchange Simulated Annealing algorithm(NVPI-SA) is proposed to optimize the IP model. Finally, the practicality and effectiveness of the model and algorithm is verified by scheduling experiments.

Next-fit bin packing with random piece sizes

1989 ◽  
Vol 26 (03) ◽  
pp. 503-511
Author(s):  
Shlomo Halfin
Keyword(s):  
Communication Channel ◽  
Bin Packing ◽  
Communication Channels ◽  
Explicit Solutions ◽  
Size Distributions ◽  
Stochastic Behavior ◽  
Data Packets ◽  
Truncated Distributions ◽  
Piece Size ◽  
Packing Algorithm

Investigations into time-slotted communication channels for transmission of data packets led us to analyze the stochastic behavior of the next-fit bin packing algorithm. In this paper we obtain results for general piece-size distributions and truncated distributions, we calculate explicit solutions for the case of the truncated exponential, and we apply the results to calculate the maximal throughput of the time-slotted communication channel.

scholarly journals Methodological principles of forming multichannel digital communication in the supply chains

2020 ◽  
Vol 157 ◽  
pp. 05010
Author(s):  
Vladimir Naumov ◽  
Elena Naumova ◽  
Evgeniy Shteyngart ◽  
Natalya Ostrovskaya
Keyword(s):  
Supply Chain ◽  
Data Exchange ◽  
Digital Communication ◽  
Communication Channels ◽  
Synthesis Process ◽  
Scientific Methods ◽  
Analysis And Synthesis ◽  
Information And Communication ◽  
Entropy Factor ◽  
Methodological Principles

Logistics is undergoing a digital transformation to manage material and intangible flows using various digital communication channels. In this regard, it is extremely urgent to develop a backbone and local IT platforms that unite participants in the supply chain to collect and analyze information for making optimal management decisions. The purpose of this study is to substantiate the main methodological principles of the formation of digital communications between participants in the supply chain to create an inter-corporate information and communication system. In preparing the material, such scientific methods as analysis and synthesis, process modeling, process method, and system approach were used. A model for organizing digital communication in the supply chain using the backbone communication IT platform is proposed. The role of digital trust in the organization of inter-corporate digital communication is shown, and the entropy factor is also taken into account when assessing the throughput of communication channels. The result of the study is the formulation and justification of methodological principles for the introduction of multi-channel digital communication, providing not only electronic data exchange between logistics partners, but also reducing the logistic and transaction costs of supply chain participants.

scholarly journals Energy Storage on a Distribution Network for Self-Consumption of Wind Energy and Market Value

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2688
Author(s):  
Oluwasola O. Ademulegun ◽  
Patrick Keatley ◽  
Motasem Bani Mustafa ◽  
Neil J. Hewitt
Keyword(s):  
Supply Chain ◽  
Wind Energy ◽  
Distribution Network ◽  
Peak Load ◽  
Storage Device ◽  
Electricity Supply ◽  
Electricity Distribution ◽  
Benefit Analysis ◽  
Base Load ◽  
Electricity Supply Chain

Wind energy could be generated and captured with a storage device within the customer premises for local utilization and for the provision of various services across the electricity supply chain. To assess the benefits of adding a storage device to an electricity distribution network that has two wind turbines with a base load of 500 kW and a typical peak load under 1500 kW, a 2 MW/4 MWh storage is installed. To observe the effects of adding the storage device to the network, a technical analysis is performed using the NEPLAN 360 modelling tool while an economic analysis is carried out by estimating the likely payback period on investment. A storage potential benefit analysis suggests how changes in integration policies could affect the utility of adding the storage device. With the addition of the storage device, self-consumption of wind energy increased by almost 10%. The profitability of the project increased when the device is also deployed to provide stacked services across the electricity supply chain. Policies that permit the integration of devices into the grid could increase the profitability of storage projects.

scholarly journals Dynamic bin packing of unit fractions items

2008 ◽  
Vol 409 (3) ◽  
pp. 521-529 ◽  
Author(s):  
Joseph Wun-Tat Chan ◽  
Tak-Wah Lam ◽  
Prudence W.H. Wong
Keyword(s):  
Bin Packing ◽  
Unit Fractions
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