SWIPT-Aware Fog Information Processing: Local Computing vs. Fog Offloading

This paper studies a simultaneous wireless information and power transfer (SWIPT)-aware fog computing by using a simple model, where a sensor harvests energy and receives information from a hybrid access point (HAP) through power splitting (PS) receiver architecture. Two information processing modes, local computing and fog offloading modes are investigated. For such a system, two optimization problems are formulated to minimize the sensor’s required power for the two modes under the information rate and energy harvesting constraints by jointly optimizing the time assignment and the transmit power, as well as the PS ratio. The closed-form and semi-closed-form solutions to the proposed optimization problems are derived based on convex optimization theory. Simulation results show that neither mode is always superior to the other one. It also shows that when the number of logic operations per bit associated with local computing is less than a certain value, the local computing mode is a better choice; otherwise, the fog offloading mode should be selected. In addition, the mode selection associated with the positions of the user for fixed HAP and fog server (FS) is also discussed.

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Closed-form solutions to a class of H∞-optimization problems

International Journal of Control ◽

10.1080/00207179408921451 ◽

1994 ◽

Vol 60 (1) ◽

pp. 41-70 ◽

Cited By ~ 5

Author(s):

ALI SABERI ◽

BEN M. CHEN ◽

ZONGLI LIN

Keyword(s):

Closed Form ◽

Optimization Problems ◽

Closed Form Solutions

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Multi-Objective Optimization of Fog Computing Assisted Wireless Powered Networks: Joint Energy and Time Minimization

Electronics ◽

10.3390/electronics8020137 ◽

2019 ◽

Vol 8 (2) ◽

pp. 137 ◽

Cited By ~ 1

Author(s):

Yuan Liu ◽

Ke Xiong ◽

Yu Zhang ◽

Li Zhou ◽

Fuhong Lin ◽

...

Keyword(s):

Closed Form ◽

Optimization Problems ◽

Fog Computing ◽

Lambert W Function ◽

Closed Form Expression ◽

Optimal Time ◽

Multi Objective Optimization ◽

Transmit Power ◽

Multi Objective ◽

Sensor Device

This paper studies the optimal design of the fog computing assisted wireless powered network, where an access point (AP) transmits information and charges an energy-limited sensor device with Radio Frequency (RF) energy transfer. The sensor device then uses the harvested energy to decode information and execute computing. Two candidate computing modes, i.e., local computing and fog computing modes, are considered. Two multi-objective optimization problems are formulated to minimize the required energy and time for the two modes, where the time assignments and the transmit power are jointly optimized. For the local computing mode, we obtain the closed-form expression of the optimal time assignment for energy harvesting by solving a convex optimization problem, and then analyze the effects of scaling factor between the minimal required energy and time on the optimal time assignment. For the fog computing mode, we derive closed-form and semi-closed-form expressions of the optimal transmit power and time assignment for offloading by adopting the Lagrangian dual method, the Karush–Kuhn–Tucker (KKT) conditions and Lambert W Function. Simulation results show that, when the sensor device has poor computing capacity or when it is far away from the AP, the fog computing mode is the better choice; otherwise, the local computing is preferred to achieve a better performance.

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Closed-form solutions to a class of H/sup infinity /-optimization problems-output feedback case

[1992] Proceedings of the 31st IEEE Conference on Decision and Control ◽

10.1109/cdc.1992.371389 ◽

2005 ◽

Author(s):

A. Saberi ◽

B.M. Chen ◽

Z. Lin

Keyword(s):

Closed Form ◽

Output Feedback ◽

Optimization Problems ◽

Closed Form Solutions

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Outage Performance of Relay-Assisted Single- and Dual-Stage NOMA Over Power Line Communications

10.36227/techrxiv.14787588.v1 ◽

2021 ◽

Author(s):

ROOPESH RAMESH ◽

Sanjeev Gurugopinath ◽

sami muhaidat

Keyword(s):

Closed Form ◽

Communication Systems ◽

Multiple Access ◽

Optimization Problems ◽

Power Line ◽

Closed Form Solutions ◽

Power Line Communications ◽

Optimal Power ◽

Dual Stage ◽

Outage Probabilities

<p>In this paper, we analyze the performance of relay-assisted, single-stage (SS) non-orthogonal multiple access (NOMA) and dual-stage (DS) NOMA power line communication systems. Specifically, derive closed form expressions for the outage probabilities of the SS NOMA and DS NOMA schemes. Subsequently, we formulate optimization problems and obtain closed-form solutions for the optimal power allocation coefficients of the SS NOMA and DS NOMA scheme, such that the probability of overall outage is minimized. The accuracy of our analysis and the tightness of the approximations employed are validated through Monte Carlo simulations and numerical techniques. Moreover, we show that the DS NOMA scheme outperforms the SS NOMA scheme, in terms of the overall outage probability.</p>

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Outage Performance of Relay-Assisted Single- and Dual-Stage NOMA Over Power Line Communications

10.36227/techrxiv.14787588 ◽

2021 ◽

Author(s):

ROOPESH RAMESH ◽

Sanjeev Gurugopinath ◽

sami muhaidat

Keyword(s):

Closed Form ◽

Communication Systems ◽

Multiple Access ◽

Optimization Problems ◽

Power Line ◽

Closed Form Solutions ◽

Power Line Communications ◽

Optimal Power ◽

Dual Stage ◽

Outage Probabilities

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On Global, Closed-Form Solutions to Parametric Optimization Problems for Robots With Energy Regeneration

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4037653 ◽

2017 ◽

Vol 140 (3) ◽

Cited By ~ 4

Author(s):

Poya Khalaf ◽

Hanz Richter

Keyword(s):

Energy Storage ◽

Closed Form ◽

Parametric Optimization ◽

Optimization Problems ◽

Electric Energy ◽

Energy Utilization ◽

Closed Form Solutions ◽

Motion Trajectories ◽

Asymptotic Tracking ◽

Regenerative Energy

Parametric optimization problems are considered for serial robots with regenerative drive mechanisms. A subset of the robot joints are conventional, in the sense that external power is used for actuation. Other joints are energetically self-contained passive systems that use (ultra)capacitors for energy storage. Two different electrical interconnections are considered for the regenerative drives, a distributed and a star configuration. The latter allows for direct electric energy redistribution among joints, a novel idea shown in this paper to enable higher energy utilization efficiencies. Closed-form expressions are found for the optimal manipulator parameters (link masses, link lengths, etc.) and drive mechanism parameters (gear ratios, etc.) that maximize regenerative energy storage between any two times, given motion trajectories. A semi-active virtual control strategy previously proposed is used to achieve asymptotic tracking of trajectories. Optimal solutions are shown to be global and unique. In addition, closed-form expressions are provided for the maximum attainable energy. This theoretical maximum places limits on the amount of energy that can be recovered. The results also shed light on the comparative advantages of the star and distributed configurations. A numerical example with a double inverted pendulum and cart system is provided to demonstrate the results.

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