Power Utility Maximization in an Exponential Levy Model Without a Risk-free Asset

We consider the problem of maximizing the expected power utility fromterminal wealth in a market where logarithmic securities prices follow a Lévy process. By Girsanovstheorem, we give explicit solutions for power utility of undiscounted terminal wealth in terms ofthe Lévy-Khintchine triplet.

A Server Placement Algorithm for Reducing Risk and Improving Power Utilization in Data Centers

As the power demand in data centers is increasing,the power capacity of the power supply system has become an essential resource to be optimized.Although many data centers use power oversubscription to make full use of the power capacity,there are unavoidable power supply risks associated with it.Therefore,how to improve the data center power capacity utilization while ensuring power supply security has become an important issue.To solve this problem,we first define it and propose a risk evaluation metric called Weighted Power Supply Risk(WPSRisk).Then,a method,named Hybrid Genetic Algorithm with Ant Colony System(HGAACS),is proposed to improve power capacity utilization and reduce power supply risks by optimizing the server placement in the power supply system.HGAACS uses historical power data of each server to find a better placement solution by population iteration.HGAACS possesses not only the remarkable local search ability of Ant Colony System(ACS),but also enhances the global search capability by incorporating genetic operators from Genetic Algorithm(GA).To verify the performance of HGAACS,we experimentally compare it with five other placement algorithms.The experimental results show that HGAACS can perform better than other algorithms in both improving power utilization and reducing the riskof powersupply system.

Tie-line Power Flow Control Method for Gridconnected Microgrids with SMES Based on Optimization and Fuzzy Logic

In an active distribution grid,renewable energy sources(RESs)such as photovoltaic(PV)and energy storage systems(e.g.,superconducting magnetic energy storage(SMES))can be combined with consumers to compose a microgrid(MG).The high penetration of PV causes high fluctuations of tie-line power flow and highly affects power system operations.This can lead to several technical problems such as voltage fluctuations and excessive power losses.In this paper,a fuzzy logic control based SMES method(FSM)and an optimized fuzzy logic control based SMES method(OFSM)are proposed for minimizing the tie-line power flow.Consequently,the fluctuations and transmission power losses are decreased.In FSM,SMES is used with a robust fuzzy logic controller(FLC)for controlling the tie-line power flow.An optimization model is employed in OFSM to simultaneously optimize the input parameters of the FLC and the reactive power of the voltage source converter(VSC)of SMES.The objective function of minimizing the tieline power flow is incorporated into the optimization model.Particle swarm optimization(PSO)algorithm is utilized to solve the optimization problem while the constraints of the utility power grid,VSC,and SMES are considered.The simulation results demonstrate the effectiveness and robustness of the proposed methods.

Homotopy Analysis Method for Portfolio Optimization Problem Under the 3/2 Model

This paper considers the Merton portfolio optimization problem for an investor that aims at maximizing the expected power utility of the terminal wealth and intermediate consumption.Applying the homotopy analysis method,an analytical solution for value function as well as optimal strategy under the 3/2 model is derived,respectively.Compared with the existing explicit solutions for Merton problem under the 3/2 model,the formulas provide certain parameters with less requirement since the homotopy analysis method does not depend on the existence of small parameters in the equation.Finally,numerical examples are examined with the approach,and the proposed solution provides more accurate approximation as the number of terms in infinite series increases.

Theoretical analysis and experimental verification of a cost-effective chromatic dispersion monitoring method in a 40-Gb/s optical fiber communication system

A cost-effective technique for in-service chromatic dispersion monitoring in a 40-Gb/s optical communication system is proposed. Microwave devices are adopted to detect the electrical power of a specific frequency band. A simplified theoretical model is proposed and discussed focusing on the relationship between electrical power and chromatic dispersion at different frequency bands. The dynamic monitoring of chromatic dispersion is achieved using devices such as PIN detector, microwave amplifier, narrow-band microwave filter, and electrical power detector. The maximum detectable chromatic dispersion is 130 ps/nm and a resolution of 5.2 ps/nm/dB has been achieved in the frequency band centered at 12 GHz.