Konkuk University

About: Konkuk University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Apoptosis. The organization has 13405 authors who have published 27027 publications receiving 506313 citations.

Electroactive Shape‐Memory Polyurethane Composites Incorporating Carbon Nanotubes

Abstract: Summary: Electro-active shape-memory composites were synthesized using conducting polyurethane (PU) composites and multi-walled carbon nanotubes (MWNTs) Surface modification of the MWNTs (by acid treatment) improved the mechanical properties of the composites The modulus and stress at 100% elongation increased with increasing surface-modified MWNT content, while elongation at break decreased MWNT surface modification also resulted in a decrease in the electrical conductivity of the composites, however, as the surface modified MWNT content increased the conductivity increased (an order of 10−3 S · cm−1 was obtained in samples with 5 wt-% modified-MWNT content) Electro-active shape recovery was observed for the surface-modified MWNT composites with an energy conversion efficiency of 104% Hence, PU-MWNT composites may prove promising candidates for use as smart actuators The electro-active shape-recovery behavior of PU-MWNT composites The pictured transition occurs within 10 s when a constant voltage of 40 V is applied

An Improved Particle Swarm Optimization for Nonconvex Economic Dispatch Problems

Abstract: This paper presents an efficient approach for solving economic dispatch (ED) problems with nonconvex cost functions using an improved particle swarm optimization (IPSO). Although the particle swarm optimization (PSO) approaches have several advantages suitable to heavily constrained nonconvex optimization problems, they still can have the drawbacks such as local optimal trapping due to premature convergence (i.e., exploration problem), insufficient capability to find nearby extreme points (i.e., exploitation problem), and lack of efficient mechanism to treat the constraints (i.e., constraint handling problem). This paper proposes an improved PSO framework employing chaotic sequences combined with the conventional linearly decreasing inertia weights and adopting a crossover operation scheme to increase both exploration and exploitation capability of the PSO. In addition, an effective constraint handling framework is employed for considering equality and inequality constraints. The proposed IPSO is applied to three different nonconvex ED problems with valve-point effects, prohibited operating zones with ramp rate limits as well as transmission network losses, and multi-fuels with valve-point effects. Additionally, it is applied to the large-scale power system of Korea. Also, the results are compared with those of the state-of-the-art methods.