오재혁 교수

Although a lot of effort has been recently devoted to the capturability analysis of the pure proportional navigation guidance (PPNG) law, there are still significant discrepancies between the analysis results and the actual capturability of the PPNG law. In this paper, a Lyapunov-like approach along with a vector analysis method based on the so-called LOS (line of sight) plane is introduced to analyze the capturability of the 3-dimensional PPNG law against a target maneuvering arbitrarily with t

This paper presents a new approach to acceleration control of STT (Skid-To-Turn) missiles. In the design and stability analysis of our autopilot, we assume perfect roll-stabilization but consider fully all other nonlinearities of the missile dynamics including the coupling effect due to bank angle. Our autopilot controller consists of a partial-linearizing controller and a dynamic compensator. The partial-linearizing controller along with a time scaled transformation can convert the nonlinear mi

Presents a solution to the output regulation problem of a nonlinear system with time-varying disturbance: the system represents the well-known missile-target pursuit situation where the missile is guided by the pure proportional navigation guidance (PPNG) law while the target maneuvers with time-varying normal acceleration, and the problem is to prove the zero miss distance property of PPNG, which has been studied for decades without satisfactory success. To solve this problem, we construct a fu

Considers the problem of resolving conflicts involving multiple aircraft. First a framework is formulated where conflicts may be solved efficiently. Within this framework, the conflict resolution problem is shown to be a non-convex, quadratically constrained quadratic program. Cheap lower bounds to this problem are developed based on positive semidefinite relaxations of the dual of this program. A unique method is proposed to systematically determine the regions of the state-space where the conf

This paper considers a multiple conflict resolution problem for air traffic control systems. The time required to optimally solve aircraft conflicts is known to grow exponentially with the number of aircraft involved and may become prohibitive when large numbers of aircraft are involved. As an attempt to circumvent this issue, a heuristic polynomial-time conflict resolution algorithm is proposed on the basis of analysis results on the relationship between primal and dual quadratic programs.

We have studied holographic Wilsonian renormalization group (HWRG) of free massless fermionic fields in AdS space and its stochastic quantization (SQ) by identifying the Euclidean action with its boundary on-shell action. The natural extension of the relation between stochastic two-point correlation function and double trace coupling obtained from HWRG computation conjectured in [J.-H. Oh and D. P. Jatkar, J. High Energy Phys. 1211, 144 (2012) arXiv:1209.2242] to fermionic fields is established.

Many future air traffic control tasks will require online safety-critical optimization algorithms. Among these tasks, real-time air traffic conflict resolution involving more than two aircraft is one of the most challenging. Air traffic control systems based on online optimization algorithms must face safety-certification issues such as guaranteed feasibility and guaranteed time of computation. This paper deals with the question of guaranteed feasibility and presents an initial effort at develop

A bstract We explore conformally coupled scalar theory in AdS 6 extensively and their classical solutions by employing power expansion order by order in its self-interaction coupling λ. We describe how we get the classical solutions by diagrammatic ways which show general rules constructing the classical solutions. We study holographic correlation functions of scalar operator deformations to a certain 5-dimensional conformal field theory where the operators share the same scaling dimension ∆ = 3

Einstein-scalar-U(2) gauge field theory is considered in a spacetime characterized by $$\alpha $$ and z, which are the hyperscaling violation factor and the dynamical critical exponent, respectively. We consider a dual fluid system of such a gravity theory characterized by temperature T and chemical potential $$\mu $$ . It turns out that there is a superfluid phase transition where a vector order parameter appears which breaks SO(3) global rotation symmetry of the dual fluid system when the chem