딥 러닝을 이용한 그래핀 전계 트랜지스터의 고주파 특성 최적화

MasterThe possibility of a novel design of the gate to increase radio-frequency (RF) properties of graphene filed-effect transistors (GFETs) that use graphene pseudo-optics by using a deep learning (DL) was explored. The transmission probabilities for arbitrary gate shapes were calculated by using the finite-difference-time-domain method for massless Dirac fermions and used to train a deep learning. The trained DL predicts the trajectories of massless Dirac fermions according to graphene pseudo-optics. Furthermore, the trained DL can design an optimized gate shape for a targeted graphene pseudo-optic response that increases RF properties of GFETs. The DL-designed GFET has the cutoff frequency f_T=46 GHz and the maximum oscillation frequency f_max=49 GHz, and the conventional GFET has f_T=33.7 GHz and f_max=7.8 GHz with gate length L_g=300 nm. The results showed that the trained DL can increase RF properties of GFETs and solve the existing problem that GFETs have much lower f_max than f_T

딥러닝을 이용한 고주파용 그래핀 전계 트랜지스터의 게이트 구조 디자인

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Simulation Environment of DEVS Models using MATLAB/Simulink

The DEVS (Discrete Event Systems Specification) formalism supports specification of discrete event models in a hierarchical modular manner. MATLAB/Simulink is widely used for modeling, simulating and analyzing continuous and discrete time systems. This paper proposes a realization of the DEVS formalism in MATLAB/ Simulink. The proposed design enables to use a great amount of mathematical packages and functions included in MATLAB /Simulink. The design is also employed as real time simulation and hybrid system simulation which is a mixture of continuous systems and discrete event systems. The paper introduces Simulink-DEVS model, in which a simulation algorithm is embedded. The model consists of a Simulink-atomic model and a Simulink-coupled model. In addition, the time advance algorithm to simulate the model is suggested. The algorithm handles the time synchronization and the accommodation of different concepts specific to continuous and discrete event models. Two experimental results are presented for a pure discrete event model and a hybrid model

Realization of DEVS formalism in MATLAB/Simulink

학위논문(석사) - 한국과학기술원 : 전기및전자공학전공, 2008.2, [ iv, 66 p. ]한국과학기술원 : 전기및전자공학전공

교전급 수준의 국방 시스템을 위한 전투 개체 기반의 모델링 및 시뮬레이션 방법론 연구

학위논문(박사) - 한국과학기술원 : 전기및전자공학과, 2014.2, [ vii, 78 p. ]Many countries are promoting a revolution in military affairs (RMA) or a military reform plan (MRP) in preparation for future warfare. One of the concrete grounds driving such a plan and revolution is that the information technology provides unprecedented applications for the development of next-generation platforms or weapons, such as stealth fighters, guided weapons, or mobile countermeasures Since it requires tremendous time and cost to construct these combat platforms/weapons, performance analysis reflecting military requirements and tactical development for their effective fulfillment are consistently needed from the beginning of the construction. Modeling and simulation (M&S) is devised to take advantage of these opportunities and accompanying M&S techniques have matured to the point where they are useful. As with all M&S applications, the success of defense M&S relies on determining the exact target system to be modeled and understanding several challenges, all drawn from military experience, that are necessary for the M&S development.Our target system, in this dissertation, is an individual combat entity (e.g., a next-generation platform or weapon) for an engagement level combat simulation. Thus, we propose combat entity M&S methodology for engagement level defense systems. To achieve above requisites, this dissertation centers on four issues: 1) conceptual model design, 2) detailed model design, 3) model simulation, and 4) simulation experimentation. In detail, we, first, propose a two-dimensional (2-D) model partition method for conceptual modeling of the combat entity, which partitions it depending on the model scope horizontally and the level of detail vertically. The proposed method guarantees transparent simplification of the combat entity and facilitates flexible model composition when simulating in the centralized as well as the distributed environments. Second, we provide the detailed model design on the basis of the DEVS (Discrete event syste...한국과학기술원 : 전기및전자공학과