• 한국CDE학회논문집
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• 제15권4호
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• pp.279-288
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• 2010

In this paper, a DEVS(Discrete EVent Systems Specification)-HLA(High Level Architecture) interface was developed in order to perform the simulation using the combined discrete event and discrete time simulation model architecture in a distributed environment. The developed interface connects the combined simulation model with the HLA/RTI(Run-Time Infrastructure) which is an international standard middleware for distributed simulation. The interface consists of an interface model, a model interpreter, and a distributed environment interpreter. The interface model was defined by using the combined simulation architecture in order to easily connect the existing combined simulation model without modification with the HLA/RTI. The model interpreter takes charge of data transmission between the interface model and the combined simulation model. The distributed environment interpreter takes charge of data transmission between the interface model and the HLA/RTI. To evaluate the applicability of the developed interface, it was applied to the diving simulation of a submarine in a distributed environment. The result shows that a simulation result in a distributed environment using the interface is the same to the result in a single computing environment.

• 한국정보통신학회논문지
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• 제16권11호
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• pp.2495-2502
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• 2012

이 논문은 전하펌프를 추가하여 루프필터에서 공정에 따라 값이 크게 변하는 저항을 없앤 새로운 구조의 위상고정루프를 보여준다. 두 번째 전하펌프가 기존의 루프 필터 저항 역할을 하도록 하였다. 두 개의 전하펌프 출력은 공정 변화에 같은 방향으로 움직이므로 위상고정루프의 동작이 공정 변화 영향을 적게 받게 된다. 공정 조건(SS/TT/FF)에 따른 시뮬레이션 결과는 제안된 구조가 공정 변화에 무관하게 동작함을 보여주고 있다. 제안된 구조는 1.8V $0.18{\mu}m$ CMOS 공정의 파라미터를 이용하여 HSPICE로 시뮬레이션을 수행하였고 회로의 동작을 검증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1687-1689
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• 1998

In this work, the behaviours of conducting wire type particles within the coaxial electrode gap energized with high ac voltage have been systematically investigated using charge simulation method. For this, spheroidal charge is adopted as a image charge for the CSM analysis in order to calculate the acquired charge of the particles which are erected on the surface of the outer electrode. For this purpose, the effects of the lengths and diameters of Cu, Al particles in gas insulated system have been studied by a numerical computation and particle lifting voltage, lifting field, breakdown voltage, acquired charge and travelling distance have been considered. From this, we understand that the particle behaviours have different characteristics according to the particle lengths and diameters. And a possible countermeasure, based on the proposed simulation, has been provided with a view to estimating the flashover voltage of $SF_6$ gas under the 1 atm.

• 전자공학회논문지S
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• 제35S권1호
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• pp.14-22
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• 1998

The Mathematic model of bit synchronization charge-pump Phase Locked Loop (PLL) is presented which takes into account the aperiodic reference pulses and the leakage current of the loop filter. We derive theoreitcal static phase error, overload and stability of bit synchronization charge-pump PLL using presented model and compare it with one of the conventional charge-pump PLL model. We can analysis bit synchronization charge-pump PLL exactly because our model takes into account the leakage current of the loop filter and aperiodic input data which are the charateristics of bit synchronization charge-pump PLL. We also verify it using HSPICE simulation with a bity synchronizer circuit.

• 화약ㆍ발파
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• 제36권3호
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• pp.19-28
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• 2018

지진 및 예기치 못한 외부하중에 의하여 손상된 구조물의 경우, 2차적인 국부손상 및 이로 인한 붕괴가 발생할 수 있어 발파해체공법에 의한 철거가 우선시 고려되고 있다. 특히 철재로 이루어진 교량 및 구조물의 경우 성형폭약을 이용한 발파해체기법이 적용되어 오고 있다. 최근에는 구리판을 드로잉 가공한 성형폭약용기에 상용폭약을 장전하여 두꺼운 철판을 절단하는 발파공법이 제안되었다. 본 연구에서는 LS-DYNA 동해석소프트웨어를 이용하여 드로잉 가공 성형폭약용기와 상용폭약을 적용한 25mm 두께의 철판 절단실험발파를 모사하고 절단형상 및 깊이를 비교분석하여 적용구성모델의 입력변수를 결정하였다. 해석모델을 이용하여 폭약의 종류, 구리 라이너의 두께, 이격거리의 변화에 따른 철판 내 관통깊이 및 관통 폭을 분석하였다.

• 에너지공학
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• 제20권4호
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• pp.278-285
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• 2011

본 연구에서는 리튬이온 전지의 충 방전 특성에 관한 모델링과 전산모사를 수행하였다. 전지의 시스템 구성은 단순화된 2차원 형태의 단일셀에 대하여 모델링하였고, 공학적 편미분방정식 풀이자인 FEMLAB을 이용하여 288 K와 318 K 범위내에서 충방전 특성에 대한 열적 모델링을 수행하였다. 모델링에 채택한 물성치 변수들에 대하여 온도특성을 고려하였으며, 이를 통하여 전지의 특징적인 충방전의 사이클 변화와 충방전 전하량의 변화를 체계적으로 전산모사하였다. 그 결과 충방전 속도에 상관없이 충방전의 주기가 온도가 낮아질수록 짧아짐을 정량적으로 해석할 수 있었다. 이에 부가하여 전지내에서 리튬이온의 물질전달 현상을 해석하여, 전지의 충방전 특성과의 상관관계를 고찰하였다.

• 한국분무공학회지
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• 제29권1호
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• pp.1-6
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• 2024

This paper is a numerical analysis study for evaluating the energy efficiency of electric vehicles. Currently, the methods for testing and evaluating the energy consumption efficiency of electric vehicles have limitations such as resources and time. Therefore, there is a need for research on developing models to predict the energy consumption efficiency of electric vehicles. In this study, a numerical analysis research is conducted to predict the energy efficiency of electric vehicles using a vehicle dynamics numerical analysis model. To validate the accuracy of the simulation model, it is compared the results of dynamometer tests with the simulation results and used the Unified Diagnostic Services (UDS) protocol to acquire internal data from the electric vehicle. It is ensured the reliability of the simulation model by comparing data such as motor speed, battery voltage, current, state of charge (SOC), regenerative braking power generation, and total driving distance of the test vehicle with dynamometer test data and simulation model results.

• 전기의세계
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• 제30권9호
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• pp.589-593
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• 1981

Anumerical method for the calculation of electric fields with two-dielectric media is described. The basis of the method is the use of fictitious charges as a particular solution of Laplace's (and Poisson's) equations. Simple examples were chosen for the explanation of the method and the close agreement between calculated and analytical values was obtained. It has been shown that the charge simulation method is better in calculation time and accuracy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1987-1989
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• 2000

In this paper, electric field distribution of dielectric sphere considering surface or volume resistivity is analysed by the use of rotational symmetric charge simulation method. We applied three methods such as ${\alpha},{\beta}$ modified $\beta$ method to check electric field calculation error. We find f method and modified $\beta$ method are suitable to simulate volume and surface resistivity respectively.

• 인터넷정보학회논문지
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• 제21권5호
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• pp.39-48
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• 2020

Recently, the study and development of environment-friendly energy technique have increased in worldwide due to environmental pollution and energy resources problems. In vehicle industry, the development of electric vehicle(EV) is now on progress, and also, many other governments support the study and development and make an effort for EV to become widely available. In addition, though they strive to construct the EV infra such as a charge station for EV, the techniques related to managing charge demand and peak power are not enough. The standard of EV communication has been already established as ISO/IEC 15118, however, most of implemented EVs and EV charge stations do not support any communication between each of them. In this paper, an improved slow charge scheme for non-communication EVs is proposed and designed by using predicting charge demand. The proposed scheme consists of distributed charge model and charge demand prediction. The distributed charge model is designed to manage to distribute charge power depending on available charge power and charge demand. The charge demand prediction is designed to be used in the distributed charge model. The proposed scheme is based on the collected data which were from EV slow charge station in business building during the past 1 year. The system-level simulation results show that the waiting time of EV and the charge fee of the proposed scheme are better than those of the conventional scheme.