• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.1179-1185
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• 2003

시뮬레이션 상의 입력모델에 대한 기존의 연구는 과거의 자료를 바탕으로 선형의 모수적인 (parametric) 모형을 개발하는데 초점을 두고 있다. 그러나 이 경우에는 입력이 매우 복잡한 형태를 가지면 모수적인 모형을 잦는 것이 불가능해지므로 비모수적인(non-parametric) 접근방법이 절실한 실정이다 예로 인터넷 트래픽 모델의 시뮬레이션 수행시 입력으로 제공되는 단위 시간당 요구되는 웹 페이지의 수 같은 경우 데이터들 간데 종속관계가 매우 심하고 복잡하여 모수적 모형을 세우는데 어려움이 있다. 이러한 시스템들을 시뮬레이션 방법으로 분석 하고자 할 때, 기존의 trace-driven 시뮬레이션 방법이나 모수적 모형을 찾아 다수의 사실적인 시뮬레이션 입력 자료를 확보하는 것은 현실적으로 어려움이 있다. 따라서. 비모수적인 방법으로 다수의 사실적인 시뮬레이션 입력 자료를 생성하는 것이 필요하다. 이러한 비모수적인 방법에 대한 평가기준 설정은 시뮬레이션 상의 입력 모델에 대한 타당성을 제시한다는 점에서 또한 매우 중요하다. 본 논문에서는 붓트스트 랩의 방법중의 하나인 임계값 붓트스트랩을 이용하여 시뮬레이션 입력 자료 생성 방법을 개발하였고 Turing test를 통해 붓스트랩으로 생성산 입력 시나리오를 검증하였다.

• 산업기술연구
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• 제21권A호
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• pp.73-80
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• 2001

Barrier is widely used for synchronization in parallel programs. Since the process arrived earlier than others should wait at the barrier, the total processor utilization decreases. In this paper, to find the sources of the barrier waiting time, parallel programs are executed on the various grain sizes through execution-driven simulations. In simulation studies, we found that even if approximately equal amounts of work are distributed to each processor, all processes may not arrive at a barrier at the same time. The reasons are that the different numbers of cache misses and instructions within partitioned grains result in the difference in arrival time of processors at the barrier.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 학술대회 논문집 전문대학교육위원
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• pp.103-107
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• 2001

In this paper, we have developed a new Force-Display system using wire-tension method. The proposed system is based on the HIR Lab Haptic Rendering library, which calculates the real position and renders the reflecting force data to device rapidly. The system is composed of device based tendon-driven method, controller and Haptic rendering library. The developed system will be used on constructing the dynamical virtual environment. To show the efficiency of our system, we designed simulation program which can display the moving force (attaching, grabbing, rotating) on two virtual point. As the result of the experiment, our proposed system shows much higher resolution and stability than any others.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.284-286
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• 1998

In this paper, the experiment on the dynamic characteristics of arch-type LIM is treated. The LIM has been experimented by using the rotational drum type system, which has a motionless short primary propelling a drum. Tests were performed by a PC-based data acquisition system. The input voltage of LIM driven by PWM inverter involves time harmonics. Therefore, the performance of inverter was analyzed for test and simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.183-188
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• 2001

In this paper, we have developed a new Force-Display system using tendon-driven method based multiple DC motors. The proposed system is based on the HIR Lab Haptic library, which calculates the real position and renders the reflecting force data to device rapidly. The system is composed of device based tendon- driving method, high-speed controller and Haptic rendering library. The developed system will be used on constructing the dynamical virtual environment. To show the efficiency of our system, we designed simulation program, which an display the moving force (attaching, grabbing, rotating) on two virtual points. As the result of the experiment, our proposed system shows much higher resolution than any others.

• Computers and Concrete
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• 제28권6호
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• pp.605-619
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• 2021

Building Information Modeling (BIM) models are a powerful tool for preserving and using architectural history. Manually creating information models for such a significant number and variety of architectural monuments as Dong drum towers is challenging. The building logic based on "actual measurement construction" was investigated using the metamodel idea, and a metamodel-based automated modeling approach for the wood framework of Dong drum towers was presented utilizing programmable algorithms. Metamodels of fundamental frame kinds were also constructed. Case studies were used to verify the automated modeling's correctness, completeness, and efficiency using metamodel. The results suggest that, compared to manual modeling, automated modeling using metamodel may enhance the model's integrity and correctness by 5-10% while also reducing time efficiency by 10-20%. Metamodel and construction logic offer a novel way to investigate data-driven autonomous information-based modeling.

• ETRI Journal
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• 제45권4호
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• pp.690-703
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• 2023

Multistage amplifiers have become appropriate choices for high-speed electronics and data conversion. Because of the large number of high-impedance nodes, frequency compensation has become the biggest challenge in the design of multistage amplifiers. The new compensation technique in this study uses two differential stages to organize feedforward and feedback paths. Five Miller loops and a 500-pF load capacitor are driven by just two tiny compensating capacitors, each with a capacitance of less than 10 pF. The symbolic transfer function is calculated to estimate the circuit dynamics and HSPICE and TSMC 0.18 ㎛. CMOS technology is used to simulate the proposed five-stage amplifier. A straightforward iterative approach is also used to optimize the circuit parameters given a known cost function. According to simulation and mathematical results, the proposed structure has a DC gain of 190 dB, a gain bandwidth product of 15 MHz, a phase margin of 89°, and a power dissipation of 590 ㎼.

• 한국지반공학회논문집
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• 제23권12호
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• pp.61-73
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• 2007

본 논문에서는 국내 하중저항계수설계법 개발의 일환으로 구조물기초설계기준에 적용된 항타강관말뚝의 두 정역학적 지지력공식에 대하여 대표적인 신뢰성분석기법인 일차신뢰도법(FORM)과 몬테카를로 시뮬레이션(MCS)을 이용한 강도 높은 신뢰성해석을 수행하고 그 신뢰성수준을 평가하였다. 두 정역학설계법에 대한 저항편향계수는 대표 측정지지력과 설계지지력을 비교함으로써 평가하였다. 국내 정재하시험 및 지반조사 자료를 수집하여 말뚝의 측정 극한지지력을 결정하였고, 정역학적 지지력공식과 Meyerhof 경험식을 이용하여 설계 극한지지력을 산정하였다. 정확하고 효율적인 신뢰성평가를 위해 일차신뢰도법 및 몬테카를로 시뮬레이션 기반의 컴퓨터 프로그램을 개발하였다. 저항편향계수의 통계치를 이용하여 명시적 형태의 간편법인 평균일계이차모멘트법(MVFOSM)과 개선된 방법인 일차신뢰도법 및 몬테카를로 시뮬레이션에 의한 신뢰성해석을 수행하여 그 결과를 비교하였다. 또한 신뢰성 분석에 대한 주요 확률변수의 영향정도와 민감도를 파악하기 위하여 매개변수연구를 수행하였다.

• 한국통신학회논문지
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• 제31권12B호
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• pp.1028-1036
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• 2006

Energy conservation is an important issue in wireless networks, especially for self-organized, low power, low data-rate impulse-radio ultra-wideband (IR-UWB) networks, where every node is a battery-driven device. To conserve energy, it is necessary to turn node into sleep state when no data exist. This paper addresses the energy consumption analysis of Direct-Sequence (DS) versus Time-Hopping (TH) multiple accesses and two kinds of sleeping protocols (slotted and unslotted) in PHY-MAC for Un networks. We introduce an analytical model for energy consumption or a node in both TH and DS multiple accesses and evaluate the energy consumption comparison between them and also the performance of the proposed sleeping protocols. Simulation results show that the energy consumption per packet of DS case is less than TH case and for slotted sleeping is less than that of unslotted one for bursty load case, but with respect to the load access delay unslotted one consumes less energy, that maximize node lifetime.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2398-2415
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• 2017

Content-Centric Networking (CCN) is a new Internet architecture with routing and caching centered on contents. Through its receiver-driven and connectionless communication model, CCN natively supports the seamless mobility of nodes and scalable content acquisition. In-network caching is one of the core technologies in CCN, and the research of efficient caching scheme becomes increasingly attractive. To address the problem of unbalanced cache load distribution in some existing caching strategies, this paper presents a neighbor cooperation based in-network caching scheme. In this scheme, the node with the highest betweenness centrality in the content delivery path is selected as the central caching node and the area of its ego network is selected as the caching area. When the caching node has no sufficient resource, part of its cached contents will be picked out and transferred to the appropriate neighbor by comprehensively considering the factors, such as available node cache, cache replacement rate and link stability between nodes. Simulation results show that our scheme can effectively enhance the utilization of cache resources and improve cache hit rate and average access cost.