• 전자공학회논문지D
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• 제36D권1호
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• pp.83-89
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• 1999

알파 입자의 입사에 의하여 생성된 전하중 접합으로 수집되는 전하량을 예측할 수 있는 통합 모델을 개발하였다. 이 모델은 funneling과 diffusion에 의한 전하 수집 현상을 모두 고려함으로써 접합 면적, 접합 전압 알파 입자의 입사 에너지, 입사 각도, 입사점의 위치, 그리고 접합간 격리에 사용되는 트랜치 산화막 깊이의 변화에 따른 수집전하량의 변화를 정확하게 예측할 수 있다.

• 한국광학회:학술대회논문집
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• 한국광학회 2008년도 하계학술발표회 논문집
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• pp.215-216
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• 2008

Electricity unified field is described based on magnetic theory. Maxwell Einstein Lorentz Equation & pair particle photon model was introduced for Photonics. Refractive index is calculated as deceleration and deflection of photon due to photo-induced surface magnetism. MEL equation was proved with magneto-jet assumption.

• 한국가시화정보학회지
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• 제15권1호
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• pp.32-40
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• 2017

Interaction between fluid and a rigid object is frequently observed in everyday life. However, it is difficult to simulate their interaction as the medium and the object have different representations. One of the challenging issues arises especially in handling deformation of the object visually as well as rendering haptic feedback. In this paper, we propose a real-time simulation technique for multimodal interaction between particle-based fluids and soluble solids. We have developed the dissolution behavior model of solids, which is discretized based on the idea of smoothed particle hydrodynamics, and the changes in physical properties accompanying dissolution is immediately reflected to the object. The user is allowed to intervene in the simulation environment anytime by manipulating the solid object, where both visual and haptic feedback are delivered to the user on the fly. For immersive visualization, we also adopt the screen space fluid rendering technique which can balance realism and performance.

• 한국진공학회지
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• 제18권3호
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• pp.151-163
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• 2009

유체 모델을 기반으로 하는 국내의 유도 결합 플라즈마원의 시뮬레이터 개발 현황을 정리하였다. 전체 시뮬레이터를 구성하는 각 부분으로서, 전자 가열, 하전 입자 및 중성종 수송, sheath를 포함한 표면 반응, 그리고 GUI (Graphic User Interface) 및 전후처리기 등의 순으로 설명되었다. 현재까지 시뮬레이터에 구현된 화학 반응 데이터와 swarm 데이터도 정리하여 보았고, 앞으로의 개발 방향을 전망하여 보았다.

• Computers and Concrete
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• 제26권6호
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• pp.505-513
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• 2020

Grading of aggregate influences significantly almost all of the concrete performances. The purpose of this paper is to propose practicable equations that express the optimized total aggregate gradation, by weight or by number of particles in a concrete mix. The principle is based on the fractal feature of the grading of combined aggregate in a solid skeleton of concrete. Therefore, equations are derived based on the so-called fractal dimension of the grain size distribution of aggregates. Obtained model was then applied in such a way a correlation between some properties of the dry concrete mix and the fractal dimension of the aggregate gradation has been built. This demonstrates that the parameter fractal dimension is an efficacious tool to establish a unified model to study the solid phase of concrete in order to design aggregate gradation to meet certain requirements or even to predict some characteristics of the dry concrete mixture.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권2호
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• pp.723-743
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• 2016

Indoor positioning is considered an enabler for a variety of applications, the demand for an indoor positioning service has also been accelerated. That is because that people spend most of their time indoor environment. Meanwhile, the smartphone integrated powerful camera is an efficient platform for navigation and positioning. However, for high accuracy indoor positioning by using a smartphone, there are two constraints that includes: (1) limited computational and memory resources of smartphone; (2) users' moving in large buildings. To address those issues, this paper uses the TC-OFDM for calculating the coarse positioning information includes horizontal and altitude information for assisting smartphone camera-based positioning. Moreover, a unified representation model of image features under variety of scenarios whose name is FAST-SURF is established for computing the fine location. Finally, an optimization marginalized particle filter is proposed for fusing the positioning information from TC-OFDM and images. The experimental result shows that the wide location detection accuracy is 0.823 m (1σ) at horizontal and 0.5 m at vertical. Comparing to the WiFi-based and ibeacon-based positioning methods, our method is powerful while being easy to be deployed and optimized.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권1호
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• pp.135-142
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• 2012

In this paper, optimal selection of the unified power flow controller (UPFC) damping controller parameters in order to improve the power system dynamic response and its stability based on two modified intelligent algorithms have been proposed. These algorithms are based on a modified intelligent particle swarm optimization (PSO) and continuous genetic algorithm (GA). After extraction of UPFC dynamic model, intelligent PSO and genetic algorithms are used to select the effective feedback signal of the damping controller; then, to compare the performance of the proposed UPFC controller in damping the critical modes of a single-machine infinite-bus (SMIB) power system, the simulation results are presented. The comparison shows the good performance of both presented PSO and genetic algorithms in an optimal selection of UPFC damping controller parameters and damping oscillations.

• 한국컴퓨터정보학회논문지
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• 제29권6호
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• pp.23-29
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• 2024

본 논문에서는 옷감과 입자 기반 유체 해법인 SPH(Smoothed particle hydrodynamics)를 이용한 액체 간의 상호작용으로 표현되는 다공성 흐름(Pore flow), 흡수, 방출 그리고 확산 효과를 GPU 기반으로 빠르게 표현할 수 있는 방법을 제안한다: 1) 옷감-액체의 상호작용에 의해 표현되는 다양한 물리적 효과를 GPU 기반으로 표현할 수 있는 통합형 프레임워크, 2) SPH 기반으로 노드의 포화도를 효율적으로 계산하고 이를 주변 Porous 입자들로 전달하는 방법, 3) 유체 흡수 및 방출 방향을 안정적으로 계산하기 위해 다르시 법칙(Darcy's law)을 기반으로 안정성을 개선시키는 방법, 4) Porous 입자들로 흡수되는 과정에서 유체의 흐름 방향에 따라 흡수되는 양을 조절하는 방법, 마지막으로 5) SPH 입자의 최대 질량이 넘지 않도록 방출할 수 있는 방법을 제시한다. 제안하는 방식의 가장 큰 장점은 모든 연산이 GPU에서 계산되고 동작하기 때문에 빠르게 옷감과 유체의 상호작용으로 표현되는 다공성 재질, 다공성 흐름, 흡수, 반사, 확산 등을 모델링할 수 있다.

• 대기
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• 제34권2호
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• pp.217-231
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• 2024

The Korea Integrated Model (KIM)-based real-time volcanic ash dispersion prediction system, which employs the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, has been developed to quantitatively predict volcanic ash dispersion in East Asia and the Northwest Pacific airspace. This system, known as KIM-HYSPLIT, automatically generates forecasts for the vertical and horizontal spread of volcanic ash up to 72 hours. These forecasts are initiated upon the receipt of a Volcanic Ash Advisory (VAA) from the Tokyo Volcanic Ash Advisory Center by the server at the Korea Meteorological Administration (KMA). This system equips KMA forecasters with diverse volcanic ash prediction information, complemented by the Unified Model (UM)-based HYSPLIT (UM-HYSPLIT) system. Extensive experiments have been conducted using KIM-HYSPLIT across 128 different volcanic scenarios, along with qualitative comparisons with UM-HYSPLIT. The results indicate that the ash direction predictions from KIM-HYSPLIT are consistent with those from UM-HYSPLIT. However, there are slight differences in the horizontal extent and movement speed of the volcanic ash. Additionally, quantitative verifications of the KIM-HYSPLIT forecasts have been performed, including threat score evaluations, based on recent eruption cases. On average, the KIMHYSPLIT forecasts for 6 and 12 hours show better quantitative alignment with the VAA forecasts compared to UM-HYSPLIT. Nevertheless, both models tend to predict a broader horizontal spread of the ash cloud than indicated in the VAA forecasts, particularly noticeable in the 6-hour forecast period.

• 과학교육연구지
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• 제44권1호
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• pp.112-121
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• 2020

광전효과는 빛의 입자성을 설명하는 대표적인 현상으로 고전 물리학에서 현대물리학으로의 전환을 이끈 중요한 주제이다. 중등교육 과정에서도 광전 효과를 중요하게 다루고는 있지만, '빛의 세기'에 대한 설명이 전자기파의 세기에 대한 설명과 달라서 교사나 학생들이 종종 혼란을 겪고 있다. 이에 본 연구에서는 현대물리 교재의 광전효과 단원에서 '빛의 세기'를 어떻게 설명하고 있는지 분석하였다. 널리 사용되는 10종의 현대물리 교재를 분석한 결과 '빛의 세기'가 크게 두 가지 유형으로 설명되고 있었으며, 특히 한 교재 내에서 두 가지 다른 유형의 표현이 모두 나타나기도 하였다. 연구자들은 본 연구의 결과를 바탕으로 향후 광전효과를 기술하는 데 있어서 몇 가지 유의점을 제안하였다.