Earticle

TRISO (Tri-Isotropic)-coated fuel particle is widely applied due to its higher stability at high temperature and its efficient retention capability for fission products in the HTGR (high temperature gas-cooled reactor), one of the highly efficient Generation IV reactors. The typical ball-type TRISO-coated fuel particle with a diameter of about 1 mm is composed of a nuclear fuel particle as a kernel and of outer coating layers. The coating layers consist of a buffer PyC, inner PyC, SiC, and outer PyC layer. In this study, a digital image processing algorithm is proposed to automatically measure the thickness of the coating layers. An FBP (filtered backprojection) algorithm was applied to reconstruct the CT image using virtual X-ray radiographic images for a simulated TRISO-coated fuel particle. The automatic measurement algorithm was developed to measure the coating thickness for the reconstructed image with noises. The boundary lines were automatically detected, then the coating thickness was circularly by the algorithm. The simulation result showed that the measurement error rate was less than 1.4%.

본 연구에서는 정상 상태의 국내 금광산 선광플랜트의 분쇄/분급 공정을 전산모사 하였다. 분쇄 일지수와 에 너지 기반 경험적 모델을 활용하여 분쇄 산물의 80% 입도를 예측하였다. 실제 선광장의 볼밀 크기, 회전 속도, 볼 충전 율 등이 분쇄 모델에 적용되었다. 스파이럴 분급기는 Stoke 법칙, 습식싸이클론은 Plitt model을 이용하여 각 분급기의 분급입도 (d50c)를 산출하였다. 모델 및 변수들을 선광공정 시뮬레이터인 USIMPAC에 입력하여 공정의 전체 물질 수 지 및 입도분포를 예측하였다. 예측된 광액농도와 입도분포가 실제 결과와 높은 상관계수로 일치함을 확인하였다.

This study on simulation was conducted for steady state grinding and classification processes in domestic gold ore mineral processing plant. In the grinding process, the 80% particle size of the ball mill products were predicted using work index and energy based empirical model. The actual operational parameters such as the size of ball mill, rotating speed and ball filling rate were applied to grinding model. The cut size (d50c) of spiral classifier and hydrocyclone were calculated using Stoke’s law and Plitt model, respectively. The models and variables were input to USIMPAC, a simulator for mineral processing, to predict the overall mass balance and particle size distribution of the process. It was confirmed that the predicted pulp density and the particle size distribution were in good agreement with the actual results from a high correlation coefficient.

일반적으로 초고속 네트워크에서 실행되는 분산 시스템의 데이터 전달처리 효율은 시스템 구조 및 데이터의 전달처리 시스템에 의존한다. 분산 환경을 이용한 실시간 분산 시뮬레이션 시스템은 데이터전달처리의 실시간성과 시스템의 신뢰성 보장을 위하여 데이터 전달처리 시스템에 의하여 요구된 성능을 만족하고자 하였다. 그러나 실시간 시뮬레이션 시스템에 적용된 클라이언트/서버 기반의 데이터 전달처리 시스템은 시스템의 안정성 및 시스템의 변경에 따른 확장성과 유지보수성 확보가 어려웠다. 따라서 기존의 데이터 전달처리 시스템의 문제점을 해결하기 위하여 새로운 데이터 전달처리 시스템이 필요하다. 본 논문에서는 기존의 실시간 시뮬레이션 시스템을 분석하여 시스템 개선방향을 제시하고, 시스템 확장성, 상호운용성, 재사용성 및 유지보수성을 위하여 소프트웨어 디자인 패턴을 적용한 새로운 실시간 데이터 전달처리 시스템을 제안한다.

Usually, The data transmission processing efficiency of the distributed system running on high speed networks depends on the system architecture and the data transmission processing system. In order to secure the real-time rate and the system reliability, the real-time distributed simulation system on the distributed environment has tried to satisfy the performance required by the data transmission processing system. However, the client/server-based data transmission processing system in the real-time simulation system has been difficult to satisfy the system stability, extensibility and maintenability, especially when system changes. So, it is natural to study another improved data transmission processing system to solve the problems at the existing real-time simulation system. After analyzing the existing real-time simulation system, this paper will propose the improved real-time data transmission system by using Software Design Pattern, which enhances extensibility, interoperability, reusability and maintenability of the system.

It needs to accumulate a store of know-how on the design, precision processing and appraisement for metering pump which is a kind of gear pump fer synthetic fibers. But the period and cost fur development is not effective, because designers experience many trial and error for the pump design and manufacturing process. Therefore, in order to curtail the period and cut down expenses, the analysis and simulation system is required for a designed metering pump. In this study, the pump simulation software was developed with the visual C++ language and the image processing algorithm, and was investigated through a discharge test for the planetary gear type metering pump.

본 연구에서는 수학적 모델링 및 전산 모사를 통해 국내 금은광산 선광플랜트 볼 밀 분쇄산물의 입도 분포를 예측하였다. 물질 수지 방정식에 기초한 Population Balance Model을 활용하여 볼 밀 분쇄산물의 입도 분포를 예측하 고자 하였다. 회분식 분쇄 실험을 수행한 후, 이를 국내 금은광산 선광플랜트 볼 밀의 분쇄 조건으로 스케일업하였다. 스케일업된 결과를 선광공정 상용 소프트웨어인 USIM-PAC으로 모델링 및 전산 모사하였다. 전산 모사 결과와 실제 선광플랜트 볼 밀 분쇄산물의 입도 모두 D80 기준 0.191 mm로 산출되었으며, 결정계수 또한 0.995로 산출되어 선광플 랜트 볼 밀을 전산 모사 가능함을 확인하였다. 이를 근거로 선광플랜트 내 볼 밀의 분쇄 조건 변화에 따른 분쇄산물의 입도 분포를 예측할 수 있을 것으로 기대된다.

In this study, mathematical modeling and computational simulation were used to predict the particle size distribution of ball mill product in domestic gold silver mineral processing plant. Particle size distribution of ball mill product was predicted using Population Balance Model based on mass balance equation. Batch grinding tests were performed, then scaled-up under grinding condition of ball mill in domestic gold silver mineral processing plant. Scaled-up results were modeled and simulated by using USIM-PAC, a commercial software for mineral processing. Both 80% passing particle size of computational simulation result and actual particle size distribution were calculated as 0.206 mm, also coefficient of determination was calculated to be 0.998. Therefore, it was confirmed to the validation of simulation. Based on these results, it is expected to predict particle size distribution of ball mill in domestic gold/silver mineral processing plant according to the change of grinding condition.

Two of fundamental approaches that can be used to understand ion-solid interaction are Monte Carlo (MC) and Molecular Dynamic (MD) simulations. For the simplicity of simulation Monte Carlo simulation method is widely preferred. In this paper, basic consideration and algorithm of Monte Carlo simulation will be presented as well as simulation results. Sputtering caused by incident ion beam will be discussed with distribution of sputtered particles and their energy distributions. Redeposition of sputtered particles that are experienced refraction at the substrate-vacuum interface additionally presented. In addition, reflection of incident ions with reflection coefficient will be presented together with spatial and energy distributions. This Monte Carlo simulation will be useful in simulating and describing ion beam related processes such as Ion beam induced deposition/etching process, local nano-scale distribution of focused ion beam implanted ions, and ion microscope imaging process etc.

커넥티드 카에서 발생하는 실시간 데이터 처리를 위한 엣지–커넥티드 카 환경에서 웹소켓 통신 연구가 활발히 진행 되고 있다. 그러나 웹소켓은 연결 유지, 고정된 연결의 특성으로 대용량 데이터 처리를 위한 분산 엣지 환경을 구성 하는데, 구조적 한계가 있다. 기존 연구는 세션 공유, 아파치 카프카 통신을 활용했으나, 이는 추가 리소스와 종속 성, 확장성 문제가 존재한다. 본 연구는 실시간성, 확장성, 낮은 리소스를 보장하는 새로운 웹소켓 기반 데이터 통신 기법을 제안하며. 이를 Digital Twin 모델에 적용하였고 차량 충돌 이벤트 처리를 통해 제안된 기법의 효율성을 검증했다.

Research on WebSocket communication in edge-connected car environments is ongoing. WebSockets have structural limits for large data handling due to persistent and fixed connections. Previous approaches using session sharing and Apache Kafka faced scalability and resource dependency issues. This study proposes a new WebSocket-based technique that ensures real-time, scalable, and resource-efficient data communication. It has been applied to the Digital Twin model, proving its effectiveness through vehicle collision event handling.

The paper studied hypoid gear CNC machining theory and simulation processing. Through construct a simulation case of hypoid gear machining system, optimization processing parameters for the main aspects, verify the effectiveness of pre-correction system.

Fluid simulation is an important application of High Performance Computing. The hybrid atomistic-continuum coupling fluid simulation can effectively handle the contradictory of the reduction of the simulation scale and the increase of the computation load when trying to improve the accuracy. The pre-processing procedure of the coupling simulation is quite important in the whole simulation process and requires the support of an efficient, user-friendly interface. Under the demand of efficient coupling fluid simulation, in this paper we design and implement a visualized pre-processing framework HACP2 based on SALOME, for the unified molecular dynamic-computational fluid dynamics modeling and apply it into the coupling simulation process. The experimental verification indicates that our HACP2 framework can offer efficient, easy-to-use pre-processing for the hybrid atomistic-continuum coupling simulation, and effectively improve the efficiency of the coupling simulation.

컴퓨터 구조의 연구 결과, 특정 영역의 하드웨어를 개발하는 과정에서 가격 대 에너지 성능의 획기적인 개선이 이뤄진다고 알려져 있다. 본 논문은 인공신경망(NN)의 추론을 가속화시킬 수 있는 텐서 처리부(TPU) ASIC에 대한 분석 을 수행하였다. 텐서 처리부의 핵심장치는 고속의 연산이 가능한 MAC 행렬곱셈기와 소프트웨어로 관리되는 온칩 메모 리이다. 텐서 처리부의 실행모델은 기존의 CPU와 GPU의 실행모델보다 인공신경망의 반응시간 요구사항을 제대로 충족 시킬 수 있으며, 수많은 MAC과 큰 메모리를 장착함에도 불구하고 면적이 작고 전력 소비가 낮다. 텐서플로우 벤치마크 프레임워크에 대하여 텐서 처리부를 활용함으로써, CPU 또는 GPU보다 높은 성능과 전력 효율을 나타낼 수가 있다. 본 논문에서는 텐서 처리부를 분석하고, 파이썬을 이용하여 모델링한 OpenTPU에 대하여 모의실행을 하였으며, 그 핵 심장치인 행렬 곱셈부에 대한 합성을 시행하였다.

The study of the computer architecture has shown that major improvements in price-to-energy performance stems from domain-specific hardware development. This paper analyzes the tensor processing unit (TPU) ASIC which can accelerate the reasoning of the artificial neural network (NN). The core device of the TPU is a MAC matrix multiplier capable of high-speed operation and software-managed on-chip memory. The execution model of the TPU can meet the reaction time requirements of the artificial neural network better than the existing CPU and the GPU execution models, with the small area and the low power consumption even though it has many MAC and large memory. Utilizing the TPU for the tensor flow benchmark framework, it can achieve higher performance and better power efficiency than the CPU or CPU. In this paper, we analyze TPU, simulate the Python modeled OpenTPU, and synthesize the matrix multiplication unit, which is the key hardware.

스마트폰과 초고속 네트워크에 연결된 스마트폰과 같은 클라이언트는 다양한 위치기반 서비스를 언제 어디 서나 사용할 수 있게 해주고 있다. 이런 환경에서 무선 데이터 방송 시스템은 대규모의 클라이언트들의 다양한 데이 터 요구를 효과적으로 처리할 수 있게 한다. 효율적인 무선 데이터 방송 시스템을 구축하기 위해 다양한 데이터 스케 줄링 기법과 인덱싱 기법이 개발되고 있으나 이러한 기법들을 신속히 평가하기 위한 시뮬레이션 프레임워크의 개발 은 보고된 것이 없다. 본 논문에서는 시뮬레이션 기반의 무선 데이터 방송 시스템 성능 평가를 위한 시뮬레이션 프레 임워크를 설계 및 구현한다. 개발된 프레임워크는 무선 데이터 방송 시스템의 성능을 빠르게 평가할 수 있으며 다양 한 데이터 스케줄링 기법과 인덱싱 기법을 적용할 수 있는 확장성을 가진다.

Smart devices linked to high speed networks enable us to obtain location dependent data at anywhere and anytime. In this environment, a wireless data broadcast system can deal with enormous data request from a great number of clients effectively. In order to set up an efficient wireless data broadcast system, various data scheduling and indexing schemes have been proposed. However, a simulation framework to evaluate the schemes is not reported yet. In this paper, we design and develop a simulation framework for a wireless data broadcast system. The developed simulation framework can evaluate quickly a wireless data broadcast system and has scalability to adopt various data scheduling and indexing schemes for wireless data broadcasting.

진공 시스템의 성능에 대한 밸브 컨덕턴스의 영향은 진공시스템의 설계 최적화를 위해 전산모사 되었다. 본 연구에서는, 전산모사기인 VacSimMulti 에 의한 모델링기구가 제시되었다. 진공 시스템의 설계는 진공 장비의 다양한 산업적 구현을 위해 특정한 프로세스 조건을 충족해야 한다. 진공 밸브의 구조, 길이, 직경 등은 컨덕턴스 영향의 전산모사 변수로서 모델링 되었으며, 직렬 진공 시스템의 배기 밸브 또한, 다양한 크기와 구조로 모델링하여 전산모사 되었다. 밸브 직경의 변화는 도관의 길이의 변화보다 진공특성에 있어 더 유의미한 효과를 보여주었으며 슬릿형의 밸브도관 시스템은 모델링된 밸브구조 중 가장 뛰어난 진공특성을 가지는 것으로 관찰 되었다.

Effect of valve conductance on performance of vacuum system was simulated for optimum design of vacuum system. In this investigation, the feasibility of modeling mechanism for VacSimMulti simulator was proposed. Application specific design of vacuum system is required to meet the particular process conditions for various industrial implementations of vacuum equipments. Geometry and length, diameter of vacuum valve were modeled as simulation modeling variables for conductance effects. Series vacuum system was modeled and simulated with varied dimensions and structures of exhaust valves. Variation of valve diameter showed the more significant effects on vacuum characteristics than that of pipeline length variations. It was also observed that the aperture structure of valve had the superior vacuum characteristics among the modeled systems.

We have developed CUDA-enabled version of a general purpose molecular dynamics simulation code for GPU. Implementation details including parallelization scheme and performance optimization are described. Here we have focused on the non-bonded force calculation because it is most time consuming part in molecular dynamics simulation. Timing results using CUDA-enabled and CPU versions were obtained and compared for a biomolecular system containing 23558 atoms. CUDA-enabled versions were found to be faster than CPU version. This suggests that GPU could be a useful hardware for molecular dynamics simulation.

This paper presents a CFD modeling approach for a 19-rod bundle fuel assembly with spiral semi-cylindrical ribs, which potentially can be used for liquid metal cooled fast reactor, as well as a numerical simulation of flow and thermal behavior under partially blocked conditions. The ribs on fuel rod surface are integrally formed with the cladding to enhance heat transfer while preventing detachment. However, the complex channel geometry presents challenges for grid generation, as using a large number of tetrahedral or polyhedral elements would consume significant computational resources. Therefore, this paper proposes a mesh morphing-based pre-processing method to establish a structured hexahedral mesh for such complex geometry. Using this approach, the 19-rods assembly is analyzed, and the result has been verified by conventional mesh scheme as well as experiment.

This article compares online processing, memory-based processing, and an integrated model of the two, using the empirically observed changes in candidate evaluation during the U.S. presidential election of 2000. The study demonstrates that the online and memory-based processing models, which have often been considered as fundamentally different, are in fact complementary to each other and can be accomodated within a coherent, more comprehensive framework. Also, the simulation result of the study suggests that the integrated model fully captures a motivatied reasoning while the online model and memory-based processing model do not, and that this is the key reason why the integrated model outperforms the other two in accounting for the responsiveness and persistence of candidate evaluation observed in the data.

Polyurethane foams were produced by using a homogenizer as a mixing equipment. Effects of stirring speed on the foam structure were investigated with SEM observations. Variation of the bubble size, density of the foam, compressive strength, and thermal conductivity were studied. A hybrid foam consisting of polyurethane foam and commercial polystyrene foam is produced. Mechanical and thermal properties of the hybrid foam were compared with those of pure polyurethane foam. Advancement of flow front during mold filling was observed by using a digital camcorder. Four types of mold geometry were used for mold filling experiments. Flow during mold filling was analyzed by using a two-dimensional control volume finite element method. Variation of foam density with respect to time was experimentally measured. Creeping flow, uniform density, uniform conversion, and uniform temperature were assumed for the numerical simulation. It was assumed for the numerical analysis that the cavity has thin planar geometry and the viscosity is constant. The theoretical predictions were compared with the experimental results and showed good agreement.

In order to understand the flow behavior of Electrorheological (ER) fluid, dynamic simulation has been intensively performed for the last decade. When the shear flow is applied, it is easy to carry out the simulation with relatively small number of particles because of the periodic boundary condition. For the squeezing flow, however, it is not easy to apply the periodic boundary condition, and the number of particles needs to be increased to simulate the ER system more realistically. For this reason, the simulation of ER fluid under squeezing flow has been mostly performed with some representative chains or with the approximation that severely restricts the flow geometry to reduce the computational load. In this study, Message Passing Interface (MPI), which is one of the most widely-used parallel processing techniques, has been employed in a dynamic simulation of ER fluid under squeezing flow. As the number of particles used in the simulation could be increased significantly, full domain between the electrodes has been covered. The numerical treatment or the approximation used to reduce the computational load has been evaluated for its validity, and was found to be quite effective. As the number of particles is increased, the fluctuation of the normal stress becomes diminished and the prediction in general was found to be qualitatively In good agreement with the experimental results.