• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
• /
• pp.141-148
• /
• 2004

Coal combustion in an iron ore sintering bed is a key parameter that determines quality of the sintered ores and productivity of the process. In this study, effects of the different types of coal coke and anthracite - on the combustion in the iron ore sintering bed are investigated by modeling and experiment. Fuel characteristics of coke and anthracite are observed through a few basic analysis and thermo-gravimetric analysis. It was found that coke has a higher reactivity than anthracite due to the difference of surface area and density. Those characteristics are reflected to the 1-D unsteady simulation of the iron ore sintering bed. Calculation results show that different reactivity of the fuel can affect the bed combustion, which implies the further investigation should be performed for obtaining optimal combustion conditions in the sintering bed.

• 대한기계학회논문집A
• /
• 제26권2호
• /
• pp.243-253
• /
• 2002

This paper presents the system modeling, analysis, and controller design and implementation for a rotational inverted pendulum system(RIPS), which is an under-actuated system and has the problem of unattainable angular velocity state. A sliding mode controller using the parameterization of both the hyperplane and the compensator fur output feedback is applied to the RIPS. Also, to improve the performance of the control system, a disturbance observer which estimates the disturbance, parameter variation, and some modeling errors of RIPS with less computational effort is used together. The results of simulation and experiment show that the proposed control system has superior performance for disturbance rejection and regulation at certain initial conditions.

• Journal of the Optical Society of Korea
• /
• 제9권2호
• /
• pp.74-78
• /
• 2005

With the fast Q-tensor method, which can model the defect dynamics in a liquid crystal director field, the nucleation and dynamical behavior of defects is modeled. In order to model the defect, hormeotropic aligned liquid crystal cell with step inhomogeneous electrode which has a height of $1\;{\mu}m$ is used. From the simulation, we can observe the nucleation and line of the defect from surface inhomogeneity and the experiment is performed for confirmation. The experimental result is compared with numerical modeling in order to verify the simulation of the defect nucleation.

• 한국융합학회논문지
• /
• 제13권3호
• /
• pp.1-9
• /
• 2022

UML(Unified Modeling Language) 클래스 다이어그램은 시스템의 정적인 측면을 표현하며 분석 및 설계부터 문서화, 테스팅까지 사용된다. 클래스 다이어그램을 이용한 모델링이 소프트웨어 개발에 있어 필수적이지만, 경험이 많지 않은 모델러에게 쉽지 않은 작업이다. 도메인 카테고리별로 분류된 클래스 다이어그램 데이터 세트가 제공된다면, 모델링 작업의 생산성을 높일 수 있을 것이다. 본 논문은 클래스 다이어그램 이미지 데이터를 구축하기 위한 자동 분류 기술을 제공한다. 추가 정보 없이 단지 UML 클래스 다이어그램 이미지를 식별하고 도메인 카테고리에 따라 자동 분류한다. 먼저, 웹상에서 수집된 이미지들이 UML 클래스 다이어그램 이미지인지 여부를 판단한다. 그리고, 식별된 클래스 다이어그램 이미지에서 클래스 이름을 추출하여 도메인 카테고리에 따라 분류한다. 제안된 분류 모델은 정밀도, 재현율, F1점수, 정확도에서 각각 100.00%, 95.59%, 97.74%, 97.77%를 달성했으며, 카테고리별 분류에 대한 정확도는 81.1%와 95.2% 사이에 분포한다. 해당 실험에 사용된 클래스 다이어그램 이미지 개수가 충분히 크지 않지만, 도출된 실험 결과는 제안된 자동 분류 방식이 고려할 만한 가치가 있음을 나타낸다.

• Journal of Welding and Joining
• /
• 제24권3호
• /
• pp.34-41
• /
• 2006

The CD (Capacitor Discharge) stud welding utilizes the arc heat and pressure to attach the stud to the workpiece, which consists of the arc. ignition, arcing and pressure welding stages. In order to predict the dynamic behavior of the CD stud welding process, mechanical and electrical models are employed in this work. While the mechanical model estimates the duration of each stage, the electrical model predicts the voltage and current waveforms using the RLC circuit. Effects of process parameters such as the electric components and spring force are analyzed through simulation. It is found that the contact resistance and gap between the stud and base metal influence the tip fusing and arcing duration. The calculated results showed reasonably good agreements with the experiment results.

• 대한전기학회논문지
• /
• 제38권11호
• /
• pp.950-957
• /
• 1989

We have shown how unstructured modeling was used to derive a general stability condition in Part 1. In Part 2, we focus on the particular dynamics (structured modiling) of the robot manipulator and environment. Using rigid body dynamics, the stability condition for the direct drive robots has been achieved in terms of the Jacobian and robot tracking controller. Combining the structured and unstructured modeling, a stability condition for a particular application can be obtained. This approach has been used to analyze compliant motion on the University of Minnesota robot using a feedforward torque controller. We have obtained a stability condition for this application. Through both simulation and experiment, the sufficiency of this condition has been demonstrated. For a sufficient stability condition, recall that if the condition is satified, then the stability is guaranteed` however, if the condition is violated, no conclusion can be made.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.1092-1094
• /
• 2005

This paper deal with the efficiency evaluations in a Synchronous reluctance motor(SynRM) Vs. PMASynRM using a coupled transient finite element method(FEM) and preisach modeling, which is presented to analyze the characteristics under the effect of saturation and hysteresis loss. The focus of this paper is the efficiency evaluation relative to hysteresis loss, copper loss, etc. on the basis of load condition in a SynRM and PMASynRM. Computer simulation and experiment at result for the efficiency using dynamometer shoe the propriety of the proposed method.

• 한국공작기계학회논문집
• /
• 제11권4호
• /
• pp.89-96
• /
• 2002

This paper aims to develop an intelligent model for predicting top-bead width for the robotic GMA(Gas Metal Arc) welding process using BP(Back-propagation) neural network and multiple regression analysis. Firstly, based on experimental data, the basic factors affecting top-bead width are identified. Then BP neural network model and multiple regression models of top-bead width are established. The modeling methods and procedure are explained. The developed models are then verified by data obtained from the additional experiment and the predictive behaviors of the two kind of models are compared and analysed. Finally the modeling methods, predictive behaviors md the advantages of each models are discussed.

• 경영과학
• /
• 제28권1호
• /
• pp.91-105
• /
• 2011

Among various types of creativity, team creativity has been always receiving attention from both practitioners and researchers because most of works are done in a team format in organizations. Therefore, it would be the best way for corporate performance to increase when team creativity is managed carefully to increase in a steadfast way. Though there are lots of ways to grow team creativity, this study explores the issue of increasing the team creativity by adopting CMC (computer-mediated communication) and exploration and exploitation, which were studied separately, but never analyzed together in the same research framework. Experiments to prove the validity of the research questions are based on ABM (Agent-Based Modeling) simulation. Netlogo language was adopted to build a prototype engine for the simulation engine. Experiment results revealed that in the short-term, both broad CMC mode with high exploration and exploitation, and local CMC mode with high exploration and exploitation result in higher team creativity than other types of combination. However, in the long run, broad CMC mode yields higher team creativity level than local CMC mode.

• 대한화학회지
• /
• 제43권2호
• /
• pp.156-160
• /
• 1999

메탄-산소를 아르곤으로 희석한 혼합기체의 점화 과정을 1516-1937K 온도 범위에서 반사 충격파를 이용하여 고찰하였다. 메탄 기체의 점화 지연 시간은 충격관 끝에서 5.0 cm 떨어진 곳에서의 압력 변화 및 광 방출을 측정하여 구하였으며, 각 혼합기체의 농도 의존도 및 온도 의존도에 관한 실험식을 구할 수 있었다. 메탄 산화 과정에 관한 실험 결과를 설명하기 위해 GRI 1.2 메카니즘을 이용한 컴퓨터 모의 실험을 수행하였다.