• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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• pp.33-38
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• 2004

Molecular modeling of gas permeation through zeolite membranes with/without intercrystalline region was carried out. Molecular dynamics (MD) and Monte Carlo (MC) simulations were performed to estimate the diffusion coefficient and adsorption parameters respectively, and our proposed combined method of molecular simulation techniques with a permeation theory (CMP) was used to estimate gas permeability. The calculated permeability of gases (Ar, He, Ne, $N_2$, $0_2$, $CH_4$) at 301 K for the single crystal membrane model was about one order of magnitude larger than the experiential values, although the dependence on the molecular weight of the permeating species agreed with experiments. On the other hand, the estimated permeability using the diffusivity and adsorption parameters of the intercrystalline region model was in good agreement with the experiments. The consistency between experiments and the estimated values means the importance of considering the intercrystalline region and the validity of CMP method to predict the performance of zeolite membranes.

• 소음진동
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• 제8권3호
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• pp.494-503
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• 1998

In this paper, in order to analyze dynamic characteristics of an automobile steering system consisting of many components, natural frequencies and transfer functions of each component and the total system are found on a FFT analyzer by experiments. Then, the data are transmitted to a commercial package program, CADA-PC. By analyzing the data, the mode shape of each natural frequency and damping values are obtained. Also, the function of a rubber coupling in column and telescoping effects on system are considered. C.A.E commercial programs are used to compare with the results of experiments. For the finite element modeling, I-DEAS is used. Data processing and post processing are operated on NASTRAN and XL, respectively. The ball-bearing and the linkage of shaft with column are modeled by spring element. Stiffness is modified from the results of experiments. The results of those show close agreement. In the mode shape of total system, wheel mode is dominant at lower frequency, while the column mode is main mode at higher. The role of rubber coupling in vibration isolation is clear on mode shape. Telescoping function makes natural frequency of column changed.

• Advances in robotics research
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• 제1권1호
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• pp.61-79
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• 2014

This paper presents theoretical and experimental investigations into the dynamic modelling and characterisation of a two-link flexible manipulator incorporating payload. A planar two-link flexible manipulator that moves in a horizontal plane is considered. A dynamic model of the system is developed using a combined Euler-Lagrange and assumed mode methods, and simulated using Matlab. Experiments are performed on a lab-scaled two-link flexible manipulator for validation of the dynamic model and characterisation of the system. Two system responses namely hub angular position and deflection responses at both links are obtained and analysed in time and frequency domains. The effects of payload on the dynamic characteristics of the flexible manipulator are also studied and discussed. The results show that a close agreement between simulation and experiments is achieved demonstrating an acceptable accuracy of the developed model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1178-1182
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• 2004

This paper presents web-based virtual laboratory system for electronic and digital circuit experiments. Through our virtual laboratory, the learners will be capable of learning the concepts and theories related to circuit experiments and how to operate virtual experimental equipments such as multimeters, function generators, digital oscilloscopes, DC power suppliers and bread board etc. The proposed virtual laboratory system is composed of important components: Principle Classroom to explain the concepts and theories of electronic and digital circuit operations, Simulation Classroom to provide a web-based simulator to the learners, Virtual Experiment Classroom to provide interactive multimedia contents about the syllabus of off-line laboratory class, Assessment Classroom, and Management System. With the aid of the management System every classroom is organically tied together collaboration to achieve maximum learning efficiency. We have obtained several affirmative effects such as high learning standard, reducing the total experimental hours and the damage rate for experimental equipments.

• 한국생산제조학회지
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• 제7권5호
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• pp.134-139
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• 1998

There have been so manu study in the ultra-precision mirror finishing. Already Using system of experiments extract factors effecting surface roughness and find optimal machining conditions in 40${\mu}{\textrm}{m}$, 30${\mu}{\textrm}{m}$, 15${\mu}{\textrm}{m}$ abrasive film. So in this study, Using Abrasive film of 12~3${\mu}{\textrm}{m}$ extract factors effecting surface roughness and results are follows; Factor A(film feed) in 12${\mu}{\textrm}{m}$ and 5${\mu}{\textrm}{m}$ abrasive film, Factor A(film feed) and B(applied force) in 9${\mu}{\textrm}{m}$ abrasive film, Factor C(grinding speed) in 3${\mu}{\textrm}{m}$ abrasive film are main factor effecting surface roughness.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 Asia Navigation Conference
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• pp.167-176
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• 2004

The authors have newly developed the “Port Traffic Management System (PTMS)”. The PTMS provides each ship with the detailed planned routes of all the ships entering/leaving the port. This system also has a function to predict the encounter situations between own ship and other ships in the future. Based on information of the present positions, speeds and planned routes of the own ship and other ships, it is possible to predict when and where the own ship will have dangerous encounters with other ships in the future. The software of PTMS was developed from 2001. Then onboard experiments using small training ships equipped with actual AIS were performed in June 2003. From the results of these onboard experiments, the usefulness of PTMS was clarified. In addition to these onboard experiments, the effectiveness of PTMS was confirmed by comprehensive simulator experiments. In the simulator experiments, captains/pilot maneuvered a training ship/container ship in congested waters using PTMS. [t was assumed that all ships have PTMS and send their planned routes. After the simulator experiments, captains/pilot suggested that it is very beneficial if the optimal route of own ship can be automatically calculated. In response to this suggestion, software to calculate the optimal route of own ship using Dynamic Programming was developed. This software calculates the minimum time route from the present position to the destination keeping the danger of collision against other ships under predetermined level. From the result of calculations for multi-encounter situations, it was confirmed that the developed software can provide safe and time-saving route.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1662-1671
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• 2008

The ERS(Embedded Rail Track system) is constructed in the world due to a slab track system having maintenance free, high structural safety, and deduction of noise and vibration. The ADRI-ERS is developed as Korean type. This paper shows that the design of ADRI-ERS and experiments according to DIN EN 13481-5 and Korea high speed train test guidelines. The ADRI-ERS has high structural safety in pull-out test, longitudinal resistance test, and fatigue test. The design method of ADRI-ERS is proposed by two design constants due to the result of experiments also.

• 동력기계공학회지
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• 제17권6호
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• pp.149-155
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• 2013

Since bio-diesel oil has a merit that it satisfies both demand of substitution for fossil fuel and reduction in carbon dioxide emission, it is widely used in diesel engines by blending in gas oil in small quantity. It is needed to reduce in NOx emission in some way or others if blending ratio of bio-diesel oil is going to increase, because it is demerit that bio-diesel oil emits more NOx emission than gas oil. In this study, it was accomplished to optimize 3 factors what effect on NOx emission as blending ratio of bio-diesel oil, injection timing and common rail pressure with an introduction of a design of experiments, in order to minimize a number of tests. It was cleared that to introduce the design of experiments was very available in NOx optimization.

• 대한의용생체공학회:의공학회지
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• 제28권1호
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• pp.55-65
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• 2007

This paper sought to investigate pupil size variability, pupil size parameters in terms of time domain and frequency domain, the autonomic activity change induced by posture change, degree of sleepiness and cognitive task (math task). With a specially designed pupil image acquisition system in the dark room, these three kinds of experiments were performed to induce a dominant state of sympathetic or parasympathetic activation. Electrocardiogram and pupil size were measured in all the experiments. Based on three experiments, we calculated heart rate variability. In the pupil size analysis, we calculated the mean and standard deviation of pupil size (in time domain), and proposed several frequency bands that exhibit different autonomic activation between different sessions. The results indicate that in terms of heart rate variability, posture change exhibited significant differences but not between sleepiness level, or between cognitive task. Pupil sizes differed only during the postures. And we found some frequency bands that correlated with autonomic activation in each experiment. While heart rate variability reflects posture change that need cardiac control, pupil size variability reflects not only posture induced autonomic activation but sleepiness and cognitive load, which is processed in the brain, in time and frequency domain parameter.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3768-3774
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• 2023

The purpose of the target system for the muon spin rotation, relaxation, and resonance (µSR) facility at the Rare isotope Accelerator complex for ON-line experiments (RAON) is to induce the production of a significant number of surface muons in thermally stable experiments. The manufactured target system was installed at RAON in the Sindong area near Daejeon in 2021. The design was made conservatively with a sufficient margin of safety through ANSYS calculations; however, verification experiments had to be performed on the ANSYS calculations. Because the 600-MeV proton beam has not yet been provided, an alternative way to reproduce the calculation conditions was required. The radio frequency (RF) heating method, which has not yet been applied to the target verification experiment but has several advantages, was used. It was observed that the RF heating method has promise for testing the thermal stability of the target, and whether the target system design process was performed conservatively enough was verified by comparing the RF heating experiments with the ANSYS calculations.