• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.373-376
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• 2007

본 논문에서는 동적 서명인증을 위한 특징 정보로써 서명에서 추출되는 두 점사이의 방향정보와 속력정보로 구분하였다. 방향(모양)에 대한 특징은 인접한 두 좌표점 사이의 36 방향정보를 활용하였고, 속력에 대한 특징은 DTW 방법에서 조정상수(W)를 사용하여 반영되도록 하여 개선된 동적 서명 인증시스템을 구현하였다.

• 대한조선학회논문집
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• 제56권6호
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• pp.473-479
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• 2019

Welding is one of the most popular joining methods and most welding quality estimation methods are executed using joined material. This paper propose welding quality estimation methods using dynamic current, voltage and resistance which are obtained during welding in real time. There are many kinds of welding method. Among them, we focused on the projection welding and gathered dynamic characteristics from two different types of projection welding. For image learning, graphs are drawn using obtained current, voltage and resistance, and the graphs are converted to images. The images are labeled with two sub-categories - normal and defect. For deep learning of images obtained from welding, Convolutional Neural Network (CNN) is applied, and Tensorflow was used as a framework for deep learning. With two resistance welding test datasets, we conclude that the Convolutional Neural Network helps in predicting the welding quality.

• 대한전기학회논문지
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• 제45권4호
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• pp.501-510
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• 1996

The gas-turbine generator of Seo-Incheon combined-cycle plant was tested for derivation of a model for dynamic analysis. Load rejection and AVR step test was performed to get the dynamic response of generator. The parameters of generator/control system model were determined by these measured data. No-load saturation test was performed for the saturation characteristics of the generator under steady state. V-curve test was also performed so as to find exact generator parameters. Q-axis parameters of generator was derived by measuring power angle. AVR and governor constants have been tuned by their oscillatory period and setting time characteristics. The derived parameters of generator control system is verified by one-machine infinite bus system simulation. (author). 7 refs., 20 figs., 5 tabs.

• 한국소음진동공학회논문집
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• 제11권6호
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• pp.208-215
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• 2001

The paper presents both theoretical and experimental study fur dynamic instabilities of a vortical cantilevered pipe with two attached lumped masses conveying fluid. The two attached lumped masses can be considered as valves or some mechanical paras in real pipe systems. Eigenvalue behaviors depending on the flow velocity are investigated for the change of Positions and magnitudes of an attached lumped mass and a tip mass. In order to verify appropriate of numerical solutions, experiments were accomplished. Theoretical predictions have a good agreement with experimental ones.

• KEPCO Journal on Electric Power and Energy
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• 제5권3호
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• pp.165-171
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• 2019

The steam turbine used in nuclear power plant is modeled for the purpose of verification of control system rather than the operator education. The valves, reheater and generator are modeled also and integrated into the simulator. After that, the operation data and the designed data such as heat balance diagram are utilized to identify the model parameters. It was evident that model outputs of developed simulator are very close to the measured operating ones. The simulator within dynamic model was used to verify and validate the whole control system together with field instruments. And the target plant has been operating long time.

• Geomechanics and Engineering
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• 제6권2호
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• pp.117-138
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• 2014

The main focus of the current study is to evaluate the dynamic behavior of a cantilever retaining wall considering backfill and soil/foundation interaction effects. For this purpose, a three-dimensional finite element model (FEM) with viscous boundary is developed to investigate the seismic response of the cantilever wall. To demonstrate the validity of the FEM, analytical examinations are carried out by using modal analysis technique. The model verification is accomplished by comparing its predictions to results from analytical method with satisfactory agreement. The method is then employed to further investigate parametrically the effects of not only backfill but also soil/foundation interactions. By means of changing the soil properties, some comparisons are made on lateral displacements and stress responses. It is concluded that the lateral displacements and stresses in the wall are remarkably affected by backfill and subsoil interactions, and the dynamic behavior of the cantilever retaining wall is highly sensitive to mechanical properties of the soil material.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.759-764
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• 2010

In this study, from the comparison of the results obtained by 3 dimensional dynamic analyses using the inverse-calculated properties and those by calculating using the real earthquake records, the inverse calculation method for obtaining the dynamic properties of rockfill materials was verified. The fundamental frequency of the dam was determined by analyzing the response spectrum of observed records. By repeated dynamic analyses for various shear moduli of rockfill material, the shear moduli in the rockfill zone that satisfy the relationship between the fundamental frequency obtained by analysis of the observed records and that by numerical analyses were determined. Using the determined shear moduli, the 3 dimensional dynamic analyses for the dam were carried out and the result were compared with the real response characteristics on the crest of the dam.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.317-322
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• 1994

The design and performance verification of collocated capacitance sensor system for magnetic bearing is presented. Noncollocation between actuators and sensors may cause unstable rotor behavior. The capacitance sensor is not affected by magnetic field. PCB type capacitance sensor is installed between magnetic bearing polse. so, collocation of sensors and actuators can be achieved. Experiment of sensor's static and dynamic charactistics is conducted. Modeling of the rotor system supported by magnetic bearing is made. And performance comparison between simulation and experiment is showed.

• 한국지진공학회논문집
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• 제17권5호
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• pp.209-217
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• 2013

In order to verify the reliability of numerical site response analysis program, both soil free-field and base rock input motions should be provided. Beside the field earthquake motion records, the most effective testing method for obtaining the above motions is the dynamic geotechnical centrifuge test. However, need is to verify if the motion recorded at the base of the soil model container in the centrifuge facility is the true base rock input motion or not. In this paper, the appropriate input motion measurement method for the verification of seismic response analysis is examined by dynamic geotechnical centrifuge test and using three-dimensional finite difference analysis results. From the results, it appears that the ESB (equivalent shear beam) model container distorts downward the propagating wave with larger magnitude of centrifugal acceleration and base rock input motion. Thus, the distortion makes the measurement of the base rock outcrop motion difficult which is essential for extracting the base rock incident motion. However, the base rock outcrop motion generated by using deconvolution method is free from the distortion effect of centrifugal acceleration.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1160-1165
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• 2008

The development of a new railway vehicle is under progress through the Next Generation High-Speed Rail Development Project in Korea. Its aim is to develope fundamental technology of the vehicle that can run over 400km/h. The new distributed traction bogie system, 'HEMU'(High-speed Electric Multiple Unit), will be used and is different from previously developed high speed railway vehicles. Previous vehicles adopted push-pull type system, which means one traction-car drives rest of the vehicle. Due to the difference, investigation on dynamic behavior and its safety evaluation are necessary, as a part of verification of the design specification. In this paper, current progresses of researches are presented. And the High-Speed Railway vehicle system is evaluated for a dynamic characteristic simulation. Proper models including air-suspension system, wheel-rail, bogie and car-body will be developed according to the vehicle simulation scenario. International safety standard will be applied for final verification of the system. This research can propose a better solution when test running shows a problem in the parts and elements. Finally, the vehicle that has excellent performance will be developed, promoting academic achievement and technical development.