• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.912-915
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• 1996

The computed-torque method (CTM) shows good trajectory tracking performance in controlling robot manipulator if there is no disturbance or modelling errors. But with the increase of a payload or the disturbance of a manipulator, the tracking errors become large. So there have been many researches to reduce the tracking error. In this paper, we propose a new control algorithm based on the CTM that decreases a tracking error by generating new reference trajectory to the controller. In this algorithm we used the concept of sliding mode theory and fuzzy system to reduce chattering in control input. For the numerical simulation, we used a 2-link robot manipulator. To simulate the disturbance due to a modelling uncertainty, we added errors to each elements of the inertia matrix and the nonlinear terms and assumed a payload to the end-effector. In this simulation, proposed method showed better trajectory tracking performance compared with the CTM.

• 한국군사과학기술학회지
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• 제13권2호
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• pp.235-242
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• 2010

DSTC(Defense Systems Test Center) in ADD(Agency for Defense Development) performs a test for various kinds of weapon system. In order to provide accurate test measurement data relating to the weapon system's performance with customer, A reliable test process and an objective analysis of the measurement data are required. DSTC is trying to apply CMMI(Capability Maturity Model Integration) Ver 1.2 in a test process. In this paper, we present the result of CMMI Engineering Process Area Modelling of Test Process.

• 한국전기전자재료학회논문지
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• 제30권7호
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• pp.459-462
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• 2017

In this study, we design, model, and analyze a compound generator that combines the axial flux permanent magnet (AFPM,) and radial flux permanent magnet (RFPM), which is expected to increase power generation by allowing the magnets to be placed on the upper, lower, left, and right sides of the same-sized generator. Through the design, modelling, and analysis of AFPM and RFPM compound generators, the generator load evaluation results rated output of 500.25 W and efficiency of 87.60%, respectively, at a rated speed of 600 rpm. By employing this complex generation system,these findings are expected to contribute to the activation of a small power generation system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 전기설비전문위원
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• pp.163-165
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• 2009

Many photovoltaic (PV) systems are being developed and installed. For a PV developer, simulations are required before the experimental testing. However, most simulation tools do not offer data libraries for PV systems, so that some Institutes who try to use such software will be in difficulty. In this paper, simulations of performance and stability have been carried out using the software PSPICE. In this paper, the modelling of solar cell arrays, photovoltaic modules, PV generators, batteries and drive systems is carried out based on mathematical equivalence circuits and available data, and the models are converted into a data library for PSPICE that is user friendly. System variations can be modeled by simple parameter variation. To verify the accuracy of the simulation library, various models were run and compared to known systems.

• Journal of Advanced Marine Engineering and Technology
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• 제18권1호
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• pp.92-100
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• 1994

For generating NC machining data automatically, it is important to handle computer models such as geometric shape data including engineering specifications for the mechanical part to be manufactured. We proposed unique CAM system for a personal computer that can define the geometric shape in an ease manner and machine the sculptured surfaces of a mold cavity. In this paper, the theoretical basis of generation of high precision machining data for a mold cavity is obtained. The first is geometric modelling, and the second is high precision machining with an optimized tool path algorithm satisfying given tolerance limits. Especially, the bicubic Bezier basis function is adopted for a geometric modelling.

• 통합자연과학논문집
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• 제9권4호
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• pp.234-240
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• 2016

Bradykinin receptor B2, a GPCR protein, binds with the inflammatory mediator hormone bradkynin. It plays an important role in cross-talk between the renin-angiotensin system (RAS) and the kinin-kallikrein system (KKS). Also, it is involved in many processes including vasodilation, edema, smooth muscle spasm and pain fiber stimulation. Hence, studuying the structural features of the receptor becomes important. But the unavailability of the three dimensional structure of the protein makes the analysis difficult. Hence we have performed the homology modelling of Bradykinin receptor B2 with 5 different templates. 25 different homology models were constructed. Two best models were selected based on the model validation. The developed models could be helpful in analysing the structural features of Bradykinin receptor B2 and in pathophysiology of various disorders related to them.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.117-121
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• 1990

The control process involving pure time delays presents a continuing challenge to the control system engineer. The nonlinear nature of the delay which can be introduced into the system make the use of conventional control algorithms a poor prospect. The Smith Predictor was developed to alleviate this problem. Unfortunately the quality of control achieved with the Smith Predictor is known to be sensitive to modelling errors. Only recently have researchers attempted to quantify the Smith Predictor controller's robustness to modelling errors. In several studies stability boundaries were plotted as functions of errors in parameters. But the research results address the question of performance of Smith Predictor controllers, In this paper, the Rule based Expert Systems for performance improvement of the Smith Predictor controller are developed.

• 한국정밀공학회지
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• 제13권6호
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• pp.168-176
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• 1996

A diagnosis system which can monitor tool breakage and chipping in real time was developed using a DSP(Digital Signal Processor) board in face milling operation. AR modelling and band energy method were used to extract the feature of tool states from cutting force signals. Artificial neural network embedded on DSP board discriminates different patterns from features got after signal processing. The features extracted from AR modelling are more accurate for the malfunction of a process than those from band energy method, even though the computing speed of the former is slow. From the processed features, we can construct the real time diagnosis system which monitors malfunction by using a DSP board having a parallel processing capability.

• 한국자동차공학회논문집
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• 제8권1호
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• pp.32-39
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• 2000

To optimize the cold start process of a 4-stroke, 8 cylinder Diesel engine, a dynamic simulation model from cranking to idle speed is developed. Physically-based first order starter motor dynamics are used to model the performance of starting process which is very complex. These equations are solved using numerical schemes(Petzold-Gear BDF method) to describe the starting process of diesel engine and to study the effects of starting parameters. The validity of this model is examined by start test. This model can be served as a tool for computer aided control systems design to improve cold improve cold start performance.

• 한국세라믹학회지
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• 제35권12호
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• pp.1257-1265
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• 1998

Hertzian contact tests were used to investigate the evolution of fracturedamage in the coating layer as functions of contact load and coating thickness by studying crack patterns in porcelain on glass-infiltrated alumina bilayer system conceived to simulate the crown structure of a tooth. Cone cracks initiated at the coating top surface without delamination at interface and crack propagation to substrate. Preferentially the cracks made multi-cracks at the coating top surface rather than proceeding to interface. The cracks were highly stabilized with wide ranges between the loads to initiate first cracking and to cause final failure im-plying damage-tolerant capability. Finite element modelling was used to evaluate the stress distribution. Maximum tensile stress were responsible for the cracking at the coating layer and had a profound influence on the crack pattern and fracture damage in the layered structure materials.