• 한국국방경영분석학회지
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• 제8권1호
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• pp.71-76
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• 1982

A procedure is established for combining a regression model and a time series model to fit to a set of autocorrelated data. This procedure is based on an iterative method to compute regression parameter estimates and time series parameter estimates simultaneously. The time series model which is discussed is basically AR(p) model, since MA(q) model or ARMA(p,q) model can be inverted to AR({$\infty$) model which can be approximated by AR(p) model. The procedure discussed in this articled is applied in general to any combination of regression model and time series model.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.29-32
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• 1999

In this study, the time delay model were simulated using the well-known AR model. Frequency response of the time delay model can be obtained by mapping AR model to JTC model in the time domain. That is, from the few measurement data in JTC model, the channel frequency response can be obtained by the estimation of AR model parameters. From this channel frequency response, the time delay model can be obtained using Fourier transformation. To prove the validity of the suggested method, three models of JTC were shown and analyzed.

• 대한산업공학회지
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• 제40권3호
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• pp.283-290
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• 2014

In the flat panel display industry, to meet production target quantities and the deadline of production, the scheduler and dispatching systems are major production management systems which control the order of facility production and the distribution of WIP (Work In Process). Especially the delivery time is a key factor of the dispatching system for the time when a lot can be supplied to the facility. In this paper, we use survival analysis methods to identify main factors of the delivery time and to build the delivery time forecasting model. To select important explanatory variables, the cox proportional hazard model is used to. To make a prediction model, the accelerated failure time (AFT) model was used. Performance comparisons were conducted with two other models, which are the technical statistics model based on transfer history and the linear regression model using same explanatory variables with AFT model. As a result, the mean square error (MSE) criteria, the AFT model decreased by 33.8% compared to the statistics prediction model, decreased by 5.3% compared to the linear regression model. This survival analysis approach is applicable to implementing the delivery time estimator in display manufacturing. And it can contribute to improve the productivity and reliability of production management system.

• 드라이브 ㆍ 컨트롤
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• 제16권1호
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• pp.22-28
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• 2019

This paper develops ABS braking real - time simulator to develop vehicle braking system by simulation. Recently, real-time simulation is widely used in the development of vehicles to decrease development time. In the field of electronic braking, real-time simulation is actively underway. In order to simulate electronic braking model in real time, a vehicle model, a hydraulic model, and a control S/W model are required. These models must be calculated in one platform. Therefore, in this paper, a vehicle model composed of CarSim and a hydraulic model composed of SimulationX using S/W in actual ABS controller was developed as a Simulink model base and linked with Matlab real time model. Using this real-time model, design effects of the electronic braking controller were simulated according to road surface condition to verify its operability.

• 융복합기술연구소 논문집
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• 제4권2호
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• pp.17-21
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• 2014

This paper presents the effects of the time delay on the stability of the haptic system that includes a virtual wall and a first-order-hold method. The model of a haptic system includes a haptic device model with a mass and a damper, a virtual wall model, a first-order-hold model and a time delay model. In this paper, the time delay is considered as the computational time delay that is assumed to be as much as the sampling time. As the time delay increases, the maximal available stiffness of a virtual wall model is reduced reversely. The relation among the time delay and the maximum available stiffness, the mass and the damper of the haptic device are analyzed using the MATLAB simulation.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2004년도 춘계학술대회 논문집
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• pp.109-117
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• 2004

In this paper, we consider the aortic sinus baroreceptor, which is the most representative baroreceptor sensing the variance of pressure in the cardiovascular system, and propose heart activity control model to observe the effect of delay time in heart period and stroke volume under the regulation of baroreflex in the aortic sinus. The proposed heart activity baroreflex regulation model contains electric circuit sub-model. We constituted the time delay sub-model to observe sensitivity of heart activity baroreflex regulation model by using the variable value to represent the control signal transmission time from the output of baroreflex regulation model to efferent nerve through central nervous system. The simulation object of this model is to observe variability of the cardiovascular system by variable value in time delay sub-model. As simulation results, we observe three patterns of the cardiovascular system variability by the time delay, First, if the time delay over 2.5 second, aortic pressure and stroke volume and heart rate is observed nonperiodically and observed. Finally, if time delay under 0.1 second, then heart rate and aortic pressure-heart rate trajectory is maintained in stable state.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.807-810
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• 1997

Digital control of robot manipulator employs discrete-time robot models. It is important to explore effective discrete-time robot models and to analyze their properties in control system designs. This paper presents a new type discrete-time robot model. The model is derived by using trapezoid rule to approximate the convolution integral term, then eliminating nonlinear force terms from robot dynamical equations. The new model obtained has very simple structure, and owns the properties of independence to the nonlinear force terms. According to evaluation criteria, three aspects of the model properties: model accuracy, model validity range and model simplicity are examined and compared with commonly used discrete-time robot models. The validity of the proposed model and its advantages to control system designs are verified by simulation results.

• 한국기계기술학회지
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• 제13권3호
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• pp.17-23
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• 2011

To estimate fuel consumption of a vehicle, a car can be tested on chassis dynamometer. In this case, test causes a lot of time and money. To predict the fuel efficiency of vehicles in the design stage or early stage of development, the development of computer simulation model is necessary. Using simulation to predict the fuel consumption, the driving model which consists of time-velocity profile and time-grade profile is necessary In this study, vehicle model is developed in MatLab/simulink to estimate real driving fuel consumption rate with time-velocity profile, time-shift gear profile and time-grade profile. Vehicle model consists of driver model, engine model, power train model, and so on. On-road vehicle tests to verify the vehicle model are carried out for analyzing the result of simulation and comparing with those of the experiments.

• 한국정보처리학회논문지
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• 제4권12호
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• pp.2947-2959
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• 1997

시간지원 데이터 모텔은 시간 의미를 데이터 모델에 추가하여 시간에 따라 변화된 정보를 처리할 수 있는 데이터 모델이다. 시간지원 데이터 모델은 실세계에서 사건이 발생한 시간인 유효시간을 지원하는 데이터 모델과 데이터가 수록된 시간을 지원하는 거래시간 데이터 모델 그리고 거래시간과 유효시간을 모두 지원하는 이원시간 데이터 모델이 있다. 대부분의 시간지원 데이터 모델은 관계형 모델을 확장하여 시간지원 데이터를 처리할 수 있도록 설계된다. 시간지원 데이터 모델의 두부류는 시간을 결합하는 단위에 따라 튜플 타임 스탬프와 속성 타임 스탬프의 두 가지 형식이 있다. 본 논문에서는 기존의 데이터 모델에서 시간추가를 위한 기본적인 시간 개념과 시간지원 데이터 모델을 위한 고려사항을 설명하고 시간지원 데이터 모텔을 지원시간에 따라 비교하였다. 또한 유효시간이 지원되는 시간 지원 집계에 적합한 데이터 모델을 제안하고 그 성능을 분석 하였다．

• 정보학연구
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• 제9권3호
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• pp.77-89
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• 2006

The event study analyzes returns around event date at a time. Event study provides estimation periods and cumulative returns. Stock split announcements are generally associated with positive abnormal returns. It is important to investigate the responses of stocks to new information contained in the announcements of stock splits. So It is important to study the long term performance in the case of Stock Split. This Study forced to two approach method in evaluating the performance, the event time portfolio approach and calendar time portfolio approach. The event time portfolio approach exists the CAR model, BHAR model and WR model. And the calendar time portfolio approach has the 3 factor model, 4 factor model, CTAR model, and RATS model.