• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.425-426
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• 2006

This study proposes a new simulation method of high speed rotor system with the dynamic model using multi body dynamic analysis tool and with a new phase modulating technique as a system control algorithm. A dynamic model of high speed rotor system was built by, ADAMS, commercial multi body dynamic program. The phase modulating technique is a new control algorithm for a rotor system. This algorithm can control system using an adaptive proportional gain and an adaptive phase which are obtained from periodical input signal. To make control system, a ADAMS model and component parameters and phase controller was composed by Matlab Simulink And simulate it.

• 한국연소학회:학술대회논문집
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• 1998.10a
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• pp.165-170
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• 1998

Turbulent nonpremixed $H_2$-air jet flames are numerically investigated using the joint PDF model. The reaction progress variable is derived by assuming the radicals 0, H, and OH to be in partial equilibrium and additional species $HO_2$ and $H_2O_2$ in steady state. The model is extended to npnadiabatic flame by introducing additional variable for the transport of enthalpy and radiative source term is calculated using a local, geometry independent model. In terms of flame structure and NO formation, the predicted results are favorably agreed with experimental data. The effects of nonequilibrium chemistry and radiative heat loss on the thermal NO formation are discussed in detail.

• The Journal of Information Systems
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• v.16 no.4
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• pp.157-176
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• 2007

Most of the Information Systems(IS) literature has focused on utilitarian or hedonic Information Technology(IT) to explain and predict IT adoption and use. This study investigates the relationships among individuals' beliefs and intention to use of movie website, which has both utilitarian and hedonic characteristics simultaneously. As a theoretical background, this study adopts Technology Acceptance Model(TAM) and Motivation Theory, in which the former is well-known as a theory of IT adoption and use in IS field, and the latter is famous for a theory of individual's behavior in organizational behavior field. With 153 responses, five hypotheses are tested by using structured equation model. The results show that perceived ease of use positively influences perceived usefulness and perceived enjoyment, and that all individuals' beliefs have a positive impact on intention to use of movie web-site. Based upon the study results, movie website's managers and professionals can plan and conduct their courses of action effectively for users' continuous visits on their operating website.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.780-783
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• 2008

This study developed a model that could calculate roughness using Manning's and Chezy coefficient for Yangjae-stream. The estimated roughness by model developed was used for roughness coefficient in the stream without water level-discharge data. Roughness coefficient was estimated using assumed and calculated water level about each discharge scale by unsteady flow analysis. As a result, error of water surface level by model was shown 1.29m, it was shown that the flow resistance tends to increase with the desity of vegetation.

• Journal of the Korean Society of Safety
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• v.24 no.1
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• pp.69-77
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• 2009

This paper reports the aging driver traffic accident severity modeling results. For the modeling, Poisson regression approach is applied using the data set obtained from the Korea Transportation Safety Authority's simulator-based driver aptitude test results. The test items include the estimations of moving objects' speed and stopping distance, drivers' multi-task capability, and kinetic depth perception and so on. The resulting model with the response variable of equivalent property damage only(EPDO) indicated that EPDO is significantly influenced by moving objects' speed estimation and drivers' multi-task capabilities. More interestingly, a comparison with the younger driver model revealed that the degradation of such capabilities may result in severer crashes for older drivers as suggested by the higher estimated parameters for the older driver model.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.555-560
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• 2013

A cost analysis method for pretreament processes of a large scale seawater desalination plant was considered using a cost estimation model, WaTER (Water Treatment Estimation Routine). This model is based on cost functions of U.S. EPA to conduct economic analysis of water treatment facilities. A virtual seawater desalination plant which has pretreatment production capacity of $100,000m^3$ per day was chosen as a model plant. Dual media filtration and microfiltration systems were compared as pretreatment process, and the following reverse osmosis process was modeled. As a result, microfiltration showed a price competitiveness in condition of operating with reverse osmosis process by reducing the loads of water treatment and membrane cleaning despite it's high annual cost.

• Knowledge Management Research
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• v.19 no.4
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• pp.99-118
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• 2018

Recently, individuals are interested in a variety of products and services based on artificial intelligence. Among those products and services, an intelligent personal assistants are attracting many attention from IT companies as a next generation platform. Thus, the main purpose of this study is to investigate effects of intelligent personal assistant's benefits on user's value formation and adoption behavior based on Value-based Adoption Model. In addition, the moderating effect of personal innovativeness is examined through empirical analysis. Based on the analysis with the data from actual users, the results show that usefulness, enjoyment, technicality and cost advantage have significant influences on perceived value and correspondingly have an effect on intention to adopt. Personal innovativeness is related to the relationship between perceived value and intention to adopt. These findings may provide important insights to the relevant field regarding the use and spread of intelligent personal assistants.

• Architectural research
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• v.23 no.1
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• pp.1-10
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• 2021

Project management information systems (PMIS) have been implemented to support cooperation among the participants of construction projects. Unlike other information systems used by members from an organization with similar culture and business environment, the PMIS are members from one-off fragmented project organization with diverse professional background. Successful operation is significantly affected by the tendencies of client's side and individual awareness of participants. In this regard, it is imperative to evaluate the success of the system based on the individual characteristics of PMIS users. Thus, this study proposes a method for determining the system success by analyzing the extent of the effects of system factors such as System Quality, Information Quality, and Service Quality and individual factors such as a user's IT application ability, Extrinsic Motivation to achieve User Satisfaction, and loyalty. Accordingly, a structural equation model (SEM), an effective tool to examine of the comprehensive structure of a causal relationship, is applied for analysis because the internal awareness of individuals is established as a variable.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.9
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• pp.124-129
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• 1997

The purpose of this study is to predict the stability and frequency response of multipurpose vehicle. The vehicle model has seven degrees of freedom. The motion equations are derived by using Lagrangian equation and linearized. The positions of eigenvalues of model which are dominated by lateral velocity, yaw rate, roll rate of sprung mass are used to predict the stability of motion. The resonse of sprung mass to steering wheel is simulated in time domain. It is predicted that the roll response of sprung mass would rather be improved by modifying the position of eigenvalues. The responses of sprung mass to steering wheel are also simulated in frequency domain. The magnitude and phase plots of gains are evaluated in driver's steering input frequency range.

• Journal of Biosystems Engineering
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• v.35 no.1
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• pp.1-9
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• 2010

A mathematical model was developed to predict the fuel consumption rate consumed by agricultural tractors under arbitrary loaded conditions. The model utilizes the measured data on the fuel consumptions at the full load and at the rated engine speed with partial loads, which can easily be obtained from the official OECD tractor test reports. It was found from the analysis of the measured fuel consumption data that the fuel consumptions at two different speeds does not change with power. The model was developed based on this fact and validated with the measured data of the 159 tractor test reports. The fuel consumptions predicted by the model were compared with those measured under the partially loaded conditions specified in the official OECD tractor test code II. The percent errors of the predicted fuel consumptions were in a range from 0.36 to 2.86% which assured that the developed fuel consumption model can be used practically to predict the fuel consumptions at any speed and power combinations. It was also shown that the developed model predicts the fuel consumption rate better than the Grisso's model.