• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.148-151
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• 1993

Load models for the analysis and simulation of power system are often introduced when the more accurate result is required. This work presents a single expressed load model as T-equivalent circuit of induction motor, for the composite characteristics of various loads. The parameters of the proposed load model are identified based on the system identification method as Recursive Least Square identification method. Case study results show the accuracy of proposed load model, and compared with some field measurements.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.9-16
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• 2006

The present study is to simulate coolant flow in IC engine cooling passages under subcooled nucleate boiling conditions and investigate thermal stress analysis of the solid part. To consider nucleate boiling heat transfer effect, Chen's empirical formula is used through user subroutine programing in CFD code and then nucleate boiling model is compared with Robinson's experimental results, which shows reasonable agreement. This Chen's nucleate boiling model is applied to single cylinder IC engine model and we do cylinder liner thermal stress analysis using commercial FEM code.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.1
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• pp.89-98
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• 2004

In this paper, we develope a dispersion model based on the Generalized Langevin Model. Thomson's well-mixed condition is the well known criterion to determine particle dispersion. But, it has 'non-uniqueness problem'. To resolve this, we adopt a turbulent model which is a new approach in this field of study. Our model was greatly simplified under the self-similarity condition, leaving model only two model constants $C_{0}$ and ${\gamma}$$_{5}$ that control the dispersion and spin which measures rotational property of the Lagrangian particle trajectory. We investigated the sign of spin as well as magnitude by using the Direct Numerical Simulation. Model calculations were performed on the neutrally stable boundary layer flow. We found that spin has weak effect on the particle dispersion but it shows the significant effect on the horizontal flux compared to the zero-spin model.

• Journal of Mechanical Science and Technology
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• v.20 no.11
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• pp.1891-1897
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• 2006

In this study, a new model to predict the effective elastic constants of composites with spherical fillers is proposed. The original Eshelby model is extended to a finite filler volume fraction without using Mori-Tanaka's mean field approach. When single filler is embedded in the matrix, the effective elastic constants of the composite are computed. The composite is in turn considered as a new matrix, where new single filler is again embedded in the matrix. The predicted results by the present model with a series of embedding procedures are compared with those by Mori-Tanaka, self-consistent, and generalized self-consistent models. It is revealed through parametric studies such as stiffness ratio of the filler to the matrix and filler volume fraction that the present model gives more accurate predictions than Mori-Tanaka model without using the complicated numerical scheme used in self-consistent and generalized self-consistent models.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.2 s.140
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• pp.98-104
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• 2005

The mathematical models of hydrodynamic force and moment acting on a ship at low speed range should be established differently from the ones at nominal cruising speed range since a ship moves with large drift angle or rotates in a stationary position. We modified widely used Yoshimura's cross flow model in order to apply the system identification method to estimate parameters in the model. The apparatus and the procedure of free running model test were suggested so that the parameters in the model be estimated. The validity of our proposing modified model and test procedure was confirmed by comparison with the results of simulated model test.

• Journal of Korea Multimedia Society
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• v.22 no.3
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• pp.349-356
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• 2019

When a prescription change occurs in the hospital depending on a patient's improvement status, pharmacists directly classify manually returned pills which are not taken by a patient. There are hundreds of kinds of pills to classify. Because it is manual, mistakes can occur and which can lead to medical accidents. In this study, we have compared YOLO, Faster R-CNN and RetinaNet to classify and detect pills. The data consisted of 10 classes and used 100 images per class. To evaluate the performance of each model, we used cross-validation. As a result, the YOLO Model had sensitivity of 91.05%, FPs/image of 0.0507. The Faster R-CNN's sensitivity was 99.6% and FPs/image was 0.0089. The RetinaNet showed sensitivity of 98.31% and FPs/image of 0.0119. Faster RCNN showed the best performance among these three models tested. Thus, the most appropriate model for classifying pills among the three models is the Faster R-CNN with the most accurate detection and classification results and a low FP/image.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.157-165
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• 2016

Among high-tech products, the mobile phone has experienced a rapid rate of innovation and a shortening of its product life cycle. The shortened product life cycle poses major challenges to those involved in the creation of forecasting methods fundamental to strategic management and planning systems. This study examined whether the best model applies to the entire diffusion life span of a mobile phone. Mobile phone sales data from a specific mobile service provider in Korea from March of 2013 to August of 2014 were analyzed to compare the performance of two S-shaped diffusion models and two non-linear regression models, the Gompertz, logistic, Michaelis-Menten, and logarithmic models. The experimental results indicated that the logistic model outperforms the other three models over the fitted region of the diffusion. For forecasting, the logistic model outperformed the Gompertz model for the period prior to diffusion saturation, whereas the Gompertz model was superior after saturation approaches. This analysis may help those estimate the potential mobile phone market size and perform inventory and order management of mobile phones.

• Korean journal of communication and information
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• v.37
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• pp.73-99
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• 2007

The study's purpose is to present model for constructing of media education's curriculum. The concept and goal of media education have changed by various media education's paradigm historically. Also this changed the content and the goal of the media education. Curriculum model of media education is various by the nation. AS so the study analyzed the media education's curriculum model to be applying in USA, United British, German, Australia, Canada. Through this, the model for constructing of media education' curriculum is presented. The curriculum model helps to be executed systematically media education in Korea. According to the result, The model is composed of the goal and content. The goal of media education is composed of media knowledge, media appreciation, media analyze, media production. The content of media education is composed of Media, Text, User.

• Asia pacific journal of information systems
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• v.15 no.4
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• pp.109-133
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• 2005

The purpose of this study is to develop and validate a model of firm's IT capability based on IT resources such as IT infrastructure, IT personnel, and IT routine. To do this, the study defined IT capability as a third-order factor model and identified three conceptual dimensions of IT capability: IT infrastructure flexibility, IT personnel expertise, IT resource management capability, IT resource management capability indicates a capacity generated by IT routines, a new IT resource type identified in this study. The validity of the proposed model is evaluated with 243 firm level data using LISREL. The results of confirmatory factor analysis(CFA) demonstrated that the model is highly reliable and valid. Additionally, it was found that IT routines have a high potential as a new IT resource category.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3179-3189
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• 1999

In this paper, different methods of integrating heterogeneous network information systems into the Web are observed by comparing a cliented Java CGI model with a server-oriented CGI model. In addition, a load balanced(LB, for short) CGI model is proposed, which combines two models and decides its course of action depending on the load state of the web server, and compared with the other two models. Performance evaluation models for three models are also presented. The results of computer simulations indicate that the LB CGI model performs consistently well irrespective of system load or server performance.