• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.5
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• pp.485-489
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• 2015

An accurate large-signal BSIM4 macro model including new empirical bias-dependent equations of the drain-source capacitance and channel resistance constructed from bias-dependent data extracted from S-parameters of RF MOSFETs is developed to reduce $S_{22}$-parameter error of a conventional BSIM4 model. Its accuracy is validated by finding the much better agreement up to 40 GHz between the measured and modeled $S_{22}$-parameter than the conventional one in the wide bias range.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.97.5-97
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• 2002

A sensor modeling via artificial neural network is presented in this paper. The optical sensor has been designed to treasure absolute 3-dimensional positions and orientations of objects in 6-DOF. The method utilizes a triangular pyramidal mirror having an equilateral cross-sectional shape referred as 3-facet mirror. The mirror has three lateral reflective surfaces inclined 45 degrees to its bottom surface. The 3-facet mirror is mounted on the object whose 6-DOF motion is to be measured. As optical components, a He-Ne laser source and three position-sensitive detectors(PSD) are used. The laser beam is emitted from the He-Ne laser source located at the upright position and vertically incident o...

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.948-949
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• 2008

In this paper, an effect on power conversion unit in next generation high-speed train by loss of contact between a contact wire and pantograph supplied electrical power to high-speed train are investigated. One of the most important needs accompanied by increasing the speed of high-speed train is reduced that arc phenomenon by loss of contact brings out EMI. To analysis of conducted EMI source on powering mode of next generation high-speed train, it is necessary electrical modeling system between the contact wire and the pantograph according with loss of contact. Therefore analytical model of a contact wire and a pantograph is constructed to simulate the behaviour of loss of contact. The reliability of the modeling system is verified by simulation implementation on loss of contact.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.310-312
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• 1994

A partial shunt regulator (PSR) which is the power regulator of KOREASAT is modeled. The modeling of the PSR consist of solar array, power circuit, controller. and load models. To realize simple structure. a voltage source of the PSR controller is used the output voltage of the PSR. The model of the PSR has very complex structure with two additional coupled feedback loops. The complex model is simplified to a simple meaningful model with only main feedback control loop. The proposed model is compared to a PSR model with DC voltage source at the PSR controller. The proposed PSR model is verified by comparing the model with SPICE simulation for small signal analysis.

• International Journal of Aerospace System Engineering
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• v.2 no.1
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• pp.18-23
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• 2015

Based on real jobs, this study was carried out the Railway maintenance works in Taiwan. It hopes to use Geographic Information System(GIS) and Building Information Modeling(BIM) for changing the maintenance model from "post-damage repair" to "preventive maintenance". Accordingly, this research will build a Railway Repairing Database that installs all repair data. This database will also connect to GIS so that can be the source of analysis and statistic for repair paln. The main results of research are as follows: I. All data stored on cloud space that raises the ability to manage and plan on repair. II. Simplify the file work and increase the quantity of case data to the manager who can get more reliable source. III. The data offer objective judgment to avoid subjective argument. IV. Add the GIS information to improve the maintenance because of good analisis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.716-717
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• 2017

In this paper, we propose a modeling approach for marine environment monitoring by leveraging open-source software to link IoT and Cloud together. The proposed model can be scale out by employing Apache Hadoop-based time-series database so that it can handle collected data increase with a resource pool of the same computers. It can also support the analyze monitored data of marine environment by visualizing collected data.

• Journal of Power Electronics
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• v.18 no.6
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• pp.1901-1911
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• 2018

This study presents a circuit model for simulating the switching transients of insulated-gate bipolar transistors (IGBTs) with inductive load switching. The modeling approach used in this study considers the behavior of IGBTs and freewheeling diodes during the transient process and ignores the complex semiconductor physics-based relationships and parameters. The proposed circuit model can accurately simulate the switching behavior due to the detailed consideration of device-circuit interactions and the nonlinear nature of model parameters, such as internal capacitances. The developed model is incorporated in an IGBT loss calculation module of an electromagnetic transient simulation program to enable the estimation of switching losses in voltage source converters embedded in large power systems.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.6
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• pp.427-437
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• 1997

Complex terrain which is rather typical topographic character in Korea would greatly influence the dispersion of air pollutant. In this study, we investigated how the complex terrain in the vicinity of the coal-fired plant affects the air dispersion modeling results by using several US EPA models: SCREEN, CTSCREEN, ISCLT3, ISCST3, and RTDM. Screening analysis was followed by long-term analysis, and the plume movement over the terrain was precisely tracked for selected cases. Screening analysis revealed that the highest concentration of sulfur dioxide occurs at the downwind distance of 1.3 km under the unstable conditions with weak winds. However, this highest level of $SO_2$ could be raised by 4 times even in the presence of a hill of 170 m at a distance of 2 to 3 km. Seasonal and annual average concentrations predicted with the ISCLT3, ISCST3, and RTDM models showed a rapid incrase of $SO_2$ levels in front of the high mountains which are located more than 15 km away fromt the source. The highest concentrations predicted with ISCST3 were significantly higher than those with ISCLT3 and RTDM mainly because ISCST3 chooses simple-terrain model calculations for receptors between stack height and plume height. Although the highest levels under the stable conditions were usually found in the areas beyond 15 km or more, their absolute values were not so high due to enough dispersion effects between the source and the receptors.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.4
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• pp.459-476
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• 2013

Receptor models have been rapidly developed to manage the ambient air quality and to establish effective emission reduction strategies. The models are used to identify various emission sources and apportion quantitatively the ambient pollutant mass based on various measured physico-chemical properties of the air pollutants at the receptor site. Many types of receptor models have been applied to estimate source contributions since those provide fundamental information when establishing reasonable environmental policies in Korea and Foreign countries. In this paper, we will introduce the basic concept and principal of the receptor model, various types of existing models with discussing strong and weak points for each model, and performance procedure of PMF model as the most popular model in the world. Further the trends of receptor modeling studies in Korea and other countries were provided. Finally, the improvement directions of the modeling works for the national and local air quality management were suggested in this paper.

• Journal of Drive and Control
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• v.16 no.1
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• pp.45-53
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• 2019

The objective of this study was to design and model the PEM fuel cell excavator with supercapacitor/battery hybrid power source to increase efficiency as well as eliminate greenhouse gas emission. With this configuration, the system can get rid of the internal combustion engine, which has a low efficiency and high emission. For the analysis and simulation, the governing equations of the PEM system, the supercapacitor and battery were derived. These simulations were performed in MATLAB/Simulink environment. The hydraulic modeling of the excavator was also presented, and its model implemented in AMESim and studied. The whole system model was built in a co-simulation environment, which is a combination of MATLAB/Simulink and AMESim software. The simulation results were presented to show the performance of the system.