• Journal of Internet Computing and Services
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• v.8 no.3
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• pp.57-63
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• 2007

Providing the sufficient energy to the mobile device is essential to process the job in distributed wireless network. To solve the restrained conditions of energy problems of mobile devices, this paper suggests the efficient method of processing the distributed job using mobility management in wireless network. Energy consumption can be analyzed using the statistical model and required energy of processing the distributed job in mobile device can be predicted using the mobility management. Therefore, this paper suggests the reliable algorithm to process distributed job through the mobile devices with regular mobility and shows the efficiency of the suggested algorithm.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.164.2-164.2
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• 2014

In order to combine advantages of ZnO thin film transistors (TFTs) with a high on-off ratio and graphene TFTs with extremely high carrier mobility, we present a facile methodology for fabricating ZnO thin film/graphene hybrid two-dimensional TFTs. Hybrid TFTs exhibited ambipolar behavior, an outstanding electron mobility of $329.7{\pm}16.9cm^2/V{\cdot}s$, and a high on-off ratio of $10^5$. The ambipolar behavior of the ZnO/graphene hybrid TFT with high electron mobility could be due to the superimposed density of states involving the donor states in the bandgap of ZnO thin films and the linear dispersion of monolayer graphene. We further established an applicable circuit model for understanding the improvement in carrier mobility of ZnO/graphene hybrid TFTs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.343-353
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• 2018

Most local governments operate Mobility Support Centers to provide transportation convenience for the transportation vulnerable. A Mobility Support Center makes various efforts to improve the mobility of the transportation vulnerable. One of them is the operation of a Special Transportation Vehicle (STV). On the other hand, during implementation, problems, such as insufficient number of vehicles and high demand, have been found. Nevertheless, improving the service by providing a large amount of STV can be a problem in terms of the budget. Therefore, it is necessary to gather opinions of the users and identify the problems during the utilization of a Mobility Support Center. Moreover, it is necessary to improve various services to achieve a better and more comfortable utilization. In this research, SEM was used to analyze the importance of the Mobility Support Center for the transportation vulnerable. The importance and performance drawn and examined through an analysis and questionnaire survey were used to propose IPA results that consider the importance and performance at the same time. In addition, this research also suggest a service improvement priority based on the analysis result. For the analysis, this research conducted a questionnaire survey on the actual users and their guardians who use STV in Cheonan-city, as well as factor analysis and reliability analysis. The results showed that the 'Charge system' is not affected by the service because it is fully satisfied by the low price when compared to public transportation. In addition, 'Vehicle use' is more important than 'Convenience' service. IPA analysis showed that it is necessary to improve the priority, kindness, waiting time, and call center response for the better and more comfortable utilization of Mobility Support Centers for the transportation vulnerable.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.3
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• pp.189-198
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• 2006

A new analytical model has been proposed for predicting the sheet carrier density of Metal insulator Semiconductor High Electron Mobility Transistor (MISHEMT). The model takes into account the non-linear relationship between sheet carrier density and quasi Fermi energy level to consider the quantum effects and to validate it from subthreshold region to high conduction region. Then model has been formulated in such a way that it is applicable to MESFET/HEMT/MISFET with few adjustable parameters. The model can also be used to evaluate the characteristics for different gate insulator geometries like T-gate etc. The model has been extended to forecast the drain current, conductance and high frequency performance. The results so obtained from the analysis show excellent agreement with previous models and simulated results that proves the validity of our model.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.357-362
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• 2019

This paper proposes a model and train method that can real-time detect objects and distances estimation based on a monocular camera by applying deep learning. It used YOLOv2 model which is applied to autonomous or robot due to the fast image processing speed. We have changed and learned the loss function so that the YOLOv2 model can detect objects and distances at the same time. The YOLOv2 loss function added a term for learning bounding box values x, y, w, h, and distance values z as 클래스ification losses. In addition, the learning was carried out by multiplying the distance term with parameters for the balance of learning. we trained the model location, recognition by camera and distance data measured by lidar so that we enable the model to estimate distance and objects from a monocular camera, even when the vehicle is going up or down hill. To evaluate the performance of object detection and distance estimation, MAP (Mean Average Precision) and Adjust R square were used and performance was compared with previous research papers. In addition, we compared the original YOLOv2 model FPS (Frame Per Second) for speed measurement with FPS of our model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1390-1393
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• 2005

The hardening model based on the dislocation mechanics is employed to study the experimentally observed high tensile elongations of NiAl along the [110] orientation at intermediate temperatures. In the hardening model proposed, a mobility of dislocation is assumed to be restricted to glide through the slip plane by forest dislocation and thermally activated cross-slip event. Overall deformation behavior of NiAl was greatly influenced by temperature-dependent dislocation mobility that both experimental and simulated yield stresses decreased as temperature increased. The results of simulation showed anomalous hardening behaviors analogous to those of experiment at certain circumstances. This behavior occurred due to the hardening contributions generated by cross-slip events that disable the dislocation motion in the primary slip systems. By comparing simulation results with experiments, it is confirmed that the proposed hardening model can represent anomalous tensile elongations due to the hardening by forest dislocations and cross-slip events.

• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.197-203
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• 2004

In mobile network, the maintenance o( host grouping or the multicast delivery tree for multicasting algorithm becomes a major issues. In this paper, we explore the issues of mobile Multicast scheme using Mobile-IPv6, and addresses case when a mobile host is a source as well as a recipient of a given multicast operation using MLD(Multicast Listener Discovery) scheme, and the proposed MLD-based multicasting protocol asks its HA(Home Agent) to stop forwarding multicast for group using tunneling. We examine and compare our model to existing approaches by proposed cost model, and observe an improved ferformacne.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.433-437
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• 2005

The goal of our research is to develop a formal modeling methodology for supervisory and controlling systems that have artificially intelligent features. This approach is agent-based and central to the development of the model of mobility agent considering reactivity for real-time purpose and deliberation for optimal realization and safe-fail problems for critical systems like Intelligent Transportation Systems by high-level Petri net. By using nets within nets we investigate the concurrency of the system and the agent in one model without losing the needed abstraction, and synchronous channels are introduced to denote the coordination and communication. Finally an example is demonstrated.

• Journal of Information Display
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• v.10 no.4
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• pp.143-148
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• 2009

The theoretical current density equations for organic semiconductors was derived according to the internal carrier emission equation based on the diffusion model at the Schottky barrier contact and the mobility equation based on the field dependence model, the so-called "Poole-Frenkel mobility model." The electric field becomes constant because of the absence of a space charge effect in the case of a higher injection barrier height and a lower sample thickness, but there is distribution in the electric field because of the space charge effect in the case of a lower injection barrier height and a higher sample thickness. The transition between the injection- and bulk-limited currents was presented according to the Schottky barrier height and the sample thickness change.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.3 s.333
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• pp.9-16
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• 2005

The mobility in strained Si inversion layer on $Si_{1-x}Ge_x$ is calculated considering a quantum effect(subband energy and wavefunction) in inversion layer and relaxation time approximation. The quantum effect in inversion layer is obtained by using self-consistent calculation of $Schr\ddot{o}dinger$ and Poisson equations. For the relaxation time, intravalley and intervalley scatterings are considered. The result shows that the reason for the enhancement in mobility as Ge mole fraction increases is that the electron mobility in 2-폴드 valleys is about 3 times higher than that of 4-폴드 valleys and most electrons are located in 2-폴드 valleys as Ge mole fraction increases. Meanwhile, for the phonon-limited mobility the fitting to experimental data, Coulomb and surface roughness mobilities are included in total mobility, Deformation potentials are selected for the calculated effective field, temperature, and Ge mole fraction dependent mobilities to be fitted to experimental data, and then upgraded data can be obtained by considering nonparabolicity in Si band structure.