• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.10a
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• pp.14-17
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• 1988

Degradation effects observed in nonvolatile MNOS memory devices with in increasing W/E (Write/Erase) cycling were investigated using n-type MNOS capacitors. The results showed that the density of Si-SiO$_2$ interface states and the conductivity of nitride were increased with W/E cycles, therefore the memory retention characteristics of the MNOS memory devices were degraded. Also, annealing of the degraded devices restored the original Si-SiO$_2$ interface states density, but failed to restore the original nitride conductivity. Based on these experimental results, we found that the degradation of memory retention characteristic was affected by the nitride conductivity rather than by Si-SiO$_2$ interface states.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.274-274
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.242-249
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• 1989

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.61-64
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• 2001

This paper describes a basic study for the classification of cognitive mental states as a basic research of a human-computer interface technique. To recognize the mental states, we obtained 22 subjects’brain waves in course of two types of experiments. One of the experiments is to choose an answer among yes, no or reject buttons, to underlying questions and the other is to select an icon displayed in a monitor screen. After acquiring the brain wave signals, we construct a feature set with the percent power increase for a given segment with respect to that of the reference period. The linear discriminative algorithm is used to classify the cognitive yes/no mental states.

• Journal of Korea Multimedia Society
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• v.18 no.3
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• pp.376-386
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• 2015

Since affective computing has been introduced in 90s, affect recognition technology has achieved substantial progress recently. However, the application of user emotion recognition into software user interface is in its early stages. In this paper, we describe a new approach for developing mobile user interface which could react differently depending on user emotion states. First, an emotion reaction model is presented which determines user interface reactions for each emotional state. We introduce a pair of mappings from user states to different user interface versions. The reacting versions are implemented by a set of variations for a view. Further, we present an authoring framework to help developers/designers to create emotion-aware reactions based on the proposed emotion reaction model. The authoring framework is necessary to alleviate the burden of creating and handling multi versions for views at the development process. A prototype implementation is presented as an extension of the existing authoring tool DAT4UX. Moreover, a proof-of-concept application featuring an emotion-aware interface is developed using the tool.

• Journal of Adhesion and Interface
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• v.22 no.4
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• pp.144-152
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• 2021

Understanding charge transfer across the interface between organic semiconductor and gate insulator gives insight into the development of high-performance organic memory as well as highly stable organic field-effect transistors (OFETs). In this work, we firstly unveil a novel interfacial charge transfer mechanism, in which hole transfer from organic semiconductor to polymer insulator was nonlinearly boosted by localized states coupling. For this, OFETs based on rubrene single crystal semiconductor and Mylar gate insulator were fabricated via vacuum lamination, which allows stable repetition of lamination and delamination between semiconductor and gate insulator. The surfaces of rubrene single crystal and Mylar film were selectively degraded by photo-induced oxygen diffusion and UV-ozone treatment, respectively. Consequently, we found that the interfacial charge transfer and resultant bias-stress effect were nonlinearly boosted by coupling between localized states in rubrene and Mylar. In particular, the small number of localized states in rubrene single crystal provided fluent pathway for interfacial charge transport.

• Korean Journal of Materials Research
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• v.29 no.8
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• pp.463-468
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• 2019

The electrical and interfacial properties of $HfO_2/Al_2O_3$ and $Al_2O_3/HfO_2$ dielectrics on AlN/p-Ge interface prepared by thermal atomic layer deposition are investigated by capacitance-voltage(C-V) and current-voltage(I-V) measurements. In the C-V measurements, humps related to mid-gap states are observed when the ac frequency is below 100 kHz, revealing lower mid-gap states for the $HfO_2/Al_2O_3$ sample. Higher frequency dispersion in the inversion region is observed for the $Al_2O_3/HfO_2$ sample, indicating the presence of slow interface states A higher interface trap density calculated from the high-low frequency method is observed for the $Al_2O_3/HfO_2$ sample. The parallel conductance method, applied to the accumulation region, shows border traps at 0.3~0.32 eV for the $Al_2O_3/HfO_2$ sample, which are not observed for the $Al_2O_3/HfO_2$ sample. I-V measurements show a reduction of leakage current of about three orders of magnitude for the $HfO_2/Al_2O_3$ sample. Using the Fowler-Nordheim emission, the barrier height is calculated and found to be about 1.08 eV for the $HfO_2/Al_2O_3$ sample. Based on these results, it is suggested that $HfO_2/Al_2O_3$ is a better dielectric stack than $Al_2O_3/HfO_2$ on AlN/p-Ge interface.

• Journal of the Korean Society for Library and Information Science
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• v.26
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• pp.167-185
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• 1994

The purpose of this study is to develop the optimal user/librarian interface in information searching. In order to achive the purpose, the 150 unskilled students as subjects have participated in the study. According to the change of the subjects' psychological information states by the access points within the library system, the subjects have been classified into the five types of model: the initial information state, the accepted identification information state, the bibliographic information state, the stack information state, and the location information state. Librarian's searching support is done for 10 minutes at the each access points. To develop the optimal user/librarian interface, the expected values of the models are calculated. The resultants are as follows: 1) The expected value of the initial information states model is 18.94: 2) The expected value of the accepted identification information model is 27.06: 3) The expected value of the bibliographic information state model is 27.06: 4) The expected value of the stack information state model is 22.38: 5) The expected value of the location information state model is 22.38. Those expected values are compared with each other. The model with the lowest expected value is chosen as the optimal user/librarian interface model. In the result, the user's initial information state model of the optimal user/librarian interface in information searching is developed. In order to search the information with the most effect, user must be interfaced with the librarian at his/her own initial information state.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.6
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• pp.436-439
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• 2010

SiC power device possesses attractive features, such as high breakdown voltage, high-speed switching capability, and high temperature operation. In general, device design has a significant effect on the switching characteristics. In this work, we report the effect of the interface states ($Q_f$) on the transient characteristics of SiC DMOSFETs. The key design parameters for SiC DMOSFETs have been optimized by using a physics-based two-dimensional (2-D) mixed device and circuit simulator by Silvaco Inc. When the $SiO_2$/SiC interface charge decreases, power losses and switching time also decrease, primarily due to the lowered channel mobilities. High density interface states can result in increased carrier trapping, or more recombination centers or scattering sites. Therefore, the quality of $SiO_2$/SiC interfaces has a important effect on both the static and transient properties of SiC MOSFET devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.365-365
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• 2010

In this paper, silicon nitride thin films with different silane and ammonia gas ratios were deposited and characterized for the antireflection and passivation layer of high efficiency single crystalline silicon solar cells. As the flow rate of the ammonia gas increased, the refractive index decreased and the band gap increased. Consequently, the transmittance increased due to the higher band gap and the decrease of the defect states which existed for the 1.68 and 1.80 eV in the SiNx films. The reduction in the carrier lifetime of the SiNx films deposited by using a higher $NH_3/SiH_4$ flow ratio was caused by the increase of the interface traps and the defect states in/on the interface between the SiNx and the silicon wafer. The silicon and nitrogen rich films are not suitable for generating both higher carrier lifetimes and transmittance. These results indicate that the band gap and the defect states of the SiNx films should be carefully controlled in order to obtain the maximum efficiency for c-Si solar cells.